The Novel measuring method in inelastic region; RRM planned for the backscattering spectrometer DNA at the MLF, J-PARC

J-PARC MLFの背面反射型分光器DNAで計画されている、非弾性領域の新規測定手法; RRM法

高橋 伸明; 柴田 薫*; 川北 至信  ; 蒲沢 和也*; 山田 武*; 中島 健次   ; 稲村 泰弘  ; 中谷 健 ; Mezei, F.*; Neumann, D.*; 新井 正敏

Takahashi, Nobuaki; Shibata, Kaoru*; Kawakita, Yukinobu; Kamazawa, Kazuya*; Yamada, Takeshi*; Nakajima, Kenji; Inamura, Yasuhiro; Nakatani, Takeshi; Mezei, F.*; Neumann, D.*; Arai, Masatoshi

A Si-analyzer neutron backscattering spectrometer, DNA, in MLF is the first indirect geometry instrument which chooses the coupled moderator as a pulsed neutron source in addition with a high speed disc chopper as a pulse-shaping device, aiming for high energy resolution with high intensity. The pulse-shaping has the advantage of obtaining a variety of slit opening times. On the other hand, it has the disadvantage of limiting the wavelength band width measured within one pulse-shaped neutron beam. This disadvantage is solved by employing 4 slit discs on the pulse-shaping chopper and generating multiple pulse-shaped incident beams to realize efficient measuring, the so called Repetition Rate Multiplication: RRM technique. An automatic phasing procedure for this RRM technique is planned.