The quenching mechanisms of fast luminescence in crystals were studied by means of time-resolved vacuum ultra-violet spectroscopy, using synchrotron radiation. The luminescence decay of these crystals revealed at least 3 quenching mechanisms. One was usual for the vacuum ultra-violet region, where the radiation penetration depth was about 10nm, and resulted from surface losses. A second one was due to energy transfer to defect centers in the crystal bulk, and was very marked in CeF3-LaF3. The third, and least-studied, one was attributed to the interaction of closely-spaced electron excitations (secondary-electron excitation quenching). The temperature and energy dependences of the decay kinetics clearly indicated that the third quenching mechanism operated above the energy which corresponded to the creation threshold for secondary-electron excitations.

M.A.Terekhin, I.A.Kamenskikh, V.N.Makhov, V.A.Kozlov, I.H.Munro, D.A.Shaw, C.M.Gregory, M.A.Hayes: Journal of Physics - Condensed Matter, 1996, 8[4], 497-504