Intrinsic luminescence excitation spectra in NaCl, NaBr, RbCl and RbBr between 6 eV and 60 eV using synchrotron radiation

The excitation spectra for intrinsic luminescence due to recombination of self-trapped excitons at liquid helium temperature have been measured in NaCl, NaBr, RbCl and RbBr. The observed sequence of thresholds is explained in terms of multi-exciton production processes involving both valence and core excitons. Results are compared with published optical and photoelectron data and found to be in reasonable accord.