Development for upgrading Japanese ENGIN-X type linear scintillation neutron detectors; Development of new ZnS scintillator, light reflector and digital signal processing module

Nakamura, Tatsuya  ; Katagiri, Masaki; Birumachi, Atsushi; Ebine, Masumi ; Tsutsui, Noriaki*; Soyama, Kazuhiko  ; Schooneveld, E. M.*; Rhodes, N. J.*

New ZnS scintillator, light reflector and digital signal processing modules were developed to upgrade the Japanese ENGIN-X type linear scintillation neutron detector. The developed ZnS/BO scintillator improved detector efficiency by a factor 1.2 for neutrons with a wavelength of 1 whilst the detector maintained similar sensitivity and multi-count ratio compared to the present AST (4:1) scintillator. The paint coating less light reflector was developed with an aluminum reflector with etched surface. The detector implemented with this reflector exhibited similar detector performances with paint coating reflectors, confirming feasibility of the reflector with long-term stability. The digital signal-processing module incorporating photon-counting method was successfully developed. The fully digitalized photon counting system improved a temperature stability of neutron counts significantly comparing to the present analogue system.