Angle‐resolved photoelectron spectroscopy of HCl from a photon energy of 16 to 80 eV

Angle‐resolved photoelectron spectroscopy was performed on HCl using synchrotron radiation over a photon energy from 16 to 80 eV. The partial cross sections and angular distribution parameters β were obtained for photoionization of both the 2π and 5σ orbitals. Multiple scattering Xα calculations were also carried out for the cross sections and β values. The calculations, together with previously published results on the cross section using a Hartree–Fock model, were compared with experiment and gave reasonable qualitative agreement. Both experimental and theoretical results were examined with particular regard to the nature of the Cooper minimum, and the differences between the behavior of the minima for the two orbitals are discussed in detail.