An optimized computational method for determining the beta dose distribution using a multiple-element thermoluminescent dosimeter system.
This paper describes an optimization method for determining the beta dose distribution in tissue, and it describes the associated testing and verification. The method uses electron transport theory and optimization techniques to analyze the responses of a three-element thermoluminescent dosimeter (TLD) system. Specifically, the method determines the effective beta energy distribution incident on the dosimeter system, and thus the system performs as a beta spectrometer. Electron transport theory provides the mathematical model for performing the optimization calculation. In this calculation, parameters are determined that produce calculated doses for each of the chip/absorber components in the three-element TLD system. The resulting optimized parameters describe an effective incident beta distribution. This method can be used to determine the beta dose specifically at 7 mg X cm-2 or at any depth of interest. The doses at 7 mg X cm-2 in tissue determined by this method are compared to those experimentally determined using an extrapolation chamber. For a great variety of pure beta sources having different incident beta energy distributions, good agreement is found. The results are also compared to those produced by a commonly used empirical algorithm. Although the optimization method produces somewhat better results, the advantage of the optimization method is that its performance is not sensitive to the specific method of calibration.
D000465:Algorithms; D001610:Beta Particles; D005459:Fluorides / Q000528:radiation effects; D006801:Humans; D008094:Lithium / Q000528:radiation effects; D018020:Lithium Compounds; D012867:Skin / Q000528:radiation effects; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation / Q000379:methods*
D018020:Lithium Compounds; C027651:lithium fluoride; D008094:Lithium; D005459:Fluorides