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Sample records for neutrons na regiao

  1. Autopercepcao da saude bucal entre adultos na regiao Nordeste do Brasil

    Directory of Open Access Journals (Sweden)

    Edivania Barbosa do Vale

    2013-12-01

    Full Text Available OBJETIVO: Identificar a autopercepção da saúde bucal por adultos e variáveis associadas. MÉTODOS: Estudo realizado com os dados da Pesquisa Nacional de Saúde Bucal SBBrasil 2010 relativos a 2.456 adultos de 35 a 44 anos da região Nordeste. A variável dependente foi a autopercepção da saúde bucal. As variáveis independentes foram agrupadas em: demográficas, predisposição/facilitação, condição de saúde bucal e relacionadas à autopercepção da necessidade de tratamento. O teste de Rao e Scott foi utilizado para avaliar a associação entre essas variáveis. O efeito das variáveis independentes sobre o desfecho foi avaliado pelo modelo de regressão logística multinominal segundo modelo hierarquizado, em duas etapas: análise simples e análise múltipla hierarquizada. RESULTADOS: A autopercepção positiva da saúde bucal foi observada em 37% dos participantes. No modelo final, as características diretamente associadas a essa autopercepção foram: ser branco, ter renda familiar superior a R$ 500,00, possuir número de bens acima da mediana, ter maior número de dentes hígidos, não apresentar sangramento, não necessitar de prótese, Oral Impacts on Daily Performances = 0, não necessitar de tratamento e ter ido ao dentista há menos de três anos. CONCLUSÕES: Os resultados mostram que a autopercepção da saúde bucal dos adultos residentes no Nordeste brasileiro está diretamente associada a uma estrutura multidimensional de fatores. As baixas condições econômicas associadas às condições clínicas deficientes dessa população causam grande impacto na sua autopercepção da saúde bucal.

  2. Multielementar determination by neutron activation in sediment samples from Tartarugalzinho region, Amapa State, Brazil; Determinacao multielementar em amostras de sedimentos da regiao do Tartarugalzinho, Amapa, por ativacao neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Neri, Maria C.; Favaro, Debora I.T.; Vasconcellos, Marina B.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Oliveira, Sonia M.B. de; Melfi, Adolfo J. [Sao Paulo Univ., SP (Brazil). Inst. de Geociencias; Fostier, Anne H. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Quimica Analitica; Guimaraes, Jean R.D. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Biofisica; Forti, Maria C. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil)

    1999-11-01

    In the present work, sediment samples collected in the Tartarugalzinho region, State of Amapa, were analyzed by instrumental neutron activation analysis. The concentration of the elements As, Ba, Br, Co, Cr, Cs, Fe, Na, Rb, Sc, Se, Ta, Th, U, Zn and Zr and the rare earth elements Ce, Eu, La, Lu, Nd, Sm, Tb and Yb could be determined. Analysis of the reference materials Buffalo River Sediment (NIST SRM 2704) and Soil 7 (IAEA) showed the accuracy and precision of the method. (author) 4 refs., 1 fig., 7 tabs.

  3. Consumo de alcool e risco para doenca coronariana na regiao metropolitana de Sao Paulo: uma analise do Projeto GENACIS

    Directory of Open Access Journals (Sweden)

    Maria Cristina Pereira Lima

    2013-03-01

    Full Text Available OBJETIVOS: Examinar a associação entre consumo de álcool e risco para doença coronariana em amostra populacional. MÉTODOS: Estudo transversal, de base populacional, conduzido de janeiro/2006 a junho/2007, na região metropolitana de São Paulo, como parte do estudo internacional (Gender, Alcohol, and Culture: an International Study. Os sujeitos (1.501, sendo 609 homens e 892 mulheres eram residentes da região metropolitana de São Paulo, tinham 30 anos ou mais de idade e foram selecionados aleatoriamente, a partir de amostragem complexa por conglomerados. Todos os indivíduos consentiram em participar da pesquisa. A variável dependente foi risco cardíaco avaliado através do WHO Rose Angina Questionnaire. A análise multivariada consistiu em regressão logística, tendo sido realizado ajuste para uso de tabaco e índice de massa corpórea. RESULTADOS: A taxa de resposta foi 75%. Ser mulher, ter mais idade, ser negro, fumante e ter um índice de massa corpórea elevado, foram associados a maior risco para doença coronariana. Indivíduos que nunca beberam na vida (OR = 2,22 e ex-bebedores (OR = 2,42 tiveram maior risco de doença cardíaca do que aqueles que informaram beber até 19 g de álcool por dia, sem episódios de beber excessivo. Entre os que tiveram episódios de embriaguês observou-se uma tendência a maior risco (OR = 3,95, p = 0,09. CONCLUSÕES: Nossos achados sugerem um menor risco para doença coronariana entre os bebedores moderados. Destaca-se que os estudos que avaliam o impacto do álcool sobre doença cardíaca precisam identificar o padrão de uso de álcool dos sujeitos, visto que este aspecto pode modificar o risco. Políticas públicas são necessárias para reduzir o uso nocivo de álcool e a morbidade a ele relacionada no país.

  4. Study of Neutron-Unbound States with MoNA

    Science.gov (United States)

    Kuchera, A. N.; Spyrou, A.; Smith, J. K.; Baumann, T.; Christian, G.; De Young, P. A.; Finck, J. E.; Frank, N.; Jones, M. D.; Kohley, Z.; Mosby, S.; Peters, W. A.; Thoennessen, M.

    2015-06-01

    The Modular Neutron Array (MoNA) in conjunction with the large-gap Sweeper magnet at the NSCL is an effective setup to explore neutron-unbound states and has been operating for ten years. Neutron-unbound nuclei beyond the drip-line as well as neutron unbound excited states of bound nuclei have been populated primarily using proton removal reactions. A recent example, the search for 3n emission of the decay of 15Be to1 12Be, is discussed.

  5. Neutron detection by large NaI crystal

    Energy Technology Data Exchange (ETDEWEB)

    Lavagno, A., E-mail: andrea.lavagno@polito.it [Department of Applied Science and Technology, Politecnico di Torino (Italy); INFN Sezione di Torino (Italy); Gervino, G. [Dipartimento di Fisica, Università di Torino (Italy); INFN Sezione di Torino (Italy)

    2016-07-11

    In present days new neutron detection methods are under developed due to the global shortage of {sup 3}He and the toxicity of BF{sub 3}. Neutrons can be indirectly detected by high-energy photons. The performance of a cylindrical NaI crystal, 4 in. diameter and 8 in. length as an indirect neutron detector has been investigated. Measurements were performed with {sup 252}Cf source with bare and shielded NaI detector. With a proper converter and moderator structure for the NaI detector, the detection efficiencies and the minimum detectable activities are improved, making the method very interesting for security applications. The indirect detection of neutrons by photons has several advantages. First, this method can in principle be suited by any gamma spectrometer with only slight modifications that do not compromise with its gamma spectrometry measurements. Second, fission neutron sources and neutron generators can be discriminated thanks to their different gamma energy spectra, a discrimination easily done by a NaI spectrometer.

  6. Neutron activation analysis of soil samples collected at different points of the metropolitan region of Sao Paulo, Brazil; Analise por ativacao com neutrons de amostras de solo coletadas em diferentes pontos da regiao metropolitana de Sao Paulo, SP

    Energy Technology Data Exchange (ETDEWEB)

    Bunevich, Rodrigo Brandao [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias]. E-mail: rbunevich@gmail.com; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: mitiko@ipen.br

    2007-07-01

    This article analyses samples from the soil of Sao Paulo metropolitan region (SPMR) aiming posterior study on the influence of his elementary composition in the elements accumulated by the lichen. The article analyses soils samples from various points at SPMR) and at the clean region of Parque Intervales, Mata Atlantica, SP by using the neutron activation analysis. The concentration of the elements As, Br, Co, Fe, Hf, K, Nd, Rb, Sb, Th, U, Zn and rare earths were determined, and comparative studies were also performed between the concentrations obtained for the samples collected at different sampling points. The samples collected at IPEN and Congonhas presented high La and Nd concentrations when compared with the other ones. The high Ce, Th and U concentrations were obtained for the IPEN soil samples. Besides, the As and Br presented the highest values at the Santo Andre, Capuava and Cerqueira Cesar. The clean region samples of Parque Intervales presented lower concentrations related to most of collected points at the SPMR, excepted the elements Sc and Rb. The quality control were evaluated by analysing the reference certificated materials Soil 7 and Buffalo River Sediment. (author)

  7. Análise das alteraçoes na matéria orgânica do solo causadas pelo reflorestamento de Pinus elliotti na regiao da Lapa - PR

    OpenAIRE

    Kahil, Amalia Lia Endler

    2013-01-01

    O presente trabalho foi realizado no município da Lapa-PR em solo Podzólico-Vermelho Amarelo Álico, em uma área experimental, composta por duas condições de vegetação: Campo nativo e reflorestamento com Pinus elliottii com 17 anos de idade. Foram avaliados os efeitos causados pelo florestamento com Pinus elliottii na matéria orgânica do solo, O estudo concentrou-se na análise da matéria orgânica do solo através de seu fracionamento, pelo método de DABIN¹4 nas diferentes profundidades do solo ...

  8. Neutron Scattering in MoNA detector bars for Comparison with Simulation

    Science.gov (United States)

    Wantz, A.; Boone, J. E.; Rogers, W. F.; Frank, N.; Kuchera, A. N.; Mosby, S.; Thoennessen, M.; MoNA Collaboration

    2017-09-01

    In order to test the effectiveness and accuracy of Monte Carlo simulation (GEANT4 with Menate_R), used by the MoNA collaboration for interpreting neutron-scattering data from the MoNA (Modular Neutron Array) and LISA (Large multi-Institutional Scintillator Arrays at NSCL, MSU, an experiment was conducted at Los Alamos LANSCE center in which 16 MoNA detector bars were exposed to a well characterized neutron beam. Each MoNA bar consists of BC408 organic scintillator measuring 200×10×10 cm3 with PMTs attached to each end. In order to properly characterize important neutron scattering signatures over a wide range of incoming neutron energy, such as scattering angle, mean distance between scatters, multiplicity, and dark-scatter, it is important that background be fully understood and corrected for. Background sources include neutrons scattered from the collimator on entrance to the room, decay of neutron-activation within the bars, neutrons scattering in the room, and cosmic muons. Several methods for accounting for and removing background contributions to data were developed so that data can be compared directly with simulation (which does not contain these background features). Results, including scattering data comparisons with simulation will be presented. Work supported by NSF Grant PHY-1744043.

  9. RETRACTED: Neutron detection by large NaI crystal

    Science.gov (United States)

    Lavagno, A.; Gervino, G.

    2016-07-01

    This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor. The article includes many textual similarities with a work that had already appeared in Nuclear Instruments and Methods in Physics Research A, Volume 697, January 2013, p. 59-63 (10.1016/j.nima.2012.09.010), as well as the Master thesis Neutron detection with high-energy photons using NaI portal monitor, Aalto University, 2012 (https://aaltodoc.aalto.fi/bitstream/handle/123456789/5206/master_holm_philip_2012.pdf?isAllowed=y&sequence=1). One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

  10. Determination of Hg and other elements in fish and plant samples from Amazonic region, by neutron activation analysis; Determinacao de Hg e outros elementos de interesse em amostras de peixes e plantas da regiao amazonica, por analise por ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Favaro, Debora I.T.; Vasconcellos, Marina B.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Supervisao de Radioquimica; Fostier, Anne Helene [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Quimica Analitica

    1996-07-01

    In the present work the region of Serra do Navio, Amapa State, was chosen to asses the Hg contamination due to gold mining activities. As part of monitoring of this region, fishes and plants were collected and analysed by instrumental neutron activation (INAA). Through this method it was possible to determine the concentration of the elements: As, Ca, Cr, Co, Fe, Hg, Rb, Sb, Se and Zn in fishes and Ca, Co, Cr, Fe, Hg, La, Na, Rb, Sb, Sc, Se and Zn in plants. Mercury concentrations found in fishes ranged from 0.64 to 1.11 {mu}/g and from 0.83 to 0.15 {mu}g/g in plants. These results were compared with those obtained by the atomic absorption technique and they agreed well. The accuracy and precision of the INAA method were checked by means of analyses of reference materials. (author)

  11. Photofission of {sup NAT} Pt by monochromatic and polarized photons in the quasi-deuteron region; Fotofissao da {sup NAT} Pt por fotons monocromaticos e polarizados na regiao do quase-deuteron

    Energy Technology Data Exchange (ETDEWEB)

    Paiva, Eduardo de

    1992-01-01

    The measurement of the Nat Pt photofission yield at 69 MeV of effective average energy of the incident photon is made using a polarized and monochromatic photon beam from the LADON system of the National Laboratory of Frascati, Italy, produced by inverse Compton scattering of laser light by high energy electrons of the ADONE Accelerator and using as fission track solid detector the Makrofol, being the developing made by usual procedure. The experimental value of the nuclear fissionability is compared to a theoretical value obtained following a model at two stages: in the first, the photon energy is absorbed by a neutron-proton pair inducing to the nucleus excitation, and in the second the nucleus de-excites due to the competition between nucleon evaporation and fission. The effect of fast nucleon emission during the first stage and the successive evaporation of neutrons in the second stage are considered. 40 refs, 12 figs, 9 tabs.

  12. Utilization of bromeliad Tillandsia Usneoides L. in biomonitoring of air pollution in the metropolitan region of Sao Paulo - SP, Brazil; Utilizacao da bromelia Tillandsia Usneoides L. no biomonitoramento da poluicao atmosferica na Regiao metropolitana de Sao Paulo - SP, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Caroline R.; Figueiredo, Ana M.G.; Silva, Barbara C. da; Ticianelli, Regina B., E-mail: calbuuquerque@gmail.com, E-mail: anamaria@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Figueira, Rubens C.L., E-mail: aportellar@yahoo.com.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto Oceanografico; Nievola, Catarina C.; Alves, Edenise S.; Domingos, Marisa, E-mail: ccnievola@uol.com.br, E-mail: ealves@ibot.sp.gov.br, E-mail: mmingos@superig.com.br [Instituto de Botanica (IBt-SMA/SP), Sao Paulo, SP (Brazil); Ribeiro, Andreza P., E-mail: andrezp@uninove.br [Universidade Nove de Julho (UNINOVE), Sao Paulo, SP (Brazil)

    2013-07-01

    In this study, it was determined the metals Cd, Cu, Fe, Mo, Ni, Pb and Sb in plant Tillandsia Usneoides L., an epiphyte species popularly known as old beard and able to absorb water and nutrients directly from air, aiming to estimate the contribution of human activities in atmospheric metal pollution in the metropolitan region of Sao Paulo. The samples were collected at five different points, located near the South West and stretches of highway Mario Covas (SP-21). The Neutron Activation Analysis (NAA) and Optical Emission Spectrometry with Inductively Coupled Plasma (ICP-OES) were the analytical techniques used in the quantification of metals of interest.

  13. Test of Monte Carlo Simulation for MoNA neutron detectors

    Science.gov (United States)

    Boone, J. E.; Wantz, A.; Rogers, W. F.; Frank, N.; Kuchera, A. N.; Mosby, S.; Thoennessen, M.; MoNA Collaboration

    2017-09-01

    The MoNA (Modular Neutron Array) and LISA (Large multi-Institutional Scintillator Array) detector systems at NSCL are used to determine the energy and trajectory of neutrons decaying from particle-unbound states in exotic neutron-rich nuclei. In order to test the accuracy of simulation (GEANT4 with Menate_R), important for interpreting scattering data from the arrays, an experiment was recently conducted at Los Alamos LANSCE center using 16 MoNA detectors (each consisting of BC408 organic scintillator plastic measuring 200×10×10 cm3) exposed to a thin, well-characterized neutron beam over a wide energy range in order to observe neutron scattering directly. Neutrons scatter elastically from H and C nuclei and inelastically from C nuclei. Elastic scattering from C (including some inelastic channels) produce light below detector threshold, and therefore constitute ``dark scattering,'' redirecting neutron trajectories without detection, and some inelastic C channels produce additional neutrons in the array. Several features of scattering, including scattering angle, mean distance between scatters, multiplicity, and dark-scatter redirection are analyzed and compared with simulation over a wide range of incoming neutron energy. Results will be presented. Work supported by NSF Grant PHY-1744043.

  14. Study of fodder, urine and bovine milk in marginal region of the Rio das Vellhas, Curvelo - Minas Gerais, Brazil; Estudo de forragem, urina e leite bovino na regiao ribeirinha do Rio da Velhas, Curvelo - Minas Gerais

    Energy Technology Data Exchange (ETDEWEB)

    Veado, Maria Adelaide R.V.; Oliveira, Arno H. de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear]. E-mail: adelaide@nuclear.ufmg.br; heeren@nuclear.ufmg.br; fer@nuclear.ufmg.br; Veado, Julio Cesar C.; Melo, Marilia M. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Escola de Veterinaria. Dept. de Clinica e Cirurgia Veterinarias]. E-mail: cambraia@vet.ufmg.br; Menezes, Maria Angela de B.C [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil). Setor de Radioquimica. Supervisao de Reator e Radioanalise]. E-mail: menezes@urano.cdtn.br

    2000-07-01

    The parametric technique k{sub 0} of neutronic activation was used for determination of elements in samples of bovine urine and milk and fodder plant, of the region of farming production of Curvelo - Minas Gerais, Brazil. The samples had been collected in farms next to the margins to the Rio das Velhas that periodically suffer flooding in the rainy station. Clinical veterinarians studies disclose that many animals created in this region present illnesses with nervous symptomatology, suggestive of a picture of poisoning, however without definite diagnosis. These pathologies frequently are observed after the flooding. In this work had been determined the elements, Cr, Co, Zn among others. The results gotten in the different samples of urine and milk of the studied animals, as well as in the fodder plants, suggest that it has influence of loaded metals for waters of the high course of the basin river of Velhas.

  15. Cross sections of 7Be, 22Na and 24Na for geochemical and cosmochemical important elements by monoenergetic 287 and 370 MeV neutrons

    International Nuclear Information System (INIS)

    Ninomiya, K.; Omoto, T.; Nakagaki, R.

    2011-01-01

    Cross sections of 7 Be, 22 Na and 24 Na for geochemically and cosmochemically important elements were measured at incident neutron energies of 287 and 370 MeV. The cross sections were measured in target exposed to highenergy monoenergetic neutrons at the Research Center for Nuclear Physics (RCNP), Osaka University. (orig.)

  16. Assessment of atmospheric metallic pollution in the metropolitan region of Sao Paulo, Brazil, employing Tillandsia usneoides L. as biomonitor; Avaliacao da poluicao atmosferica por metais na regiao metropolitana de Sao Paulo, Brasil, utilizando a bromelia Tillandsia usneoides L. como biomonitor

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Claudio Ailton

    2006-07-01

    Tillandsia usneoides L. is an epiphytic bromeliad that lives on trees or other kinds of inert substrates, absorbing water and nutrients directly from the environment without roots. Due to its morphological and physiological characteristics, this species accumulates the pollutants present in the atmosphere. In the present work, Tillandsia usneoides was used as a bio monitor of metal atmospheric pollution in Sao Paulo, Brazil, which is the biggest city in South America with a population of 18 million inhabitants and a strong industrial activity. The urban area is polluted by industrial emissions but, according to the Environmental Protection Agency of the State of Sao Paulo (CETESB), the governmental agency of air quality control, regularly occurring emissions from about 7.8 million motor vehicles provide the principal source of air pollution. The Tillandsia samples were collected from an unpolluted area and were exposed bimonthly in 10 sites of the city with different pollution levels and in a control site. After exposure, trace metals were analyzed in the plant by instrumental neutron activation analysis and ICP-MS (Pb, Cd, Co, Cu, Ni, Sb e V). The results of the investigation showed a notable concentration of Co and Ni in the plants exposed in an industrial area where there is a metal processing plant, which produces about 600 tons/year of Co and 16,000 tons/year of Ni. Copper and chromium were equally distributed in industrial regions and in sites near heavy traffic avenues, suggesting that these elements can be associated to both vehicular and industrial sources. A high accumulation of Cd in the plant exposed in industrial areas indicates industrial activities as the main source of this element. For Pb, no evident sources could be identified so far as it was spread evenly along the monitoring sites. Traffic-related elements such as Zn, Ba and Sb presented high concentrations in plants exposed in sites near to heavy traffic avenues (cars, buses and trucks) and

  17. An NaI(Tl) spectrometer system for keV neutron radiative-capture reactions

    International Nuclear Information System (INIS)

    Ohsaki, T.; Nagai, Y.; Igashira, M.; Shima, T.; Suzuki, T.S.; Kikuchi, T.; Kobayashi, T.; Takaoka, T.; Kinoshita, M.; Nobuhara, Y.

    1999-01-01

    An NaI(Tl) spectrometer system has been installed to measure the cross section of a radiative neutron-capture reaction of a nucleus at an astrophysically relevant energy of between 10 and 500 keV. The system consists of two large anti-Compton NaI(Tl) spectrometers and a new data-taking system. The spectrometer can detect a discrete γ-ray emitted promptly from a neutron-capture state to its low-lying state, and the data-taking system can transfer events with much higher rates, about 30-times higher, compared to the existing system

  18. Direct Observation of Neutron Scattering in MoNA Scintillator Detectors

    Science.gov (United States)

    Rogers, W. F.; Mosby, S.; Frank, N.; Kuchera, A. N.; Thoennessen, M.; MoNA Collaboration

    2017-01-01

    Monte Carlo simulations provide an important tool for the interpretation of neutron scattering data in the MoNA and LISA arrays at NSCL. Neutron energy and trajectory are determined by time of flight and position of first light produced in the array. Neutrons elastically scattered from H and inelastically from C typically produce light above detector threshold, while those elastically scattered from C produce light below threshold (``dark scattering'') and are redirected in flight, thus lowering energy and trajectory resolution. In order to test the effectiveness of our Geant4/MENATE_R simulations, we conducted an experiment at the LANSCE facility at Los Alamos National Laboratory to observe scattering of individual neutrons with well defined energy and trajectory in 16 MoNA detector bars arranged in two different stack geometries. Neutrons with energies ranging from 0.5 to 800 MeV emerged from a 3 mm collimator in the 90m shed on the WNR 4FP15L flight path to enter the array at a well defined point. Several features of neutron scattering are compared with simulation predictions, including hit multiplicity, scattering angle, mean distance between scatters, and the effect of dark scatter redirection. Results to date will be presented. Work supported by NSF Grant PHY-1506402.

  19. Neutron Compton scattering as a molecular characterization technique: A study on NaHF2

    International Nuclear Information System (INIS)

    Colognesi, D.; Pietropaolo, A.; Senesi, R.; Ramirez-Cuesta, A. J.

    2007-01-01

    Inelastic neutron scattering experiments were performed at intermediate and high momentum transfers, up to 85-90 A ring -1 , to study the proton momentum distribution in polycrystalline sodium hydrogen fluoride (NaHF 2 ) at low temperature (below 5 K). The H mean kinetic energy was extracted and compared to the results from hydrogen-projected density of phonon states derived from intermediate momentum transfer inelastic neutron scattering and lattice dynamics simulations. A reasonable agreement between the two figures was found. In addition, relevant aspects of high momentum transfer neutron scattering from NaHF 2 were explored in detail, ranging from an alternative evaluation of final state effects to the role played by the instrumental resolution and to the possibility to reconstruct the potential felt by a proton from its momentum distribution

  20. High resolution neutron diffraction study of the ionic conductor β-LiNaSO4

    International Nuclear Information System (INIS)

    Graneli, B.; Fischer, P.; Roos, J.; Brinkmann, D.; Hewat, A.W.

    1992-01-01

    A re-investigation of the structure of β-LiNaSO 4 has been made by means of high resolution neutron powder diffraction. A comparison is made with the original single crystal X-ray measurement. Implications on the conduction mechanism and possible explanations for the differences observed in a NMR investigation are discussed. (orig.)

  1. Surto de sarampo na regiao metropolitana de Campinas, SP

    Directory of Open Access Journals (Sweden)

    Eder Gatti Fernandes

    2013-12-01

    Full Text Available O Brasil não apresenta circulação endêmica do vírus do sarampo desde o ano 2000. Entre maio e junho de 2011, a Região Metropolitana de Campinas, Estado de São Paulo, registrou três casos de sarampo. Foram descritos casos, as medidas de controle, a busca de possível fonte e de casos secundários. A caracterização genotípica do vírus identificou o genótipo D4, circulante no continente europeu. Não foram encontrados casos índice ou secundários. As medidas de controle efetuadas, aliadas à cobertura vacinal adequada da Região Metropolitana de Campinas contribuíram para que a transmissão da doença fosse interrompida.

  2. Study of Ground State Wave-function of the Neutron-rich 29,30Na Isotopes through Coulomb Breakup

    Directory of Open Access Journals (Sweden)

    Rahaman A.

    2014-03-01

    Full Text Available Coulomb breakup of unstable neutron rich nuclei 29,30Na around the ‘island of inversion’ has been studied at energy around 434 MeV/nucleon and 409 MeV/nucleon respectively. Four momentum vectors of fragments, decay neutron from excited projectile and γ-rays emitted from excited fragments after Coulomb breakup are measured in coincidence. For these nuclei, the low-lying dipole strength above one neutron threshold can be explained by direct breakup model. The analysis for Coulomb breakup of 29,30Na shows that large amount of the cross section yields the 28Na, 29Na core in ground state. The predominant ground-state configuration of 29,30Na is found to be 28Na(g.s⊗νs1/2 and 29Na(g.s⊗νs1/2,respectively.

  3. Inhomogeneous strain induced by fast neutron irradiation in NaKSO4 crystals

    International Nuclear Information System (INIS)

    Kandil, S.H.; El Gamal, M.A.; El Khatib, A.; El Wahidy, E.F.

    1987-06-01

    The effect of fast neutron irradiation on the thermal properties of NaKSO 4 crystals was studied around the phase transition temperature T c =453 K. The thermal expansion coefficient as well as the phase transition temperature were found to be dependent upon the irradiation dose. The specific heat, C p , showed multiple peaks in the phase transition temperature region. An explanation of this behaviour was based on the induced inhomogeneous strain in the crystal casued by the neutron irradiation process. (author). 10 refs, 3 figs

  4. Determination of mercury in reference materials and head hair samples of human populations from Serra do Navio, Amapa State, Brazil, by neutron activation analysis method; Analise de mercurio em materiais de referencia e em amostras de cabelo de populacoes da regiao da Serra do Navio (Estado do Amapa) pelo metodo de analise por ativacao de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Catharino, Marilia G.M.; Vasconcellos, Marina B.A.; Paletti, Gerson; Saiki, Mitiko; Favaro, Debora I.T. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Supervisao de Radioquimica

    1996-07-01

    Mercury analysis of human head hair has been of much concern in connection with mercury contamination deriving from gold exploration activities. Neutron activation analysis has been applied as a highly sensitive and accurate method. Total mercury is being determined in hair samples from populations from the regions of Serra do Navio, Tartarugalzinho and Vila Nova, in the Amapa State, Brazil. The reference materials IAEA - 085 and IAEA - 086 were also analysed. The range of total mercury analysis is o,21 - 18,84 ppm. These results show a possible contamination, comparing to a control group analysed. (author)

  5. Investigation of the single Particle Structure of the neutron-rich Sodium Isotopes $^{27-31}\\!$Na

    CERN Multimedia

    2002-01-01

    We propose to study the single particle structure of the neutron-rich isotopes $^{27-31}\\!$Na. These isotopes will be investigated via neutron pickup reactions in inverse kinematics on a deuterium and a beryllium target. Scattered beam particles and transfer products are detected in a position sensitive detector located around 0$^\\circ$. De-excitation $\\gamma$-rays emitted after an excited state has been populated will be registered by the MINIBALL Germanium array. The results will shed new light on the structure of the neutron-rich sodium isotopes and especially on the region of strong deformation around the N=20 nucleus $^{31}\\!$Na.

  6. Avaliação da presença de metais e de biomarcadores fecais em sedimentos do Rio Barigui na Região Metropolitana de Curitiba-PR

    OpenAIRE

    Martins, Raquel Fernandes

    2010-01-01

    Resumo: Neste trabalho investigou-se a composicao de sedimentos da Bacia do Rio Barigui, situado na regiao metropolitana de Curitiba, sul do Brasil. Este rio atravessa, alem de Curitiba, varios municipios vizinhos. Nos ultimos anos, devido ao crescimento e a ocupacao desordenada ao longo do rio, alem da falta de servico de saneamento, a Bacia sofre com o lancamento de grande quantidade de esgoto domestico sem tratamento. Programas atuais de monitoramento de bacias usam parametros fisico-quimi...

  7. Use of Remote Sensing and Local Knowledge for Geoconservation of Regiao dos Lagos, Brazil

    Science.gov (United States)

    Avelar, S.; Vasconcelos, G.; Mansur, K. L.; Anjos, S. C.

    2013-12-01

    A series of lagoons can be found along the coastline of Rio de Janeiro, in the so-called Regiao dos Lagos. The lagoons differ in size, physicochemical, sedimentological and biological characteristics. Rare examples of litifying microbialites that produce stromatolites, the oldest fossils on Earth, can be found living in this lagoon system. The occurrence of stromatolites in the region is of great scientific interest because it enables the study of possible analogues of the earliest life on Earth. However, this region has been suffering from intense human activities and degradations. Geoconservation planning requires an assessment of the characteristics of the region and its potential threats. The primary goal of this study is to assess physical environmental changes and anthropogenic impacts over the last four decades in Regiao dos Lagos. Using a broad integrative assessment combining remote sensing, GIS, field studies and local knowledge of communities, land-cover and land-use classes were identified, as well as the main human activities impacting the environment. The seasonal and weekend tourism and urban sprawl in this coastal area of Rio de Janeiro triggers the occupation of new areas and the removal of natural vegetation, especially on lagoon margins. This disorderly occupation by an ever increasing population, with both legal and illegal constructions and the subsequent overload of the local infrastructure, e.g. increase of electrical energy consumption, volume of vehicles, pollution in air, water and soil and problems with water supply and wastewater treatment, are hastening the gradual degradation of the lake ecosystem. The main driving forces to environmental changes over the last four decades in Regiao dos Lagos were the change of dense vegetation, saline and bare soil classes into built-up areas, adding to the poor waste treatment and inadequate sewage disposal. This analysis provides a basis for a better control of anthropogenic impacts and

  8. Sodium Ion Transport Mechanisms in Antiperovskite Electrolytes Na3OBr and Na4OI2: An in Situ Neutron Diffraction Study.

