Simultaneous in situ luminescence and optical absorption studies were made of CsI and CsI–Tl crystals which were exposed to very dense electronic excitations that were induced by 86Kr ions (8.63MeV/amu). Irradiation at 15K led to the formation of a prominent F absorption band. Other features of the broad absorption between exciton and F bands were attributed to an anion vacancy, α-center (240nm), self-trapped hole, Vk center (410nm) and interstitials, and H centers (560nm). Low (1017/cm3) dopant levels of Tl caused F-center formation to proceed more rapidly than in the pure crystal. It was not possible to create F centers in heavily-doped CsI–Tl. Point defects that were created by heavy ions were revealed by luminescence aging.

F Center Production in CsI and CsI–Tl Crystals under Kr Ion Irradiation at 15K. A.I.Popov, E.Balanzat: Nuclear Instruments and Methods in Physics Research B, 2000, 166-167, 545-9