1,720,984 research outputs found
On Energy Absorption Effects In Uranium And Thorium Thin Films
No full textThe use of U and Th thin films, attached to detectors of fission tracks, allows determining the neutron fluence in nuclear reactors. In principle, the parameters involved in neutron fluence determinations through U and Th thin films that might be influenced by effects related with fission fragments and α particle energy absorption are: (i) the detection efficiency of nuclear emulsions for α particles, (ii) the detection efficiency of muscovite mica for fission fragments from thin films, ε{lunate}F and (iii) the detection efficiency of nuclear emulsions for fission fragments, used to estimate ε{lunate}F. Fission fragments are more ionizing than α particles and are more influenced by energy absorption. We show that fission fragment energy absorption effects are negligible in case of U and Th thin films employed in neutron fluence determinations for fission-track (FT) dating. © 2008.43SUPPL.1S334S336Bigazzi, G., Hadler, J.C., Iunes, P.J., Osorio, A.M., Muscovite SSNTD: detection efficiency for fission fragments (1991) Nucl. Tracks Radiat. Meas., 19, pp. 451-452Bigazzi, G., Guedes, S., Hadler, J.C., Iunes, P.J., Oddone, M., Osorio, A.M., Paulo, S.R., Zúniga, A., Potentialities and practical limitations of an absolute neutron dosimetry using thin films of uranium and thorium applied to the fission track method (1999) Radiat. Meas., 31, pp. 651-656Hadler, J.C., 1979. Estudos sobre Traços Anômalos Observados em Emulsões Carregadas com Urânio. Master Thesis, Universidade Estadual de Campinas, Campinas SP, BrazilHadler, J.C., Iunes, P.J., Mello, T.C.W.P., Navia, L.M.S., Paulo, S.R., On the nuclear emulsion detection efficiency for alpha particles and fission fragments (1996) Radiat. Meas., 26, pp. 169-171Iunes, P.J., Hadler, J.C., Bigazzi, G., Tello, C.A., Guedes, S., Paulo, S.R., Durango apatite fission-track dating using length-based age corrections and neutron fluence measurements by thorium thin films and natural U-doped glasses calibrated through natural uranium thin films (2002) Chem. Geol., 187, pp. 201-211Iunes, P.J., Hadler, J.C., Bigazzi, G., Guedes, S., Zúñiga, A., Paulo, S.R., Tello, C.A., Uranium and thorium film calibrations by particle track techniques (2004) J. Radioanal. Nucl. Chem., 262, pp. 461-468Iunes, P.J., Bigazzi, G., Hadler, J.C., Laurenzi, M.A., Balestrieri, M.L., Norelli, P., Osório, A.M., Curvo, E.A.C., U and Th thin film neutron dosimetry for fission-track dating: application to the age standard Moldavite (2005) Radiat. Meas., 39, pp. 665-668Osório, A.M., Iunes, P.J., Bigazzi, G., Hadler, J.C., Laurenzi, M.A., Norelli, P., Tello, C.A., Paulo, S.R., Fission-track dating of macusanite glasses with plateau and size correction methods (2003) Radiat. Meas., 36, pp. 407-412Segrè, E., Wiegand, C., Stopping power of various substances for fission fragments (1946) Phys. Rev., 70, pp. 808-81
Group Analysis Method For Fission Track Thermochronology
No full textA methodology to obtain ages and thermal histories of sets of apatite samples from localities with geologically compatible characteristics is described. A methodology exploring the fact that samples with similar geological characteristics should present the same thermal history is proposed. This approach can contribute for the obtainment of more conclusive results by analysing fewer samples than it is necessary when the samples are individually analysed. In order to determine the ages, we use the absolute neutron dosimetry through thin films of natural uranium along with λf = 8.46 × 10- 17 a- 1. As an example of application of the proposed methodology, we analyse samples collected in a Brazilian region, São Francisco Craton, which experienced low tectonic activity. © 2008 Elsevier Ltd. All rights reserved.43SUPPL.1S163S168Barbarand, J., Hurford, T., Carter, A., Compositional and structural control of fission-track annealing in apatite (2003) Chem. Geol., 198, pp. 107-137Bevington, P.R., (1969) Data Reduction and Error Analysis for the Physical Sciences, , Mc Graw-Hill, New YorkBigazzi, G., Hadler, J.C., Iunes, P.J., Osorio, A.M., Muscovite SSNTD: detection efficiency for fission fragments (1991) Radiat. Meas., 19, pp. 451-452Bigazzi, G., Guedes, S., Hadler, J.C., Iunes, P.J., Oddone, M., Osorio, A.M., Paulo, S.R., Zúniga, A., Potentialities and practical limitations of an absolute neutron dosimetry using thin films of uranium and thorium applied to the Fission Track Method (1999) Radiat. Meas., 31, pp. 651-656Carlson, W.D., Mechanisms and kinetics of apatite fission-track annealing (1990) Am. Mineral., 75, pp. 1120-1139Carlson, W.D., Donelick, R.A., Ketcham, R.A., Variability of apatite fission-track annealing kinetics I: experimental results (1999) Am. Mineral., 84, pp. 1213-1223Crowley, K.D., Cameron, M., Shaefer, R.L., Experimental studies of annealing of etched fission tracks in fluor apatite (1991) Geochim. Cosmochim. Acta, 55, pp. 1449-1465Fleischer, R.L., Hart, H.R., Fission track dating techniques