Time-resolved high energy ionoluminescence of Al2O3

Abstract

We have compared the luminescence decay from intact and pre-damaged Al2O3 crystals registered during single swift heavy ion and photo- picosecond laser pulse excitation (λex. = 440 nm). The decay curves measured during 1.2 ÷ 1.6 MeV/amu C, Ar, V, Kr, Xe ion irradiation at room temperature are composed of three components – fast (τ1 < 1 ns), τ2 = 1.8 ns (F+-centers) and τ3 = 54–80 ns (E-luminescence, the nature of emission is under discussion). The measurements performed on pre-irradiated samples have demonstrated that accumulated radiation damage suppresses the E-luminescence and only τ1 and τ2 components are observed.It was found that photoexcitation at 440 nm induces strong emission of F22+- centers with a lifetime of about 8 ns which is not detected during high energy ion irradiation. This is ascribed to the quenching effect of high density excitations in a particle track.