    Science.gov (United States)

    Zhu, Jinlong; Wang, Yonggang; Li, Shuai; Howard, John W; Neuefeind, Jörg; Ren, Yang; Wang, Hui; Liang, Chengdu; Yang, Wenge; Zou, Ruqiang; Jin, Changqing; Zhao, Yusheng

    2016-06-20

    Na-rich antiperovskites are recently developed solid electrolytes with enhanced sodium ionic conductivity and show promising functionality as a novel solid electrolyte in an all solid-state battery. In this work, the sodium ionic transport pathways of the parent compound Na3OBr, as well as the modified layered antiperovskite Na4OI2, were studied and compared through temperature-dependent neutron diffraction combined with the maximum entropy method. In the cubic Na3OBr antiperovskite, the nuclear density distribution maps at 500 K indicate that sodium ions hop within and among oxygen octahedra, and Br(-) ions are not involved. In the tetragonal Na4OI2 antiperovskite, Na ions, which connect octahedra in the ab plane, have the lowest activation energy barrier. The transport of sodium ions along the c axis is assisted by I(-) ions.

  9. Irradiation of 4''x4'' NaI(Tl) detector by the 14 MeV neutrons.

    Science.gov (United States)

    Sudac, D; Valkovic, V

    2010-01-01

    Within the EURopean Illicit TRAfficking Countermeasures Kit (EURITRACK) project, a new Tagged Neutron Inspection System (TNIS) has been developed and installed in the Port of Rijeka in Croatia. The system was based on the examination of sea containers with the 14 MeV neutron beam. During the operation the characteristic gamma rays were produced and measured by several 5''x5''x10'' NaI(Tl) detectors. During this procedure some of the detectors were exposed to an intensive neutron beam radiation. It was necessary to check for possible radiation damage of the NaI(Tl) scintillator during the gamma detector selection phase of the project. The 4''x4'' NaI(Tl) detector was exposed to 14 MeV neutrons for 20 h. From the presented results on energy resolution and activation measurements it could be concluded that there are no significant differences in energy resolution before and after the irradiation by 4.7x10(11) of 14 MeV neutrons. The only problem could be the high level of medium and long term induced activity in the energy region below 2 MeV. Copyright 2009 Elsevier Ltd. All rights reserved.

  10. Neutron activation analysis of Cl, K and Na content in whole blood of horses used in hyperimmune sera production

    International Nuclear Information System (INIS)

    Baptista, T.S.; Zamboni, C.B.; Medeiros, J.A.G.; Freitas, M.G.; Higashi, H.G.; Marcelino, J.R.

    2009-01-01

    Using neutron activation analysis technique Cl, K and Na concentration were obtained in whole blood of equines used for antivenom production at Butantan Institute (Sao Paulo, Brazil). These data were compared with the human whole blood estimation. No significant difference was observed suggesting that this model animal is adequate sera production. (author)

  11. Hydrogen dynamics in Na3AlH6: A combined density functional theory and quasielastic neutron scattering study

    DEFF Research Database (Denmark)

    Voss, Johannes; Shi, Qing; Jacobsen, Hjalte Sylvest

    2007-01-01

    alanate with TiCl3, and here we study hydrogen dynamics in doped and undoped Na3AlH6 using a combination of density functional theory calculations and quasielastic neutron scattering. The hydrogen dynamics is found to be vacancy mediated and dominated by localized jump events, whereas long-range bulk...

  12. Lattice dynamics of NaI studied by inelastic neutron scattering: absence of thermally induced discrete breathers

    Czech Academy of Sciences Publication Activity Database

    Kempa, Martin; Ondrejkovič, Petr; Bourges, P.; Márton, Pavel; Hlinka, Jiří

    2014-01-01

    Roč. 89, č. 5 (2014), "054308-1"-"054308-5" ISSN 1098-0121 R&D Projects: GA ČR GPP204/11/P404 Institutional support: RVO:68378271 Keywords : NaI * alkali halides * inelastic neutron scattering * discrete breathers Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.736, year: 2014

  13. Determination of Na, Mg, Al, Si, K, Cl, Ca and Fe in cigarette tobacco by fast neutron activation analysis

    International Nuclear Information System (INIS)

    Cam, N.F.; Yaprak, G.; Erduran, M.N.

    1999-01-01

    FNAA has been, for many years, a technique for the non-destructive analysis of a wide variety of sample materials - liquids, solids and powders. The important advantages of fast neutron activation analysis are good analytical sensitivity without sample preparation, accuracy and total analysis in a short time. In our work, the concentrations of the elements Na, Mg, Al, Si, K, Cl, Ca and Fe, were determined in cigarette tobacco of two brands commercially available in Turkey using 14.6 MeV neutron activation analysis. (author)

  14. Revised Production Rates for Na-22 and Mn-54 in Meteorites Using Cross Sections Measured for Neutron-induced Reactions

    Science.gov (United States)

    Sisterson, J. M.; Kim, K. J.; Reedy, R. C.

    2004-01-01

    The interactions of galactic cosmic rays (GCR) with extraterrestrial bodies produce small amounts of radionuclides and stable isotopes. The production rates of many relatively short-lived radionuclides, including 2.6-year Na-22 and 312-day Mn-54, have been measured in several meteorites collected very soon after they fell. Theoretical models used to calculate production rates for comparison with the measured values rely on input data containing good cross section measurements for all relevant reactions. Most GCR particles are protons, but secondary neutrons make most cosmogenic nuclides. Calculated production rates using only cross sections for proton-induced reactions do not agree well with measurements. One possible explanation is that the contribution to the production rate from reactions initiated by secondary neutrons produced in primary GCR interactions should be included explicitly. This, however, is difficult to do because so few of the relevant cross sections for neutron-induced reactions have been measured.

  15. Study of single particle properties of neutron-rich Na isotopes on the "shore of the island of inversion" by means of neutron-transfer reactions

    CERN Multimedia

    Reiter, P; Blazhev, A A; Riisager, K; Bastin, B; Tengborn, E A; Kruecken, R; Voulot, D; Jeppesen, H B; Hadinia, B; Gernhaeuser, R A; Fynbo, H O U; Georgiev, G P; Habs, D; Fraile prieto, L M; Chapman, R; Nilsson, T; Diriken, J V J; Jenkins, D G; Kroell, T; Leske, J; Huyse, M L; Patronis, N

    We aim at the investigation of single particle properties of neutron-rich Na isotopes around the "shore of the island of inversion". As first experiment of this programme, we propose to study excited states in the isotope $^{29}$Na by a one-neutron transfer reaction with a $^{28}$Na beam at 3 MeV/u obtained from REX-ISOLDE impinging on a CD$_{2}$-target. The $\\gamma$-rays will be detected by the MINIBALL array and the particles by the T-REX array of segmented Si detectors. The main physics aims are to extract from the relative spectroscopic factors information on the configurations contributing to the wave functions of the populated states and, secondly, to identify and characterize negative parity states whose excitation energies reflect directly the N= 28 gap in this region. The results will be compared to recent shell model calculations involving new residual interactions. This will shed new light on the evolution of single particle structure and help to understand the underlying physics relevant for the f...

  16. Basics of Neutrons for First Responders

    Energy Technology Data Exchange (ETDEWEB)

    Rees, Brian G. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2018-02-05

    These are slides from a presentation on the basics of neutrons. A few topics covered are: common origins of terrestrial neutron radiation, neutron sources, neutron energy, interactions, detecting neutrons, gammas from neutron interactions, neutron signatures in gamma-ray spectra, neutrons and NaI, neutron fluence to dose (msV), instruments' response to neutrons.

  17. Design of a Ge-NaI(Tl) Compton suppression spectrometer and its use in neutron activation analysis

    International Nuclear Information System (INIS)

    Petra, M.; Swift, G.; Landsberger, S.

    1990-01-01

    A Compton suppression spectrometer consisting of a germanium detector surrounded by a NaI(Tl) shield and its performance are described. The system reduces the Compton continuum, thus making possible the identification of low-intensity peaks. This allows the determination of small amounts of various elements in biological and environmental materials following neutron activation. Representative results for arsenic in biological materials are presented. (orig.)

  18. Measurement of the relationship of {sup 24} Na activity and the received neutron dose; Medicion de la relacion de la actividad de {sup 24}Na y la dosis de neutrones recibida

    Energy Technology Data Exchange (ETDEWEB)

    Gossio, S.; Carrelli, J.; Villella, A.; Soppe, E., E-mail: sgossio@arn.gob.ar [Autoridad Regulatoria Nuclear (ARN), Buenos Aires (Argentina)

    2013-07-01

    In cases of criticality accidents it is required a fast dosimetric system that allows to evaluate the doses of the personnel involved. The reaction (n,y) with sodium presented in the body ({sup 23}Na), generates {sup 24}Na, that emits two gamma of 1369KeV and 2754 KeV that can be measured using a whole body counter. The experienced were carried out with the irradiation of {sup 252} Cf of a phantom with a solution of NaCl in water. After the irradiation it was measured the {sup 24}Na activity in the whole body counter, which has a HPGe detector previously calibrated in energy and efficiency. Considering the correction by decay, the quantity of {sup 23}Na presented in the body of an adult and elimination curve of {sup 24}Na, it was established a coefficient of neutronic doses by unity of activity of {sup 24}Na measured in the whole body counter. This method is useful for the retrospective estimation of the doses, as well as to carry out a radiological sorting in case of criticality.

  19. A combined diffraction (XRD, electron and neutron) and electrical study of Na3MoO3F3

    International Nuclear Information System (INIS)

    Brink, F.J.; Noren, Lasse; Goossens, D.J.; Withers, R.L.; Liu Yun; Xu, C.-N.

    2003-01-01

    Na 3 MoO 3 F 3 , a member of the A 2 BM VI O 3 F 3 family of elpasolite-related oxyfluorides, has been prepared by the reaction of NaF with MoO 3 at 650 deg. C. It is shown by a combined X-ray, electron and neutron diffraction study, that the true symmetry of Na 3 MoO 3 F 3 is not monoclinic (pseudo-orthorhombic) as previously reported but instead triclinic (metrically rhombohedral) P1. The superstructure unit cell is given by a=-a R +b R , b=c R , c=(a R +b R +c R ), when expressed with respect to the underlying rhombohedral parent structure. Neutron diffraction refinement of the rhombohedral sub-structure shows O and F to be fully ordered with alternate (111) R planes being occupied by O and then F. The nature of the distortion away from the high temperature Fm3-barm parent structure is consistent with a combination of phiphiphi type rotations of the octahedral framework together with ppp type displacements of the octahedral cations, which is not observed in any of the closely related A 2 BM VI O 3 F 3 family members. Bond valence arguments are used to give a plausible explanation for this difference in behavior

  20. Nickel and chromium release from stents into isotonic NaCl solution investigated with the aid of neutron activation analysis

    International Nuclear Information System (INIS)

    Lin, X.; Portenlaenger, G.; Henkelmann, R.; Schulz, Ch.; Alt, E.

    1999-01-01

    Stent placement has become an effective treatment for abrupt or threatened vessel closure in recent years. As a preliminary investigation on the allergy problem towards to Ni and Cr metals from implanted stent, the release of the two elements from stents into isotonic NaCl solution was investigated. Trace amounts of Ni and Cr metals released from stents are successfully determined by neutron activation analysis (NAA). An extreme experimental condition is applied in the NAA procedure to reach a low detection limit of 1 ng Ni. A conclusion is given about the influence on the Ni and Cr release from gold coating, from the expansion, and from the different incubation periods. (author)

  1. Fast dynamics of Na 0.5Li 0.5PO 3 observed by coherent neutron scattering

    Science.gov (United States)

    Rufflé, B.; Beaufils, S.; Etrillard, J.; Coddens, G.; Toudic, B.; Ecolivet, C.

    1997-02-01

    Experimental results obtained by coherent neutron scattering with the time of flight spectrometer MIBEMOL on the less-fragile glass-forming liquid Na 0.5Li 0.5PO 3 are presented. A qualitative discussion of the susceptibility spectra within the framework of the simplest version of the mode-coupling theory locates a possible crossover temperature Tc near 620 K (∼1.2 Tg) close to the temperature of the decoupling phenomena of the relaxation time scales observed by 31P NMR.

  2. Structure of 2 molar NaOH in aqueous solution from neutron diffraction and empirical potential structure refinement

    International Nuclear Information System (INIS)

    McLain, Sylvia E.; Imberti, Silvia; Soper, Alan K.; Botti, Alberto; Bruni, Fabio; Ricci, Maria Antonietta

    2006-01-01

    Neutron diffraction with isotopic substitution has been used to investigate aqueous solutions of 2M NaOH in the liquid state. The data were modeled using empirical potential structure refinement which allows for the extraction of the ion-water and water-water correlations. The data show that the ion-water radial distribution functions are in accordance with those found by previous studies on NaOH solutions and follow a trend which is dependent on the concentration of the solute. In particular, the shape of the hydroxide hydration shell is found to be concentration independent, but the number of water molecules occupying this shell increases with dilution. Additionally, the water-water correlations show that there is still a measurable effect on water structure with the addition of ions at this concentration, as the second shell in the water oxygen radial distribution function is compressed relative to the first shell. The data are also used to discuss the recent claims that the published radial distribution functions of water are unreliable, showing that data taken at different neutron sources, with different diffraction geometry and systematic errors lead to the same structural information when analyzed via a realistic modeling regime

  3. Crystal structures of spinel-type Na2MoO4 and Na2WO4 revisited using neutron powder diffraction

    Directory of Open Access Journals (Sweden)

    A. Dominic Fortes

    2015-06-01

    Full Text Available Time-of-flight neutron powder diffraction data have been collected from Na2MoO4 and Na2WO4 to a resolution of sin (θ/λ = 1.25 Å−1, which is substantially better than the previous analyses using Mo Kα X-rays, providing roughly triple the number of measured reflections with respect to the previous studies [Okada et al. (1974. Acta Cryst. B30, 1872–1873; Bramnik & Ehrenberg (2004. Z. Anorg. Allg. Chem. 630, 1336–1341]. The unit-cell parameters are in excellent agreement with literature data [Swanson et al. (1962. NBS Monograph No. 25, sect. 1, pp. 46–47] and the structural parameters for the molybdate agree very well with those of Bramnik & Ehrenberg (2004. However, the tungstate structure refinement of Okada et al. (1974 stands apart as being conspicuously inaccurate, giving significantly longer W—O distances, 1.819 (8 Å, and shorter Na—O distances, 2.378 (8 Å, than are reported here or in other simple tungstates. As such, this work represents an order-of-magnitude improvement in precision for sodium molybdate and an equally substantial improvement in both accuracy and precision for sodium tungstate. Both compounds adopt the spinel structure type. The Na+ ions have site symmetry .-3m and are in octahedral coordination while the transition metal atoms have site symmetry -43m and are in tetrahedral coordination.

  4. Deep inelastic neutron scattering on 207Pb and NaHF2 as a test of a detectors array on the VESUVIO spectrometer

    International Nuclear Information System (INIS)

    Pietropaolo, A.; Senesi, R.

    2008-01-01

    A prototype array of resonance detectors for deep inelastic neutron scattering experiments has been installed on the VESUVIO spectrometer, at the ISIS spallation neutron source. Deep inelastic neutron scattering measurements on a reference lead sample and on NaHF 2 molecular system are presented. Despite on an explorative level, the results obtained for the values of mean kinetic energy k > are found in good agreement with the theoretical predictions, thus assessing the potential capability of the device for a routine use on the instrument

  5. Deep inelastic neutron scattering on {sup 207}Pb and NaHF{sub 2} as a test of a detectors array on the VESUVIO spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Pietropaolo, A. [Universita degli Studi di Roma Tor Vergata, Dipartimento di Fisica and Centro NAST - Nanoscienze and Nanotecnologie and Strumentazione, via della Ricerca Scientifica 1, 00133 Rome (Italy)], E-mail: antonino.pietropaolo@roma2.infn.it; Senesi, R. [Universita degli Studi di Roma Tor Vergata, Dipartimento di Fisica and Centro NAST - Nanoscienze and Nanotecnologie and Strumentazione, via della Ricerca Scientifica 1, 00133 Rome (Italy)

    2008-01-11

    A prototype array of resonance detectors for deep inelastic neutron scattering experiments has been installed on the VESUVIO spectrometer, at the ISIS spallation neutron source. Deep inelastic neutron scattering measurements on a reference lead sample and on NaHF{sub 2} molecular system are presented. Despite on an explorative level, the results obtained for the values of mean kinetic energy are found in good agreement with the theoretical predictions, thus assessing the potential capability of the device for a routine use on the instrument.

  6. Determination of Au, Sb, As, Br, Na, K, Cd, Mn and Cl in rice from Vietnam by neutron activation analysis

    International Nuclear Information System (INIS)

    Tran Van, L.; Teherani, D.K.

    1988-01-01

    Gold, antimony, arsenic, bromine, sodium, potassium, cadmium, manganese and chlorine were determined by neutron activation analysis in various rice seed, brand layer and husk samples from Vietnam. The following concentration values were found: Au 0.05-0.28 ppm, Sb 0.05-1.08 ppm, As 0.08-0.94 ppm, Br 0.82-6.72 ppm, Na 16.71-25.71 ppm, K 2582-5163 ppm, Mn 19.26-33.43 ppm, Cd 0.51-2.42 ppm and Cl 205.20-828.61 ppm in rice seed. Statistically significant differences in Au, Sb, Cd contents were detected in rice seed and husk, as well as brand layer and husk. (author) 8 refs.; 3 figs

  7. Unconventional spin order in the triangular lattice system NaCrO2: A neutron scattering study

    International Nuclear Information System (INIS)

    Hsieh, D.; Qian, D.; Berger, R.F.; Cava, R.J.; Lynn, J.W.; Huang, Q.; Hasan, M.Z.

    2008-01-01

    We report high resolution neutron scattering measurements on the rhombohedrally stacked triangular antiferromagnet NaCrO 2 which has recently been shown to exhibit an unusually broad fluctuating cross-over regime extending far below the onset of spin freezing at T c . Our results show that at T c purely two-dimensional quasi-static spin correlations of the 120 o type exist. Below some cross-over temperature (T∼0.75T c ) a small incommensuration develops which helps resolve the inter-layer spin frustration and drives short-range three-dimensional magnetic order. This incommensuration assisted dimensional cross-over suggests that inter-layer frustration is responsible for stabilizing the rare 2D correlated phase above 0.75T c

  8. Influence of density and chemical composition of soils in the neutrons probes answer; Influencia da densidade e da composicao quimica dos solos na resposta de sondas de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Crispino, Marcos Luiz; Antonino, Antonio Celso Dantas; Dall`Olio, Attilio; Oliveira Lira, Carlos Alberto Brayner de [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear; Carneiro, Clemente J. Gusmao [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    1996-08-01

    The determination of soil humidity with neutron probes is based in the measure of the thermal neutron flux intensity and its behavior with the soil depend: soil`s chemical composition; soils physical parameters; neutrons` energetic spectrum and neutron-source detector geometry.The objective of this paper is to apply the multigroup function theory to calculate a neutron probe calibration curve utilizing representatives parameters and coefficients of soils horizons in a experimental station in Zona da Mata, Pernambuco, Brazil 2 tabs., 3 figs.

  9. Neutron diffraction study of sodium hydrogen selenate Na3H5(SeO4)4. Comparison with the X-ray diffraction data

    International Nuclear Information System (INIS)

    Troyanov, S.I.; Zakharov, M.A.; Reehuis, M.; Kemnitz, E.

    2002-01-01

    The neutron diffraction study of Na 3 H 5 (SeO 4 ) 4 single crystals at 298 and 85 K has confirmed the positions of nonhydrogen atoms obtained in the X-ray diffraction study. Contrary to the X-ray diffraction data, the neutron diffraction data indicate that all the three independent protons are ordered and participate in two asymmetric and one symmetric hydrogen bonds, with the O···O distances being 2.68, 2.61, and 2.48 A. The system of hydrogen bonds is built by complicated chains

  10. Transport of hazardous materials in the Amazon area; Transporte de produtos perigosos na regiao Amazonica

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Wallace de Castro [FURNAS Centrais Eletricas S.A., Rio de Janeiro, RJ (Brazil); Fernandes, Elton; Nassi, Carlos David [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE)

    2008-07-01

    Amongst several exploratory sources of the subject 'hazardous materials transport', it is distinguished: 'the threat to the environment'. This paper presents an exploratory investigation of this subject line in the Amazon region. In view of the diversity of 'existing hazardous materials' and the raised dimension of the oil transport and its derivatives in this context, this paper focused in these products. Regarding to the geographic region, the approach was given to the State of Amazon, considering the amplitude of this State in the Amazon region and the availability of data. Therefore, this work explores and analyzes macro aspects inherent to the State of Amazon pertinent to the oil transport and its derivatives. In the macro context, it is observed the necessity of a higher control in the transport of hazardous materials in the region. The absence of registered data and the unfamiliarity on the risks related to the transport of hazardous materials by authorities and transporters indicate a relative absence of qualification in the region to deal with the monitoring of the transport of hazardous materials. So far, it is not possible up till now to make any evaluation of the environment threats of accidents with transport of hazardous materials in the Amazon region.(author)

  11. Shape coexistence in the N=19 neutron-rich nucleus 31Mg explored by β–γ spectroscopy of spin-polarized 31Na

    Directory of Open Access Journals (Sweden)

    H. Nishibata

    2017-04-01

    Full Text Available The structure of excited states in the neutron-rich nucleus 31Mg, which is in the region of the “island of inversion” associated with the neutron magic number N=20, is studied by β–γ spectroscopy of spin-polarized 31Na. Among the 31Mg levels below the one neutron separation energy of 2.3 MeV, the spin values of all five positive-parity levels are unambiguously determined by observing the anisotropic β decay. Two rotational bands with Kπ=1/2+ and 1/2− are proposed based on the spins and energies of the levels. Comparison on a level-by-level basis is performed between the experimental results and theoretical calculations by the antisymmetrized molecular dynamics (AMD plus generator coordinate method (GCM. It is found that various nuclear structures coexist in the low excitation energy region in 31Mg.

  12. Hydrogen dynamics in Na3AlH6: A combined density functional theory and quasielastic neutron scattering study

    DEFF Research Database (Denmark)

    Zsigmond, G.; Manoshin, S.; Lieutenant, K.

    2007-01-01

    Handling of polarization became very important in simulations of neutron scattering. One of the very comprehensive and open-source neutron simulation package, VITESS, has been intensely involved in polarized neutron simulations. Several examples will be shown here. Another similar package NISP also...

  13. Coulomb excitation of neutron-rich$^{28,29,30}$Na nuclei with MINIBALL at REX-ISOLDE: Mapping the borders of the island of inversion

    CERN Multimedia

    Butler, P; Cederkall, J A; Reiter, P; Wiens, A; Blazhev, A A; Kruecken, R; Voulot, D; Kalkuehler, M; Wadsworth, R; Gernhaeuser, R A; Hess, H E; Holler, A; Finke, F; Leske, J; Huyse, M L; Seidlitz, M

    We propose to study the properties of neutron-rich nuclei $^{28,29,30}$Na via Coulomb excitation experiments using the REX-ISOLDE facility coupled with the highly efficient MINIBALL array. Reliable B(E2,0$^{+}$ $\\rightarrow$ 2$^{+}$) values for $^{30,32}$Mg were obtained at ISOLDE. Together with recent new results on $^{31}$Mg, collective and single particle properties are probed for Z=12 at the N=20 neutron closed shell, the 'island of inversion'. We would like to extend this knowledge to the neighbouring $^{28,29,30}$Na isotopes where a different transition from the usual filling of the neutron levels into the region with low lying 2p-2h cross shell configurations is predicted by theory. Detailed theoretical predictions on the transition strength in all three Na nuclei are awaiting experimental verification and are the subject of this proposal. At REX beam energies of 3.0 MeV /nucleon the cross-sections for Coulomb excitation are sufficient. Moreover the results from the close-by $^{30,31,32}$Mg nuclei de...

  14. Feasibility Study of Neutron Multiplicity Assay for a Heterogeneous Sludge Sample containing Na, Pu and other Impurities

    International Nuclear Information System (INIS)

    Nakamura, H.; Nakamichi, H.; Mukai, Y.; Yoshimoto, K.; Beddingfield, D.H.

    2010-01-01

    To reduce radioactivity of liquid waste generated at PCDF, a neutralization precipitation processes of radioactive nuclides by sodium hydroxide is used. We call the precipitate a 'sludge' after calcination. Pu mass in the sludge is normally determined by sampling and DA within the required uncertainty on DIQ. Annual yield of the mass is small but it accumulates and reaches to a few kilograms, so it is declared as retained waste and verified at PIV. A HM-5-based verification is applied for sludge verification. The sludge contains many chemical components. For example, Pu (-10wt%), U, Am, SUS components, halogens, NaNO 3 (main component), residual NaOH, and moisture. They are mixed together as an impure heterogeneous sludge sample. As a result, there is a large uncertainty in the sampling and DA that is currently used at PCDF. In order to improve the material accounting, we performed a feasibility study using neutron multiplicity assay for impure sludge samples. We have measured selected sludge samples using a multiplicity counter which is called FCAS (Fast Carton Assay System) which was designed by JAEA and Canberra. The PCDF sludge materials fall into the category of 'difficult to measure' because of the high levels of impurities, high alpha values and somewhat small Pu mass. For the sludge measurements, it was confirmed that good consistency between Pu mass in a pure sludge standard (PuO 2 -Na 2 U 2 O 7 , alpha=7) and the DA could be obtained. For unknown samples, using 14-hour measurements, we could obtain quite low statistical uncertainty on Doubles (-1%) and Triples (-10%) count rate although the alpha value was extremely high (15-25) and FCAS efficiency was relatively low (40%) for typical multiplicity counters. Despite the detector efficiency challenges and the material challenges (high alpha, low Pu mass, heterogeneous matrix), we have been able to obtain assay results that greatly exceed the accountancy requirements for retained waste materials. We have

  15. Analysis of Cl, Mn, Na, Zn in Food Samples by a Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Jong Hwa; Kim, Sun Ha; Chung, Yong Sam [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Ok Hee [YongIn University, Yongin (Korea, Republic of)

    2008-10-15

    Due to their westernized dietary habit, Korean children are still threatened by the increasing risks of chronic disease such as obesity, hypertension, low immunity, etc. In addition, they are often exposed to a deficiency of Ca, Mg, Fe and micro-minerals which are necessary for their growth, immunity, and prevention of anemia. Nonetheless, the nutritional adequacy of mineral intakes for children is difficult to assess because of a lack of related studies and a nutritional database with respect to Korean children's foods. In this study, ninety kinds of foods consisting of lunch meals from an elementary and a middle school and children's favorite snacks were collected and prepared for an analysis. INAA which has an advantage of a non-destructive technique was employed to determine the elements like Cl, Mn, Na, Cl in the pretreated food samples. Quality control was carried out by using certified reference materials. From the analytical results, elemental concentration range in the collected samples according to the food groups was summarized.

  16. Analysis of Cl, Mn, Na, Zn in Food Samples by a Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Moon, Jong Hwa; Kim, Sun Ha; Chung, Yong Sam; Lee, Ok Hee

    2008-01-01

    Due to their westernized dietary habit, Korean children are still threatened by the increasing risks of chronic disease such as obesity, hypertension, low immunity, etc. In addition, they are often exposed to a deficiency of Ca, Mg, Fe and micro-minerals which are necessary for their growth, immunity, and prevention of anemia. Nonetheless, the nutritional adequacy of mineral intakes for children is difficult to assess because of a lack of related studies and a nutritional database with respect to Korean children's foods. In this study, ninety kinds of foods consisting of lunch meals from an elementary and a middle school and children's favorite snacks were collected and prepared for an analysis. INAA which has an advantage of a non-destructive technique was employed to determine the elements like Cl, Mn, Na, Cl in the pretreated food samples. Quality control was carried out by using certified reference materials. From the analytical results, elemental concentration range in the collected samples according to the food groups was summarized

  17. Combined atomistic simulation and quasielastic neutron scattering study of the low-temperature dynamics of hydrogen and deuterium confined in NaX zeolite.

    Science.gov (United States)

    Pantatosaki, Evangelia; Papadopoulos, George K; Jobic, Hervé; Theodorou, Doros N

    2008-09-18

    A direct comparison of quasielastic neutron scattering experimental measurements and molecular dynamics computer simulations is carried out for the first time for hydrogen and deuterium confined in the nanostructure of faujasite type zeolites at a temperature of 100 K, in order to investigate the dependence of sorption thermodynamics and sorbate dynamics on the sorbed phase concentration. The charged crystal framework of NaX is digitally reconstructed based on X-ray diffraction spectra, with the compensating Na + positions determined by neutron diffraction data. For the quantum statistical mechanical description of the guest-guest and guest-zeolite interactions, the temperature-dependent effective potential of Feynman and Hibbs is employed, resulting from an approximation to the quantum mechanical path integral formulation of the motion. Computer simulation and neutron scattering are found in satisfactory agreement, both exhibiting a slight increase of the self-diffusivity and a maximum in the transport diffusivity as a function of sorbate loading. Our findings are further elaborated on the basis of the quasichemical mean field theory in conjunction with a model for surface transport due to Reed and Ehrlich, through which the computed and measured dynamical behavior can be related to the strength of interactions between the sorbate molecules.

  18. Study by Monte Carlo methods of an explosives detection system made up with a D-D neutron generator and NaI(Tl) gamma detectors.