and problem (1972) Calibration of Humanoid Evolution, pp. 135-170. , Bishop W.W., Miller J.A., and Cole S. (Eds), Scottish Academic Press, EdinburgFleisher, R.L., Price, P.B., Charged particle tracks in glass (1963) J. Appl. Phys., 34, pp. 2903-2904Franco, A.O.B., Hackspacher, P.C., Godoy, D.F., Ribeiro, L.F.B., Guedes, S., História térmica do Maciço Alcalino de Poços de Caldas (SP/MG) e adjacências através da análise de datação por traços de fissão em apatitas (2005) Rev. Bras. Geociênc., 35, pp. 351-358Gleadow, A.J.W., Fission track dating methods: what are the real alternatives? (1981) Nucl. Tracks, 5, pp. 3-14Green, P.F., Duddy, I.R., Gleadow, A.J.W., Tingate, P.R., Laslett, G.M., Thermal annealing of fission tracks in apatite, 1. The qualitative description (1986) Chem. Geol. Isot. Geosci. Sect., 59, pp. 237-253Green, P.F., Duddy, I.R., Laslett, G.M., Hegarty, K.A., Gleadow, A.J.W., Lovering, J.F., Thermal annealing of fission tracks in apatite 4. Quantitave modeling techniques and extension to geological time scale (1989) Chem. Geol. Isot. Geosci. Sect., 79, pp. 155-182Guedes, S., Hadler, J.C., Iunes, P.J., Paulo, S.R., Zúñiga, A., The spontaneous fission decay constant of 238U using SSNTD (2000) J. Radioanal. Nucl. Chem., 245, pp. 441-442Guedes, S., Hadler, J.C., Iunes, P.J., Zúñiga, A., Tello, C.A., Paulo, S.R., The use of the U (n, f) reaction dosimetry in the determination of the λf value through fission-track techniques (2003) Nucl. Instrum. Methods A, 496, pp. 215-221Guedes, S., Hadler, J.C., Iunes, P.J., Oliveira, K.M.G., Kakazu, M.H., Sarkis, J.E.S., Paulo, S.R., Tello, C.A., Spontaneous-fission decay constant of 238U measured by nuclear track techniques without neutron irradiation (2003) J. Radioanal. Nucl. Chem., 258, pp. 117-122Guedes, S., Hadler, J.C., Iunes, P.J., Tello, C.A., Kinetic model for the relationship between confined fission-track length shortening and fission-track age reduction in minerals (2004) Nucl. Instrum. Methods B, 217, pp. 627-636Guedes, S., Hadler, J.C., Iunes, P.J., Oliveira, K.M.G., Moreira, P.A.F.P., Tello, C.A., Kinetic model for the annealing of fission tracks in zircon (2005) Radiat. Meas., 40, pp. 517-521Guedes, S., Hadler, J.C., Oliveira, K.M.G., Moreira, P.A.F.P., Iunes, P.J., Tello, C.A., Kinetic model for the annealing of fission tracks in minerals and its application to apatite (2006) Radiat. Meas., 41, pp. 392-398Guedes, S., Curvo, E.A.C., Tello, C.A., Hadler, J.C., Iunes, P.J., Paulo, S.R., Palissari, R., On the annealing of fission tracks in randomly oriented grains of apatite (2007) Nucl. Instrum. Methods B., 256, pp. 683-692Hadler, J.C., Paulo, S.R., Iunes, P.J., Tello, C.A., Balestrieri, M.L., Bigazzi, G., Curvo, E.A.C., Hackspacher, P.C., A PC compatible Brazilian software for obtaining thermal histories using apatite fission track analysis (2001) Radiat. Meas., 34, pp. 149-154Hadler, J.C., Bigazzi, G., Guedes, S., Iunes, P.J., Oddone, M., Tello, C.A., Paulo, S.R., Spontaneous 238U fission half-life measurements based on fission-track techniques (2003) J. Radioanal. Nucl. Chem., 256, pp. 155-157Harman, R., Gallagher, K., Brown, R., Raza, A., Bizzi, L., Accelerated denudation and tectonic/geomorphic reactivation of the cratons of northeast Brazil during the Late Cretaceous (1998) J. Geophys. Res., 103, pp. 27091-27105Holden, N.E., Hoffman, D.C., Spontaneous fission half-lives for ground-state nuclides (Technical Report) (2000) Pure Appl. Chem., 72, pp. 1525-1562Hurford, A.J., Standardization of fission track dating calibration: recommendation by the fission track working group of the I. U.G.S. Subcommission on Geochronology (1990) Chem. Geol. Isot. Geosci. Sect., 80, pp. 171-178Iunes, P.J., Hadler, J.C., Bigazzi, G., Tello, C.A., Guedes, S., Paulo, S.R., Durango apatite fission-track dating using length-based age corrections and neutron fluence measurements by thorium thin films and natural U-doped glasses calibrated through natural uranium thin films (2002) Chem. Geol., 187, pp. 201-211Iunes, P.J., Bigazzi, G., Hadler, J.C., Tello, C.A., Guedes, S., Paulo, S.R., Balestrieri, M.L., Zúñiga, A., The Th/U ratio in minerals by a fission track technique: application to some reference samples in order to estimate the influence of Th in fission-track dating (2002) Radiat. Meas., 35, pp. 195-201Iunes, P.J., Hadler, J.C., Bigazzi, G., Guedes, S., Zúñiga, A., Paulo, S.R., Tello, C.A., Uranium and thorium film calibrations by particle track techniques (2004) J. Radioanal. Nucl. Chem., 262, pp. 461-468Iwano, H., Danhara, T., A re-investigation of the geometry factors for fission-track dating of apatite, sphene and zircon (1998) Advances in Fission-Track Geochronology, pp. 47-66. , Van den haute P., and De Corte F. (Eds), Kluwer Academic Publishers, DordrechtJonckheere, R., On the densities of etchable fission tracks in a mineral and co-irradiated external detector with reference to fission-track dating of minerals (2003) Chem. Geol., 200, pp. 41-58Ketcham, R.A., Donelick, R.A., Carlson, W.D., Variability of apatite