In-situ investigation of point defects kinetics in LiF using ion luminescence technique

The present work reports the in-situ ion beam induced luminescence measurements using 2 MeV proton excitation of LiF single crystal with the aim of obtaining a further insight on F-type centers kinetics and its correlation with the self-trapped exciton (STE). It is found that the STE luminescence intensity decreases from the beginning of irradiation. While the dose-dependent evolution of F₃ ⁺ and F₂ centers reveals three kinetic stages: (i) linear increase from the beginning of irradiation up to 10.1 MGy, followed by (ii) monotonic decrease to 18.1 MGy, and (iii) steady state from 18.1 to 26.2 MGy where the luminescence intensity remains constant. The STE luminescence completely extinguished at high dose; 18.1 MGy in our case. Whereas, the F₃ ⁺ and F₂ luminescence persist and remain constant above 18.1 MGy. The latter behavior revealed in the present study can be useful for LiF application in radiation dosimetry and an imaging detector.