TSEE dosimetry system for low-level monitoring

Among detector materials used in TSEE dosimetry different BeO ceramics activated with alkali metals excel in TSEE yield and advantageous dosimetric properties. The lowest limit of detection - of our BeO:Li TSEE dosimeters (reported at the Third International Conference on Luminescence) was restricted to 10 urad owing to the relative high background of the reading apparatus. We succeeded in developing a low background exoelectron reader in our Institute diminishing the lowest limit of detection to 1 urad, also the reproducibility has been improved. Using the low level TSEE-counter the preirradiation treatment of dosimeters (oxy-hydration) becomes unnecessary. With the system, containing highly sensitive BeO:Li TSEE detectors and the low background TSEE-reader, natural radiation-background dose can be determined after an exposure of some hours. The applicability of the dosimeters is shown by survey data in personnel dosimetry, in monitoring of low radiation level medico-radiological working places as well as in short-term measurements of background radiation. (author)