The spectrum of F-center excitation by 5 to 27eV photons in this sodalite optical ceramic was measured at 80K by using high-sensitivity photo-excited luminescence techniques. The F centers were created by photons, with an energy of 5.6 to 8.5eV, via the excitation and ionization of I centers of 2 types. In the 8.2 to 27eV region, they were produced via the generation of electronic excitations in the aluminosilicate framework of alternating Al3+ and Si4+ ions; each of which was coordinated tetrahedrally with O ions. At these low irradiation doses, the F centers were created mainly via photo-electron capture by I vacancies which existed before irradiation. In the 23 to 25eV region, the efficiency of F-center formation doubled as a result of the multiplication of electron-hole pairs.

Color Center Formation by Synchrotron Radiation in Al6NaSi6O24(NaI)1.6  Optical Ceramic. I.Kudryatseva, P.Liblik, A.Lushchik, C.Lushchik, V.Nagirnyi, E.Vasilchenko: Fizika Tverdogo Tela, 2001, 43[5], 798-803 (Physics of the Solid State, 2001, 43[5], 830-5