Search

This article reports the characteristics of thermoluminescence (TL) dosimeter of dysprosium doped strontium borate glass for NaO, Li2O, and CaO modifiers imposed by 10–90 Gy dose of 60Co gamma ray irradiation. The different elements are (70.0 – x) B2O3–20SrO–10NaO–xDy2O3, 10Li2O–20SrO–(70 – x)B2O3–(x)Dy2O3 and 10CaO–20SrO–(70.0 – x)B2O3–(x)Dy2O3 (x = 0, 0.10, 0.30, 0.50, 0.70 mol %). The glass was formed by melt quenching method and the ranges of Dy2O3 were 0.0 to 0.7 mol %. Calcium strontium borate doped with 0.3 mol % Dy2O3 shows very good linearity on dose response and gives an excellent sensitivity at 50 Gy dose of 60Co gamma ray irradiation. The samples N1, L1, C3 were completely amorphous. The optimums anneal temperature, time, concentration of Dy2O3 and heating rate were investigated for glass samples N1, L1, C3. The systematic characteristics of glow curve, TL intensity, reproducibility, sensitivity, kinetic parameters and effective atomic number were studied for three selected samples. All samples show the maximum peak from 154–200°C temperatures. [ABSTRACT FROM AUTHOR]

In this article, we investigate thermoluminescence properties of Nd doped silicon dioxide optical fiber. The samples were exposed to 10 MV X-ray using a linear accelerator. The optical fiber was read out using Harshaw 3500 TLD reader. Nd-doped optical fiber displays a linear TL response for the absorbed dose. The sensitivity of Nd-doped optical fiber is 82.87 nC. mg Gy, which is more sensitive to the other types of optical fiber. Nd-doped optical fiber displays clear single glow peak around 180°C. The peak shape method analysis reveals that the peaks obey general order kinetics. The activation energy of Nd-doped optical fiber is found to be nearly 0.5 eV less than TLD-100 (1.6 eV). Z of neodymium-doped silicon dioxide optical fiber is 13.48 that is near to the human bone. All of these TL characteristics indicate that Nd107-doped optical fiber as a potential TL dosimeter, for measuring photon irradiation. [ABSTRACT FROM AUTHOR]

This study investigates and compares the results of thermoluminescence responses, its linearity, sensitivity with various dose ranges and TL glow curve of Fluorine-doped silica fiber and TLD-100 materials. The TL responses of the Fl-doped silica fibers and TLD 100 were kept in gelatin capsule and irradiated with 6-MV photon at the dose range from 0.5 Gy to 4.0 Gy. Siemens model Primus 3368 linear accelerator located at Hospital Sultan Ismail; Johor Bahru has been used to deliver the photon beam to the samples. The TL-signal of TLD 100 media exhibits a significant linear dose to signal relationship with an increase in doses. The sensitivity of Fl-doped optical fiber is negligible to TLD 100 media. [ABSTRACT FROM AUTHOR]

This study addresses the characteristics of Cu-doped and undoped potassium borate glass for use as ionizing radiation dosimeters by investigating and comparing the thermoluminescence responses, linearity, sensitivity and dose response s of the two types of glasses. A number of samples based on xK CO + (100 - x)H BO , where 10 ≤ x ≤ 30 mol.%, have been prepared using a melt quenching technique. The amorphous phases were identified using X-ray diffraction (XRD). The undoped potassium borate samples 20K CO + 80H BO (mol.%) and Cu-doped (0.5 mol.%) samples were placed in a solid phantom apparatus and irradiated with in X-ray tube under 6 MV accelerating voltage with doses ranging from 0.5 to 4.0 Gy. This beam was produced by the Primus MLC 3339 linear accelerator (LINAC) available at Hospital Sultan Ismail, Johor Bahru, Malaysia. The results clearly show the superiority of Cu-doped glass in terms of response and sensitivity to producing luminescence over undoped potassium borate glass. The sensitivity of Cu-doped glass is 6.75 times greater than that of undoped glass. [ABSTRACT FROM AUTHOR]

In this work, we studied the thermoluminescence response of Ge- and Al-doped optical fibers, its linearity, energy dependence, and sensitivity. The Ge-doped optical fibers demonstrate useful TL properties and represent an excellent candidate for use in TL dosimetry of ionizing radiation. The TL response increases monotonically over a wide photon dose range, from 0.2 Gy to 4.0 Gy. The TL results for these fibers have been compared with similar TL data for phosphor TLD-100. Commercially available Al- and Ge-doped optical fibers have both been found to yield a linear dose-TL signal relationship, although the Al-doped fiber provides only 5 % of the sensitivity of the Ge-doped fibers. The TL characteristics of Ge-doped optical fiber, plus its small size (125 μm diameter), high flexibility, ease of handling, and low cost compared with other TL materials, make this commercial optical fiber a very promising TL material for use in medicine, industry, reactor operation, and a variety of other areas. [ABSTRACT FROM AUTHOR]

