In situ luminescence as monitor of radiation damage under swift heavy ion irradiation

In this paper, we discuss the results of recent ionoluminescence experiments concerning the study of radiation dose effects in α-Al2O3, α-Al2O3:Cr and LiF crystals under the irradiation with different swift heavy ions in a wide range of nuclear and electronic stopping powers. To monitor the lattice disorder in alumina and lithium fluoride, the luminescence of F-type centres have been used. It was shown that the degradation stage of the F+ centre luminescence signal under 710 MeV Bi ion irradiation begins at a very low damage level and cannot be induced by defects produced by elastic collisions. The observed difference in the evolution of F3+-centre luminescence in LiF by swift heavy ions and conventional radiation is ascribed to the high local concentration of defects in the ion-track region. In experiments with ruby, we explored a well-known piezospectroscopic method for in situ monitoring of the build up and accumulation of mechanical stress under the irradiation with high-energy heavy ion. The obtained data strongly imply that the lattice disorder induced by collective electronic excitations plays a dominant role in generation of mechanical stress in the studied fluence range.