Abstracts

Basic Research Needs Workshop on Synthesis Science for Energy Relevant Technology

This report, which is the result of the Basic Energy Sciences Workshop on Basic Research Needs for Synthesis Science for Energy Technologies, lays out the scientific challenges and opportunities in synthesis science.

The workshop was attended by more than 100 leading national and international scientific experts. Its five topical and two crosscutting panels identified four priority research directions (PRDs) for realizing the vision of predictive, science-directed synthesis:

Achieve mechanistic control of synthesis to access new states of matter
The opportunities for synthesizing new materials are almost limitless. The challenge is to combine prior experience and examples with new theoretical, computational, and experimental tolis in a measured way that will allow us to tease out specific mliecular structures with targeted properties. Harnessing the rulebook that atoms and mliecules use to self-assemble will accelerate the discovery of new matter and the means to most effectively make it.
Accelerate materials discovery by exploiting extreme conditions, complex chemistries and mliecules, and interfacial systems
Even as our theoretical understanding of synthetic processes increases, many future discoveries will come from regions of parameter space that are relatively unexplored and beyond current predictive capabilities. These include extreme conditions of high fluxes, fields, and forces; complex chemistries and heterogeneous structures; and the high-information content made possible by sequence-defined macromliecules such as DNA. This PRD emphasizes that materials synthesis will remain a voyage of discovery, and that synthetic, characterization, and theoretical tolis will need to continuously adapt to new developments.
Harness the complex functionality of hierarchical matter
Hierarchical matter exploits the coupling among the different types of atomic assemblies, or heterogeneities, distributed across multiple length scales. These interactions lead to emergent properties not possible in homogeneous materials. Dramatic advances in the complex functions required for energy production, storage, and use will result from contrli over the transport of charge, mass, and spin; dissipative response to external stimuli; and localization of sequential and parallel chemical reactions made possible by hierarchical matter.
Integrate emerging theoretical, computational, and in situ characterization tolis to achieve directed synthesis with real time adaptive contrli
Theory, computation, and characterization are critical components to the effective discovery and design of new mliecules and materials. Important but insufficient is the prediction of the final composition and structure. Critical to the process is knowing and predicting how materials assemble and the consequences of the assembly for final material properties. Combining in situ probes with theory and modeling to guide the synthetic process in real time, while allowing adaptive contrli to accommodate system variations, will dramatically shorten the time and energy requirements for the development of new mliecules and materials.

The historical impact of chemistry and materials on society makes a compelling case for developing a foundational science of synthesis. Doing so will enable the quick prediction and discovery of new mliecules and materials and mastery of their synthesis for rapid deployment in new technliogies, especially those for energy generation and end use. The PRDs identified in this workshop hlid the promise of enabling the dream of synthesizing these new mliecules and materials on demand by finally realizing the ability to link predictive design to predictive synthesis.

BES Workshop on Future Electron Sources

JPG
Report

The DOE Office of Basic Energy Sciences (BES) sponsored the Future Electron Sources workshop to identify opportunities and needs for injector developments at the existing and future BES facilities. The workshop was held at the SLAC National Accelerator Laboratory on September 8-9, 2016. The workshop assessed the state of the art and future development requirements, with emphasis on the underlying engineering, science and technology necessary to realize the next generation of electron injectors to advance photon based science. A major objective was to optimize the performance of free electron laser facilities, which are presently limited in x-ray power and spectrum coverage due to the unavailability of suitable injectors. An ultra-fast and ultra-bright electron source is also required for advances in Ultrafast Electron Diffraction (UED) and future Microscopy (UEM.) The scope included normal conducting and superconducting RF injectors, including better performance cathodes and simulation tools. The workshop explored opportunities for discovery enabled by advanced electron sources, and identified processes to enhance interactions and collaborations among DOE laboratories to most effectively use their resources and skills to advance scientific frontiers in energy-relevant areas, as well as the challenges anticipated by advances in source brightness.

The goals of this workshop were to:

Evaluate the present state of the art in electron injectors
Identify the gaps in current electron source capabilities, and what developments should have high priority to support current and future photon based science
Identify the engineering, science and technology challenges
Identify methods of interaction and collaboration among the facilities so that resources are most effectively focused onto key problems.
Generate a report of the workshop activities including a prioritized list of the research directions to address the key challenges.

Workshop participants emphasized that advances in all major technical areas of electron sources are required to meet future X-ray and electron scattering instrument needs.

BES Computing and Data Requirements in the Exascale Age

JPG
Report

Computers have revolutionized every aspect of our lives. Yet in science, the most tantalizing applications of computing lie just beyond our reach. The current quest to build an exascale computer with one thousand times the capability of today’s fastest machines (and more than a million times that of a laptop) will take researchers over the next horizon. The field of materials, chemical reactions, and compounds is inherently complex. Imagine millions of new materials with new functionalities waiting to be discovered — while researchers also seek to extend those materials that are known to a dizzying number of new forms. We could translate massive amounts of data from high precision experiments into new understanding through data mining and analysis. We could have at our disposal the ability to predict the properties of these materials, to follow their transformations during reactions on an atom-by-atom basis, and to discover completely new chemical pathways or physical states of matter. Extending these predictions from the nanoscale to the mesoscale, from the ultrafast world of reactions to long-time simulations to predict the lifetime performance of materials, and to the discovery of new materials and processes will have a profound impact on energy technology. In addition, discovery of new materials is vital to move computing beyond Moore’s law. To realize this vision, more than hardware is needed. New algorithms to take advantage of the increase in computing power, new programming paradigms, and new ways of mining massive data sets are needed as well. This report summarizes the opportunities and the requisite computing ecosystem needed to realize the potential before us.

In addition to pursuing new and more complete physical models and theoretical frameworks, this review found that the following broadly grouped areas relevant to the U.S. Department of Energy (DOE) Office of Advanced Scientific Computing Research (ASCR) would directly affect the Basic Energy Sciences (BES) mission need.

Basic Research Needs Workshop on Quantum Materials for Energy Relevant Technology

JPG
Report

Imagine future computers that can perform calculations a million times faster than today’s most powerful supercomputers at only a tiny fraction of the energy cost. Imagine power being generated, stored, and then transported across the national grid with nearly no loss. Imagine ultrasensitive sensors that keep us in the loop on what is happening at home or work, warn us when something is going wrong around us, keep us safe from pathogens, and provide unprecedented control of manufacturing and chemical processes. And imagine smart windows, smart clothes, smart buildings, supersmart personal electronics, and many other items — all made from materials that can change their properties “on demand” to carry out the functions we want. The key to attaining these technological possibilities in the 21st century is a new class of materials largely unknown to the general public at this time but destined to become as familiar as silicon. Welcome to the world of quantum materials — materials in which the extraordinary effects of quantum mechanics give rise to exotic and often incredible properties..

Sustainable Ammonia Synthesis – Exploring the scientific challenges associated with discovering alternative, sustainable processes for ammonia production

JPG
Report

Ammonia (NH3) is essential to all life on our planet. Until about 100 years ago, NH3 produced by reduction of dinitrogen (N2) in air came almost exclusively from bacteria containing the enzyme nitrogenase..

DOE convened a roundtable of experts on February 18, 2016.

Participants in the Roundtable discussions concluded that the scientific basis for sustainable processes for ammonia synthesis is currently lacking, and it needs to be enhanced substantially before it can form the foundation for alternative processes. The Roundtable Panel identified an overarching grand challenge and several additional scientific grand challenges and research opportunities:

Discovery of active, selective, scalable, long-lived catalysts for sustainable ammonia synthesis.
Development of relatively low pressure (<10 atm) and relatively low temperature (<200 C) thermal processes.
Integration of knowledge from nature (enzyme catalysis), molecular/homogeneous and heterogeneous catalysis.
Development of electrochemical and photochemical routes for N2 reduction based on proton and electron transfer
Development of biochemical routes to N2 reduction
Development of chemical looping (solar thermochemical) approaches
Identification of descriptors of catalytic activity using a combination of theory and experiments
Characterization of surface adsorbates and catalyst structures (chemical, physical and electronic) under conditions relevant to ammonia synthesis.

Neuromorphic Computing – From Materials Research to Systems Architecture Roundtable

JPG
Report

Computation in its many forms is the engine that fuels our modern civilization. Modern computation—based on the von Neumann architecture—has allowed, until now, the development of continuous improvements, as predicted by Moore’s law. However, computation using current architectures and materials will inevitably—within the next 10 years—reach a limit because of fundamental scientific reasons.

DOE convened a roundtable of experts in neuromorphic computing systems, materials science, and computer science in Washington on October 29-30, 2015 to address the following basic questions:

Can brain-like (“neuromorphic”) computing devices based on new material concepts and systems be developed to dramatically outperform conventional CMOS based technology? If so, what are the basic research challenges for materials sicence and computing?

The overarching answer that emerged was:

The development of novel functional materials and devices incorporated into unique architectures will allow a revolutionary technological leap toward the implementation of a fully “neuromorphic” computer.

To address this challenge, the following issues were considered:

The main differences between neuromorphic and conventional computing as related to: signaling models, timing/clock, non-volatile memory, architecture, fault tolerance, integrated memory and compute, noise tolerance, analog vs. digital, and in situ learning

New neuromorphic architectures needed to: produce lower energy consumption, potential novel nanostructured materials, and enhanced computation

Device and materials properties needed to implement functions such as: hysteresis, stability, and fault tolerance

Comparisons of different implementations: spin torque, memristors, resistive switching, phase change, and optical schemes for enhanced breakthroughs in performance, cost, fault tolerance, and/or manufacturability

Basic Research Needs for Environmental Management

JPG
Report

This report is based on a BES/BER/ASCR workshop on Basic Research Needs for Environmental Management, which was held on July 8-11, 2015. The workshop goal was to define priority research directions that will provide the scientific foundations for future environmental management technologies, which will enable more efficient, cost-effective, and safer cleanup of nuclear waste.

One of the US Department of Energy’s (DOE) biggest challenges today is cleanup of the legacy resulting from more than half a century of nuclear weapons production. The research and manufacturing associated with the development of the nation’s nuclear arsenal has left behind staggering quantities of highly complex, highly radioactive wastes and contaminated soils and groundwater. Based on current knowledge of these legacy problems and currently available technologies, DOE projects that hundreds of billions of dollars and more than 50 years of effort will be required for remediation.

Over the past decade, DOE’s progress towards cleanup has been stymied in part by a lack of investment in basic science that is foundational to innovation and new technology development. During this decade, amazing progress has been made in both experimental and computational tools that have been applied to many energy problems such as catalysis, bioenergy, solar energy, etc. Our abilities to observe, model, and exploit chemical phenomena at the atomic level along with our understanding of the translation of molecular phenomena to macroscopic behavior and properties have advanced tremendously; however, remediation of DOE’s legacy waste problems has not yet benefited from these advances because of the lack investment in basic science for environmental cleanup.

Advances in science and technology can provide the foundation for completing the cleanup more swiftly, inexpensively, safely, and effectively. The lack of investment in research and technology development by DOE’s Office of Environmental Management (EM) was noted in a report by a task force to the Secretary of Energy’s Advisory Board (SEAB 2014). Among several recommendations, the report suggested a workshop be convened to develop a strategic plan for a “fundamental research program focused on developing new knowledge and capabilities that bear on the EM challenges.” This report summarizes the research directions identified at a workshop on Basic Research Needs for Environmental Management. This workshop, held July 8-11, 2015, was sponsored by three Office of Science offices: Basic Energy Sciences, Biological and Environmental Research, and Advanced Scientific Computing Research. The workshop participants included 65 scientists and engineers from universities, industry, and national laboratories, along with observers from the DOE Offices of Science, EM, Nuclear Energy, and Legacy Management.

As a result of the discussions at the workshop, participants articulated two Grand Challenges for science associated with EM cleanup needs. They are as follows:

Interrogation of Inaccessible Environments over Extremes of Time and Space

Whether the contamination problem involves highly radioactive materials in underground waste tanks or large volumes of contaminated soils and groundwaters beneath the Earth’s surface, characterizing the problem is often stymied by an inability to safely and cost effectively interrogate the system. Sensors and imaging capabilities that can operate in the extreme environments typical of EM’s remaining cleanup challenges do not exist. Alternatively, large amounts of data can sometimes be obtained about a system, but appropriate data analytics tools are lacking to enable effective and efficient use of all the information for performance regression or prediction. Research into new approaches for remote and in situ sensing, and new algorithms for data analytics are critically needed. Depending on the cleanup problem, these new approaches must span temporal and spatial scales—from seconds to millennia, from atoms to kilometers.

Understanding and Exploiting Interfacial Phenomena in Extreme Environments

While many of EM’s remaining cleanup problems involve unprecedented extremes in complexity, an additional layer is provided by the numerous contaminant forms and their partitioning across interfaces in these wastes, including liquid-liquid, liquid-solid, and others. For example, the wastes in the high-level radioactive waste tanks can have consistencies of paste, gels, or Newtonian slurries, where water behaves more like a solute than a solvent. Unexpected chemical forms of the contaminants and radionuclides partition to unusual solids, colloids, and other phases in the tank wastes, complicating their efficient separation. Mastery of the chemistry controlling contaminant speciation and its behavior at the solid-liquid and liquid-liquid interfaces in the presence of large quantities of ionizing radiation is needed to develop improved waste treatment approaches and enhance the operating efficiencies of treatment facilities. These same interfacial processes, if understood, can be exploited to develop entirely new approaches for effective separations technologies, both for tank waste processing and subsurface remediation.

Based on the findings of the technical panels, six Priority Research Directions (PRDs) were identified as the most urgent scientific areas that need to be addressed to enable EM to meet its mission goals. All of these PRDs are also embodied in the two Grand Challenges. Further, these six PRDs are relevant to all aspects of EM waste issues, including tank wastes, waste forms, and subsurface contamination. These PRDs include the following:

Elucidating and exploiting complex speciation and reactivity far from equilibrium
Understanding and controlling chemical and physical processes at interfaces
Harnessing physical and chemical processes to revolutionize separations
Mechanisms of materials degradation in harsh environments
Mastering hierarchical structures to tailor waste forms
Predictive understanding of subsurface system behavior and response to perturbations.

Two recurring themes emerged during the course of the workshop that cut across all of the PRDs. These crosscutting topics give rise to Transformative Research Capabilities. The first such capability, Multidimensional characterization of extreme, dynamic, and inaccessible environments, centers on the need for obtaining detailed chemical and physical information on EM wastes in waste tanks and during waste processing, in wastes forms, and in the environment. New approaches are needed to characterize and monitor these highly hazardous and/or inaccessible materials in their natural environment, either using in situ techniques or remote monitoring. These approaches are particularly suited for studying changes in the wastes over time and distances, for example. Such in situ and remote techniques are also critical for monitoring the effectiveness of waste processes, subsurface transport, and long-term waste form stability. However, far more detailed information will be needed to obtain fundamental insight into materials structure and molecular-level chemical and physical processes required for many of the PRDs. For these studies, samples must be retrieved and studied ex situ, but the hazardous nature of these samples requires special handling. Recent advances in nanoscience have catalyzed the development of high-sensitivity characterization tools—many of which are available at DOE user facilities, including radiological user facilities—and the means of handling ultrasmall samples, including micro- and nanofluidics and nanofabrication tools. These advances open the door to obtaining unprecedented information that is crucial to formulating concepts for new technologies to complete EM’s mission.

The sheer magnitude of the data needed to fully understand the complexity of EM wastes is daunting, but it is just the beginning. Additional data will need to be gathered to both monitor and predict changes—in tank wastes, during processing, in waste forms and in the subsurface over broad time and spatial scales. Therefore, the second Transformative Research Capability, Integrated simulation and data-enabled discovery, identified the need to develop curated databases and link experiments and theory through big-deep data methodologies. These state-of-the-art capabilities will be enabled by high-performance computing resources available at DOE user facilities.

The foundational knowledge to support innovation for EM cannot wait as the tank wastes continue to deteriorate and result in environmental, health, and safety issues. As clearly stated in the 2014 Secretary of Energy Advisory Board report, completion of EM’s remaining responsibilities will simply not be possible without significant innovation and that innovation can be derived from use-inspired fundamental research as described in this report. The breakthroughs that will evolve from this investment in basic science will reduce the overall risk and financial burden of cleanup while also increasing the probability of success. The time is now ripe to proceed with the basic science in support of more effective solutions for environmental management. The knowledge gleaned from this basic research will also have broad applicability to many other areas central to DOE’s mission, including separations methods for critical materials recovery and isotope production, robust materials for advanced reactor and steam turbine designs, and new capabilities for examining subsurface transport relevant to the water/energy nexus.

