The Fusion Energy Sciences program supports the operation of the following national scientific user facilities:
DIII-D Tokamak Facility:
DIII-D, located at General Atomics in San Diego, California, is the largest magnetic fusion facility in the U.S. and is operated as a DOE national user facility. DIII-D has been a major contributor to the world fusion program over the past decade in areas of plasma turbulence, energy and particle transport, electron-cyclotron plasma heating and current drive, plasma stability, and boundary layers physics using a “magnetic divertor” to control the magnetic field configuration at the edge of the plasma. DOE’s Office of Science, Fusion Energy Sciences program is a major supporter in the operation of this facility.
Alcator C-Mod at the Massachusetts Institute of Technology is operated as a DOE national user facility. Alcator C-Mod is a unique, compact tokamak facility that uses intense magnetic fields to confine high-temperature, high-density plasmas in a small volume. One of its unique features are the metal (molybdenum) walls to accommodate high power densities. Alcator C-Mod has made significant contributions to the world fusion program in the areas of plasma heating, stability, and confinement of high field tokamaks, which are important integrating issues related to ignition of burning of fusion plasma. DOE’s Office of Science, Fusion Energy Sciences program, is a significant contributor to the operation of this facility.
National Spherical Torus Experiment (NSTX):
NSTX is an innovative magnetic fusion device that was constructed by the Princeton Plasma Physics Laboratory in collaboration with the Oak Ridge National Laboratory, Columbia University, and the University of Washington at Seattle. It is one of the world’s two largest embodiments of the spherical torus confinement concept. Like DIII-D and Alcator C-Mod, NSTX is also operated as a DOE national scientific user facility. NSTX has a unique, nearly spherical plasma shape that provides a test of the theory of toroidal magnetic confinement as the spherical limit is approached. Plasmas in spherical torii have been predicted to be stable even when high ratios of plasma-to-magnetic pressure and self-driven current fraction exist simultaneously in the presence of a nearby conducting wall bounding the plasma. If these predictions are verified, it would indicate that spherical torii use applied magnetic fields more efficiently than most other magnetic confinement systems and could, therefore, be expected to lead to more cost-effective fusion power systems in the long term. DOE’s Office of Science, Fusion Energy Sciences program is the major contributor to the operation of this facility.
Other Fusion Energy Sciences facilities that support collaborative research include:
ITER (Latin for “the way”), is a critical step between today’s studies of plasma physics and tomorrow’s fusion power plants producing electricity and hydrogen. Project partners are China, the European Union, India, Japan, Russia, South Korea, and the United States. ITER is technically ready to start construction, with experimental operations planned to begin in approximately 10 years. The site selected for the project is Cadarache, in southeastern France. ITER is expected to operate for 20 years, and to demonstrate production of at least 10 times the power used to heat the fusion fuel. The U.S. ITER Project Office, a partnership of Oak Ridge National Laboratory (ORNL) and Princeton Plasma Physics Laboratory, is responsible for project management of U.S. activities to support construction of the international research facility. It is located at Oak Ridge so that the U.S. ITER program can take advantage of the project management experience developed by ORNL during the construction there of the Spallation Neutron Source (SNS).
Madison Symmetric Torus (MST):
The MST is a toroidal, reversed field pinch (RFP) machine that produces hot plasma for applications in both fusion energy research and astrophysical plasmas. This facility is located at the University of Wisconsin Madison, and enables research with three coupled goals: to advance the magnetic configuration known as the reversed field pinch as a potential fusion energy source, to investigate specific fusion energy science issues that are of general application to fusion energy research, and to explore plasma phenomena that have physics connections to plasma processes in the cosmos.