On the photoionization of the outer electrons in noble gas endohedral atoms

TL;DR

This paper investigates how the photoionization cross-section of noble gas atoms inside fullerenes is significantly modified by the fullerene shell, showing enhancement and oscillations due to polarization and electron reflection effects.

Contribution

It introduces a model that accounts for shell polarization and electron reflection, providing a new way to analyze photoionization in noble gas endohedral atoms.

Findings

Significant enhancement of photoionization cross-section due to fullerene shell polarization.

Pronounced oscillations in cross-section caused by photoelectron reflection.

Theoretical framework applicable to all noble gases except helium.

Abstract

We demonstrate the prominent modification of the outer shell photoionization cross-section in noble gas (NG) endohedral atoms NG@F under the action of the fullerene F electron shell. This shell leads to two important effects, namely to strong enhancement of the cross-section due to fullerenes shell polarization under the action of the incoming electromagnetic wave and to prominent oscillation of this cross-section due to the reflection of the photoelectron from NG by the F shell. All but He noble gas atoms are considered. The polarization of the fullerene shell is expressed via the total photoabsorption cross-section of F. The reflection of the photoelectron is taken into account in the frame of the so-called bubble potential that is a spherical zero --thickness potential. It is assumed in the derivations that NG is centrally located in the fullerene. It is assumed also, in accord with the existing experimental data, that the fullerenes radius R is much bigger than the atomic radius and the thickness of the fullerenes shell . These assumptions permit, as it was demonstrated recently, to present the NG@F photoionization cross-section as a product of the NG cross-section and two well defined calculated factors.