fission-track annealing kinetics III: extrapolation to geological time scales (1999) Am. Mineral., 84, pp. 1224-1234Laslett, G.M., Galbraith, R.F., Statistical modeling of thermal annealing of fission tracks in apatite (1996) Geochim. Cosmochim. Acta, 60, pp. 5117-5131Laslett, G.M., Green, P.F., Duddy, I.R., Gleadow, A.J.W., Thermal annealing of fission tracks in apatite 2. The quantitative analysis (1987) Chem. Geol. Isot. Geosci. Sect., 65, pp. 1-13Lutz, T.M., Omar, G., An inverse method of modeling thermal histories from apatite fission-track it dates (1991) Earth Planet. Sci. Lett., 104, pp. 181-195Nóbrega, M.A., Sá, J.M., Bezerra, F.H.R., Hadler, J.C., Iunes, P.J., Guedes, S., Tello, C.A., Lima-Filho, F.P., The use of apatite fission track thermochronology to constrain fault movements and sedimentary basin evolution in northeastern Brazil (2005) Radiat. Meas., 39, pp. 627-633Osório, A.M., Iunes, P.J., Bigazzi, G., Hadler, J.C., Laurenzi, M.A., Norelli, P., Tello, C.A., Paulo, S.R., Fission-track dating of Macusanite glasses with plateau and size correction methods (2003) Radiat. Meas., 36, pp. 407-412Price, P.B., Walker, R.M., Fossil tracks of charged particles in mica and the age of the minerals (1963) J. Geophys. Res., 68, pp. 4847-4862Silva, A.B., Liberal, G.S., Grossi Sad, J.H., Issa Filho, A., Rodrigues, C.S., Riftel, B.F., Geologia e petrologia do complexo Angico dos Dias (Bahia, Brazil), uma assiciação carbonatítica precanbriana (1988) Geochimica Bras., 2 (1), pp. 81-108Storzer, D., Poupeau, G., Ages-plateaux de minéraux et verres par la méthode des traçes de fission (1973) C. R. Acad. Sci. Paris D, 276, pp. 137-139Storzer, D., Wagner, G.A., Correction of thermally lowered fission track ages of tektites (1969) Earth Planet. Sci. Lett., 5, pp. 463-468Tello, C.A., Hadler, J.C., Iunes, P.J., Guedes, S., Hackspacher, P.C., Ribeiro, L.F.B., Paulo, S.R., Osorio, A.M., Thermochronology of the South American platform in the state of São Paulo, Brazil, through apatite fission tracks (2005) Radiat. Meas., 39, pp. 635-640Tello, C.A., Palissari, R., Hadler, J.C., Iunes, P.J., Guedes, S., Curvo, E.A.C., Paulo, S.R., Annealing experiments on induced fission tracks in apatite: measurements of horizontal-confined track lengths and track densities in basal sections and randomly oriented grains (2006) Am. Mineral, 91, pp. 252-260Wagner, G., Van den haute, P., (1992) Fission Track Dating, , Kluwer Academic Publishers, Dordrecht, The Netherlands 285pYoshioka, T., Tsuruta, T., Iwano, H., Danhara, T., Spontaneous fission decay constant of 238U determined by SSNTD method using CR-39 and DAP plates (2005) Nucl. Instrum. Methods Phys. A, 555, pp. 386-39
Boron Thin Films And Cr-39 Detectors In Bnct: A Method To Measure The 10b(n,α)7li Reaction Rate
No full textThe working principle of the Boron Neutron Capture Therapy (BNCT) is the selective delivery of a greater amount of boron to the tumor cells than to the healthy ones, followed by the neutron irradiation that will induce the emission of α-particles and recoil 7Li nuclei through the 10B(n,α)7Li reaction. The objective of this work is to present a setup composed of a boron thin film coupled with CR-39. Alpha and 7Li particle coming from the boron films are used to quantify neutron boron reaction and are detected by CR-39. The nuclei compounding of this detector, H, C and O, will undergo fast neutrons reactions, which will be detected in the CR-39 itself. In this way, the 10B(n,α) 7Li reaction and the contribution of fast neutrons to the flux can be determined at the same time. These measurements are essential for treatment planning as well as for studies of the biodistribution of 10B-carrier drugs and tissue microdosimetry. The boron films were deposited on stainless steel substrates through the sputtering technique and irradiated with thermal neutrons at the reactor IEA-R1 located at IPEN, São Paulo/SP, Brazil. Here we show the first results on the characterization of these thin films and calibration of the proposed setup. © 2012 Elsevier Ltd. All rights reserved.50181186Altieri, S., Bortolussi, S., Bruschi, P., Chiari, P., Fossati, F., Stella, S., Prati, U., Pinelli, T., Neutron autoradiography imaging of selective boron uptake in human metastatic tumours (2008) Appl. Radiat. Isot., 66, pp. 1850-1855Barth, R., Coderre, J.A., Vicente, M.G.H., Blue, T.E., Boron neutron capture therapy of cancer: Current status and future prospects (2005) Clin. Cancer Res., 11, pp. 3987-4002Behrisch, R., (1981) Sputtering by Particle Bombardment I: Physical Sputtering of Single-Element Solids, , Springer Berlin 3540105212Bigazzi, G., Hadler, J.C., Iunes, P.J., Mineral dating by the fission track method: Neutron dosimetry by thin film of natural uranium (1993) Revista de Física Aplicada e Instrumentação, 8, pp. 13-23Bigazzi, G., Hadler, J.C., Iunes, P.J., Mello, T.C.W.P., Navia, L.M.S., Paulo, S.R., Zúñiga, A., Employment of thin thorium films in fission track neutron dosimetry (1995) Braz. J. Phys., pp. 246-251Bigazzi, G., Hadler, J.C., Iunes, P.J., Oddone, M., Paulo, S.R., Zúñiga, A., Absolute