Neutron-Induced Signal Measurements in Cables on OMEGA

The National Ignition Facility (NIF) and the Laser Megajoule Facility (LMJ) are currently under construction in the U.S. and France, respectively. Ignited targets at these facilities are anticipated to produce up to 10$^{19}$ DT neutrons. For approximately 500 ns after ignition, the NIF and LMJ target diagnostics and control systems will work under extremely harsh radiation conditions. In particular, neutron-induced signals in cables can compromise or destroy diagnostic instruments and control systems. Recent results of neutron-induced signal measurements at 30 kJ in different cables at the 60-beam OMEGA Laser Facility will be reported. Based on these results, specific recommendations on cable selection for the NIF and LMJ will be given. Neutron-background mitigation techniques in the NIF neutron time-of-flight diagnostics will be presented. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under the Cooperative Agreement No. DE-FC52-92SF19460.