  We demonstrate strong interference patterns in the photoionization
cross-section of the subvalent subshells of noble gas (NG) endohedral atoms
NG@F. This interference is a result of common action of three factors: the
effect of neighboring atomic subshells, reflection of photoelectron waves by
the fullerene F shell and resonance modification of the incoming photon beam by
the complex effect under the action of the F electrons.
  We have considered the outer ns-subshells for Ne, Ar, Kr and Xe noble gas
atoms. The polarization of the fullerene shell is expressed via the F total
photoabsorption cross section. The photoelectron reflection from the static F
potential is taken into account in the frame of the so-called bubble potential
that is a spherical zero--thickness type potential.
  It is assumed in the derivations that NG is centrally located in the
fullerene. It is assumed also, in accordance with the available experimental
data, that the fullerene radius is much bigger than the atomic radius and the
thickness of the fullerene shell. These assumptions permit, as demonstrated
recently, the NG@F photoionization cross section to be presented as a product
of the NG subvalent cross section and two calculated factors that account for
polarization of the F electron shell and reflection of photoelectrons by the
fullerene static potential.

Atomic and Molecular Clusters;Atomic Physics