Total quadruple photoionization cross section of Beryllium in a quasiclassical framework

TL;DR

This paper develops a quasiclassical approach to calculate the total quadruple photoionization cross section of Beryllium, providing insights into electron escape behavior and energy dependence up to 620 eV.

Contribution

It introduces a novel quasiclassical framework for modeling quadruple ionization in a five-body Coulomb system, aligning well with threshold laws and shape formulas.

Findings

Results agree with Wannier threshold law near threshold.

Total cross section shape matches a theoretical shape formula.

Maximum cross section energy follows a linear relation with ionization threshold.

Abstract

In a quasiclassical framework, we formulate the quadruple ionization by single photon absorption of the Coulomb five-body problem. We present the quadruple photoionization total cross section of the ground state of Beryllium for energies up to 620 eV. Our quasiclassical results for energies close to threshold are in agreement with the Wannier threshold law for four electron escape. In addition, the agreement of our results with a shape formula provides support for the overall shape of our total quadruple cross section. Finally, we find that the photon energy where the maximum of the total photoionization cross section occurs for single, double, triple and quadruple photoionization of H, He, Li and Be, respectively, seems to follow a linear relation with the threshold energy for complete break-up of the respective element.