A time-resolved analysis of differential thermoluminescent signal fading and trap dynamics.

Thermoluminescent materials are explored as passive devices for reconstructing radiation exposure events. The work is motivated by the need for reliable exposure timestamping in applications from nuclear safeguards to accident investigation and retrospective dosimetry. In these contexts, determining the time since exposure provides valuable information for reconstructing material movements, clarifying accident dynamics, and supporting decision-making. The research focuses on LiF:Mg,Cu,P, exploiting its intrinsic differential fading behaviour. The proposed methodology relies on a dual-marker approach. The first component is based on fading analysis, in which low-temperature peaks are compared with the stable dosimetric one. The achievable temporal resolution and the contribution of background radiation to signal buildup are experimentally evaluated. The study also demonstrates that temperature excursions significantly accelerate signal fading, highlighting the importance of thermal control in practical applications. The second component is based on trap-dynamics analysis, tracking the temporal evolution of activation energies derived from glow-curve deconvolution. The results reveal a time-dependent reorganisation of shallow traps consistent with thermally activated tunnelling recombination. The investigation also evaluates BeO as an alternative material, which proved less suitable for the explored timescale but warrants further investigation for longer-term exposure timestamping