thermal neutron fluence determination by thin film of natural uranium (1995) Nucl. Instrum. Meth. Phys. Res., 352 A, pp. 588-591Bigazzi, G., Guedes, S., Hadler, J.C., Iunes, P.J., Oddone, M., Osorio, A.M., Paulo, S.R., Zúñiga, A., Potentialities and practical limitations of an absolute neutron dosimetry using thin films of uranium and thorium applied to the Fission Track Method (1999) Radiat. Meas., 31, pp. 651-656Coderre, J.A., Morris, G.M., The radiation biology of boron neutron capture therapy (1999) Radiat. Res., 151, pp. 1-18Deevband, M.R., Abdolmaleki, P., Kardan, M.R., Khosravi, H.R., Taheri, M., An investigation on the response of PADC detectors to neutrons (2011) Appl. Radiat. Isot., 69, pp. 340-345Durham, J.S., Blue, T.E., Wehring, B.W., Ragheb, M.H., Blue, J.W., Microdosimetry in fast-neutron therapy by automatic readout of CR-39 solid state nuclear track detectors (1989) Nuc. Instr. Meth. Phys. Res., 36 B, pp. 319-331Quantification and reporting of low-dose and other heterogeneous exposures (2011) J. ICRU, 11, pp. 1-77Iunes, P.J., Hadler, J.C., Bigazzi, G., Guedes, S., Zúñiga, A., Paulo, S.R., Tello, S.C.A., Uranium and thorium thin film calibrations by particle track techniques (2004) J. Radioanalytical Nucl. Chem., 262, pp. 461-468Smilgys, B., Guedes, S., Hadler, J.C., Coelho, P.R.P., Alencar, I., Soares, C.J., Salim, L.A., Manufacturing of boron thin films for the measurement of the 10B(n,α)7Li reaction in BNCT (2011) Proc. Sci., , XXXIV BWN
Comparison Between Thorium And Uranium Fission Track Diameters In Glass
No full textComparisons between diameters of uranium and thorium neutron induced fission tracks in glass made possible to test indirectly the hypothesis that observation efficiency of spontaneous 238U and induced 235U fission tracks may be considered the same. The sources of fission fragments were uranium and thorium thin films irradiated with neutrons with and without Cd-cover. After irradiation, the glasses were etched for 50 s by HF 24% at 15 {ring operator} C followed by another etching for 30 s in same conditions. Diameters were measured after each chemical etching. Only tracks presenting a ratio between the longer and shorter diameters lesser than 1.1 have been analyzed. The results indicates the hypothesis is valid. © 2008 Elsevier Ltd. All rights reserved.43SUPPL.1S329S333Bigazzi, G., Hadler, J.C., Iunes, P.J., Osório, A.M., Fission track DS / DI measurement in artificial glass at conditions free from fading and radiation (1991) Nucl. Instrum. Methods B, 53, pp. 67-70Iunes, P.J., Hadler, J.C., Bigazzi, G., Tello, C.A., Guedes, S.O., Paulo, S.R., Durango apatite fission-track dating using length-based age corrections and neutron fluence measurements by thorium thin films and natural U-doped glasses calibrated through natural uranium thin films (2002) Chem. Geol., 187, pp. 201-211Tagami, T., Nishimura, S., Neutron dosimetry and fission-track age calibration: insights from intercalibration of uranium and thorium glass dosimeters (1992) Chem. Geol., 102, pp. 277-296Wagner, G.A., Van den haute, P., (1992) Fission-track dating, , Kluwer Academics Publisher, LondonWahl, J.S., Energy distributions of fragments from fission of 235U, 238U and 239Pu by fast neutrons (1954) Phys. Rev., 95, pp. 126-13
Indoor Radon And Radon Progeny Survey At Campinas-brazil Using Cr-39: Final Results
No full textIn a survey performed at Campinas-SP, Brazil, the CR-39 detector was used as an alpha-spectrometer taking into account the size and the gray level of round tracks measured under an automatic optical microscopy system. The exposures were carried out in the same room of 70 dwellings during two successive periods of six months: the first one from November 1996 to May 1997 (summer exposure) and the second one from May 1997 to December 1997 (winter exposure). The results of the assessment of radon and radon progeny (RP) joint activity in the air neighboring the detector and the plated-out RP activity on the material surfaces are given. © 2008 Elsevier Ltd. All rights reserved.43SUPPL.1S440S444Abu-Jarad, F., Radon measurements inside houses using nuclear track etch detectors (1989) Proceedings of the International Workshop on Radon Monitoring in Radioprotection, Environmental Radioactivity and Earth Sciences, ICTP, Trieste, Italy, April 3-14, pp. 445-456. , World Scientific Publishing Co. Pte. Ltd., SingaporeAmgarou, K., Font, L., Baixeras, C., A novel approach for long-term determination of indoor 222Rn progeny equilibrium factor using nuclear track detectors (2003) Nucl. Instrum. Meth. A, 506, pp. 186-198Durrani, S.A., Ilic, R., (1997) Radon Measurements by Etched Track Detectors: Applications in Radiation Protection, Earth Sciences and the Environment, , World Scientific Publishing Co., LondonGuedes, S., Hadler, J.C., Iunes, P.J., Navia, L.M.S., Neman, R.S., Paulo, S.R., Rodrigues, V.C., Zúñiga, A., Indoor radon daughters survey at Campinas-Brazil using CR-39: first results (1999) Radiat. Meas., 31, pp. 287-290Hadler, J.C., Paulo, S.R., Indoor