Laser assisted thermoluminescence dosimetry using temperature controlled linear heating

We have developed a non-contact laser-fiberoptic system for thermoluminescence dosimetry (TLD) measurements. The system is based on: (i) linear heating of a TLD sample by a CO₂ laser beam; (ii) measuring the sample's temperature, using infrared thermometry and (iii) using a feedback loop, for controlling the heating rate. The infrared thermometry was carried out, using infrared transmitting AgClBr fibers. The system made it possible to obtain linear heating at slow rates (e.g. 5 °C/s), or fast rates (up to 60 °C/s), or even to obtain non-linear heating. Measurements on LiF TLD samples revealed excellent linearity between the doses, to which the samples had been exposed, and the amplitudes of the measured glow curve peaks, over a wide range of doses. Our results were highly reproducible, which clearly demonstrated the potential of laser heated thermoluminescence for accurate dosimetry.