Thermoluminescence investigations on tobacco dust as an emergency dosimeter

Abstract

Silicates extracted from tobacco dust in cigarettes were investigated for their suitability as an emergency dosimeter in accidental situation using thermoluminescence technique. A typical glow curve (at a heating rate of 2 °C s−1) of irradiated dust silicates in the transmission window between 300 and 500 nm has two prominent peaks at about 83 °C and 137 °C and a weak one at about 181 °C which were all distinguishable from the natural thermoluminescence. The TL spectrum of highly irradiated dust samples showed the existence of three dominant emissions at 1.66 eV (745 nm), 2.2 eV (560 nm) and 2.81 eV (440 nm), which are similar to those reported for feldspar. Repeated irradiation and TL measurement did not affect the sensitivity of the 137 °C peak, if the glow curve is terminated at 300 °C. A linear dose response of the TL signal was observed for doses between 0.1 and 10 Gy. A preheat temperature of 110 °C was found to be optimal for the emptying of the low temperature peak which is not stable. The TL signal is not stable but fades with time since irradiation. Furthermore it can be bleached by daylight but the dust seemed to be sufficiently light shielded in intact cigarettes. Based on the experimental dosimetric properties, a measurement protocol for the detection of absorbed radiation dose was developed. The result of a dose recovery test showed a reasonable agreement between fading corrected dose and given dose.