2020同步年報

Facility Status 103 Fig. 7 : Optical layout of TPS 33A Dragon Beamline. magnetic materials and energy materials. The energy range of the TPS Dragon Beamline is focused on 90–3000 eV. For quick polarization switching, we use an orbital-bump scheme; the source includes two EPU66, a fast kicker system and a phase corrector at a long straight section of TPS. The total length of the beamline is about 44 m from the center of the straight section to the sample position. The photon flux at the sample position is required to be more than 1 × 10 12 photons·s -1 with energy resolving power 20,000. The beam size at the sample position is required to be about 10 × 10 µm 2 at both branches. The key part of this beamline is a novel design of monochromator system—the active-mirror and plane-grating monochromator (AM-PGM). This design lets us have a capability to perform parallel detection in transmission or reflection XAS and MCD at endstation-I. Endstations-II and -III are for high-magnetic-field magnetic circular dichroism (HF-MCD) and in-situ/operando XAS, respectively . The schematic drawing of the beamline is shown in Fig. 7 . TPS 35A Soft X-ray Absorption Spectroscopy Beamline Soft XAS performed at a synchrotron light source with in- tense and tunable X-ray beams is well known as a powerful tool to determine the electronic structures, such as valence state, spin state and site symmetry of the element-specific absorbing atoms of materials by exciting electrons in a rel- atively shallow core layer into unoccupied energy levels or unbound continuum states. The soft XAS technique at TPS 35A beamline operating in photon energy range 100−3000 eV enables one to probe broad elements such as the 3d-transition-metal (L 2,3 -edge spectrum), rare-earth (M 4,5 - edge spectrum) and ligand elements (K-edge spectrum) such as carbon, nitrogen, oxygen, fluorine, phosphorus, sulfur, which are commonly observed in diverse practical or potential applications such as a two-dimensional semicon- ductor, superconductivity, pyroelectricity, giant magnetore- sistance, magneto-optical, semi-metal, electro- or photo- catalysis, lithium-ion battery (LIB) and other characteristics. Endstation TPS 35A will also provide new scientific oppor- tunities for the investigation of the interfacial phenomena occurring in the electrode/electrolyte of a LIB, and hydro- gen evolution/oxidation, oxygen evolution/reduction, car- bon dioxide reduction of electro- (or photo)-catalysis mate- rials, respectively, which have received enormous attention in recent years because of the development of SiN-window- sealed liquid (or gas) cell system. Beamline TPS 35A at TPS utilizes the light generated from an elliptically polarized undulator (EPU) with a rapid energy-scanning-speed 50 eV/20 s by continuously varying the undulator gap with the minimum gap 15.0 mm and switching among the harmonics number 1–5. The estimated photon flux on the sample with maximum 3.6 × 10 12 photons·s -1 · (0.1% bw) -1 and beam size ~100 × 100 μm 2 can be obtained based on an optimized design of beamline optics as shown in Fig. 8 . Endstation TPS 35A as shown in Fig. 8 enables collection of partial/total electron-yield and fluorescence-yield X-ray absorption spectra to probe a material at varied depth from the surface state (~1 nm) to the near-surface state (~5 nm) and to the bulk state (~100 nm), which will be available to meet the demands of all users in exploring the properties of materials in a wide range of disciplines. TPS 38A X-ray Absorption Spectroscopy Beamline There are at present four XAS beamlines ( TLS 01C1 , TLS 07A1 , TLS 16A1 , and TLS 17C1 ) at TLS and one quick- scanning X-ray absorption spectroscopy (QXAS) beamline ( TPS 44A ) at TPS. In the TPS Phase-III project, we plan to build a new beamline at bending magnet port #38. This beamline TPS 38A is designed to cover an energy range