Glass-ceramics LiB3O5 – a perspective material for dosimetry (original) (raw)
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Investigation of thermoluminescence properties of metal oxide doped lithium triborate
Journal of Materials Science, 2007
The luminescence properties of several doped materials are explored in many fields of application, including that of ionizing radiation dosimetry. These luminescence properties are essentially provided by the doping element. In this paper, we report TSL measurements of the trapping and recombination centers involved in the luminescence process of sol-gel derived glasses. Three doped species will be concerned: one transition metal (Cu), one rare-earth element (Ce) and a combination of both in the sol-gel silica matrix. By comparing the performances of these samples according to the criteria required for dosimetry by both TSL and OSL (sensitivity, dose-response, thermal fading), the results show that the simply doped samples really are potential candidates for fibered-OSL dosimetry.
Radiation effects in Li2B4O7 oxide crystals
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2000
The lithium tetraborate single crystal has been irradiated by neutrons and the optical properties of these crystals are studied. Irradiation induces optical absorption bands at 42 000, 33 000, and 20 000 cm À1. The intensities of these bands depend on the energy of the neutrons, on the irradiation temperature, and on the presence of an external electric ®eld. An applied electric ®eld induces the displacement of charged particles, creating the micrononhomogeneous regions in the crystal leading to a decrease of the intensities of the absorption bands. It has been established that the irradiation damages not only the surface of the crystal but also the deeper layers.
The effect of synthesis and doping procedures on thermoluminescent response of lithium tetraborate
Journal of Alloys and Compounds, 2011
Lithium tetraborate has been a scientific focus since 1960s by the courtesy of the thermoluminescence property it possesses. Moreover, it is utilized in surface acoustic wave apparatuses, in sensor sector and in laser technology owing to its non-linear optical characteristics. For the uses in thermoluminescence dosimetry lithium tetraborate is activated by addition of a variety of metals as dopants. This study includes the synthesis of lithium tetraborate by two methods (high temperature solid state synthesis and water/solution assisted synthesis), doping of activators into the matrix material synthesized and characterization of the products. Lithium tetraborate is readily commercially available in TL (Themoluminescence) dosimetry; hence, the main aim in this study was to specify the effect of synthesis and doping methods on the TL response. The heating temperature for the synthesis was 750 • C and the retention time as selected as 4 h for both methods. The synthesis stages were followed by doping step where the compounds of Cu, Ag and In in different proportions were doped in lithium tetraborate by solid state and solution assisted doping techniques. Characterization of the product was achieved by X-ray diffraction (XRD), Fourier transform Infra Red Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM) techniques. All samples prepared displayed TL response and the best TL signal was obtained from the sample produced by solid state synthesis and doped by solution assisted method with 0.1% Cu and 0.004% Ag.
Growth and luminescent properties of Li 2 B 4 O 7 single crystal doped with Cu
Journal of Physics: Conference Series, 2009
The authors have primarily succeeded in the study of the technology for growing single crystal Li 2 B 4 O 7 doped with Cu ions by Bridgman technique. The TL-3D spectra show peaks at around 375 nm (3d 9 4s → 3d 10 radiative excitation transition). This success opened up an opportunity in the radiotherapy to manufacture scintillators for neutron detection. The kinetic parameters of thermal stimulation luminescence were investigated by the three point method.
The thermoluminescent properties of lithium triborate (LiB 3O 5) activated by aluminium
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2008
In this paper, the thermoluminescence (TL) dosimetric characteristics of Al-doped LiB 3 O 5 compounds are presented. The powder samples were prepared by the solid-state reaction method and the formation of the compounds were confirmed by an X-ray diffraction study. The TL studies of undoped and Al-doped LiB 3 O 5 samples showed similar glow curve structures. They have three TL glow peaks at about 60, 130 and 200°C after heating at a constant heating rate of 1°C/s. Their comparative TL studies indicated that 5 wt% Al-doped LiB 3 O 5 compound was approximately 240 times more sensitive than undoped compound. The TL emission spectra of Al-doped LiB 3 O 5 showed a maximum band at around 520 nm. The main dosimetric characteristics, which are namely the TL dose response, TL sensitivity, fading, minimum detectable dose, reproducibility, precision of dose measurement and annealing procedure, indicated that Al-doped LiB 3 O 5 sample, can be used in dosimetric applications. The trap parameters namely order of kinetics (b), activation energy (E) and frequency factor (s) associated with the glow peaks in beta irradiated undoped and Al-doped LiB 3 O 5 samples were obtained by glow curve deconvolution (GCD) program.
Journal of Alloys and Compounds, 2011
Lithium tetraborate: Li 2 B 4 O 7 , (LTB) has been synthesized and doped with various Mn content by different methods, such as, high temperature solid state synthesis and solution assisted synthesis methods. Powder XRD results proved the formation of solid-solution by replacing Mn with Li ions in LTB lattice at lower amount of Mn doping, for example 0.1-3.0% Mn doping. In this research TL glow curves of Mn doped lithium tetraborate (LTB:Mn) produced by using different synthesis and doping methods and the effects of Ag, P and Mg as co-dopant were investigated. Structural and morphological analyses of products were done by using Fourier Transform Infrared spectroscopy (FTIR), Powder X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Raman Spectroscopy.
In this paper, the thermoluminescence (TL) dosimetric characteristics under beta-ray, x-ray and gamma-ray excitations of powder and pellet Mn-doped lithium tetraborates (LTB) which were produced by solution combustion synthesis technique were investigated, and the results were compared with that of TLD-100 chips. The chemical composition and morphologies of the obtained LTB and Mn-doped LTB (LTB: Mn) were confirmed by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) and scanning electron microscopy (SEM) with EDX. LTB:Mn was studied using luminescence spectroscopy. In addition, the effects of sintering and annealing temperatures and times on the thermoluminescence (TL) properties of LTB:Mn were investigated. The glow curves of powder samples as well as pellet samples exposed to different beta doses exhibited a low temperature peak at about 100 °C followed by an intense principal high temperature peak at about 260 °C. The kinetic parameters (E, b, s) associated with the prominent glow peaks were estimated using T m –T stop , initial rise (IR) and computerized glow curve deconvolution (CGCD) methods. The TL response of integral TL output increased linearly with increasing the dose in the range of 0.1–10 Gy and was followed by a superlinearity up to 100 Gy both for powder and pellet samples using beta-rays. Powder and pellet LTB:Mn were irradiated to a known dose by a linear accelerator with 6 and 18 MV photon beams, 6–15 MeV electron beams and a traceable 137 Cs beam to investigate energy response. Further, TL sensitivity, fading properties and recycling effects related with beta exposure of LTB:Mn phosphor were evaluated and its relative energy response was also compared with that of TLD-100 chips. The comparison of the results showed that the obtained phosphors have good TL dose response with adequate sensitivity and linearity for the measurement of medical doses.