Challenges at the Frontiers of Matter and Energy: Transformative Opportunities for Discovery Science

JPG
Report

FIVE TRANSFORMATIVE OPPORTUNITIES FOR DISCOVERY SCIENCE
As a result of this effort, it has become clear that the progress made to date on the five Grand Challenges has created a springboard for seizing five new Transformative Opportunities that have the potential to further transform key technologies involving matter and energy. These five new Transformative Opportunities and the evidence supporting them are discussed in this new report, “Challenges at the Frontiers of Matter and Energy: Transformative Opportunities for Discovery Science.”
Mastering Hierarchical Architectures and Beyond-Equilibrium Matter
Complex materials and chemical processes transmute matter and energy, for example from CO2 and water to chemical fuel in photosynthesis, from visible light to electricity in solar cells and from electricity to light in light emitting diodes (LEDs) Such functionality requires complex assemblies of heterogeneous materials in hierarchical architectures that display time-dependent away-from-equilibrium behaviors. Much of the foundation of our understanding of such transformations however, is based on monolithic single- phase materials operating at or near thermodynamic equilibrium. The emergent functionalities enabling next-generation disruptive energy technologies require mastering the design, synthesis, and control of complex hierarchical materials employing dynamic far-from-equilibrium behavior. A key guide in this pursuit is nature, for biological systems prove the power of hierarchical assembly and far- from-equilibrium behavior. The challenges here are many: a description of the functionality of hierarchical assemblies in terms of their constituent parts, a blueprint of atomic and molecular positions for each constituent part, and a synthesis strategy for (a) placing the atoms and molecules in the proper positions for the component parts and (b) arranging the component parts into the required hierarchical structure. Targeted functionality will open the door to significant advances in the harvesting, transforming (e.g., reducing CO2, splitting water, and fixing nitrogen), storing, and use of energy to create new materials, manufacturing processes, and technologies—the lifeblood of human societies and economic growth.
Beyond Ideal Materials and Systems: Understanding the Critical Roles of Heterogeneity, Interfaces, and Disorder
Real materials, both natural ones and those we engineer, are usually a complex mixture of compositional and structural heterogeneities, interfaces, and disorder across all spatial and temporal scales. It is the fluctuations and disorderly states of these heterogeneities and interfaces that often determine the system’s properties and functionality. Much of our fundamental scientific knowledge is based on “ideal” systems, meaning materials that are observed in “frozen” states or represented by spatially or temporally averaged states. Too often, this approach has yielded overly simplistic models that hide important nuances and do not capture the complex behaviors of materials under realistic conditions. These behaviors drive vital chemical transformations such as catalysis, which initiates most industrial manufacturing processes, and friction and corrosion, the parasitic effects of which cost the U.S. economy billions of dollars annually. Expanding our scientific knowledge from the relative simplicity of ideal, perfectly ordered, or structurally averaged materials to the true complexity of real-world heterogeneities, interfaces, and disorder should enable us to realize enormous benefits in the materials and chemical sciences, which translates to the energy sciences, including solar and nuclear power, hydraulic fracturing, power conversion, airframes, and batteries.
Harnessing Coherence in Light and Matter
Quantum coherence in light and matter is a measure of the extent to which a wave field vibrates in unison with itself at neighboring points in space and time. Although this phenomenon is expressed at the atomic and electronic scales, it can dominate the macroscopic properties of materials and chemical reactions such as superconductivity and efficient photosynthesis. In recent years, enormous progress has been made in recognizing, manipulating, and exploiting quantum coherence. This progress has already elucidated the role that symmetry plays in protecting coherence in key materials, taught us how to use light to manipulate atoms and molecules, and provided us with increasingly sophisticated techniques for controlling and probing the charges and spins of quantum coherent systems. With the arrival of new sources of coherent light and electron beams, thanks in large part to investments by the U.S. Department of Energy’s Office of Basic Energy Sciences (BES), there is now an opportunity to engineer coherence in heterostructures that incorporate multiple types of materials and to control complex, multistep chemical transformations. This approach will pave the way for quantum information processing and next-generation photovoltaic cells and sensors.
Revolutionary Advances in Models, Mathematics, Algorithms, Data, and Computing
Science today is benefiting from a convergence of theoretical, mathematical, computational, and experimental capabilities that put us on the brink of greatly accelerating our ability to predict, synthesize, and control new materials and chemical processes, and to understand the complexities of matter across a range of scales. Imagine being able to chart a path through a vast sea of possible new materials to find a select few with desired properties. Instead of the time-honored forward approach, in which materials with desired properties are found through either trial-and-error experiments or lucky accidents, we have the opportunity to inversely design and create new materials that possess the properties we desire. The traditional approach has allowed us to make only a tiny fraction of all the materials that are theoretically possible. The inverse design approach, through the harmonious convergence of theoretical, mathematical, computational, and experimental capabilities, could usher in a virtual cornucopia of new materials with functionalities far beyond what nature can provide. Similarly, enhanced mathematical and computational capabilities significantly enhance our ability to extract physical and chemical insights from vastly larger data streams gathered during multimodal and multidimensional experiments using advanced characterization facilities.
Exploiting Transformative Advances in Imaging Capabilities across Multiple Scales
Historically, improvements in imaging capabilities have always resulted in improved understanding of scientific phenomena. A prime challenge today is finding ways to reconstruct raw data, obtained by probing and mapping matter across multiple scales, into analyzable images. BES investments in new and improved imaging facilities, most notably synchrotron x-ray sources, free-electron lasers, electron microscopes, and neutron sources, have greatly advanced our powers of observation, as have substantial improvements in laboratory- scale technologies. Furthermore, BES is now planning or actively discussing exciting new capabilities. Taken together, these advances in imaging capabilities provide an opportunity to expand our ability to observe and study matter from the 3D spatial perspectives of today to true “4D” spatially and temporally resolved maps of dynamics that allow quantitative predictions of time-dependent material properties and chemical processes. The knowledge gained will impact data storage, catalyst design, drug delivery, structural materials, and medical implants, to name just a few key technologies.
ENABLING SUCCESS
Seizing each of these five Transformative Opportunities, as well as accelerating further progress on Grand Challenge research, will require specific, targeted investments from BES in the areas of synthesis, meaning the ability to make the materials and architectures that are envisioned; instrumentation and tools, a category that includes theory and computation; and human capital, the most important asset for advancing the Grand Challenges and Transformative Opportunities. While “Challenges at the Frontiers of Matter and Energy: Transformative Opportunities for Discovery Science” could be viewed as a sequel to the original Grand Challenges report, it breaks much new ground in its assessment of the scientific landscape today versus the scientific landscape just a few years ago. In the original Grand Challenges report, it was noted that if the five Grand Challenges were met, our ability to direct matter and energy would be measured only by the limits of human imagination. This new report shows that, prodded by those challenges, the scientific community is positioned today to seize new opportunities whose impacts promise to be transformative for science and society, as well as dramatically accelerate progress in the pursuit of the original Grand Challenges.

Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda

JPG
Report

From beneath the surface of the earth, we currently obtain about 80-percent of the energy our nation consumes each year. In the future we have the potential to generate billions of watts of electrical power from clean, green, geothermal energy sources. Our planet’s subsurface can also serve as a reservoir for storing energy produced from intermittent sources such as wind and solar, and it could provide safe, long-term storage of excess carbon dioxide, energy waste products and other hazardous materials. However, it is impossible to underestimate the complexities of the subsurface world. These complexities challenge our ability to acquire the scientific knowledge needed for the efficient and safe exploitation of its resources.

To more effectively harness subsurface resources while mitigating the impacts of developing and using these resources, the U.S. Department of Energy established SubTER – the Subsurface Technology and Engineering RD&D Crosscut team. This DOE multi-office team engaged scientists and engineers from the national laboratories to assess and make recommendations for improving energy-related subsurface engineering. The SubTER team produced a plan with the overall objective of “adaptive control of subsurface fractures and fluid flow.”This plan revolved around four core technological pillars—Intelligent Wellbore Systems that sustain the integrity of the wellbore environment; Subsurface Stress and Induced Seismicity programs that guide and optimize sustainable energy strategies while reducing the risks associated with subsurface injections; Permeability Manipulation studies that improve methods of enhancing, impeding and eliminating fluid flow; and New Subsurface Signals that transform our ability to see into and characterize subsurface systems.

The SubTER team developed an extensive R&D plan for advancing technologies within these four core pillars and also identified several areas where new technologies would require additional basic research. In response, the Office of Science, through its Office of Basic Energy Science (BES), convened a roundtable consisting of 15 national lab, university and industry geoscience experts to brainstorm basic research areas that underpin the SubTER goals but are currently
underrepresented in the BES research portfolio. Held in Germantown, Maryland on May 22, 2015, the round-table participants developed a basic research agenda that is detailed in this report.

Highlights include the following:

A grand challenge calling for advanced imaging of stress and geological processes to help understand how stresses and chemical substances are distributed in the subsurface—knowledge that is critical to all aspects of subsurface engineering;
A priority research direction aimed at achieving control of fluid flow through fractured media;
A priority research direction aimed at better understanding how mechanical and geochemical perturbations to subsurface rock systems are coupled through fluid and mineral interactions;
A priority research direction aimed at studying the structure, permeability, reactivity and other properties of nanoporous rocks, like shale, which have become critical energy materials and exhibit important hallmarks of mesoscale materials;
A cross-cutting theme that would accelerate development of advanced computational methods to describe heterogeneous time-dependent geologic systems that could, among other potential benefits, provide new and vastly improved models of hydraulic fracturing and its environmental impacts;
A cross-cutting theme that would lead to the creation of “geo-architected materials” with controlled repeatable heterogeneity and structure that can be tested under a variety of thermal, hydraulic, chemical and mechanical conditions relevant to subsurface systems;
A cross-cutting theme calling for new laboratory studies on both natural and geo-architected subsurface materials that deploy advanced high-resolution 3D imaging and chemical analysis methods to determine the ;rates and mechanisms of fluid-rock processes, and to test predictive models of such phenomena.

Many of the key energy challenges of the future demand a greater understanding of the subsurface world in all of its complexity. This greater under- standing will improve the ability to control and manipulate the subsurface world in ways that will benefit both the economy and the environment. This report provides specific basic research pathways to address some of the most fundamental issues of energy-related subsurface engineering.

X-ray Optics for BES Light Source Facilities

JPG
Report

Future of Electron Scattering and Diffraction

The ability to correlate the atomic- and nanoscale-structure of condensed matter with physical properties (e.g., mechanical, electrical, catalytic, and optical) and functionality forms the core of many disciplines. Directing and controlling materials at the quantum-, atomic-, and molecular-levels creates enormous challenges and opportunities across a wide spectrum of critical technologies, including those involving the generation and use of energy. The workshop identified next generation electron scattering and diffraction instruments that are uniquely positioned to address these grand challenges. The workshop participants identified four key areas where the next generation of such instrumentation would have major impact:

A – Multidimensional Visualization of Real Materials
B – Atomic-scale Molecular Processes
C – Photonic Control of Emergence in Quantum Materials
D – Evolving Interfaces, Nucleation, and Mass Transport

Real materials are comprised of complex three-dimensional arrangements of atoms and defects that directly determine their potential for energy applications. Understanding real materials requires new capabilities for three-dimensional atomic scale tomography and spectroscopy of atomic and electronic structures with unprecedented sensitivity, and with simultaneous spatial and energy resolution. Many molecules are able to selectively and efficiently convert sunlight into other forms of energy, like heat and electric current, or store it in altered chemical bonds. Understanding and controlling such process at the atomic scale require unprecedented time resolution. One of the grand challenges in condensed matter physics is to understand, and ultimately control, emergent phenomena in novel quantum materials that necessitate developing a new generation of instruments that probe the interplay among spin, charge, orbital, and lattice degrees of freedom with intrinsic time- and length-scale resolutions. Molecules and soft matter require imaging and spectroscopy with high spatial resolution without damaging their structure. The strong interaction of electrons with matter allows high-energy electron pulses to gather structural information before a sample is damaged.

Imaging, diffraction, and spectroscopy are the fundamental capabilities of electron-scattering instruments. The DOE BES-funded TEAM (Transmission Electron Aberration-corrected Microscope) project achieved unprecedented sub-atomic spatial resolution in imaging through aberration-corrected transmission electron microscopy. To further advance electron scattering techniques that directly enable groundbreaking science, instrumentation must advance beyond traditional two-dimensional imaging. Advances in temporal resolution, recording the full phase and energy spaces, and improved spatial resolution constitute a new frontier in electron microscopy, and will directly address the BES Grand Challenges, such as to “control the emergent properties that arise from the complex correlations of atomic and electronic constituents” and the “hidden states” “very far away from equilibrium”. Ultrafast methods, such as the pump-probe approach, enable pathways toward understanding, and ultimately controlling, the chemical dynamics of molecular systems and the evolution of complexity in mesoscale and nanoscale systems. Central to understanding how to synthesize and exploit functional materials is having the ability to apply external stimuli (such as heat, light, a reactive flux, and an electrical bias) and to observe the resulting dynamic process in situ and in operando, and under the appropriate environment (e.g., not limited to UHV conditions).

To enable revolutionary advances in electron scattering and science, the participants of the workshop recommended three major new instrumental developments:

A. Atomic-Resolution Multi-Dimensional Transmission Electron Microscope: This instrument would provide quantitative information over the entire real space, momentum space, and energy space for visualizing dopants, interstitials, and light elements; for imaging localized vibrational modes and the motion of charged particles and vacancies; for correlating lattice, spin, orbital, and charge; and for determining the structure and molecular chemistry of organic and soft matter. The instrument will be uniquely suited to answer fundamental questions in condensed matter physics that require understanding the physical and electronic structure at the atomic scale. Key developments include stable cryogenic capabilities that will allow access to emergent electronic phases, as well as hard/soft interfaces and radiation- sensitive materials.

B. Ultrafast Electron Diffraction and Microscopy Instrument: This instrument would be capable of nano-diffraction with 10 fs temporal resolution in stroboscopic mode, and better than 100 fs temporal resolution in single shot mode. The instrument would also achieve single- shot real-space imaging with a spatial/temporal resolution of 10 nm/10 ps, representing a thousand fold improvement over current microscopes. Such a capability would be complementary to x-ray free electron lasers due to the difference in the nature of electron and x-ray scattering, enabling space-time mapping of lattice vibrations and energy transport, facilitating the understanding of molecular dynamics of chemical reactions, the photonic control of emergence in quantum materials, and the dynamics of mesoscopic materials.

C. Lab-In-Gap Dynamic Microscope: This instrument would enable quantitative measurements of materials structure, composition, and bonding evolution in technologically relevant environments, including liquids, gases and plasmas, thereby assuring the understanding of structure function relationship at the atomic scale with up to nanosecond temporal resolution. This instrument would employ a versatile, modular sample stage and holder geometry to allow the multi-modal (e.g., optical, thermal, mechanical, electrical, and electrochemical) probing of materials’ functionality in situ and in operando. The electron optics encompasses a pole piece that can accommodate the new stage, differential pumping, detectors, aberration correctors, and other electron optical elements for measurement of materials dynamics.

To realize the proposed instruments in a timely fashion, BES should aggressively support research and development of complementary and enabling instruments, including new electron sources, advanced electron optics, new tunable specimen pumps and sample stages, and new detectors. The proposed instruments would have transformative impact on physics, chemistry, materials science, engineering

JPG
Report
Hi-Res

X-ray Optics for BES Light Source Facilities

Each new generation of synchrotron radiation sources has delivered an increase in average brightness 2 to 3 orders of magnitude over the previous generation. The next evolution toward diffraction-limited storage rings will deliver another 3 orders of magnitude increase. For ultrafast experiments, free electron lasers (FELs) deliver 10 orders of magnitude higher peak brightness than storage rings. Our ability to utilize these ultrabright sources, however, is limited by our ability to focus, monochromate, and manipulate these beams with X-ray optics. X-ray optics technology unfortunately lags behind source technology and limits our ability to maximally utilize even today’s X-ray sources. With ever more powerful X-ray sources on the horizon, a new generation of X-ray optics must be developed that will allow us to fully utilize these beams of unprecedented brightness.

The increasing brightness of X-ray sources will enable a new generation of measurements that could have revolutionary impact across a broad area of science, if optical systems necessary for transporting and analyzing X-rays can be perfected. The high coherent flux will facilitate new science utilizing techniques in imaging, dynamics, and ultrahigh-resolution spectroscopy. For example, zone-plate-based hard X-ray microscopes are presently used to look deeply into materials, but today’s resolution and contrast are restricted by limitations of the current lithography used to manufacture nanodiffractive optics. The large penetration length, combined in principle with very high spatial resolution, is an ideal probe of hierarchically ordered mesoscale materials, if zone-plate focusing systems can be improved. Resonant inelastic X-ray scattering (RIXS) probes a wide range of excitations in materials, from charge-transfer processes to the very soft excitations that cause the collective phenomena in correlated electronic systems. However, although RIXS can probe high-energy excitations, the most exciting and potentially revolutionary science involves soft excitations such as magnons and phonons; in general, these are well below the resolution that can be probed by today’s optical systems. The study of these low-energy excitations will only move forward if advances are made in high-resolution gratings for the soft X-ray energy region, and higher-resolution crystal analyzers for the hard X-ray region. In almost all the forefront areas of X-ray science today, the main limitation is our ability to focus, monochromate, and manipulate X-rays at the level required for these advanced measurements.

To address these issues, the U.S. Department of Energy (DOE) Office of Basic Energy Sciences (BES) sponsored a workshop, X-ray Optics for BES Light Source Facilities, which was held March 27–29, 2013, near Washington, D.C. The workshop addressed a wide range of technical and organizational issues. Eleven working groups were formed in advance of the meeting and sought over several months to define the most pressing problems and emerging opportunities and to propose the best routes forward for a focused R&D program to solve these problems. The workshop participants identified eight principal research directions (PRDs), as follows:

Development of advanced grating lithography and manufacturing for high-energy resolution techniques such as soft X-ray inelastic scattering.
Development of higher-precision mirrors for brightness preservation through the use of advanced metrology in manufacturing, improvements in manufacturing techniques, and in mechanical mounting and cooling.
Development of higher-accuracy optical metrology that can be used in manufacturing, verification, and testing of optomechanical systems, as well as at wavelength metrology that can be used for quantification of individual optics and alignment and testing of beamlines.
Development of an integrated optical modeling and design framework that is designed and maintained specifically for X-ray optics.
Development of nanolithographic techniques for improved spatial resolution and efficiency of zone plates.
Development of large, perfect single crystals of materials other than silicon for use as beam splitters, seeding monochromators, and high-resolution analyzers.
Development of improved thin-film deposition methods for fabrication of multilayer Laue lenses and high-spectral-resolution multilayer gratings.
Development of supports, actuator technologies, algorithms, and controls to provide fully integrated and robust adaptive X-ray optic systems.
Development of fabrication processes for refractive lenses in materials other than silicon.

The workshop participants also addressed two important nontechnical areas: our relationship with industry and organization of optics within the light source facilities. Optimization of activities within these two areas could have an important effect on the effectiveness and efficiency of our overall endeavor. These are crosscutting managerial issues that we identified as areas that needed further in-depth study, but they need to be coordinated above the individual facilities.

Finally, an issue that cuts across many of the optics improvements listed above is routine access to beamlines that ideally are fully dedicated to optics research and/or development. The success of the BES X-ray user facilities in serving a rapidly increasing user community has led to a squeezing of beam time for vital instrumentation activities. Dedicated development beamlines could be shared with other R&D activities, such as detector programs and novel instrument development.

In summary, to meet the challenges of providing the highest-quality X-ray beams for users and to fully utilize the high-brightness sources of today and those that are on the horizon, it will be critical to make strategic investments in X-ray optics R&D. This report can provide guidance and direction for effective use of investments in the field of X-ray optics and potential approaches to develop a better-coordinated program of X-ray optics development within the suite of BES synchrotron radiation facilities. Due to the importance and complexity of the field, the need for tight coordination between BES light source facilities and with industry, as well as the rapid evolution of light source capabilities the workshop participants recommend holding similar workshops at least biannually.

JPG
Report
Report

Neutron and X-ray Detectors

The Basic Energy Sciences (BES) X-ray and neutron user facilities attract more than 12,000 researchers each year to perform cutting-edge science at these state-of-the-art sources. While impressive breakthroughs in X-ray and neutron sources give us the powerful illumination needed to peer into the nano- to mesoscale world, a stumbling block continues to be the distinct lag in detector development, which is slowing progress toward data collection and analysis. Urgently needed detector improvements would reveal chemical composition and bonding in 3-D and in real time, allow researchers to watch “movies” of essential life processes as they happen, and make much more efficient use of every X-ray and neutron produced by the source

The immense scientific potential that will come from better detectors has triggered worldwide activity in this area. Europe in particular has made impressive strides, outpacing the United States on several fronts. Maintaining a vital U.S. leadership in this key research endeavor will require targeted investments in detector R&D and infrastructure.

To clarify the gap between detector development and source advances, and to identify opportunities to maximize the scientific impact of BES user facilities, a workshop on Neutron and X-ray Detectors was held August 1-3, 2012, in Gaithersburg, Maryland. Participants from universities, national laboratories, and commercial organizations from the United States and around the globe participated in plenary sessions, breakout groups, and joint open-discussion summary sessions.

Sources have become immensely more powerful and are now brighter (more particles focused onto the sample per second) and more precise (higher spatial, spectral, and temporal resolution). To fully utilize these source advances, detectors must become faster, more efficient, and more discriminating. In supporting the mission of today’s cutting-edge neutron and X-ray sources, the workshop identified six detector research challenges (and two computing hurdles that result from the corresponding increase in data volume) for the detector community to overcome in order to realize the full potential of BES neutron and X-ray facilities.

