Development and testing of a thermoluminescence dosemeter for mixed neutron-photon-beta radiation fields

A new four-element thermoluminescence (TL) dosemeter and dose evaluation algorithm have been developed and tested to better characterise personnel exposure in mixed neutron-photon-beta radiation fields. The prototype dosemeter is based on a commercially available TL card (with three (LiF)-Li-7 chips and one (LiF)-Li-6 chip) and modified filtration elements. The new algorithm takes advantage of the high temperature peak characteristics of the (LiF)-Li-6 element to quantify the neutron dose component better. The dosemeter was tested in various radiation fields, consisting of mixtures of two radiation types typically used for dosemeter performance testing, as well as mixtures of three radiation types to simulate possible exposure conditions. The new dosemeter gave superior performance, based on the tolerance levels, when using the new algorithm as compared to a conventional algorithm that did not use the high temperature peak methodology. The limitations and further improvements are discussed.