The luminescence and excitation spectra of electronic excitations localized near a single anion vacancy (e,), a divacancy (ed), and a vacancy quartet (e,) are investigated. The shifts of spectral characteristics of these excitations with respect to those of the excitations in regular lattice sites (e,) have regular behavior. It turned out that the charge of vacancy defects is the main perturbing factor for e,, ed, and eq creation and the dimension of vacancy defects is the main perturbing factor for the radiative decay em, ed, and e,. The peculiarities of e,, ed, and e, relaxation are discussed in terms of strong and weak off-centers for e, in KBr and KI, respectively.') Riia 142, EE 2400 Tartu, Estonia. ' ) Pr. Moldagulovoi 34, 463 019 Aktyubinsk, Kazak.

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The cryostat 1 was worked out, helped to deform the crystals at 80 K with different degree of deformation and to register luminescence, absorption and thermally activated characteristics of crystals, also to record the ionic and thermally stimulated currents of the dipole defects of depolarization. The degree of crystals deformation is given by compressing screw pitch which is equal to 1mm at a complete revolution of the crystal holder. The construction of the cryostat allows to set experimentally the desired degree of crystals deformation. Deformation can be removed from the crystal and re-update at different temperatures.