Innovative Inorganic Fusion Magnet Insulation Systems

72206-Magnet systems for Next Step Option (NSO) fusion devices will require insulation systems that can tolerate exposure to high levels of radiation as well as both cryogenic and elevated temperatures. Currently available insulation systems either: (1) do not meet these requirements; or (2) compromise the magnet system design or economics to such an extent as to make them unfeasible. This project will develop new ceramic insulation systems, capable of being processed during the superconductor heat treatment, that meet the needs of NSO fusion devices. The new inorganic insulation systems will provide high radiation resistance and enhanced cryogenic and elevated temperature performance, with processing properties similar to traditional composite insulation systems. In Phase I, a prepreg form of a ceramic hybrid insulation, capable of being co-processed at Niobium-Tin reaction temperatures, was successfully developed. The ceramic insulation systems were tested mechanically and electrically, in combination with epoxy and cyanate ester organic matrix materials, and were also irradiated to assess their radiation resistance. Phase II will formulate new, low-cost ceramic insulation materials using low-cost fiber reinforcements that are compatible with high radiation and cryogenic environments. The best candidate materials will be characterized for their mechanical, electrical, and thermal properties at cryogenic and elevated temperatures. Then, they will be subjected to high doses of neutron and gamma radiation and tested mechanically following irradiation. Finally, subscale magnet prototype coil mockups will be fabricated and tested. Commercial Applications and Other Benefits as described by awardee: The development of a prepreg ceramic insulation should have commercial applications for fusion magnets, high field accelerator magnets, and medical instruments. All of these applications would become more viable with improved magnet processing, higher strength, and improved reliability. Such strong insulation would also find use in commercial heating elements, which would become cheaper and easier to fabricate.