Photoluminescence of radiation-induced color centers in lithium fluoride thin films for advanced diagnostics of proton beams

Systematic irradiation of thermally evaporated 0.8 mu m thick polycrystalline lithium fluoride films on glass was performed by proton beams of 3 and 7MeV energies, produced by a linear accelerator, in a fluence range from 10(11) to 10(15) protons/cm(2). The visible photoluminescence spectra of radiation-induced F-2 and F-3(+) laser active color centers, which possess almost overlapping absorption bands at about 450 nm, were measured under laser pumping at 458 nm. On the basis of simulations of the linear energy transfer with proton penetration depth in LiF, it was possible to obtain the behavior of the measured integrated photoluminescence intensity of proton irradiated LiF films as a function of the deposited dose. The photoluminescence signal is linearly dependent on the deposited dose in the interval from 10(3) to about 10(6) Gy, independently from the used proton energies. This behavior is very encouraging for the development of advanced solid state radiation detectors based on optically transparent LiF thin films for proton beam diagnostics and two-dimensional dose mapping. (C) 2015 AIP Publishing LLC.