부산대학교 도서관

The Gamma-to-Electron Magnetic Spectrometer (GEMS) diagnostic is designed to measure the prompt γ -ray energy spectrum during high yield deuterium-tritium (DT) implosions at the National Ignition Facility (NIF). The prompt γ -ray spectrum will provide "burn-averaged" observables, including total DT fusion yield, total areal density (ρR), ablator ρR, and fuel ρR. These burn-averaged observables are unique because they are essentially averaged over 4π, providing a global reference for the line-of-sight-specific measurements typical of x-ray and neutron diagnostics. The GEMS conceptual design meets the physics-based requirements: ÄE/E = 3%-5% can be achieved in the range of 2-25 MeV γ -ray energy. Minimum DT neutron yields required for 15% measurement uncertainty at low-resolution mode are: 5 x 1014 DT-n for ablator ρR (at 0.2 g/cm²); 2 x 1015 DT-n for total DT yield (at 4.2 x 10-5 γ /n); and 1 x 1016 DT-n for fuel ρR (at 1 g/cm²). [ABSTRACT FROM AUTHOR]