Lithium fluoride represents the most frequently used base material for thermoluminescent detectors. The glow curve of these detectors is composed of a series of peaks which intensities strongly depend on the given dose, the type and energy of the impinging radiation, the concentration of dopants in the crystal and the lithium isotopic concentration. In this work, 6LiF:Mg,Ti, 7LiF:Mg,Ti, 6LiF:Mg,Cu,P and 7LiF:Mg,Cu,P detectors were exposed to calibrated hydrogen, helium and carbon ion beams in order to investigate the change of the structure of the different peaks composing the glow curves of these materials and their relative luminescence efficiency. In order to resolve the different peak contributions, computer assisted deconvolution of the glow curve was performed and the used sets of parameters (activation energy E and temperature at peak maximum Tmax) are presented. In the case of LiF:Mg,Ti detectors, the low temperature peaks and the main peak are characterized by a general efficiency decrease with the increase of the LET of the incident particle. No remarkable differences were found between detectors enriched with 6Li or 7Li. On the other hand, differences in the structure of the high temperature peaks between the two lithium isotopic compositions were found and discussed. Regarding LiF:Mg,Cu,P detectors, each peak shows a general monotonously decreasing relative efficiency with the increase of LET. In this case, a similar LET dependence was found between 6Li and 7Li based detectors. Furthermore, unusual efficiencies greater than 1 for the low temperature peaks of LiF: Mg,Cu,P exposed to low LET particle were observed.
|Number of pages
|Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
|Published - 12 Jul 2017