Ohhara Takashi, Kiyanagi Ryoji, Oikawa Kenichi, Kaneko Koji, Kawasaki Takuro, Tamura Itaru, Nakao Akiko, Hanashima Takayasu, Munakata Koji, Moyoshi Taketo, Kuroda Tetsuya, Kimura Hiroyuki, Sakakura Terutoshi, Lee Chang-Hee, Takahashi Miwako, Ohshima Ken-Ichi, Kiyotani Tamiko, Noda Yukio, Arai Masatoshi
Neutron Science Section, J-PARC Center, Japan Atomic Energy Agency , 2-4 Shirakata, Tokai, Ibaraki 319-1195, Japan.
Research Center for Neutron Science and Technology, Comprehensive Research Organization for Science and Society , IQBRC Building, 162-1 Shirakata, Tokai, Ibaraki 319-1106, Japan.
J Appl Crystallogr. 2016 Feb 1;49(Pt 1):120-127. doi: 10.1107/S1600576715022943.
SENJU is a new single-crystal time-of-flight neutron diffractometer installed at BL18 at the Materials and Life Science Experimental Facility of the Japan Accelerator Research Complex (J-PARC). The diffractometer was designed for precise crystal and magnetic structure analyses under multiple extreme sample environments such as low temperature, high pressure and high magnetic field, and for diffraction measurements of small single crystals down to 0.1 mm in volume. SENJU comprises three choppers, an elliptical shape straight supermirror guide, a vacuum sample chamber and 37 scintillator area detectors. The moderator-to-sample distance is 34.8 m, and the sample-to-detector distance is 800 mm. The wavelength of incident neutrons is 0.4-4.4 Å (first frame). Because short-wavelength neutrons are available and the large solid angle around the sample position is covered by the area detectors, a large reciprocal space can be simultaneously measured. Furthermore, the vacuum sample chamber and collimator have been designed to produce a very low background level. Thus, the measurement of a small single crystal is possible. As sample environment devices, a newly developed cryostat with a two-axis (ω and φ axes) goniometer and some extreme environment devices, a vertical-field magnet, high-temperature furnace and high-pressure cell, are available. The structure analysis of a sub-millimetre size (0.1 mm) single organic crystal, taurine, and a magnetic structure analysis of the antiferromagnetic phase of MnF have been performed. These results demonstrate that SENJU can be a powerful tool to promote materials science research.
SENJU是一台新的单晶飞行时间中子衍射仪，安装在日本质子加速器研究中心（J-PARC）材料与生命科学实验设施的BL18处。该衍射仪旨在用于在低温、高压和强磁场等多种极端样品环境下进行精确的晶体和磁性结构分析，以及对体积小至0.1 mm的小单晶进行衍射测量。SENJU由三个斩波器、一个椭圆形直超镜导向器、一个真空样品室和37个闪烁体面积探测器组成。慢化剂到样品的距离为34.8 m，样品到探测器的距离为800 mm。入射中子的波长为0.4 - 4.4 Å（第一帧）。由于可以获得短波长中子，并且样品位置周围的大立体角被面积探测器覆盖，因此可以同时测量大的倒易空间。此外，真空样品室和准直器的设计使得背景水平非常低。因此，可以对小单晶进行测量。作为样品环境装置，可以使用新开发的带有双轴（ω和φ轴）测角仪的低温恒温器以及一些极端环境装置，如垂直场磁体、高温炉和高压池。已经对亚毫米尺寸（0.1 mm）的单有机晶体牛磺酸进行了结构分析，并对MnF的反铁磁相进行了磁性结构分析。这些结果表明，SENJU可以成为推动材料科学研究的有力工具。
