Development and installation of neutron detectors for engineering materials diffractometer at J-PARC

Sakasai, Kaoru  ; To, Kentaro  ; Nakamura, Tatsuya  ; Harjo, S.   ; Moriai, Atsushi; Ito, Takayoshi; Abe, Jun; Aizawa, Kazuya  ; Soyama, Kazuhiko  ; Katagiri, Masaki*; Rhodes, N. J.*; Schooneveld, E. M.*

Neutron detectors for Engineering Materials Diffractometer, named TAKUMI, at J-PARC have been developed under international cooperation between Rutherford Appleton Laboratory (RAL) and Japan Atomic Energy Agency (JAEA), and installed successfully at the end of March 2009. The detector size was 8051370217 mm which was about 1.5 times larger than those installed in ENGIN-X, ISIS facility, RAL. Neutrons are detected based on a nuclear reaction of Li(n, )H using ZnS/LiF scintillator. The data acquisition electronics and decoding module were also manufactured. The overall performances of the detectors have been tested using various sources. The results showed that the detectors had good performances such as a position resolution of 3 mm, a neutron detection efficiency of more than 50% at 1 -neutrons, and a -ray sensitivity of less than 10 at 1.3 MeV--ray by Co source, which met the requirements of TAKUMI, and they will be presented at the meeting.