Transition from Adiabatic to Sudden Core-Electron Excitation:N2on Ni(100)

Abstract
The first systematic study of the energy dependence of a core-level shake-up feature is presented. In contrast to expectations the shake-up peak remains nearly unchanged in intensity down to ∼ 15 eV above threshold. The early and abrupt turn-on of the multi-electron satellite found experimentally is well explained by a theory which describes the transition from adiabatic to sudden core-level excitation by a simple exchange-interaction picture.