Investigation of emission spectra, dose response and stability of luminescence from NaCl

The thermoluminescence (TL) from common salt (NaCl) is investigated to determine its suitability as an opportunistic retrospective dosimeter. In this study the TL is analysed from a wide range of domestic salts, sourced from Australasia, Europe, Asia and America. The emission spectra for pre-existing or "Natural" TL (NTL) and laboratory-irradiated "Artificial" TL (ATL) were analysed using a Fourier Transform spectrometer, giving luminescence intensity as a function of temperature and photon energy. Fading behaviour in the candidate TL emission peaks, observed at 200-260 °C under the measurement conditions used, was investigated at various storage temperatures and storage intervals between irradiation and read-out. This included TL emission spectral measurements at storage intervals ranging from minutes to months. Nearly all samples showed strong ATL emission at 590 nm, with much weaker emission from the commonly measured UV-blue region. NTL was very small or undetected for most samples. The storage tests showed that the TL in the 260 °C region is relatively stable and we conclude that TL from NaCl possesses suitable dose sensitivity and stability for use as an opportunistic retrospective dosimeter. Crown Copyright © 2012 Published by Elsevier Ltd. All rights reserved