Synthesis of MgB4O7:Dy3+and Thermoluminescent Characteristics at Low Doses of Beta Radiation

The synthesis and thermoluminescent characteristics of dysprosium-doped MgB4O7 are analyzed. The phosphor at different concentrations (0, 0.1, 0.5, 1, 2 and 4 mol%) of the dopant was prepared by the solution-assisted method. The magnesium borate compound was confirmed by X-ray diffraction. The annealing and dopant concentrations effects on the crystalline matrix were investigated. The highest thermoluminescent sensitivity was found with 450°C of annealing temperature and at high Dy3+ concentration too. The un-doped MgB4O7 phosphor shows a broad glow curve which peaked at 199°C and about 306 °C. Introducing Dy3+ dopant in the matrix that behavior was strongly changed. The wide glow curve shows three glow peaks; two small shoulders at 124 and 195 °C, and a highest peak between 323 and 336 °C temperature range. A large linear dose-response (5 – 2000 mGy) beta dose was obtained. The complex glow curves were deconvolved and the kinetics parameters were determined considering the general order kinetics model

Synthesis and TL Characterization of Li2B4O7 Doped with Cooper and Manganese

Copper (Cu) and manganese (Mn) doped tissue equivalent Li2B4O7 were prepared by solid state sintering. The glow curves shows a high temperature peak at 222 °C for Li2B4O7:Cu and for Li2B4O7:Mn at 218 °C. Linear dose response is observed up to 140 Gy. With a thermal treatment at 125 °C, the first peak of the phosphors doped with copper (95 °C) and manganese (90 °C) disappears and the main TL peaks remain isolated. The dose rate dependence was studied by exposing the samples at doses of 25 Gy and 250 Gy. At low dose it was observed that the Li2B4O7:Cu TL response has non-dependence on dose rate, and at higher dose was observed that there is a dependence of the TL response with the different dose rateFil: Guarneros Aguilar, C.. Benemérita Universidad Autónoma de Puebla. Facultad de Ciencias Físico-Matemáticas. Posgrado en Física Aplicada; MéxicoFil: Cruz Zaragoza, E.. Universidad Nacional Autónoma de México. Instituto de Ciencias Nucleares. Unidad de Irradiación y Seguridad Radiológica; MicronesiaFil: Marcazzo, Salvador Julian. Universidad Nacional del Centro de la Provincia de Bs.as.. Facultad de Ciencias Exactas. Instituto de Fisica Arroyo Seco; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil; ArgentinaFil: Palomino Merino, R.. Benemérita Universidad Autónoma de Puebla. Facultad de Ciencias Físico-Matemáticas. Posgrado en Física Aplicada; MéxicoFil: Espinosa, J.. Benemérita Universidad Autónoma de Puebla. Facultad de Ciencias Físico-Matemáticas. Posgrado en Física Aplicada; Méxic

Radio-Optically- and Thermally Stimulated Luminescence of Zn(BO2)2:Tb3+ exposed to Ionizing Radiation

The optical absorption of zinc tetraborate at different concentrations of the terbium impurity (0, 0.5, 1, 2, 4, 8 mol%) was analyzed. The radioluminescence (RL) emission spectra was obtained after beta irradiation of a 90Sr/90Y source. The RL spectrum showed the characteristics bands of Tb3+ with two main emissions at 489 nm and 546 nm which corresponding to the5D4→7F6 and 5D4→7F5 transitions respectively in this ion. The OSL and TL characteristics have been analyzed. The stimulation blue light (497 nm) of a diode laser at 500 mA was used to bleach the thermoluminescent (TL) signals obtained with 5Gy of 60Co source. The two main glow peaks (79 and 161 °C) are sensitives under 497 nm stimulation, and they were shifted to higher temperature values and faded their TL intensities. Similar behavior of TL glow curves before and after OSL stimulation with blue light was observed when the samples were exposed to 30 Gy gamma dose of 137Cs irradiator. The OSL signal response was linear with the dose range of 1-10 Gy and increased their response up to 200 Gy gamma dose. The OSL shows a bleaching sensitive shallow traps and diminishing the intensity of the TL glow curves remaining a complex traps distribution. The RL, TL and OSL properties were investigated in Zn(BO2)2:Tb3+ phosphor

Characterization of a fiberoptic radiotherapy dosimetry probe based on Mg2SiO4:Tb

In this work the feasibility of using Mg2SiO4:Tb as a fiberoptic radioluminescent (RL) dosimetry probe for real-time dosimetry has been investigated for the first time. In particular, the stability of the RL signal after repeated use, the spectrum of the RL emission and the dose-rate response curve of a Mg2SiO4:Tb-based fiberoptic probe have been determined. The probe has been also used to obtain a percentage dose depth curve in a water phantom and its performance has been compared to that of a standard ion chamber. Besides, its absolute RL yield has been compared to that of an RL probe based on the commercial Al2O3:C phosphor. (C) 2009 Elsevier Ltd. All rights reserved

