Development of high-position resolution 1D-scintillation detector

Sakasai, Kaoru  ; Nakamura, Tatsuya  ; To, Kentaro  ; Soyama, Kazuhiko  ; Rhodes, N.*; Schooneveld, E.*

A prototype 1D-scintillaton detector has been developed. The detector has a small sensitive area of 42 mm 196 mm and a position resolution of 1.5 mm that is higher than that of TAKUMI detectors at MLF/J-PARC. The incident neutrons are detected based on ZnS/LiF scintillation techniques. The scintillation light produced in ZnS/LiF as a result of nuclear reaction of neutrons with 6Li nuclei is detected by photomultiplier tubes (PMTs) via optical fibers set in the back of the scintillator. To determine the incident neutron position and to reduce the number of PMTs, the 2Cn coding was adopted in the fiber arrangement. The electric signals from the PMTs are sent to the data acquisition electronics and the decoder. The fabricated detector showed excellent performances such as a neutron detection efficiency of 67 at a neutron wavelength of 1.8 and a sensitivity of less than 10 at a energy of 1.3 MeV.