Equal energy-sharing double photoionization of helium from near-threshold to high energies

Abstract

For a given excess energy E above the helium double photoionization (DPI) threshold, just two parameters are necessary to generate any angular set of the fully resolved triply differential cross sections (TDCS) in the case of the two outgoing electrons sharing E equally. It is shown that these parameters, the width and magnitude of the Gaussian ansatz, may be estimated ab initio from the convergent close-coupling (CCC) theory. The CCC calculations have been performed for E in the range of 3--80 eV, allowing for the generation of equal energy-sharing TDCS at arbitrary orientation of the two electrons and polarization of the photons.