TSEE characteristics of LiF:M,C,P detectors

LiF based thermoluminescence detectors are most attractive amongst various thermoluminescent dosimetric materials because of their low energy dependence and near tissue equivalence. The ultra sensitive LiF:Mg,Cu,P detectors now are available on commercial scale and widely used for personal dosimetric and environmental monitoring purposes. The Chinese type GR-200 and MCPN LiF:Mg,Cu,P IPN, Krakow TL detectors are similar in their main characteristics. The effective atomic number is 8.2, the emission spectrum maxima is 4000 A, typical sensitivity at 60Co relative to TLD-100 is 15-50, the overresponse at 30 keV/60Co is 1.06 and the fading is negligible, less 5%/year. The useful dose range of this material is 1μ y-10 Gy. The high sensitivity of this material allow to prepare thin sensitive layers by which nearly energy independent beta dose measurement can be performed. LiF:MCP detectors are very delicate regarding their heat treatment. Typically 10 mins at 240 deg. C is the annealing suggested even though annealing up to 270 deg. C may give good reproducibility, too. Up to 12-15 % loss in sensitivity was observed on repeated measurements up to 50 cycles using 10 mins annealing at 240 deg. C. Annealing up to 400 deg. C for 2 hrs resulted the shift of the main dosimetric peak together with a significant decrease of sensitivity. LiF based dosimetric materials besides TL exhibit thermally stimulated exoelectron emission, TSEE, phenomenon, too. The analysis of TL and TSEE glow curve structure may reveal interrelation between peaks therefore the physical process responsible for emissions. The main purpose of present work was to measure and investigate both TL and TSEE responses of LiF:Mg,Cu,P detectors using different heat treatment