LiF-TLD in the microgray dose range via computerised glow curve deconvolution and background smoothing

A computerized glow curve deconvolution technique (CGCD) and its application to the ultralow dose thermoluminescence (TL) glow curve of LiF:Mg,Ti (TLD-100) are described. The benefits in precision and minimum measurable dose (MMD) applied to TLD-100 are considerable. The CGCD analysis interpolatively estimates the background signal under peaks 4 and 5 which greatly reduces the errors introduced by inaccurate background subtraction due to second readout as well as eliminating the need for second readout. In addition, the error introduced via inaccurate separation of peak 3 is reduced and post-irradiation annealing is rendered unnecessary. An additional important feature of the CGCD method is the ability to reject/correct outliers in the glow curve. Assuming a MMD criterion of + - 20% (1 SD) precision yields a MMD of 1.9 μGy and 27 μGy for CGCD and routine analysis respectively, i.e. an improvement in MMD of a factor 14.2. (author)