A Micro pixel chamber based neutron imaging detector ( NID) with boron converter for energy-resolved neutron imaging at J-PARC

J-PARCにおけるエネルギー分析型中性子イメージングのためのホウ素コンバータを用いたマイクロピクセルチェンバー型中性子イメージング検出器

Parker, J. D.*; 篠原 武尚   ; 原田 正英   ; 林田 洋寿*; 廣井 孝介  ; 甲斐 哲也   ; 松本 吉弘*; 及川 健一   ; 瀬川 麻里子   ; Su, Y. H.  ; 高田 淳史*; 谷口 幹幸*; 谷森 達*; 鬼柳 善明*

Parker, J. D.*; Shinohara, Takenao; Harada, Masahide; Hayashida, Hirotoshi*; Hiroi, Kosuke; Kai, Tetsuya; Matsumoto, Yoshihiro*; Oikawa, Kenichi; Segawa, Mariko; Su, Y. H.; Takada, Atsushi*; Taniguchi, Tomoyuki*; Tanimori, Toru*; Kiyanagi, Yoshiaki*

At the Energy-Resolved Neutron Imaging System RADEN of the J-PARC MLF, we take advantage of the accurate measurement of neutron energy by time-of-flight to perform energy-resolved neutron imaging. To carry out measurements at RADEN, we have been developing and testing cutting-edge detector systems employing micro-pattern detectors and high-speed, all-digital data acquisition systems. One such detector, the Micro Pixel Chamber based Neutron Imaging Detector (NID), provides a spatial resolution of less than 250 m FWHM, 26% detection efficiency for thermal neutrons with He for conversion, and count rate capacity of 8 Mcps. By replacing the He gas with a boron-based converter, we aim to increase the count rate capacity three-fold while maintaining good spatial resolution. This is made possible by the significantly reduced event size for the alpha from the B-neutron interaction as compared to the lighter proton and triton in the He case.