Luminescence centers induced by UV irradiation on γ-Al2O3 surface are affected by O2 (rather than H2) admission both before and after irradiation. Excitation and emission spectra of thermoluminescence and thermal desorption spectra of adsorbed oxygen have been analyzed. A model implying that the observed processes are due to the excitation of F+ centers is suggested. © 1985 Akadémiai Kiadó.