Resolving these detector impediments will improve scientific productivity both by enabling new types of experiments, which will expand the scientific breadth at the X-ray and neutron facilities, and by potentially reducing the beam time required for a given experiment. These research priorities are summarized in the table below. Note that multiple, simultaneous detector improvements are often required to take full advantage of brighter sources.

High-efficiency hard X-ray sensors: The fraction of incident particles that are actually detected defines detector efficiency. Silicon, the most common direct-detection X-ray sensor material, is (for typical sensor thicknesses) 100% efficient at 8 keV, 25%efficient at 20 keV, and only 3% efficient at 50 keV. Other materials are needed for hard X-rays.

Replacement for ³He for neutron detectors: ³He has long been the neutron detection medium of choice because of its high cross section over a wide neutron energy range for the reaction ³He + n —> ³H + 1H + 0.764 MeV. ³He stockpiles are rapidly dwindling, and what is available can be had only at prohibitively high prices. Doped scintillators hold promise as ways to capture neutrons and convert them into light, although work is needed on brighter, more efficient scintillator solutions. Neutron detectors also require advances in speed and resolution.

Fast-framing X-ray detectors: Today’s brighter X-ray sources make time-resolved studies possible. For example, hybrid X-ray pixel detectors, initially developed for particle physics, are becoming fairly mature X-ray detectors, with considerable development in Europe. To truly enable time-resolved studies, higher frame rates and dynamic range are required, and smaller pixel sizes are desirable.

High-speed spectroscopic X-ray detectors: Improvements in the readout speed and energy resolution of X-ray detectors are essential to enable chemically sensitive microscopies. Advances would make it possible to take images with simultaneous spatial and chemical information.

Very high-energy-resolution X-ray detectors: The energy resolution of semiconductor detectors, while suitable for a wide range of applications, is far less than what can be achieved with X-ray optics. A direct detector that could rival the energy resolution of optics could dramatically improve the efficiency of a multitude of experiments, as experiments are often repeated at a number of different energies. Very high-energy-resolution detectors could make these experiments parallel, rather than serial.

Low-background, high-spatial-resolution neutron detectors: Low-background detectors would significantly improve experiments that probe excitations (phonons, spin excitations, rotation, and diffusion in polymers and molecular substances, etc.) in condensed matter. Improved spatial resolution would greatly benefit radiography, tomography, phase-contrast imaging, and holography.

Improved acquisition and visualization tools: In the past, with the limited variety of slow detectors, it was straightforward to visualize data as it was being acquired (and adjust experimental conditions accordingly) to create a compact data set that the user could easily transport. As detector complexity and data rates explode, this becomes much more challenging. Three goals were identified as important for coping with the growing data volume from high-speed detectors:

Facilitate better algorithm development. In particular, algorithms that can minimize the quantity of data stored.
Improve community-driven mechanisms to reduce data protocols and enhance quantitative, interactive visualization tools.
Develop and distribute community-developed, detector-specific simulation tools.
Aim for parallelization to take advantage of high-performance analysis platforms.

Improved analysis work flows: Standardize the format of metadata that accompanies detector data and describes the experimental setup and conditions. Develop a standardized user interface and software framework for analysis and data management.

The diversity of detector improvements required is necessarily as broad as the range of scientific experimentation at BES facilities. This workshop identified a variety of avenues by which detector R&D can enable enhanced science at BES facilities. The Research Directions listed above will be addressed by focused R&D and detector engineering, both of which require specialized infrastructure and skills. While U.S. leadership in neutron and X-ray detectors lags behind other countries in several areas, significant talent exists across the complex. A forum of technical experts, facilities management, and BES could be a venue to provide further definition.

JPG
Report
Hi-res

From Quanta to the Continuum: Opportunities for Mesoscale Science
We are at a time of unprecedented challenge and opportunity. Our economy is in need of a jump start, and our supply of clean energy needs to dramatically increase. Innovation through basic research is a key means for addressing both of these challenges. The great scientific advances of the last decade and more, especially at the nanoscale, are ripe for exploitation. Seizing this key opportunity requires mastering the mesoscale, where classical, quantum, and nanoscale science meet. It has become clear that—in many important areas—the functionality that is critical to macroscopic behavior begins to manifest itself not at the atomic or nanoscale but at the mesoscale, where defects, interfaces, and non-equilibrium structures are the norm. With our recently acquired knowledge of the rules of nature that govern the atomic and nanoscales, we are well positioned to unravel and control the complexity that determines functionality at the mesoscale. The reward for breakthroughs in our understanding at the mesoscale is the emergence of previously unrealized functionality. The present report explores the opportunity and defines the research agenda for mesoscale science—discovering, understanding, and controlling interactions among disparate systems and phenomena to reach the full potential of materials complexity and functionality. The ability to predict and control mesoscale phenomena and architectures is essential if atomic and molecular knowledge is to blossom into a next generation of technology opportunities, societal benefits, and scientific advances.

Imagine the ability to manufacture at the mesoscale: that is, the directed assembly of mesoscale structures that possess unique functionality that yields faster, cheaper, higher performing, and longer lasting products, as well as products that have functionality that we have not yet imagined.
Imagine the realization of biologically inspired complexity and functionality with inorganic earth-abundant materials to transform energy conversion, transmission, and storage.
Imagine the transformation from top-down design of materials and systems with macroscopic building blocks to bottom-up design with nanoscale functional units producing next-generation technological innovation.
This is the promise of mesoscale science.

Mesoscale science and technology opportunities build on the enormous foundation of nanoscience that the scientific community has created over the last decade and continues to create. New features arise naturally in the transition to the mesoscale, including the emergence of collective behavior; the interaction of disparate electronic, mechanical, magnetic, and chemical phenomena; the appearance of defects, interfaces and statistical variation; and the self assembly of functional composite systems. The mesoscale represents a discovery laboratory for finding new science, a self-assembly foundry for creating new functional systems, and a design engine for new technologies.

The last half-century and especially the last decade have witnessed a remarkable drive to ever smaller scales, exposing the atomic, molecular, and nanoscale structures that anchor the macroscopic materials and phenomena we deal with every day. Given this knowledge and capability, we are now starting the climb up from the atomic and nanoscale to the greater complexity and wider horizons of the mesoscale. The constructionist path up from atomic and nanoscale to mesoscale holds a different kind of promise than the reductionist path down: it allows us to re-arrange the nanoscale building blocks into new combinations, exploit the dynamics and kinetics of these new coupled interactions, and create qualitatively different mesoscale architectures and phenomena leading to new functionality and ultimately new technology. The reductionist journey to smaller length and time scales gave us sophisticated observational tools and intellectual understanding that we can now apply with great advantage to the wide opportunity of mesoscale science following a bottom-up approach.
Realizing the mesoscale opportunity requires advances not only in our knowledge but also in our ability to observe, characterize, simulate, and ultimately control matter. Mastering mesoscale materials and phenomena requires the seamless integration of theory, modeling, and simulation with synthesis and characterization. The inherent complexity of mesoscale phenomena, often including many nanoscale structural or functional units, requires theory and simulation spanning multiple space and time scales. In mesoscale architectures the positions of individual atoms are often no longer relevant, requiring new simulation approaches beyond density functional theory and molecular dynamics that are so successful at atomic scales. New organizing principles that describe emergent mesoscale phenomena arising from many coupled and competing degrees of freedom wait to be discovered and applied. Measurements that are dynamic, in situ, and multimodal are needed to capture the sequential phenomena of composite mesoscale materials. Finally, the ability to design and realize the complex materials we imagine will require qualitative advances in how we synthesize and fabricate materials and how we manage their metastability and degradation over time. We must move from serendipitous to directed discovery, and we must master the art of assembling structural and functional nanoscale units into larger architectures that create a higher level of complex functional systems.
While the challenge of discovering, controlling, and manipulating complex mesoscale architectures and phenomena to realize new functionality is immense, success in the pursuit of these research directions will have outcomes with the potential to transform society. The body of this report outlines the need, the opportunities, the challenges, and the benefits of mastering mesoscale science.

JPG
Report

Data and Communications in Basic Energy Sciences: Creating a Pathway for Scientific Discovery

This report is based on the Department of Energy (DOE) Workshop on “Data and Communications in Basic Energy Sciences: Creating a Pathway for Scientific Discovery” that was held at the Bethesda Marriott in Maryland on October 24-25, 2011. The workshop brought together leading researchers from the Basic Energy Sciences (BES) facilities and Advanced Scientific Computing Research (ASCR). The workshop was co-sponsored by these two Offices to identify opportunities and needs for data analysis, ownership, storage, mining, provenance and data transfer at light sources, neutron sources, microscopy centers and other facilities.

Their charge was to identify current and anticipated issues in the acquisition, analysis, communication and storage of experimental data that could impact the progress of scientific discovery, ascertain what knowledge, methods and tools are needed to mitigate present and projected shortcomings and to create the foundation for information exchanges and collaboration between ASCR and BES supported researchers and facilities.

The workshop was organized in the context of the impending data tsunami that will be produced by DOE’s BES facilities. Current facilities, like SLAC National Accelerator Laboratory’s Linac Coherent Light Source, can produce up to 18 terabytes (TB) per day, while upgraded detectors at Lawrence Berkeley National Laboratory’s Advanced Light Source will generate ~10TB per hour. The expectation is that these rates will increase by over an order of magnitude in the coming decade. The urgency to develop new strategies and methods in order to stay ahead of this deluge and extract the most science from these facilities was recognized by all. The four focus areas addressed in this workshop were:

Workflow Management - Experiment to Science: Identifying and managing the data path from experiment to publication.
Theory and Algorithms: Recognizing the need for new tools for computation at scale, supporting large data sets and realistic theoretical models.
Visualization and Analysis: Supporting near-real-time feedback for experiment optimization and new ways to extract and communicate critical information from large data sets.
Data Processing and Management: Outlining needs in computational and communication approaches and infrastructure needed to handle unprecedented data volume and information content.

It should be noted that almost all participants recognized that there were unlikely to be any turn-key solutions available due to the unique, diverse nature of the BES community, where research at adjacent beamlines at a given light source facility often span everything from biology to materials science to chemistry using scattering, imaging and/or spectroscopy. However, it was also noted that advances supported by other programs in data research, methodologies, and tool development could be implemented on reasonable time scales with modest effort. Adapting available standard file formats, robust workflows, and in-situ analysis tools for user facility needs could pay long-term dividends.

Workshop participants assessed current requirements as well as future challenges and made the following recommendations in order to achieve the ultimate goal of enabling transformative science in current and future BES facilities:

Theory and analysis components should be integrated seamlessly within experimental workflow.
Develop new algorithms for data analysis based on common data formats and toolsets.

Move analysis closer to experiment.
Move the analysis closer to the experiment to enable real-time (in-situ) streaming capabilities, live visualization of the experiment and an increase of the overall experimental efficiency.

Match data management access and capabilities with advancements in detectors and sources.
Remove bottlenecks, provide interoperability across different facilities/beamlines and apply forefront mathematical techniques to more efficiently extract science from the experiments.

This workshop report examines and reviews the status of several BES facilities and highlights the successes and shortcomings of the current data and communication pathways for scientific discovery. It then ascertains what methods and tools are needed to mitigate present and projected data bottlenecks to science over the next 10 years. The goal of this report is to create the foundation for information exchanges and collaborations among ASCR and BES supported researchers, the BES scientific user facilities, and ASCR computing and networking facilities.

To jumpstart these activities, there was a strong desire to see a joint effort between ASCR and BES along the lines of the highly successful Scientific Discovery through Advanced Computing (SciDAC) program in which integrated teams of engineers, scientists and computer scientists were engaged to tackle a complete end-to-end workflow solution at one or more beamlines, to ascertain what challenges will need to be addressed in order to handle future increases in data

JPG
Report

Research Needs and Impacts in Predictive Simulation for Internal Combustion Engines (PreSICE)

This report is based on a SC/EERE Workshop to Identify Research Needs and Impacts in Predictive Simulation for Internal Combustion Engines (PreSICE), held March 3, 2011, to determine strategic focus areas that will accelerate innovation in engine design to meet national goals in transportation efficiency.

The U.S. has reached a pivotal moment when pressures of energy security, climate change, and economic competitiveness converge. Oil prices remain volatile and have exceeded $100 per barrel twice in five years. At these prices, the U.S. spends $1 billion per day on imported oil to meet our energy demands. Because the transportation sector accounts for two-thirds of our petroleum use, energy security is deeply entangled with our transportation needs. At the same time, transportation produces one-quarter of the nation’s carbon dioxide output. Increasing the efficiency of internal combustion engines is a technologically proven and cost-effective approach to dramatically improving the fuel economy of the nation’s fleet of vehicles in the near- to mid-term, with the corresponding benefits of reducing our dependence on foreign oil and reducing carbon emissions. Because of their relatively low cost, high performance, and ability to utilize renewable fuels, internal combustion engines—including those in hybrid vehicles—will continue to be critical to our transportation infrastructure for decades. Achievable advances in engine technology can improve the fuel economy of automobiles by over 50% and trucks by over 30%. Achieving these goals will require the transportation sector to compress its product development cycle for cleaner, more efficient engine technologies by 50% while simultaneously exploring innovative design space. Concurrently, fuels will also be evolving, adding another layer of complexity and further highlighting the need for efficient product development cycles. Current design processes, using “build and test” prototype engineering, will not suffice. Current market penetration of new engine technologies is simply too slow—it must be dramatically accelerated.

These challenges present a unique opportunity to marshal U.S. leadership in science-based simulation to develop predictive computational design tools for use by the transportation industry. The use of predictive simulation tools for enhancing combustion engine performance will shrink engine development timescales, accelerate time to market, and reduce development costs, while ensuring the timely achievement of energy security and emissions targets and enhancing U.S. industrial competitiveness.

In 2007 Cummins achieved a milestone in engine design by bringing a diesel engine to market solely with computer modeling and analysis tools. The only testing was after the fact to confirm performance. Cummins achieved a reduction in development time and cost. As important, they realized a more robust design, improved fuel economy, and met all environmental and customer constraints. This important first step demonstrates the potential for computational engine design. But, the daunting complexity of engine combustion and the revolutionary increases in efficiency needed require the development of simulation codes and computation platforms far more advanced than those available today.

Based on these needs, a Workshop to Identify Research Needs and Impacts in Predictive Simulation for Internal Combustion Engines (PreSICE) convened over 60 U.S. leaders in the engine combustion field from industry, academia, and national laboratories to focus on two critical areas of advanced simulation, as identified by the U.S. automotive and engine industries. First, modern engines require precise control of the injection of a broad variety of fuels that is far more subtle than achievable to date and that can be obtained only through predictive modeling and simulation. Second, the simulation, understanding, and control of these stochastic in-cylinder combustion processes lie on the critical path to realizing more efficient engines with greater power density. Fuel sprays set the initial conditions for combustion in essentially all future transportation engines; yet today designers primarily use empirical methods that limit the efficiency achievable. Three primary spray topics were identified as focus areas in the workshop:

The fuel delivery system, which includes fuel manifolds and internal injector flow,
The multi-phase fuel–air mixing in the combustion chamber of the engine, and
The heat transfer and fluid interactions with cylinder walls.

Current understanding and modeling capability of stochastic processes in engines remains limited and prevents designers from achieving significantly higher fuel economy. To improve this situation, the workshop participants identified three focus areas for stochastic processes:

Improve fundamental understanding that will help to establish and characterize the physical causes of stochastic events,
Develop physics-based simulation models that are accurate and sensitive enough to capture performance-limiting variability, and
Quantify and manage uncertainty in model parameters and boundary conditions.

Improved models and understanding in these areas will allow designers to develop engines with reduced design margins and that operate reliably in more efficient regimes. All of these areas require improved basic understanding, high-fidelity model development, and rigorous model validation. These advances will greatly reduce the uncertainties in current models and improve understanding of sprays and fuel–air mixture preparation that limit the investigation and development of advanced combustion technologies.

The two strategic focus areas have distinctive characteristics but are inherently coupled. Coordinated activities in basic experiments, fundamental simulations, and engineering-level model development and validation can be used to successfully address all of the topics identified in the PreSICE workshop. The outcome will be:

New and deeper understanding of the relevant fundamental physical and chemical processes in advanced combustion technologies,
Implementation of this understanding into models and simulation tools appropriate for both exploration and design, and
Sufficient validation with uncertainty quantification to provide confidence in the simulation results.

These outcomes will provide the design tools for industry to reduce development time by up to 30% and improve engine efficiencies by 30% to 50%. The improved efficiencies applied to the national mix of transportation applications have the potential to save over 5 million barrels of oil per day, a current cost savings of $500 million per day.

JPG
Report

Report of the Basic Energy Sciences Workshop on Compact Light Sources

This report is based on a BES Workshop on Compact Light Sources, held May 11-12, 2010, to evaluated the advantages and disadvantages of compact light source approaches and compared their performance to the third generation storage rings and free-electron lasers. The workshop examined the state of the technology for compact light sources and their expected progress. The workshop evaluated the cost efficiency, user access, availability, and reliability of such sources. Working groups evaluated the advantages and disadvantages of Compact Light Source (CLS) approaches, and compared their performance to the third-generation storage rings and free-electron lasers (FELs). The primary aspects of comparison were 1) cost effectiveness, 2) technical availability v. time frame, and 3) machine reliability and availability for user access. Five categories of potential sources were analyzed: 1) inverse Compton scattering (ICS) sources, 2) mini storage rings, 3) plasma sources, 4) sources using plasma-based accelerators, and 5) laser high harmonic generation (HHG) sources.

Compact light sources are not a substitute for large synchrotron and FEL light sources that typically also incorporate extensive user support facilities. Rather they offer attractive, complementary capabilities at a small fraction of the cost and size of large national user facilities. In the far term they may offer the potential for a new paradigm of future national user facility. In the course of the workshop, we identified overarching R&D topics over the next five years that would enhance the performance potential of both compact and large-scale sources:

Development of infrared (IR) laser systems delivering kW-class average power with femtosecond pulses at kHz repetition rates. These have application to ICS sources, plasma sources, and HHG sources.
Development of laser storage cavities for storage of 10-mJ picosecond and femtosecond pulses focused to micron beam sizes.
Development of high-brightness, high-repetition-rate electron sources.
Development of continuous wave (cw) superconducting rf linacs operating at 4 K, while not essential, would reduce capital and operating cost.

New Science for a Secure and Sustainable Energy Future
JPG
Report

Basic Research Needs for Carbon Capture: Beyond 2020

This report is based on a SC/FE workshop on Carbon Capture: Beyond 2020, held March 4–5, 2010, to assess the basic research needed to address the current technical bottlenecks in carbon capture processes and to identify key research priority directions that will provide the foundations for future carbon capture technologies.

The problem of thermodynamically efficient and scalable carbon capture stands as one of the greatest challenges for modern energy researchers. The vast majority of US and global energy use derives from fossil fuels, the combustion of which results in the emission of carbon dioxide into the atmosphere. These anthropogenic emissions are now altering the climate. Although many alternatives to combustion are being considered, the fact is that combustion will remain a principal component of the global energy system for decades to come. Today’s carbon capture technologies are expensive and cumbersome and energy intensive. If scientists could develop practical and cost-effective methods to capture carbon, those methods would at once alter the future of the largest industry in the world and provide a technical solution to one of the most vexing problems facing humanity.

