The effect of thermal annealing on defect structure and thermoluminescence in LiF:Mg,Cu,P

We have studied the behavior of the glow peaks in the thermoluminescence of LiF:Mg,Cu,P as a function of pre-irradiation annealing temperature in the range 80 to 170°C, and as a function of cooling rate following the 240°C/10 min anneal used for standardization in dosimetric procedures. The intensities of the major peaks in LiF:Mg,Cu,P (as well as in LiF:Mg,Ti-the current industrial standard) seem to be determined by the dynamics of clustering of (Mg²⁺-Li_vac) dipoles to dimers, trimers and a precipitate phase. The intensities of the thermal interactions, however, seem to be somewhat reduced in LiF:Mg,Cu,P compared to LiF:Mg,Ti. In addition, it seems plausible that phosphorus takes the role of titanium in LiF:Mg,Cu,P in the formation of a trapping center/recombination center spatially correlated complex.