radon daughters contamination monitoring: the absolute efficiency of CR-39 taking into account the plate-out effect and environmental conditions (1994) Radiat. Protect. Dosim., 51 (4), pp. 283-296Lung cancer risk from indoor exposures to radon daughters (1987) Ann. ICRP, 17, pp. 1-60. , ICRP Publication 50Leung, S.Y.Y., Nikezic, D., Yu, K.N., Passive monitoring of the equilibrium factor inside a radon exposure chamber using bare LR115 SSNTDs (2006) Nucl. Instrum. Meth. A, 564, pp. 319-323Paulo, S.R., Neman, R., Hadler, J.C., Iunes, P.J., Guedes, S., Balan, A.M.O.A., Tello, C.A., Radon surveys in Brazil using CR-39 (2005) Radiat. Meas., 39 (6), pp. 657-660Planinic, J., Radolic, V., Faj, Z., Suveljak, B., Radon equilibrium factor and aerosols (1997) Nucl. Instrum. Meth. A, 396, pp. 414-417Soroka, Y., Molchanov, A., Radiation and radon survey of Akchatau (Kazakhstan) and experience with radon remedial measures (1998) Radiat. Protect. Dosim., 78, pp. 231-236WHO, 1988. Man-made mineral fibres and radon. In: IARC Monographs on the Evaluation of Carciogenic Risks to Humans, vol. 43, pp. 173-25
Extrapolation Of Zircon Fission-track Annealing Models
No full textOne of the purposes of this study is to give further constraints on the temperature range of the zircon partial annealing zone over a geological time scale using data from borehole zircon samples, which have experienced stable temperatures for ∼1 Ma. In this way, the extrapolation problem is explicitly addressed by fitting the zircon annealing models with geological timescale data. Several empirical model formulations have been proposed to perform these calibrations and have been compared in this work. The basic form proposed for annealing models is the Arrhenius-type model. There are other annealing models, that are based on the same general formulation. These empirical model equations have been preferred due to the great number of phenomena from track formation to chemical etching that are not well understood. However, there are two other models, which try to establish a direct correlation between their parameters and the related phenomena. To compare the response of the different annealing models, thermal indexes, such as closure temperature, total annealing temperature and the partial annealing zone, have been calculated and compared with field evidence. After comparing the different models, it was concluded that the fanning curvilinear models yield the best agreement between predicted index temperatures and field evidence. © 2012 Elsevier Ltd. All rights reserved.50192196Carlson, W.D., Mechanisms and kinetics of apatite fission-track annealing (1990) Am. Mineral, 75, pp. 1120-1139Crowley, K.D., Cameron, M., Shaefer, R.L., Experimental studies of annealing of etched fission tracks in fluor apatite (1991) Geochim. Cosmochim. Acta, 55, pp. 1449-1465Dodson, M.H., Closure temperature in cool geochronological and petrological systems (1973) Contrib. Mineral Petrol., 40, pp. 259-274Duddy, I.R., Green, P.F., Laslett, G.M., Thermal annealing of fission tracks in apatite. 3. Variable temperature behaviour (1988) Chem. Geol., 73, pp. 25-38Guedes, S., Hadler, J.C., Iunes, P.J., Tello, C.A., Kinetic model for the relationship between confined fission-track length shortening and fission track age reduction in minerals (2004) Nucl. Instrum. Methods B, 217, pp. 627-636Guedes, S., Hadler, J.C., Iunes, P.J., Oliveira, K.M.G., Moreira, P.A.F.P., Tello, C.A., Kinetic model for the annealing of fission tracks in zircon (2005) Radiat. Meas., 40, pp. 517-521Guedes, S., Hadler, J.C., Oliveira, K.M.G., Moreira, P.A.F.P., Iunes, P.J., Tello, C.A., Kinetic model for the annealing of fission tracks in minerals and its application to apatite (2006) Radiat. Meas., 41, pp. 392-398Guedes, S., Moreira, P.A.F.P., Devanathan, R., Weber, W.J., Hadler, J.C., Improved Fission-track Annealing Model Based on Reevaluation of Annealing Data, , submittedHasebe, N., Mori, S., Tagami, T., Matsui, R., Geological partial annealing zone of zircon fission-track system: Additional constraint from the deep drilling MITI-Nischikubi and MITIMishima (2003) Chem. Geol., 199, pp. 45-52Laslett, G.M., Green, P.F., Duddy, I.R., Gleadow, J.W.A., Thermal annealing of fission tracks in apatite 2. A quantitative analysis (1987) Chem. Geol. Isot. Geosci. Sect., 65, pp. 1-13Laslett, G.M., Galbraith, R.F., Statistical modeling of thermal annealing of fission tracks in apatite (1996) Geochim. Cosmochim. Acta, 60, pp. 5117-5131Murakami, M., Yamada, R., Tagami, T., Short-term annealing characteristics of spontaneous fission tracks in zircon: A qualitative description (2006) Chem. Geol. Isot. Geosc. Sect., 227, pp. 214-222Palenik, C.S., Nasdala, L., Ewing, R.C., Radiation damage in zircon (2003) Am. Mineral, 88, pp. 770-781Rahn, M.K., Brandon, M.T., Batt, G.E., Garver, J.I., A zero-damage model for fission-track annealing in zircon (2004) Am. Mineral, 89, pp. 473-484Tagami, T., Ito, H., Nishimura, S., Thermal annealing characteristics of fission tracks in zircon (1990) Chem. Geol. Isot. Geosci. Sect., 80, pp. 159-169Tagami, T., Galbraith, R.F., Yamada, R., Laslett, G.M., (1998) Revised Annealing Kinetics of Fission Tracks in Zircon and Geological Implications. Advances in Fission-Track Geochronology, , Kluwer Academic Publishing The Netherlands pp. 99-112Yamada, R., Tagami, T., Nishimura, S., Ito, H., Annealing kinetics of fission tracks in zircon: An experimental study (1995) Chem. Geol. Isot. Geosci. Sect., 122, pp. 249-258Yamada, R., Murakami, M., Tagami, T., Statistical modeling of annealing kinetics of fission tracks in zirconReassessment of laboratory experiments (2007) Chem. Geol., 236, pp. 75-9
