CHARACTERIZATION AND PERFORMANCE TESTS OF A NEW OSL/TL PERSONAL DOSEMETER FOR INDIVIDUAL MONITORING

Comparison of OSL and TL dosimetry systems against IEC and ICRP standards

Personal and environmental radiation monitoring services are widely used through luminescent techniques. In this paper, we practiced performance testing on thermoluminescent and optically stimulated luminescent dosimeters by assessing their homogeneity, linearity, energy, and angular dependence tests. The IEC and ICRP requirements were used to compare the performance response of dosimeters. Based on the experimental results, we realized that both detectors comply with the international criteria. The homogeneity percentage was 8.9% and 13.7% for TL and OSL detectors, respectively. The percentage deviation of the linearity test does not exceed 10% for both dosimeters except for the TL dosimeters at low irradiation dose. For the angular dependence, deviations were less than 2% for TLDs and 5% for OSLDs. These detectors display mean values of the relative energy response of -15.29% and -6.51% for OSL and TL detectors. Generally, TL materials manifested low sensitivity to radiation dose levels. On the other hand, the OSLDs demonstrated a more pronounced under-response to energy beam qualities than TLDs. Regarding COV tests, TL and OSL dosimeters have passed the c2 test.

DEVELOPMENT OF OPTICALLY STIMULATED LUMINESCENCE BADGE READER SYSTEM FOR INDIVIDUAL MONITORING OF RADIATION WORKERS

A new Optically Stimulated Luminescence Badge Reader (OSBARE-1) system has been designed and developed for application in the individual monitoring dosimetry. This badge reader system utilizes the 470-nm light of a blue LED for CW-OSL readout with the help of PMT photon counting module. The developed reader system can process four element 24 OSLD cards within 25 min. These four-element OSLD card consists of the Teflon embedded indigenously developed dosimetric grade α-Al2O3:C phosphor. The minimum measurable dose (MMD) was found to be ~26 μGy for these OSLD cards with reproducibility of ~1.12%. The various operational parameters such as variation in the dark counts, OSL scattering background counts and reproducibility have been studied in detailed for this reader system. The dosimetric studies performed on this developed reader system found to have a great potential for the OSLD-based large-scale personnel monitoring program for the radiation workers.