Lead P.I. - Dr. David Sprouster

Realization of fusion energy requires high-performance radiation-tolerant structural and functional materials that can withstand the extreme temperature and radiation environments for the fusion first-wall, blanket structures and plasma-facing components. A significant gap in our current understanding is the behavior of materials under the high neutron doses and transmutant H and He levels intrinsic to fusion reactors. Although some experimental data have been obtained in fission reactors for damage levels approaching realistic relevant doses, the level of simultaneous transmutant He generation from fission reactors is more than two orders of magnitude below that from fusion reactors. Therefore, severe performance degradation due to the synergies between neutron damage and transmutation products is expected for numerous candidate materials for a variety of applications in fusion reactor concepts like the Demonstration Power Plant (DEMO) in EU/Japan or the Fusion Neutron Science Facility (FNSF) in the US. Specific material examples where critical data is missing include reduced activation ferritic-martensitic (RAFM) steels for the first-wall/blanket, tungsten alloys for divertor, copper alloys for high-heat flux components, SiC/SiC ceramic composites for coolant channels, lithium based oxides for solid breeders (to name a few). Until a fusion prototypic neutron source (FPNS) becomes available, grassroots research that can emulate the effect of transmutation products for future validation with 14 MeV neutrons is required using fission neutrons and accelerator based energetic ions. This project leverages advanced synchrotron-based characterization methods of spectroscopy and scattering to characterize the material-dependent transmutation pathways in fusion relevant material systems including tungsten and tungsten alloys, RAFM steels and ultra-high temperature ceramics.