Angular distribution of photoelectrons ejected from HI by polarised coherent VUV radiation

Abstract
The asymmetry parameter beta of the photoelectron angular distribution of the process HI(5 pi 4) 1 Sigma + ( upsilon "=0)+hv to HI+(5 pi 3) 2 Pi 3/2 ( upsilon '=0)+e- was measured at photon energies from 86440 to 87000 cm-1. The data show resonance structure due to autoionisation that was not resolved before. The results are compared with predictions of an ab initio calculation by H Lefebvre-Brion and co-workers (1985).