Monochromatic neutron diffractometers for protein crystallography at present and in the future in Japan

栗原 和男*; 河野 史明*; 清水 瑠美*; 田村 格良  ; 大原 高志   ; 茶竹 俊行*; 井上 倫太郎*; 平野 優*; 玉田 太郎*

Kurihara, Kazuo*; Kono, Fumiaki*; Shimizu, Rumi*; Tamura, Itaru; Ohara, Takashi; Chatake, Toshiyuki*; Inoue, Rintaro*; Hirano, Yu*; Tamada, Taro*

In Japan, two protein diffractometers using monochromatic neutron beams, BIX-3 and BIX-4, are operated in the research reactor, JRR-3. The BIX-3 uses thermal neutrons and is equipped with a double-bunk monochromator system where Si (111) and Si (311) monochromators are arrayed at the bottom and top bunk, respectively. This system contributed to the successful determination of a protein structure with sub-angstrom resolution. The BIX-4 uses cold neutrons and is equipped with a variable wavelength selection system suitable for use with an optimal wavelength depending on crystal quality and/or lattice length. This talk will also present a brief introduction to a plan to install new diffractometers in a new research reactor to be constructed at the "Monju" site.