A Neutron depolarization measurement of a single crystal Fe by using a He neutron spin filter and magnetic super-mirrors

Oku, Takayuki   ; Kira, Hiroshi*; Hayashida, Hirotoshi*; Sakai, Kenji ; Hiroi, Kosuke  ; Okudaira, Takuya; Ino, Takashi*; Shinohara, Takenao   ; Suzuki, Junichi*; Kakurai, Kazuhisa*; Aizawa, Kazuya  

We performed demonstrative experiments using the He-NSF at small-angle scattering (BL15 TAIKAN), reflection (BL17 SHARAKU) and imaging instrument (BL22 RADEN) of J-PARC MLF, and got reasonable results. Then, we have performed a demonstrative study of polarized-neutron single-crystal diffraction measurement at BL18 (SENJU). The sample was a single crystal Fe. As the result, expected flipping ratios of Bragg beaks were not observed. Therefore, we have performed a depolarization experiment of neutrons transmitted through the sample, and found out neutron severe depolarization occurred in the sample which was almost magnetically saturated under an applied magnetic field of 4.2 kG. In this paper, we will show the experimental results of the depolarization experiment of neutrons transmitted through the single crystal Fe and discuss them.