The Distribution of Neutron Absorbing Time in the Neutron Detector of the GAMMA-400 Space Observatory

Abstract The neutron detectors (ND) have been designed for the future GAMMA-400 space observatory with 3 He-counters and 6 LiF/ZnS(Ag) scintillation screens. The ND contribution in the rejection factor for protons in the GAMMA-400 is considered with significantly different number of neutrons generated in the electromagnetic and hadronic cascades. The ND is predominantly made from polyethylene, it has sizes of 100×100×10 cm 3 . GEANT4 simulation was obtained by the differential distribution of neutron absorbing time as the function of the registration time for different 3 He, 6 Li concentration. Nomograms were constructed for determining neutrons miscount depending on the number of neutrons crossing the ND and time resolution of the ND. The simulation results showed that the ND with 33 3 He-counters detected the neutron fluence 0.23 n/cm 2 without neutrons miscount.