Photoelectron satellite spectroscopy and angular distribution of argon atoms using a monochromatic EUV source based on high-order harmonic generation

Abstract

Photoelectron satellite spectra and angular distribution of argon atoms were measured in the energy range of 34--43 eV, using a well-developed reaction microscope mounted on a newly built high-order harmonic generation (HHG) extreme ultraviolet (EUV) source. Various satellites were resolved and the angular distribution asymmetry parameters $\ensuremath{\beta}$ were determined for both the main lines and the satellites. It is found that our measured $\ensuremath{\beta}$ for the $3p$ and $3s$ main lines are in an excellent agreement with previous results. The $\ensuremath{\beta}$ parameters measured for most of the satellites are first reported in this energy range, providing benchmark data for testing different theoretical models.