The Material Plasma Exposure eXperiment (MPEX) is a next-generation linear plasma device that will support study of the way plasma will interact long term with the components of future fusion reactors—in particular, the divertor, the power and particle “exhaust system” of a fusion reactor.

MPEX represents a shift from the historical direction of the plasma-material interaction field, which for many years focused on the effect that materials had on plasma, but not on the effect that plasma had on materials

As of September 2020, MPEX completed a Department of Energy (DOE) Critical Decision-3A Independent Project Review, —which includes approval for the preparation of the facility and long-lead procurements—moving it one step closer to the start of construction. The device assembly is projected to begin in the spring of 2023.

MPEX will support materials research relevant for next-generation fusion devices, such as a fusion pilot plant.

MPEX is a DOE Office of Science project managed by Oak Ridge National Laboratory.