Science Highlights | U.S. DOE Office of Science (SC)

Illustration of alpha fusion processes in stars and reactions used on Earth floating above an image of the Earth

Predictive Theory Revises Understanding of Alpha Processes During the Big Bang and in Massive Stars

Theoretical calculations enable more accurate determination of reaction rates for modelling primordial lithium-6 abundance and massive stars’ lifecycle.

Chromium-62 is near the center of a region of the nuclear chart referred to as an island of inversion. The experiment in this research measured observables for the rare isotope chromium-62 that help explain the properties of even rarer species.

Experiment Reveals Competing Nuclear Shapes in the Rare Isotope Chromium-62

Successfully modeling chromium-62 hints at an interesting structure for neutron-laden calcium-60.

Artist’s depiction of the aluminum-22 nucleus if it exists in a halo state. This nucleus contains 13 protons (red) and 9 neutrons (blue). Halo nuclei are characterized by having one or more nucleons existing at an extended distance from a compact core.

Researchers Obtain the First High-Precision Mass Measurement of Aluminum-22

The Facility for Rare Isotope Beams enables a high-precision mass measurement at the edge of the nuclear chart.

Wavefunction matching replaces the short distance part of the two-body wavefunction for a realistic interaction with that of a simple easily computable interaction. The result is a new interaction that can be handled in quantum many-body calculations.

Making Difficult Quantum Many-Body Calculations Possible

Solving quantum many-body problems with wavefunction matching.

A simulation of a rapidly accreting white dwarf showing a proposed site for the intermediate (i) process and the Summing NaI (SuN) detector. The research studied the 139Ba+n reaction, constrained by the beta decay of 140Cs into 140Ba.

Nuclear Physics Experiment Helps Identify Conditions for a New Astrophysical Process

New nuclear physics measurements shed light on the synthesis of heavy elements in stars.

Team members pose in the clean room (left). Thermal image of the 10.4 kW uranium-238 beam on the target (top right). Three never-before-seen isotopes, shown to the right of the red line on the particle identification plot (bottom right).

Scientists Accelerate Uranium Beam with Record Power

The Facility for Rare Isotope Beams opens a new research avenue and observes three new rare isotopes.

Charge radii differences in mirror nuclei, which have opposite numbers of protons and neutrons, can help constrain parameters for the equation of state nuclear matter, which describes the properties of astrophysical objects such as neutron stars.

“Mirror” Nuclei Help Connect Nuclear Theory and Neutron Stars

Charge radii measurements of silicon isotopes test nuclear theories and guide descriptions of nuclear matter.

A photon is absorbed by the ground state of helium-4. This excites the transition to the first excited state of helium-4, which sits just above the energy threshold for separation into a proton and a hydrogen-3 nucleus.

Exciting the Alpha Particle

New calculations confirm recent experimental results on the transition between the alpha particle and its first excited state.

The chart of nuclides sorts isotopes by their proton vs. neutron numbers. This region shows newly discovered isotopes (yellow) that were produced at the Facility for Rare Isotope Beams by fragmenting a stable platinum-198 beam (orange outline).

The Facility for Rare Isotope Beams Observes Five Never-Before-Seen Isotopes

The discovery of new isotopes demonstrates the user facility’s discovery potential.

Theoretical calculations predict a complex excited state (0+) for helium-4 (4He) at the 20.21 MeV energy level. This state involves a coupling of three cluster configurations: helium-3 and a proton, helium-3 and a neutron, and two helium-2 nuclei.

New Calculations Solve an Alpha Particle Physics Puzzle

A new experimental measure of Helium-4’s transition from its ground energy state to an excited state closes an apparent gap with theoretical predictions.

The floating block method pictured as ice blocks and the sea. The method applies a filtering process called imaginary time evolution to two Hamiltonians, represented by ice and sea. It gives the overlap between the two Hamiltonians’ lowest energy states.

Computing How Quantum States Overlap

The floating block method provides the tools to compute how quantum states overlap and how to build fast and accurate emulators of those systems.