Cr-39 Alpha Particle Spectrometry For The Separation Of The Radon Decay Product 214po From The Thoron Decay Product 212po
No full textIn this work, it is presented an experimental assembly based on electric capture of radionuclides in order to discriminate the alpha activity of 214Po (radon decay product) from 212Po (thoron decay product) one. The alpha activity was registered with CR-39 analyzing etch pit diameters and optical density. This discrimination may allow for the estimation of the relative contribution of the alpha activity due to thoron decay products compared to the total activity due to radon decay products. © 2010 Elsevier Ltd. All rights reserved.457823826Abreu, S.F., Recursos Minerais do Brasil (1962) MIC - Instituto Nacional de Tecnologia, 2, p. 633. , Rio de JaneiroFromm, M., Membrey, F., Chambaudet, A., Saouli, R., Proton and alpha track profiles in CR-39 during etching and their implications on track etching models (1991) Nucl. Tracks Radiat. Meas., 19, pp. 163-168Fromm, M., Membrey, F., Rahamany, A.E., Chambaudet, A., Principle of light-ions micromapping and dosimetry using a CR-39 polymeric detector - Modelized and experimental uncertainties (1993) Nucl. Tracks Radiat. Meas., 21, pp. 357-365Hadler, J.C., Iunes, P.J., Osorio, A.M., Paulo, S.R., Relationship between track size and energy for alpha particles in CR-39 (1991) Nucl. Tracks Radiat. Meas., 19, pp. 313-317Hadler, J.C., Paulo, S.R., Indoor radon daughter contamination monitoring - The absolute efficiency of CR-39 taking into account the plate-out effect and environmental-conditions (1994) Radiat. Prot. Dosimetry, 51, pp. 283-296Lederer, C.M., Shirley, V.M., (1978) Table of Isotopes, Seventh, p. 1523. , ed. Wiley-interscience, New York, USA(1983) Ministério Das Minas E Energia, Secretaria Geral, Levantamento de Recursos Naturais, 32, p. 261. , Projeto RadamBrasilSantos, N.F., Hadler, J.C., Iunes, P.J., Guedes, S., Paulo, S.R., CR-39 detectors calibration using a beehive collimator (2005) Radiat. Meas., 39, pp. 661-664Somogyi, G., Hunyadi, I., Hafez, A.F., Espinosa, G., A new possibility for highresolution spectroscopy of nuclear-particles entering CR-39 at selected dip angles (1984) Nucl. Tracks Radiat. Meas., 8, pp. 163-166Ziegler, J.F., (2006) SRIM 2006, 2. , http://www.srim.or
Improved Zircon Fission-track Annealing Model Based On Reevaluation Of Annealing Data
No full textThe thermal recovery (annealing) of mineral structure modified by the passage of fission fragments has long been studied by the etching technique. In minerals like apatite and zircon, the annealing kinetics are fairly well constrained from the hour to the million-year timescale and have been described by empirical and semi-empirical equations. On the other hand, laboratory experiments, in which ion beams interact with minerals and synthetic ceramics, have shown that there is a threshold temperature beyond which thermal recovery impedes ion-induced amorphization. In this work, it is assumed that this behavior can be extended to the annealing of fission tracks in minerals. It is proposed that there is a threshold temperature, T0, beyond which fission tracks are erased within a time t0, which is independent of the current state of lattice deformation. This implies that iso-annealing curves should converge to a fanning point in the Arrhenius pseudo-space (ln t vs. 1/T). Based on the proposed hypothesis, and laboratory and geological data, annealing equations are reevaluated. The geological timescale estimations of a model arising from this study are discussed through the calculation of partial annealing zone and closure temperature, and comparison with geological sample constraints found in literature. It is shown that the predictions given by this model are closer to field data on closure temperature and partial annealing zone than predictions given by previous models. © 2012 Springer-Verlag Berlin Heidelberg.40293106Afra, B., Lang, M., Rodriguez, M.D., Zhang, J., Giulian, R., Kirby, N., Ewing, R.C., Kluth, P., Annealing kinetics of latent particle tracks in Durango apatite (2011) Phys Rev B, 83, p. 064116Bai, X.M., Voter, A.F., Hoagland, R.G., Nastasi, M., Uberuaga, B.P., Efficient annealing of radiation damage near grain boundaries via interstitial emission (2010) Science, 237, pp. 1631-1634Barbarand, J., Carter, A., Wood, I., Huford, T., Compositional and structural control of fission-track