INVESTIGATION OF RADIATION-INDUCED DEFECTS IN NABR-SR2+

An EPR/ENDOR study of two radiation-induced defects in NaBr doped with Sr2+ is presented. X-irradiation at room temperature produces a large amount of F centres compared to undoped NaBr and an impurity-related hole centre of Br-2(-)-type. An ENDOR investigation of the F centre yi elded the superhyperfine interaction constants for the first two shell s of neighbours. The Br-2(-)-type hole centre has properties very simi lar to the H-DD([100]) centre in KCl:Sr2+. In contrast to the centres in KCl, which decay thermally at 255 K, the H-DD centre in NaBr is sta ble at room temperature.