Quality of the YB66 crystal of BL15XU at SPring-8

The quality of the YB66 crystal was investigated by rocking curve measurements using a conventional X-ray source and the synchrotron radiation of BL15XU at SPring-8 before and after the irradiation with synchrotron radiation. It is confirmed by evaluating the full-width at half-maximum of rocking curve and by the Lang topographic method that the YB66 crystal has a nonuniform quality and distribution of energy resolution, and that density of dislocations and subgrain boundary structures depended on the position of the crystal, as reported previously. A significant change in the quality of the YB66 crystal was not observed between before and after irradiation of synchrotron radiation. The qualities of single YB66 crystals are sufficiently good to maintain a high resolution for dispersing synchrotron radiation at power density and power of not more than 1.7 W/mm2 and 0.13 W, respectively, for about 1000 h at the third-generation light source SPring-8. rmore, reactivity of YB66 crystal with GaIn was studied by SEM, EDX in the laboratory and by a transmission function of synchrotron radiation dispersed by a YB66 (4 0 0) double-crystal monochromator in the beam study of BL15XU. From these experiments, it is concluded that the reaction of YB66 crystal with GaIn does not occur. Thus, GaIn as an interface material between a YB66 crystal and a Cu holder coated with Ni is available for an indirect cooling system of BL15XU at SPring-8.