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DOE Under Secretary for Science Dabbar celebrates progress on MPEX fusion materials device

Department of Energy Under Secretary for Science Paul Dabbar (center) joined ORNL and DOE leaders for a ribbon-cutting ceremony to mark progress toward a next-generation fusion materials project.

Department of Energy Under Secretary for Science Paul Dabbar joined Oak Ridge National Laboratory leaders today for a ribbon-cutting ceremony to mark progress toward a next-generation fusion materials project. The Material Plasma Exposure eXperiment, or MPEX, aims to build a first-of-a-kind linear plasma device to support study of the long-term effects of plasma interactions on the materials necessary for future fusion reactors.                        

“This project is an important element in the U.S. fusion portfolio and will offer a world-leading materials resource for fusion energy development,” Dabbar said.

Fusion has the potential to provide abundant, clean energy, but a major challenge is development of materials that can withstand conditions in a practical fusion power reactor. Inside a fusion reactor, materials can experience temperatures hotter than the sun, magnetic fields hundreds of thousands of times greater than earth’s, and a barrage of neutrons and ions that can change the atomic structure and erode materials. Current materials are sufficient for the experimental devices planned or underway, such as the international ITER collaboration, but not for a long-running power-producing reactor.

ORNL has a substantial cadre of scientists and engineers working on this materials challenge. MPEX will offer a new platform to accelerate that effort and will serve as a resource for fusion development activities across DOE and other sectors.

“ORNL brings together an exceptional combination of talent and capabilities to address key challenges along the path to realizing the promise of fusion energy,” said ORNL Director Thomas Zacharia.  

 The lab is also home to US ITER, which delivers the United States’ hardware contributions to the international ITER fusion project now under construction in France. In addition, ORNL researchers contribute engineering and scientific expertise to fusion devices across the United States and the globe.

“The combination of experimental, modeling and simulation, and component fabrication expertise at ORNL forms a unique test bed to enable and accelerate development of fusion energy,” said Kathy McCarthy, ORNL associate lab director for Fusion and Fission Energy and Science.

The MPEX project recently completed an independent project review in advance of DOE authorization to begin procurement and fabrication of major long-lead items for the device. That hardware will include a superconducting magnet system, two gyrotron microwave sources, a high voltage power supply, plus reconfiguration of an existing ORNL building to be the future home of MPEX.

Pending DOE authorization expected later this year, MPEX will begin procurement activities in preparation for the start of fabrication in 2021. MPEX is supported by DOE’s Office of Science.

ORNL is managed by UT-Battelle for the U.S. Department of Energy's Office of Science, the single largest supporter of basic research in the physical sciences in the United States. DOE’s Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit