Abstract
The decay processes of core-excitons in ionic crystals using synchrotron radiation are studied. Recently I have applied the photoelectron spectroscopy to Auger-free luminescence materials (CsCl and BaF 2 ). The decay probability of the core excitons in these materials, derived from the resonant photoemission data, is reported here. The comparison with the previous data on Li-1s core-excitons in Li-halides and Na-2p core-excitons in Na-halides is also presented. It is suggested that the lattice relaxation takes part in the core-exciton decay in most materials.