Prototype Development of a Thermoluminescence Dosimeter Based on Monte Carlo Simulation Methods

The European Directive 96/29/EURATOM and adapted national regulations on radiation protection are claiming new limits of radiation exposure and the introduction of new measuring quantities. Dosimeters for area monitoring of penetrating X-ray and gamma radiation have to measure the ICRU operational quantity ambient dose equivalent, H*(10). In this paper, the development stages of a passive H*(10) area dosimeter based on thermoluminescence detectors (TLDs) are described. The design of the dosimeter and the optimization of the combined energy and directional response are almost completely performed by MCNP Monte Carlo computer simulations. At the end of the first prototype development stage, two prototypes containing three TLD cards were manufactured according to the simulation results. The optimization method and dosemeter properties could be confirmed by the concluding verification experiment. The prototypes of the second development phase were especially optimized for measuring independent of the direction of incident photon radiation fields. Additionally, an aluminium cap was introduced for environmental protective purposes. The third-stage prototypes currently under testing were planned as the final stage of the presented dosimeter development process. Their design was optimized on meeting specific requirements of passive area monitoring devices in routine applications.