On the Use of Synthetic Quartz as a Radiation Dosimeter

Quartz obtained from structural materials (bricks, tiles, etc.) is usually employed in retrospective accident dosimetry using the thermoluminescence (TL) technique. However, the TL response can be different depending on the sample due to the different concentration of the impurities in quartz lattice and the glow curves themselves show an enormous variety of shapes. In order to investigate the common properties and the possibility of creating a standard, some members of β-quartz series were synthesized using the ceramic method from precursor powders -Li2CO3, Al(NO3)3.9H2O, Si(C2H5O)4with different compositions and some characteristic features of its TL signal have been studied. The aim of the present work is to provide a basic phenomenological description of the TL response of different 1200C preannealed lithium-aluminium rich beta quartzes (LiAlSiO4, LiAlSi5O12 and LiAlSi16O22) and the dose dependence in the range 0.5-5Gy. A computerized glow curve fitting method based on general order kinetics has been used to characterize the glow curve structure and the trapping parameters for each glow peaks: trap depth (E), frequency factor (s) and the order of kinetics (b). TL emissions were measured in the UV-blue region of the spectrum and, at least, four groups of components at about 80, 95, 110 and 125C have been identified. A fifth peak has been detected in LiAlSiO4 and LiAlSi16O22. The dose dependence of the individual components of the glow curve in the aforementioned range of doses has been also studied. An acceptable linearity can be appreciated in the most stable peaks of the analysed glow curves. These results demonstrate new possibilities offered by the use of synthetic quartz for dosimetric purposes.