Radiation damage in single crystal CsI(T1) and polycrystal CsI was assessed by measuring the changes in radioluminescent intensity caused by successive neutron and gamma ray pulses from a TRIGA nuclear reactor. The radioluminescent intensity from the single crystal decreases within nine pulses by 30% in the near infrared range (0.7-4.5 Ã‚ÂµM) and by 25% in the visible range (0.2-1 pm) before staying constant. For the polycrystal CsI, the emission in the visible range decreases by 60% within 6 pulses and then remains constant, whereas no measurable emission is observed in the infrared. Finally, a heating and cooling cycle is shown to repair the damage for both crystals.
"Radiation damage in single crystal CsI(T1) and polycrystal CsI", Proc. SPIE 1438, Laser-Induced Damage in Optical Materials 1989, 14381I (1 November 1990); doi: 10.1117/12.2294463; https://doi.org/10.1117/12.2294463