Neutron beam detection system and method for setting neutron beam detection system

摘要

Provided are a neutron ray detecting system and a method of setting a neutron ray detecting system that can set a determination threshold value to a suitable value. By acquiring the neutron ray wave height distribution of the neutron rays and the gamma ray wave height distribution of only the gamma rays included in the radiant rays, how much gamma rays are detected as noise can be ascertained in a case where a certain determination threshold value Q th is set. That is, a relationship between the determination threshold value Q th and detection accuracy can be ascertained. Additionally, since the neutron ray wave height distribution and the gamma ray wave height distribution are acquired on the basis of two measurements in a case where a filter (51) that cuts the neutron rays N is used and in a case where the filter (51) is not used, the relationship between the determination threshold value Q th and the detection accuracy can be accurately ascertained. Therefore, a determination threshold value adjusting unit (43) can adjust a suitable determination threshold value Q th in conformity with demanded detection accuracy on the basis of the neutron ray wave height distribution and the gamma ray wave height distribution.