HOT PARTICLE DOSIMETRY USING LASER-HEATED THERMOLUMINESCENT DOSIMETRIC FOILS COMPARED TO EGS4-PRESTA CALCULATIONS

The dose distribution originating from a small radioactive particulate , a 'hot particle', has been evaluated using laser heated thermolumine scent dosimetric foils (TLD) scanned by a CO2 infrared laser beam. Exp erimental results have been compared with calculations using the EGS4- PRESTA transport code. Calculations show clearly the contribution of b eta and gamma radiations to the radial and depth dose rate. Below a ma ss thickness of about 40 mg.cm(-2), the beta dose is preponderant and above that the contribution of gamma radiation is significant. Neverth eless, there is a great discrepancy between calculations and TLD measu rements which are around a factor of 2.2 for mass depths lower than 40 mg.cm(-2).