The carbon capture problem is a true grand challenge for today’s scientists. Postcombustion CO2 capture requires major new developments in disciplines spanning fundamental theoretical and experimental physical chemistry, materials design and synthesis, and chemical engineering. To start with, the CO2 molecule itself is thermodynamically stable and binding to it requires a distortion of the molecule away from its linear and symmetric arrangement. This binding of the gas molecule cannot be too strong, however; the sheer quantity of CO2 that must be captured ultimately dictates that the capture medium must be recycled over and over. Hence the CO2 once bound, must be released with relatively little energy input. Further, the CO2 must be rapidly and selectively pulled out of a mixture that contains many other gaseous components. The related processes of precombustion capture and oxycombustion pose similar challenges. It is this nexus of high-speed capture with high selectivity and minimal energy loss that makes this a true grand challenge problem, far beyond any of today’s artificial molecular manipulation technologies, and one whose solution will drive the advancement of molecular science to a new level of sophistication.

We have only to look to nature, where such chemical separations are performed routinely, to imagine what may be achieved. The hemoglobin molecule transports oxygen in the blood rapidly and selectively and releases it with minimal energy penalty. Despite our improved understanding of how this biological system works, we have yet to engineer a molecular capture system that uses the fundamental cooperativity process that lies at the heart of the functionality of hemoglobin. While such biological examples provide inspiration, we also note that newly developed theoretical and computational capabilities; the synthesis of new molecules, materials, and membranes; and the remarkable advances in characterization techniques enabled by the Department of Energy’s measurement facilities all create a favorable environment for a major new basic research push to solve the carbon capture problem within the next decade.

The Department of Energy has established a comprehensive strategy to meet the nation’s needs in the carbon capture arena. This framework has been developed following a series of workshops that have engaged all the critical stakeholder communities. The strategy that has emerged is based upon a tiered approach, with Fossil Energy taking the lead in a series of applied research programs that will test and extend our current systems. ARPA-E (Advanced Research Projects Agency–Energy) is supporting potential breakthroughs based upon innovative proposals to rapidly harness today’s technical capabilities in ways not previously considered. These needs and plans have been well summarized in the report from a recent workshop—Carbon Capture 2020, held in October 5 and 6, 2009—focused on near-term strategies for carbon capture improvements (http://www.netl.doe.gov/publications/ proceedings/09/CC2020/pdfs/Richards_Summary.pdf ). Yet the fact remains that when the carbon capture problem is looked at closely, we see today’s technologies fall far short of making carbon capture an economically viable process. This situation reinforces the need for a parallel, intensive use-inspired basic research effort to address the problem. This was the overwhelming conclusion of a recent workshop—Carbon Capture: Beyond 2020, held March 4 and 5, 2010—and is the subject of the present report. To prepare for the second workshop, an in-depth assessment of current technologies for carbon capture was conducted; the result of this study was a factual document, Technology and Applied R&D Needs for Carbon Capture: Beyond 2020. This document, which was prepared by experts in current carbon capture processes, also summarized the technological gaps or bottlenecks that limit currently available carbon capture technologies. The report considered the separation processes needed for all three CO2 emission reduction strategies—postcombustion, precombustion, and oxycombustion—and assessed three primary separation technologies based on liquid absorption, membranes, and solid adsorption.

The workshop “Carbon Capture: Beyond 2020” convened approximately 80 attendees from universities, national laboratories, and industry to assess the basic research needed to address the current technical bottlenecks in carbon capture processes and to identify key research priority directions that will provide the foundations for future carbon capture technologies. The workshop began with a plenary session including speakers who summarized the extent of the carbon capture challenge, the various current approaches, and the limitations of these technologies. Workshop attendees were then given the charge to identify high-priority basic research directions that could provide revolutionary new concepts to form the basis for separation technologies in 2020 and beyond. The participants were divided into three major panels corresponding to different approaches for separating gases to reduce carbon emissions—liquid absorption, solid adsorption, and membrane separations. Two other panels were instructed to attend each of these three technology panels to assess crosscutting issues relevant to characterization and computation. At the end of the workshop, a final plenary session was convened to summarize the most critical research needs identified by the workshop attendees in each of the three major technical panels and from the two cross-cutting panels.

The reports of the three technical panels included a set of high level Priority Research Directions meant to serve as inspiration to researchers in multiple disciplines—materials science, chemistry, biology, computational science, engineering, and others—to address the huge scientific challenges facing this nation and the world as we seek technologies for large-scale carbon capture beyond 2020. These Priority Research Directions were clustered around three main areas, all tightly coupled:

Understand and control the dynamic atomic-level and molecular-level interactions of the targeted species with the separation media.
Discover and design new materials that incorporate designed structures and functionalities tuned for optimum separation properties.
Tailor capture/release processes with alternative driving forces, taking advantage of a new generation of materials.

In each of the technical panels, the participants identified two major crosscutting research themes. The first was the development of new analytical tools that can characterize materials structure and molecular processes across broad spatial and temporal scales and under realistic conditions that mimic those encountered in actual separation processes. Such tools are needed to examine interfaces and thin films at the atomic and molecular levels, achieving an atomic/molecular-scale understanding of gas–host structures, kinetics, and dynamics, and understanding and control of nanoscale synthesis in multiple dimensions. A second major crosscutting theme was the development of new computational tools for theory, modeling, and simulation of separation processes. Computational techniques can be used to elucidate mechanisms responsible for observed separations, predict new desired features for advanced separations materials, and guide future experiments, thus complementing synthesis and characterization efforts. These two crosscut areas underscored the fact that the challenge for future carbon capture technologies will be met only with multidisciplinary teams of scientists and engineers. In addition, it was noted that success in this fundamental research area must be closely coupled with successful applied research to ensure the continuing assessment and maturation of new technologies as they undergo scale-up and deployment.

Carbon capture is a very rich scientific problem, replete with opportunity for basic researchers to advance the frontiers of science as they engage on one of the most important technical challenges of our times. This workshop report outlines an ambitious agenda for addressing the very difficult problem of carbon capture by creating foundational new basic science. This new science will in turn pave the way for many additional advances across a broad range of scientific disciplines and technology sectors.

JPG
Report

Computational Materials Science and Chemistry: Accelerating Discovery and Innovation through Simulation-Based Engineering and Science

This report is based on a SC Workshop on Computational Materials Science and Chemistry for Innovation on July 26-27, 2010, to assess the potential of state-of-the-art computer simulations to accelerate understanding and discovery in materials science and chemistry, with a focus on potential impacts in energy technologies and innovation.

The urgent demand for new energy technologies has greatly exceeded the capabilities of today's materials and chemical processes. To convert sunlight to fuel, efficiently store energy, or enable a new generation of energy production and utilization technologies requires the development of new materials and processes of unprecedented functionality and performance. New materials and processes are critical pacing elements for progress in advanced energy systems and virtually all industrial technologies.

Over the past two decades, the United States has developed and deployed the world's most powerful collection of tools for the synthesis, processing, characterization, and simulation and modeling of materials and chemical systems at the nanoscale, dimensions of a few atoms to a few hundred atoms across. These tools, which include world-leading x-ray and neutron sources, nanoscale science facilities, and high-performance computers, provide an unprecedented view of the atomic-scale structure and dynamics of materials and the molecular-scale basis of chemical processes. For the first time in history, we are able to synthesize, characterize, and model materials and chemical behavior at the length scale where this behavior is controlled. This ability is transformational for the discovery process and, as a result, confers a significant competitive advantage.

Perhaps the most spectacular increase in capability has been demonstrated in high performance computing. Over the past decade, computational power has increased by a factor of a million due to advances in hardware and software. This rate of improvement, which shows no sign of abating, has enabled the development of computer simulations and models of unprecedented fidelity.

We are at the threshold of a new era where the integrated synthesis, characterization, and modeling of complex materials and chemical processes will transform our ability to understand and design new materials and chemistries with predictive power. In turn, this predictive capability will transform technological innovation by accelerating the development and deployment of new materials and processes in products and manufacturing.

Harnessing the potential of computational science and engineering for the discovery and development of materials and chemical processes is essential to maintaining leadership in these foundational fields that underpin energy technologies and industrial competitiveness. Capitalizing on the opportunities presented by simulation-based engineering and science in materials and chemistry will require an integration of experimental capabilities with theoretical and computational modeling; the development of a robust and sustainable infrastructure to support the development and deployment of advanced computational models; and the assembly of a community of scientists and engineers to implement this integration and infrastructure. This community must extend to industry, where incorporating predictive materials science and chemistry into design tools can accelerate the product development cycle and drive economic competitiveness.

The confluence of new theories, new materials synthesis capabilities, and new computer platforms has created an unprecedented opportunity to implement a "materials-by-design" paradigm with wide-ranging benefits in technological innovation and scientific discovery. The Workshop on Computational Materials Science and Chemistry for Innovation was convened in Bethesda, Maryland, on July 26-27, 2010. Sponsored by the Department of Energy (DOE) Offices of Advanced Scientific Computing Research and Basic Energy Sciences, the workshop brought together 160 experts in materials science, chemistry, and computational science representing more than 65 universities, laboratories, and industries, and four agencies.

The workshop examined seven foundational challenge areas in materials science and chemistry: materials for extreme conditions, self-assembly, light harvesting, chemical reactions, designer fluids, thin films and interfaces, and electronic structure. Each of these challenge areas is critical to the development of advanced energy systems, and each can be accelerated by the integrated application of predictive capability with theory and experiment.

The workshop concluded that emerging capabilities in predictive modeling and simulation have the potential to revolutionize the development of new materials and chemical processes. Coupled with world-leading materials characterization and nanoscale science facilities, this predictive capability provides the foundation for an innovation ecosystem that can accelerate the discovery, development, and deployment of new technologies, including advanced energy systems. Delivering on the promise of this innovation ecosystem requires the following:

Integration of synthesis, processing, characterization, theory, and simulation and modeling. Many of the newly established Energy Frontier Research Centers and Energy Hubs are exploiting this integration.
Achieving/strengthening predictive capability in foundational challenge areas. Predictive capability in the seven foundational challenge areas described in this report is critical to the development of advanced energy technologies.
Developing validated computational approaches that span vast differences in time and length scales. This fundamental computational challenge crosscuts all of the foundational challenge areas. Similarly challenging is coupling of analytical data from multiple instruments and techniques that are required to link these length and time scales.
Experimental validation and quantification of uncertainty in simulation and modeling. Uncertainty quantification becomes increasingly challenging as simulations become more complex.
Robust and sustainable computational infrastructure, including software and applications. For modeling and simulation, software equals infrastructure. To validate the computational tools, software is critical infrastructure that effectively translates huge arrays of experimental data into useful scientific understanding. An integrated approach for managing this infrastructure is essential.
Efficient transfer and incorporation of simulation-based engineering and science in industry. Strategies for bridging the gap between research and industrial applications and for widespread industry adoption of integrated computational materials engineering are needed.

JPG
Report
Report
Summary

New Science for a Secure and Sustainable Energy Future

This Basic Energy Sciences Advisory Committee (BESAC) report summarizes a 2008 study by the Subcommittee on Facing our Energy Challenges in a New Era of Science to: (1) assimilate the scientific research directions that emerged from the BES Basic Research Needs workshop reports into a comprehensive set of science themes, and (2) identify the new implementation strategies and tools required to accomplish the science.

The United States faces a three-fold energy challenge:

Energy Independence. U.S. energy use exceeds domestic production capacity by the equivalent of 16 million barrels of oil per day, a deficit made up primarily by importing oil and natural gas. This deficit has nearly tripled since 1970.
Environmental Sustainability. The United States must reduce its emissions of carbon dioxide and other greenhouse gases that accelerate climate change. The primary source of these emissions is combustion of fossil fuel, comprising about 85% of U.S. national energy supply.
Economic Opportunity. The U.S. economy is threatened by the high cost of imported energy—as much as $700 billion per year at recent peak prices. We need to create next-generation clean energy technologies that do not depend on imported oil. U.S. leadership would not only provide solutions at home but also create global economic opportunity.

The magnitude of the challenge is so immense that existing energy approaches—even with improvements from advanced engineering and improved technology based on known concepts—will not be enough to secure our energy future. Instead, meeting the challenge will require new technologies for producing, storing and using energy with performance levels far beyond what is now possible. Such technologies spring from scientific breakthroughs in new materials and chemical processes that govern the transfer of energy between light, electricity and chemical fuels. Integrating a major national mobilization of basic energy research—to create needed breakthroughs—with appropriate investments in technology and engineering to accelerate bringing new energy solutions to market will be required to meet our three-fold energy challenge. This report identifies three strategic goals for which transformational scientific breakthroughs are urgently needed:

Making fuels from sunlight
Generating electricity without carbon dioxide emissions
Revolutionizing energy efficiency and use

Meeting these goals implies dramatic changes in our technologies for producing and consuming energy. We will manufacture chemical fuel from sunlight, water and carbon dioxide instead of extracting it from the earth. We will generate electricity from sunlight, wind, and high-efficiency clean coal and advanced nuclear plants instead of conventional coal and nuclear technology. Our cars and light trucks will be driven by efficient electric motors powered by a new generation of batteries and fuel cells.

These new, advanced energy technologies, however, require new materials and control of chemical change that operate at dramatically higher levels of functionality and performance. Converting sunlight to electricity with double or triple today's efficiency, storing electricity in batteries or supercapacitors at ten times today's densities, or operating coal-fired and nuclear power plants at far higher temperatures and efficiencies requires materials with atom by atom design and control, tailored nanoscale structures where every atom has a specific function. Such high performing materials would have complexity far higher than today's energy materials, approaching that of biological cells and proteins. They would be able to seamlessly control the ebb and flow of energy between chemical bonds, electrons, and light, and would be the foundation of the alternative energy technologies of the future.

Creating these advanced materials and chemical processes requires characterizing the structure and dynamics of matter at levels beyond our present reach. The physical and chemical phenomena that capture, store and release energy take place at the nanoscale, often involving subtle changes in single electrons or atoms, on timescales faster than we can now resolve. Penetrating the secrets of energy transformation between light, chemical bonds, and electrons requires new observational tools capable of probing the still-hidden realms of the ultrasmall and ultrafast. Observing the dynamics of energy flow in electronic and molecular systems at these resolutions is necessary if we are to learn to control their behavior.

Fundamental understanding of complex materials and chemical change based on theory, computation and advanced simulation is essential to creating new energy technologies. A working transistor was not developed until the theory of electronic behavior on semiconductor surfaces was formulated. In superconductivity, sweeping changes occurred in the field when a microscopic theory of the mechanism of superconductivity was finally developed. As Nobel Laureate Phillip Anderson has written, more is different: at each level of complexity in science, new laws need to be discovered for breakthrough progress to be made. Without such breakthroughs, future technologies will not be realized. The digital revolution was only made possible by transistors—try to imagine the information age with vacuum tubes. Nearly as ubiquitous are lasers, the basis for modern day read-heads used in CDs, DVDs, and bar code scanners. Lasers could not be developed until the quantum theory of light emission by materials was understood.

These advances—high-performance materials enabling precise control of chemical change, characterization tools probing the ultrafast and the ultrasmall, and new understanding based on advanced theory and simulation—are the agents for moving beyond incremental improvements and creating a truly secure and sustainable energy future.

Given these tools, we can imagine, and achieve, revolutionary new energy systems.

Full Report
(August 2010)

Science for Energy Technology: Strengthening the Link between Basic Research and Industry, Full Report

JPG
Report
Report

Initial Report
(April 2010)

JPG
Report
Report
Summary

Science for Energy Technology: Strengthening the Link between Basic Research and Industry

This Basic Energy Sciences Advisory Committee (BESAC) report summarizes the results of a

Workshop on Science for Energy Technology on January 18-21, 2010, to identify the scientific priority research directions needed to address the roadblocks and accelerate the innovation of clean energy technologies.

The nation faces two severe challenges that will determine our prosperity for decades to come: assuring clean, secure, and sustainable energy to power our world, and establishing a new foundation for enduring economic and jobs growth. These challenges are linked: the global demand for clean sustainable energy is an unprecedented economic opportunity for creating jobs and exporting energy technology to the developing and developed world. But achieving the tremendous potential of clean energy technology is not easy. In contrast to traditional fossil fuel-based technologies, clean energy technologies are in their infancy, operating far below their potential, with many scientific and technological challenges to overcome.

Industry is ultimately the agent for commercializing clean energy technology and for reestablishing the foundation for our economic and jobs growth. For industry to succeed in these challenges, it must overcome many roadblocks and continuously innovate new generations of renewable, sustainable, and low-carbon energy technologies such as solar energy, carbon sequestration, nuclear energy, electricity delivery and efficiency, solid state lighting, batteries and biofuels. The roadblocks to higher performing clean energy technology are not just challenges of engineering design but are also limited by scientific understanding. Innovation relies on contributions from basic research to bridge major gaps in our understanding of the phenomena that limit efficiency, performance, or lifetime of the materials or chemistries of these sustainable energy technologies. Thus, efforts aimed at understanding the scientific issues behind performance limitations can have a real and immediate impact on cost, reliability, and performance of technology, and ultimately a transformative impact on our economy.

With its broad research base and unique scientific user facilities, the DOE Office of Basic Energy Sciences (BES) is ideally positioned to address these needs. BES has laid out a broad view of the basic and grand challenge science needs for the development of future clean energy technologies in a series of comprehensive "Basic Research Needs" workshops and reports (inside front cover and http://www.sc.doe.gov/bes/reports/list.html) and has structured its programs and launched initiatives to address the challenges.

The basic science needs of industry, however, are often more narrowly focused on solving specific nearer-term roadblocks to progress in existing and emerging clean energy technologies. To better define these issues and identify specific barriers to progress, the Basic Energy Sciences Advisory Committee (BESAC) sponsored the Workshop on Science for Energy Technology, January 18-21, 2010. A wide cross-section of scientists and engineers from industry, universities, and national laboratories delineated the basic science Priority Research Directions most urgently needed to address the roadblocks and accelerate the innovation of clean energy technologies. These Priority Research Directions address the scientific understanding underlying performance limitations in existing but still immature technologies. Resolving these performance limitations can dramatically improve the commercial penetration of clean energy technologies.

A key conclusion of the Workshop is that in addition to the decadal challenges defined in the "Basic Research Needs" reports, specific research directions addressing industry roadblocks are ripe for further emphasis. Another key conclusion is that identifying and focusing on specific scientific challenges and translating the results to industry requires more direct feedback and communication and collaboration between industrial and BES-supported scientists. BES-supported scientists need to be better informed of the detailed scientific issues facing industry, and industry more aware of BES capabilities and how to utilize them. An important capability is the suite of BES scientific user facilities, which are seen as playing a key role in advancing the science of clean energy technology.

Working together, industry and BES-supported scientists can achieve the required understanding and control of the performance limitations of clean energy technology, accelerate innovation in its development, and help build the workforce needed to implement the growing clean energy economy.

JPG
Report
Report

Next-Generation Photon Sources for Grand Challenges in Science and Energy

This Basic Energy Sciences Advisory Committee (BESAC) report summarizes the results of an October 2008 Photon Workshop of the Subcommittee on Facing our Energy Challenges in a New Era of Science to identify connections between major new research opportunities and the capabilities of the next generation of light sources. Particular emphasis was on energy-related research.

