The capabilities and opportunities of a new soft X-ray photon-in/electron out microscope at the Taiwan Photon Source
Tzu-Hung Chuang1*, Hung-Wei Shiu1, Chia-Hao Chen1, Yao-Jane Hsu1, Der-Hsin Wei1
1Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
* Presenter:Tzu-Hung Chuang,
The Photoelectron Related Image and Nano-Spectroscopy (PRINS) end-station at the Taiwan Photon Source (TPS) 27A2 will host a photoelectron microscope that aims to work on photoelectron-related imaging and nano-scale spectroscopy through the combination of an imaging-type electron column integrated with a hemispherical electron energy analyzer and an imaging spin filter. The microscope is able to conduct full-field imaging by collecting photoelectrons in either real-space or momentum-space with spin contrast.
Taking advantage of an elliptically polarized undulator (EPU) photon source, i.e. the energy and polarization of the X-rays are both tunable, and powering by an in-house designed active-mirror plane grating monochromator, which delivers soft X-rays in a range of 90-3000 eV, the PRINS microscope has multiple capabilities, such as (1) X-ray absorption spectroscopy (XAS)-based and X-ray magnetic circular dichroism (XMCD)-based real-space imaging to obtain element-resolved mapping or spin-texture information, (2) X-ray photoelectron spectroscopy (XPS)-based real- and momentum-space imaging to obtain spatially-resolved chemical state mapping and band-structure imaging, (3) spin-resolved band structure measurement when the imaging spin filter is introduced, and (4) micro-area spectroscopy (XAS, XPS, and angle-resolved photoelectron spectroscopy) extracted from a series of images measured at different kinetic energies of the electrons.
The photoelectron microscope system including a hexapod sample manipulator, imaging spin filter, and ultraviolet light sources (mercury and helium) is expected to arrive at TPS before June 2021. A sample preparation chamber with standard surface science characterization capabilities, including the ion sputtering, low energy electron diffraction, Auger electron spectroscopy, and electron-assisted thin-film deposition, will be connected to the main photoelectron microscope system to enable in-situ experiments. The sample preparation system will be initiated and tested at the beginning of 2021. Technical capabilities and scientific opportunities of the end-station will be discussed in the talk, and the current status will also be reported.

Keywords: photoemission electron microscopy, 2D materials, momentum microscopy, imaging spin filter, X-ray photoelectron spectroscopy