Glow Curve Analysis of Long-term Stability of LiF:Mg,Cu,P as Compared to LiF:Mg,Ti

Over a six month period, the long-term stability of LiF:Mg,Cu,P (GR-200A, Beijing China) was compared with LiF:Mg,Ti (GR-100, Beijing China). This is of particular interest in applications where there can be considerable variations in the time intervals between TLD preparation, irradiation and readout, such as environmental, accident personal and mailed dosimetry. For each TLD material, slow and fast cool-down anneals, characteristic of those used in the above-mentioned applications, were employed to study the effect of annealing procedure on long term stability. An analytical approximation based on the Randal-Wilkins model employing first order kinetics was used to fit individual peaks. Glow curve features unique for each TLD material and annealing condition were quantified and compared. From computerised glow curve analysis, annealing at 220 deg. C, instead of the pre-set temperature of 240 deg. C, caused an increase in the contribution from peak 3 in LiF:Mg,Cu,P, causing the material to be more susceptible to fading and peak area interchanges. (author)