KβX-Ray Emission andKX-Ray Absorption ofCl−in NaCl

The $K\beta$ emission and the $K$ absorption spectra of ${\mathrm{Cl}}^{-}$ ion in NaCl have been obtained with a 50-cm bent-quartz-crystal vacuum spectrograph. The obtained spectra are compared with the density of states calculated by Fong and Cohen and by Lipari and Kunz. The $K\beta$ satellites are accounted for in terms of the Deslattes model. A shoulder at the threshold of the $K$ absorption is observed for the first time and its origin is discussed in terms of the core exciton.