Development of two-dimensional micro-pixel gas chamber capable of individual line readout for neutron measurement

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

An improved micro-pixel detector element that showed high voltage tolerance was fabricated, and irradiation experiments using a Cf-252 neutron source were conducted on it. A gas-based neutron detection system capable of individual line readout, consisting of the developed detector element, gas chamber, amplifier-shaper-discriminator boards, and a fast data acquisition device, was constructed for the experiment. The micro-pixel gas chamber can identify signal-pulse peaks of neutrons and easily distinguish the neutron signals from background noises. The measured gas gain was approximately 280 at the supplied anode-cathode voltage of 670 V and total pressure of 0.5 MPa (0.45 MPa of He and 0.05 MPa of CF).