On the strong influence of inner shell resonances upon the outer shell photoionization of endohedral atoms

Abstract

It is demonstrated by the example of the Xe atom stuffed inside the C60 fullerene, i.e., the endohedral Xe@C60, that the so-called confinement resonances in 4d subshell strongly affect the photoionization cross section of outer 5p and subvalent 5s electrons near the 4d ionization threshold. It is a surprise that these narrow inner 4d shell resonances are not smeared out in the outer shell photoionization cross section. On the contrary; the inner shell resonances affect the outer cross section by enhancing them enormously. Close to its own photoionization thresholds, 5p and 5s photoionization cross sections of Xe@C60 are dominated by their own confinement resonances greatly affected by the amplification of the incoming radiation intensity due to polarization by it of the C60 electron shell. Between 4d and 5p thresholds, the effect of 4d is becoming stronger while own resonances of 5p and 5s are becoming much less important.