2020同步年報

108 ACTIVITY REPORT 2020 Fig. 3 : Preliminary result for the pair distribution function of Si powder collected by MYTHEN 24K. sampling area, such as a diamond anvil cell, deposition-coating films, or mapping study of bulk specimens. For a high acquisition rate and micro- structure analysis such as crystalline orientation, graininess and texture, an area detector (Perkin Elmer, Varex Imaging, XRD 1611) was selected as the scanning detector on TPS 19A2 . This area detector provides a frame rate up to 15 frames per second and a Q coverage by 4096 x 4096 with pixel size 100 µm. In summary, TPS 19A2 offers the option of X-ray diffraction (XRD) measurements focusing on structure or phase evolu- tion with complicated setups in situ ; it could otherwise be used as rapid scanning before the high-resolution experiment at TPS 19A1 . Apart from a material system with long-range ordering, many materials show their practical and interesting physical properties because of the short range of their local structure; developing PDF and rapid PDF (rPDF) is hence our long-term project. The expected X-ray energy for PDF is 30 to 40 keV, for which the maximum Q range can attain 20–30 Å -1 . A prelim- inary PDF study for a NIST standard material, Si (640d), is shown in Fig. 3 , which was measured with a MYTHEN detector with X-rays of energy 20 keV. The rPDF is expected to be measured using a detector (2D XRD1611) with an integrated non-ambient system. Combining both high-resolution powder XRD and PDF techniques, TPS 19A provides a total solution for structure determina- tion. It is believed that the users will appreciate the beamline performance and create many scientific results in the near future. (Reported by Yu-Chun Chuang, Chung-Kai Chang and Bo-Hao Chen) References 1. J.-C. Huang, H. Kitamura, C.-S. Yang, C.-K. Yang, S. Mizumoto, C.-H. Chang, C.-H. Chang, C.-S. Hwang, AIP Conference Proceedings 2054 , 030022 (2019). 2. Y.-C. Chuang, NSRRC Activity Report 2016 , 85 (2017). 3. Y.-C. Chuang, C.-Y. Huang, J.-C. Huang, NSRRC Activity Report 2018 , 100 (2019).