Measurement of beta radiation using graphite-mixed thermoluminescent CaSO4:Dy

Abstract New thermoluminescent detectors (TLDs) were prepared from mixtures of CaSO 4 :Dy powder with graphite. The concentration of graphite varied from 0.5 to 20% by weight. The response of these mixed detectors to gamma radiation and to some beta radiation was studied, using 147 Pm, 204 T1, and 90 (Sr/Y) as radiation sources. It was found that the relative beta response of graphite-containing detectors increases, relative to the 60 Co response, with increasing graphite content. Results obtained are discussed and analysed from the points of view of beta radiation detection and dosimetry. Some remarks on the problem gamma-X-beta mixed field dosimetry are also given.