Evaluating SMD resistors in electronic devices as accident dosimeters using red thermoluminescence

Abstract

Traditional protocols utilizing optically stimulated luminescence (OSL) and thermoluminescence (TL) of surface-mounted devices (SMDs) for retrospective dosimetry have demonstrated promising results, but limitations in sensitivity, especially for a limited number of SMD components, and small sample sizes, have prompted the exploration of alternative methods. The red thermoluminescence (RTL) protocol has emerged as a promising alternative, taking advantage of the strong TL emission of SMD components in the near-infrared spectral range.

The present study investigates the dosimetric performance of red thermoluminescence (TL) emission from surface-mounted devices (SMDs) and its potential for use in accident dosimetry. Key characteristics, such as intrinsic zero-dose signal, signal reproducibility, dose-response relationship, signal stability, and a dose recovery test, were systematically analysed. An irradiation experiment was conducted in which SMDs were exposed to 6 MV X-rays using LINAC, and subsequent dose reconstruction was carried out employing the RTL protocol. The experiments demonstrated that a new RTL protocol yields promising signal intensities, and successful dose reconstruction was achieved even after delayed readout, with fading corrections applied. Dose estimates obtained from single SMD resistors, both reference components and those extracted from a smartwatch, showed good agreement with reference dosimeters, with overestimations between 5 % and 24 %. These findings confirm that the RTL method includes sufficient sensitivity and the ability to analyse very limited sample quantities, particularly in scenarios where signal sensitivity is critical.