Development of a bump cathode element for two-dimensional neutron detection

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

A neutron-detection element using circular cathode bumps was developed for two-dimensional neutron measurement, and an irradiation experiment was performed using a Cf neutron source. The element has triangularly arranged small-sized circular cathode bumps, and the bumps are linked together in the x- and y-directions for the detection of incident neutrons. The element was arranged in the pressure vessel with a fill gas of composition He/(15%)CF at 0.7 MPa. The detector system using bump cathode element exhibited a two-dimensional uniformity with a response of 10.1%. The average intrinsic spatial resolution was 1.89 mm full width at half maximum in the sensitive region, calculated by taking into account the track lengths of the secondary particles.