Multiplexed gas Cherenkov detector for reaction-history measurements

A diagnostic is being designed for the National Ignition Facility, using fusion gamma rays to measure highly time-resolved bang times and deuterium-tritium (d-t) interaction rates for imploding inertial fusion capsules. As a complement to neutron-based methods, gas Cherenkov detectors were chosen for this purpose because of proven ultrahigh bandwidth, thresholding versatility, and minimal time-of-flight dispersion. Gas Cherenkov detector prototypes, involving streak cameras and fast photomultiplier, microchannel plate detectors, are being tested using d-t implosions at the Omega Laser Facility. The possibility of simultaneous streak camera and photomultiplier, microchannel plate recordings of a source in one gas Cherenkov detector instrument is advantageous for reasons of independent measurement and extended reaction-history coverage. A multiplexed gas Cherenkov detector system was demonstrated successfully using electron pulses produced by the Idaho State University linear electron accelerator. A reaction-history diagnostic scheme composed of several types of detectors is proposed. The detectors considered reflect current and improving technology that allows coverage over a significant range of a reaction history generated from National Ignition Facility implosions