A fission neutron detector based on helium scintillator

Abstract

A new neutron detector is designed. Two 235UO2 target foils are used as radiators, and the 4He gas is used as scintillator in the detector. The detector combines the features of 235U and 4He fully, so it has some excellent performances, such as flat energy response to neutrons, better n/γ discrimination, etc. It can be used well to detect neutrons in a pulsed mixture radiation field. In this paper, the principle and structure of the detector are introduced. The energy depositions of different energies of neutrons and γ -rays in 4He gas are calculated. The neutron sensitivity, γ ray sensitivity, n/γ discrimination, and time response of the detector are investigated theoretically and experimentally. The neutron sensitivity is about 10-15 C·cm2, γ ray sensitivity is about 10-17 C·cm2, and time response is about 33.1 ns.