ESTIMATION OF PERSONAL DOSE EQUIVALENT HP(0.07) USING CASO4:DY TEFLON DISC-BASED EXTREMITY DOSEMETER

Abstract

The radiation workers in India use extremity dosemeter in occupational areas where there is likelihood of receiving significant dose to extremities of the body. Algorithm used for the estimation of whole body dose and extremity dose of wrist are same and is based on slab phantom calibration. However, internationally, different phantoms are recommended for calibration of dosemeter used for extremity and whole body. The recommended quantity for estimation of dose to extremity is the personal dose equivalent Hp(0.07) at 0.07 mm depth. In light of this, an algorithm was developed for estimation of wrist dose in terms of Hp(0.07) based on calibration performed on ISO recommended pillar phantom. Performance of the dosemeter for the estimation of Hp(0.07) with new algorithm was carried out at different angular exposures of photon beams and mixed field of photon and beta. Comparison of results obtained for two types of ISO phantoms (slab and pillar) is also performed for photon beams to highlight the uncertainty caused due to the use of the slab phantom. In case of beta radiation, it was found that the size and shape of the phantom has very little influence in the response of the dosemeter. Performance of the dosemeter using ISO slab and ISO pillar phantoms for beta radiation using the prevalent algorithm was carried out and found to be within the uncertainty limits laid down by ISO except at angle 60°.

A multi-stage machine learning algorithm for estimating personal dose equivalent using thermoluminescent dosimeter

“…Response of TLD badge in terms of operational quantities has been reported in a few studies [9,10,12,13,26]. These experimental TL response datasets were compiled, consisting of approximately 700 sets of TL readouts.…”

“…The energy and angular dependence of the response presents a challenge for the accurate estimation of occupational doses. The dose estimation algorithms presently used, either consider the angle-averaged response or the response at normal incidence to fit the response function [9][10][11][12][13]. When dealing with lower and intermediate photon energy, both the angular and energy response changes rapidly.…”