Improved Signal Processing Algorithm for the 3He Proportional Chamber in High Gamma-Ray Fields

In neutron measurement system, neutrons can be detected by collecting the neutron-induced secondary charged particles. In this detector, they can be easily discriminated by pulse height analysis method (PHA method), because pulse height of gamma-ray signals is much lower than that of neutron signals. Neutron-gamma separation using the 3He proportional chamber were carried out at high gammaray fields of 500 mR/h and 1 R/h. From the energy spectra, it was confirmed that discrimination boundary to discriminate the neutron and gamma-ray signals using the existing PHA method was ambiguous in high gamma-ray fields. Whereas, rise-time-to-pulse-height ratio spectra, which was obtained using the proposed algorithm in this study, showed good performance even at the high gamma-ray exposure rate. Applying the algorithm to the neutron measurement system, more precise measurement is expected to be possible even in high gamma-ray fields.