Effects of the thermal annealing on the traps and recombination centres in LiF:Mg,Cu,P thermoluminescence dosimeter

摘要

Two emission bands A and B at 3.09 and 3.47 eV, respectively, and five thermal peaks were recorded in the 240℃ annealed LiF:Mg,Cu,P samples. Based on the study on the thermoluminescence spectra and glow curves in the samples annealed between 240 and 700℃ the following observations were made. The recombination centre R_A decays above 240℃, but can be partially recovered during cooling, if the sample has not been heated to 360 ℃ or above. The recombination centre R_B converts to R'_B when the sample is heated to above 240℃, leading to the emission band B shifts to higher energy and this process is irreversible when the sample is cooled down. The conversion of trap 4 to trap 5 occurs when the annealing temperature T_A is 270-330℃. The converse process takes place when T_A is 330-700℃.