In this study, thermoluminescence properties of Yb-doped of SiO optical fiber such as linearity, sensitivity and dose response have been investigated. Samples were placed in the gelatin capsules to irradiate with photons from Cobalt-60 of the dose range between 10-100 Gy. The beams were provided by Gammacell 220, available at Universiti Kebangsaan Malaysia, Bangi, Malaysia. The glow curves were analyzed to determine various characteristics of the thermoluminescence. The TL response as a function of dose is linear up to 40 Gy. The sensitivity of Yb-doped optical fiber is 0.136 nC mg Gy. [ABSTRACT FROM AUTHOR]

Abstract: This study investigates the thermoluminescent sensitivity of neodymium doped SiO2 optical fibre with various dose ranges from 0.5Gy to 4.0Gy by 6MeV photon irradiations. The TL responses of the neodymium doped silica fibres are compared with available TLD-100 dosimeter in order to determine the suitability as a TL material. We found that the TLD-100 and neodymium doped silica fibre have a significant linear signal to dose relationship. Neodymium doped fibres sensitivity is approximately 11% of TLD-100. [Copyright &y& Elsevier]

We present the characteristics of the thermoluminescence (TL) response of Ge-doped optical fibers with various energies and exposures of photon irradiation. To investigate the Ge-doped SiO2 as an efficient TL material, the TL responses are compared with commercially available standard TLD100 media. The Ge-doped optical fiber and TLD100 are placed in gelatin capsules and irradiated with x-ray using a Toshiba model KXO-15R x-ray generator. The Ge-doped fiber and TLD-100 show linear response as a function of current and time using x-ray photon of energy 60, 80 and 100 kV. When irradiated with 60, 80 and 100 kV x-ray energy at various currents (mA), tube distance (cm) and exposure time (second) ranges, TLD100 media provide a TL yield up to two times that of Ge-doped fibers. The energy response of the Ge-doped fibers is linear and similar over the 60-100 kV energy range, and its sensitivity is 0.39 ± 0.05 of the TLD100 media. The glow curves of TLD 100 and doped optical fiber are also compared. [ABSTRACT FROM AUTHOR]

We carry out a comparison of the thermoluminescence (TL) response of photon and electron irradiated Ge- and Al-doped SiO2 optical fibres, as well as cross-comparison with that of TLD-100. Irradiation is made with 6MeV electrons and 6 MV photons, for doses ranging from 0.2 Gy to 4.0 Gy. The commercially available Al- and Ge-doped optical fibres produce a linear dose-TL response. The TL yield for both of the doped fibres and also for TLD-100 is greater for electron irradiation than for photon irradiation. The TL yield of the Al-doped fibres is a small fraction of that of Ge-doped fibres (by a factor of 25), the Ge-doped fibres offering a response of 59% of that of TLD-100. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes the thermoluminescence response, sensitivity, stability and reproducibility of SiO2 optical fibres with various electron energies and doses. The TL materials that comprise Al- and Ge-doped silica fibres were used in this experiment. The TL results are compared with those of the commercially available TLD-100. The doped SiO2 optical fibres and TLD-100 are placed in a solid phantom and irradiated with 6, 9 and 12MeV electron beams at doses ranging from 0.2 to 4.0Gy using the LINAC at Hospital Sultan Ismail, Johor Bahru, Malaysia. It was found that the commercially available Al- and Ge-doped optical fibres have a linear dose–TL signal relationship. The intensity of TL response of Ge-doped fibre is markedly greater than that of the Al-doped fibre. [Copyright &y& Elsevier]

Germanium doped calcium borate glasses are investigated in term of thermoluminescence properties to seek their possibility to use as glass radiation dosimeter. The samples were exposed to 6 MV, and 10 MV photon beams in a dose range of 0.5–4.0 Gy. There is a single and broad thermoluminescence glow curve that exhibits its maximum intensity at about 300 °C. Linear dose response behavior has been found in this dose range for the both photon energies. Effective atomic number, TL sensitivity, and reproducibility have also been studied. It is found that the sensitivity of germanium doped sample at 6 MV is only 1.28% and it is superior to the sensitivity at 10 MV. The reproducibility of germanium doped sample is good with a percentage of relative error less than 10%. The results indicate that this glass has a potential to be used as a radiation dosimetry, especially for application in radiotherapy. [ABSTRACT FROM AUTHOR]