Abstract:
Beamline 47A at the Taiwan Photon Source (TPS) is a newly commissioned hard X-ray beamline dedicated to high-resolution X-ray spectroscopy. The beamline features two complementary endstations: Endstation 1 for photon-in/photon-out spectroscopy and Endstation 2 for hard X-ray photoelectron spectroscopy (HAXPES). Its optical layout incorporates a cryogenically cooled Si(111)/Si(311) double-crystal monochromator and a four-bounce high-resolution monochromator (HRM) with selectable Si(333) and Si(400) reflections.
The HRM reduces the incident bandwidth to below 100 meV, enhancing energy resolution and sensitivity to weak spectral features. Combined with a 1 m-radius Johann spectrometer at Endstation 1, the beamline enables sub-eV resolution XES, HERFD-XAS, and RIXS measurements across a broad hard X-ray energy range.
The high energy resolution significantly improves the capability of HERFD-XAS by suppressing core-hole lifetime broadening, while XES provides element-selective information on the occupied electronic states and local chemical bonding. Together, these complementary techniques enable detailed investigations of oxidation states, spin configurations, metal–ligand interactions, and electronic structure evolution under operando conditions.
Designed for both performance and flexibility, Beamline 47A provides configurable monochromator and analyzer optics to support a broad range of experiments on functional materials, transition-metal compounds, catalytic systems, and correlated electron systems.
Keywords – HERFD-XAS ,RIXS XES