Development of a compact vertical splitting system for the cold neutron beam at JRR-3

Tamura, Itaru  ; Maruyama, Ryuji   ; Yamazaki, Dai  ; Nakamura, Kiyoshi; Yamamoto, Kazuyoshi ; Aizawa, Kazuya  ; Soyama, Kazuhiko  

To achieve efficient implementation of usage of neutron beam instruments, the instruments were rearranged at C2 cold neutron beam line at JRR-3 by using a newly developed compact vertical splitting system. The splitting system has two compact multi channel benders. The bender has been developed using Ni/Ti supermirrors coated on both sides of 0.2 mm thickness silicon substrates. The curvature radius of the bender is 938 mm and the length of the bender is 320 mm yielding deflection angles of 20. Supermirrors with m=3 were deposited on both sides of silicon substrate by an ion beam sputtering apparatus in JAEA. Neutron flux at the end of the neutron guide that installed at the bender exit of which the deflection angle is 20 was measured by the gold foil activation method. It was measured 1.58 10 n/cm/s. The present study showed that the supermirrors coated on both sides with high reflectivity are suitable for the compact bender.