annealing in apatite (2003) Chem Geol, 198, pp. 107-137Caldeira, A.O., Leggett, A.J., Influence of dissipation on quantum tunneling in macroscopic systems (1982) Phys Rev Lett, 46, pp. 211-214Caldeira, A.O., Leggett, A.J., Quantum tunnelling in a dissipative system (1983) Ann Phys, 149, pp. 374-456Carlson, W.D., Mechanisms and kinetics of apatite fission-track annealing (1990) Am Miner, 75, pp. 1120-1139Carlson, W.D., Mechanisms and kinetics of apatite fission-track annealing-reply to Kevin D. Crowley (1993) Am Miner, 78, pp. 213-215Carlson, W.D., Mechanisms and kinetics of apatite fission-track annealing-Reply to Green et al (1993) Am Miner, 78, pp. 446-449Carlson, W.D., Donelick, R.A., Ketcham, R.A., Variability of apatite fission-track annealing kinetics: I. Experimental results (1999) Am Miner, 84, pp. 1213-1223Crowley, K.D., Mechanisms and kinetics of apatite fission-track annealing-Discussion (1993) Am Miner, 78, pp. 210-212Crowley, K.D., Cameron, M., Schaefer, R.L., Experimental studies of annealing of etched fission tracks in fluorapatite (1991) Geoch Cosmoch Ac, 55, pp. 1449-1465Curvo, E.A., Hadler, J.C., Iunes, P.J., Guedes, S., Tello, C.A.S., Paulo, S.R., Hackspacher, P.C., Moreira, P.A.F.P., On epidote fission track dating (2005) Radiat Meas, 39 (641), p. 645Dodson, M.H., Cooling temperature in cooling geochronological and petrological systems (1973) Contrib Miner Petr, 40, pp. 259-274Duddy, I.R., Green, P.F., Laslett, G.M., Thermal annealing of fission tracks in apatite. 3. Variable temperature behavior (1988) Chem Geol, 73, pp. 25-38Ellsworth, S., Navrotsky, A., Ewing, R.C., Energetics of radiation damage in natural zircon (ZrSiO4) (1994) Phys Chem Miner, 21, pp. 140-149Emsley, J., (1991) The Elements, , Oxford: Claredon PressEwing, R.C., Meldrum, A., Wang, L., Weber, W.J., Corrales, L.R., Radiation effects in zircon (2003) Rev Miner Geochem, 53, pp. 387-425Gaines, R.V., Skinner, H.C.W., Foord, E.E., Mason, B., Rosenzweig, A., (1997) Dana's New Mineralogy, , New York: WileyGalbraith, R.F., Laslett, G.M., Statistical modelling of thermal annealing of fission tracks in zircon (1997) Chem Geol, 140, pp. 123-135Gold, R., Roberts, J.H., Ruddy, F.H., Advances in SSTR techniques for dosimetry and radiation damage measurements (1979) In: Third international ASTM-EURATOM symposium on reactor dosimetry, pp. 1172-1187. , Ispra (Varese) Italy, 1-5 Oct 1979 (ed. Röttger H.) Dosimetry methods for fuels, cladding and structural materials, EUR-6813, Joint Research Centre, PetteuGold, R., Roberts, J.H., Ruddy, F.H., Annealing phenomena in solid state track recorders (1981) Nucl Tracks, 5, pp. 253-264Green, P.F., Duddy, I.R., Gleadow, A.J.W., Tingate, P.R., Laslett, G.M., Thermal annealing of fission tracks in apatite 1. Qualitative description (1986) Chem Geol, 59, pp. 237-253Green, P.F., Laslett, G.M., Duddy, I.R., Mechanisms and kinetics of apatite fission-track annealing-Discussion (1993) Am Miner, 78, pp. 441-445Guedes, S., Hadler, J.C., Iunes, P.J., Tello, C.A.S., Kinetic model for the relationship between confined fission-track length shortening and fission-track age reduction in minerals (2004) Nucl Instrum Meth B, 217, pp. 627-636Guedes, S., Hadler, J.C., Iunes, P.J., Oliveira, K.M.G., Moreira, P.A.F.P., Tellos, C.A.S., Kinetic model for the annealing of fission tracks in zircon (2005) Radiat Meas, 40, pp. 517-521Guedes, S., Hadler, J.C., Oliveira, K.M.G., Moreira, P.A.F.P., Iunes, P.J., Tellos, C.A.S., Kinetic model for the annealing of fission tracks in minerals and its application to apatite (2006) Radiat Meas, 41, pp. 392-398Guedes, S., Curvo, E.A.C., Tello, C.A.S., Hadler, J.C., Iunes, P.J., Paulo, S.R., Palissari, R., On the annealing of fission tracks in randomly oriented grains of apatite (2007) Nucl Instrum Meth B, 256, pp. 683-692Guedes, S., Jonckheere, R., Moreira, P.A.F.P., Hielscher, R., On the calibration of fission-track annealing models (2008) Chem Geol, 248, pp. 1-13Hasebe, N., Tagami, T., Nishimura, S., Towards zircon fission-track thermochronology: reference framework for confined length measurements (1994) Chem Geol, 112, pp. 169-178Hasebe, N., Mori, S., Tagami, T., Matsui, R., Geological partial annealing zone of zircon fission-track system: additional constrains from the deep drilling MITI-Nishikubiki and MITI-Mishima (2003) Chem Geol, 199, pp. 45-52Jonckheere, R., On the densities of etchable fission tracks in a mineral and co-irradiated external detector with reference to fission-track dating of minerals (2003) Chem Geol, 200, pp. 41-58Jonckheere, R., On methodical problems in estimating geological temperature and time from measurements of fission tracks in apatite (2003) Radiat Meas, 36, pp. 43-55Jonckheere, R., Wagner, G.A., On the thermal stability of fossil and neutron-induced fission-tracks in natural titanite (2000) Nucl Instrum B, 16, pp. 78-87Ketcham, R.A., Donelick, R.A., Carlson, W.D., Variability of apatite fission-track annealing kinetics: III. Extrapolation to geological time scales (1999) Am Miner, 84, pp. 1235-1255Ketcham, R.A., Carter, A., Donelick, R.A., Barbarand, J., Hurford, A.J., Improved modeling of fission-track annealing in apatite (2007) Am Miner, 92, pp. 799-810Koch, W., Grossmann, F., Tannor, D.J., Trajectory based non-markovian dissipative tunneling (2010) Phys Rev Lett, 105, p. 230405Lang, M., Lian, J., Zhang, F., Hendriks, B.W.H., Trautmann, C., Neumann, R., Ewing, R.C., Fission tracks simulated by swift heavy ions at crustal pressures and temperatures (2008) Earth Planet Sci Lett, 274, pp. 355-358Laslett, G.M., Galbraith, R.F., Statistical modelling of thermal annealing of fission tracks in apatite (1996) Geoch Cosmoch Ac, 60, pp. 5117-5131Laslett, G.M., Green, P.F., Duddy, I.R., Gleadow, A.J.W., Thermal annealing of fission tracks in apatite. 