Photoionization of onion-type atoms

The photoionization of a two-shell (“onion“) endohedral A@CN1@CN2 is considered. The effect of the fullerenes shells upon photoelectron from atom A is taken into account substituting the action of the fullerene by two zero-thickness “bubble potentials.“ The fullerenes shells polarization is included assuming that the radius of the outer shell R2 is much bigger than the inner R1 and both much exceed the atomic radius r. The interaction between shells CN1 and CN2 is taken into account in the Random Phase Approximation (RPA). The effect of photoelectron scattering by both “bubble potentials“ is included in the RPA frame. As concrete examples, two endohedrals Ar@C60@C240 and Xe@C60@C240 are considered. We investigate 3p4 Ar and 5p Xe subshells.