Facilities

Setting a foundation for a future fusion power plant requires world-class facilities for research and development.

The DIII-D National Fusion Facility and the National Spherical Torus Experiment-Upgrade (NSTX-U) are world-leading Office of Science User Facilities. Scientists from National Laboratories, universities, and private industry use these facilities to improve magnetic confinement approaches and test prototype technology.

Researchers use these facilities to address major gaps, including:

  • New heating and current drive technology
  • Disruption avoidance and mitigation
  • Enhanced plasma confinement
  • Plasma control
  • Core-edge integration
  • Development of steady state burning plasma scenarios, and
  • Integrating plasma facing components, including liquid metals.

Using these facilities, private sector fusion companies can resolve science and technology challenges associated with their concepts. The User Facilities also play a key role in upcoming technologies such as artificial intelligence for fusion and training the next generation of scientists.

Other scientific facilities for fusion under construction include ITER and the Material Plasma Exposure eXperiment.

DIII-D

The DIII-D National Fusion Facility at General Atomics (an Office of Science User Facility) is the most adaptable and well-diagnosed magnetic confinement facility in the U.S. It can magnetically confine plasmas at temperatures relevant to burning plasma conditions. (Burning plasma is self-heating and can sustain itself; it is a necessity for producing power from fusion.) Researchers perform experiments on DIII-D where they study the stability and confinement of fusion-grade plasmas under a variety of conditions.

DIII-D’s strengths include a set of advanced diagnostic systems, heating and current drive actuators, and a multi-institutional research team. These characteristics make it well suited for closing science and technology gaps as well as building a foundational understanding of burning plasma.

Researchers at DIII-D focus on:

  • Using new configurations of diverters,
  • Assessing a range of materials for the interior walls,
  • Developing new high-powered heating systems for fusion pilot plants,
  • Validating predictive models of energetic particles, and
  • Pushing the limits of and expanding our understanding of the physics of tokamak plasmas.

National Spherical Torus Experiment-Upgrade (NSTX-U)

The National Spherical Torus Experiment-Upgrade (NSTX-U) is an Office of Science User Facility at DOE’s Princeton Plasma Physics Laboratory. It is used to close remaining critical gaps in the science and technology of spherical tokamaks.

Spherical tokamaks are fusion devices with magnetic fields shaped like cored apples. NSTX-U is the world’s most powerful one. It has external heating of approximately 19 megawatts, toroidal magnetic fields as high as one Tesla, and plasma currents as high as two megaamperes. With its strong magnetic curvature, powerful heating systems, and advanced diagnostics, NSTX-U allows scientists to study plasma at a higher ratio of plasma pressure to confining magnetic fields than at any other tokamak. It is ideal for studying the interactions between plasma waves and fast fuel ions that are relevant to burning plasma science.

The NSTX-U program aims to show that spherical tokamaks may enable higher power density that could lead to reduced device size. They could potentially enable less recirculating power, which would make them less expensive. Put together, this technology could lead to an option for an affordable and compact fusion power plant.

NSTX-U’s unique exhaust environment also allows researchers to test plasma-facing component systems. Its planned liquid metal divertor research program will help scientists assess a potentially more effective way to handle fusion heat and particle exhaust.

NSTX-U provides resources beyond fusion energy research. Its capabilities will also enable a first-of-a-kind detailed laboratory study of plasma processes relevant to astrophysical systems.

ITER

ITER is currently one of the largest science experiments in the world. It is a major fusion research facility under construction in St. Paul-lez-Durance, France by an international partnership of seven Members. The partners are the U.S., China, the European Union, India, Korea, Japan, and the Russian Federation. ITER is co-owned and co-governed by the seven Members.

Researchers expect two planned experimental outcomes from ITER.

The first is to reach the “burning plasma” regime. This regime occurs when heat generated by the fusion process is higher than the heat supplied from external sources. At this point, the plasma is self-heating. Reaching this state is currently beyond the state-of-the-art. ITER creating this self-sustaining burning plasma will provide scientific knowledge necessary to reach practical fusion power.

The second outcome is to sustain that burning plasma for several hundred to a few thousand seconds, considered a “long” duration. At this point, the plasma and adjacent structures would achieve equilibrium conditions.

In reaching this state, ITER is expected to provide fusion power output of up to 500 megawatts, comparable to many commercial power generation plants. It will provide an experimental industrial-scale platform that will support the development of pilot plants in the private sector. It will also enable U.S. supply chains, which will help keep the U.S. competitive internationally.

As a co-owner and Member of ITER, the U.S. contributes in-kind hardware components and financial contributions for the ITER Organization management and overhead. U.S. companies, DOE National Labs, and U.S. universities contribute to the design, fabrication, and delivery of ITER’s hardware. There are also a number of U.S. scientists who work on site.

U.S. investment in ITER has advanced the nation’s industrial capabilities for a fusion power industry. It resulted in more than $1.4 billion awarded to American companies through 2024 in 46 states.

Material Plasma Exposure eXperiment (MPEX)

FES is developing a first-of-a-kind, world-leading experimental facility called the Material Plasma Exposure eXperiment (MPEX) at DOE’s Oak Ridge National Laboratory.

MPEX will allow scientists to explore solutions to problems caused by the interactions between plasma and materials. It will enable dedicated studies of these interactions at a scale not previously accessible.

The overall goal of this project is to create a new class of fusion materials science. This science will help researchers anywhere in the world who are studying the combined effects of fusion-relevant heat, particles, and neutron fluxes.

 

Learn more about research supported by the Fusion Energy Sciences program: