高分解能中性子共鳴スピンエコー法のためのビーム発散補正ミラーの開発

A Beam divergence correction mirror for neutron resonance spin echo

丸山 龍治   ; 日野 正裕*; 林田 洋寿; 北口 雅暁*; 山崎 大  ; 海老沢 徹*; 曽山 和彦  

Maruyama, Ryuji; Hino, Masahiro*; Hayashida, Hirotoshi; Kitaguchi, Masaaki*; Yamazaki, Dai; Ebisawa, Toru*; Soyama, Kazuhiko

中性子共鳴スピンエコー法は、中性子準弾性散乱を高いエネルギー分解能で測定できる分光法である。中性子のビーム発散によるフライトパス長のばらつきを楕円面ミラーにより補正することにより、中性子共鳴スピンエコー法の高エネルギー分解能化が実現される。この目的のための曲面スーパーミラーの開発状況及び中性子ビーム集光性能測定の結果について報告する。

Neutron resonance spin echo (NRSE) is one of the most useful techniques for quasi-elastic scattering with high energy resolution. The path length variation due to the beam divergence has to be corrected in high resolution NRSE measurement because it gives the limit in the energy resolution. A neutron focusing technique using neutron supermirrors is effective to overcome this problem. When a cylindrical shaped neutron supermirror placed in the center of the flight path with a pair of RSFs has the object and the image plane corresponding to the each coil plane of the first and the second RSF, the path length difference can be corrected for the neutron beam with large divergent angle, which leads to the realization of high intensity as well as high resolution in NRSE measurement. In this study, the correction method of the beam divergence with a cylindrical shaped supermirror and its experimental results are discussed.