Irradiation effects in LiF : Eu+3

Effects of X, beta and VUV irradiations on LiF:Eu3+ were studied and compar ed to those induced in nominally purl LiF. In the pure crystals thermolumin escence (TL) could be excited by X- or beta-rays; ill LiF:Eu3+ the TL could also be excited by VUV radiation with excitation maxima at 190 nm and near 125 nm. The 190 nm maximum coincided with a weak absorption band, recorded in the irradiated crystals. A strong optically stimulated thermoluminescen ce (OSTL) also appeared in pure crystals, which had previously been X- or b eta-irradiated at RT and then illuminated at LNT with 190 nm. The fact that the OSTL and the TL showed the same excitation maxima in both crystals, in dicates that they are due to the same trapping states. Different emission b ands were, however, recorded by the same excitation in LiF:Eu3+ and pure Li F samples. Results have shown that the radiation sensitivity of the Eu3+ do ped samples is by an order of magnitude higher than that of pure LIF crysta ls but by about an order of magnitude lower than that of LiF:Mg,Ti (TLD100) . (C) 2000 Elsevier Science B.V. All rights reserved.