title: The effect of ultra-violet and visible radiation on CaSO4:Dy in Teflon discs used for personnel gamma-radiation monitoring.
abstract: The influence of ultra-violet and visible radiation (UV/VIS) on the read-out obtained from the main dosimetry peak of CaSO4:Dy in Teflon discs exposed to the gamma-radiation levels measured by a personnel-monitoring service has been studied as a function of wavelength, irradiance and radiant exposure. The results have been explained by the net effect of three separate factors, namely (i) an inherent response, (ii) a phototransfer and (iii) an optical bleaching. The response obtained from unirradiated discs illuminated with fluorescent room lighting became saturated after 16 hrs at a value corresponding to 0.33 microC kg-1 whilst gamma-irradiated discs faded to 90% of their initial exposure for the same illumination period.
mesh_terms: D002133:Calcium Sulfate; D004419:Dysprosium; D005720:Gamma Rays; D006801:Humans; D008027:Light; D011138:Polytetrafluoroethylene; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation*; D014466:Ultraviolet Rays
chemical_list: D004419:Dysprosium; D011138:Polytetrafluoroethylene; D002133:Calcium Sulfate