    Science.gov (United States)

    Cevallos Robalino, Lenin E; García Fernández, Gonzalo Felipe; Gallego, Eduardo; Guzmán-García, Karen A; Vega-Carrillo, Hector Rene

    2018-02-17

    Detection of hidden explosives is of utmost importance for homeland security. Several configurations of an Explosives Detection System (EDS) to intercept hidden threats, made up with a Deuterium-Deuterium (D-D) compact neutron generator and NaI (Tl) scintillation detectors, have been evaluated using MCNP6 code. The system's response to various samples of explosives, such as RDX and Ammonium Nitrate, is analysed. The D-D generator is able to produce fast neutrons with 2.5 MeV energy in a maximum yield of 10 10 n/s. It is surrounded by high-density polyethylene to thermalize the fast neutrons and to optimize interactions with the sample inspected, whose emission of gamma rays gives a characteristic spectrum of the elements that constitute it. This procedure allows to determine its chemical composition and to identify the type of substance. The necessary shielding is evaluated to estimate its thicknesses depending on the admissible dose of operation, using lead and polyethylene. The results show that its functionality is promising in the field of national security for explosives inspection. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Influência do tempo de contagem na determinação da densidade de nêutrons Influence of the counting time on neutron density determination

    Directory of Open Access Journals (Sweden)

    Antônio R. S. de Andrade

    2001-12-01

    Full Text Available Com o objetivo de se estudar a influência do tempo de contagem na determinação da densidade de nêutrons moderados com uma sonda de nêutrons, num Latossolo localizado na área experimental do Departamento de Engenharia Rural, da Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Campus de Botucatu, SP, coletaram-se dados no interior de uma estufa de polietileno, a três profundidades no solo, 15, 30 e 45 cm, com tempos de contagem de 1, 4, 16, 32, 64, 128 e 256 s, com cinco repetições. Para avaliação da variabilidade entre as leituras, utilizaram-se métodos estatísticos descritivos: variância, desvio-padrão, valores de amplitude e coeficiente de variação. Para se determinar a influência do tempo de contagem no valor das leituras, utilizou-se o teste F e comparação entre médias através do teste de Tukey. Com exceção da profundidade de 45 cm, observou-se pequena variabilidade entre as leituras obtidas para cada tempo de contagem e uma significante variação entre as médias das leituras obtidas com curtos (1 e 4 s e longos (tempos maiores de 16 s tempos de contagem. O uso de longos tempos de contagem (maiores de 32 s não ocasiona diferença significativa na magnitude das leituras.To study the influence of the neutron probe counting time on neutron density determination a study was carried out on a Latossol, under greenhouse conditions, at the Experimental Station of the Rural Engineering Department, UNESP in Botucatu-SP. Neutron probe data were collected, with five replicates, at three soil depths (15, 30 and 45 cm with counting times of 1, 4, 16, 32, 128 and 256 s. To evaluate the variability among replicates, conventional statistics parameters were determined : variance, standard deviation, amplitude and coefficient of variation; to determine the influence of the counting time on neutron density determination, analyses of variance (F test and comparisons of means (Tukey Test were also conducted. The

  20. Use of reference materials for validating analytical methods. Applied to the determination of As, Co, Na, Hg, Se and Fe using neutron activation analysis

    International Nuclear Information System (INIS)

    Munoz, L; Andonie, O; Kohnenkamp, I

    2000-01-01

    The main purpose of an analytical laboratory is to provide reliable information on the nature and composition of the materials submitted for analysis. This purpose can only be attained if analytical methodologies that have the attributes of accuracy, precision, specificity and sensitivity, among others, are used. The process by which these attributes are evaluated is called validation of the analytical method. The Chilean Nuclear Energy Commission's Neutron Activation Analysis Laboratory is applying a quality guarantee program to ensure the quality of its analytical results, which aims, as well, to attain accreditation for some of its measurements. Validation of the analytical methodologies used is an essential part of applying this program. There are many forms of validation, from comparison with reference techniques to participation in inter-comparison rounds. Certified reference materials were used in this work in order to validate the application of neutron activation analysis in determining As, Co, Na, Hg, Se and Fe in shellfish samples. The use of reference materials was chosen because it is a simple option that easily detects sources of systematic errors. Neutron activation analysis is an instrumental analytical method that does not need chemical treatment and that is based on processes which take place in the nuclei of atoms, making the matrix effects unimportant and different biological reference materials can be used. The following certified reference materials were used for validating the method used: BCR human hair 397, NRCC dogfish muscle DORM-2, NRCC -dogfish liver DOLT-2, NIST - oyster tissue 1566, NIES - mussel 6 and BCR - tuna fish 464. The reference materials were analyzed using the procedure developed for the shellfish samples and the above-mentioned elements were determined. With the results obtained, the parameters of accuracy, precision, detection limit, quantification limit and uncertainty associated with the method were determined for each

  1. Investigations into the fast ionic conductors γ-CuBr, Li2S, Na2S, Ba2NH, NaTaN2 and Li3HoCl6 by means of neutron scattering

    International Nuclear Information System (INIS)

    Altorfer, F.

    1994-01-01

    The main topic of this work was the investigation of ionic diffusion in solids by means of neutron scattering. Experiments were carried out on the antifluorites Li 2 S, Na 2 S and γ-CuBr (zinc-blende type) as well as on Barium-Nitride-Hydride Ba 2 NH, NaTaN 2 and Li 3 HoCl 6 which represent three-and two-dimensional ionic conductors, respectively. In the sulphur based antifluorites Li 2 S and Na 2 S the occupation of the interstitial empty cube site by cations occurs at elevated temperatures. The temperature-dependence of the diffusion process has been investigated by quasielastic, incoherent neutron scattering. The cations hop between their regular lattice sites and the interstitial empty cube site, whereas the sulphur ions vibrate in good approximation harmonically even at high temperatures. The jump vectors define a three-dimensional net of possible cation paths through the crystal. The analysis of quasielastic scattering experiments on a Li 2 S single crystal enabled us to determine the jump vectors and the jump rates 1/τ. The temperature dependence of the anharmonic contributions to the copper structure factor was the main point in our neutron diffraction experiments on γ-CuBr. It could be shown that the copper density function deviates strongly from the isotropic form with increasing temperature. Barium-Nitride-Hydride is one of the few documented H - -ionic conductors. The electronic part of the ds-conductivity is only 1/10000 of the ionic contribution. Since Ba 2 NH is a layer compound, where H - and N 3- layers alternate along the c-axis, the probability of jumps out of the plane is suppressed in favour of in plane jumps. This compound is therefore a model system in which two-dimensional diffusion can be studied and in fact the analysis of the quasielastic data proved that the H-diffusion is caused by jumps between regular H - lattice sites. (author) figs., tabs., refs

  2. Ionizing radiation action of transport systems of Na+ and K+ of neutronal membranes. Potassium ions reaccumulation with brain slices

    International Nuclear Information System (INIS)

    Dvoretsky, A.I.; Shainskaya, A.M.; Ananyeva, T.V.; Kulikova, I.A.

    1990-01-01

    The biological effect of ionizing radiation (IR) on the Na,K pump of the surviving brain cortex slices was investigated. It was shown that IR leads to marked disturbances in the Na,K pump activity and causes essential phasic changes in potassium ion reaccumulation by brain slices in different time after exposure. The possibility of modelling the radiation effect with the help of phospholipase A2 and decylenic acid was shown. The mechanisms of the functional disturbance of Na-K pump of nerve cells after irradiation are under discussion. (author)

  3. Neutron physics

    International Nuclear Information System (INIS)

    Beckurts, K.H.; Wirtz, K.

    1974-01-01

    This textbook consists of four sections which deal with the following subjects: 1. Production of neutrons and their interactions with the nuclei; neutron sources; neutron detectors; cross-section measurements. 2. Theory of neutron interactions with macroscopic media; neutron slowing down; space distribution of moderated neutrons; neutron thermalization; neutron scattering. 3. Radioactive probe measurements of thermal neutron fluxes; activation by means of epithermal neutrons; threshold detectors of fast neutrons; neutron calibration. 4. Neutron energy; slowing down kernels; neutron age; diffusion length and absorption of neutrons

  4. Structure of AgxNa1-xPO3 glasses by neutron diffraction and reverse Monte Carlo modelling

    International Nuclear Information System (INIS)

    Hall, Andreas; Swenson, Jan; Karlsson, Christian; Adams, Stefan; Bowron, Daniel T

    2007-01-01

    We have performed structural studies of mixed mobile ion phosphate glasses Ag x Na 1-x PO 3 using diffraction experiments and reverse Monte Carlo simulations. This glass system is particularly interesting as a model system for investigations of the mixed mobile ion effect, due to its anomalously low magnitude in the system. As for previously studied mixed alkali phosphate glasses, with a much more pronounced mixed mobile ion effect, we find no substantial structural alterations of the phosphorous-oxygen network and the local coordination of the mobile cations. Furthermore, the mobile Ag + and Na + ions are randomly mixed with no detectable preference for either similar or dissimilar pairs of cations. However, in contrast to mixed mobile ion systems with a very pronounced mixed mobile ion effect, the two types of mobile ions have, in this case, very similar local environments. For all the studied glass compositions the average Ag-O and Na-O distances in the first coordination shell are determined to be 2.5 ± 0.1 and 2.5 ± 0.1 A, and the corresponding average coordination numbers are approximately 3.2 and 3.7, respectively. The similar local coordinations of the two types of mobile ions suggests that the energy mismatch for a Na + ion to occupy a site that previously has been occupied by a Ag + ion (and vice versa) is low, and that this low energy mismatch is responsible for the anomalously weak mixed mobile ion effect

  5. Absolute measurement of the cross sections of neutron radiative capture for 23Na, Cr, 55Mn, Fe, Ni, 103Rh, Ta, 197Au and 238U in the 10-600keV energy range

    International Nuclear Information System (INIS)

    Le Rigoleur, Claude; Arnaud, Andre; Taste, Jean.

    1976-10-01

    The total energy weighting technique has been applied to measuring absolute neutron capture cross sections for 23 Na, Cr, 55 Mn, Fe, Ni, 103 Rh, Ta, 197 Au, 238 U in the 10-600keV energy range. A non hydrogeneous liquid scintillator was used to detect the gamma from the cascade. The neutron flux was measured with a 10 B INa(Tl) detector or a 6 Li glass scintillator of well known efficiency. The fast time-of-flight technique was used with on line digital computer data processing [fr

  6. Illuminance and global solar irradiation in Northeast Brazil; Iluminancia e irradiacao solar global na regiao Nordeste do Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Sergio da S.; Tiba, Chigueru [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear], Emails: tiba@ufpe.br, chigueru.tiba@pesquisador.cnpq.br

    2006-07-01

    In Brazil and particularly in the Northeast of Brazil, illuminance measures are not part of routine meteorological station measures, and therefore they are still rare than solar irradiation measures. In this context, two stations were installed in Pernambuco: one in Recife (maritime tropical climate) in April 2003 and the other in Pesqueira (tropical and semi-arid) in September 2004 for carrying out simultaneous measurements of hourly solar irradiation and illuminance which permit the modeling and the statistic validation of the relationship between these two parameters and with this, makes possible the estimation of illuminance where there existed only information on solar irradiation. The Alados et al. model with local coefficients showed a superior statistical performance, producing a mean bias deviation in the order of 3% and 1% and root mean quadratic deviation of 10% and 3% respectively for Recife and Pesqueira (author)

  7. The First Test of the New Neutron Generator at the Všb / Technical University of Ostrava První Test Nového Neutronového Generátoru Na Všb-Tu Ostrava

    Directory of Open Access Journals (Sweden)

    Alexa Petr

    2013-09-01

    Full Text Available Kompaktní neutronový generátor MP320 (Thermo Scientific Inc. pracující na principu deuterium-tritiové reakce byl testován před plánovaným využitím jako zdroj neutronů pro neutronovou aktivační analýzu pomocí rychlých neutronů. Destičky vyrobené z Al, Fe, Sn a Si byly ozářeny svazkem neutronů s energií 14 MeV a byly identifikovány reakce indukované neutrony typické pro uvedené prvky.

  8. Determination of Cl, K, Mg, Mn, Na and V in Brazilian red wine by neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Daniele, Anna Paula; Maihara, Vera Akiko, E-mail: annapaula@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Several studies have been carried out for determining essential elements in foodstuffs due to important nutritional role in human body functions. Such information is crucial to any intervention in the diet of a population, thus becoming representative in the public health field. Trace elements are good indicators of wine’s origin and their concentrations can be used as criteria to ensure authenticity, quality and show that the tolerance limits established by law were respected throughout the production process. Although Brazilian wine industry is among the 15 largest in the world, analytical studies on the content of organic and inorganic compounds in wine are still small compared to other major producers. This study aimed to evaluate the elemental concentration of Cl, K, Mg, Mn, Na and V in seven national red wine samples acquired in the markets of Sao Paulo city. The analytical method applied was INAA. Concentrations of the elements in wine samples showed high variation among samples. (author)

  9. Determination of Cl, K, Mg, Mn, Na and V in Brazilian red wine by neutron activation analysis

    International Nuclear Information System (INIS)

    Daniele, Anna Paula; Maihara, Vera Akiko

    2015-01-01

    Several studies have been carried out for determining essential elements in foodstuffs due to important nutritional role in human body functions. Such information is crucial to any intervention in the diet of a population, thus becoming representative in the public health field. Trace elements are good indicators of wine’s origin and their concentrations can be used as criteria to ensure authenticity, quality and show that the tolerance limits established by law were respected throughout the production process. Although Brazilian wine industry is among the 15 largest in the world, analytical studies on the content of organic and inorganic compounds in wine are still small compared to other major producers. This study aimed to evaluate the elemental concentration of Cl, K, Mg, Mn, Na and V in seven national red wine samples acquired in the markets of Sao Paulo city. The analytical method applied was INAA. Concentrations of the elements in wine samples showed high variation among samples. (author)

  10. Neutron field characterization in the installation for BNCT study in the IEA-R1 reactor; Caracterizacao do campo de neutrons na instalacao para estudo em BNCT no reator IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro Junior, Valdeci

    2008-07-01

    This work aims to characterize the mixed neutron and gamma field, in the sample irradiation position, in a research installation for Boron Neutron Capture Therapy (BNCT), in the IPEN IEA-R1 reactor. The BNCT technique has been studied as a safe and selective option in the treatment of resistant cancerigenous tumors or considered non-curable by the conventional techniques, for example, the Glioblastoma Multiform - a brain cancerigenous tumor. Neutron flux measurements were carried out: thermal, resonance and fast, as well as neutron and gamma rays doses, in the sample position, using activation foils detectors and thermoluminescent dosimeters. For the determination of the neutron spectrum and intensity, a set of different threshold activation foils and gold foils covered and uncovered with cadmium irradiated in the installation was used, analyzed by a high Pure Germanium semiconductor detector, coupled to an electronic system suitable for gamma spectrometry. The results were processed with the SAND-BP code. The doses due to gamma and neutron rays were determined using thermoluminescent dosimeters TLD 400 and TLD 700 sensitive to gamma and TLD 600, sensitive to neutrons. The TLDs were selected and used for obtaining the calibration curves - dosimeter answer versus dose - from each of the TLD three types, which were necessary to calculate the doses due to neutron and gamma, in the sample position. The radiation field, in the sample irradiation position, was characterized flux for thermal neutrons of 1.39.10{sup 8} {+-} 0,12.10{sup 8} n/cm{sup 2}s the doses due to thermal neutrons are three times higher than those due to gamma radiation and confirm the reproducibility and consistency of the experimental findings obtained. Considering these results, the neutron field and gamma radiation showed to be appropriated for research in BNCT. (author)

  11. Measurement of activation cross sections of the {sup 27}Al(n,α){sup 24}Na and {sup 27}Al(n,p){sup 27}Mg reactions with quasi-monoenergetic neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Zaman, Muhammad; Kim, Guinyun; Kim, Kwangsoo [Kyungpook National Univ., Daegu (Korea, Republic of). Dept. of Physics; Naik, Haladhara [Kyungpook National Univ., Daegu (Korea, Republic of). Dept. of Physics; Bhabha Atomic Research Centre, Mumbai (India). Radiochemistry Div.; Lee, Young-Ouk; Cho, Young-Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of). Nuclear Data Center; Lee, Man Woo; Kang, Yeong-Rok [Dongnam Institute of Radiological and Medical Science, Busan (Korea, Republic of). Research Center

    2017-10-01

    The cross sections of the {sup 27}Al(n,α){sup 24}Na and {sup 27}Al(n,p){sup 27}Mg reactions with the average neutron energies of 15.2, 26.4, and 37.2 MeV were measured using the activation and off-line γ-ray spectrometric technique at the Korean Institute of Radiological and Medical Sciences (KIRAMS), Korea. Quasi-monoenergetic neutrons produced via the {sup 9}Be(p,n) reaction with the proton beam energies of 25, 35, and 45 MeV from the MC50 cyclotron of KIRAMS were used. The present measured values were compared with those from the evaluated nuclear data libraries ENDF/B-VII, TENDL-2015, TALYS 1.8, and from literature. In general, a close agreement with the literature data as well as the evaluated data was found.

  12. Instrumental neutron-activation analysis applications in the age dynamics assessment of Ca, Cl, K, Mg. Mn, Na, P, and Sr contents in the human cortical bone

    International Nuclear Information System (INIS)

    Zaichick, V.

    2003-01-01

    Full text: Senile osteoporosis and particularly osteoporosis among postmenopausal women represents an urgent problem of modern medicine. One of the main osteoporosis symptoms is a decrease in both bone mineral density and subsequent bone strength. The upper extremity of the femur in humans is a particularly vulnerable section of the skeleton, being subject to fracture and necrosis and to destruction of its cartilage. Iliac crest biopsies are commonly taken clinically on patients. It is known that the control of the mineral component providing bone strength is a good indicator to detect bone diseases like osteoporosis. Despite this, changes of chemical element contents occurring with age in the femoral head and the iliac crest of female and male separately have been little studied, but in iliac cortical bone have not been studied at all. The effect of age and sex on chemical element contents in intact cortical bone of femoral neck and iliac crest of 81 relatively healthy 15-55 years old women (n=36) and men (n=45) was investigated. All subjects had died suddenly and bone samples were obtained at necropsy from the right side of bodies within twenty-four hours after death. A tool made of titanium and plastic was used to clear samples from soft tissues and blood and to cut cortical part of bone. The IAEA and NIST reference materials (H-5 animal bone and SRM1486 bone meal) were used to estimate the precision and accuracy of results. Contents of Ca, Cl, K, Mg> Mn, Na, P, and Sr in intact bone samples were determined by instrumental neutron activation analysis using short-lived radionuclides. Our means data for each element of reference materials were within the certified 95 % confidence interval, and indicate an acceptable accuracy of the obtained results. No age- and sex-related differences in the cortical femoral neck composition were detected. Mean values (M±S.E.M.) of Ca, Cl, K, Mg, Mn, Na, P, and Sr mass fractions (on dry weight basis) for female and male all

  13. Fatores determinantes da mortalidade neonatal em um municipio da Regiao Sul do Brasil

    Directory of Open Access Journals (Sweden)

    Rosangela Aparecida Pimenta Ferrari

    2013-06-01

    Full Text Available Pesquisa quantitativa do tipo ecológico cujo objetivo foi identificar os fatores de risco que determinaram o óbito neonatal no município de Londrina, Paraná, entre 2000 e 2009. Verificou-se que idade materna, escolaridade, renda familiar, ocupação, situação conjugal, tipo de parto e número de consultas pré-natais não se associaram ao óbito neonatal. Entretanto, o peso ao nascer, a idade gestacional, o índice de Apgar no 1º e 5º minutos e local do parto mostraram-se estatisticamente significativos. Mais de 73,0% dos recém-nascidos evoluíram para óbito no período neonatal precoce. A causa básica predominante foi a afecção perinatal (77,7%, sendo que 72,6% das mortes foram consideradas evitáveis e a maioria, reduzível por controle adequado da gravidez e do parto. Tais resultados reforçam a necessidade de investimentos na prevenção do parto prematuro com assistência antenatal e ao parto equitativa, acessível e integral entre os diferentes níveis de atenção à saúde materno-infantil.

  14. Dosimetric evaluation of the Fricke gel dosimeter using the spectrophotometric technique for application in electron and neutron dosimetry; Avaliacao dosimetrica da solucao Fricke gel usando a tecnica de espectrofotometria para aplicacao na dosimetria de eletrons e neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Mangueira, Thyago Fressatti [Instituto de Pesquisas Energeticas e Nucleares (GMR/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Metrologia das Radiacoes

    2011-07-01

    The main dosimetric characteristics of the Fricke Xylenol Gel (FXG) solution were established for further application in the measurement of dose distribution of clinical electron fields. The dose-response curves of the FXG in a thermal neutron field were also evaluated for application in Boron Neutron Capture Therapy (BNCT) and industrial electron fields. The standard reading technique was the spectrophotometry. For clinical fields the intra and inter-batch reproducibility of FXG solution are better than 1.4% and 5.1%, respectively. The optical response presents a linear behavior for doses ranging from 0.2 to 40 Gy independently of the electron energy and the dose rate in the studied ranges. Due to the effects of the FXG natural oxidation, the optimum elapsed time between FXG preparation and irradiation was established as 24h. The behavior of the dose-response curve does not change the obtained absorbance values relative to the non-irradiated dosimeter response during the studied period. The dose-response curve to industrial electron beam presented an exponential decreasing behavior. The optical response to thermal neutrons beam presented a linear behavior for the studied dose range. According to the obtained results to the different radiation fields studied it was not observed changes in the wavelength of the typical bands of the absorption spectrum radiation induced. Additional tests were performed with FXG solution to verify the viability and application of FXG dosimetry on intracavitary brachytherapy using digital photographic imaging. The excellent performance of the FXG dosimeter indicates that this dosimeter may be applied to tri-dimensional dose evaluation in radiotherapy treatments using electrons and neutron beams. (author)

  15. Dosimetric evaluation of the Fricke gel dosimeter using the spectrophotometric technique for application in electron and neutron dosimetry; Avaliacao dosimetrica da solucao Fricke gel usando a tecnica de espectrofotometria para aplicacao na dosimentria de eletrons e neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Mangueira, Thyago Fressatti

    2009-07-01

    In this work the main dosimetric characteristics of the Fricke Xylenol Gel (FXG) solution were established for further application in the measurement of dose distribution of clinical electron fields. The dose-response curves of the FXG in a neutron field were also evaluated for the research in Boron Neutron Capture Therapy (BNCT) and industrial electron fields. The standard reading technique was the spectrophotometric. For the clinical field, the intra and inter-batch reproducibility are better than 1.4% and 5.1 %, respectively, the response presents a linear behavior for doses ranging from 0.2 to 40 Gy independently of the energy and the dose rate in the studied ranges. Due to the effects of the FXG natural oxidation, the optimum elapsed time between FXG preparation and irradiation was established as 24h period and the behavior of the dose-response curve of the FXG using the variation in the absorbance relative to the non-irradiated dosimeter as a basis during the whole studied period were not altered. The dose-response to the industrial electron beam presented an exponential decreasing behavior and the neutron beam for research in BNCT presented a linear behavior for the complete studied dose range. According to the obtained results for the different types of radiation studied for the FXG, there was no change in the position of the characteristic bands of the absorption spectrum due to the interaction of these radiation types. Additional tests were performed to determine the digital photographic imaging of FXG analyses viability and the application of FXG dosimetry on intracavitary brachytherapy. The good performance of the FXG dosimeter in the tests that were carried out indicates that this dosimeter may be applied to the tri-dimensional dose evaluation in radiotherapic treatments using electrons and neutron beams. (author)

  16. Determination of Ca, Cr, Cu, Fe, K, Mg, Na and Zn in Brazilian medicinal plants by neutron activation and atomic absorption; Determinacao de Ca, Cr, Cu, Fe, K, Mg, Na e Zn em plantas medicinais brasileiras por ativacao neutronica e absorcao atomica

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Ricardo P. de; Sabino, Claudia de Vilhena S.; Franco, Milton B.; Amaral, Angela M.; Guedes, Joao B.; Assis, Adilson de C. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Leite, Simone C.A.L.; Silva, Isabel R. [Pontificia Univ. Catolica de Minas Gerais, Belo Horizonte, MG (Brazil)

    2002-07-01

    Medicinal plants are available in the markets in Belo Horizonte, Minas Gerais. The objective of this work is to investigate the Ca, Cr, Cu, Fe, K, Mg, Na e Zn concentrations in two lots of usually known diuretics plants (azeitona do mato, cabelo de milho, cavalinha, cervejinha do campo, chapeu de couro, congonha de bugre, marmelinho do campo and quebra pedra) bought with an interval of time - six months - between the purchases. The elemental concentrations were determined applying k{sub 0} instrumental neutron activation analysis and atomic absorption spectrophotometry analysis. (author)

  17. Neutron guide

    Science.gov (United States)

    Greene, Geoffrey L.

    1999-01-01

    A neutron guide in which lengths of cylindrical glass tubing have rectangular glass plates properly dimensioned to allow insertion into the cylindrical glass tubing so that a sealed geometrically precise polygonal cross-section is formed in the cylindrical glass tubing. The neutron guide provides easier alignment between adjacent sections than do the neutron guides of the prior art.

  18. Estimation of covariances of {sup 16}O, {sup 23}Na, Fe, {sup 235}U, {sup 238}U and {sup 239}Pu neutron nuclear data in JENDL-3.2

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, Keiichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Nakajima, Yutaka; Kawano, Toshihiko; Oh, Soo-Youl; Matsunobu, Hiroyuki; Murata, Toru

    1997-10-01

    Covariances of nuclear data have been estimated for 6 nuclides contained in JENDL-3.2. The nuclides considered are {sup 16}O, {sup 23}Na, Fe, {sup 235}U, {sup 238}U, and {sup 239}Pu, which are regarded as important for the nuclear design study of fast reactors. The physical quantities for which covariances are deduced are cross sections, resolved and unresolved resonance parameters, and the first order Legendre-polynomial coefficient for the angular distribution of elastically scattered neutrons. As for {sup 235}U, covariances were obtained also for the average number of neutrons emitted in fission. The covariances were estimated by using the same methodology that had been used in the JENDL-3.2 evaluation in order to keep a consistency between mean values and their covariances. The least-squares fitting code GMA was used in estimating covariances for reactions of which JENDL-3.2 cross sections had been evaluated by taking account of measurements. In nuclear model calculations, the covariances were calculated by the KALMAN system. The covariance data obtained were compiled in the ENDF-6 format, and will be put into the JENDL-3.2 Covariance File which is one of JENDL special purpose files. (author). 193 refs.

  19. Neutron physics

    CERN Document Server

    Reuss, Paul

    2008-01-01

    Originally just an offshoot of nuclear physics, neutron physics soon became a branch of physics in its own right. It deals with the movement of neutrons in nuclear reactors and ail the nuclear reactions they trigger there, particularly the fission of heavy nuclei which starts a chain reaction to produce energy. Neutron Physics covers the whole range of knowledge of this complex science, discussing the basics of neutron physics and some principles of neutron physics calculations. Because neutron physics is the essential part of reactor physics, it is the main subject taught to students of Nuclear Engineering. This book takes an instructional approach for that purpose. Neutron Physics is also intended for ail physicists and engineers involved in development or operational aspects of nuclear power.

  20. Neutron radiography

    International Nuclear Information System (INIS)

    Hiraoka, Eiichi

    1988-01-01

    The thermal neutron absorption coefficient is essentially different from the X-ray absorption coefficient. Each substance has a characteristic absorption coefficient regardless of its density. Neutron deams have the following features: (1) neutrons are not transmitted efficiently by low molecular weight substances, (2) they are transmitted efficiently by heavy metals, and (3) the transmittance differs among isotopes. Thus, neutron beams are suitable for cheking for foreign matters in heavy metals and testing of composites consisting of both heavy and light materials. A neutron source generates fast neutrons, which should be converted into thermal neutrons by reducing their energy. Major neutron souces include nuclear reactors, radioisotopes and particle accelerators. Photographic films and television systems are mainly used to observe neutron transmission images. Computers are employed for image processing, computerized tomography and three-dimensional analysis. The major applications of neutron radiography include inspection of neclear fuel; evaluation of material for airplane; observation of fuel in the engine and oil in the hydraulic systems in airplanes; testing of composite materials; etc. (Nogami, K.)

  1. Small-angle neutron scattering studies of sodium butyl benzene

    Indian Academy of Sciences (India)

    Na-NBBS), in aqueous solutions is investigated by small-angle neutron scattering (SANS). Nearly ellipsoidal aggregates of Na-NBBS at concentrations well above its minimum hydrotrope concentration were detected by SANS. The hydrotrope ...

  2. Small-angle neutron scattering studies of sodium butyl benzene ...

    Indian Academy of Sciences (India)

    Na-NBBS), in aqueous solutions is investigated by small-angle neutron scattering (SANS). Nearly ellipsoidal aggregates of Na-NBBS at concentrations well above its minimum hydrotrope concentration were detected by SANS. The hydrotrope ...

  3. Neutron detector

    Science.gov (United States)

    Stephan, Andrew C [Knoxville, TN; Jardret,; Vincent, D [Powell, TN

    2011-04-05

    A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

  4. Fusion neutronics

    CERN Document Server

    Wu, Yican

    2017-01-01

    This book provides a systematic and comprehensive introduction to fusion neutronics, covering all key topics from the fundamental theories and methodologies, as well as a wide range of fusion system designs and experiments. It is the first-ever book focusing on the subject of fusion neutronics research. Compared with other nuclear devices such as fission reactors and accelerators, fusion systems are normally characterized by their complex geometry and nuclear physics, which entail new challenges for neutronics such as complicated modeling, deep penetration, low simulation efficiency, multi-physics coupling, etc. The book focuses on the neutronics characteristics of fusion systems and introduces a series of theories and methodologies that were developed to address the challenges of fusion neutronics, and which have since been widely applied all over the world. Further, it introduces readers to neutronics design’s unique principles and procedures, experimental methodologies and technologies for fusion systems...

  5. The neutron

    International Nuclear Information System (INIS)

    Cheetham, A.K.

    1990-01-01

    In 1932, when Chadwick obtained the first unambiguous evidence for the existence of the neutron, his discovery confirmed the widely held belief that there existed a particle with zero charge and a mass similar to that of the proton. Indeed, as early as 1920, Lord Rutherford had suggested such a possibility in a lecture to the Royal Society. The discovery of the neutron had an immediate and dramatic impact in several areas. The nucleus, which had hitherto been regarded, somewhat unsatisfactorily, as a combination of protons and electrons, was now seen as comprising of protons and neutrons. This in turn lead to a proper understanding of the nature of isotopes and provided a fresh basis for nuclear theories. This paper examines the nature and properties of the neutron, and describes some facets of its remarkable role in contemporary science and technology. The aspects covered are its properties, the production and detection of neutrons, the reactions between neutrons and nuclei, fission reactions, neutron scattering, pulsed neutron scattering and neutron spectroscopy. (author)

  6. Atmospheric neutrons

    International Nuclear Information System (INIS)

    Preszler, A.M.; Moon, S.; White, R.S.

