Development of a micro-region diffraction equipment by synchrotron microbeam

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A diffraction equipment for micro-region in a thin section has been developed by using polychromatic synchrotron radiation(SR). An imaging plate(IP;Fuji Co.,Ltd.) was employed for a detector.A software system has also been completed by changing the system developed previously for sub-micrometer-sized single crystal.Due to limited space around beamline 4B of the Photon Factory, KEK, Tsukuba, a micro-pinhole was used for making very fine incident SR.Since it is most important to achive a very low background level of the experiment, the equipment was placed in vacuum for avoiding air scattering. An IP readout-system was also installed in the vacuum chamber. Therefore, even though the equipment is placed in a vacuum chamber, a diffraction pattern of different region or at different crystal orientation can be obtained without opening the chamber.Micro-pinholes of 5 and 10mu m were made by ourselves and set just after a collimator. The distance between the pinhole and the thin section is 7mm, the detector covers -30 to 165 degrees in two-theta range with camera radius of 100mm.This apparatus with a 10mum pinhole was initially applied to olivine (Mg_2SiO_4) grains, considered as different origins, included in a thin section of meteorite, and also to micrometer-sized aluminum g rains on a semiconductor material. Each diffraction pattern of different olivine grains shows different X-ray diffraction profile according to its origin. An elongated diffraction pro-file of Al grain was observed together with sharp diffraction profile from Si(100) substrate in a case of the semiconductor.