Spectral-kinetic investigation of the excitation spectra of intrinsic and impurity emissions hav been carried out for KI and MgO crystals by means of the synchrotron radiation of 6-35 eV at 5-10 K. In KI, we succeeded in separating the cration processes of secondary excitons and electron-hole paris in the region of 13-17 eV. TShe applied elastic uniaxial stress enhances the probability of 13-17 eV. The applied elastic uniaxial stress enhances the probability o f the self-trapping of excitons and decreases the migration of excitons to impurity centers in KI. The possibility to control the relaxation of holes at the unaxial stress of a crystal is discussed. The excitation spectra of 7.63 and 6.85 eV emissions, that correspond to the large-and small-radius electronic excitations localized near Ca~(2+), have been measured in a MgO:Ca crystal. The efficiency of these emissions, as well as of free exiton emission in MgO, sharply increases at 21-35 eV, where the absorption of one photon causes the formation of two or three electronic excitations.
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