    1976-01-01

    Additional calibrations of the University of California double-scatter neutron and additional analysis corrections lead to the slightly changed neutron fluxes reported here. The theoretical angular distributions of Merker (1975) are in general agreement with our experimental fluxes but do not give the peaks for vertical upward and downward moving neutrons. The theoretical neutron escape current J 2 /sub pi/ (Merker, 1972; Armstrong et al., 1973) is in agreement with the experimental values from 10 to 100 MeV. Our experimental fluxes agree with those of the Kanbach et al. (1974) in the overlap region from 70 to 100 MeV

  7. Molecular aluminum hydrides identified by inelastic neutron scattering during H2 regeneration of catalyst-doped NaAlH4.

    Science.gov (United States)

    Fu, Qi Jia; Ramirez-Cuesta, A J; Tsang, Shik Chi

    2006-01-19

    Catalyst-doped sodium aluminum hydrides have been intensively studied as solid hydrogen carriers for onboard proton-exchange membrane (PEM) fuel cells. Although the importance of catalyst choice in enhancing kinetics for both hydrogen uptake and release of this hydride material has long been recognized, the nature of the active species and the mechanism of catalytic action are unclear. We have shown by inelastic neutron scattering (INS) spectroscopy that a volatile molecular aluminum hydride is formed during the early stage of H2 regeneration of a depleted, catalyst-doped sodium aluminum hydride. Computational modeling of the INS spectra suggested the formation of AlH3 and oligomers (AlH3)n (Al2H6, Al3H9, and Al4H12 clusters), which are pertinent to the mechanism of hydrogen storage. This paper demonstrates, for the first time, the existence of these volatile species.

  8. Neutron dosimetry; Dosimetria de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Fratin, Luciano

    1993-12-31

    A neutron irradiation facility was designed and built in order to establish a procedure for calibrating neutron monitors and dosemeters. A 185 GBq {sup 241} Am Be source of known is used as a reference source. The irradiation facility using this source in the air provides neutron dose rates between 9 nSv s{sup -1} and 0,5 {sup {mu}}Sv s{sup -1}. A calibrated 50 nSv s{sup -1} thermal neutron field is obtained by using a specially designed paraffin block in conjunction with the {sup 241} Am Be source. A Bonner multisphere spectrometer was calibrated, using a procedure based on three methods proposed by international standards. The unfold {sup 241} Am Be neutron spectrum was determined from the Bonner spheres data and resulted in a good agreement with expected values for fluence rate, dose rate and mean energy. A dosimetric system based on the electrochemical etching of CR-39 was developed for personal dosimetry. The dosemeter badge using a (n,{alpha}) converter, the etching chamber and high frequency power supply were designed and built specially for this project. The electrochemical etching (ECE) parameters used were: a 6N KOH solution, 59 deg C, 20 kV{sub pp} cm{sup -1}, 2,0 kHz, 3 hours of ECE for thermal and intermediate neutrons and 6 hours for fast neutrons. The calibration factors for thermal, intermediate and fast neutrons were determined for this personal dosemeter. The sensitivities determined for the developed dosimetric system were (1,46{+-} 0,09) 10{sup 4} tracks cm{sup -2} mSv{sup -1} for thermal neutrons, (9{+-}3) 10{sup 2} tracks cm{sup -2} mSV{sup -1} for intermediate neutrons and (26{+-}4) tracks cm{sup -2} mSv{sup -1} for fast neutrons. The lower and upper limits of detection were respectively 0,002 mSv and 0,6 mSv for thermal neutrons, 0,04 mSv and 8 mSv for intermediate neutrons and 1 mSv and 12 mSv for fast neutrons. In view of the 1990`s ICRP recommendations, it is possible to conclude that the personal dosemeter described in this work is

  9. Comparison of neutron moisture gauges with nonnuclear methods to measure field soil water status Comparação de sondas de neutrons com métodos não nucleares na estimativa da água no solo em condições de campo

    Directory of Open Access Journals (Sweden)

    C. Kirda

    1992-01-01

    campo, dependência espacial e múmero de amostras necessárias levando em conta determinado nível de significância. A variância das medidas de umidade do solo obtidas por sonda de neutrons é menor do que para a amostragem gravimétrica, que requer um número de amostras 2 a 6 vezes maior em relação à sonda de neutrons dentro de um mesmo nível de significância. A dependência espacial das medidas feitas com sondas de profundidade variou de acordo com os níveis de umidade do solo. Nenhuma dependência espacial ficou evidente para umidades menores que 0,2 cm³.cm³ (50% da saturação. Medidas com tensiômetros e blocos de resistência não manifestaram dependência espacial e, por isso, a escolha das parcelas para medida facilmente se adaptam a esquemas experimentais nos quais estes métodos podem ser utilizados. Medidas de umidade de solo obtidas por sondas de neutrons mostraram uma estabilidade temporal bem definida (isto é, os valores menor, médio e mais alto de umidade do solo ocorrem na mesma posição no campo experimental o que significa que o estado da umidade do solo de um campo relativamente grande pode ser determinado através de um número limitado de medidas. Medidas com tensiômetros e blocos de resistência são variáveis no tempo (isto é, a parcela que indica a umidade média do campo varia espacialmente no tempo devido a seus domínios de medida relativamente menores (isto é, tamanho da área que pode ser representada por uma única medida em comparação com sondas de neutrons. Por isso não é possível definir posições de medidas para tensiômetros e blocos de resistência para caracterização da umidade do solo do campo todo, da forma como foi possível para sondas de neutrons.

  10. Neutronic reactor

    International Nuclear Information System (INIS)

    Wende, C.W.J.

    1976-01-01

    A safety rod for a nuclear reactor has an inner end portion having a gamma absorption coefficient and neutron capture cross section approximately equal to those of the adjacent shield, a central portion containing materials of high neutron capture cross section and an outer end portion having a gamma absorption coefficient at least equal to that of the adjacent shield

  11. Neutron diffraction

    International Nuclear Information System (INIS)

    Bacon, G.E.

    1983-01-01

    The paper reviews neutron diffraction work from the early studies to the present-day development of the subject. Direct structural investigations were described, including chemical applications associated with single crystal techniques, and magnetic applications identified with powder techniques. The properties of the neutron beams are discussed, as well as the use of polarised beams. (UK)

  12. Neutron holography

    International Nuclear Information System (INIS)

    Beynon, T.D.

    1986-01-01

    the paper concerns neutron holography, which allows an image to be constructed of the surfaces, as well as the interiors, of objects. The technique of neutron holography and its applications are described. Present and future use of the method is briefly outlined. (U.K.)

  13. Neutron tubes

    Science.gov (United States)

    Leung, Ka-Ngo [Hercules, CA; Lou, Tak Pui [Berkeley, CA; Reijonen, Jani [Oakland, CA

    2008-03-11

    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  14. Neutron source

    Science.gov (United States)

    Cason, J.L. Jr.; Shaw, C.B.

    1975-10-21

    A neutron source which is particularly useful for neutron radiography consists of a vessel containing a moderating media of relatively low moderating ratio, a flux trap including a moderating media of relatively high moderating ratio at the center of the vessel, a shell of depleted uranium dioxide surrounding the moderating media of relatively high moderating ratio, a plurality of guide tubes each containing a movable source of neutrons surrounding the flux trap, a neutron shield surrounding one part of each guide tube, and at least one collimator extending from the flux trap to the exterior of the neutron source. The shell of depleted uranium dioxide has a window provided with depleted uranium dioxide shutters for each collimator. Reflectors are provided above and below the flux trap and on the guide tubes away from the flux trap.

  15. Neutron reflectometry

    DEFF Research Database (Denmark)

    Klösgen-Buchkremer, Beate Maria

    2014-01-01

    Neutron (and X-ray) reflectometry constitute complementary interfacially sensitive techniques that open access to studying the structure within thin films of both soft and hard condensed matter. Film thickness starts oxide surfaces on bulk substrates, proceeding to (pauci-)molecular layers and up...... to hundreds of nanometers. Thickness resolution for flat surfaces is in the range of few Ǻngstrøm, and as a peculiar benefit, the presence and properties of buried interfaces are accessible. Focus here will be on neutron reflectometry, a technique that is unique in applications involving composite organic...... films or films with magnetic properties. The reason is the peculiar property of neutron light since the mass of a neutron is close to the one of a proton, and since it bears a magnetic moment. The optical properties of matter, when interacting with neutrons, are described by a refractive index...

  16. Neutron source

    International Nuclear Information System (INIS)

    Cason, J.L. Jr.; Shaw, C.B.

    1975-01-01

    A neutron source which is particularly useful for neutron radiography consists of a vessel containing a moderating media of relatively low moderating ratio, a flux trap including a moderating media of relatively high moderating ratio at the center of the vessel, a shell of depleted uranium dioxide surrounding the moderating media of relatively high moderating ratio, a plurality of guide tubes each containing a movable source of neutrons surrounding the flux trap, a neutron shield surrounding one part of each guide tube, and at least one collimator extending from the flux trap to the exterior of the neutron source. The shell of depleted uranium dioxide has a window provided with depleted uranium dioxide shutters for each collimator. Reflectors are provided above and below the flux trap and on the guide tubes away from the flux trap

  17. Neutrons, radiation and archaeology: a multi analytical case study of incised rim tradition ceramics in Central Amazon; Neutrons, radiacao e arqueologia: estudo de caso multianalitico de ceramicas da tradicao borda incisa na Amazonia Central

    Energy Technology Data Exchange (ETDEWEB)

    Hazenfratz-Marks, Roberto

    2014-07-01

    This thesis is an interdisciplinary archaeometric study involving archaeological ceramic material from two large archaeological sites in Central Amazon, namely Lago Grande and Osvaldo, on the confluence region of Negro and Solimoes rivers. It was tested a hypothesis about the existence of an exchange network between the former inhabitants of those sites, focusing on material and/or technological exchange. That hypothesis has implications for archaeological theories of human occupation of the pre-colonial Central Amazon, which try to relativise the role of ecological difficulties of the tropical forest as a limiting factor for the emergence of social complexity in the region. The physical-chemical characterization of potsherds and clay samples near the sites was carried out by: instrumental neutron activation analysis (INAA) to determine the elemental chemical composition; electron paramagnetic resonance (EPR) to determine the firing temperature; X-ray diffraction (XRD) to determine the mineralogical composition; and dating by optically stimulated luminescence (OSL). Previous studies showed that Osvaldo and Lago Grande were occupied by people which produced pottery classified in the Manacapuru and Paredao phases, subclasses of the Incised Rim Tradition, around the 5-10th and 7-12th centuries BC, respectively. INAA results were analyzed by multivariate statistical methods, whereby two chemical groups of pottery were defined for each archaeological site. Significant variation in firing temperatures and mineralogical composition were not identified for such groups. By integration of the results with archaeological data, the superposition between pairs of chemical groups was interpreted as a correlate of an ancient exchange network, although it was not possible to define if it existed exclusively between Lago Grande and Osvaldo. On the contrary, it was suggested that Lago Grande participated in a more extensive exchange network by comparison of two chemical groups

  18. A study of neutron doses in water and sea water

    International Nuclear Information System (INIS)

    Abou-Taleb, W.M.; Abou El-Khier, A.A.; Fawzy Salem, M.A.; Gaber, M.; El-Khatib, A.M.

    1988-01-01

    Experimental measurements have been carried out to determine the neutron flux from a compact D-T neutron generator in tissue equivalent mediums like water and sea water, and NaCl. The measurements were performed by using neutron activation foils as neutron detectors of successive threshold energies. The flux-dose conversion factors, as well as related quality factors averaged over the selected energy ranges, were used to determine equivalent dose and adsorbed dose rates, respectively. The experimental and calculated results were found to be in a good agreement. Besides, dose buildup factors were determined. The contribution of thermal and intermediate neutron dose is relatively lower than that for fast neutrons. (author)

  19. Neutron dosimetry in boron neutron capture therapy

    International Nuclear Information System (INIS)

    Fairchild, R.G.; Miola, U.J.; Ettinger, K.V.

    1981-01-01

    The recent development of various borated compounds and the utilization of one of these (Na 2 B 12 H 11 SH) to treat brain tumors in clinical studies in Japan has renewed interest in neutron capture therapy. In these procedures thermal neutrons interact with 10 B in boron containing cells through the 10 B(n,α) 7 Li reaction producing charged particles with a maximum range of approx. 10μm in tissue. Borated analogs of chlorpromazine, porphyrin, thiouracil and deoxyuridine promise improved tumor uptake and blood clearance. The therapy beam from the Medical Research Reactor in Brookhaven contains neutrons from a modified and filtered fission spectrum and dosimetric consequences of the use of the above mentioned compounds in conjunction with thermal and epithermal fluxes are discussed in the paper. One of the important problems of radiation dosimetry in capture therapy is determination of the flux profile and, hence, the dose profile in the brain. This has been achieved by constructing a brain phantom made of TE plastic. The lyoluminescence technique provides a convenient way of monitoring the neutron flux distributions; the detectors for this purpose utilize 6 Li and 10 B compounds. Such compounds have been synthesized specially for the purpose of dosimetry of thermal and epithermal beams. In addition, standard lyoluminescent phosphors, like glutamine, could be used to determine the collisional component of the dose as well as the contribution of the 14 N(n,p) 14 C reaction. Measurements of thermal flux were compared with calculations and with measurements done with activation foils

  20. Characterization of Pb-Free KNbO3- and (Na,BiTiO3-Based Piezoelectric Single-Crystals Using X-ray and Neutron Diffraction

    Directory of Open Access Journals (Sweden)

    Abhijit Pramanick

    2018-01-01

    Full Text Available In view of serious environmental concerns with traditional Pb-based piezoelectrics, the search for new Pb-free alternatives has intensified recently. A thorough investigation of structure-property relationships in Pb-free piezoelectrics is desired in order to design new material compositions with high electromechanical properties that can be operated over a broader range of conditions. Recent availability of high-quality single crystals has not only opened the possibility for achieving multifold enhancements in the electromechanical properties in this new class of materials, but has also provided opportunities to undertake fundamental studies on their structure-property relationships. In the following pages, I review some of the recent X-ray and neutron diffraction studies of Pb-free piezoelectric single crystals, which have provided novel insights into their multiscale stimuli-induced structural mechanisms, including phase transitions, nanoscale structural ordering, lattice instability, and domain re-orientation. Opportunities and challenges for future progress in this area of study are discussed.

  1. Neutron diffraction

    International Nuclear Information System (INIS)

    James, M.; Howard, C.J.; Kennedy, S.

    1999-01-01

    Diffraction methods, especially X-ray diffraction, are widely used in materials science. Neutron diffraction is in many ways similar to X-ray diffraction, but is also complementary to the X-ray technique so that in some cases it yields information not accessible using X-rays. Successes of neutron diffraction include the elucidation of the crystal structures of high temperature superconductors and materials that display colossal magnetoresistance, the phase analysis of zirconia engineering ceramics, in depth stress determination in composites, successful determination of the structures of metal hydrides, transition metal polymer complexes and the determination of magnetic structure. A brief description of current studies, using neutron diffraction is given

  2. Radiometer evaluation of X-rays equipment in the region of Aracatuba, Sao Paulo, Brazil;Avaliacao radiometrica de raios-X na regiao de Aracatuba, Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Marco A.R. [UNESP, Botucatu, SP (Brazil). Faculdade de Medicina; Kanezawa, Jorge S. [Centro de Ensino e Tecnologia de Aracatuba (CETEA), SP (Brazil)

    2009-07-01

    This paper presents the basic concepts of radiation protection to guide the health care professionals who use equipment emitting ionizing radiation on the correct handling of the beams of radiation. Radiometric evaluations were conducted in 1665 in X-ray equipment, installed in dental surgeries and clinics, hospitals and radiology services, during the years 1996 to 2003 in the region of Aracatuba. Tests of radiometry are presented as a technical report where the parameters are quantified physical and radiological verifying its compliance with the established by legislation. The distribution of reports by type of unit shows that the vast majority of equipment is of periapical dental x-rays (72%), 25% of equipment is medical equipment for radiology and 3% is dental equipment panoramic model (orthodontic documentation). Among the physical parameters analyzed, the length of the browser was showing more variance compared to the required by law, this fact may also contribute to gaps in the rate of the radiation dose and the size of field in the skin of the patient, the that can easily be resolved simply to replace the piece at the outlet of the head. During the completion of visits to services, it also noted a gap in the training of professionals who operate this equipment emitting radiation, warning of the need for specific training in the area. (author)

  3. Solar photovoltaic electrification in the Alto Rio Solimoes, State of Amazonas, Brazil; Energizacao solar fotovoltaica na regiao do alto Rio Solimoes no Estado do Amazonas, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Carlos Alexandre dos Santos [Amazonas Univ., Manaus (Brazil). Nucleo de Eficiencia Energetica]. E-mail: nefen_ua@objetivomao.br

    2000-07-01

    This work presents preliminary results of the project entitled 'Solar Photovoltaic Electrification of Four Isolated Communities in the Area of High Solimoes', financed by the Ministry of Science and Technology/CNPq through the Humid Tropical Program. The following aspects are highlighted in this work: the strategy of implementation of solar electrification that allowed to know the socio-cultural mechanisms of the community avoiding the rejection of the technology and the smallest alteration of the traditional processes of work; the contribution of the technologies in the process of the community's organization and also for the development of this; the process of domain of the technological knowledge from the part of the community; the economic comparison between the electrification with photovoltaic systems and gasoline electric generators in schools and community centers and the problems verified for the use, administration and diffusion of photovoltaic systems. (author)

  4. Analysis of the natural gas market in Fortaleza metropolitan region (Brazil); Analise do mercado de gas natural na regiao metropolitana de Fortaleza

    Energy Technology Data Exchange (ETDEWEB)

    Barroso, Carlos Andre M.; Rabelo, Clarice A.C.; Santana, Lana L.P.; Sucupira, Marcos L.L. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil)

    2004-07-01

    Natural gas has become one of the most important energy sources, as we can observe in most countries' energy sector, where its presence is very significant. In Brazil, natural gas corresponds to 7,5% of all energy Also available, and the government has plans to increase this number to 12% until 2010. However, in order to reach this goal, it is important to understand how market works, evaluating all the aspects that have some influence on it. This paper goal is to analyze the natural gas market in Fortaleza metropolitan region, emphasizing the industrial sector, the biggest consumer in Ceara State. The main aspects are characterized here, like professionals qualification in the area, service quality, from equipment and maintenance suppliers until gas distributors, legal aspects, and other factors that are also relevant to a possible future expansion of different natural gas market segments (industry, residence, commerce and transport). (author)

  5. Biomonitoring of air quality in the metropolitan region of Recife, PE, Brazil; Biomonitoracao da qualidade do ar na Regiao Metropolitana do Recife, PE

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Thiago Oliveira dos

    2016-08-01

    The interest on questions related to environmental conservation has increased in recent decades, being air pollution one of the main public health problems in huge urban centers. Major part of this atmospheric contamination is caused by gaseous pollutants and inhalable particulate matter. One of the main sources is the burning of fossil fuels mainly emitted by motor vehicles. Some organisms, like lichen and atmospheric bromeliad, are able to accumulate chemical elements in their tissues, thereby becoming excellent tools for air quality studies of monitoring. The present work evaluated the air quality in the Metropolitan Region of Recife (RMR) using the lichen Cladonia verticillaris and the bromeliad Tillandsia recurvata, through the quantification of chemical elements associated to vehicles traffic. The biomonitors were transferred to 40 points distributed in the RMR with different intensities of the vehicle traffic. After the exposition period of six months, Al, Ba, Ca, Cd, Cl, Fe, Mg, Mn, P, Pb, Sb, Sr, Th, V and Zn were quantified by Energy Dispersive X-Ray Fluorescence (EDXRF) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The organisms were complementary, being appropriated tools for monitoring the air quality. The vehicle traffic was considered one of the major contributor for increasing chemical elements in the RMR urban atmosphere. (author)

  6. Determination of the crust thickness in the active margin of the Antarctic region; Determinacao da estrutura crustal na margem ativa da regiao antartica

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Luiz Carlos; Gamboa, Luiz Antonio Pierantoni [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Lagemar; Gomes, Benedito Souza [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    1997-07-01

    Seismic multichannel, gravity and magnetometry measurements were carried out in the region of West coast of the Antarctic Peninsula, Bransfield Strait, South Shetland Islands and South Shetland Trench, by Brazilian Antarctic Program during the summers of 1987 and 1988. The present work, using a continue seismic and gravity and gravity data profile crossing the area, intends to present a two-dimensional model of the crust thickness in this region. By this model, the Moho discontinuity would lie at a depth of 14.5 km below the axis of the Bransfield trough. This anomalous behaviour in addition to compressional processes identified in the accretionary prism and trench, was interpreted as an evidence of the continued opening of the Bransfield basin. (author)

  7. Economic and financial evaluation of the wind power project in Northeast region, Brazil; Avaliacao economico-financeira de projeto de central eolica na regiao nordeste

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Paulo Glicio da; Lima, Maria Angela de Queiroz; Melo Junior, Adalberto de Bastos [Companhia Hidro Eletrica do Sao Francisco (DFPL/CHESF), Recife, PE (Brazil). Div. de Planejamento Economico-Financeiro], Emails: paulogr@chesf.gov.br, angelq@chesf.gov.br, adalbert@chesf.gov.br; Bezerra, Pedro; Bittencourt, Rogerio [Companhia Hidro Eletrica do Sao Francisco (DEFA/CHESF), Recife, PE (Brazil). Div. de Projetos de Fontes Alternativas], E-mails: pbezerra@chesf.gov.br, rogeriob@chesf.gov.br

    2000-07-01

    This work deals with the analysis of economic and financial feasibility of using wind power in the Northeast region for electric power production, considering the new electricity sector model. The case study presented here refers to the design of a 50 MW Wind Farm in the region, based on preliminary data from wind collected in the period from 1993 to 1995. Some programs were used to evaluate this project: ALWIN, which estimates the potential for wind energy production; NEWAVE for determination operating marginal costs and generation plants values and ANAFIN, for economic and financial evaluation of the project, using scenarios, through the deterministic and probabilistic analysis.

  8. Extraskeletal osteosarcoma in the neck. A case report and review of the literature; Osteosarcoma extra-esqueletico na regiao cervical. Revisao de literatura e relato de caso clinico

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Jose Jorge Gomes; Silva, Fabio Luis da [Santa Casa de Misericordia, Piracicaba, SP (Brazil). Centro de Tomografia Computadorizada; Manzi, Flavio Ricardo [Pontificia Univ. Catolica de Minas Gerais, Belo Horizonte, MG (Brazil). Radiologia Odontologica]. E-mail: flaviomanzi@hotmail.com; Baptista, Mauricio Zuccollotto [Santa Casa de Misericordia, Piracicaba, SP (Brazil). Inst. de Oncologia Clinica

    2002-10-01

    Extra skeletal osteosarcoma is a rare neoplasm characterized by the formation of a malignant osteoid. This condition is usually described in patients aged greater than expected for other intraosseous osteosarcomas, and the thigh is the most common site. We report a clinical case of a 19-year-old female patient and review the literature. The patient present with a mass in the right side of the neck and paraesthesia of the upper limbs. The mass corresponded to an extraskeletal osteosarcoma. We discuss the clinical findings, image findings (conventional radiographs, computed tomography, magnetic resonance imaging), histopathology results and differential diagnosis of this condition. (author)

  9. Polyphenol oxidase and peroxidase in different sugarcane cultivars, in Presidente Prudente region; Polifenoloxidases e peroxidase em diferentes variedades de cana-de-acucar na regiao de Presidente Prudente

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Tadeu A.; Gomes, Danilo B.; Marques, Patricia A.A.; Alves, Vagner C. [Universidade do Oeste Paulista (UNOESTE), Presidente Prudente, SP (Brazil). Curso de Agronomia], Emails: tmarques@unoeste.br, pmarques@unoeste.br, vagner@unoeste.br

    2009-07-01

    The objective in present work was compare three sugarcane cultivars (RB 72-454, RB 86-7515, IAC 86-2480), evaluating the content of polyphenoloxidase and peroxidase. These determinations had aimed at to detect possible differences between varieties thus and being to differentiate them with regard to the products most interesting to be elaborated, ethanol production or sugar production. The varieties had presented differences of behavior for studied enzymes. The activity of polyphenoloxidase was superior the activity of peroxidase. The enzyme peroxidase was presented in bigger indices in the dry and cold periods. The enzyme polyphenoloxidase was presented well changeable, but with strong trend of bigger values in the rainy periods. It can be said that distinct periods for the best use of the varieties in the sugar production or alcohol exist. (author)

  10. The problem of gravity field representation in the Amazon region: alternatives evaluation; O problema da representacao do campo de gravidade na regiao amazonica

    Energy Technology Data Exchange (ETDEWEB)

    Sa, Nelsi Cogo de [Sao Paulo Univ., SP (Brazil). Inst. Astronomico e Geofisico. Dept. de Geofisica

    1997-07-01

    The Amazonic region is a large segment of South American Plate which contains important geologic and tectonic units, among them, the sedimentary basins: Acre, Parecis-Alto Xingu, Alto Tapajos, Amazonas, Marajo and Boa Vista; and the cratons Rio Branco and Amazonas. Although there are very interesting geophysical investigations in this region, besides its potentialities in oil and mineral prospecting, a very little was done about the regional geophysical survey. Because of the large extension and the geographical peculiarities of this region, the basic geophysical surveys have not been done yet. Today, the aerogeophysical surveys and the geophysical satellite missions are beginning a new phase in collecting data of the gravity and magnetic field of the Earth. The analysis of the existing alternatives for the representation of the gravity field in the Amazonic region, presented in this paper, suggest a combined solution of satellite gradiometry and airborne gravimetry. (author)

  11. Wind energy as alternative to isolated communities in Northern Brazil; A energia eolica como alternativa para comunidades isoladas na regiao Norte do Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Santos, W.F.; Zukowski Junior, J.C.; Nobrega, S.L. de; Marcon, R.O. [Universidade Luterana do Brasil (CEULP/ULBRA), Palmas, TO (Brazil). Centro Universitario Luterano de Palmas. Curso de Engenharia Agricola], Emails: zukowski@uft.edu.br, olavo@ulbra-to.br, silvestre@ulbra-to.br

    2009-07-01

    Bring energy to isolated communities is not easy. Among the possibilities there are the sizes of small wind systems. Within the government policy to serve the isolated communities and maroon many alternatives are being tested. The use of wind power in places where there is availability of wind is a very attractive alternative. This paper presents a small central generation of hydropower and solar wind, installed in the Boa Esperanca community, with maximum capacity to generate 3kW. The system consists of three turbines of domestic manufacturing, which generate at 48 V. The energy is used in the 'Community Workshop'. The energy in the workshop is available in 220V. The partial results show that the system can be technically and economically viable, or sustainable, provided there is the involvement of the community as a whole in the proper use of energy, maintenance and operation of micro-central generation. (author)

  12. Suggestions to leak prevention in Fortaleza's natural gas piping system; Sugestoes para a prevencao de vazamentos de gas natural canalizado na regiao metropolitana de Fortaleza

    Energy Technology Data Exchange (ETDEWEB)

    Teles, Marcus de Barros [Agencia Reguladora de Servicos Publicos Delegados do Estado do Ceara (ARCE), Fortaleza, CE (Brazil)

    2004-07-01

    Leaks are the bigger problem in health, safety and environmental when the subject is gas distribution piping systems. Specially in high density human regions, like in the majority districts of Fortaleza, safety have to be the higher priority to the gas company responsible for the gas distribution piping systems. Leaks are able to cause accidents or incidents, depending on the circumstances which they happen. In order to be control the situation and overcome the luck factor, leaks must be previously avoided by the application of some security requirements. This paper present some suggestions to natural gas leak prevention in the Fortaleza's metropolitan region pipeline systems. First, the piping systems are analysed, observing the risk regions. Then, safety actions and basic requirements to avoid pipe corrosion are presented in order to improve safety in the gas distribution piping systems of Fortaleza's metropolitan region. (author)

  13. Neutron scattering

    International Nuclear Information System (INIS)

    Furrer, A.

    1993-01-01

    This report contains the text of 16 lectures given at the Summer School and the report on a panel discussion entitled ''the relative merits and complementarities of x-rays, synchrotron radiation, steady- and pulsed neutron sources''. figs., tabs., refs

  14. Study of the neutron-rich nuclei with N=21, sup 3 sup 5 Si and sup 3 sup 3 Mg, by beta decay of sup 3 sup 5 Al and sup 3 sup 3 Na

    CERN Document Server

    Nummela, S; Caurier, E; Courtin, S; Dessagne, P; Holmlund, E; Jokinen, A; Knipper, A; Le Scornet, G; Mieh, C; Nowacki, F; Lyapin, L G; Oinonen, M; Poirier, E; Radivojevic, Z; Ramdhane, M; Trzaska, W H; Walter, G; Äystö, J

    2002-01-01

    The first information on the level structure of the N=21 nuclei, sup 3 sup 5 Si and sup 3 sup 3 Mg, has been obtained by the beta decay study of sup 3 sup 5 Al and sup 3 sup 3 Na, produced by fragmentation of an UC target with 1.4 GeV protons at CERN/ISOLDE. The experimental technique involved beta-gamma, beta-gamma-gamma, and beta-n-gamma coincidences, neutron spectra being obtained by time of flight measurements. Gamma detection was made either using large Ge counters or small BaF sub 2 scintillators (for lifetime measurements). In the case of the sup 3 sup 5 Al decay, (T sub 1 sub / sub 2 =41.6(2.2) ms), a simple structure has been found for the level scheme of sup 3 sup 5 Si (Z=14, N=21) which has been interpreted with the level sequence : 7/2 sup - , 3/2 sup - and 3/2 sup + corresponding respectively to the ground state and the states at 910 and 974 keV. The life-time of the 974 keV [T sub 1 sub / sub 2 =5.9(6) ns] is found consistent with the proposed level scheme and multipolarities. The investigation ...

  15. Neutron Scattering

    International Nuclear Information System (INIS)

    Fayer, Michael J.; Gee, Glendon W.