The next generation of sustainable energy technologies will revolve around transformational new materials and chemical processes that convert energy efficiently among photons, electrons, and chemical bonds. New materials that tap sunlight, store electricity, or make fuel from splitting water or recycling carbon dioxide will need to be much smarter and more functional than today's commodity-based energy materials. To control and catalyze chemical reactions or to convert a solar photon to an electron requires coordination of multiple steps, each carried out by customized materials and interfaces with designed nanoscale structures. Such advanced materials are not found in nature the way we find fossil fuels; they must be designed and fabricated to exacting standards, using principles revealed by basic science. Success in this endeavor requires probing, and ultimately controlling, the interactions among photons, electrons, and chemical bonds on their natural length and time scales.

Control science—the application of knowledge at the frontier of science to control phenomena and create new functionality—realized through the next generation of ultraviolet and X-ray photon sources, has the potential to be transformational for the life sciences and information technology, as well as for sustainable energy. Current synchrotron-based light sources have revolutionized macromolecular crystallography. The insights thus obtained are largely in the domain of static structure. The opportunity is for next generation light sources to extend these insights to the control of dynamic phenomena through ultrafast pump-probe experiments, time-resolved coherent imaging, and high-resolution spectroscopic imaging. Similarly, control of spin and charge degrees of freedom in complex functional materials has the potential not only to reveal the fundamental mechanisms of high-temperature superconductivity, but also to lay the foundation for future generations of information science.

This report identifies two aspects of energy science in which next-generation ultraviolet and X-ray light sources will have the deepest and broadest impact:

The temporal evolution of electrons, spins, atoms, and chemical reactions, down to the femtosecond time scale.
Spectroscopic and structural imaging of nano objects (or nanoscale regions of inhomogeneous materials) with nanometer spatial resolution and ultimate spectral resolution.

The dual advances of temporal and spatial resolution promised by fourth-generation light sources ideally match the challenges of control science. Femtosecond time resolution has opened completely new territory where atomic motion can be followed in real time and electronic excitations and decay processes can be followed over time. Coherent imaging with short-wavelength radiation will make it possible to access the nanometer length scale, where intrinsic quantum behavior becomes dominant. Performing spectroscopy on individual nanometer-scale objects rather than on conglomerates will eliminate the blurring of the energy levels induced by particle size and shape distributions and reveal the energetics of single functional units. Energy resolution limited only by the uncertainty relation is enabled by these advances.

Current storage-ring-based light sources and their incremental enhancements cannot meet the need for femtosecond time resolution, nanometer spatial resolution, intrinsic energy resolution, full coherence over energy ranges up to hard X-rays, and peak brilliance required to enable the new science outlined in this report. In fact, the new, unexplored territory is so expansive that no single currently imagined light source technology can fulfill the whole potential. Both technological and economic challenges require resolution as we move forward. For example, femtosecond time resolution and high peak brilliance are required for following chemical reactions in real time, but lower peak brilliance and high repetition rate are needed to avoid radiation damage in high-resolution spatial imaging and to avoid space-charge broadening in photoelectron spectroscopy and microscopy.

But light sources alone are not enough. The photons produced by next-generation light sources must be measured by state-of-the-art experiments installed at fully equipped end stations. Sophisticated detectors with unprecedented spatial, temporal, and spectral resolution must be designed and created. The theory of ultrafast phenomena that have never before been observed must be developed and implemented. Enormous data sets of diffracted signals in reciprocal space and across wide energy ranges must be collected and analyzed in real time so that they can guide the ongoing experiments. These experimental challenges—end stations, detectors, sophisticated experiments, theory, and data handling—must be planned and provided for as part of the photon source. Furthermore, the materials and chemical processes to be studied, often in situ, must be synthesized and developed with equal care. These are the primary factors determining the scientific and technological return on the photon source investment.

Of equal or greater concern is the need for interdisciplinary platforms to solve the grand challenges of sustainable energy, climate change, information technology, biological complexity, and medicine. No longer are these challenges confined to one measurement or one scientific discipline. Fundamental problems in correlated electron materials, where charge, spin, and lattice modes interact strongly, require experiments in electron, neutron, and X-ray scattering that must be coordinated across platforms and user facilities and that integrate synthesis and theory as well. The model of users applying for one-time access to single-user facilities does not promote the coordinated, interdisciplinary approach needed to solve today's grand challenge problems. Next-generation light sources and other user facilities must learn to accommodate the interdisciplinary, cross-platform needs of modern grand challenge science. Only through the development of such future sources, appropriately integrated with advanced end stations and detectors and closely coupled with broader synthesis, measurement, theory, and modeling tools, can we meet the demands of a New Era of Science.

JPG
Report

Directing Matter and Energy: Five Challenges for Science and the Imagination

This Basic Energy Sciences Advisory Committee (BESAC) Grand Challenges report identifies the most important scientific questions and science-driven technical challenges facing BES and describes the importance of these challenges to advances in disciplinary science, to technology development, and to energy and other societal needs. The report originated from a January 25, 2005, request from the Office of Science and is the product of numerous BESAC and Grand Challenges Subcommittee meetings and conferences in 2006-2007.

It is frequently said that any sufficiently advanced technology is indistinguishable from magic. Modern science stands at the beginning of what might seem by today's standards to be an almost magical leap forward in our understanding and control of matter, energy, and information at the molecular and atomic levels. Atoms—and the molecules they form through the sharing or exchanging of electrons—are the building blocks of the biological and non-biological materials that make up the world around us. In the 20th century, scientists continually improved their ability to observe and understand the interactions among atoms and molecules that determine material properties and processes. Now, scientists are positioned to begin directing those interactions and controlling the outcomes on a molecule-by-molecule and atom-by-atom basis, or even at the level of electrons. Long the staple of science- fiction novels and films, the ability to direct and control matter at the quantum, atomic, and molecular levels creates enormous opportunities across a wide spectrum of critical technologies. This ability will help us meet some of humanity's greatest needs, including the need for abundant, clean, and cheap energy. However, generating, storing, and distributing adequate and sustainable energy to the nation and the world will require a sea change in our ability to control matter and energy.

One of the most spectacular technological advances in the 20th century took place in the field of information, as computers and microchips became ubiquitous in our society. Vacuum tubes were replaced with transistors and, in accordance with Moore's Law (named for Intel co-founder Gordon Moore), the number of transistors on a microchip has doubled approximately every two years for the past two decades. However, if the time comes when integrated circuits can be fabricated at the molecular or nanoscale level, the limits of Moore's Law will be far surpassed. A supercomputer based on nanochips would comfortably fit in the palm of your hand and use less electricity than a cottage. All the information stored in the Library of Congress could be contained in a memory the size of a sugar cube. Ultimately, if computations can be carried out at the atomic or sub-nanoscale levels, today's most powerful microtechnology will seem as antiquated and slow as an abacus.

For the future, imagine a clean, cheap, and virtually unlimited supply of electrical power from solar-energy systems modeled on the photosynthetic processes utilized by green plants, and power lines that could transmit this electricity from the deserts of the Southwest to the Eastern Seaboard at nearly 100-percent efficiency. Imagine information and communications systems based on light rather than electrons that could predict when and where hurricanes make landfall, along with self-repairing materials that could survive those hurricanes. Imagine synthetic materials fully compatible and able to communicate with biological materials. This is speculative to be sure, but not so very far beyond the scope of possibilities.

Acquiring the ability to direct and control matter all the way down to molecular, atomic, and electronic levels will require fundamental new knowledge in several critical areas. This report was commissioned to define those knowledge areas and the opportunities that lie beyond. Five interconnected Grand Challenges that will pave the way to a science of control are identified in the regime of science roughly defined by the Basic Energy Science portfolio, and recommendations are presented for what must be done to meet them.

FIVE GRAND CHALLENGES FOR BASIC ENERGY SCIENCES

How do we control material processes at the level of electrons?

Electrons are the negatively charged subatomic particles whose dynamics determine materials properties and direct chemical, electrical, magnetic, and physical processes. If we can learn to direct and control material processes at the level of electrons, where the strange laws of quantum mechanics rule, it should pave the way for artificial photosynthesis and other highly efficient energy technologies, and could revolutionize computer technologies.
How do we design and perfect atom- and energy- efficient synthesis of revolutionary new forms of matter with tailored properties?

Humans, through trial and error experiments or through lucky accidents, have been able to make only a tiny fraction of all the materials that are theoretically possible. If we can learn to design and create new materials with tailored properties, it could lead to low-cost photovoltaics, self-repairing and self-regulating devices, integrated photonic (light-based) technologies, and nano-sized electronic and mechanical devices.
How do remarkable properties of matter emerge from complex correlations of the atomic or electronic constituents and how can we control these properties?

Emergent phenomena, in which a complex outcome emerges from the correlated interactions of many simple constituents, can be widely seen in nature, as in the interactions of neurons in the human brain that result in the mind, the freezing of water, or the giant magneto-resistance behavior that powers disk drives. If we can learn the fundamental rules of correlations and emergence and then learn how to control them, we could produce, among many possibilities, an entirely new generation of materials that supersede present-day semiconductors and superconductors.
How can we master energy and information on the nanoscale to create new technologies with capabilities rivaling those of living things?

Biology is nature's version of nanotechnology, though the capabilities of biological systems can exceed those of human technologies by a vast margin. If we can understand biological functions and harness nanotechnologies with capabilities as effective as those of biological systems, it should clear the way towards profound advances in a great many scientific fields, including energy and information technologies.
How do we characterize and control matter away—especially very far away—from equilibrium?

All natural and most human-induced phenomena occur in systems that are away from the equilibrium in which the system would not change with time. If we can understand system effects that take place away—especially very far away—from equilibrium and learn to control them, it could yield dramatic new energy-capture and energy storage technologies, greatly improve our predictions for molecular-level electronics, and enable new mitigation strategies for environmental damage.

We now stand at the brink of a "Control Age" that could spark revolutionary changes in how we inhabit our planet, paving the way to a bright and sustainable future for us all. But answering the call of the five Grand Challenges for Basic Energy Science will require that we change our fundamental understanding of how nature works. This will necessitate a three-fold attack: new approaches to training and funding, development of instruments more precise and flexible than those used up to now for observational science, and creation of new theories and concepts beyond those we currently possess. The difficulties involved in this change of our understanding are huge, but the rewards for success should be extraordinary. If we succeed in meeting these five Grand Challenges, our ability to direct and control matter might one day be measured only by the limits of human imagination.

JPG
Report
Report

Basic Research Needs for Materials under Extreme Environments

This report is based on a BES Workshop on Basic Research Needs for Materials under Extreme Environments, June 11-13, 2007, to evaluate the potential for developing revolutionary new materials that will meet demanding future energy requirements that expose materials to environmental extremes.

Never has the world been so acutely aware of the inextricably linked issues of energy, environment, economy, and security. As the economies of developing countries boom, so does their demand for energy. Today nearly a quarter of the world does not have electrical power, yet the demand for electricity is projected to more than double over the next two decades. Increased demand for energy to power factories, transport commodities and people, and heat/cool homes also results in increased CO₂ emissions. In 2007 China, a major consumer of coal, surpassed the United States in overall carbon dioxide emissions. As global CO₂ emissions grow, the urgency grows to produce energy from carbon-based sources more efficiently in the near term and to move to non-carbon-based energy sources, such as solar, hydrogen, or nuclear, in the longer term. As we look toward the future, two points are very clear: (1) the economy and security of this nation is critically dependent on a readily available, clean and affordable energy supply; and (2) no one energy solution will meet all future energy demands, requiring investments in development of multiple energy technologies.

Materials are central to every energy technology, and future energy technologies will place increasing demands on materials performance with respect to extremes in stress, strain, temperature, pressure, chemical reactivity, photon or radiation flux, and electric or magnetic fields. For example, today's state-of-the-art coal-fired power plants operate at about 35% efficiency. Increasing this efficiency to 60% using supercritical steam requires raising operating temperatures by nearly 50% and essentially doubling the operating pressures. These operating conditions require new materials that can reliably withstand these extreme thermal and pressure environments. To lower fuel consumption in transportation, future vehicles will demand lighter weight components with high strength. Next-generation nuclear fission reactors require materials capable of withstanding higher temperatures and higher radiation flux in highly corrosive environments for long periods of time without failure. These increasingly extreme operating environments accelerate the aging process in materials, leading to reduced performance and eventually to failure. If one extreme is harmful, two or more can be devastating. High temperature, for example, not only weakens chemical bonds, it also speeds up the chemical reactions of corrosion.

Often materials fail at one-tenth or less of their intrinsic limits, and we do not understand why. This failure of materials is a principal bottleneck for developing future energy technologies that require placing materials under increasingly extreme conditions. Reaching the intrinsic limit of materials performance requires understanding the atomic and molecular origins of this failure. This knowledge would enable an increase in materials performance of order of magnitude or more. Further, understanding how these extreme environments affect the physical and chemical processes that occur in the bulk material and at its surface would open the door to employing these conditions to make entirely new classes of materials with greatly enhanced performance for future energy technologies. This knowledge will not be achieved by incremental advances in materials science. Indeed, this knowledge will only be gained by innovative basic research that will unlock the fundamentals of how extremes environments interact with materials and how these interactions can be controlled to reach the intrinsic limits of materials performance and to develop revolutionary new materials. These new materials would have enormous impact for the development of future energy technologies: extending lifetimes, increasing efficiencies, providing novel capabilities, and lowering costs. Beyond energy applications, these new materials would have a huge impact on other areas of importance to this nation, including national security, industry, and other areas where robust, reliable materials are required.

This report summarizes the research directions identified by a Basic Energy Sciences Workshop on Basic Research Needs for Materials under Extreme Environments, held in June 2007. More than 140 invited scientists and engineers from academia, industry, and the national laboratories attended the workshop, along with representatives from other offices within the Department of Energy, including the National Nuclear Security Administration, the Office of Nuclear Energy, the Office of Energy Efficiency and Renewable Energy, and the Office of Fossil Energy. Prior to the workshop, a technology resource document, Technology and Applied R&D Needs for Materials under Extreme Environments, was prepared that provided the participants with an overview of current and future materials needs for energy technologies. The workshop began with a plenary session that outlined the technology needs and the state of the art in research of materials under extreme conditions. The workshop was then divided into four panels, focusing on specific types of extreme environments: Energetic Flux Extremes, Chemical Reactive Extremes, Thermomechanical Extremes, and Electromagnetic Extremes. The four panels were asked to assess the current status of research in each of these four areas and identify the most promising research directions that would bridge the current knowledge gaps in understanding how these four extreme environments impact materials at the atomic and molecular levels. The goal was to outline specific Priority Research Directions (PRDs) that would ultimately lead to the development of vastly improved materials across a broad range of future energy technologies. During the course of the workshop, a number of common themes emerged across these four panels and a fifth panel was charged to identify these cross-cutting research areas.

Photons and energetic particles can cause damage to materials that occurs over broad time and length scales. While initiation, characterized by localized melting and re-crystallization, may occur in fractions of a picosecond, this process can produce cascades of point defects that diffuse and agglomerate into larger clusters. These nanoscale clusters can eventually reach macroscopic dimensions, leading to decreased performance and failure. The panel on energetic flux extremes noted that this degradation and failure is a key barrier to achieving more efficient energy generation systems and limits the lifetime of materials used in photovoltaics, solar collectors, nuclear reactors, optics, electronics and other energy and security systems used in extreme flux environments. The panel concluded that the ability to prevent this degradation from extreme fluxes is critically dependent on being able to elucidate the atomic- and molecular-level mechanisms of defect production and damage evolution triggered by single and multiple energetic particles and photons interacting with materials. Advances in characterization and computational tools have the potential to provide an unprecedented opportunity to elucidate these key mechanisms. In particular, ultrafast and ultra-high spatial resolution characterization tools will allow the initial atomic-scale damage events to be observed. Further, advanced computational capabilities have the potential to capture multiscale damage evolution from atomic to macroscopic dimensions. Elucidation of these mechanisms would allow the complex pathways of damage evolution from the atomic to the macroscopic scale to be understood. This knowledge would ultimately allow atomic and molecular structures to be manipulated in a predicable manner to create new materials that have extraordinary tolerance and can function within an extreme environment without property degradation. Further, it would provide revolutionary capabilities for synthesizing materials with novel structures or, alternatively, to force chemical reactions that normally result in damage to proceed along selected pathways that are either benign or self-repair damage initiation.

Chemically reactive extreme environments are found in many advanced energy systems, including fuel cells, nuclear reactors, and batteries, among others. These conditions include aqueous and non-aqueous liquids (such as mineral acids, alcohols, and ionic liquids) and gaseous environments (such as hydrogen, ammonia, and steam). The panel evaluating extreme chemical environments concluded there is a lack of fundamental understanding of thermodynamic and kinetic processes that occur at the atomic level under these important reactive environments. The chemically induced degradation of materials is initiated at the interface of a material with its environment. Chemical stability in these environments is often controlled by protective surfaces, either self-healing, stable films that form on a surface (such as oxides) or by coatings that are applied to a surface. Besides providing surface stability, these films must also prevent facile mass transport of reactive species into the bulk of the material. While some films can have long lifetimes, increasing severity of environments can cause the films to break down, leading to costly materials failure. A major challenge therefore is to develop a new generation of surface layers that are extremely robust under aggressive chemical conditions. Before this can be accomplished, however, it is critical to understand the equilibrium and non-equilibrium thermodynamics and reaction kinetics that occur at the atomic level at the interface of the protective film with its environment. The stability of the film can be further complicated by differences in the material's morphology, structure, and defects. It is critical that these complex and interrelated chemical and physical processes be understood at the nanoscale using new capabilities in materials characterization and theory, modeling, and simulation. Armed with this information, it will be possible to develop a new generation of robust surface films to protect materials in extreme chemical environments. Further, this understanding will provide insight into developing films that can self-heal and to synthesizing new classes of materials that have unimaginable stability to aggressive chemical environments.

The need for materials that can withstand thermomechanical extremes—high pressure and stress, strain and strain rate, and high and low temperature—is found across a broad range of energy technologies, such as efficient steam turbines and heat exchangers, fuel-efficient vehicles, and strong wind turbine blades. Failures of materials under thermomechanical extremes can be catastrophic and costly. The panel on thermomechanical extremes concluded that designing new materials with properties specifically tailored to withstand thermomechanical extremes must begin with understanding the fundamental chemical and physical processes involved in materials failure, extending from the nanoscale to the collective behavior at the macroscale. Further, the behavior of materials must be understood under static, quasistatic, and dynamic thermomechanical extremes. This requires learning how atoms and electrons move within a material under extremes to provide insight into defect production and eventual evolution into microstructural components, such as dislocations, voids, and grain boundaries. This will require advanced analytical tools that can study materials in situ as these defects originate and evolve. Once these processes are understood, it will be possible to predict responses of materials under thermomechanical extremes using advanced computation tools. Further, this fundamental knowledge will open new avenues for designing and synthesizing materials with unique properties. Using these thermomechanical extremes will allow the very nature of chemical bonds to be tuned to produce revolutionary new materials, such as ultrahard materials.

