Development of a Physical Phantom for Occupational Eye Lens Dosimetry in a Non-homogeneous Radiation Field.

Abstract

Following the reduction in the occupational eye lens dose limit by the International Commission on Radiological Protection (ICRP), a physical phantom was developed to enable lens dose monitoring in complex radiation environments. The design is based on a validated eye model used to derive lens dose conversion coefficients. After evaluating various materials using Monte Carlo simulations, polymethyl methacrylate (PMMA) was selected for its ease of manufacturing and decontamination. The phantom's dose conversion coefficients were calculated for a range of photon energies and irradiation angles. Lens doses were measured using thermoluminescent dosimeter (TLD) chips embedded in the phantom and exposed to a 137 Cs reference field. Measurements were compared with simulation results, demonstrating good agreement. This newly developed PMMA phantom offers a practical solution for evaluating lens dose in non-uniform radiation fields such as those found in nuclear power plants.