    2005-01-01

    The neutron probe is a standard tool for measuring soil water content. This article provides an overview of the underlying theory, describes the methodology for its calibration and use, discusses example applications, and identifies the safety issues. Soil water makes land-based life possible by satisfying plant water requirements, serving as a medium for nutrient movement to plant roots and nutrient cycling, and controlling the fate and transport of contaminants in the soil environment. Therefore, a successful understanding of the dynamics of plant growth, nutrient cycling, and contaminant behavior in the soil requires knowledge of the soil water content as well as its spatial and temporal variability. After more than 50 years, neutron probes remain the most reliable tool available for field monitoring of soil water content. Neutron probes provide integrated measurements over relatively large volumes of soil and, with proper access, allow for repeated sampling of the subsurface at the same locations. The limitations of neutron probes include costly and time-consuming manual operation, lack of data automation, and costly regulatory requirements. As more non-radioactive systems for soil water monitoring are developed to provide automated profiling capabilities, neutron-probe usage will likely decrease. Until then, neutron probes will continue to be a standard for reliable measurements of field water contents in soils around the globe

  16. FOREWORD: Neutron metrology Neutron metrology

    Science.gov (United States)

    Thomas, David J.; Nolte, Ralf; Gressier, Vincent

    2011-12-01

    The International Committee for Weights and Measures (CIPM) has consultative committees covering various areas of metrology. The Consultative Committee for Ionizing Radiation (CCRI) differs from the others in having three sections: Section (I) deals with radiation dosimetry, Section (II) with radionuclide metrology and Section (III) with neutron metrology. In 2003 a proposal was made to publish special issues of Metrologia covering the work of the three Sections. Section (II) was the first to complete their task, and their special issue was published in 2007, volume 44(4). This was followed in 2009 by the special issue on radiation dosimetry, volume 46(2). The present issue, volume 48(6), completes the trilogy and attempts to explain neutron metrology, the youngest of the three disciplines, the neutron only having been discovered in 1932, to a wider audience and to highlight the relevance and importance of this field. When originally approached with the idea of this special issue, Section (III) immediately saw the value of a publication specifically on neutron metrology. It is a topic area where papers tend to be scattered throughout the literature in journals covering, for example, nuclear instrumentation, radiation protection or radiation measurements in general. Review articles tend to be few. People new to the field often ask for an introduction to the various topics. There are some excellent older textbooks, but these are now becoming obsolete. More experienced workers in specific areas of neutron metrology can find it difficult to know the latest position in related areas. The papers in this issue attempt, without presenting a purely historical outline, to describe the field in a sufficiently logical way to provide the novice with a clear introduction, while being sufficiently up-to-date to provide the more experienced reader with the latest scientific developments in the different topic areas. Neutron radiation fields obviously occur throughout the nuclear

  17. Neutron diffraction

    International Nuclear Information System (INIS)

    Elcomb, M.M.

    2002-01-01

    Full text: Thermal neutrons have a particular combination of properties, which make them the probe of choice for a wide range of scattering applications. They penetrate most materials easily, the wavelength matches interatomic spacings, the energy matches the atomic vibrational energies and the magnetic moment allows them to uniquely interact with magnetic structures. Their widely varying scattering length is also used to advantage. It enables the determination of light atoms in the presence of heavy ones: hydrogen in organic molecules, and oxygen in the high Tc superconductors for example, or solving problems in alloy systems where distinction of atoms, which are neighbours in the periodic table, is required. In the 50 years since thermal neutron beams have been used for research there has been a steady increase in applications as technology has advanced. This also applies to the environments in which the materials are studied. In-situ studies at other than ambient temperatures, pressures and magnetic fields are now routine. By using multiple detector channels in powder instruments the data collection rate has increased by an order of magnitude to some extent compensating for the diffuse nature of the neutron source. The applications of neutron scattering are becoming more industrially oriented. The talk will highlight the complementarity of neutrons to other more readily available techniques, and give examples of recent research and applications. Copyright (2002) Australian X-ray Analytical Association Inc

  18. Neutron diffraction

    International Nuclear Information System (INIS)

    Howard, C.J.; Kennedy, S.J.

    1994-01-01

    A brief account is given of neutron diffraction techniques. Similarities and differences compared with the more familiar X-ray counterparts are discussed. In certain applications, neutron diffraction can be used to obtain information about materials which would be difficult or even impossible to obtain using other techniques. One spectacular success has been the elucidation, from neutron powder diffraction, of the crystal structures of high critical temperature oxide superconductors. There have been substantial contributions in other fields, and these are illustrated by Australian work. The ability of the neutron to penetrate deeply into most materials has been invoked for in-depth determination of stresses in composites and of phase composition in zirconia ceramics. The unique properties of the neutron have been successfully exploited in studies of metal hydrides, to determine where hydrogen is located, and in magnetic structure determination. There is much interest in studying materials under different conditions of temperature and pressure, and kinetic studies under such conditions are now becoming possible. The article includes information on the principles, the instrumentation with particular reference to the instruments installed around the HIFAR reactor at Lucas Heights, and methods for the interpretation of data. 59 refs., 3 tabs., 16 figs

  19. Selective assessment of the fast neutron component in mixed neutron-gamma field using TLD activation

    Energy Technology Data Exchange (ETDEWEB)

    Ranogajec-Komor, M. E-mail: marika@rudjer.irb.hr; Miljanic, S.; Blagus, S.; Knezevic, Z.Z.; Osvay, M

    2003-06-01

    Selective determination of the fast neutron component in a mixed radiation field by the TL dosimetry was studied. TL responses due to the induced radioactivity in Al{sub 2}O{sub 3}:C dosimeters via the {sup 27}Al(n,{alpha}){sup 24}Na reaction were used to measure the neutron part in a mixed 14.5 MeV neutron and gamma irradiation field. The lowest detectable neutron dose was found to be in order of 10 mSv of personal dose equivalent for Al{sub 2}O{sub 3}:C.

  20. Neutron Age Determination in Fast Reactor Materials using the Group Method

    Directory of Open Access Journals (Sweden)

    Kabanova Marina F.

    2016-01-01

    Full Text Available The article deals with the methods of identifying fast neutron age in sodium (Na and uranium-238 (238U; describes the model of advanced and effective fast neutron nuclear reactors (FN, where Na is a coolant while 238U is involved in the fuel cycle in large quantities; justifies the choice of the group method for calculating the neutron age value in the substances mentioned above that can show the accuracy of the used constants for Na and estimate various versions of multilevel description of neutron moderation in 238U – the most powerful resonance absorber of the neutron reactor active zone.

  1. Neutron radiography

    International Nuclear Information System (INIS)

    Pugliesi, R.; Freitas, A.G. de; Gammal, A.; Rizzatti, M.R.; Vercelli, P.

    1990-01-01

    The objective was to demonstrate the main characteristics of the neutron radiography technique, which has been developed in the Nuclear Physics Department of the IPEN-CNEN-SP. Its employment, in technology varies enormously and includes among others, the inspection of the hydrogen-rich substances, highly radioactive materials, etc. The indirect conversion method with Dysprosium screen was employed. The experimental arrangement used was a neutron collimator installed in the bottom of the IEA-R1 Nuclear Research Reactor pool. Several samples were analysed which were exposed in a neutron flux ∼ 10 7 n/s.cm 2 during 10 minutes. The obtained results confirm the main characteristics of this technique as well as its viability to be developed in this reactor. (author)

  2. neutron radiography

    International Nuclear Information System (INIS)

    Barton, J.P.

    1993-01-01

    Neutron radiography (or radiology) is a diverse filed that uses neutrons of various energies, subthermal, thermal, epithermal or fast in either steady state or pulsed mode to examine objects for industrial, medical, or other purposes, both microscopic and macroscopic. The applications include engineering design, biological studies, nondestructive inspection and materials evaluation. In the past decade, over 100 different centers in some 30 countries have published reports of pioneering activities using reactors, accelerators and isotopic neutron sources. While film transparency and electronic video are most common imaging methods for static or in motion objects respectively, there are other important data gathering techniques, including track etch, digital gauging and computed tomography. A survey of the world-wide progress shows the field to be gaining steadily in its diversity, its sophistication and its importance. (author)

  3. Neutron diffraction

    International Nuclear Information System (INIS)

    Heger, G.

    1996-01-01

    X-ray diffraction using conventional laboratory equipment and/or synchrotron installations is the most important method for structure analyses. The purpose of this paper is to discuss special cases, for which, in addition to this indispensable part, neutrons are required to solve structural problems. Even though the huge intensity of modern synchrotron sources allows in principle the study of magnetic X-ray scattering the investigation of magnetic structures is still one of the most important applications of neutron diffraction. (author) 15 figs., 1 tab., 10 refs

  4. Neutron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Heger, G. [Rheinisch-Westfaelische Technische Hochschule Aachen, Inst. fuer Kristallographie, Aachen (Germany)

    1996-12-31

    X-ray diffraction using conventional laboratory equipment and/or synchrotron installations is the most important method for structure analyses. The purpose of this paper is to discuss special cases, for which, in addition to this indispensable part, neutrons are required to solve structural problems. Even though the huge intensity of modern synchrotron sources allows in principle the study of magnetic X-ray scattering the investigation of magnetic structures is still one of the most important applications of neutron diffraction. (author) 15 figs., 1 tab., 10 refs.

  5. Neutronics of pulsed spallation neutron sources

    CERN Document Server

    Watanabe, N

    2003-01-01

    Various topics and issues on the neutronics of pulsed spallation neutron sources, mainly for neutron scattering experiments, are reviewed to give a wide circle of readers a better understanding of these sources in order to achieve a high neutronic performance. Starting from what neutrons are needed, what the spallation reaction is and how to produce slow-neutrons more efficiently, the outline of the target and moderator neutronics are explained. Various efforts with some new concepts or ideas have already been devoted to obtaining the highest possible slow-neutron intensity with desired pulse characteristics. This paper also reviews the recent progress of such efforts, mainly focused on moderator neutronics, since moderators are the final devices of a neutron source, which determine the source performance. Various governing parameters for neutron-pulse characteristics such as material issues, geometrical parameters (shape and dimensions), the target-moderator coupling scheme, the ortho-para-hydrogen ratio, po...

  6. Quantitative neutron radiography using neutron absorbing honeycomb

    International Nuclear Information System (INIS)

    Tamaki, Masayoshi; Oda, Masahiro; Takahashi, Kenji; Ohkubo, Kohei; Tasaka, Kanji; Tsuruno, Akira; Matsubayashi, Masahito.

    1993-01-01

    This investigation concerns quantitative neutron radiography and computed tomography by using a neutron absorbing honeycomb collimator. By setting the neutron absorbing honeycomb collimator between object and imaging system, neutrons scattered in the object were absorbed by the honeycomb material and eliminated before coming to the imaging system, but the neutrons which were transmitted the object without interaction could reach the imaging system. The image by purely transmitted neutrons gives the quantitative information. Two honeycombs were prepared with coating of boron nitride and gadolinium oxide and evaluated for the quantitative application. The relation between the neutron total cross section and the attenuation coefficient confirmed that they were in a fairly good agreement. Application to quantitative computed tomography was also successfully conducted. The new neutron radiography method using the neutron-absorbing honeycomb collimator for the elimination of the scattered neutrons improved remarkably the quantitativeness of the neutron radiography and computed tomography. (author)

  7. Neutron spectra and dosimetric features of isotopic neutron sources: a review

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas, Zac. (Mexico); Martinez O, S. A., E-mail: fermineutron@yahoo.com [Universidad Pedagogica y Tecnologica de Colombia, Grupo de Fisica Nuclear Aplicada y Simulacion, Av. Central del Norte 39-115, 150003 Tunja, Boyaca (Colombia)

    2015-10-15

    A convenient way to produce neutrons is the isotopic neutron source, where the production is through (α, n), (γ, n), and spontaneous fission reactions. Isotopic neutron sources are small, easy to handle, and have a relative low cost. On the other hand the neutron yield is small and mostly of them produces neutrons with a wide energy distribution. In this work, a review is carried out about the the main features of {sup 24}NaBe, {sup 24}NaD{sub 2}O, {sup 116}InBe, {sup 140}LaBe, {sup 238}PuLi, {sup 239}PuBe, {sup 241}AmB, {sup 241}AmBe, {sup 241}AmF, {sup 241}AmLi, {sup 242}CmBe, {sup 210}PoBe, {sup 226}RaBe, {sup 252}Cf and {sup 252}Cf/D{sub 2}O isotopic neutron source. Also, using Monte Carlo methods, the neutron spectra in 31 energy groups, the neutron mean energy; the Ambient dose equivalent, the Personal dose equivalent and the Effective dose were calculated for these isotopic neutron sources. (Author)

  8. Neutronic reactor

    International Nuclear Information System (INIS)

    Wende, C.W.J.

    1976-01-01

    The method of operating a water-cooled neutronic reactor having a graphite moderator is described which comprises flowing a gaseous mixture of carbon dioxide and helium, in which the helium comprises 40--60 volume percent of the mixture, in contact with the graphite moderator. 2 claims, 4 figures

  9. Neutronic reactor

    International Nuclear Information System (INIS)

    Carleton, J.T.

    1977-01-01

    A graphite-moderated nuclear reactor includes channels between blocks of graphite and also includes spacer blocks between adjacent channeled blocks with an axis of extension normal to that of the axis of elongation of the channeled blocks to minimize changes in the physical properties of the graphite as a result of prolonged neutron bombardment. 3 claims, 6 figures

  10. Neutron activation probe for measuring the presence of uranium in ore bodies

    International Nuclear Information System (INIS)

    Goldstein, N.P.; Smith, R.C.

    1979-01-01

    A neutron activation proble comprises a pulsed neutron source in series with a plurality of delayed neutron detectors for measuring radioactivity in a well borehole together with a NaI (Tl) counter for measuring the high energy 2.62 MeV gamma line from thorium. The neutron source emits neutrons which produce fission in uranium and thorium in the ore body and the delayed neutron detectors measure the delayed neutrons produced from such fission while the NaI (Tl) counter measures the 2.62 MeV gamma line from the undisturbed thorium in the ore body. The signal from the NaI (Tl) counter is processed and subtracted from the signal from the delayed neutron detectors with the result being indicative of the amount of uranium present in the ore body

  11. Neutron stars as cosmic neutron matter laboratories

    International Nuclear Information System (INIS)

    Pines, D.

    1986-01-01

    Recent developments which have radically changed our understanding of the dynamics of neutron star superfluids and the free precession of neutron stars are summarized, and the extent to which neutron stars are cosmic neutron matter laboratories is discussed. 17 refs., 1 tab

  12. Basic of Neutron NDA

    Energy Technology Data Exchange (ETDEWEB)

    Trahan, Alexis Chanel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-15

    The objectives of this presentation are to introduce the basic physics of neutron production, interactions and detection; identify the processes that generate neutrons; explain the most common neutron mechanism, spontaneous and induced fission and (a,n) reactions; describe the properties of neutron from different sources; recognize advantages of neutron measurements techniques; recognize common neutrons interactions; explain neutron cross section measurements; describe the fundamental of 3He detector function and designs; and differentiate between passive and active assay techniques.

  13. Digital Acquisition Development for Fast Neutron Detectors

    Science.gov (United States)

    Seagren, T.; Mosby, S.; Mona Collaboration; Lansce P-27 Team

    2015-10-01

    The use of the Modular Neutron Array (MoNA) at FRIB requires a thorough understanding of how neutrons propagate through the array. This leads to the increasing importance of accuracy in detector response simulations, particularly in the case of FRIB's higher beam energies. An upcoming experiment at the LANSCE facility at Los Alamos National Lab will benchmark neutron propagation through the MoNA array and provide a more complete validation of the simulation software. LANSCE also hosts the Chi-Nu experiment, which seeks to measure fission output neutrons using the high-intensity neutron beams there. In both experiments, the instantaneous rate on the detectors involved is expected to be very high, due to the LANSCE/WNR beam structure. Therefore, waveform digitizers with on-board processing are required in order for the experiments to succeed. These digitizers provide on-board timing algorithms using FPGA firmware, and several tests were preformed in order to determine what the optimal timing filter settings were for a variety of detectors, including the plastic and liquid scintillators to be used in MoNA and Chi-Nu respectively. This work will inform the execution of the MoNA and Chi-Nu experiments at LANSCE. The details of the methods used and results will be presented. Supported by funding through Los Alamos National Lab and NSF Grant PHY-1506402.

  14. Fast neutron radiography using photoluminescent imaging plates

    International Nuclear Information System (INIS)

    Rant, J.; Kristof, E.; Balasko, M.; Stade, J.

    1999-01-01

    Fast neutron radiography (FNR) and resonance neutron radiography (RNR) are complementary to the conventional radiography with high energy gamma-rays or brems-strahlung radiation used for the inspection of thick metal objects. In both non-destructive methods, the contrast sensitivity and the penetration power can be improved by using higher energy neutrons. At present direct techniques based either n Solid State Nuclear Track detectors (SSNTDs) or scintillating screens and transfer techniques using activation threshold detectors and radiographic films are applied for the detection of fast neutron images. Rather low detection sensitivity of film and SSNTD based fast neutron imaging methods and also rather poor inherent image contrast of SSNTD pose a problem for FNR in the fast neutron energy region 1-15 MeV interesting for NDT. For more efficient detection of fast neutron images the use of novel highly sensitive photoluminescent imaging plates (IP) in combination with threshold at the KFKI research reactor. The conventional IP produced by FUJI Photo Film Co. for the detection of beta and X-ray radiation were used. The threshold activation detectors were the reactions 115 In(n, n') 115m In, 64 Zn(n,p) 64 Cu, 56 Fe(n, p) 56 Mn, 24 Mg(n, p) 24 Na and 27 Al(n, α) 24 Na. These threshold reactions cover the fast neutron energy region between 0,7 MeV and 12 MeV. Pure, commercially available metals 0,1 mm to 0,25 mm thick made of In, Zn, Fe, Mg and Al were used as converter screens. The very high sensitivity of IP, the linearity of their response over 5 decades of exposure dose and the high dynamic digitalisation latitude enabled fast neutron radiography of image quality comparable to the quality of thermal NR. In our experimental conditions (φ n ∼ 10 8 n/cm 2 s, R Cd ∼ 2) the neutron exposure and IP exposure periods were still practical and comparable to the half life of the corresponding reaction products (half an hour to several hours). Even with the 27 Al(n.α) 24

  15. Neutron scattering. Lectures

    Energy Technology Data Exchange (ETDEWEB)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner (eds.)

    2012-07-01

    The following topics are dealt with: Neutron scattering in contemporary research, neutron sources, symmetry of crystals, diffraction, nanostructures investigated by small-angle neutron scattering, the structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic scattering, strongly correlated electrons, dynamics of macromolecules, applications of neutron scattering. (HSI)

  16. Neutron scattering. Lectures

    Energy Technology Data Exchange (ETDEWEB)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner (eds.)

    2013-07-01

    The following topics are dealt with: Neutron sources, symmetry of crystals, nanostructures investigated by small-angle neutron scattering, structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic neutron scattering, strongly correlated electrons, polymer dynamics, applications of neutron scattering. (HSI)

  17. Pulsed neutron generator

    International Nuclear Information System (INIS)

    Bespalov, D.F.; Bykovskii, Yu.A.; Vergun, I.I.; Kozlovskii, K.I.; Kozyrev, Yu.P.; Leonov, R.K.; Simagin, B.I.; Tsybin, A.S.; Shikanov, A.Ie.

    1986-03-01

    The paper describes a new device for generating pulsed neutron fields, utilized in nuclear geophysics for carrying out pulsed neutron logging and activation analysis under field conditions. The invention employs a sealed-off neutron tube with a laser ion source which increases neutron yield to the level of 10 neutrons per second or higher. 2 refs., 1 fig

  18. Neutron scattering. Lectures

    International Nuclear Information System (INIS)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

    2012-01-01

    The following topics are dealt with: Neutron scattering in contemporary research, neutron sources, symmetry of crystals, diffraction, nanostructures investigated by small-angle neutron scattering, the structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic scattering, strongly correlated electrons, dynamics of macromolecules, applications of neutron scattering. (HSI)

  19. Neutron scattering. Lectures

    International Nuclear Information System (INIS)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

    2013-01-01

    The following topics are dealt with: Neutron sources, symmetry of crystals, nanostructures investigated by small-angle neutron scattering, structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic neutron scattering, strongly correlated electrons, polymer dynamics, applications of neutron scattering. (HSI)

  20. The CERES / NA45 experiment

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    Ceres is one of the second generation heavy ion experiments at CERN's SPS. It is dedicated to the study of electron-positron pairs in relativistic nuclear collisions. NA45 is one of the seven experiments (NA44, NA45, NA49, NA50, NA52, WA97/NA57 and WA98) involved in CERN's Heavy Ion programme which provided evidence for the existence of a new state of matter, the quark-gluon plasma. In this state, quarks, instead of being bound up into more complex particles such as protons and neutrons, are liberated and roam freely. Theory predicts that this state must have existed at about 10 microseconds after the Big Bang, before the formation of matter as we know it today.

  1. Neutron scattering

    International Nuclear Information System (INIS)

    1991-02-01

    The annual report on hand gives an overview of the research work carried out in the Laboratory for Neutron Scattering (LNS) of the ETH Zuerich in 1990. Using the method of neutron scattering, it is possible to examine in detail the static and dynamic properties of the condensed material. In accordance with the multidisciplined character of the method, the LNS has for years maintained a system of intensive co-operation with numerous institutes in the areas of biology, chemistry, solid-state physics, crystallography and materials research. In 1990 over 100 scientists from more than 40 research groups both at home and abroad took part in the experiments. It was again a pleasure to see the number of graduate students present, who were studying for a doctorate and who could be introduced into the neutron scattering during their stay at the LNS and thus were in the position to touch on central ways of looking at a problem in their dissertation using this modern experimental method of solid-state research. In addition to the numerous and interesting ways of formulating the questions to explain the structure, nowadays the scientific programme increasingly includes particularly topical studies in connection with high temperature-supraconductors and materials research

  2. Atmospheric pollution biomonitoring of the Sao Paulo metropolitan region using epiphytic lichens; Uso de liquens epifiticos no biomonitoramento da poluicao atmosferica da regiao metropolitana de Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Fuga, Alessandra

    2006-07-01

    Due to the increasing problems of atmospheric pollution in the Sao Paulo metropolitan region that affect the environment and human health the application of biomonitoring methodologies using cosmopolite organisms has now become relevant. Biomonitoring is a method to evaluate the response of live organisms to pollution. This method offers advantages such as reduced costs, efficient monitoring of large geographic areas and accumulated pollutants over a large period in which low concentrations of chemicals elements in the environment can be evaluated. In the present study, neutron activation analysis method was applied to determine elements accumulated in Canoparmelia texana lichenized fungi. Samples were collected in two distinct areas: Carlos Botelho (PECB) and Intervales (PEI) State Parks that are considered as non-polluted areas and that belong to the Atlantic Forest - SP ecosystem; and Sao Paulo city metropolitan region in sites near automatic monitoring stations of the Environmental Protection Agency of the State of Sao Paulo (CETESB). The lichens collected from the bark of the trees were properly treated, and irradiated with neutrons from IEA-R1 nuclear reactor along with synthetic standards of elements. The precision and the accuracy of the results were evaluated by the analyses of IAEA-336 LICHEN and Mixed Polish Herbs (INCT -MPH-2) certified reference materials. The results obtained for these materials were in accordance with the certified values and presented good precision with variation coefficients ranging from 0.9 to 14.6%. Results obtained for lichens showed that elements As, Co, Cr, Cs, La, Mo, Sb, Sc, Se and U are present at ng g{sup -1} levels, Ba, Br, Cl, Fe, K, Mn, Na, Rb and Zn at {mu}g g{sup -1} and Ca at mg g{sup -1}. By applying cluster and discriminant analyses to the results for the lichen samples from areas with different levels of pollution, the sampling sites were grouped according to their chemical similarities and their elemental

  3. The measurements of thermal neutron flux distribution in a paraffin ...

    Indian Academy of Sciences (India)

    neutron flux density, the foil activation method was used. Thermal neutron flux determination in paraffin phantom by counting the emitted rays of indium foils with two different detectors (Geiger–. Muller counter and NaI(Tl)) was the aim of this project. The relative differences of the outcome of the experiments were between ...

  4. The measurements of thermal neutron flux distribution in a paraffin ...

    Indian Academy of Sciences (India)

    at 293.4 K. In order to measure the thermal neutron flux density, the foil activation method was used. Thermal neutron flux determination in paraffin phantom by counting the emitted rays of indium foils with two different detectors (Geiger–. Muller counter and NaI(Tl)) was the aim of this project. The relative differences of the ...

  5. Report from the neutron diffraction work group

    International Nuclear Information System (INIS)

    1978-08-01

    This progress report of the neutron diffraction group at the Hahn Meitner Institute in Berlin comprises the following contributions: Three-dimensional critical properties of CsNiF 3 around the Neel point; Spin waves in CsNiF 3 with an applied magnetic field; Solitons in CsNiF 3 : Their experimental evidence and their thermodynamics; Neutron diffraction study of DAG at very low temperatures and in external magnetic field; Neutron diffraction investigation of tricritical behaviour in DyPO 4 ; Crystalline modifications and structural phase transitions of NaOH; Gitterdynamik von Cerhydrid; Investigation of the ferroelectric-ferroelastic phase transition in KH 2 PO 4 and RbH 2 PO 4 by means of γ-ray diffractometry; A γ-ray diffractometer for systematic measurements of absolute structure factors; Electron density in pyrite by combined γ-ray and neutron diffraction measurements: Thermal parameters from short wavelength neutron data; Accurate determination of temperature parameters from neutron diffraction data: Direct observation of the thermal diffuse scattering from silicon using perfect crystals; A Compton spectrometer for momentum density studies using 412 keV γ-radiation; Investigation of the electronic structure of Niobiumhydrides by means of gamma-ray Compton scattering; Interpretation of Compton profile data in position space; High resolution neutron scattering measurements on single crystals using a horizontally bent monochromator and a multidetecter; Statistical analysis of neutron diffraction studies of proteins. (orig.) [de

  6. Spallation Neutron Source (SNS)

    Data.gov (United States)

    Federal Laboratory Consortium — The SNS at Oak Ridge National Laboratory is a next-generation spallation neutron source for neutron scattering that is currently the most powerful neutron source in...

  7. Neutron structure analysis using neutron imaging plate

    International Nuclear Information System (INIS)

    Karasawa, Yuko; Minezaki, Yoshiaki; Niimura, Nobuo

    1997-01-01

    Neutron is complementary against X-ray and is dispensable for structure analysis. However, because of the lack of the neutron intensity, it was not so common as X-ray. In order to overcome the intensity problem, a neutron imaging plate (NIP) has been successfully developed. The NIP has opened the door of neutron structure biology, where all the hydrogen atoms and bound water molecules of protein are determined, and contributed to development of other fields such as neutron powder diffraction and neutron radiography, too. (author)

  8. Neutron scattering. Lectures

    Energy Technology Data Exchange (ETDEWEB)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner (eds.)

    2010-07-01

    The following topics are dealt with: Neutron sources, neutron properties and elastic scattering, correlation functions measured by scattering experiments, symmetry of crystals, applications of neutron scattering, polarized-neutron scattering and polarization analysis, structural analysis, magnetic and lattice excitation studied by inelastic neutron scattering, macromolecules and self-assembly, dynamics of macromolecules, correlated electrons in complex transition-metal oxides, surfaces, interfaces, and thin films investigated by neutron reflectometry, nanomagnetism. (HSI)

  9. REFRACTIVE NEUTRON LENS

    OpenAIRE

    Petrov, P. V.; Kolchevsky, N. N.

    2013-01-01

    Compound concave refractive lenses are used for focusing neutron beam. Investigations of spectral and focusing properties of a refractive neutron lens are presented. Resolution of the imaging system on the base of refractive neutron lenses depends on material properties and parameters of neutron source. Model of refractive neutron lens are proposed. Results of calculation diffraction resolution and focal depth of refractive neutron lens are discussed.

  10. High energy neutron radiography

    International Nuclear Information System (INIS)

    Gavron, A.; Morley, K.; Morris, C.; Seestrom, S.; Ullmann, J.; Yates, G.; Zumbro, J.

    1996-01-01

    High-energy spallation neutron sources are now being considered in the US and elsewhere as a replacement for neutron beams produced by reactors. High-energy and high intensity neutron beams, produced by unmoderated spallation sources, open potential new vistas of neutron radiography. The authors discuss the basic advantages and disadvantages of high-energy neutron radiography, and consider some experimental results obtained at the Weapons Neutron Research (WNR) facility at Los Alamos

  11. Neutron scattering. Lectures

    International Nuclear Information System (INIS)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

    2010-01-01

    The following topics are dealt with: Neutron sources, neutron properties and elastic scattering, correlation functions measured by scattering experiments, symmetry of crystals, applications of neutron scattering, polarized-neutron scattering and polarization analysis, structural analysis, magnetic and lattice excitation studied by inelastic neutron scattering, macromolecules and self-assembly, dynamics of macromolecules, correlated electrons in complex transition-metal oxides, surfaces, interfaces, and thin films investigated by neutron reflectometry, nanomagnetism. (HSI)

  12. The use of a thermal neutron beam for the narcotics and explosives detection using tomography, applied on the national public safety; Uso de um feixe de neutrons termicos para a deteccao de narcoticos e explosivos por tomografia, para aplicacao na seguranca publica nacional

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ademir Xavier da

    1999-08-01

    Aiming to even more extend the range of the applications, we demonstrate, on this work, the potentialities of neutron radiography, allied to the computerized tomography by transmission, for the detection of drugs and explosives concealed by several materials intending to the National Public Safety. We analysed: thermal neutron radiographs of cocaine samples under both different physics conditions and purity degrees, subjected to hidden conditions by lead, tobacco, iron and cotton cloth; tomographic images using thermal neutron beams obtained from both experimental and simulated dates of drug and explosive samples concealed by light and heavy materials. In the experimental testings, the samples were irradiated using thermal neutron beams coming from the J-9 irradiation channel of the Argonauta reactor of the IEN/CNEN, for 30 minutes, in a flux of 2,5 x 10{sup 5} n.cm{sup -2}.s{sup -1}. The MCNP was utilized either to generate the projection dates used on the simulate tomographs or to realize the moderation, collimation and shielding calculations of a neutron radiography system using {sup 252} Cf as a neutron source. Analysis the images of drug samples, we conclude that the neutron radiography was able to detect them, even hidden by the above cited materials. Using the obtained images, it was possible to demonstrate the potential of a tomography utilizing thermal neutron beams for the same detection. According to the neutronic calculations, we estimate a thermal neutron beam, on the image plane, up to 7x10{sup 5} n.cm{sup -2}..s{sup -1}, considering 50 mg of {sup 252} Cf with a collimation ratio of 7,5. (author)

  13. Accuracy of the thermal neutron absorption cross section measurements (based on examples of selected pulsed beam methods); Dokladnosc pomiarow przekroju czynnego absorpcji neutronow termicznych (na przykladzie wybranych metod impulsowych)

    Energy Technology Data Exchange (ETDEWEB)

    Krynicka, E. [The H. Niewodniczanski Inst. of Nuclear Physics, Cracow (Poland)

    1997-12-31

    The problem of accuracy of the thermal neutron macroscopic absorption cross section determination is discussed on examples of selected measurement methods which use non-stationary neutron fields. The computer simulation method elaborated by the author is presented as a procedure for estimating the standard deviation of the measured absorption cross section. The computer simulation method presented can be easily utilized to estimate the accuracy of measurement of various physical magnitudes. (author) 46 refs, 3 figs, 1 tab

  14. Neutron Therapy Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Neutron Therapy Facility provides a moderate intensity, broad energy spectrum neutron beam that can be used for short term irradiations for radiobiology (cells)...

