NUMERICAL MODELING OF A NEW METHOD FOR DETERMINATION OF SHALLOW DOSE AND DEEP DOSE IN LOW LET RADIATION-FIELDS

This study introduces a new TLD reading technique to be adopted for lo w LET radiation field dosimetry capable of shallow and deep dose measu rements which utilises simultaneously obtained integrated glow values from two sides of a hot gas-heated TLD slab. Time-dependent temperatur e profiles and the Randall-Wilkins TL model are utilised to simulate T L signal production. Assuming a given form for depth-dose distribution and TL light attenuation in the chip, the pair of integral glow value s are used with the associated system of equations describing glow pro duction to reconstruct the depth-dose distribution, from which shallow dose and deep dose may be estimated. The method is evaluated for a si mulated LiF TLD irradiated in various radiation fields. For a 5% fluct uation in the response of the TLD, errors range from -4.4% to -13.5% f or shallow dose and -2.6% to +16.3% for deep dose.