Polarized neutron reflectometer SHARAKU with 2-D MWPC in J-PARC

Yamazaki, Dai  ; Soyama, Kazuhiko  ; Miyata, Noboru*; Kasai, Satoshi*; Akutsu, Kazuhiro*; Hanashima, Takayasu*; Kubota, Masato ; Aoki, Hiroyuki  ; Suzuki, Junichi*; To, Kentaro  ; Nakamura, Tatsuya  ; Yamagishi, Hideshi*; Sakasai, Kaoru  

Polarized neutron reflectometry is one of the powerful methods to investigate various phenomena on the surfaces and interfaces of a variety of films with layered structures such as magnetic materials. In this instrument, a two-dimensional position-sensitive neutron detection system consists of multi-wire proportional chamber (MWPC) with helium-3 gas and its data reduction software have been developed for the measurement of off-specular reflectivity and grazing incidence small-angle neutron scattering (GISANS). Each wire signal is read out by amplifier-shaper-discriminator (ASD) individually to meet with demands for a fast counting response and high spatial resolution for the measurement at intense pulsed neutron sources. The pitch between anode/cathode wires is 1.0 mm. The spatial resolution was 1.8 mm. We report characterization results of 2-D MWPC system at BL17 and its applications to neutron reflectivity measurements.