  15. Neutron microdosimetry

    International Nuclear Information System (INIS)

    Kliauga, P.

    1987-01-01

    A major effort was made during the past year to do precision microdosimetry of neutrons at the RARAF facility. By precision microdosimetry the authors mean a special effort to understand, better than previously, some of the factors which go into the limitation of the accuracy and precision of microdosimetric measurements of neutrons. That such factors are still not clearly understood, or at least accounted for, is immediately evident upon examination of published microdosimetric measurements. What becomes immediately apparent upon examination of, say, the dose mean lineal energies reported, is that the spread of reported values for exceeds the reported experimental uncertainty, commonly taken as about 5%. Differences of 50% are not uncommon. It is easy to make the mistake that since classical microdosimetry uses a well-established experimental tool, the proportional counter, that sources of error should also be well understood. However, microdosimetry makes use of the proportional counter in a way which is quite different from its origins as a low-energy photon spectroscopy device. Microdosimetric spectra, particularly of neutrons, span 5 to 6 decades of event sizes. It is by no means certain that proportionality extends over such a range, and in fact it has been pointed out that it probably does not. Data analysis techniques vary from one experimenter to another, and can substantially affect mean values as well as spectral shape. The authors are examining these parameters, as well as others, such as calibration errors, but they are especially concentrating on the effect of counter design and performance on the resultant spectra which the counter measures

  16. Prompt γ rays and neutrons from fission

    Science.gov (United States)

    Kwan, E.; Wu, C. Y.; Chyzh, A.; Gostic, J.; Henderson, R.; Haight, R. C.; Lee, H. Y.; O'Donnell, J. M.; Perdue, B. A.; Taddeucci, T. N.

    2011-10-01

    Nuclear data are needed to test the accuracy of calculations from nuclear reaction codes. Information on the prompt γ-ray distributions from fission is sparse and only a handful of published experiments data that measured the prompt γ-ray distribution above incident neutron energies of 1 MeV can be found. In addition, improvement on the accuracy and shape of neutron spectrum from the fission of actinides been requested by the nuclear data community. An investigation on the shapes of the neutron and γ-ray distributions from the spontaneous fission of 252Cf and the neutron-induced fission of 235U was undertaken using the Chi-Nu detector array at the Weapons Neutron Research Facility of the Los Alamos Neutron Science Center. Preliminary results will be presented. This work is performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and the Los Alamos National Laboratory under Contract DE-AC52-06NA25396.

  17. Calculation of neutron kerma in tissues

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H.R.; Manzanares A, E. [Unidades Academicas de Estudios Nucleares, Ing. Electrica y Matematicas, Universidad Autonoma de Zacatecas, A.P. 336, 98000 Zacatecas (Mexico)]. E-mail: rvega@cantera.reduaz.mx

    2004-07-01

    Neutron kerma of normal and tumor tissues has been calculated using the tissues elemental concentration. A program developed in Math cad contains the kerma factors of C, H, O, N, Na, Mg, P, S, Cl, K, etc. that are in normal and tumor human tissues. Having the elemental composition of any human tissue the neutron kerma can be calculated. The program was tested using the elemental composition of tumor tissues such as sarcoma, melanoma, carcinoma and adenoid cystic, also neutron kerma for adipose and muscle tissue for normal adult was calculated. The results are in agreement with those published in literature. The neutron kerma for water was also calculated because in some dosimetric calculations water is used to describe normal and tumor tissues. From this comparison was found that at larger energies kerma factors are approximately the same, but energies less than 100 eV the differences are large. (Author)

  18. Calculation of neutron kerma in tissues

    International Nuclear Information System (INIS)

    Vega C, H.R.; Manzanares A, E.

    2004-01-01

    Neutron kerma of normal and tumor tissues has been calculated using the tissues elemental concentration. A program developed in Math cad contains the kerma factors of C, H, O, N, Na, Mg, P, S, Cl, K, etc. that are in normal and tumor human tissues. Having the elemental composition of any human tissue the neutron kerma can be calculated. The program was tested using the elemental composition of tumor tissues such as sarcoma, melanoma, carcinoma and adenoid cystic, also neutron kerma for adipose and muscle tissue for normal adult was calculated. The results are in agreement with those published in literature. The neutron kerma for water was also calculated because in some dosimetric calculations water is used to describe normal and tumor tissues. From this comparison was found that at larger energies kerma factors are approximately the same, but energies less than 100 eV the differences are large. (Author)

  19. Neutron matter, symmetry energy and neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Stefano, Gandolfi [Los Alamos National Laboratory (LANL); Steiner, Andrew W [ORNL

    2016-01-01

    Recent progress in quantum Monte Carlo with modern nucleon-nucleon interactions have enabled the successful description of properties of light nuclei and neutron-rich matter. Of particular interest is the nuclear symmetry energy, the energy cost of creating an isospin asymmetry, and its connection to the structure of neutron stars. Combining these advances with recent observations of neutron star masses and radii gives insight into the equation of state of neutron-rich matter near and above the saturation density. In particular, neutron star radius measurements constrain the derivative of the symmetry energy.

  20. Neutron scattering. Lectures

    Energy Technology Data Exchange (ETDEWEB)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner (eds.)

    2010-07-01

    The following topics are dealt with: Neutron sources, symmetry of crystals, diffraction, nanostructures investigated by small-angle neutron scattering, the structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic scattering, strongly correlated electrons, dynamics of macromolecules, applications of neutron scattering. (HSI)

  1. Neutron generator control system

    International Nuclear Information System (INIS)

    Peelman, H.E.; Bridges, J.R.

    1981-01-01

    A method is described of controlling the neutron output of a neutron generator tube used in neutron well logging. The system operates by monitoring the target beam current and comparing a function of this current with a reference voltage level to develop a control signal used in a series regulator to control the replenisher current of the neutron generator tube. (U.K.)

  2. Neutron scattering. Lectures

    International Nuclear Information System (INIS)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

    2010-01-01

    The following topics are dealt with: Neutron sources, symmetry of crystals, diffraction, nanostructures investigated by small-angle neutron scattering, the structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic scattering, strongly correlated electrons, dynamics of macromolecules, applications of neutron scattering. (HSI)

  3. Nuclear reactor neutron shielding

    Science.gov (United States)

    Speaker, Daniel P; Neeley, Gary W; Inman, James B

    2017-09-12

    A nuclear reactor includes a reactor pressure vessel and a nuclear reactor core comprising fissile material disposed in a lower portion of the reactor pressure vessel. The lower portion of the reactor pressure vessel is disposed in a reactor cavity. An annular neutron stop is located at an elevation above the uppermost elevation of the nuclear reactor core. The annular neutron stop comprises neutron absorbing material filling an annular gap between the reactor pressure vessel and the wall of the reactor cavity. The annular neutron stop may comprise an outer neutron stop ring attached to the wall of the reactor cavity, and an inner neutron stop ring attached to the reactor pressure vessel. An excore instrument guide tube penetrates through the annular neutron stop, and a neutron plug comprising neutron absorbing material is disposed in the tube at the penetration through the neutron stop.

  4. Miscellaneous neutron techniques

    International Nuclear Information System (INIS)

    Iddings, F.A.

    1976-01-01

    Attention is brought to the less often uses of neutrons in the areas of neutron radiography, well logging, and neutron gaging. Emphasis on neutron radiography points toward the isotopic sensitivity of the method versus the classical bulk applications. Also recognized is the ability of neutron radiography to produce image changes that correspond to thickness and density changes obtained in photon radiography. Similarly, neutron gaging applications center on the measurement of radiography. Similarly, neutron gaging applications center on the measurement of water, oil, or plastics in industrial samples. Well logging extends the neutron gaging to encompass many neutron properties and reactions besides thermalization and capture. Neutron gaging also gives information on organic structure and concentrations of a variety of elements or specific compounds in selected matrices

  5. Neutrons in science and technology

    International Nuclear Information System (INIS)

    Bromley, D.A.

    1984-01-01

    Occasionally to the fiftieth anniversy of the discovery of the neutron the author presents a historical review about the impact of this discovery on different fields at physics. Especially considered are nuclear physics, the neutron as an elementary particles, ultracold neutrons, condensed matter physics, radiation damage induced by neutrons, neutron activation analysis, imaging and radiography by neutrons, neutrons in mining operations, track etching, the use of intense gamma sources, gauging systems, neutron holography and neutron stars. (HSI)

  6. Neutron and gamma-ray spectra of 239PuBe and 241AmBe

    International Nuclear Information System (INIS)

    Vega-Carrillo, H.R.; Manzanares-Acuna, Eduardo; Becerra-Ferreiro, A.M.; Carrillo-Nunez, Aureliano

    2002-01-01

    Neutron and gamma-ray spectra of 239 PuBe and 241 AmBe were measured and their dosimetric features were calculated. Neutron spectra were measured using a multisphere neutron spectrometer with a 6 LiI(Eu) scintillator. The 239 PuBe neutron spectrum was measured in an open environment, while the 241 AmBe neutron spectrum was measured in a closed environment. Gamma-ray spectra were measured using a NaI(Tl) scintillator using the same experimental conditions for both sources. The effect of measuring conditions for the 241 AmBe neutron spectrum indicates the presence of epithermal and thermal neutrons. The low-resolution neutron spectra obtained with the multisphere spectrometer allows one to calculate the dosimetric features of neutron sources. At 100 cm both sources produce approximately the same count rate as that of the 4.4 MeV gamma-ray per unit of alpha emitter activity

  7. Comparison between {sup 241}AmBe (α, n) sources in the calibration of survey monitors for neutrons in magnitude H⁎(10); Comparação entre fontes de {sup 241}AmBe (α,n) na calibração de monitores de área para nêutrons na grandeza H⁎(10)

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, W.W.; Filho, C.A.L.S.; Silva, F.S.; Patrão, K.C.S., E-mail: walsanwagner@gmail.com [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Estrada, J.J.S. [Fundação Técnico Educacional Souza Marques, Rio de Janeiro, RJ (Brazil); Alves, C.F.E.; Magalhães, L.A.G.; Leite, S.P. [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil)

    2017-07-01

    Recently the Laboratório de Ciências Radiológicas (LCR / UERJ) characterized a {sup 241}AmBe (α, n) neutron source for metrological use. This source comes from the Oil Company and it was originally used in well logging tools. In this work, this source was used in the calibration of an survey meter using procedures and facilities of the Laboratório Nacional de Metrologia das Radiações Ionizantes (LN/LNMRI). The results of the calibration with the LCR neutron source agreed with those obtained when the LN/LNMRI neutron source was used. (author)

  8. Small angle neutron scattering studies of mixed micelles of sodium

    Indian Academy of Sciences (India)

    The aqueous solutions of sodium cumene sulphonate (NaCS) and its mixtures with each of cetyl trimethylammonium bromide (CTAB) and sodium dodecyl sulphate (SDS) are characterized by small angle neutron scattering (SANS). NaCS when added to CTAB solution leads to the formation of long rod-shaped micelles with ...

  9. Neutron shielding properties of a borated high-density glass

    Directory of Open Access Journals (Sweden)

    Saeed Aly Abdallah

    2017-01-01

    Full Text Available The neutron shielding properties of a borated high density glass system was characterized experimentally. The total removal macroscopic cross-section of fast neutrons, slow neutrons as well as the linear attenuation coefficient of total gamma rays, primary in addition to secondary, were measured experimentally under good geometric condition to characterize the attenuation properties of (75-x B2O3-1Li2O-5MgO-5ZnO-14Na2O-xBaO glassy system. Slabs of different thicknesses from the investigated glass system were exposed to a collimated beam of neutrons emitted from 252Cf and 241Am-Be neutron sources in order to measure the attenuation properties of fast and slow neutrons as well as total gamma rays. Results confirmed that barium borate glass was suitable for practical use in the field of radiation shielding.

  10. Evaluation of ensemble atmospheric simulations in oil dispersion models at Itaguai Port region; Avaliacao do uso de resultados numericos de previsao atmosferica por conjunto na modelagem da dispersao de oleo na regiao do Porto de Itaguai

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Renato Goncalves dos; Silva, Mariana P.R.; Silva, Ricardo Marcelo da; Torres Junior, Audalio R. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Lab. de Modelagem de Processos Marinhos e Atmosfericos (LAMMA); Landau, Luiz [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Lab. de Metodos Computacinais em Engenharia (LAMCE); Sa, Reginaldo Ventura de; Hochleitner, Fabio; Correa, Eduardo Barbosa [AQUAMET Meteorologia e Projeto de Sistemas, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    This work discusses the use of numerical prediction using ensemble as boundary condition in pollutants dispersion models, applied in a hypothetical case of an oil spill occurrence in Itaguai Port. The Princeton Ocean Model (POM) has been used to simulate hydrodynamics and NICOIL Eulerian model to forecast oil spill dispersion, and ensemble wind forecast from Global Forecast System (GFS), aiming to assess the importance of this parameter variability in oil dispersion at sea. The wind scenarios using ensemble members has showed significant dispersion when compared to control simulation, demonstrating that the uncertainty in the atmospheric modeling can generate considerable variations in the placement of the final spot of oil. The region of interest was the Sepetiba Bay, located on the southern coast of the Rio de Janeiro state; because of port operations carried out around the Port of Itaguai where they can, eventually, oil leaks occur. (author)

  11. Characterization of a red ceramic body used in the manufacture of ceramic bricks in the region of Campos dos Goytacazes, RJ, Brazil; Caracterizacao de massa ceramica vermelha utilizada na fabricacao de blocos ceramicos na regiao de Campos dos Goytacazes

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, L.L.P. de; Petrucci, L.J.T.; Pessanha, E.M.; Paixao, L.P.; Maia, F.S. [Faetec, Campos dos Goytacazes, RJ (Brazil). Centro Vocacional Tecnologico. Ceramica

    2010-07-01

    This work aims at the physical and mineralogical characterization of a ceramic body, used industrially in the manufacture of ceramic bricks in the region of Campos dos Goytacazes. The clay was characterized by chemical composition, X-ray diffraction, dilatometry, differential thermal analysis and gravimetric. We test specimens were obtained by extrusion. The bodies were burned from 750 to 1000 deg C and then it was determined water absorption, linear shrinkage, loss on ignition and modulus of rupture. The results showed that the ceramic body consists mainly of kaolinite, quartz and feldspar is thus suitable for mass production of ceramic bricks in accordance with technical standards. (author)

  12. Characterization of clay and mass used in red ceramic industry in Cariri region - Ceara; Caracterizacao de argilas e massas utilizadas na industria G. Matos de ceramica vermelha na regiao do Cariri - Ceara

    Energy Technology Data Exchange (ETDEWEB)

    Neta, I.A.B.; Cartaxo, A.S.; Esmeraldo, A.D.; Gomes, F.F.; Silva, F.C.; Ribeiro, S.B.N.; Neiva, L.S.; Brasileiro, M.I. [Universidade Federal do Cariri (UFCA), Juazeiro do Norte, CE (Brazil)

    2016-07-01

    The study of the characteristics of raw materials used in the production of red ceramic industry articles, such as bricks and tiles, has a key role in determining the quality of the final product. This study aims to evaluate the chemical and physical properties of clays and pasta from pottery G. Matos, Crato, Ceara. Three samples were collected, processed and submitted to the characterization DRX. They were also analyzed for plasticity by the methods of Atterberg and Pfefferkorn. In the method Atterberg, samples and Fat Mass Ready clay are within the plasticity index range for red ceramics, Pferfferkorn method, pasta and ready Fat also had plasticity, but with different results of the above method. In both ostestes, the red mass showed no moldability. XRD, the samples show quartz peaks, which were in the greatest amount in the sample that did not develop plasticity, addition, montmorillonite obtained peaks kaolinite. (author)

  13. Neutron range spectrometer

    Science.gov (United States)

    Manglos, Stephen H.

    1989-06-06

    A neutron range spectrometer and method for determining the neutron energy spectrum of a neutron emitting source are disclosed. Neutrons from the source are collimnated along a collimation axis and a position sensitive neutron counter is disposed in the path of the collimated neutron beam. The counter determines positions along the collimation axis of interactions between the neutrons in the neutron beam and a neutron-absorbing material in the counter. From the interaction positions, a computer analyzes the data and determines the neutron energy spectrum of the neutron beam. The counter is preferably shielded and a suitable neutron-absorbing material is He-3. The computer solves the following equation in the analysis: ##EQU1## where: N(x).DELTA.x=the number of neutron interactions measured between a position x and x+.DELTA.x, A.sub.i (E.sub.i).DELTA.E.sub.i =the number of incident neutrons with energy between E.sub.i and E.sub.i +.DELTA.E.sub.i, and C=C(E.sub.i)=N .sigma.(E.sub.i) where N=the number density of absorbing atoms in the position sensitive counter means and .sigma. (E.sub.i)=the average cross section of the absorbing interaction between E.sub.i and E.sub.i +.DELTA.E.sub.i.

  14. Neutrons and materials

    International Nuclear Information System (INIS)

    Paulus, W.; Meinnel, J.

    2003-01-01

    The neutron is the only probe that gives information simultaneously on structure issues through interference phenomena and on dynamics issues through spectroscopy. The neutron carries a s=1/2 spin value which allows it to be polarizable and to interact with any magnetic field through the magnetic momentum associated to its spin. The great interest of neutron in research relies on 3 facts: -) the neutron fluxes used to study matter are supplied by nuclear reactors and spallation sources with wave lengths and energy range that directly correspond to interatomic distances and thermal-motion energies of matter, -) the possibility of setting or changing the contrast of an element by using its different isotopes, and -) the neutron does not carry an electrical charge so it can enter the bulk of matter easily and gives an image of stress and patterns of large pieces of metal through a non-destructive examination. This course reviews all the aspects of the use of neutron in physics and is made up of 16 chapters: 1) properties of neutrons, 2) neutron production, 3) complementarity between X-ray and neutrons, 4) neutron diffraction, 5) neutron diffusion, 6) neutron spectroscopy, 7) crystallography, 8) imaging techniques with neutrons, 9) neutron activation analysis, 10) low-angle diffusion, 11) neutron reflectivity, 12) non-destructive testing, 13) microstructure and diffraction rays of X-radiation, 14) access to neutron source facilities, 15) composites materials and neutron diffusion, and 16) studies of liquids and glasses through neutron and X-ray diffraction. (A.C.)

  15. A neutron activation detector

    International Nuclear Information System (INIS)

    Ambardanishvili, T.S.; Kolomiitsev, M.A.; Zakharina, T.Y.; Dundua, V.J.; Chikhladze, N.V.

    1973-01-01

    The present invention concerns a neutron activation detector made from a moulded and hardened composition. According to the invention, that composition contains an activable substance constituted by at least two chemical elements and/or compounds of at least two chemical elements. Each of these chemical elements is capable of reacting with the neutrons forming radio-active isotopes with vatious levels of energy during desintegration. This neutron detector is mainly suitable for measuring integral thermal neutron and fast neutron fluxes during irradiation of the sample, and also for measuring the intensities of neutron fields [fr

  16. Neutron in biology

    International Nuclear Information System (INIS)

    Niimura, Nobuo

    1997-01-01

    Neutron in biology can provide an experimental method of directly locating relationship of proteins and DNA. However, there are relatively few experimental study of such objects since it takes a lot of time to collect a sufficient number of Bragg reflections and inelastic spectra due to the low flux of neutron illuminating the sample. Since a next generation neutron source of JAERI will be 5MW spallation neutron source and its effective neutron flux will be 10 2 to 10 3 times higher than the one of JRR-3M, neutron in biology will open a completely new world for structural biology. (author)

  17. Layered semiconductor neutron detectors

    Science.gov (United States)

    Mao, Samuel S; Perry, Dale L

    2013-12-10

    Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

  18. C7LYC Scintillators and Fast Neutron Spectroscopy

    Science.gov (United States)

    Chowdhury, P.; Brown, T.; Doucet, E.; Lister, C. J.; Wilson, G. L.; D'Olympia, N.; Devlin, M.; Mosby, S.

    2016-09-01

    Cs2 LiYCl6 (CLYC) scintillators detect both gammas and neutrons with excellent pulse shape discrimination. At UML, fast neutron measurements with a 16-element 1''x1'' CLYC array show promise for low energy nuclear science. CLYC detects fast neutrons via the 35Cl (n,p) reaction (resolution < 10 % at < 8 MeV). In our 7Li-enriched C7LYC, the thermal neutron response from the 6Li(n, α)t reaction is virtually eliminated. The low intrinsic efficiency of CLYC for fast neutrons (< 1 %) is offset by increased solid angle with the array placed near the target, since TOF is not needed for energy resolution. The array was tested at LANL for measuring elastic and inelastic neutron scattering on 56Fe. The incident energy from the white neutron source was measured via TOF, and the scattered neutron energy via the pulse height in CLYC. The array was also tested at CARIBU for measuring beta-delayed neutrons. Larger CLYC crystals are now a reality. Measurements with the first 3'' x 3'' C7LYC crystal are in progress at UML. Results will be discussed in the context of constructing a C7LYC array at FRIB for reaction and decay spectroscopy of neutron-rich fragments. Supported by the NNSA Stewardship Science Academic Alliance Program under Grant DE-NA00013008.

  19. Neutron stochastic transport theory with delayed neutrons

    International Nuclear Information System (INIS)

    Munoz-Cobo, J.L.; Verdu, G.

    1987-01-01

    From the stochastic transport theory with delayed neutrons, the Boltzmann transport equation with delayed neutrons for the average flux emerges in a natural way without recourse to any approximation. From this theory a general expression is obtained for the Feynman Y-function when delayed neutrons are included. The single mode approximation for the particular case of a subcritical assembly is developed, and it is shown that Y-function reduces to the familiar expression quoted in many books, when delayed neutrons are not considered, and spatial and source effects are not included. (author)

  20. High-pressure cell for neutron scattering

    International Nuclear Information System (INIS)

    Onodera, Akifumi; Nakai, Yutaka; Kunitomi, Nobuhiko

    1987-01-01

    We have developed a high-pressure cell for neutron scattering. The cell uses a barrel-shaped support cylinder made of sintered ceramics. Samples 6 mm in diameter and 10 mm long can be accommodated. The cell is suitable for use at low and high temperatures, after a pressure generated at room temperature is locked. The change of pressure on cooling to cryogenic temperatures is estimated by measuring the lattice parameter of NaCl. Besides the pressure locking technique, continuous pressurization can be achieved at room temperature by using a built-in mini-press while the cell is mounted on a goniometer of neutron spectrometer. (author)

  1. Neutron anatomy

    International Nuclear Information System (INIS)

    Bacon, G.E.

    1994-01-01

    The familiar extremes of crystalline material are single-crystals and random powders. In between these two extremes are polycrystalline aggregates, not randomly arranged but possessing some preferred orientation and this is the form taken by constructional materials, be they steel girders or the bones of a human or animal skeleton. The details of the preferred orientation determine the ability of the material to withstand stress in any direction. In the case of bone the crucial factor is the orientation of the c-axes of the mineral content - the crystals of the hexagonal hydroxyapatite - and this can readily be determined by neutron diffraction. In particular it can be measured over the volume of a piece of bone, utilizing distances ranging from 1mm to 10mm. The major practical problem is to avoid the intense incoherent scattering from the hydrogen in the accompanying collagen; this can best be achieved by heat-treatment and it is demonstrated that this does not affect the underlying apatite. These studies of bone give leading anatomical information on the life and activities of humans and animals - including, for example, the life history of the human femur, the locomotion of sheep, the fracture of the legs of racehorses and the life-styles of Neolithic tribes. We conclude that the material is placed economically in the bone to withstand the expected stresses of life and the environment. The experimental results are presented in terms of the magnitude of the 0002 apatite reflection. It so happens that for a random powder the 0002, 1121 reflections, which are neighboring lines in the powder pattern, are approximately equal in intensity. The latter reflection, being of manifold multiplicity, is scarcely affected by preferred orientation so that the numerical value of the 0002/1121 ratio serves quite accurately as a quantitative measure of the degree of orientation of the c-axes in any chosen direction for a sample of bone

  2. Neutron anatomy.

    Science.gov (United States)

    Bacon, G E

    1996-01-01

    The familiar extremes of crystalline material are single-crystals and random powders. In between these two extremes are polycrystalline aggregates, not randomly arranged but possessing some preferred orientation and this is the form taken by constructional materials, be they steel girders or the bones of a human or animal skeleton. The details of the preferred orientation determine the ability of the material to withstand stress in any direction. In the case of bone the crucial factor is the orientation of the c-axes of the mineral content-the crystals of the hexagonal hydroxyapatite- and this can readily be determined by neutron diffraction. In particular it can be measured over the volume of a piece of bone, utilising distances ranging from 1 mm to 10 mm. The major practical problem is to avoid the intense incoherent scattering from the hydrogen in the accompanying collagen; this can best be achieved by heat-treatment and it is demonstrated that this does not affect the underlying apatite. These studies of bone give leading anatomical information on the life and activities of humans and animals-including, for example, the life history of the human femur, the locomotion of sheep, the fracture of the legs of racehorses and the life-styles of Neolithic tribes. We conclude that the material is placed economically in the bone to withstand the expected stresses of life and the environment. The experimental results are presented in terms of the magnitude of the 0002 apatite reflection. It so happens that for a random powder the 0002, 1121 reflections, which are neighbouring lines in the powder pattern, are approximately equal in intensity. The latter reflection, being of manifold multiplicity, is scarcely affected by preferred orientation so that the numerical value of the 0002/1121 ratio serves quite accurately as a quantitative measure of the degree of orientation of the c-axes in any chosen direction, for a sample of bone.

  3. Fundamentals and applications of neutron imaging. Fundamentals part 5. Neutron sources for neutron imaging

    International Nuclear Information System (INIS)

    Matsubayashi, Masahito

    2007-01-01

    Neutrons for experiments by neutron beams are classified regarding neutron sources as follows: (1) Neutrons from radioisotopes, (2) Neutrons from nuclear reactions induced by deuteron beams from accelerators, (3) Neutrons from nuclear spallation induced by high energy proton beams from accelerators, and (4) Neutrons from reactors. As for the neutron imaging, weak intensity neutron sources can be useful if the detector system is sensitive enough. A newly developed spallation neutron source has eminent characteristics that the neutron emission is pulsive with strong peak intensity. Imaging experiments availing this property will be developed henceforth. (K. Yoshida)

  4. Determination of the neutron fluence spectra in the neutron therapy room of KIRAMS.

    Science.gov (United States)

    Kim, B H; Kim, J S; Kim, J L; Kim, Y S; Yang, T G; Lee, M Y

    2007-01-01

    High energy proton induced neutron fluence spectra were determined at the Korea Institute of Radiological and Medical Sciences (KIRAMS) using an extended Bonner Sphere (BS) set from the Korea Atomic Energy Research Institute (KAERI) in a series of measurements to quantify the neutron field. At the facility of the MC50 cyclotron of KIRAMS, two Be targets of different thicknesses, 1.0 and 10.5 mm, were bombarded by 35 and 45-MeV protons to produce six kinds of neutron fields, which were classified according to the measurement position and the use or no use of a beam collimator such as the gantry of the neutron therapy unit. In order to obtain a priori information to unfold the measured BS data the MCNPX code was used to calculate the neutron spectrum, and the influence of the surrounding materials for cooling the target assembly were also reviewed through this calculation. Some dosimetric quantities were determined by using the spectra determined in this measurement. Dose equivalent rates of these neutron fields ranged from 0.21 to 5.66 mSv h(-1)nA(-1) and the neutron yields for a thick Be target were 3.05 and 4.77% in the case of using a 35 and a 45-MeV proton, respectively.

  5. Determination of the neutron fluence spectra in the neutron therapy room of KIRAMS

    International Nuclear Information System (INIS)

    Kim, B. H.; Kim, J. S.; Kim, J. L.; Kim, Y. S.; Yang, T. G.; Lee, M. Y.

    2007-01-01

    High energy proton induced neutron fluence spectra were determined at the Korea Inst. of Radiological and Medical Sciences (KIRAMS) using an extended Bonner Sphere (BS) set from the Korea Atomic Energy Research Inst. (KAERI) in a series of measurements to quantify the neutron field. At the facility of the MC50 cyclotron of KIRAMS, two Be targets of different thicknesses, 1.0 and 10.5 mm, were bombarded by 35 and 45-MeV protons to produce six kinds of neutron fields, which were classified according to the measurement position and the use or no use of a beam collimator such as the gantry of the neutron therapy unit. In order to obtain a priori information to unfold the measured BS data the MCNPX code was used to calculate the neutron spectrum, and the influence of the surrounding materials for cooling the target assembly were also reviewed through this calculation. Some dosimetric quantities were determined by using the spectra determined in this measurement. Dose equivalent rates of these neutron fields ranged from 0.21 to 5.66 mSv h -1 nA -1 and the neutron yields for a thick Be target were 3.05 and 4.77% in the case of using a 35 and a 45-MeV proton, respectively. (authors)

  6. Intense fusion neutron sources

    Science.gov (United States)

    Kuteev, B. V.; Goncharov, P. R.; Sergeev, V. Yu.; Khripunov, V. I.

