Precision measurements of the absolute photoionization cross sections of He

Abstract

Precision photoionization cross sections for He have been measured from threshold to 120 eV with an accuracy ranging from 1 to 2%. In addition, a critical review of the published data has been made and recommended photoionization cross sections from the ionization threshold to 8 keV are presented with an estimated uncertainty of +or-10% above 500 eV. The effect of coherent (Rayleigh) and incoherent (Compton) scattering is discussed.