2020同步年報

Facility Status 105 to form APXPS endstation I. This endstation will continue to be used mostly for gas-solid research but operating at a much greater pressure up to 100 mbar. APXPS endstation II at the end of this beamline will be designed to study the liquid-solid interface using the dip-and-pull method, espe- cially related to electrochemistry applications. The schemat- ic drawing of the beamline and the design drawing of the endstation are shown in Fig. 10 . TPS 47A High-resolution X-ray Absorption Spectroscopy Beamline High-energy-resolution hard-X-ray absorption spectroscopy (HER-XAS) and high-energy photoelectron emission spec- troscopy (HAXPES) are advanced and powerful techniques for the determination of valence state and local atomic electronic structure of absorbing atoms in materials, and have become popular and wide applications for experi- mental technology of synchrotron research. The evolution of the valence of a sample is crucial to a comprehensive understanding of dynamic processes with experimental conditions in situ/operando . For this purpose, TPS 47A High-resolution X-ray Absorption Spectroscopy Beamline is dedicated to nanomaterial research and next-genera- tion semiconductor development on applications in situ/ operando . Two experimental endstations—HER-XAS and HAXPES—are to be built and installed on this beamline. TPS 47A is a beamline with great brightness and high energy resolution using an undulator device and a high-resolution crystal monochromator, as well as also providing a small beam spot, less than 20 µm, in both endstations. The high- energy-resolution X-ray-absorption spectral measurements can provide more detailed information about electronic physics to environmental and biological science as well as industrial fields. The schematic drawing of the beamline and the design drawing of the endstation are shown in Fig. 9 . TPS 43A Ambient Pressure X-ray Photoelectron Spectroscopy Beamline Ultra-high vacuum (UHV) X-ray photoelectron spectros- copy (XPS) is a powerful tool for surface analysis and can be applied to study the chemical state and elemental composition of surface layers in solid samples. In contrast to a high-vacuum requirement of UHV-XPS, ambient pres- sure XPS (APXPS) can conduct a real-time investigation of gas-solid, liquid-solid and liquid-gas heterogeneous reac- tions at a pressure up to the mbar range. This capability allows researchers to study critical physical and chemical processes previously inaccessible in many research areas, including catalysis, energy storage and environmental science. Here we report a dedicated, high-photon-flux beamline for AP/UHV XPS experimental endstations at TPS 43A . The optical design of this beamline is based on an AM-PGM; the X-ray source is from an elliptically polarizing undulator with magnetic period 56 mm, which can pro- duce a photon flux greater than 10 12 photons·s -1 , in energy range 200 to 3000 eV with resolution power 10,000. Three experimental endstations arranged in tandem are to be installed in this beamline. The UHV-XPS endstation, located upstream, is sourced from an X-ray microbeam of area 10 (H) × 10 (V) µm 2 . This endstation will be dedicated to the conventional photoelectron spectroscopic investigation of micrometre-size solid samples. The existing APXPS endsta- tion at TLS 24A1 will be upgraded based on usage survey results and then moved to the middle endstation location Fig. 10 : Preliminary optical and endstation layout for TPS 43A .