Ge and B doped collapsed photonic crystal optical fibre, a potential TLD material for low dose measurements. (September 2016)

• Record Type: Journal Article
• Authors: Rozaila, Z. Siti; Alyahyawi, Amjad; Khandaker, M.U.; Amin, Y.M.; Bradley, D.A.; Maah, M.J.
• Is Part Of: Radiation physics and chemistry. Volume 126(2016:Sep.)
• Page Start: 9
• Page End: 13
• Publication Date: 2016-09
• Subjects: Thermoluminesence -- Photonic crystal fibre -- Dose and energy response -- Effective atomic number; Radiation chemistry -- Periodicals; Radiometry -- Periodicals; Radiation -- Periodicals; Chimie sous rayonnement -- Périodiques; 539.2
• DOI: 10.1016/j.radphyschem.2016.04.021
• Languages: English
• ISSNs: 0969-806X

Abstract

Abstract: Offering a number of advantageous features, tailor-made silica-based fibres are attracting attention as thermoluminesence (TL) dosimeters. We have performed a detailed study of the TL properties of Ge-doped and Ge-B-doped collapsed photonic crystal fibres (PCFc), most particularly with regard to their potential use for the environmental and X-ray diagnostic dose monitoring. Extrinsic doping and defects generated by strain at the fused inner walls of the collapsed fibres result in the PCFc-Ge-B and PCFc-Ge fibres producing markedly greater TL response than that of the phosphor-based dosimeter TLD-100, by some 9 and 7×, respectively. The linearity of TL yield has been investigated for X-ray doses from 0.5 mGy to 10 mGy. For a dose of 1 Gy, the energy response of the PCFs and TLD-100 has been studied using X-rays generated at accelerating potentials from 20 kVp through to 200 kVp and for the 1.25 MeV mean gamma-ray energy from 60 Co. The effective atomic number, Z eff of PCFc-Ge and PCFc-Ge-B was estimated to be 12.5 and 14.4, respectively. Some 35 days post-irradiation, fading of the stored TL signal from PCFc-Ge-B and PCFc-Ge were found to be ∼15% and 20% respectively, with mean loss in TL emission of 0.4–0.5% per day. The present doped-silica collapsed PCFs provide greatly improved TLD performance compared to that of previous fibre designs and phosphor-based TLD-100. Highlights: We study Ge and GeB doped Photonic Crystal Fibre (PCF) dosimeters for low dose measurements. The irradiation response of PCF dosimeters to X-rays and gamma-rays are described. The presence of boron manifestly improves the sensitivity of the PCF dosimeters.