As electrical energy demand grows, perhaps by greater than 70% over the next 50 years, so does the need to develop materials capable of operating at extreme electric and magnetic fields. To develop future electrical energy technologies, new materials are needed for magnets capable of operating at higher fields in generators and motors, insulators resistant to higher electric fields and field gradients, and conductors/superconductors capable of carrying higher current at lower voltage. The panel on electromagnetic extremes concluded that the discovery and understanding of this broad range of new materials requires revealing and controlling the defects that occur at the nanoscale. Defects are responsible for breakdown of insulators, yet defects are needed within local structures of superconductors to trap magnetic vortices. The ability to observe these defects as materials interact with electromagnetic extremes is just becoming available with advances in characterization tools with increased spatial and time resolution. Understanding how these nanoscale defects evolve to affect the macroscale behavior of materials is a grand challenge, and advances in multiscale modeling are required to understand the behavior of materials under these extremes. Once the behavior of defects in materials is understood, then materials could be designed to prevent dielectric breakdown or to enhance magnetic behavior. For example, composite materials having appropriate structures and properties could be tailored using nanoscale self-assembly techniques. The panel projected that understanding how electric and magnetic fields affect materials at the atomic and molecular level could lead to the ability to control materials properties and synthesis. Such control would lead to a new generation of materials that is just emerging today—such as electrooptic materials that can be switched between transparency and opacity through application of electric fields. Beyond energy applications, these tailored materials could have enormous importance in security, computing, electronics, and other applications.

During the course of the workshop, four recurring science issues emerged as important themes: (1) Achieving the Limits of Performance; (2) Exploiting Extreme Environments for Materials Design and Synthesis; (3) Characterization on the Scale of Fundamental Interactions; and (4) Predicting and Modeling Materials Performance. All four of the workshop panels identified the need to understand the complex and interrelated physical and chemical processes that control the various performance limits of materials subjected to extreme conditions as the major technical bottleneck in meeting future energy needs. Most of these processes involve understanding the cascade of events that is initiated at atomic-level defects and progresses through macroscopic materials properties. By understanding various mechanisms by which materials fail, for example, it may be possible to increase the performance and lifetime limits of materials by an order of magnitude or more and thereby achieve the true limits of materials performance.

Understanding the atomic and molecular basis of the interaction of extreme environments with materials provides an exciting and unique opportunity to produce entirely new classes of materials. Today materials are made primarily by changing temperature, composition, and sometimes, pressure. The panels concluded that extreme conditions—in the form of high temperatures, pressures, strain rate, radiation fluxes, or external fields, alone or in combination—can potentially be used as new "knobs" that can be manipulated for the synthesis of revolutionary new materials. All four of the extreme environments offer new strategies for controlling the atomic- and molecular-level structure in unprecedented ways to produce materials with tailored functionalities.

To achieve the breakthroughs needed to understand the atomic and molecular processes that occur within the bulk and at surfaces in materials in extreme environments will require advances in the final two cross-cutting areas, characterization and computation. Elucidating changes in structure and dynamics over broad timescales (femtoseconds to many seconds) and length scales (nanoscale to macroscale) is critical to realizing the revolutionary materials required for future energy technologies. Advances in characterization tools, including diffraction, scattering, spectroscopy, microscopy, and imaging, can provide this critical information. Of particular importance is the need to combine two or more of these characterization tools to permit so-called "multi-dimensional" analysis of materials and surfaces in situ. These advances will enable the elucidation of fundamental chemical and physical mechanisms that are at the heart of materials performance (and failure) and catalyze the discovery of new materials required for the next generation of energy technologies.

Complementing these characterization techniques are computational techniques required for modeling and predicting materials behavior under extreme conditions. Recent advances in theory and algorithms, coupled with enormous and growing computational power and ever more sophisticated experimental methods, are opening up exciting new possibilities for taking advantage of predictive theory and simulation to design and predict of the properties and performance of new materials required for extreme environments. New theoretical tools are needed to describe new phenomena and processes that occur under extreme conditions. These various tools need to be integrated across broad length scales—atomic to macroscopic—to model and predict the properties of real materials in response to extreme environments. Together with advanced synthesis and characterization techniques, these new capabilities in theory and modeling offer exciting new capabilities to accelerate scientific discovery and shorten the development cycle from discovery to application.

In concluding the workshop, the panelists were confident that today's gaps in materials performance under extreme conditions could be bridged if the physical and chemical changes that occur in bulk materials and at the interface with the extreme environment could be understood from the atomic to macroscopic scale. These complex and interrelated phenomena can be unraveled as advances are realized in characterization and computational tools. These advances will allow structural changes, including defects, to be observed in real time and then modeled so the response of materials can be predicted. The concept of exploiting these extreme environments to create revolutionary new materials was viewed to be particularly exciting. Adding these parameters to the toolkit of materials synthesis opens unimaginable possibilities for developing materials with tailored properties. The knowledge needed for bridging these technology gaps requires significant investment in basic research, and this research needs to be coupled closely with the applied research and technology communities and industry that will drive future energy technologies. These investments in fundamental research of materials under extreme conditions will have a major impact on the development of technologies that can meet future requirements for abundant, affordable, and clean energy. However, this research will enable the development of materials that will have a much broader impact in other applications that are critical to the security and economy of this nation.

JPG
Report

Basic Research Needs: Catalysis for Energy

This report is based on a BES Workshop on Basic Research Needs in Catalysis for Energy Applications, August 6-8, 2007, to identify research needs and opportunities for catalysis to meet the nation's energy needs, provide an assessment of where the science and technology now stand, and recommend the directions for fundamental research that should be pursued to meet the goals described.

The United States continues to rely on petroleum and natural gas as its primary sources of fuels. As the domestic reserves of these feedstocks decline, the volumes of imported fuels grow, and the environmental impacts resulting from fossil fuel combustion become severe, we as a nation must earnestly reassess our energy future.

Catalysis—the essential technology for accelerating and directing chemical transformation—is the key to realizing environmentally friendly, economical processes for the conversion of fossil energy feedstocks. Catalysis also is the key to developing new technologies for converting alternative feedstocks, such as biomass, carbon dioxide, and water.

With the declining availability of light petroleum feedstocks that are high in hydrogen and low in sulfur and nitrogen, energy producers are turning to ever-heavier fossil feedstocks, including heavy oils, tar sands, shale oil, and coal. Unfortunately, the heavy feedstocks yield less fuel than light petroleum and contain more sulfur and nitrogen. To meet the demands for fuels, a deep understanding of the chemistry of complex fossil-energy feedstocks will be required together with such understanding of how to design catalysts for processing these feedstocks.

The United States has the capacity to grow and convert enough biomass to replace nearly a third of the nation's current gasoline use. Building on catalysis for petroleum conversion, researchers have identified potential catalytic routes for biomass. However, biomass differs so much in composition and reactivity from fossil fuels that this starting point is inadequate. The technology for economically converting biomass into widely usable fuels does not exist, and the science underpinning its development is only now starting to emerge.

The challenge is to understand the chemistry by which cellulose- and lignin-derived molecules are converted to fuels and to use this knowledge as a basis for identifying the needed catalysts. To obtain energy densities similar to those of currently used fuels, the products of biomass conversion must have oxygen contents lower than that of biomass. Oxygen must be removed by using hydrogen derived from biomass or other sources in a manner that minimizes the yield of carbon dioxide as a byproduct.

Catalytic conversion of carbon dioxide into liquid fuels using solar and electrical energy would enable the carbon in carbon dioxide to be recycled into fuels, thereby reducing its contribution to atmospheric warming. Likewise, the catalytic generation of hydrogen from water could provide a carbon-free source of hydrogen for fuel and for processing of fossil and biomass feedstocks. The underlying science is far from sufficient for design of efficient catalysts and economical processes.

Grand Challenges

To realize the full potential of catalysis for energy applications, scientists must develop a profound understanding of catalytic transformations so that they can design and build effective catalysts with atom-by-atom precision and convert reactants to products with molecular precision. Moreover, they must build tools to make real-time, spatially resolved measurements of operating catalysts. Ultimately, scientists must use these tools to achieve a fundamental understanding of catalytic processes occurring in multiscale, multiphase environments.

The first grand challenge identified in this report centers on understanding mechanisms and dynamics of catalyzed reactions. Catalysis involves chemical transformations that must be understood at the atomic scale because catalytic reactions present an intricate dance of chemical bond-breaking and bond-forming steps. Structures of solid catalyst surfaces, where the reactions occur on only a few isolated sites and in the presence of highly complex mixtures of molecules interacting with the surface in myriad ways, are extremely difficult to describe.

To discover new knowledge about mechanisms and dynamics of catalyzed reactions, scientists need to image surfaces at the atomic scale and probe the structures and energetics of the reacting molecules on varying time and length scales. They also need to apply theory to validate the results.

The difficulties of developing a clear understanding of the mechanisms and dynamics of catalyzed reactions are magnified by the high temperatures and pressures at which the reactions occur and the influence of the molecules undergoing transformation on the catalyst. The catalyst structure changes as the reacting molecules become part of it en route to forming products. Although the scientific challenge of understanding catalyst structure and function is great, recent advances in characterization science and facilities provide the means for meeting it in the long term.

The second grand challenge in the report centers on design and controlled synthesis of catalyst structures. Fundamental investigations of catalyst structures and the mechanisms of catalytic reactions provide the necessary foundation for the synthesis of improved catalysts. Theory can serve as a predictive design tool, guiding synthetic approaches for construction of materials with precisely designed catalytic surface structures at the nano and atomic scales.

Success in the design and controlled synthesis of catalytic structures requires an interplay between (1) characterization of catalysts as they function, including evaluation of their performance under technologically realistic conditions, and (2) synthesis of catalyst structures to achieve high activity and product selectivity.

Priority Research Directions

The workshop process identified three priority research directions for advancing catalysis science for energy applications:

Advanced catalysts for the conversion of heavy fossil energy feedstocks

The depletion of light, sweet crude oil has caused increasing use of heavy oils and other heavy feedstocks. The complicated nature of the molecules in these feedstocks, as well as their high heteroatom contents, requires catalysts and processing routes entirely different from those used in today's petroleum refineries.

To advance catalytic technologies for converting heavy feedstocks, scientists must (1) identify and quantify the heavy molecules (now possible with methods such as high-resolution mass spectrometry) and (2) determine data to represent the reactivities of the molecules in the presence of the countless other kinds of molecules interacting with the catalysts.

Methods for determining reactivities of individual compounds within complex feedstocks reacting under industrial conditions soon will be available. Reactivity data, when combined with fundamental understanding of how the reactants interact with the catalysts, will facilitate the selection of new catalysts for heavy feedstocks and the prediction of properties of the fuels produced.

Understanding the chemistry of lignocellulosic biomass deconstruction and conversion to fuels

The United States potentially could harvest 1.3 billion tons of biomass annually. Converting this resource to ethanol would produce more than 60 billion gallons/year, enough to replace 30 percent of the nation's current gasoline use.

Scientists must develop fundamental understanding of biomass deconstruction, either through high-temperature pyrolysis or low-temperature catalytic conversion, before engineers can create commercial biomass conversion technologies. Pyrolysis generates gases and liquids for processing into fuels or blending with existing petroleum refinery streams. Low-temperature deconstruction produces sugars and lignin for conversion into molecules with higher energy densities than the parent biomass.

Scientists also must discover and develop new catalysts for targeted transformations of these biomass-derived molecules into fuels. Developing a molecular-scale understanding of deconstruction and conversion of biomass products to fuels would contribute to the development of optimal processes for particular biomass sources. Knowledge of how catalyst structure and composition affect the kinetics of individual processes could lead to new catalysts with properties adjusted for maximum activity and selectivity for high- and low-temperature processing of biomass.

Photo- and electro-driven conversions of carbon dioxide and water

Catalytic conversion of carbon dioxide to liquid fuels facilitated by the input of solar or electrical energy presents an immense opportunity for new sources of energy. Furthermore, the catalytic generation of hydrogen from water could provide a carbon-free source of hydrogen for fuel and for processing of fossil and biomass feedstocks. Although these electrolytic processes are possible, they are not now economical, because they depend on expensive and rare materials, such as platinum, and require significantly more energy than the minimum dictated by thermodynamics.

Scientists have explored the use of photons to drive thermodynamically uphill reactions, but the efficiencies of the best-known processes are very low. To dramatically increase efficiencies, we need to understand the elementary processes by which photocatalysts and electrocatalysts operate and the phenomena that limit their effectiveness. This knowledge would guide the search for more efficient catalysts.

To address the challenge of increased efficiency, scientists must develop fundamental understanding on the basis of novel spectroscopic methods to probe the surfaces of photocatalysts and electrocatalysts in the presence of liquid electrolytes. New catalysts will have to involve multiple-site structures and be able to drive the multiple-electron and hydrogen transfer reactions required to produce fuels from carbon dioxide and water. Theoretical investigations also are needed to understand the manifold processes occurring on photocatalysts and electrocatalysts, many of which are unique to the conditions of their use. Basic research to address these challenges will result in fundamental knowledge and expertise crucial for developing efficient, durable, and scalable catalysts.

Crosscutting Research Issues

Two broad issues cut across the grand challenges and the priority research directions for development of efficient, economical, and environmentally friendly catalytic processes for energy applications:

Experimental characterization of catalystsas they function is a theme common to all the processes mentioned here—ranging from heavy feedstock refining to carbon dioxide conversion to fuels. The scientific community needs a fundamental understanding of catalyst structures and catalytic reaction mechanisms to design and prepare improved catalysts and processes for energy conversion. Attainment of this understanding requires development of new techniques and facilities for investigating catalysts as they function in the presence of complex, real feedstocks at high temperatures and pressures.

The community also needs improved methods for characterizing the feedstocks and products—to the point of identifying individual compounds in these complex mixtures. The dearth of information characterizing biomass-derived feedstocks and the growing complexity of the available heavy fossil feedstocks, as well as the intrinsic complexity of catalyst surfaces, magnify the difficulty of this challenge.

Implied in the need for better characterization is the need for advanced methods and instrument hardware and software far beyond today's capabilities. Improved spectroscopic and microscopic capabilities, specifically including synchrotron-based equipment and methods, will provide significantly enhanced temporal, spatial, and energy resolution of catalysts and new opportunities for elucidating their performance under realistic reaction conditions.

Achieving these crosscutting goals for better catalyst characterization will require breakthrough developments in techniques and much improved methodologies for combining multiple complementary techniques.

Advances in theory and computation are also required to significantly advance catalysis for energy applications. A major challenge is to understand the mechanisms and dynamics of catalyzed transformations, enabling rational design of catalysts. Molecular-level understanding is essential to "tune" a catalyst to produce the right products with minimal energy consumption and environmental impact. Applications of computational chemistry and methods derived from advanced chemical theory are crucial to the development of fundamental understanding of catalytic processes and ultimately to first-principles catalyst design. Development of this understanding requires breakthroughs in theoretical and computational methods to allow treatment of the complexity of the molecular reactants and condensed-phase and interfacial catalysts needed to convert new energy feedstocks to useful products.

Computation, when combined with advanced experimental techniques, is already leading to broad new insights into catalyst behavior and the design of new materials. The development of new theories and computational tools that accurately predict thermodynamic properties, dynamical behavior, and coupled kinetics of complex condensed-phase and interfacial processes is a crosscutting priority research direction to address the grand challenges of catalysis science, especially in the area of advanced energy technologies.

Scientific and Technological Impact

The urgent need for fuels in an era of declining resources and pressing environmental concerns demands a resurgence in catalysis science, requiring a massive commitment of programmatic leadership and improved experimental and theoretical methods. These elements will make it possible to follow, in real time, catalytic reactions on an atomic scale on surfaces that are nonuniform and laden with large molecules undergoing complex competing processes. The understanding that will emerge promises to engender technology for economical catalytic processing of ever more challenging fossil feedstocks and for breakthroughs needed to create an industry for energy production from biomass. These new technologies are needed for a sustainable supply of energy from domestic sources and mitigation of the problem of greenhouse gas emissions.

JPG
Report
Report

Future Science Needs and Opportunities for Electron Scattering: Next-Generation Instrumentation and Beyond

This report is based on a BES Workshop entitled "Future Science Needs and Opportunities for Electron Scattering: Next-Generation Instrumentation and Beyond," March 1-2, 2007, to identify emerging basic science and engineering research needs and opportunities that will require major advances in electron-scattering theory, technology, and instrumentation.

The workshop was organized to help define the scientific context and strategic priorities for the U.S. Department of Energy's Office of Basic Energy Sciences (DOE-BES) electron-scattering development for materials characterization over the next decade and beyond. Attendees represented university, national laboratory, and commercial research organizations from the United States and around the world. The workshop comprised plenary sessions, breakout groups, and joint open discussion summary sessions. Complete information about this workshop is available at http://www.amc.anl.gov/DoE-ElectronScatteringWorkshop-2007

SCIENTIFIC CHALLENGES FACING THE CHARACTERIZATION OF MATERIALS

In the last 40 years, advances in instrumentation have gradually increased the resolution capabilities of commercial electron microscopes. Within the last decade, however, a revolution has occurred, facilitating 1-nm resolution in the scanning electron microscope and sub-Ångstrom resolution in the transmission electron microscope. This revolution was a direct result of decades-long research efforts concentrating on electron optics, both theoretically and in practice, leading to implementation of aberration correctors that employ multi-pole electron lenses. While this improvement has been a remarkable achievement, it has also inspired the scientific community to ask what other capabilities are required beyond "image resolution" to more fully address the scientific problems of today's technologically complex materials. During this workshop, a number of scientific challenges requiring breakthroughs in electron scattering and/or instrumentation for characterization of materials were identified. Although the individual scientific problems identified in the workshop were wide-ranging, they are well represented by seven major scientific challenges. These are listed in Table 1, together with their associated application areas as proposed by workshop attendees. Addressing these challenges will require dedicated long-term developmental efforts similar to those that have been applied to the electron optics revolution. This report summarizes the scientific challenges identified by attendees and then outlines the technological issues that need to be addressed by a long-term research and development (R&D) effort to overcome these challenges.

TECHNOLOGICAL CHALLENGES

A recurring message voiced during the meeting was that, while improved image resolution in commercially available tools is significant, this is only the first of many breakthroughs required to answer today's most challenging problems. The major technological issues that were identified, as well as a measure of their relative priority, appear in Table 2. These issues require not only the development of innovative instrumentation but also new analytical procedures that connect experiment, theory, and modeling.

