A dosemeter for the public based on NaCl pellets for use in radiological or nuclear emergencies

Sodium chloride (NaCl) has been proposed as a retrospective and prospective dosemeter for optically stimulated luminescence (OSL) dosimetry. The potential for NaCl pellets for individualisedin situdose assessment during a radiological or nuclear emergency was enhanced by their suitability with a portable OSL reader. The current paper studies the possibility of developing a public dosimetric badge, based on NaCl pellets and commonly available low-cost materials. Copper, aluminium and polylactic acid were tested for reducing the overresponse to low x-ray energies, and the results indicated that copper is the best candidate-material for filtering purposes. Furthermore, the ratio between filtered and unfiltered samples may potentially be used to determine the mean energy of the exposure field in some circumstances. In addition, the NaCl pellets exhibit constant response for air kerma rates between 0.006 and 1.9 Gy min^-1. The fading of the pellets does not present any energy dependence. Air kerma reconstruction with three stimulation modes was investigated, and the reconstructed air kerma deviated from the nominal value between 0.8 and 7.9%, which were within measurement uncertainties. The discrepancy between Monte Carlo simulations of the exposed pellets and the experimental data is possibly due to the intrinsic luminescent efficiency of the salt, which in the current study is assumed constant for the entire energy regime. Alanine, exposed together with the NaCl pellets, was studied for the intercomparison and air kerma rate experiments, and showed accurate air kerma reconstruction, with deviation from the actual doses within ∼1σ, and no significant variation with the air kerma rate. Analysis of the alanine dose estimations investigated the conventional peak-to-peak method alongside a fitting method, which did not lead to any improvements in measurement accuracy.