Radiation sensitivity of memory chip module of an ID card

The utility of ID card chip modules to function as a radiation dosimeter is investigated. Specifically the thermoluminescence (TL) and optically stimulated luminescence (OSL) of a sampling of chip modules are measured over the range of 0.4–12 Gy. Both infrared (830 nm) from a laser diode and blue light (470 nm) from LEDs were used to perform the OSL measurements. The TL measurements showed a linear dose–response relationship, but the TL suffered from a large zero-dose signal in the unirradiated samples and dose regeneration with time after heating the chip modules. The OSL measurements also showed a linear dose–response, but did not exhibit a zero-dose signal or regeneration. Performing the infrared OSL measurements at a temperature of 140∘C may improve the dose sensitivity to 0.15 Gy, but the dose–response is supralinear in the dose range investigated. Curve fitting of infrared and blue stimulated luminescence curves showed that both exhibit a fast and a slow component. Thermal stability studies indicates the presence of a component that decays in the first hour of irradiation, and a component that is stable at least during the period of investigation (up to 10 h). This stable component is more appropriate for dosimetry purposes.