The fusion diagnostic gamma experiment: A high-bandwidth fusion diagnosticof the National Ignition Facility

Diagnostics for the National Ignition Facility/inertial confinement fusion program must include good characterization of the fusion source. Ideally, d iagnostics would measure the spatially resolved history of the fusion react ion rate and temperature. Existing diagnostics can satisfy this goal only p artially. One class of new techniques that could play a major role in high- yield diagnostics is measurements based on fusion gamma rays. The fusion di agnostic gamma experiment can perform energy-resolved measurements of (D,T) fusion reaction rates. This diagnostic is based on the 16.7 MeV grays that are produced by (D, T) fusion. The gamma rays are free of spectral dispers ion and can be detected (via Compton recoil electrons) with a high bandwidt h Cherenkov detector. A simple magnetic monochromator selects signals from the 16.7 MeV grays and reduces background signals from nonfusion gamma rays . (C) 1998 American Institute of Physics. [S0034-6748(99)59701-3].