The application of radiophotoluminescent glass to γ dosimetry in mixed n-γ fields

High Z radiophotoluminescent glass of British manufacture has been studied with a view to using it as a γ ray dosemeter in mixed n-γ fields at ambient and elevated temperatures. Environments such as these are widespread amongst nuclear engineering, accident dosimetry and military application areas. The radiation response of the glass has been fully characterised and the results are presented. The photon response over the energy range 16 keV-7 MeV has been determined and interpreted within the framework of a simplified model. The neutron response from thermal energies to 15 MeV has been measured using reactor and accelerator based sources. The fast neutron response was found to be small, although the thermal neutron sensitivity is too high for most in-core applications without a thermal neutron shield. The results are also compared with new measurements of the neutron response of Toshiba FD7 glass over the energy range thermal - 2.2 MeV. The signal build-up and fade characteristics of the dosemeter at ambient temperatures and 1000C are presented for irradiations carried out both at ambient and 1000C. Acceptable stability is found at these elevated temperatures. The potential use of this high Z glass in tandem with low Z beryllium oxide dosemeters as a measure of gamma ray spectra is also discussed. (author)