Remarks on detecting high-energy deuterium–tritium fusion gamma rays using a gas Cherenkov detector

As fusion ignition conditions are approached using the national ignition facility (NIF), independent high-bandwidth gamma-ray fusion burn measurements become essential complements to information obtained from neutron diagnostics. The 16.75-MeV gamma rays that accompany deuterium–tritium (d+t) fusion can be detected using a high-bandwidth gaseous carbon dioxide Cherenkov threshold detector. The detection energy threshold was set by the CO2 gas pressure. A 1-GHz detector system was fielded successfully at the Omega laser facility, demonstrating unambiguous detection of high-energy fusion gamma rays from high-yield d+t implosions. An experiment to detect the ∼12.5 MeV d–t fusion gamma ray is described.