2 research outputs found
Latest developments in silica-based thermoluminescence spectrometry and dosimetry
Using irradiated doped-silica preforms from which fibres for thermoluminescence dosimetry applications can be fabricated we have carried out a range of luminescence studies, the TL yield of the fibre systems offering many advantages over conventional passive dosimetry types. In this paper we investigate such media, showing emission spectra for irradiated preforms and the TL response of glass beads following irradiation to an Am-241-Be neutron source located in a tank of water, the glass fibres and beads offering the advantage of being able to be placed directly into liquid. The outcomes from these and other lines of research are intended to inform development of doped silica radiation dosimeters of versatile utility, extending from environmental evaluations through to clinical and industrial applications. (C) 2015 Elsevier Ltd. All rights reserve
Developments in production of silica based thermoluminescence dosimeter
This work addresses purpose-made thermoluminescence dosimeters (TLD) based on doped silica fibres
and solโgel nanoparticles, produced via Modified Chemical Vapour Deposition (MCVD) and wet chemistry
techniques respectively. These seek to improve upon the versatility offered by conventional phosphor-based
TLD forms such as that of doped LiF. Fabrication and irradiation-dependent factors are seen to
produce defects of differing origin, influencing the luminescence of the media. In coming to a close, we
illustrate the utility of Ge-doped silica media for ionizing radiation dosimetry, first showing results from
gamma-irradiated Ag-decorated nanoparticles, in the particular instance pointing to an extended dynamic
range of dose. For the fibres, at radiotherapy dose levels, we show high spatial resolution (0.1 mm)
depth-dose results for proton irradiations. For novel microstructured fibres (photonic crystal fibres, PCFs)
we show first results from a study of undisturbed and technologically modified naturally occurring
radioactivity environments, measuring doses of some 10 s of ฮผGy over a period of several months