    2010-04-01

    The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 1015-1021 neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 1020 neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

  7. Neutron beams for therapy

    International Nuclear Information System (INIS)

    Kuplenikov, Eh.L.; Dovbnya, A.N.; Telegin, Yu.N.; Tsymbal, V.A.; Kandybej, S.S.

    2011-01-01

    It was given the analysis and generalization of the study results carried out during some decades in many world countries on application of thermal, epithermal and fast neutrons for neutron, gamma-neutron and neutron-capture therapy. The main attention is focused on the practical application possibility of the accumulated experience for the base creation for medical research and the cancer patients effective treatment.

  8. Reactor Neutron Sources

    International Nuclear Information System (INIS)

    Aksenov, V.L.

    1994-01-01

    The present status and the prospects for development of reactor neutron sources for neutron scattering research in the world are considered. The fields of application of neutron scattering relative to synchrotron radiation, the creation stages of reactors (steady state and pulsed) and their position in comparison with spallation neutron sources at present and in the foreseen future are discussed. (author). 15 refs.; 8 figs.; 3 tabs

  9. Properties of neutron sources

    International Nuclear Information System (INIS)

    1987-03-01

    The Conference presentations were divided into sessions devoted to the following topics: white neutron sources, primarily pulsed (6 papers); fast neutron fields (5 papers); Californium-252 prompt fission neutron spectra (14 papers); monoenergetic sources and filtered beams (11 papers); 14 MeV neutron sources (10 papers); selected special application (one paper); and a general interest session (4 papers). Individual abstracts were prepared separately for the papers

  10. Polarimetric neutron scattering

    International Nuclear Information System (INIS)

    Tasset, F.

    2001-01-01

    Polarimetric Neutron Scattering in introduced, both by, explaining methodological issues and the corresponding instrumental developments. After a short overview of neutron spin polarization and the neutron polarization 3d-vector a pictorial approach of the microscopic theory is used to show how a polarized beam interacts with lattice and magnetic Fourier components in a crystal. Examples are given of using Spherical Neutron Polarimetry (SNP) and the corresponding Cryopad polarimeter for the investigation of non-collinear magnetic structures. (R.P.)

  11. Crystal structure of 0.96(Na0.5Bi0.5TiO3)-0.04(BaTiO3) from combined refinement of x-ray and neutron diffraction patterns

    Energy Technology Data Exchange (ETDEWEB)

    Usher, T -M; Forrester, J S; dela Cruz, C R; Jones, J L [ORNL; (Florida)

    2012-10-12

    High-resolution x-ray and neutron diffraction of (0.96)Na0.5Bi0.5TiO3–(0.04)BaTiO3 (NBT-4BT) reveal subtle structural distortions that evidence lower symmetry than allowed in the R3c space group. The combined refinement that best models the diffraction patterns is a two phase mixture of a monoclinic Cc phase and a minor fraction of a metrically cubic Pm 3¯ m phase (13 wt. %). The cubic phase is utilized to account for nanometer-scale regions whose local deviations from the long-range symmetry are not observed, such as polar nano-regions or tetragonal platelets. This suggests that the low symmetry found in the NBT-rich phases extends from 0 at. % to at least 4 at. % BT.

  12. Determination of the neutron mass

    International Nuclear Information System (INIS)

    Amador V, P.; Chacon R, A.; Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Vega C, H.R.

    2005-01-01

    The binding energy of the deuteron was measured and it was determined the neutron mass starting from the nuclear reaction, 1 0 n + 1 1 H → 2 1 D + γ. The produced photon is soon a gamma ray that is emitted when the hydrogen captures a thermal neutron. The photon energy was measured using two spectrometric systems for gamma rays. A system with a detector of NaI(TI) of 3'' x 3'' and the other one with a High-purity Germanium detector. The first detector has a bigger efficiency and a smaller resolution in comparison with the second detector. The energy of the measured photon is the binding energy of the deuteron. With the measurement of the photon energy and the masses of the proton and of the deuterium it was determined the neutron mass. The value of the mass obtained with both systems it was compared with the value reported in the literature. The nuclear reaction was induced in a volume of paraffin that it was bombing with a source 239 PuBe whose activity is of 3.7 x 10 10 Bq. (Author)

  13. Isotopic neutron sources for neutron activation analysis

    International Nuclear Information System (INIS)

    Hoste, J.

    1988-06-01

    This User's Manual is an attempt to provide for teaching and training purposes, a series of well thought out demonstrative experiments in neutron activation analysis based on the utilization of an isotopic neutron source. In some cases, these ideas can be applied to solve practical analytical problems. 19 refs, figs and tabs

  14. International Neutron Radiography Newsletter

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw

    1986-01-01

    At the First World Conference on Neutron Radiography i t was decided to continue the "Neutron Radiography Newsletter", published previously by J.P. Barton, as the "International Neutron Radiography Newsletter" (INRNL), with J.C. Doraanus as editor. The British Journal of Non-Destructive Testing...

  15. Spallation neutron sources

    International Nuclear Information System (INIS)

    Fraser, J.S.; Bartholomew, G.A.

    1983-01-01

    The principles and theory of spallation neutron sources are outlined and a comparison is given with other types of neutron source. A summary of the available accelerator types for spallation neutron sources and their advantages and disadvantages is presented. Suitable target materials are discussed for specific applications, and typical target assemblies shown. (U.K.)

  16. Advances in neutron tomography

    Indian Academy of Sciences (India)

    Up to now the interaction of the neutron spin with magnetic fields in samples has not been applied to imaging techniques despite the fact that it was proposed many years ago. About ten years ago neutron depolarization as imaging signal for neutron radiography or tomography was demonstrated and in principle it works.

  17. Fundamental neutron physics

    International Nuclear Information System (INIS)

    Deslattes, R.; Dombeck, T.; Greene, G.; Ramsey, N.; Rauch, H.; Werner, S.

    1984-01-01

    Fundamental physics experiments of merit can be conducted at the proposed intense neutron sources. Areas of interest include: neutron particle properties, neutron wave properties, and fundamental physics utilizing reactor produced γ-rays. Such experiments require intense, full-time utilization of a beam station for periods ranging from several months to a year or more

  18. Prototype Neutron Energy Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Mitchell, Sanjoy Mukhopadhyay, Richard Maurer, Ronald Wolff

    2010-06-16

    The project goals are: (1) Use three to five pressurized helium tubes with varying polyethylene moderators to build a neutron energy spectrometer that is most sensitive to the incident neutron energy of interest. Neutron energies that are of particular interest are those from the fission neutrons (typically around 1-2 MeV); (2) Neutron Source Identification - Use the neutron energy 'selectivity' property as a tool to discriminate against other competing processes by which neutrons are generated (viz. Cosmic ray induced neutron production [ship effect], [a, n] reactions); (3) Determine the efficiency as a function of neutron energy (response function) of each of the detectors, and thereby obtain the composite neutron energy spectrum from the detector count rates; and (4) Far-field data characterization and effectively discerning shielded fission source. Summary of the presentation is: (1) A light weight simple form factor compact neutron energy spectrometer ready to be used in maritime missions has been built; (2) Under laboratory conditions, individual Single Neutron Source Identification is possible within 30 minutes. (3) Sources belonging to the same type of origin viz., (a, n), fission, cosmic cluster in the same place in the 2-D plot shown; and (4) Isotopes belonging to the same source origin like Cm-Be, Am-Be (a, n) or Pu-239, U-235 (fission) do have some overlap in the 2-D plot.

  19. Neutron detection and radiography

    International Nuclear Information System (INIS)

    Bollen, R.H.; Van Esch, R.F.

    1975-01-01

    An improved method of recording neutron images is described which comprises imagewise irradiating with neutrons an intensifying screen containing a gadolinium compound that fluoresces when struck by x-rays and subjecting the fluorescent light pattern resulting from the impact of the neutrons on the screen onto a photographic material. (auth)

  20. Dual gamma/neutron directional elpasolite detector

    Science.gov (United States)

    Guss, Paul; Mukhopadhyay, Sanjoy

    2013-09-01

    Some applications, particularly in homeland security, require detection of both neutron and gamma radiation. Typically, this is accomplished with a combination of two detectors registering neutrons and gammas separately. We have investigated a new type of neutron/gamma (n/γ) directional detection capability. We explored a new class of scintillator, cerium (Ce)-doped Elpasolites such as Cs2LiYCl6:Ce (CLYC), Cs2LiLaCl6 (CLLC), Cs2LiLaBr6:Ce (CLLB), or Cs2LiYBr6:Ce (CLYB). These materials are capable of providing energy resolution as good as 2.9% at 662 keV (FWHM), which is better than that of NaI:Tl. Because they contain 6Li, Elpasolites can also detect thermal neutrons. In the energy spectra, the full energy thermal neutron peak appears near or above 3 GEEn MeV. Thus, very effective pulse height discrimination is possible. In addition, the core-to-valence luminescence (CVL) provides Elpasolites with different temporal responses under gamma and neutron excitation, and, therefore, may be exploited for effective pulse shape discrimination. For instance, the CLLC emission consists of two main components: (1) CVL spanning from 220 nm to 320 nm and (2) Ce emission found in the range of 350 to 500 nm. The former emission is of particular interest because it appears only under gamma excitation. It is also very fast, decaying with a 2 ns time constant. The n/γ discrimination capability of Elpasolite detectors may be optimized by tuning the cerium doping content for maximum effect on n/γ pulse shape differences. The resulting Elpasolite detectors have the ability to collect neutron and gamma data simultaneously, with excellent discrimination. Further, an array of four of these Elpasolites detectors will perform directional detection in both the neutron and gamma channels simultaneously.

  1. Dual Gamma Neutron Directional Elpasolite Detector

    Energy Technology Data Exchange (ETDEWEB)

    Guss, P. P.; Mukhopadhyay, S.

    2013-09-01

    Some applications, particularly in homeland security, require detection of both neutron and gamma radiation. Typically, this is accomplished with a combination of two detectors registering neutrons and gammas separately. We have investigated a new type of neutron/gamma (n/γ) directional detection capability. We explored a new class of scintillator, cerium (Ce)-doped Elpasolites such as Cs2LiYCl6:Ce (CLYC), Cs2LiLaCl6 (CLLC), Cs2LiLaBr6:Ce (CLLB), or Cs2LiYBr6:Ce (CLYB). These materials are capable of providing energy resolution as good as 2.9% at 662 keV (FWHM), which is better than that of NaI:Tl. Because they contain 6Li, Elpasolites can also detect thermal neutrons. In the energy spectra, the full energy thermal neutron peak appears near or above 3 GEEn MeV. Thus, very effective pulse height discrimination is possible. In addition, the core-to-valence luminescence (CVL) provides Elpasolites with different temporal responses under gamma and neutron excitation, and, therefore, may be exploited for effective pulse shape discrimination. For instance, the CLLC emission consists of two main components: (1) CVL spanning from 220 nm to 320 nm and (2) Ce emission found in the range of 350 to 500 nm. The former emission is of particular interest because it appears only under gamma excitation. It is also very fast, decaying with a 2 ns time constant. The n/γ discrimination capability of Elpasolite detectors may be optimized by tuning the cerium doping content for maximum effect on n/γ pulse shape differences. The resulting Elpasolite detectors have the ability to collect neutron and gamma data simultaneously, with excellent discrimination. Further, an array of four of these Elpasolites detectors will perform directional detection in both the neutron and gamma channels simultaneously.

  2. Neutron scatter camera

    Science.gov (United States)

    Mascarenhas, Nicholas; Marleau, Peter; Brennan, James S.; Krenz, Kevin D.

    2010-06-22

    An instrument that will directly image the fast fission neutrons from a special nuclear material source has been described. This instrument can improve the signal to background compared to non imaging neutron detection techniques by a factor given by ratio of the angular resolution window to 4.pi.. In addition to being a neutron imager, this instrument will also be an excellent neutron spectrometer, and will be able to differentiate between different types of neutron sources (e.g. fission, alpha-n, cosmic ray, and D-D or D-T fusion). Moreover, the instrument is able to pinpoint the source location.

  3. Grazing Incidence Neutron Optics

    Science.gov (United States)

    Gubarev, Mikhail V. (Inventor); Ramsey, Brian D. (Inventor); Engelhaupt, Darell E. (Inventor)

    2013-01-01

    Neutron optics based on the two-reflection geometries are capable of controlling beams of long wavelength neutrons with low angular divergence. The preferred mirror fabrication technique is a replication process with electroform nickel replication process being preferable. In the preliminary demonstration test an electroform nickel optics gave the neutron current density gain at the focal spot of the mirror at least 8 for neutron wavelengths in the range from 6 to 20.ANG.. The replication techniques can be also be used to fabricate neutron beam controlling guides.

  4. Neutron scattering. Experiment manuals

    Energy Technology Data Exchange (ETDEWEB)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner (eds.)

    2010-07-01

    The following topics are dealt with: The thermal triple axis spectrometer PUMA, the high-resolution powder diffractometer SPODI, the hot single-crystal diffractometer HEiDi for structure analysis with neutrons, the backscattering spectrometer SPHERES, neutron polarization analysis with tht time-of-flight spectrometer DNS, the neutron spin-echo spectrometer J-NSE, small-angle neutron scattering with the KWS-1 and KWS-2 diffractometers, the very-small-angle neutron scattering diffractrometer with focusing mirror KWS-3, the resonance spin-echo spectrometer RESEDA, the reflectometer TREFF, the time-of-flight spectrometer TOFTOF. (HSI)

  5. Neutron scattering. Experiment manuals

    International Nuclear Information System (INIS)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

    2010-01-01

    The following topics are dealt with: The thermal triple axis spectrometer PUMA, the high-resolution powder diffractometer SPODI, the hot single-crystal diffractometer HEiDi for structure analysis with neutrons, the backscattering spectrometer SPHERES, neutron polarization analysis with tht time-of-flight spectrometer DNS, the neutron spin-echo spectrometer J-NSE, small-angle neutron scattering with the KWS-1 and KWS-2 diffractometers, the very-small-angle neutron scattering diffractrometer with focusing mirror KWS-3, the resonance spin-echo spectrometer RESEDA, the reflectometer TREFF, the time-of-flight spectrometer TOFTOF. (HSI)

  6. Neutron scattering. Experiment manuals

    International Nuclear Information System (INIS)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

    2012-01-01

    The following topics are dealt with: The thermal triple-axis spectrometer PUMA, the high-resolution powder diffractometer SPODI, the hot single-crystal diffractometer HEiDi for structure analysis with neutrons, the backscattering spectrometer SPHERES, the neutron polarization analyzer DNS, the neutron spin-echo spectrometer J-NSE, the small-angle neutron diffractometers KWS-1/-2, the very-small-angle neutron diffractometer with focusing mirror KWS-3, the resonance spin-echo spectrometer RESEDA, the reflectometer TREFF, the time-of-flight spectrometer TOFTOF. (HSI)

  7. Semiconductor neutron detector

    Science.gov (United States)

    Ianakiev, Kiril D [Los Alamos, NM; Littlewood, Peter B [Cambridge, GB; Blagoev, Krastan B [Arlington, VA; Swinhoe, Martyn T [Los Alamos, NM; Smith, James L [Los Alamos, NM; Sullivan, Clair J [Los Alamos, NM; Alexandrov, Boian S [Los Alamos, NM; Lashley, Jason Charles [Santa Fe, NM

    2011-03-08

    A neutron detector has a compound of lithium in a single crystal form as a neutron sensor element. The lithium compound, containing improved charge transport properties, is either lithium niobate or lithium tantalate. The sensor element is in direct contact with a monitor that detects an electric current. A signal proportional to the electric current is produced and is calibrated to indicate the neutrons sensed. The neutron detector is particularly useful for detecting neutrons in a radiation environment. Such radiation environment may, e.g. include gamma radiation and noise.

  8. Nanosecond neutron generator

    International Nuclear Information System (INIS)

    Lobov, S.I.; Pavlovskaya, N.G.; Pukhov, S.P.

    1991-01-01

    High-voltage nanosecond neutron generator for obtaining neutrons in D-T reaction is described. Yield of 6x10 6 neutron/pulse was generated in a sealed gas-filled diode with a target on the cathode by accelerating pulse voltage of approximately 0.5 MV and length at half-height of 0.5 ns and deuterium pressure of 6x10 -2 Torr. Ways of increasing neutron yield and possibilities of creating generators of nanosecond neutron pulses with great service life are considered

  9. Activation neutron detector

    International Nuclear Information System (INIS)

    Ambardanishvili, T.S.; Kolomiitsev, M.A.; Zakharina, T.Y.; Dundua, V.J.; Chikhladze, N.V.

    1976-01-01

    An activation neutron detector made as a moulded and cured composition of a material capable of being neutron-activated is described. The material is selected from a group consisting of at least two chemical elements, a compound of at least two chemical elements and their mixture, each of the chemical elements and their mixture, each of the chemical elements being capable of interacting with neutrons to form radioactive isotopes having different radiation energies when disintegrating. The material capable of being neutron-activated is distributed throughout the volume of a polycondensation resin inert with respect to neutrons and capable of curing. 17 Claims, No Drawings

  10. A high pressure apparatus for neutron diffraction

    International Nuclear Information System (INIS)

    Kamigaki, Kazuo; Yoshida, Hajime; Ohashi, Masayoshi; Kaneko, Takejiro; Sato, Kozaburo.

    1980-01-01

    A high pressure apparatus was developed for thermal neutron diffraction of time-of-flight method. The high pressure vessel was a piston-cylinder type, and Ti-Zr alloy was used as a material of the cylinder. The coherent scattering of neutron is suppressed in Ti-53wt% Zr alloy. The diffraction spectrum is formed of peaks from the specimen and a background, which corresponds to the energy distribution of the incident neutron. High pressure measurements were made in RbBr on the transformation between NaCl-type structure and CsCl-type to a pressure about 20 kb, and a good agreement was confirmed with former experiments. (author)

  11. Neutron elastic and inelastic cross section measurements for 28Si

    Science.gov (United States)

    Derdeyn, E. C.; Lyons, E. M.; Morin, T.; Hicks, S. F.; Vanhoy, J. R.; Peters, E. E.; Ramirez, A. P. D.; McEllistrem, M. T.; Mukhopadhyay, S.; Yates, S. W.

    2017-09-01

    Neutron elastic and inelastic cross sections are critical for design and implementation of nuclear reactors and reactor equipment. Silicon, an element used abundantly in fuel pellets as well as building materials, has little to no experimental cross sections in the fast neutron region to support current theoretical evaluations, and thus would benefit from any contribution. Measurements of neutron elastic and inelastic differential scattering cross sections for 28Si were performed at the University of Kentucky Accelerator Laboratory for incident neutron energies of 6.1 MeV and 7.0 MeV. Neutrons were produced by accelerated deuterons incident on a deuterium gas cell. These nearly mono-energetic neutrons then scattered off a natural Si sample and were detected using liquid deuterated benzene scintillation detectors. Scattered neutron energy was deduced using time-of-flight techniques in tandem with kinematic calculations for an angular distribution. The relative detector efficiency was experimentally determined over a neutron energy range from approximately 0.5 to 7.75 MeV prior to the experiment. Yields were corrected for multiple scattering and neutron attenuation in the sample using the forced-collision Monte Carlo correction code MULCAT. Resulting cross sections will be presented along with comparisons to various data evaluations. Research is supported by USDOE-NNSA-SSAP: NA0002931, NSF: PHY-1606890, and the Donald A. Cowan Physics Institute at the University of Dallas.

  12. Elastic and Inelastic Scattering of Neutrons using a CLYC array

    Science.gov (United States)

    Brown, Tristan; Doucet, E.; Chowdhury, P.; Lister, C. J.; Wilson, G. L.; Devlin, M.; Mosby, S.

    2015-10-01

    CLYC scintillators, which have dual neutron and gamma response, have recently ushered in the possibility of fast neutron spectroscopy without time-of-flight (TOF). A 16-element array of 1'' x 1'' 6Li-depleted CLYC crystals, where pulse-shape-discrimination is achieved via digital pulse processing, has been commissioned at UMass Lowell. In an experiment at LANSCE, high energy neutrons were used to bombard 56Fe and 238U targets, in order to measure elastic and inelastic neutron scattering cross sections as a function of energy and angle with the array. The array is placed very close to the targets for enhanced geometrical solid angles for scattered neutrons compared to standard neutron-TOF measurements. A pulse-height spectrum of scattered neutrons in the detectors is compared to the energy of the incident neutrons, which is measured via the TOF of the pulsed neutrons from the source to the detectors. Recoil corrections are necessary to combine the energy spectra from all the detectors to obtain angle-integrated elastic and inelastic cross-sections. The detection techniques, analysis procedures and results will be presented. Supported by NNSA-SSAA program through DOE Grant DE-NA00013008.

  13. Thermal neutron moderating device

    International Nuclear Information System (INIS)

    Takigami, Hiroyuki.

    1995-01-01

    In a thermal neutron moderating device, superconductive coils for generating magnetic fields capable of applying magnetic fields vertical to the longitudinal direction of a thermal neutron passing tube, and superconductive coils for magnetic field gradient for causing magnetic field gradient in the longitudinal direction of the thermal neutron passing tube are disposed being stacked at the outside of the thermal neutron passing tube. When magnetic field gradient is present vertically to the direction of a magnetic moment, thermal neutrons undergo forces in the direction of the magnetic field gradient in proportion to the magnetic moment. Then, the magnetic moment of the thermal neutrons is aligned with the direction vertical to the passing direction of the thermal neutrons, to cause the magnetic field gradient in the passing direction of the thermal neutrons. The speed of the thermal neutrons can be optionally selected and the wavelength can freely be changed by applying forces to the thermal neutrons and changing the extent and direction of the magnetic field gradient. Superconductive coils are used as the coils for generating magnetic fields and the magnetic field gradient in order to change extremely high energy of the thermal neutrons. (N.H.)

  14. Neutron structural biology

    Energy Technology Data Exchange (ETDEWEB)

    Niimura, Nobuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Neutron diffraction provides an experimental method of directly locating hydrogen atoms in protein which play important roles in physiological functions. However, there are relatively few examples of neutron crystallography in biology since it takes a lot of time to collect a sufficient number of Bragg reflections due to the low flux of neutrons illuminating the sample. In order to overcome the flux problem, we have successfully developed the neutron IP, where the neutron converter, {sup 6}Li or Gd, was mixed with a photostimulated luminescence material on flexible plastic support. Neutron Laue diffraction 2A data from tetragonal lysozyme were collected for 10 days with neutron imaging plates, and 960 hydrogen atoms in the molecule and 157 bound water molecules were identified. These results explain the proposed hydrolysis mechanism of the sugar by the lysozyme molecule and that lysozyme is less active at pH7.0. (author)

  15. Atlas of neutron resonances

    CERN Document Server

    Mughabghab, Said

    2018-01-01

    Atlas of Neutron Resonances: Resonance Properties and Thermal Cross Sections Z= 1-60, Sixth Edition, contains an extensive list of detailed individual neutron resonance parameters for Z=1-60, as well as thermal cross sections, capture resonance integrals, average resonance parameters and a short survey of the physics of thermal and resonance neutrons. The long introduction contains: nuclear physics formulas aimed at neutron physicists; topics of special interest such as valence neutron capture, nuclear level density parameters, and s-, p-, and d-wave neutron strength functions; and various comparisons of measured quantities with the predictions of nuclear models, such as the optical model. As in the last edition, additional features have been added to appeal to a wider spectrum of users. These include: spin-dependent scattering lengths that are of interest to solid-state physicists, nuclear physicists and neutron evaluators; calculated and measured Maxwellian average 5-keV and 30-keV capture cross sections o...

  16. Neutron image intensifier tubes

    International Nuclear Information System (INIS)

    Verat, M.; Rougeot, H.; Driard, B.

    1983-01-01

    The most frequently used techniques in neutron radiography employ a neutron converter consisting of either a scintillator or a thin metal sheet. The radiation created by the neutrons exposes a photographic film that is in contact with the converter: in the direct method, the film is exposed during the time that the object is irradiated with neutrons; in the transfer method, the film is exposed after the irradiation of the object with neutrons. In industrial non-destructive testing, when many identical objects have to be checked, these techniques have several disadvantages. Non-destructive testing systems without these disadvantages can be constructed around neutron-image intensifier tubes. A description and the operating characteristics of neutron-image intensifier tubes are given. (Auth.)

  17. Neutrons as a probe

    International Nuclear Information System (INIS)

    Iizumi, Masashi

    1993-01-01

    As an introduction to the symposium a brief overview will be given about the features of neutrons as a probe. First it will be pointed out that the utilization of neutrons as a probe for investigating the structural and dynamical properties of condensed matters is a benign gift eventuated from the release of atomic energy initiated by Enrico Fermi exactly half century ago. Features of neutrons as a probe are discussed in accordance with the four basic physical properties of neutrons as an elementary particle; (1) no electric charge (the interaction with matter is nuclear), (2) the mass of neutron is 1 amu, (3) spin is 1/2 and (4) neutrons have magnetic dipole moment. Overview will be given on the uniqueness of neutrons as a probe and on the variety in the way they are used in the wide research area from the pure science to the industrial applications. (author)

  18. Methods of neutron spectrometry

    International Nuclear Information System (INIS)

    Doerschel, B.

    1981-01-01

    The different methods of neutron spectrometry are based on the direct measurement of neutron velocity or on the use of suitable energy-dependent interaction processes. In the latter case the measuring effect of a detector is connected with the searched neutron spectrum by an integral equation. The solution needs suitable unfolding procedures. The most important methods of neutron spectrometry are the time-of-flight method, the crystal spectrometry, the neutron spectrometry by use of elastic collisions with hydrogen nuclei, and neutron spectrometry with the aid of nuclear reactions, especially of the neutron-induced activation. The advantages and disadvantages of these methods are contrasted considering the resolution, the measurable energy range, the sensitivity, and the experimental and computational efforts. (author)

  19. Neutron source for generating fast neutrons

    International Nuclear Information System (INIS)

    Schraube, H.; Morhart, A.

    1980-01-01

    In radiotherapeutics, neutron sources are needed, generating a dose rate as high as possible and neutrons as energetic as possible. By bombardment of tritium targets with deuterons of some 100 keV, neutrons of about 15 MeV are produced, but because of the large slow-down effect in the target consisting of heavy metal the yield is too small. On applying beryllium targets the neutron yields are too small below a deuteron energy of 15 MeV; at the same time, the high percentage of low energy neutrons is undesirable. Based on the favorable yield of the D(d,n) He 3 reaction for deuterons of about 100 MeV, a gas-target chamber is designed. The pressure chamber is designed for a deuterium pressure of up to 11 atmospheres and provided with cooling devices. The flux density in beam direction at a distance of 1 m reaches 108 per cm 2 , the maximum energy of the neutrons amounts to 12 MeV at deuteron energies of 9 MeV, and the neutron share below 9 MeV is small. The maximum dose rate in a tissue-equivalent phantom lies at 40 rads/min. (orig./PW)

  20. Neutron microscope with refractive wedge

    International Nuclear Information System (INIS)

    Masalovich, S.V.

    1990-01-01

    A possibility of applying a refractive element in a mirror-neutron microscope using ultracold neutrons to reduce neutron aberrations is considered. Application of a refractive element in a neutron microscope with horizontal optical axis is studied. A scheme of neutron microscope with a refractive wedge is presented, evaluation of quartz wedge parameters is made. It is stressed that application of refractive elements in neutron microscopes facilitates aberration reduction in neutron-optical systems

  1. Fast Neutron Dose Distribution in a Linac Radiotherapy Facility

    International Nuclear Information System (INIS)

    Al-Othmany, D.Sh.; Abdul-Majid, S.; Kadi, M.W.

    2011-01-01

    CR-39 plastic detectors were used for fast neutron dose mapping in the radiotherapy facility at King AbdulAziz University Hospital (KAUH). Detectors were calibrated using a 252 Cf neutron source and a neutron dosimeter. After exposure chemical etching was performed using 6N NaOH solution at 70 degree C. Tracks were counted using an optical microscope and the number of tracks/cm 2 was converted to a neutron dose. 15 track detectors were distributed inside and outside the therapy room and were left for 32 days. The average neutron doses were 142.3 mSv on the accelerator head, 28.5 mSv on inside walls, 1.4 mSv beyond the beam shield, and 1 mSv in the control room

  2. Accidental fast neutron dosimetry by means of plastic identity cards

    International Nuclear Information System (INIS)

    Lommler, B.; Pitt, E.; Scharmann, A.; Simmer, R.

    1991-01-01

    Identity cards designed to provide high security against falsification are often composed of polymeric compounds and a paper-like inlay containing the identifying information. This system may be considered as a fast neutron detector when certain boundary conditions, especially concerning the polymer are fulfilled. The track recording properties of the plastic envelope of a widely used identity card were investigated. Recoil tracks induced by fast neutrons were revealed by electrochemical etching in 5N NaOH in a thin cover mounted on a trick etch-resistant base. The etching parameters (etchant normality, temperature, time, field strength, frequency) were optimized to achieve maximum neutron sensitivity. The response for neutrons from a CF 252 source is about one per cent of that of the widely used CR-39 track detector material. The possible use of the identity card as an etch track detector in accidental neutron dosimetry is discussed. (author)

  3. A large animal model for boron neutron capture therapy

    International Nuclear Information System (INIS)

    Gavin, P.R.; Kraft, S.L.; DeHaan, C.E.; Moore, M.P.; Griebenow, M.L.

