Development of low temperature 2-axes goniometer system for single crystal ToF Laue diffractometer SENJU

Kaneko, Koji   ; Munakata, Koji*; Dohi, Yuki*; Noda, Yukio; Hanashima, Takayasu*; Sato, Kaoru*; Kawasaki, Takuro   ; Kiyanagi, Ryoji  ; Nakao, Akiko*; Ohara, Takashi   ; Oikawa, Kenichi   ; Tamura, Itaru  

Recent technical development in piezo devices offers a possibility to move a crystal even at dilution temperature. We tried to develop a piezo-based goniometer in time with the construction of single crystal time-of-flight neutron Laue diffractometer SENJU at BL18 of J-PARC. The goniometer consists of two rotatable axes and with fixed- (45)to cover entire reciprocal space. A goniometer is directly mounted onto the cold finger of the standard closed-circle refrigerator. So far, sample rotation can be realised at base temperature of 4.4 K with reasonable cooling time of roughly 5 hours. In fact, several low temperature experiments using this goniometer have been worked out. Further efforts to improve base temperature, cooling time and accuracy of movements are in progress.