A new high sensitivity thermoluminescent phosphor with low residual signal and good stability to heat treatment: LiF:Mg,Cu,Na,Si

The preliminary investigations are reported on the characteristics of a new, high-sensitivity thermoluminescence phosphor material (LiF:Mg,Cu,Na,Si) prepared in this laboratory. The main dosimetric peak of this phosphor occurs at 197 deg. C at a heating rate of 1 deg. C s-1. The glow curve shape shows minimal differences and sensitivity remains stable when annealed in the range from 250 to 280 deg. C for 10 min. Its TL sensitivity to gamma radiation is about 30 times higher than that of TLD-100 with a residual signal 0.2% following a 260 deg. C readout at a heating rate of 15 deg. C s-1. This negligible residual signal renders LiF;Mg,Cu,Na,Si usable in unannealed form. Its TL response at both 260 deg. C and 280 deg. C are reproducible within a coefficient of variation of 2% over ten re-use cycles without systematic decrease. It retains the main advantages of LiF:Mg,Cu,P phosphor, and has a lower residual signal and a better stability to heat treatment. (author)