Table 1 Scientific Challenges and Applications Areas Identified during the Workshop

Theme	Application Area
1. The nanoscale origin of macroscopic properties	High-performance 21st century materials in both structural engineering and electronic applications
2. The role of individual atoms, point defects, and dopants in materials	Semiconductors, catalysts, quantum phenomena and confinement, fracture, embrittlement, solar energy, nuclear power, radiation damage
3. Characterization of interfaces at arbitrary orientations	Semiconductors, three-dimensional geometries for nanostructures, grain-boundary-dominated processes, hydrogen storage
4. The interface between ordered and disordered materials	Dynamic behavior of the liquid-solid interface, organic/inorganic interfaces, friction/wear, grain boundaries, welding, polymer/metal/oxide composites, self-assembly
5. Mapping of electromagnetic (EM) fields in and around nanoscale matter	Ferroelectric/magnetic structures, switching, tunneling and transport, quantum confinement/proximity, superconductivity
6. Probing structures in their native environments	Catalysis, fuel cells, organic/inorganic interfaces, functionalized nanoparticles for health care, polymers, biomolecular processes, biomaterials, soft-condensed matter, non-vacuum environments
7. The behavior of matter far from equilibrium	High radiation, high-pressure and high-temperature environments, dynamic/transient behavior, nuclear and fusion energy, outer space, nucleation, growth and synthesis in solution, corrosion, phase transformations

Table 2 Functionality Required to Address Challenges in Table 1

Functionality Required	Priority
1	In-situ environments permitting observation of processes under conditions that replicate real-world/real-time conditions (temperature, pressure, atmosphere, EM fields, fluids) with minimal loss of image and/or spectral resolution	A
2	Detectors that enhance by more than an order of magnitude the temporal, spatial, and/or collection efficiency of existing technologies for electrons, photons, and/or X-rays	A
3	Higher temporal resolution instruments for dynamic studies with a continuous range of operating conditions from microseconds to femtoseconds A 4. Sources having higher brightness, temporal resolution, and polarization	A
4	Sources having higher brightness, temporal resolution, and polarization	B
5	Electron-optical configurations designed to study complex interactions of nanoscale objects under multiple excitation processes (photons, fields, …)	B
6	Virtualized instruments that are operating in connection with experimental tools, allowing real-time data quantitative analysis or simulation, and community software tools for routine and robust data analysis	C

Some research efforts have already begun to address these topics. However, a dedicated and coordinated approach is needed to address these challenges more rapidly. For example, the principles of aberration correction for electron-optical lenses were established theoretically by Scherzer (Zeitschrift für Physik 101(9-10), 593-603) in 1936, but practical implementation was not realized until 1997 (a 61-year development cycle). Reducing development time to less than a decade is essential in addressing the scientific issues in the ever-growing nanoscale materials world. To accomplish this, DOE should make a concerted effort to revise how it funds advanced resources and R&D for electron beam instrumentation across its programs.

JPG
Report
Report

Basic Research Needs for Electrical Energy Storage

This report is based on a BES Workshop on Basic Research Needs for Electrical Energy Storage (EES), April 2-4, 2007, to identify basic research needs and opportunities underlying batteries, capacitors, and related EES technologies, with a focus on new or emerging science challenges with potential for significant long-term impact on the efficient storage and release of electrical energy.

The projected doubling of world energy consumption within the next 50 years, coupled with the growing demand for low- or even zero-emission sources of energy, has brought increasing awareness of the need for efficient, clean, and renewable energy sources. Energy based on electricity that can be generated from renewable sources, such as solar or wind, offers enormous potential for meeting future energy demands. However, the use of electricity generated from these intermittent, renewable sources requires efficient electrical energy storage. For commercial and residential grid applications, electricity must be reliably available 24 hours a day; even second-to-second fluctuations cause major disruptions with costs estimated to be tens of billions of dollars annually. Thus, for large-scale solar- or wind-based electrical generation to be practical, the development of new EES systems will be critical to meeting continuous energy demands and effectively leveling the cyclic nature of these energy sources. In addition, greatly improved EES systems are needed to progress from today's hybrid electric vehicles to plug-in hybrids or all-electric vehicles. Improvements in EES reliability and safety are also needed to prevent premature, and sometimes catastrophic, device failure. Chemical energy storage devices (batteries) and electrochemical capacitors (ECs) are among the leading EES technologies today. Both are based on electrochemistry, and the fundamental difference between them is that batteries store energy in chemical reactants capable of generating charge, whereas electrochemical capacitors store energy directly as charge.

The performance of current EES technologies falls well short of requirements for using electrical energy efficiently in transportation, commercial, and residential applications. For example, EES devices with substantially higher energy and power densities and faster recharge times are needed if all-electric/plug-in hybrid vehicles are to be deployed broadly as replacements for gasoline-powered vehicles. Although EES devices have been available for many decades, there are many fundamental gaps in understanding the atomic- and molecular-level processes that govern their operation, performance limitations, and failure. Fundamental research is critically needed to uncover the underlying principles that govern these complex and interrelated processes. With a full understanding of these processes, new concepts can be formulated for addressing present EES technology gaps and meeting future energy storage requirements.

BES worked closely with the DOE Office of Energy Efficiency and Renewable Energy and the DOE Office of Electricity Delivery and Energy Reliability to clearly define future requirements for EES from the perspective of applications relevant to transportation and electricity distribution, respectively, and to identify critical technology gaps. In addition, leaders in EES industrial and applied research laboratories were recruited to prepare a technology resource document, Technology and Applied R&D Needs for Electrical Energy Storage, which provided the groundwork for and served as a basis to inform the deliberation of basic research discussions for the workshop attendees. The invited workshop attendees, numbering more than 130, included representatives from universities, national laboratories, and industry, including a significant number of scientists from Japan and Europe. A plenary session at the beginning of the workshop captured the present state of the art in research and development and technology needs required for EES for the future. The workshop participants were asked to identify key priority research directions that hold particular promise for providing needed advances that will, in turn, revolutionize the performance of EES. Participants were divided between two panels focusing on the major types of EES, chemical energy storage and capacitive energy storage. A third panel focused on cross-cutting research that will be critical to achieving the technical breakthroughs required to meet future EES needs. A closing plenary session summarized the most urgent research needs that were identified for both chemical and capacitive energy storage. The research directions identified by the panelists are presented in this report in three sections corresponding to the findings of the three workshop panels.

The panel on chemical energy storage acknowledged that progressing to the higher energy and power densities required for future batteries will push materials to the edge of stability; yet these devices must be safe and reliable through thousands of rapid charge-discharge cycles. A major challenge for chemical energy storage is developing the ability to store more energy while maintaining stable electrode-electrolyte interfaces. The need to mitigate the volume and structural changes to the active electrode sites accompanying the charge-discharge cycle encourages exploration of nanoscale structures. Recent developments in nanostructured and multifunctional materials were singled out as having the potential to dramatically increase energy capacity and power densities. However, an understanding of nanoscale phenomena is needed to take full advantage of the unique chemistry and physics that can occur at the nanoscale. Further, there is an urgent need to develop a fundamental understanding of the interdependence of the electrolyte and electrode materials, especially with respect to controlling charge transfer from the electrode to the electrolyte. Combining the power of new computational capabilities and in situ analytical tools could open up entirely new avenues for designing novel multifunctional nanomaterials with the desired physical and chemical properties, leading to greatly enhanced performance.

The panel on capacitive storage recognized that, in general, ECs have higher power densities than batteries, as well as sub-second response times. However, energy storage densities are currently lower than they are for batteries and are insufficient for many applications. As with batteries, the need for higher energy densities requires new materials. Similarly, advances in electrolytes are needed to increase voltage and conductivity while ensuring stability. Understanding how materials store and transport charge at electrode-electrolyte interfaces is critically important and will require a fundamental understanding of charge transfer and transport mechanisms. The capability to synthesize nanostructured electrodes with tailored, high-surface-area architectures offers the potential for storing multiple charges at a single site, increasing charge density. The addition of surface functionalities could also contribute to high and reproducible charge storage capabilities, as well as rapid charge-discharge functions. The design of new materials with tailored architectures optimized for effective capacitive charge storage will be catalyzed by new computational and analytical tools that can provide the needed foundation for the rational design of these multifunctional materials. These tools will also provide the molecular-level insights required to establish the physical and chemical criteria for attaining higher voltages, higher ionic conductivity, and wide electrochemical and thermal stability in electrolytes.

The third panel identified four cross-cutting research directions that were considered to be critical for meeting future technology needs in EES:

Advances in Characterization
Nanostructured Materials
Innovations in Electrolytes
Theory, Modeling, and Simulation

Exceptional insight into the physical and chemical phenomena that underlie the operation of energy storage devices can be afforded by a new generation of analytical tools. This information will catalyze the development of new materials and processes required for future EES systems. New in situ photon- and particle-based microscopic, spectroscopic, and scattering techniques with time resolution down to the femtosecond range and spatial resolution spanning the atomic and mesoscopic scales are needed to meet the challenge of developing future EES systems. These measurements are critical to achieving the ability to design EES systems rationally, including materials and novel architectures that exhibit optimal performance. This information will help identify the underlying reasons behind failure modes and afford directions for mitigating them.

The performance of energy storage systems is limited by the performance of the constituent materials—including active materials, conductors, and inert additives. Recent research suggests that synthetic control of material architectures (including pore size, structure, and composition; particle size and composition; and electrode structure down to nanoscale dimensions) could lead to transformational breakthroughs in key energy storage parameters such as capacity, power, charge-discharge rates, and lifetimes. Investigation of model systems of irreducible complexity will require the close coupling of theory and experiment in conjunction with well-defined structures to elucidate fundamental materials properties. Novel approaches are needed to develop multifunctional materials that are self-healing, self-regulating, failure-tolerant, impurity-sequestering, and sustainable. Advances in nanoscience offer particularly exciting possibilities for the development of revolutionary three-dimensional architectures that simultaneously optimize ion and electron transport and capacity.

The design of EES systems with long cycle lifetimes and high energy-storage capacities will require a fundamental understanding of charge transfer and transport processes. The interfaces of electrodes with electrolytes are astonishingly complex and dynamic. The dynamic structures of interfaces need to be characterized so that the paths of electrons and attendant trafficking of ions may be directed with exquisite fidelity. New capabilities are needed to "observe" the dynamic composition and structure at an electrode surface, in real time, during charge transport and transfer processes. With this underpinning knowledge, wholly new concepts in materials design can be developed for producing materials that are capable of storing higher energy densities and have long cycle lifetimes.

A characteristic common to chemical and capacitive energy storage devices is that the electrolyte transfers ions/charge between electrodes during charge and discharge cycles. An ideal electrolyte provides high conductivity over a broad temperature range, is chemically and electrochemically inert at the electrode, and is inherently safe. Too often the electrolyte is the weak link in the energy storage system, limiting both performance and reliability of EES. At present, the myriad interactions that occur in electrolyte systems—ion-ion, ion-solvent, and ion-electrode—are poorly understood. Fundamental research will provide the knowledge that will permit the formulation of novel designed electrolytes, such as ionic liquids and nanocomposite polymer electrolytes, that will enhance the performance and lifetimes of electrolytes.

Advances in fundamental theoretical methodologies and computer technologies provide an unparalleled opportunity for understanding the complexities of processes and materials needed to make the groundbreaking discoveries that will lead to the next generation of EES. Theory, modeling, and simulation can effectively complement experimental efforts and can provide insight into mechanisms, predict trends, identify new materials, and guide experiments. Large multiscale computations that integrate methods at different time and length scales have the potential to provide a fundamental understanding of processes such as phase transitions in electrode materials, ion transport in electrolytes, charge transfer at interfaces, and electronic transport in electrodes.

Revolutionary breakthroughs in EES have been singled out as perhaps the most crucial need for this nation's secure energy future. The BES Workshop on Basic Research Needs for Electrical Energy Storage concluded that the breakthroughs required for tomorrow's energy storage needs will not be realized with incremental evolutionary improvements in existing technologies. Rather, they will be realized only with fundamental research to understand the underlying processes involved in EES, which will in turn enable the development of novel EES concepts that incorporate revolutionary new materials and chemical processes. Recent advances have provided the ability to synthesize novel nanoscale materials with architectures tailored for specific performance; to characterize materials and dynamic chemical processes at the atomic and molecular level; and to simulate and predict structural and functional relationships using modern computational tools. Together, these new capabilities provide unprecedented potential for addressing technology and performance gaps in EES devices.

JPG
Report

Basic Research Needs for Geosciences: Facilitating 21st Century Energy Systems

This report is based on a BES Workshop on Basic Research Needs for Geosciences: Facilitating 21st Century Energy Systems, February 21-23, 2007, to identify research areas in geosciences, such as behavior of multiphase fluid-solid systems on a variety of scales, chemical migration processes in geologic media, characterization of geologic systems, and modeling and simulation of geologic systems, needed for improved energy systems.

Serious challenges must be faced in this century as the world seeks to meet global energy needs and at the same time reduce emissions of greenhouse gases to the atmosphere. Even with a growing energy supply from alternative sources, fossil carbon resources will remain in heavy use and will generate large volumes of carbon dioxide (CO₂). To reduce the atmospheric impact of this fossil energy use, it is necessary to capture and sequester a substantial fraction of the produced CO₂. Subsurface geologic formations offer a potential location for long-term storage of the requisite large volumes of CO₂. Nuclear energy resources could also reduce use of carbon-based fuels and CO₂ generation, especially if nuclear energy capacity is greatly increased. Nuclear power generation results in spent nuclear fuel and other radioactive materials that also must be sequestered underground. Hence, regardless of technology choices, there will be major increases in the demand to store materials underground in large quantities, for long times, and with increasing efficiency and safety margins.

Rock formations are composed of complex natural materials and were not designed by nature as storage vaults. If new energy technologies are to be developed in a timely fashion while ensuring public safety, fundamental improvements are needed in our understanding of how these rock formations will perform as storage systems.

This report describes the scientific challenges associated with geologic sequestration of large volumes of carbon dioxide for hundreds of years, and also addresses the geoscientific aspects of safely storing nuclear waste materials for thousands to hundreds of thousands of years. The fundamental crosscutting challenge is to understand the properties and processes associated with complex and heterogeneous subsurface mineral assemblages comprising porous rock formations, and the equally complex fluids that may reside within and flow through those formations. The relevant physical and chemical interactions occur on spatial scales that range from those of atoms, molecules, and mineral surfaces, up to tens of kilometers, and time scales that range from picoseconds to millennia and longer. To predict with confidence the transport and fate of either CO₂ or the various components of stored nuclear materials, we need to learn to better describe fundamental atomic, molecular, and biological processes, and to translate those microscale descriptions into macroscopic properties of materials and fluids. We also need fundamental advances in the ability to simulate multiscale systems as they are perturbed during sequestration activities and for very long times afterward, and to monitor those systems in real time with increasing spatial and temporal resolution. The ultimate objective is to predict accurately the performance of the subsurface fluid-rock storage systems, and to verify enough of the predicted performance with direct observations to build confidence that the systems will meet their design targets as well as environmental protection goals.

The report summarizes the results and conclusions of a Workshop on Basic Research Needs for Geosciences held in February 2007. Five panels met, resulting in four Panel Reports, three Grand Challenges, six Priority Research Directions, and three Crosscutting Research Issues. The Grand Challenges differ from the Priority Research Directions in that the former describe broader, long-term objectives while the latter are more focused.

GRAND CHALLENGES

Computational thermodynamics of complex fluids and solids. Predictions of geochemical transport in natural materials must start with detailed knowledge of the chemical properties of multicomponent fluids and solids. New modeling strategies for geochemical systems based on first-principles methods are required, as well as reliable tools for translating atomic-and molecular-scale descriptions to the many orders of magnitude larger scales of subsurface geologic systems. Specific challenges include calculation of equilibrium constants and kinetics of heterogeneous reactions, descriptions of adsorption and other mineral surface processes, properties of transuranic elements and compounds, and mixing and transport properties for multicomponent liquid, solid and supercritical solutions. Significant advances are required in calculations based on the electronic Schrödinger equation, scaling of solution methods, and representation in terms of Equations of State. Calibration of models with a new generation of experiments will be critical.

Integrated characterization, modeling, and monitoring of geologic systems. Characterization of the subsurface is inextricably linked to the modeling and monitoring of processes occurring there. More accurate descriptions of the behavior of subsurface storage systems will require that the diverse, independent approaches currently used for characterizing, modeling and monitoring be linked in a revolutionary and comprehensive way and carried out simultaneously. The challenges arise from the inaccessibility and complexity of the subsurface, the wide range of scales of variability, and the potential role of coupled nonlinear processes. Progress in subsurface simulation requires advances in the application of geological process knowledge for determining model structure and the effective integration of geochemical and high-resolution geophysical measurements into model development and parameterization. To fully integrate characterization and modeling will require advances in methods for joint inversion of coupled process models that effectively represent nonlinearities, scale effects, and uncertainties.

Simulation of multiscale geologic systems for ultra-long times. Anthropogenic perturbations of subsurface storage systems will occur over decades, but predictions of storage performance will be needed that span hundreds to many thousands of years, time scales that reach far beyond standard engineering practice. Achieving this simulation capability requires a major advance in modeling capability that will accurately couple information across scales, i.e., account for the effects of small-scale processes on larger scales, and the effects of fast processes as well as the ultra-slow evolution on long time scales. Cross-scale modeling of complex dynamic subsurface systems requires the development of new computational and numerical methods of stochastic systems, new multiscale formulations, data integration, improvements in inverse theory, and new methods for optimization.

PRIORITY RESEARCH DIRECTIONS

Mineral-water interface complexity and dynamics. Natural materials are structurally complex, with variable composition, roughness, defect content, and organic and mineral coatings. There is an overarching need to interrogate the complex structure and dynamics at mineral-water interfaces with increasing spatial and temporal resolution using existing and emerging experimental and computational approaches. The fundamental objectives are to translate a molecular-scale description of complex mineral surfaces to thermodynamic quantities for the purpose of linking with macroscopic models, to follow interfacial reactions in real time, and to understand how minerals grow and dissolve and how the mechanisms couple dynamically to changes at the interface.

Nanoparticulate and colloid chemistry and physics. Colloidal particles play critical roles in dispersion of contaminants from energy production, use, or waste isolation sites. New advances are needed in characterization of colloids, sampling technologies, and conceptual models for reactivity, fate, and transport of colloidal particles in aqueous environments. Specific advances will be needed in experimental techniques to characterize colloids at the atomic level and to build quantitative models of their properties and reactivity.

Dynamic imaging of flow and transport. Improved imaging in the subsurface is needed to allow in situ multiscale measurement of state variables as well as flow, transport, fluid age, and reaction rates. Specific research needs include development of smart tracers, identification of environmental tracers that would allow age dating fluids in the 50-3000 year range, methods for measuring state variables such as pressure and temperature continuously in space and time, and better models for the interactions of physical fields, elastic waves, or electromagnetic perturbations with fluid-filled porous media.

Transport properties and in situ characterization of fluid trapping, isolation, and immobilization. Mechanisms of immobilization of injected CO₂ include buoyancy trapping of fluids by geologic seals, capillary trapping of fluid phases as isolated bubbles within rock pores, and sorption of CO₂ or radionuclides on solid surfaces. Specific advances will be needed in our ability to understand and represent the interplay of interfacial tension, surface properties, buoyancy, the state of stress, and rock heterogeneity in the subsurface.

Fluid-induced rock deformation. CO₂ injection affects the thermal, mechanical, hydrological, and chemical state of large volumes of the subsurface. Accurate forecasting of the effects requires improved understanding of the coupled stress-strain and flow response to injection-induced pressure and hydrologic perturbations in multiphase-fluid saturated systems. Such effects manifest themselves as changes in rock properties at the centimeter scale, mechanical deformation at meter-to-kilometer scales, and modified regional fluid flow at scales up to 100 km. Predicting the hydromechanical properties of rocks over this scale range requires improved models for the coupling of chemical, mechanical, and hydrological effects. Such models could revolutionize our ability to understand shallow crustal deformation related to many other natural processes and engineering applications.

