DD-fusion-neutron yield calibrations for NIF nTOF detector systems

We present an update and review of DD-fusion-neutron yield measurements inferred from multiple neutron time-of-flight (nTOF) detectors fielded at the National Ignition Facility (NIF). Many inertial confinement fusion experiments conducted at the NIF utilize 50/50 DT fuel, which produce primary DT-neutron yields that are often >50x higher than primary DD-neutron yields. Nuclear activation measurements of the primary DD-neutron yields in such experiments are often impractical and less accurate since the activated isotopes of interest may have large contributions from the higher energy DT neutrons. Thus, DD-neutron yields on most NIF experiments are inferred from nTOF detectors, which are calibrated using indium activation measurements on select DD-fuel experiments. We report the status and recent updates regarding calibration of the nTOF detectors' DD-neutron yield measurements.