Applied Science and Convergence Technology
Published online April 1, 2022
Copyright © The Korean Vacuum Society.
Hyun-Joon Shin 1* , Jinjoo Ko 2 , Seunghwan Shin 2
1Chungbuk National University, 2Pohang Accelerator Laboratory
In Korea, a fourth-generation light source(Korea-4GLS), with 4-GeV electron energy, 58-pm-rad electron emittance, and 400-mA electron current, is currently under construction at Ochang. Compared to the light source at Pohang(Pohang Light Source: PLS-II), we describe advantageous features of the Korea-4GLS, considering geometry of probing techniques and application materials. In the case of probing laterally homogeneous specimens where X-ray size can be in the range of 10um–1mm and the sample is larger than X-ray size, X-ray scattering, absorption and photoelectron spectroscopy techniques are improved when the flux increases. In this case, the Korea-4GLS is better than the PLS-II in the energy range of 1–2.5keV(higher energy side for soft-X-ray-based techniques), 2–4keV(medium energy-based techniques), and 10–100keV(higher energy side for hard-X-ray-based techniques). In the case of probing laterally inhomogeneous specimens where X-rays are to be focused below 1um, nano-probe and spectro-nanoscopy techniques, such as coherent diffraction imaging, ptychography, scanning transmission X-ray microscopy, or photoelectron microscopy take advantage of the brilliance increase. In this case, nano-probe and spectro-nanoscopy techniques take advantage of all energy ranges, especially soft X-ray spectro-nanoscopes (better than 100-times gain), which require an exit slit as a virtual source for the nanoscope.
Keywords: fourth generation light source, Korea-4GLS, nanoprobe, spectro-nanoscopy, brilliance, Ochang Light Source