A fission neutron detector based on helium scintillator

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.