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arXiv · 2501.00188

Development of a linac-based LEPD experimental station for surface structure analysis and coordination with synchrotron radiation ARPES

Rezwan Ahmed·Izumi Mochizuki·Toshio Hyodo·Tetsuroh Shirasawa·Seigi Mizuno·Yoshinari Kondo·Kenichi Ozawa·Miho Kitamura·Kenta Amemiya·Bartlomiej Checinski·Jozef Ociepa·Achim Czasch·Ottmar Jagutzki·Ken Wada
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Abstract

We report on the development of a low-energy positron diffraction (LEPD) experimental station for surface structure analysis using a linac-based slow-positron beam. LEPD, the positron counterpart of low-energy electron diffraction (LEED), offers higher accuracy in surface structure determination. The station enables acquisition of LEPD I-V curves within a few hours, allowing measurements before surface degradation occurs. It consists of two ultra-high vacuum (UHV) chambers: one for sample preparation and the other for LEPD observations. The preparation chamber includes an Ar+ sputtering system, a triple-pocket electron beam evaporator, three gas introduction systems, additional user-configurable ports, and a LEED/Auger electron spectroscopy (AES) system. Sample manipulators enable rapid cooling, precise positioning, and orientation adjustments. In the preparation chamber, the manipulator also supports direct current heating up to 1200 {\deg}C. The sample holder is compatible with the LEPD station at SPF-A4 and the ARPES station at PF BL-13B, both located at the Tsukuba campus of the Institute of Materials Structure Science (IMSS), KEK. Design concepts and experimental demonstrations are presented.

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Rezwan Ahmed, Izumi Mochizuki, Toshio Hyodo, Tetsuroh Shirasawa, Seigi Mizuno, Yoshinari Kondo, Kenichi Ozawa, Miho Kitamura, Kenta Amemiya, Bartlomiej Checinski, Jozef Ociepa, Achim Czasch, Ottmar Jagutzki, Ken Wada. 2024-12-30. Development of a linac-based LEPD experimental station for surface structure analysis and coordination with synchrotron radiation ARPES. https://arxiv.org/abs/2501.00188

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