Development of a circular-shape cathode element with pixel size of 0.8 0.8 mm for two-dimensional neutron detector

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

A new detector element with a smaller pixel size is developed for a multiwire-type neutron detector with an individual readout method. The pixel size of the developed element is 0.8 0.8 mm, and the element consist of multiwire anodes for the gaseous amplification and circular-shaped cathode bumps for collecting the charges generated by neutrons and detecting the position of incident neutrons. The sensitive area was 102.4 102.4 mm with a pitch of 0.8 mm in X and Y directions. Uniform neutron irradiation tests for the developed detector element were conducted by using a Cf-252 neutron source. As a result, excellent uniformity was exhibited as a two-dimensional neutron detector system, and the spread of neutron counts in all pixels was 9.9%. The position resolution was 1.89 mm at half-maximum. The measured gamma sensitivity using a Co-60 source was 3.87 10 and the background count rate was 8.22 10 cps/pixel.