A Large-area two-dimensional scintillator detector with a wavelength-shifting fibre readout for a time-of-flight single-crystal neutron diffractometer

Nakamura, Tatsuya  ; Kawasaki, Takuro   ; Hosoya, Takaaki*; To, Kentaro  ; Oikawa, Kenichi   ; Sakasai, Kaoru  ; Ebine, Masumi ; Birumachi, Atsushi; Soyama, Kazuhiko  ; Katagiri, Masaki*

A two-dimensional scintillator-based neutron detector that has a neutron-sensitive area of 256 256 mm with a pixel size of 4 mm was developed. The detector was designed to be compact and modular with the smallest dead area for the SENJU time-of-flight Laue single-crystal diffractometer to be constructed in the Materials and Life Experimental Science Facility at the Japanese Proton Accelerator Research Complex. Two ZnS/ scintillator screens with an optimized scintillator thickness sandwiched the cross-arranged Wavelength-shifting fibre arrays to ensure a high detection efficiency for thermal neutrons. The prototype detector exhibited a detector efficiency of 40 1 % for 1.6- neutrons and a Co -ray sensitivity of 6.00.1 , which fulfilled the required detector specifications for SENJU.