Non-dipole effects in two-photon sweeping of the K-shell of an atomic ion

TL;DR

This paper investigates non-dipole effects in two-photon ionization of atomic ions, revealing that these effects significantly reduce the cross-sections compared to dipole approximation predictions, with implications for atomic physics models.

Contribution

It introduces the first theoretical analysis of non-dipole effects in two-photon K-shell ionization of atomic ions, extending previous dipole approximation models.

Findings

Non-dipole effects significantly decrease cross-sections.

Giant non-dipole effect observed in Fe16+ ion.

Results challenge the validity of dipole approximation in this context.

Abstract

In the work [1], within the framework of a dipole approximation for the radiation transition operator, of the second-order nonrelativistic quantum perturbation theory and the Hartree-Fock single-configuration approximation, the first theoretical study of the generalized cross-section of the direct two-photon sweeping out of the K-shell of a light neon atom was carried out. In this Letter we supplement the Preprint [2] with the results of taking into account non-dipole effects when constructing the amplitude of the probability of the radiation transition between continuum-spectrum states. As the main result, it was found that the non-dipole effects reduce the generalized cross-sections of two-photon sweeping out of the K-shell of an atomic ion (Fe16+) the calculated in the dipole approximation by several orders of magnitude (giant non-dipole effect).