Regular Article – Atomic Physics
Effect of quantum plasma on 2p photoionization cross section of ion embedded in shock compressed aluminium
Theoretical Physics Section, Bhabha Atomic Research Centre, 400085, Mumbai, India
Accepted: 12 December 2022
Published online: 7 January 2023
We studied the effect of plasma environment on the valence shell (2p) photoionization cross section of ions which are the most abundant charge species in shock compressed Al plasmas. The thermodynamic conditions achieved in these plasmas generally correspond to warm dense regime. The effect of plasma density and temperature on the atomic potential in warm dense regime can be modelled via short range quantum plasma (QP) potential. We employed QP potential to study photoionization cross section from 2p subshell of ions by solving the radial Schrodinger equation within the one-electron model potential framework. Bound and continuum states of the ion were altered in the presence of plasma environment, and consequently, significant changes in the photoionization cross section were observed. It was observed that near the ionization threshold, low energy scattering became dominant and lead to drastic reduction in the cross section satisfying Wigner threshold law. This is a general feature exhibited for any value of screening strength () of the plasma. However, in the vicinity of critical screening strength (), we observed resonance features at low photo electron energies. For , shape of the potential allowed formation of quasi-bound states which were responsible for trapping the photoelectron for a relatively longer time resulting in enhancement of the cross section termed ’shape resonance’. For , broad resonances, termed s-wave resonances, were observed. These resonances appear when near-zero energy photoelectrons get trapped in the bound s states which are on the verge of being pressure ionized.
© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.