2. A quantitative analysis (1987) Chem Geol, 65, pp. 1-13Levitan, J., Suchanecki, Z., Effect of noise on the tunneling through a potential barrier (1994) Phys Rev A, 50, pp. 2761-2763Li, W., Wang, L., Lang, M., Trautmann, C., Ewing, R.C., Thermal annealing mechanisms of latent fission tracks: apatite vs. zircon (2011) Earth Planet Sci Lett, 302, pp. 227-235Li, W., Lang, M., Gleadow, A.J.W., Zdorovets, M.V., Ewing, R.C., Thermal annealing of unetched fission tracks in apatite (2012) Earth Planet Sci Lett, 321, pp. 121-127Lian, J., Wang, M., Sun, K., Ewing, R.C., In situ TEM of radiation effects in complex ceramics (2009) Microsci Res Tech, 72, pp. 165-181Meldrum, A., Wang, L.M., Ewing, R.C., Ion beam induced amorphization of monazite (1996) Nucl Instrum Meth B, 116, pp. 220-224Meldrum, A., Zinkle, S.J., Boatner, L.A., Ewing, R.C., Heavy-ion irradiation effects in the ABO4 orthosilicates: recrystallization decomposition, amorphization, and recrystallization (1999) Phys Rev B, 59, pp. 3981-3992Moreira, P.A., Devanathan, R., Weber, W.J., Atomistic simulation of track formation by energetic recoils in zircon (2010) J Phys Condens Mat, 22, p. 395008Murakami, M., Yamada, R., Tagami, T., Short-term annealing characteristics of spontaneous fission tracks in zircon: a qualitative description (2006) Chem Geol, 227, pp. 214-222Nasdala, L., Hanchar, J., Wirth, R., Blanc, P., Kennedy, A., Seydoux-Guillaume, A., Annealing radiation damage and the recovery of cathodoluminescence (2002) Chem Geol, 191, pp. 121-140Paul, T.A., Transmission electron microscopy investigation of unetched in fission tracks in fluorapatite-physical process of annealing (1993) Nucl Tracks Radiat Meas, 21, pp. 507-511Paul, T.A., Fitzgerald, P.G., Transmission electron microscopic investigation of fission tracks in fluorapatite (1992) Am Miner, 77, pp. 336-344Rahn, M.K., Brandon, M.T., Batt, G.E., Garver, J.I., A zero-damage model for fission-track annealing in zircon (2004) Am Miner, 89, pp. 473-484Ravenhurst, C.E., Roden-Tice, M.K., Miller, D.S., Thermal annealing of fission tracks in fluorapatite, chlorapatite, manganoanapatite, and Durango apatite: experimental results (2003) Can J Earth Sci, 40, pp. 995-1007Roberts, J.H., Gold, R., Ruddy, F.H., Thermal annealing studies in muscovite and quartz (1980) In: Tenth international conference on solid state nuclear track detectors, pp. 177-183. , Lyons, France, 2-7 July 1979, (eds François H. et al.), Prgamon Press, OxfordSchiwietz, G., Czerski, K., Roth, M., Staufenbiel, F., Grande, P.L., Femtosecond dynamics-snapshots of the early ion-track evolution (2004) Nucl Instr Meth Phys Res B, 225, pp. 4-26Smith, W., Forester, T.R., DL_POLY_2.0: a general-purpose parallel molecular dynamics simulation package (1996) J Mol Graph, 14, pp. 136-141Szenes, G., Amorphous tracks in insulators induced by monoatomic and cluster ions (1999) Phys Rev B, 60, pp. 3140-3147Tagami, T., Galbraith, R.F., Yamada, R., Laslett, G.M., Revised annealing kinetics of fission tracks in zircon and geological implications (1998) Advances in Fission-Track Geochronology, pp. 99-112. , P. 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CorteDe (Eds.), London: Academic PublishersTello, C.A., Palissari, R., Hadler, J.C., Iunes, P.J., Guedes, S., Curvo, E.A.C., Paulo, S.R., Annealing experiments on induced fission tracks in apatite: measurements of horizontal-confined track lengths and track densities in basal sections and randomly oriented grains (2006) Am Miner, 91, pp. 252-260Utsunomiya, S., Wang, L.M., Ewing, R.C., Ion irradiation effects in natural garnets: comparison with zircon (2002) Nucl Instr Meth Phys Res B, 191, pp. 600-605Utsunomiya, S., Wang, L.M., Yudintsev, S., Ewing, R.C., Ion irradiation-induced amorphization and nano-crystal formation in garnets (2002) J Nucl Mater, 303, pp. 177-187Utsunomiya, S., Yudintsev, S., Ewing, R.C., Radiation effects in ferrate garnet (2005) J Nucl Mat, 336, pp. 251-260Virk, H.S., Single activation-energy model of radiation-damage in solid-state nuclear track detectors (1995) Radiat Eff Defect, 133, pp. 87-95Wagner, G.A., van Den Haute, P., (1992) Fission-Track Dating. 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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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