Two-dimensional gas-based neutron detector under high pressure gas condition

To, Kentaro  ; Nakamura, Tatsuya  ; Sakasai, Kaoru  ; Yamagishi, Hideshi*

A two-dimensional gas-based neutron detector system that can be operated under high-pressure was developed, and an irradiation experiment was performed using a Cf-252 neutron source. The pressure vessel of the developed detector system has 256 feedthroughs insulated by alumina ceramics for neutron-induced signals and 6 connectors for high voltage. The vessel could withstand pressures of up to 0.8 MPa and with a helium leakage of less than 10 Pam/s. The signals from neutrons clearly observed and can be discriminated from background signals such as -ray and electrical noises. The flat-field image showed good homogeneity and an average gain spread of approximately 7.7%. The system exhibits a -ray sensitivity of 1.110.