Using real-time nuclear activation detectors for measuring neutron yields from D(D, T)n reactions on the national ignition facility (NIF)

The National Ignition Facility (NIF) has 48 Real-Time Nuclear Activation Detectors distributed around the target chamber capable of measuring deuterium-triton reaction neutron yields with high precision. Here, in this work, we extend this functionality to deuterium–deuterium (DD) reaction neutrons using a nuclear reaction that occurs in the detector’s scintillator material. The corresponding decay of the activated material has a very short half-life of 5 s, which necessitates rapid data collection immediately following an experiment. In this regime, dead time can be very high (>50%) adding significant uncertainty to the measurement. To combat this, we have developed a dead time model that can self-consistently describe the measured data. Initial results show reasonable agreement (within 20%) with DD neutron yields from neutron time-of-flight spectrometers.. Authors: Lahmann, B. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000245998463); Hahn, K. D. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000188067426); Henry, E. A. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000315806982); Munteanu, F. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0009000717473356); Schlossberg, D. J. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000287139448). DOE Contract: AC52-07NA27344. Subjects: 73 NUCLEAR PHYSICS AND RADIATION PHYSICS