Electron spectroscopy and dynamics of HBr around the Br 1sā1 threshold†
Abstract
A comprehensive electron spectroscopic study combined with partial electron yield measurements around the Br 1s ionization threshold of HBr at ā 13.482 keV is reported. In detail, the Br 1sā1 X-ray absorption spectrum, the 1sā1 photoelectron spectrum as well as the normal and resonant KLL Auger spectra are presented. Moreover, the L-shell Auger spectra measured with photon energies below and above the Br 1sā1 ionization energy as well as on top of the Br 1sā1Ļ* resonance are shown. The latter two Auger spectra represent the second step of the decay cascade subsequent to producing a Br 1sā1 core hole. The measurements provide information on the electron and nuclear dynamics of deep core-excited states of HBr on the femtosecond timescale. From the different spectra the lifetime broadening of the Br 1sā1 single core-hole state as well as of the Br(2sā2,2sā12pā1,2pā2)Ā double core-hole states are extracted and discussed. The slope of the strongly dissociative HBr 2pā2Ļ* potential energy curve is found to be about ā13.60 eV Ć ā1. The interpretation of the experimental data, and in particular the assignment of the spectral features in the KLL and L-shell Auger spectra, is supported by relativistic calculations for HBr molecule and atomic Br.
- This article is part of the themed collection: 2020 PCCP HOT Articles