What is the reason for using two lithium fluoride chips (thin and thick) in the thermoluminescent dosimeter?

The use of two lithium fluoride chips, one thin and one thick, in a thermoluminescent dosimeter (TLD) is significant for accurately measuring the radiation dose received by different tissues in the body. The thin chip is designed to measure the dose to the skin, reflecting the relatively high energy levels that can penetrate just beneath the surface. In contrast, the thick chip measures the deeper tissue or body dose, capturing the radiation exposure that affects a larger volume of tissue.

This dual measurement is essential because different types of biological tissue react differently to radiation exposure. For instance, skin may sustain more immediate damage from high-energy radiation compared to deeper tissues that may accumulate dose differently due to varying energy absorption characteristics. By comparing the readings from both chips, one can obtain a more comprehensive understanding of the radiation exposure that will contribute to potential biological effects and health risks, thereby enabling effective radiation monitoring and safety assessment.