Development and application of an in-situ SEOP He neutron spin filter
Oku, Takayuki ; Hayashida, Hirotoshi; Sakai, Kenji ; Shinohara, Takenao ; Nakamura, Mitsutaka ; Aizawa, Kazuya ; Arai, Masatoshi; Endo, Yasuo; Kakurai, Kazuhisa; Kira, Hiroshi*; Sakaguchi, Yoshifumi*; Suzuki, Junichi*; Ino, Takashi*; Hiraka, Haruhiro*; Shimizu, Hirohiko*; Okawara, Manabu*; Oyama, Kenji*
We have been developing an in-situ SEOP He neutron spin filter to apply it to pulsed neutron experiments at J-PARC/MLF. To introduce the He neutron spin filter into the instruments of the pulsed neutron facility such as J-PARC/MLF, it is important to make the system compact and stable, because the system is located inside thick and bulky radiation shields for high energy ray and neutrons. In this study, we have developed a compact laser optics with a volume holographic grating (VHG) element, and composed an in-situ SEOP He neutron spin filter. We have started to apply the He spin filer as an analyzer to polarized neutron small angle scattering and reflection measurements. A magnetic field imaging are also being tested with the two He neutron spin filter cells which are polarized by the ex-situ SEOP technique. In this paper, we report the design of our SEOP He neutron spin filter system and some results of the related polarized neutron beam experiments.