On the possibility of using commercial software packages for thermoluminescence glow curve deconvolution analysis.

This paper explores the possibility of using commercial software for thermoluminescence glow curve deconvolution (GCD) analysis. The program PEAKFIT has been used to perform GCD analysis of complex glow curves of quartz and dosimetric materials. First-order TL peaks were represented successfully using the Weibull distribution function. Second-order and general-order TL peaks were represented accurately by using the Logistic asymmetric functions with varying symmetry parameters. Analytical expressions were derived for determining the energy E from the parameters of the Logistic asymmetric functions. The accuracy of these analytical expressions for E was tested for a wide variety of kinetic parameters and was found to be comparable to the commonly used expressions in the TL literature. The effectiveness of fit of the analytical functions used here was tested using the figure of merit (FOM) and was found to be comparable to the accuracy of recently published GCD expressions for first- and general-order kinetics.

Detailed kinetic study of the thermoluminescence glow curve of synthetic quartz.

A detailed kinetic analysis has been performed of the thermoluminescence (TL) glow curve of high purity synthetic quartz. The kinetic parameters of the glow peak at 110 degrees C were evaluated for doses ranging from 0.1 Gy to 100 Gy using glow curve deconvolution (GCD), initial rise, variable heating ratc and phosphorescence decay methods. All the methods gave results that agree within the experimental errors.

Search for common characteristics in the glow curves of quartz of various origins.

The thermoluminescence (TL) glow curves of quartz of various origins were measured under two different conditions, (1) unannealed samples and (2) samples annealed at 500 degrees C and 900 degrees C. The different glow curves obtained were analysed using first order kinetics and glow curve deconvolution (GCD) analysis. The comparison of the glow curves obtained was mainly concentrated in studying the sensitivities of the glow peaks as a function of the annealing temperature, and in obtaining the kinetic parameters of the glow peak at '110 degrees C'. Furthermore, in four samples the detailed comparison was extended to the trapping parameters of all existing glow peaks. It was found that despite their different origin and the different shapes of the glow curves, there are several basic characteristics that are common to all samples studied.

Fit of second order thermoluminescence glow peaks using the logistic distribution function.

A new thermoluminescence glow curve deconvolution (GCD) function is introduced which accurately describes second order thermoluminescence (TL) curves. The logistic asymmetric (LA) statistical probability function is used with the function variables being the maximum peak intensity (Im), the temperature of the maximum peak intensity (Tm) and the LA width parameter a2. An analytical expression is derived from which the activation energy E can be calculated as a function of Tm and the LA width parameter a2 with an accuracy of 2% or better. The accuracy of the fit was tested for E values ranging from 0.7 to 2.5 eV, for s values between 10(5) and 10(25) s(-1), and for trap occupation numbers no/N between 1 and 10(-6). The goodness of fit of the logistic asymmetric function is described by the Figure of Merit (FOM) which is found to be of the order of 10(-2). Preliminary results show that the GCD described here can easily be extended to the description of general order TL glow curves by varying the asymmetry parameter of the logistic asymmetric function. It is concluded that the TL kinetic analysis of first, second and general order TL glow curves can be performed with high accuracy and speed by using commercially available statistical packages that incorporate the Weibull and logistic asymmetric functions.

Fit of first order thermoluminescence glow peaks using the Weibull distribution function.

A new thermoluminescence glow curve deconvolution (GCD) function is introduced which accurately describes first order thermoluminescence (TL) curves. The new GCD function is found to be accurate for first order TL peaks with a wide variety of the values of the TL kinetic parameters E and s. The 3-parameter Weibull probability function is used with the function variables being the maximum peak intensity (Im), the temperature of the maximum peak intensity (Tm) and the Weibull width parameter b. An analytical expression is derived from which the activation energy E can be calculated as a function of Tm and the Weibull width parameter b. The accuracy of the Weibull fit was tested using the ten reference glow curves of the GLOCANIN intercomparison program and the Weibull distribution was found to be highly effective in describing both single and complex TL glow curves. The goodness of fit of the Weibull function is described by the Figure of Merit (FOM) which is found to be of comparable accuracy to the best FOM values of the GLOCANIN program. The FOM values are also comparable to the FOM values obtained using the recently published GCD functions of Kitis et al. It is found that the TL kinetic analysis of complex first-order TL glow curves can be performed with high accuracy and speed by using commercially available software packages.