Radiological or nuclear emergency OSL dosimetry using commonplace salt

Abstract

During recovery phases following a nuclear or radiological incident, it is crucial to assess the radiation exposure of both the general public and responders. This assessment is vital for directing protective actions and for conducting subsequent analyses of the incident's impact. Several methods have been employed at different timescales after an incident, including assessments based on measurements of materials present at the time of the incident. Common salt has previously been shown to have potential for retrospective dosimetry in the μGy-mGy dose range using portable OSL instruments. This study aims to explore the effects of sample storage under light and dark conditions on OSL signals. The OSL signals indicate a brief decrease in luminescence during the initial days after irradiation, followed by a gradual rise with extended storage. The period from 8 days to 64 days is characterized by relatively stable results, which encompass a significant portion of the timeframe relevant for dose estimation during both the early and later phases of responding to radiological emergencies. Light exposure (simulated daylight) results in an extremely rapid loss of OSL signals. Results are discussed with reference to TL measurements of associated trapping systems which provide insight into potential zeroing mechanisms and the observed fading behaviour. The results are sufficiently favourable to conclude that these characteristics, together with the widespread availability and low cost of household salt, support its use for prompt emergency assessment and as a retrospective dosimeter, below 100 μGy.