Analysis of thermoluminescence kinetics of Mg2SiO4:Tb compounds employing an interactive model

The kinetics involved in the thermoluminescence (TL) of Mg2SiO4:Tb compounds has been investigated by unfolding glow curves employing both the General Order model and a model that takes into account interactions among traps. The dependence of the glow curve shape on dose is only correctly described if interaction among traps is included in the analysis. (C) 2009 Elsevier B.V. All rights reserved

Optically stimulated luminescence of natural NaCl mineral from Dead Sea exposed to gamma radiation

In this work, the continuous wave - optically stimulated luminescence (CW-OSL) emissions of natural salt minerals, collected from Dead Sea in summer of 2015, were studied. The CW-OSL dose response of natural salt showed a linear range between 0.5 Gy and 10 Gy of gamma radiation of 60Co. Samples exposed at 3 Gy exhibited good repeatability with a variation coefficient of 4.6%. The CW-OSL response as function of the preheating temperature (50–250 °C) was analyzed. An increase of 15% of the CW-OSL response was observed in NaCl samples during storage period of 336 h. The results showed that the natural Dead Sea salt minerals could be applied as natural dosimeter of gamma radiation.Fil: Roman Lopez, J.. Universidad Nacional Autónoma de México. Instituto de Ciencias Nucleares; México. Consejo Nacional de Ciencia y Tecnología; MéxicoFil: Piña López, Y. I.. Universidad Nacional Autónoma de México; MéxicoFil: Cruz Zaragoza, Epifanio. Universidad Nacional Autónoma de México. Instituto de Ciencias Nucleares; MéxicoFil: Marcazzo, Salvador Julian. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Fisica Arroyo Seco; Argentin

Photo-, radio- and thermoluminescence of Sm3+Sm^ {3+} doped and Tb3+Tb^ {3+}/Sm3+Sm^ {3+} doubly doped K2K_{2}YF5F_{5} single crystals

Photoluminescence, radioluminescence and thermoluminescence properties of K2YF5 crystals containing different concentrations of samarium and terbium ions have been investigated for the first time. It has been found that the emission peaks observed in ranges from 300 to 550 nm and from 550 to 750 nm can be attributed to the 4f–4f transitions of the Tb3+ ions and the Sm3+ ions, respectively, for both photoluminescence and radioluminescence. The maximum of light output for radioluminescence under beta irradiation has been obtained for K2YF5 crystals doped with 1.0 at% Sm3+ ions and the prospects for using such dosimeters in fiber optic dosimetry have been evaluated. On the other hand, it has been found that the glow curves of doubly doped fluoride crystals are made up of at least four overlapping glow peaks and that K2YF5:1.0 at% Tb3+; 0.5 at% Sm3+ crystals show the most intense thermoluminescence emission.Fil: Marcazzo, Salvador Julian. Universidad Nacional del Centro de la Provincia de Bs.as.. Facultad de Ciencias Exactas. Instituto de Fisica Arroyo Seco; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil; ArgentinaFil: Santiago, Martin Alejo. Universidad Nacional del Centro de la Provincia de Bs.as.. Facultad de Ciencias Exactas. Instituto de Fisica Arroyo Seco; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil; ArgentinaFil: Makhov, V. N.. Lebedev Physical Institute; RusiaFil: Tuyen, Vu Phi. Institute of Materials Science; VietnamFil: Khaidukov, N. M.. Kurnakov Institute of General and Inorganic Chemistry; RusiaFil: Caselli, Eduardo Eladio. Universidad Nacional del Centro de la Provincia de Bs.as.. Facultad de Ciencias Exactas. Instituto de Fisica Arroyo Seco; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentin

Thermoluminescence study of polyminerals extracted from clove and marjoram for detection purposes

Food irradiation is a widely employed technology for food treatment. Since in several countries no regulations prevail, it is difficult to detect whether food has been irradiated or not. Among different analytical methods the study of the thermoluminescent (TL) emission of polymineral extracted from food is one of the most useful physical identification method. The aim of this work is to analyze the TL properties of inorganic polyminerals extracted from commercial clove (Syzygium aromaticum L.) and marjoram (Origanum majorana L.) spices exposed to 60Co gamma radiation for detection purposes. The feasibility of using the TL method for irradiated food detection and absorbed dose determination is assessed.Fil: Marcazzo, Salvador Julian. Universidad Nacional Autónoma de México; México. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Fisica Arroyo Seco; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cruz Zaragoza, Epifanio. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Fisica Arroyo Seco; ArgentinaFil: Mendoza, J. E.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Fisica Arroyo Seco; ArgentinaFil: Ramos Reyes, E.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Fisica Arroyo Seco; ArgentinaFil: Brown, Fabian Emilio. Universidad de Sonora; Méxic