Nova upgrade design support threats from radiation effects in the proposed nova upgrade

The program described in this report deals with the proposed Nova Upgrade facility, in which Lawrence fiV~ National Laboratory (LLNL) expects to generate typically 20 MJ of total fbsion energy. The Nova Upgrade is considered the next practical step ailer Nova before work begins on development of the Laboratory Microfusion Facility by which LLNL expects to generate 100-1000 MJ of total fusion energy. SRI International’s contributions have been to work with LLNL to understand the radiation-induced vaporizmion, melting, fracture, and fragmentation resulting from the effects of X-rays, neutrons, and debris irradiation on the target chamber wall, the steel feeder tubes of the cryogenic target holder assembly, and the optics debris shields. We have assessed the major collateral effects of direct and indirect damage from radiation and shrapnel debris on the optics debris shields and have suggested alternative materials and designs to alleviate the effects of radiation and debris. We also analyzed a technique LLNL has developed for producing hot X-rays in a shielded environment that uses a lithium hydride shell to scatter hot X-rays from the source to an experimental target area while using a cone to prevent direct cold-sou.me radiation and neutrons &cm reaching the experimental target. There do not appear to be any “show stoppers” to prevent recommending continued development of the Nova Upgrade for inertial confinement fusion (ICY) experiments and nuclear effects testing.