The spectrum of F-center creation was measured in Tl-doped material by means of synchrotron radiation (12 to 24eV) after exposure to vacuum ultra-violet light. Analysis of the spectrum revealed a decay of cation excitons (19.7 to 20.3eV), with the formation of a double number of electron-hole pairs. The creation efficiency of stable F-centers was especially high at 15 to 17eV, where the absorption of one photon led to the formation of both an electron-hole pair and an exciton. In this case, there were favorable conditions for the stabilization of mobile radiation defects; due to the association of interstitial halogen atoms, holes, and cation vacancies.

A.Lushchik, I.Kudrjavtseva, C.Lushchik, E.Vasilchenko, M.Kirm, I.Martinson: Physical Review B, 1995, 52[14], 10069-72