Physical and dosimetric properties of NaCl pellets made in-house for the use in prospective optically stimulated luminescence dosimetry applications

Abstract

In this paper, NaCl pellets are produced in-house from ordinary household salt using simple and accessible methods, for the purpose of suggesting a cost-effective and available tool for various optically stimulated luminescence dosimetry applications. First, the pellets are investigated in terms of optimal configuration by varying combinations of grain sizes and compression forces. Then, the pellets with the optimal configuration are further investigated in terms of dosimetric properties such as signal-dose response, dose estimation, reproducibility, radiation induced sensitisation, detection limits and signal stability over time. The radiation induced OSL signals are read at room temperature and dose estimations are performed using one calibration dose.The optimal pellet configuration, for the three salts investigated, was achieved with 100–400 μm sized salt grains and a compression force of 3.0 ± 0.5 tons. With the proposed NaCl pellets, readout and calibration procedure, it is possible to achieve a linear dose response in the dose range from 0 to 300 mGy. When using a calibration dose for signal normalisation the reproducibility of the radiation induced OSL signal is within 1.5% and when using the most optimal calibration dose for each salt the estimated dose is within 3% of the given dose. The detection limits for the salts investigated are, in terms of minimum detectable dose, between 5 and 21 μGy. Considering these findings and the overall cost of manufacturing NaCl pellets i.e. the worldwide availability, the proposed method opens for radiation protection measurements that have so far been too expensive or impossible.