SENSITIVITY OF A MIXED FIELD DOSIMETRY ALGORITHM TO UNCERTAINTIES IN THERMOLUMINESCENT ELEMENT READINGS

An error analysis of the effects of the algorithms used to resolve the deep and shallow dose components for mixed fields from multi-element thermoluminescent (TLD) badge systems was undertaken for a commonly us ed system. Errors were introduced independently into each of the four element readings for a badge, and the effects on the calculated dose e quivalents were observed, A normal random number generator was then ut ilized to introduce simultaneous variations in the element readings fo r different uncertainties, The Department of Energy Laboratory Accredi tation Program radiation fields were investigated. Problems arising fr om the discontinuous nature of the algorithm were encountered for a nu mber of radiation sources for which the algorithm misidentified the ra diation field. Mixed fields of low energy photons and betas were found to present particular difficulties for the algorithm, The study demon strates the importance of small fluctuations in the TLD element's resp onse in a multi-element approach.