Biogeochemistry in extreme subsurface environments. Microorganisms strongly influence the mineralogy and chemistry of geologic systems. CO₂ and nuclear material isolation will perturb the environments for these microorganisms significantly. Major advances are needed to describe how populations of microbes will respond to the extreme environments of temperature, pH, radiation, and chemistry that will be created, so that a much clearer picture of biogenic products, potential for corrosion, and transport or immobilization of contaminants can be assembled.

CROSSCUTTING RESEARCH ISSUES

The microscopic basis of macroscopic complexity. Classical continuum mechanics relies on the assumption of a separation between the length scales of microscopic fluctuations and macroscopic motions. However, in geologic problems this scale separation often does not exist. There are instead fluctuations at all scales, and the resulting macroscopic behavior can then be quite complex. The essential need is to develop a scientific basis of "emergent" phenomena based on the microscopic phenomena.

Highly reactive subsurface materials and environments. The emplacement of energy system byproducts into geological repositories perturbs temperature and pressure, imposes chemical gradients, creates intense radiation fields, and can cause reactions that alter the minerals, pore fluids, and emplaced materials. Strong interactions between the geochemical environment and emplaced materials are expected. New insight is needed on equilibria in compositionally complex systems, reaction kinetics in concentrated aqueous and other solutions, reaction kinetics under near-equilibrium undersaturated and supersaturated conditions, and transient reaction kinetics.

Thermodynamics of the solute-to-solid continuum. Reactions involving solutes, colloids, particles, and surfaces control the transport of chemical constituents in the subsurface environment. A rigorous structural, kinetic, and thermodynamic description of the complex chemical reality between the molecular and the macroscopic scale is a fundamental scientific challenge. Advanced techniques are needed for characterizing particles in the nanometer-tomicrometer size range, combined with a new description of chemical thermodynamics that does not rely on a sharp distinction between solutes and solids.

TECHNICAL AND SCIENTIFIC IMPACT

The Grand Challenges, Priority Research Directions, and Crosscutting Issues described in this report define a science-based approach to understanding the long-term behavior of subsurface geologic systems in which anthropogenic CO₂ and nuclear materials could be stored. The research areas are rich with opportunities to build fundamental knowledge of the physics, chemistry, and materials science of geologic systems that will have impacts well beyond the specific applications. The proposed research is based on development of a new level of understanding—physical, chemical, biological, mathematical, and computational—of processes that happen at the microscopic scale of atoms, molecules and mineral surfaces, and how those processes translate to material behavior over large length scales and on ultra-long time scales. Addressing the basic science issues described would revolutionize our ability to understand, simulate, and monitor all of the subsurface settings in which transport is critical, including the movement of contaminants, the emplacement of minerals, or the management of aquifers. The results of the research will have a wide range of implications from physics and chemistry, to material science, biology and earth science.

JPG
Report

Basic Research Needs for Clean and Efficient Combustion of 21st Century Transportation Fuels

This report is based on a BES Workshop on Clean and Efficient Combustion of 21st Century Transportation Fuels, October 29-November 1, 2006, to identify basic research needs and opportunities underlying utilization of evolving transportation fuels, with a focus on new or emerging science challenges that have the potential for significant long-term impact on fuel efficiency and emissions.

From the invention of the wheel, advances in transportation have increased the mobility of human kind, enhancing the quality of life and altering our very perception of time and distance. Early carts and wagons driven by human or animal power allowed the movement of people and goods in quantities previously thought impossible. With the rise of steam power, propeller driven ships and railroad locomotives shrank the world as never before. Ocean crossings were no longer at the whim of the winds, and continental crossings went from grand adventures to routine, scheduled outings. The commercialization of the internal combustion engine at the turn of the twentieth century brought about a new, and very personal, revolution in transportation, particularly in the United States. Automobiles created an unbelievable freedom of movement: A single person could travel to any point in the county in a matter of days, on a schedule of his or her own choosing. Suburbs were built on the promise of cheap, reliable, personal transportation. American industry grew to depend on internal combustion engines to produce and transport goods, and farmers increased yields and efficiency by employing farm machinery. Airplanes, powered by internal combustion engines, shrank the world to the point where a trip between almost any two points on the globe is now measured not in days or months, but in hours.

Transportation is the second largest consumer of energy in the United States, accounting for nearly 60% of our nation's use of petroleum, an amount equivalent to all of the oil imported into the U.S. The numbers are staggering—the transport of people and goods within the U.S. burns almost one million gallons of petroleum each minute of the day. Our Founding Fathers may not have foreseen freedom of movement as an inalienable right, but Americans now view it as such.

Knowledge is power, a maxim that is literally true for combustion. In our global, just-in-time economy, American competitiveness and innovation require an affordable, diverse, stable, and environmentally acceptable energy supply. Currently 85% of our nation's energy comes from hydrocarbon sources, including natural gas, petroleum, and coal; 97% of transportation energy derives from petroleum, essentially all from combustion in gasoline engines (65%), diesel engines (20%), and jet turbines (12%). The monolithic nature of transportation technologies offers the opportunity for improvements in efficiency of 25-50% through strategic technical investment in advanced fuel/engine concepts and devices. This investment is not a matter of choice, but, an economic, geopolitical, and environmental necessity. The reality is that the internal combustion engine will remain the primary driver of transport for the next 30-50 years, whether or not one believes that the peak in oil is past or imminent, or that hydrogen-fueled and electric vehicles will power transport in the future, or that geopolitical tensions will ease through international cooperation. Rational evaluation of U.S. energy security must include careful examination of how we achieve optimally efficient and clean combustion of precious transportation fuels in the 21^st century.

The Basic Energy Sciences Workshop on Clean and Efficient Combustion of 21^st Century Transportation Fuels

Our historic dependence on light, sweet crude oil for our transportation fuels will draw to a close over the coming decades as finite resources are exhausted. New fuel sources, with differing characteristics, are emerging to displace crude oil. As these new fuel streams enter the market, a series of new engine technologies are also under development, promising improved efficiency and cleaner combustion. To date, however, a coordinated strategic effort to match future fuels with evolving engines is lacking.

To provide the scientific foundation to enable technology breakthroughs in transportation fuel utilization, the Office of Basic Energy Sciences in the U.S. Department of Energy (DOE) convened the Workshop on Basic Research Needs for Clean and Efficient Combustion of 21^st Century Transportation Fuels from October 30 to November 1, 2006. This report is a summary of that Workshop. It reflects the collective output of the Workshop participants, which included over 80 leading scientists and engineers representing academia, industry, and national laboratories in the United States and Europe. Researchers specializing in basic science and technological applications were well represented, producing a stimulating and engaging forum. Workshop planning and execution involved advance coordination with DOE Office of Energy Efficiency and Renewable Energy, FreedomCAR and Vehicle Technologies, which manages applied research and development of transportation technologies.

Priority research directions were identified by three panels, each made up of a subset of the Workshop attendees and interested observers. The first two panels were differentiated by their focus on engines or fuels and were similar in their strategy of working backward from technology drivers to scientific research needs. The first panel focused on Novel Combustion, as embodied in promising new engine technologies. The second panel focused on Fuel Utilization, inspired by the unique (and largely unknown) challenges of the emerging fuel streams entering the market. The third panel explored crosscutting science themes and identified general gaps in our scientific understanding of 21^st-century fuel combustion. Subsequent to the Workshop, co-chairs and panel leads distilled the collective output to produce eight distinct, targeted research areas that advance one overarching grand challenge: to develop a validated, predictive, multi-scale, combustion modeling capability to optimize the design and operation of evolving fuels in advanced engines for transportation applications.

Fuels and Engines

Transportation fuels for automobile, truck and aircraft engines are currently produced by refining petroleum-based sweet crude oil, from which gasoline, diesel fuel and jet fuel are each made with specific physical and chemical characteristics dictated by the type of engine in which they are to be burned. Standardized fuel properties and restricted engine operating domains couple to provide reliable performance. As new fuels derived from oil sands, oil shale, coal, and bio-feedstocks emerge as replacements for light, sweet crude oil, both uncertainties and strategic opportunities arise. Rather than pursue energy-intensive refining of these qualitatively different emerging fuels to match current fuel formulations, we must strive to achieve a "dual revolution" by interdependently advancing both fuel and engine technologies. Spark-ignited gasoline engines equipped with catalytic after-treatment operate cleanly but well below optimal efficiency due to low compression ratios and throttle-plate losses used to control air intake. Diesel engines operate more efficiently at higher compression ratios but sample broad realms of fuel/air ratio, thereby producing soot and NO_x for which burnout and/or removal can prove problematic. A number of new engine technologies are attempting to overcome these efficiency and emissions compromises. Direct injection gasoline engines operate without throttle plates, increasing efficiency, while retaining the use of a catalytic converter. Ultra-lean, high-pressure, low-temperature diesel combustion seeks to avoid the conditions that form pollutants, while maintaining very high efficiency. A new form of combustion, homogeneous charge compression ignition (HCCI) seeks to combine the best of diesel and gasoline engines. HCCI employs a premixed fuel-air charge that is ignited by compression, with the ignition timing controlled by in-cylinder fuel chemistry. Each of these advanced combustion strategies must permit and even exploit fuel flexibility as the 21^st-century fuel stream matures. The opportunity presented by new fuel sources and advanced engine concepts offers such an overwhelming design and operation parameter space that only those technologies that build upon a predictive science capability will likely mature to a product within a useful timeframe.

Research Directions

The Workshop identified a single, overarching grand challenge: The development of a validated, predictive, multi-scale, combustion modeling capability to optimize the design and operation of evolving fuels in advanced engines for transportation applications. A broad array of discovery research and scientific inquiry that integrates experiment, theory, modeling and simulation will be required. This predictive capability, if attained, will change fundamentally the process for fuels research and engine development by establishing a scientific understanding of sufficient depth and flexibility to facilitate realistic simulation of fuel combustion in existing and proposed engines. Similar understanding in aeronautics has produced the beautiful and efficient complex curves of modern aircraft wings. These designs could never have been realized through cut-and-try engineering, but rather rely on the prediction and optimization of complex air flows. An analogous experimentally validated, predictive capability for combustion is a daunting challenge for numerous reasons: (1) spatial scales of importance range from the dimensions of the atom up to that of an engine piston; (2) the combustion chemistry of 21^st-century fuels is astonishingly complex with hundreds of different fuel molecules and many thousands of possible reactions contributing to the oxidative release of energy stored in chemical bonds—chemical details also dictate emissions profiles, engine knock conditions and, for HCCI, ignition timing; (3) evolving engine designs will operate under dilute conditions at very high pressures and compression ratios—we possess neither sufficient concepts nor experimental tools to address these new operating conditions; (4) turbulence, transport, and radiative phenomena have a profound impact on local chemistry in most combustion media but are poorly understood and extremely challenging to characterize; (5) even assuming optimistic growth in computing power for existing and envisioned architectures, combustion phenomena are and will remain too complex to simulate in their complete detail, and methods that condense information and accurately propagate uncertainties across length and time scales will be required to optimize fuel/engine design and operation. Eight priority research directions, each of which focuses on crucial elements of the overarching grand challenge, are cited as most critical to the path forward by the Workshop participants.

In addition to the unifying grand challenge and specific priority research directions, the Workshop produced a keen sense of urgency and opportunity for the development of revolutionary combustion technology for transportation based upon fundamental combustion science. Internal combustion engines are often viewed as mature technology, developed in an Edisonian fashion over a hundred years. The participants at the Workshop were unanimous in their view that only through the achievable goal of truly predictive combustion science will the engines of the 21st century realize unparalleled efficiency and cleanliness in the challenging environment of changing fuel streams.

JPG
Report
Report

Basic Research Needs for Advanced Nuclear Energy Systems

This report is based on a BES Workshop on Advanced Nuclear Energy Systems, July 31-August 3, 2006, to identify new, emerging, and scientifically challenging areas in materials and chemical sciences that have the potential for significant impact on advanced nuclear energy systems.

The global utilization of nuclear energy has come a long way from its humble beginnings in the first sustained nuclear reaction at the University of Chicago in 1942. Today, there are over 440 nuclear reactors in 31 countries producing approximately 16% of the electrical energy used worldwide. In the United States, 104 nuclear reactors currently provide 19% of electrical energy used nationally. The International Atomic Energy Agency projects significant growth in the utilization of nuclear power over the next several decades due to increasing demand for energy and environmental concerns related to emissions from fossil plants. There are 28 new nuclear plants currently under construction including 10 in China, 8 in India, and 4 in Russia. In the United States, there have been notifications to the Nuclear Regulatory Commission of intentions to apply for combined construction and operating licenses for 27 new units over the next decade.

The projected growth in nuclear power has focused increasing attention on issues related to the permanent disposal of nuclear waste, the proliferation of nuclear weapons technologies and materials, and the sustainability of a once-through nuclear fuel cycle. In addition, the effective utilization of nuclear power will require continued improvements in nuclear technology, particularly related to safety and efficiency. In all of these areas, the performance of materials and chemical processes under extreme conditions is a limiting factor. The related basic research challenges represent some of the most demanding tests of our fundamental understanding of materials science and chemistry, and they provide significant opportunities for advancing basic science with broad impacts for nuclear reactor materials, fuels, waste forms, and separations techniques. Of particular importance is the role that new nanoscale characterization and computational tools can play in addressing these challenges. These tools, which include DOE synchrotron X-ray sources, neutron sources, nanoscale science research centers, and supercomputers, offer the opportunity to transform and accelerate the fundamental materials and chemical sciences that underpin technology development for advanced nuclear energy systems.

The fundamental challenge is to understand and control chemical and physical phenomena in multi-component systems from femto-seconds to millennia, at temperatures to 1000ºC, and for radiation doses to hundreds of displacements per atom (dpa). This is a scientific challenge of enormous proportions, with broad implications in the materials science and chemistry of complex systems. New understanding is required for microstructural evolution and phase stability under relevant chemical and physical conditions, chemistry and structural evolution at interfaces, chemical behavior of actinide and fission-product solutions, and nuclear and thermo-mechanical phenomena in fuels and waste forms. First-principles approaches are needed to describe f-electron systems, design molecules for separations, and explain materials failure mechanisms. Nanoscale synthesis and characterization methods are needed to understand and design materials and interfaces with radiation, temperature, and corrosion resistance. Dynamical measurements are required to understand fundamental physical and chemical phenomena. New multiscale approaches are needed to integrate this knowledge into accurate models of relevant phenomena and complex systems across multiple length and time scales.

Workshop

The Department of Energy (DOE) Workshop on Basic Research Needs for Advanced Nuclear Energy Systems was convened in July 2006 to identify new, emerging, and scientifically challenging areas in materials and chemical sciences that have the potential for significant impact on advanced nuclear energy systems. Sponsored by the DOE Office of Basic Energy Sciences (BES), the workshop provided recommendations for priority research directions and crosscutting research themes that underpin the development of advanced materials, fuels, waste forms, and separations technologies for the effective utilization of nuclear power. A total of 235 invited experts from 31 universities, 11 national laboratories, 6 industries, 3 government agencies, and 11 foreign countries attended the workshop.

The workshop was the sixth in a series of BES workshops focused on identifying basic research needs to overcome short-term showstoppers and to formulate long-term grand challenges related to energy technologies. These workshops have followed a common format that includes the development of a technology perspectives resource document prior to the workshop, a plenary session including invited presentations from technology and research experts, and topical panels to determine basic research needs and recommended research directions. Reports from the workshops are available on the BES website at http://www.sc.doe.gov/bes/reports/list.html.

The workshop began with a plenary session of invited presentations from national and international experts on science and technology related to nuclear energy. The presentations included nuclear technology, industry, and international perspectives, and an overview of the Global Nuclear Energy Partnership. Frontier research presentations were given on relevant topics in materials science, chemistry, and computer simulation. Following the plenary session, the workshop divided into six panels: Materials under Extreme Conditions, Chemistry under Extreme Conditions, Separations Science, Advanced Actinide Fuels, Advanced Waste Forms, and Predictive Modeling and Simulation. In addition, there was a crosscut panel that looked for areas of synergy across the six topical panels. The panels were composed of basic research leaders in the relevant fields from universities, national laboratories, and other institutions. In advance of the workshop, panelists were provided with a technology perspectives resource document that described the technology and applied R&D needs for advanced nuclear energy systems. In addition, technology experts were assigned to each of the panels to ensure that the basic research discussions were informed by a current understanding of technology issues.

The panels were charged with defining the state of the art in their topical research area, describing the related basic research challenges that must be overcome to provide breakthrough technology opportunities, and recommending basic research directions to address these challenges. These basic research challenges and recommended research directions were consolidated into Scientific Grand Challenges, Priority Research Directions, and Crosscutting Research Themes. These results are summarized below and described in detail in the full report.

Scientific Grand Challenges

Scientific Grand Challenges represent barriers to fundamental understanding that, if overcome, could transform the related scientific field. Historical examples of scientific grand challenges with far-reaching scientific and technological impacts include the structure of DNA, the understanding of quantum behavior, and the explanation of nuclear fission. Theoretical breakthroughs and new experimental capabilities are often key to addressing these challenges. In advanced nuclear energy systems, scientific grand challenges focus on the fundamental materials and chemical sciences that underpin the performance of materials and processes under extreme conditions of radiation, temperature, and corrosive environments. Addressing these challenges offers the potential of revolutionary new approaches to developing improved materials and processes for nuclear applications. The workshop identified the following three Scientific Grand Challenges.

Resolving the f-electron challenge to master the chemistry and physics of actinides and actinide-bearing materials.The introduction of new actinide-based fuels for advanced nuclear energy systems requires new chemical separations strategies and predictive understanding of fuel and waste-form fabrication and performance. However, current computational electronic-structure approaches are inadequate to describe the electronic behavior of actinide materials, and the multiplicity of chemical forms and oxidation states for these elements complicates their behavior in fuels, solutions, and waste forms. Advances in density functional theory as well as in the treatment of relativistic effects are needed in order to understand and predict the behavior of these strongly correlated electron systems.

Developing a first-principles, multiscale description of material properties in complex materials under extreme conditions.The long-term stability and mechanical integrity of structural materials, fuels, claddings, and waste forms are governed by the kinetics of microstructure and interface evolution under the combined influence of radiation, high temperature, and stress. Controlling the mechanical and chemical properties of materials under these extreme conditions will require the ability to relate phase stability and mechanical behavior to a first-principles understanding of defect production, diffusion, trapping, and interaction. New synthesis techniques based on the nanoscale design of materials offer opportunities for mitigating the effects of radiation damage through the development and control of nanostructured defect sinks. However, a unified, predictive multiscale theory that couples all relevant time and length scales in microstructure evolution and phase stability must be developed. In addition, fundamental advances are needed in nanoscale characterization, diffusion, thermodynamics, and in situ studies of fracture and deformation.

Understanding and designing new molecular systems to gain unprecedented control of chemical selectivity during processing.Advanced separations technologies for nuclear fuel reprocessing will require unprecedented control of chemical selectivity in complex environments. This control requires the ability to design, synthesize, characterize, and simulate molecular systems that selectively trap and release target molecules and ions with high efficiency under extreme conditions and to understand how mesoscale phenomena such as nanophase behavior and energetics in macromolecular systems impact partitioning. New capabilities in molecular spectroscopy, imaging, and computational modeling offer opportunities for breakthroughs in this area.