TY  - JOUR
AU  - Wilson, Daniel Julian Arthur
AU  - Schmitz, Christoph
AU  - Rudolf, Denis
AU  - Wiemann, Carsten
AU  - Schneider, Claus M
AU  - Juschkin, Larissa
TI  - On space charge effects in laboratory-based photoemission electron microscopy using compact gas discharge extreme ultraviolet sources
JO  - New journal of physics
VL  - 22
SN  - 1367-2630
CY  - [London]
PB  - IOP
M1  - FZJ-2020-03279
SP  - 103019
PY  - 2020
AB  - The analysis of electronic and structural properties of surfaces has been greatly advanced by photoemission electron microscopy and spectroscopy techniques. To further improve lateral and energy resolution of the instruments, it is necessary to optimize parameters of the radiation sources employed for photoemission studies (e.g. photon flux, pulse duration, spot size etc.). We studied space charge effects observed in an energy-filtering photoemission electron microscope operated with a compact laboratory-scale gas-discharge extreme ultraviolet light source. In this system, we found limits of spatial- and energy-resolution controlled by the source radiation parameters. The pulse repetition rate can be varied in the kHz range and the duration of the EUV emission was measured to be several tens of nanoseconds long, and thereby very different from the standard synchrotron sources typically used for similar experiments. The spatial resolution could be improved by a factor of 5, but only on the expense of the photon density per pulse, which had to be decreased by a factor of 17 in order to reduce the image blur due to space charge effects. Furthermore, we found broadening of the X-ray photoelectron spectroscopy peaks for high photon fluxes. We have also performed a n-body Monte Carlo simulation to evaluate the difference between core-level photoelectrons and secondary electrons with respect to space charge.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000578365400001
DO  - DOI:10.1088/1367-2630/abbc29
UR  - https://juser.fz-juelich.de/record/884824
ER  -