Cryogenic neutron detector comprising an InSb semiconductor detector and a supercritical helium-3 gas converter

Nakamura, Tatsuya  ; Katagiri, Masaki; Aratono, Yasuyuki; Kanno, Ikuo*; Hishiki, Shigeomi*; Sugiura, Osamu*; Murase, Yasuhiro*

We evaluated the neutron-detection characteristics of a proposed cryogenic neutron detector comprising an InSb semiconductor detector and a helium-3 gas converter. The neutron detector was operated at 4.2 K with helium-3 gas filling up to 1.5 atm, at which the density of the helium-3 nucleus corresponds to that at 160 atm at room temperature. The secondary particles generated by the He(n,p) T reaction were successfully detected by the InSb detector with a time response of 80 nsec at all tested gas pressures.