Simultaneous measurements of DT fusion gamma-ray and neutron-induced secondary gamma-ray using Gas Cherenkov Detector

Abstract

A Gas Cherenkov Detector (GCD) which captures 16.75 MeV DT fusion γ-rays has been developed by Los Alamos National Laboratory in collaboration with Lawrence Livermore National Laboratory and Atomic Weapons Establishment. Due to the fast time response (∼ 120 ps), the GCD will be an essential instrument for National Ignition Facility (NIF) fusion reaction history studies. A challenge faced by the GCD is potential interference of primary DT fusion γ-rays (γ p ) with various secondary γ-rays (γ s ). NIF implosions produce 14 MeV DT neutrons (n o ) that induce the production of γ s from reactions on capsule materials (12C, 16O) and hohlraum materials (Au, U, Al). Experimental characterization of the GCD responses to various gamma rays is required for accurate measurements of NIF fusion reaction history. Our primary experimental goal in this work is to simulate the neutron-induced secondary gamma production of a NIF hohlraum.