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TL glow curve of a pure silica flat optical fiber subjected to 1.0 kGy to 1.0 MGy of synchrotron irradiation with the peak temperature of 328 o C
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The research and development efforts on the silica (SiO2) optical fiber for application in radiation sensing and other dosimetry field have become quite active. The widely used LiF based dosimeter (TLD) has shown a relatively low reproducibility and there is a time delay in dose assessment which loses its capability as direct real-time dose assessm...
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Citations
... The response of these has been compared against that of tailor made optical fibres; flat Ge-B doped fibres (FF) and fibres of cylindrical construction, the latter in the form of a Photonic Crystal Fibre (PCF). The elemental concentration of Ge-B FF and Ge-B PCF samples via energy dispersive x-ray fluorescence (SEM-EDXRF) has been reported by Alawiah et al. (2013) and Rozaila et al. (2016) respectively. In % terms, these were for the former: Si (54.98%); O (38.45%); Ge (0.34%); B (6.23%) and for the latter: Si (50.18%); O (30.25%); Ge (1.34%); B (18.23%). ...
... Tailor-made Ge-doped FFs of various dimension were later studied (Noramaliza et al., 2016), irradiated by 60 Co gamma-rays (mean energy 1.25 MeV) at doses from 1 to 10 kGy, producing dose response linearity correlation (regression) coefficients R 2 of from 0.80 to 0.93. High dose-rate irradiations of fabricated Ge-B doped FF have also been carried out using a synchrotron electron beam, for doses 1-500 kGy and also 1 MGy, producing supralinearity of TL dose response from 5 kGy up to 100 kGy (Alawiah et al., 2013). In contradistinction, herein it is apparent that relative to the TL response of the other investigated dosimetric materials, that of the borosilicate glass slides is sufficiently low in sensitivity that a non-saturated highly linear response is obtained throughout the dose range 25 kGy-250 kGy, producing an R 2 value of 0.980 (Fig. 2). ...
Thermoluminescence dosimetry most typically concerns the sensing and quantification of ionizing radiation exposures, with evaluation of absorbed dose arising from electron-hole trapping in well-disposed insulating/ semi-conducting media. In this passive form of dosimetry the signal derives from photons released post-irradiation heating of the dosimeter over a specific temperature range. Herein, for entrance doses from 2 Gy up to 250 kGy, investigation is made of the thermoluminescence properties of electron irradiated borosilicate glass (SiO 2-B 2 O 3), the samples deriving from commercial microscope slides (coverslips) of thickness 1.0 mm. The coverslips provide linear TL response over a wide range of radiation dose, through use of a clinical linear accelerator in a lower dose regime (2-10 Gy) and use of a product-irradiation electron linac in a higher dose regime (25 kGy-250 kGy), obtaining a regression coefficient in excess of 96%. In the high dose regime comparison has been made with the response of Ge-B doped Flat Fibre (FF) and Ge-B doped photonic crystal fibre (PCF) (collapsed). Deconvolution shows the glow curves of the borosilicate glass to be formed of five overlapping peaks, with figures of merit (FOM) of between 0.62-1.72 and 0.87-1.00 for the particular dose ranges 2-10 Gy and 25 kGy-250 kGy respectively. Through use of Glowfit deconvolution software, the key trapping parameters of activation energy and frequency factor were calculated for the borosilicate glass slide.
... Several materials such as germanium [10], [53]- [57], boron [52], [58], aluminum [54], [59], [60], phosphorus [61], and This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. ...
In this paper, we review the highly promising silica glass, fabricated as doped and undoped optical fiber for intended use in radiation dosimetry. The dosimetry techniques reviewed here, underpinned by intrinsic and extrinsic defects in silica glass, focus on Thermoluminescence (TL), Optically Stimulated Luminescence (OSL) and Radioluminescence (RL), with occasional references to the much more established Radiation Induced Attenuation (RIA). The other focus in this review is on the various materials that have been reported earlier as dopants and modifiers used in silica glass optical fiber radiation dosimeters. This article also elaborates on recently reported optical fiber structures, namely, cylindrical fibers, photonic crystal fibers and flat fibers, as well as dimensions and shapes used for optimization of dosimeter performance. The various types of optical fiber radiation dosimeters are subsequently reviewed for various applications ranging from medical dosimetry such as in external beam radiotherapy, brachytherapy and diagnostic imaging, as well as in industrial processing and space dosimetry covering a dynamic dose range from μGy to kGy. Investigated dosimetric characteristics include reproducibility, fading, dose response, reciprocity between luminescence yield to dose-rate and energy dependence. The review is completed by a brief discussion on limitations and future developments in optical fiber radiation dosimetry.
... An additional form of glass based dosimeter that has attracted considerable and growing attention are silica-based optical fibres , offering a range of advantages over other passive dosimeter types. These include high spatial resolution, by virtue of their very small size ( $ 125 mm) relative to many other forms of dosimeter, linear dose response in both the low and high dose regimes (Alawiah et al., 2013a(Alawiah et al., , 2013bGirard et al., 2013), capability for real time remote monitoring (Fernandez et al., 2008;O'Keeffe et al., 2007), lower cost (Espinosa et al., 2006) and relatively high dose sensitivity . ...
