Current status of IBARAKI biological diffractometer in J-PARC; Optimization of design parameters

Kusaka, Katsuhiro; Ohara, Takashi   ; Tanaka, Ichiro*; Niimura, Nobuo*; Kurihara, Kazuo; Hosoya, Takaaki; Ozeki, Tomoji*; Aizawa, Kazuya  ; Morii, Yukio; Arai, Masatoshi; Hayashi, Makoto*; Ebata, Kazuhiro*; Takano, Yoshiki*

Ibaraki prefecture has started to construct IBARAKI biological crystal diffractometer for industrial use at MLF, J-PARC. It is designed to achieve the efficiency which is more than 50 times larger than the present high performance diffractometer BIX-4. To realize this performance, the diffractometer will be installed on a coupled moderator has more intense peak but wider pulse shape than a decoupled one. It is expected that some neighbor Bragg spots will overlap partially each other along the time axis. The overlapping of Bragg spots should be considered for optimization of design parameters and it is necessary to de-convolute the overlapped spots. The three original simulation programs of TOF diffraction data with designed parameters of the diffractometer were developed to obtain information of spot-overlapping, completeness of Bragg spots and spot profiles along the time axis. The consideration of important designed parameters will be reported based on the simulation results.