AGING OF THE SELF-TRAPPED EXCITON LUMINESCENCE UNDER SWIFT HEAVY-ION IRRADIATION

We have studied the self-trapped exciton, STE, luminescence at low tem peratures, in NaCl and KBr, submitted to the very dense electronic exc itations induced by swift heavy ions. As soon as the sample is damaged , the luminescence spectra are drastically modified, We have observed a decrease of the standard sigma and pi luminescence and the emergence of new luminescence bands, only if the irradiation temperature is suf ficiently high, It is the luminescence ageing. This article presents o ur first results on the kinetics of the luminescence ageing under swif t heavy ion irradiation. We strongly presume that STE-defect interacti ons occur and modify the STE radiative recombination. Consequently, th e STE luminescence ageing kinetics can be a good probe of the radial e xtension of the ion energy deposition, In the light of these results, for our experimental conditions, the radial extension of the STE aroun d the ion path is estimated to be at least 40 nm.