Beta Dosimetry Using Thin Layer Alpha-Al2O3:C TL Detectors

The possibility of using thin-layer α-Al2O3:C thermoluminescence detectors (TLD) for the measurement of the annual beta dose from natural materials, considered for retrospective luminescence dosimetry, archaeometry and authenticity testing was checked. The annual beta doses from various materials including some porcelains, bricks and soils were determined by storing the detectors underneath the samples in a shielded environment for a period of time. Beta doses from two feldspar standards NBS 70a and NBS 99a (K and Na feldspars) and some environmental samples including ceramics, porcelain and soil with well known U, Th and K contents, were measured using the same aluminium oxide detectors. The annual doses measured by thin-layer detectors agreed well within 5% with the values calculated using the radionuclide concentrations. The results of the experiments have shown that thin-layer aluminium oxide dosemeters can be used successfully for the measurement of annual beta doses from natural materials collected for retrospective dosimetry and also for dating purposes. Due to the extremely high sensitivity of the detectors, the dose rates can be measured after a few weeks of exposure. The detectors were further shown to be useful for monitoring the dose on the surface due to contamination, their penetration through bricks collected from nuclear accident sites and for determining the beta dose due to radioactive nuclei in the glaze of some porcelain products. (author)