    1992-01-01

    An epithermal neutron beam is needed to treat relatively deep seated tumors. The scattering characteristics of neutrons in this energy range dictate that in vivo experiments be conducted in a large animal to prevent unacceptable total body irradiation. The canine species has proven an excellent model to evaluate the various problems of boron neutron capture utilizing an epithermal neutron beam. This paper discusses three major components of the authors study: (1) the pharmacokinetics of borocaptate sodium (NA 2 B 12 H 11 SH or BSH) in dogs with spontaneously occurring brain tumors, (2) the radiation tolerance of normal tissues in the dog using an epithermal beam alone and in combination with borocaptate sodium, and (3) initial treatment of dogs with spontaneously occurring brain tumors utilizing borocaptate sodium and an epithermal neutron beam

  4. Radioisotopes produced by neutron irradiation of food.

    Science.gov (United States)

    Albright, S; Seviour, R

    2016-04-01

    The use of neutrons for cargo interrogation has the potential to drastically improve threat detection. Previous research has focussed on the production of (24)Na, based on the isotopes produced in pharmaceuticals and medical devices. For both the total activity and the ingestion dose we show that a variety of isotopes contribute and that (24)Na is only dominant under certain conditions. The composition of the foods has a strong influence on the resulting activity and ingestion dose suggesting that the pharmaceuticals and medical devices considered initially are not a viable analogue for foodstuffs. There is an energy dependence to the isotopes produced due to the cross-sections of different reactions varying with neutron energy. We show that this results in different isotopes dominating the ingestion dose at different energies, which has not been considered in the previous literature. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. NEUTRON DENSITY CONTROL IN A NEUTRONIC REACTOR

    Science.gov (United States)

    Young, G.J.

    1959-06-30

    The method and means for controlling the neutron density in a nuclear reactor is described. It describes the method and means for flattening the neutron density distribution curve across the reactor by spacing the absorbing control members to varying depths in the central region closer to the center than to the periphery of the active portion of the reactor to provide a smaller neutron reproduction ratio in the region wherein the members are inserted, than in the remainder of the reactor thereby increasing the over-all potential power output.

  6. Artefacts of fast neutron radiography concerned with neutron scattering

    International Nuclear Information System (INIS)

    Mikerov, V.I.; Isakov, A.I.; Tukarev, V.A.; Koshelev, A.P.; Bykov, A.A.; Khodeev, A.I.; Waschkowski, W.

    1999-01-01

    The paper considers peculiarities of fast neutron radiography with a two dimensional detector. Effects produced by scattered neutrons was simulated for various neutron sources. Contribution of γ-rays generated in the sample was estimated for a fission spectrum of fast neutrons. Feasibility of fast neutrons collimating by a honeycomb collimator was considered.(author)

  7. The use of neutron diffraction for the determination of the in-depth residual stresses profile in weld coatings; A utilizacao da difracao de neutroes na determinacao do perfil de tensoes residuais em revestimentos por soldadura

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Maria Jose; Batista, A.C.; Nobre, J.P. [Universidade de Coimbra (Portugal). Dept. de Fisica. Centro de Estudos de Materiais por Difraccao de Raios X (CEMDRX); Loureiro, Altino [Universidade de Coimbra (Portugal). Dept. de Engenharia Mecanica. Centro de Engenharia Mecanica (CEMUC); Kornmeier, Joana R., E-mail: mjvaz@fe.up.pt [Technische Universitaet Muenchen, Garching (Germany). FRM II

    2013-04-15

    The neutron diffraction is a non-destructive technique, particularly suitable for the analysis of residual stress fields in welds. The technique is used in this article to study ferritic samples, coated by submerged arc welding using stainless steel filler metals. This procedure is often used for manufacturing process equipment for chemical and nuclear industries, for ease of implementation and economic reasons. The main disadvantage of that processes is the cracking phenomenon that often occurs at the interface between the base material and coatings, which can be minimized by performing post-weld stress relief heat treatments. The samples analyzed in this study were made of carbon steel plates, coated by submerged arc welding two types of stainless steel filler metals. For the first layer was used one EN 12 072 - S 2 U 23 12 electrode, while for the second and third layers were used an EN 12 072 - 19 12 3 S L electrode. After cladding, the samples were submitted to a post-weld heat treatment for 1 hour at 620 deg C. The residual stress profiles obtained by neutron diffraction evidence the relaxation of residual stress given by the heat treatment. (author)

  8. Neutron and x-ray scattering study of phonon dispersion and diffuse scattering in (Na ,Bi ) Ti O3-x BaTi O3 single crystals near the morphotropic phase boundary

    Science.gov (United States)

    Luo, Chengtao; Bansal, Dipanshu; Li, Jiefang; Viehland, Dwight; Winn, Barry; Ren, Yang; Li, Xiaobing; Luo, Haosu; Delaire, Olivier

    2017-11-01

    Neutron and x-ray scattering measurements were performed on (N a1 /2B i1 /2 ) Ti O3-x at %BaTi O3 (NBT-x BT ) single crystals (x =4 , 5, 6.5, and 7.5) across the morphotropic phase boundary (MPB), as a function of both composition and temperature, and probing both structural and dynamical aspects. In addition to the known diffuse scattering pattern near the Γ points, our measurements revealed new, faint superlattice peaks, as well as an extensive diffuse scattering network, revealing a short-range ordering of polar nanoregions (PNR) with a static stacking morphology. In samples with compositions closest to the MPB, our inelastic neutron scattering investigations of the phonon dynamics showed two unusual features in the acoustic phonon branches, between the superlattice points, and between the superlattice points and Γ points, respectively. These critical elements are not present in the other compositions away from the MPB, which suggests that these features may be related to the tilt modes coupling behavior near the MPB.

  9. Pulsed neutron porosity logging system

    International Nuclear Information System (INIS)

    Smith, H.D. Jr.; Smith, M.P.; Schultz, W.E.

    1978-01-01

    An improved pulsed neutron porosity logging system is provided in the present invention. A logging tool provided with a 14 MeV pulsed neutron source, an epithermal neutron detector, and a fast neutron detector is moved through a borehole. Repetitive bursts of neutrons irradiate the earth formations and, during the bursts, the fast neutron population is sampled. During the interval between bursts the epithermal neutron population is sampled along with background gamma radiation due to lingering thermal neutrons. The fast and epithermal neutron population measurements are combined to provide a measurement of formation porosity

  10. Nuclear spectroscopy using the neutron capture reaction

    International Nuclear Information System (INIS)

    Egidy, T.

    1982-01-01

    Experimental methods using neutron spectroscopy as a means to study the nucleus structure are described. Since reactions of neutron capture (n, γ) are non-selective, they permit to study the nature of excitation (monoparticle and collective) of nuclear levels, the nature of vibrational excitations, to check the connection between shell model and liquid drop model etc. In many cases (n, γ) reactions are the only way to check the forecast of nuclear models. Advantages of (n, γ) spectroscopy, possessing a high precision of measurement and high sensitivity, are underlined. Using neutron spectroscopy on facilities with a high density of neutron flux the structures of energy levels of a large group of nuclei are studied. In different laboratories complete schemes of energy levels of nuclei are obtained, a great number of new levels are found, the evergy level densities are determined, multipolarities of γ-transitions, spins, level parities are considered. StrUctures of rotational bands of heavy deformed nuclei are studied. The study of the structure of high-spin states is possible only using the methods of (n, γ) spectroscopy Investigation results of the nuclei 24 Na, 114 Cd, 154 Eu, 155 Cd, 155 Sm, 233 Th are considered as examples. The most interesting aspects of the investigations using neutron spectroscopy are discUssed

  11. A polarizing neutron periscope for neutron imaging

    International Nuclear Information System (INIS)

    Schulz, Michael; Boeni, Peter; Calzada, Elbio; Muehlbauer, Martin; Neubauer, Andreas; Schillinger, Burkhard

    2009-01-01

    Optical neutron polarizers like guides or benders destroy the collimation of a neutron beam due to multiple reflections or scattering. This makes them unsuitable for their use in polarized neutron radiography, because the beam collimation is essential to obtain high spatial resolution. We have developed a neutron polarizer based on the principle of an optical periscope with a zigzag double reflection on two parallel high-m supermirror polarizers. If the supermirrors are perfectly parallel and flat, the beam collimation is left unchanged by such a device. A first proof of concept version of this type of polarizer was built and tested. We expect to achieve a beam polarization of up to 99% with an improved version yet to be built.

  12. A polarizing neutron periscope for neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Michael [FRM II, Lichtenbergstr. 1, 85748 Garching (Germany); Technische Universitaet Muenchen, Physik Department E21, James Franck Strasse, 85748 Garching (Germany)], E-mail: Michael.Schulz@frm2.tum.de; Boeni, Peter [Technische Universitaet Muenchen, Physik Department E21, James Franck Strasse, 85748 Garching (Germany); Calzada, Elbio; Muehlbauer, Martin [FRM II, Lichtenbergstr. 1, 85748 Garching (Germany); Technische Universitaet Muenchen, Physik Department E21, James Franck Strasse, 85748 Garching (Germany); Neubauer, Andreas [Technische Universitaet Muenchen, Physik Department E21, James Franck Strasse, 85748 Garching (Germany); Schillinger, Burkhard [FRM II, Lichtenbergstr. 1, 85748 Garching (Germany); Technische Universitaet Muenchen, Physik Department E21, James Franck Strasse, 85748 Garching (Germany)

    2009-06-21

    Optical neutron polarizers like guides or benders destroy the collimation of a neutron beam due to multiple reflections or scattering. This makes them unsuitable for their use in polarized neutron radiography, because the beam collimation is essential to obtain high spatial resolution. We have developed a neutron polarizer based on the principle of an optical periscope with a zigzag double reflection on two parallel high-m supermirror polarizers. If the supermirrors are perfectly parallel and flat, the beam collimation is left unchanged by such a device. A first proof of concept version of this type of polarizer was built and tested. We expect to achieve a beam polarization of up to 99% with an improved version yet to be built.

  13. Neutron wave optics studied with ultracold neutrons

    International Nuclear Information System (INIS)

    Steyerl, A.

    1984-01-01

    The author discusses experiments demonstrating or utilizing the wave properties of neutrons with wavelengths of about 100 nm. In particular the 'UCN gravity diffractometer' and the gravity spectrometer NESSIE (Neutronen-Schwerkraft-Spectrometrie) are illustrated. (Auth.)

  14. Status of spallation neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Oyama, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    Existing and planned facilities using proton accelerator driven spallation neutron source are reviewed. These include new project of neutron science proposed from Japan Atomic Energy Research Institute. The present status of facility requirement and accelerator technology leads us to new era of neutron science such as neutron scattering research and nuclear transmutation study using very intense neutron source. (author)

  15. Shape transition in the neutron rich sodium isotopes

    International Nuclear Information System (INIS)

    Campi, X.; Flocard, H.; Kerman, A.K.; Koonin, S.; Massachusetts Inst. of Tech., Cambridge

    1975-06-01

    Mass spectrometer measurements of the neutron rich sodium isotopes show a sudden increase at 31 Na in the values of the two neutron separation energies. The spherical shell model naturally predicts a sudden decrease at 32 Na after the N=20 shell closure. It is proposed that the explanation for this disagreement lies in the fact that sodium isotopes in this mass region are strongly deformed due to the filling of negative parity orbitals from the 1fsub(7/2) shell. Hartree-Fock calculations are presented in support of this conjecture [fr

  16. Precision neutron polarimetry for neutron beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Penttila, S. I. (Seppo I.); Bowman, J. D. (J. David)

    2004-01-01

    The abBA collaboration is developing a new type of field-expansion spectrometer for measurement of the three correlation coefficients a, A, and B and shape parameter b. The measurement of A and B requires precision neutron polarimetry. We will polarize a pulsed cold neutron beam from SNS using a {sup 3}He neutron spin filter. The well-known polarizing cross section for n-{sup 3}He has 1/v dependence, which is used to determine the absolute beam polarization through a time-of-flight (TOF) measurement. We show that measuring the TOF dependence of A and B, the coefficients and the neutron polarization can be determined with small loss of statistical precision and negligible systematic error. We conclude that it is possible to determine the neutron polarization averaged over a run in the neutron beta decay experiment to better than 10{sup -3}. We discuss various sources of systematic uncertainties in the measurement of A and B and conclude that they are less than 10{sup -4}.

  17. Neutron radiography using neutron imaging plate.

    Science.gov (United States)

    Chankow, Nares; Punnachaiya, Suvit; Wonglee, Sarinrat

    2010-01-01

    The aims of this research are to study properties of a neutron imaging plate (NIP) and to test it for use in nondestructive testing (NDT) of materials. The experiments were carried out by using a BAS-ND 2040 Fuji NIP and a neutron beam from the Thai Research Reactor TRR-1/M1. The neutron intensity and Cd ratio at the specimen position were approximately 9x10(5) ns/cm(2) s and 100 respectively. It was found that the photostimulated luminescence (PSL) readout of the imaging plate was directly proportional to the exposure time and approximately 40 times faster than the conventional NR using Gd converter screen/X-ray film technique. The sensitivities of the imaging plate to slow neutron and to Ir-192 gamma-rays were found to be approximately 4.2x10(-3) PSL/mm(2) per neutron and 6.7x10(-5) PSL/mm(2) per gamma-ray photon respectively. Finally, some specimens containing light elements were selected to be radiographed with neutrons using the NIP and the Gd converter screen/X-ray film technique. The image quality obtained from the two recording media was found to be comparable. Crown Copyright 2009. Published by Elsevier Ltd. All rights reserved.

  18. Precision neutron polarimetry for neutron beta decay

    International Nuclear Information System (INIS)

    Penttila, S.I.; Bowman, J.D.

    2004-01-01

    The abBA collaboration is developing a new type of field-expansion spectrometer for measurement of the three correlation coefficients a, A, and B and shape parameter b. The measurement of A and B requires precision neutron polarimetry. We will polarize a pulsed cold neutron beam from SNS using a 3 He neutron spin filter. The well-known polarizing cross section for n- 3 He has 1/v dependence, which is used to determine the absolute beam polarization through a time-of-flight (TOF) measurement. We show that measuring the TOF dependence of A and B, the coefficients and the neutron polarization can be determined with small loss of statistical precision and negligible systematic error. We conclude that it is possible to determine the neutron polarization averaged over a run in the neutron beta decay experiment to better than 10 -3 . We discuss various sources of systematic uncertainties in the measurement of A and B and conclude that they are less than 10 -4 .

  19. Analysis of some Egyptian cosmetic samples by fast neutron activation analysis

    International Nuclear Information System (INIS)

    Medhat, M.E.; Ali, M.A.; Hassan, M.F.

    2001-01-01

    A description of D-T neutron generator (NG) is presented. This generator can be used for fast neutron activation analysis applied to determine some selected elements, especially light elements, in different materials. The concentrations of the elements Na, Mg, Al, Si, K, Cl, Ca and Fe were determined in two domestic brands of face powder by using 14 MeV neutron activation analysis

  20. Analysis of Some Egyptian Cosmetic Samples by Fast Neutron Activation Analysis

    CERN Document Server

    Medhat, M E; Fayez-Hassan, M

    2001-01-01

    A description of D-T neutron generator (NG) is presented. This generator can be used for fast neutron activation analysis applied to determine some selected elements, especially light elements, in different materials. In our work, the concentration of the elements Na, Mg, Al, Si, K, Cl, Ca and Fe, were determined in two domestic brands of face powder by using 14 MeV neutron activation analysis.

  1. Neutron sources and applications

    Energy Technology Data Exchange (ETDEWEB)

    Price, D.L. [ed.] [Argonne National Lab., IL (United States); Rush, J.J. [ed.] [National Inst. of Standards and Technology, Gaithersburg, MD (United States)

    1994-01-01

    Review of Neutron Sources and Applications was held at Oak Brook, Illinois, during September 8--10, 1992. This review involved some 70 national and international experts in different areas of neutron research, sources, and applications. Separate working groups were asked to (1) review the current status of advanced research reactors and spallation sources; and (2) provide an update on scientific, technological, and medical applications, including neutron scattering research in a number of disciplines, isotope production, materials irradiation, and other important uses of neutron sources such as materials analysis and fundamental neutron physics. This report summarizes the findings and conclusions of the different working groups involved in the review, and contains some of the best current expertise on neutron sources and applications.

  2. Neutron sources and applications

    International Nuclear Information System (INIS)

    Price, D.L.; Rush, J.J.

    1994-01-01

    Review of Neutron Sources and Applications was held at Oak Brook, Illinois, during September 8--10, 1992. This review involved some 70 national and international experts in different areas of neutron research, sources, and applications. Separate working groups were asked to (1) review the current status of advanced research reactors and spallation sources; and (2) provide an update on scientific, technological, and medical applications, including neutron scattering research in a number of disciplines, isotope production, materials irradiation, and other important uses of neutron sources such as materials analysis and fundamental neutron physics. This report summarizes the findings and conclusions of the different working groups involved in the review, and contains some of the best current expertise on neutron sources and applications

  3. Experiments on neutron radiography

    International Nuclear Information System (INIS)

    Abdul Ghaffar Ramli; Azali Muhamad; Wan Ruslan Yusof; Ahmad Sabri Abdul Razak; Jamal Khaer Ibrahim; Rosley Jaafar

    1984-01-01

    This paper presents the neutron-radiography research activities in Nuclear Energy Unit (UTN) as a trial before a neutron-radiography service can routinely be given. This trial neutron-radiography research encompasses the design and construction of a facility (NuR 1), collimator and the exposure system, as well as measurements of neutron and gamma dose-distribution, neutron-beam properties in NuR 1 and characteristics of the image recorder. A few problems arose in the early stage of work and the action taken to overcome these are also mentioned. Finally, methods of increasing the quality of the image are proposed and attempted. This project has given some important information so as to enable the construction of a permanent facility (Nur 2) and the execution of a neutron-radiography service. (author)

  4. Prototype Stilbene Neutron Collar

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, M. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Shumaker, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Snyderman, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Verbeke, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wong, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-10-26

    A neutron collar using stilbene organic scintillator cells for fast neutron counting is described for the assay of fresh low enriched uranium (LEU) fuel assemblies. The prototype stilbene collar has a form factor similar to standard He-3 based collars and uses an AmLi interrogation neutron source. This report describes the simulation of list mode neutron correlation data on various fuel assemblies including some with neutron absorbers (burnable Gd poisons). Calibration curves (doubles vs 235U linear mass density) are presented for both thermal and fast (with Cd lining) modes of operation. It is shown that the stilbene collar meets or exceeds the current capabilities of He-3 based neutron collars. A self-consistent assay methodology, uniquely suited to the stilbene collar, using triples is described which complements traditional assay based on doubles calibration curves.

  5. Biological effects of neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Ogiu, Toshiaki; Ohmachi, Yasushi; Ishida, Yuka [National Inst. of Radiological Sciences, Chiba (JP)] [and others

    2003-03-01

    Although the occasion to be exposed to neutrons is rare in our life, except for nuclear accidents like in the critical accident at Tokai-mura in 1999, countermeasures against accident should be always prepared. In the Tokai-mura accident, residents received less than 21 mSv of neutrons and gamma rays. The cancer risks and fetal effects of low doses of neutrons were matters of concern among residents. The purpose of this program is to investigate the relative biological effectiveness (RBE) for leukemias, and thereby to assess risks of neutrons. Animal experiments are planed to obtain the following RBEs: (1) RBE for the induction of leukemias in mice and (2) RBE for effects on fetuses. Cyclotron fast neutrons (10 MeV) and electrostatic accelerator-derived neutrons (2 MeV) are used for exposure in this program. Furthermore, cytological and cytogenetic analyses will be performed. (author)

  6. Posterior magnetic effect on the pure and doped Fe-Ni alloy under neutron irradiation; Efeito magnetico posterior na liga Fe-Ni pura e dopada, sob irradiacao neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Iris

    1974-07-01

    Polycrystalline specimens of unirradiated and neutron irradiated Fe-Ni alloys have been studied in the temperature range RT - 500 deg C. The study was carried out in pure (50-50) as well as in Si, A1, Cr and Mo doped samples. Initial magnetic permeability was measured in unirradiated (virgin)and in neutron irradiated samples, during isochronal and linear thermal treatments. The main results are: a magnetic After Effect (MAE) is detected in the temperature range 370 deg C - Tc, where Tc is the Curie Temperature. In this range an activation energy of 3.2 {+-} 0.2 eV was determined for the Cr doped Fe-Ni alloy (impurity content: 0.1%); measurements made in the irradiated samples, during a linear temperature treatment, show the existence of several MAE zones in the temperature range RT - Tc. The isochronal annealing experiments show that these MAE zones are accompanied by a decrease in the room temperature value of the magnetic permeability, for zones between RT and a certain temperature T{sub 1}. Above this range there is a steep increase in the room temperature permeability. Activation energies were determined for pure and Mo-doped (0.1%) samples for the first MAE zone (50 deg C - 120 deg C). The values obtained 1.25 - 0.08 eV and 1.42 {+-} 0.09 eV, respectively; the impurity - doped samples show a different behaviour relative to the pure ones: samples with low impurity content (0.1% and 0.5% of Si, Al or Mo) present an enhancement in the amplitude and also an overlapping of the diffusion stages. On the other hand, samples with higher impurity content (2 and 4% of Mo) show a decrease in these amplitudes. (author)

  7. ASIC based neutron monitor

    International Nuclear Information System (INIS)

    Shastrakar, R.S.; Madavi, Vaishali; Chandratre, V.B.; Manna, A.; Jakati, R.K.; Kataria, S.K.; Gopalakrishnan, N.

    2005-01-01

    A Neutron monitor is designed and developed using the OCTPREM, ADAM ASIC and the triplex LCD devices developed by Electronics Division BARC. The Neutron monitor uses BF3 as detector. The Neutron monitor is subdivided into three modules front end pulse processing using the OCTPREM ASIC, H.V. Unit, and the counting display unit using ADAM ASIC. The monitor features low power design and portable. The unit demonstrates the success of the devices developed in Electronics Division BARC. (author)

  8. The Advanced Neutron Source

    International Nuclear Information System (INIS)

    Hayter, J.B.

    1989-01-01

    The Advanced Neutron Source (ANS) is a new user experimental facility planned to be operational at Oak Ridge in the late 1990's. The centerpiece of the ANS will be a steady-state research reactor of unprecedented thermal neutron flux (φ th ∼ 9·10 19 m -2 ·s -1 ) accompanied by extensive and comprehensive equipment and facilities for neutron-based research. 5 refs., 5 figs

  9. Neutrons and Nuclear Engineering

    International Nuclear Information System (INIS)

    Ekkebus, Allen E.

    2007-01-01

    Oak Ridge National Laboratory hosted two workshops in April 2007 relevant to nuclear engineering education. In the Neutron Stress, Texture, and Phase Transformation for Industry workshop (http://neutrons.ornl.gov/workshops/nst2/), several invited speakers gave examples of neutron stress mapping for nuclear engineering applications. These included John Root of National Research Council of Canada, Mike Fitzpatrick of the UK's Open University, and Yan Gao of GE Global Research on their experiences with industrial and academic uses of neutron diffraction. Xun-Li Wang and Camden Hubbard described the new instruments at ORNL that can be used for such studies. This was preceded by the Neutrons for Materials Science and Engineering educational symposium (http://neutrons.ornl.gov/workshops/edsym2007). It was directed to the broad materials science and engineering community based in universities, industry and laboratories who wish to learn what the neutron sources in the US can provide for enhancing the understanding of materials behavior, processing and joining. Of particular interest was the presentation of Donald Brown of Los Alamos about using 'Neutron diffraction measurements of strain and texture to study mechanical behavior of structural materials.' At both workshops, the ORNL neutron scattering instruments relevant to nuclear engineering studies were described. The Neutron Residual Stress Mapping Facility (NRSF2) is currently in operation at the High Flux Isotope Reactor; the VULCAN Engineering Materials Diffractometer will begin commissioning in 2008 at the Spallation Neutron Source. For characteristics of these instruments, as well as details of other workshops, meetings, capabilities, and research proposal submissions, please visit http://neutrons.ornl.gov. To submit user proposals for time on NRSF2 contact Hubbard at hubbardcratornl.gov

  10. Measurement of the neutron capture cross section of 99Tc using ANNRI at J-PARC

    Science.gov (United States)

    Katabuchi, Tatsuya; Mizumoto, Motoharu; Igashira, Masayuki; Terada, Kazushi; Kimura, Atsushi; Nakamura, Shoji; Nakao, Taro; Iwamoto, Osamu; Iwamoto, Nobuyuki; Mizuyama, Kazuhito; Harada, Hideo; Hori, Jun-ich; Kino, Koichi

    2017-09-01

    The neutron capture cross section of 99Tc was measured using NaI(Tl) detectors of the Accurate Neutron-Nucleus Reaction Measurement Instrument (ANNRI) at the Japan Proton Accelerator Research Complex (J-PARC) in the energy range from thermal to the keV energy region. Preliminary results were presented and compared with previous measurements and evaluations.

  11. Neutron-emission measurements at a white neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Haight, Robert C [Los Alamos National Laboratory

    2010-01-01

    Data on the spectrum of neutrons emittcd from neutron-induced reactions are important in basic nuclear physics and in applications. Our program studies neutron emission from inelastic scattering as well as fission neutron spectra. A ''white'' neutron source (continuous in energy) allows measurements over a wide range of neutron energies all in one experiment. We use the tast neutron source at the Los Alamos Neutron Science Center for incident neutron energies from 0.5 MeV to 200 MeV These experiments are based on double time-of-flight techniques to determine the energies of the incident and emitted neutrons. For the fission neutron measurements, parallel-plate ionization or avalanche detectors identify fission in actinide samples and give the required fast timing pulse. For inelastic scattering, gamma-ray detectors provide the timing and energy spectroscopy. A large neutron-detector array detects the emitted neutrons. Time-of-flight techniques are used to measure the energies of both the incident and emitted neutrons. Design considerations for the array include neutron-gamma discrimination, neutron energy resolution, angular coverage, segmentation, detector efficiency calibration and data acquisition. We have made preliminary measurements of the fission neutron spectra from {sup 235}U, {sup 238}U, {sup 237}Np and {sup 239}Pu. Neutron emission spectra from inelastic scattering on iron and nickel have also been investigated. The results obtained will be compared with evaluated data.

  12. Recoverable neutron absorbers

    International Nuclear Information System (INIS)

    Keay, R.T.; Williams, J.A.

    1982-01-01

    In the reprocessing of irradiated nuclear fuel elements the nuclear fuel material is separated from the material which forms the remainder of the elements by dissolving the nuclear fuel material in nitric acid. Neutron absorbers are added to control criticality. The neutron absorbers comprise pellets each having a core of neutron absorbing material encased in a sheath of a material which is resistant to attack by acid, the core or sheath being magnetic. The sheath protects the core of neutron absorbing material from attack by the acid and the magnetic content of the core or sheath enables the absorbers to be recovered for reuse by magnetic separation techniques. (author)

  13. Microcomputerized neutron moisture gauge

    International Nuclear Information System (INIS)

    Liu Shengkang; Mei Yu

    1987-01-01

    A microcomputerized neutron moisture gauge is introduced. This gauge consists of a neutron moisture sensor and instruments. It is developed from the neutron moisture gauge for concrete mixer. A TECH-81 single card microcomputer is used for count, computation and display. It has the function of computing compensated quantity of sand. It can acquire the data from several neutron sensors by the multichanneling sampling, therefore it can measure moisture values of sand in several hoppers simultaneously. The precision of the static state calibration curve is 0.24% wt. The error limits of the dynamic state check is < 0.50% wt

  14. Neutrons in biology

    International Nuclear Information System (INIS)

    Funahashi, Satoru; Niimura, Nobuo.

    1993-01-01

    The start of JRR-3M in 1990 was a great epoch to the neutron scattering research in Japan. Abundant neutron beam generated by the JRR-3M made it possible to widen the research field of neutron scattering in Japan. In the early days of neutron scattering, biological materials were too difficult object to be studied by neutrons not only because of their complexity but also because of the strong incoherent scattering by hydrogen. However, the remarkable development of the recent neutron scattering and its related sciences, as well as the availability of higher flux, has made the biological materials one of the most attractive subjects to be studied by neutrons. In early September 1992, an intensive workshop titled 'Neutrons in Biology' was held in Hitachi City by making use of the opportunity of the 4th International Conference on Biophysics and Synchrotron Radiation (BSR92) held in Tsukuba. The workshop was organized by volunteers who are eager to develop the researches in this field in Japan. Numbers of outstanding neutron scattering biologists from U.S., Europe and Asian countries met together and enthusiastic discussions were held all day long. The editors believe that the presentations at the workshop were so invaluable that it is absolutely adequate to put them on record as an issue of JAERI-M and to make them available for scientists to refer to in order to further promote the research in the future. (author)

  15. Neutron visual sensing technique

    International Nuclear Information System (INIS)

    Kureta, Masatoshi; Segawa, Mariko

    2014-01-01

    The neutron visual sensing technique is a technology to extract physical quantities from the information on inner structures of complex materials or machineries which have been visualized and recorded by using neutron beams. Research and utilization of this technique is now under worldwide development since it can provide the information that is not possible by X-ray radiography. We show how to use stationary neutron sources (Research reactors) in chapter 2, and how to utilize pulsed neutron source (Japan Proton Accelerator Complex, J-PARC). Also the production of micro-element analyzer by an enterprise using the knowledge on radiological equipment is described as an example. (author)

  16. Neutrons for probing matter

    International Nuclear Information System (INIS)

    Torres, F. Ed.; Mazzucchetti, D.

    2008-01-01

    The authors tell the story of the French Orphee reactor located in Saclay from the decision to build it in the seventies, to its commissioning in 1980, to its upgrading in the nineties and to its today's operating life. As early as its feasibility studies Orphee has been designed as a dual-purpose reactor: scientific research for instance in crystallography and magnetism, and industrial uses like neutron radiography, silicon doping or radionuclide production. This book is divided into 4 parts: 1) the neutron: an explorer of the matter, 2) the Orphee reactor: a neutron source, 3) the adventurers of the matter: Leon Brillouin laboratory's staff, and 4) the perspectives for neutrons

  17. Neutron scattering. Experiment manuals

    International Nuclear Information System (INIS)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

    2014-01-01

    The following topics are dealt with: The thermal triple-axis spectrometer PUMA, the high-resolution powder diffractometer SPODI, the hot-single-crystal diffractometer HEiDi, the three-axis spectrometer PANDA, the backscattering spectrometer SPHERES, the DNS neutron-polarization analysis, the neutron spin-echo spectrometer J-NSE, small-angle neutron scattering at KWS-1 and KWS-2, a very-small-angle neutron scattering diffractometer with focusing mirror, the reflectometer TREFF, the time-of-flight spectrometer TOFTOF. (HSI)

  18. Neutron scattering. Experiment manuals

    Energy Technology Data Exchange (ETDEWEB)

    Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner (eds.)

    2014-07-01

    The following topics are dealt with: The thermal triple-axis spectrometer PUMA, the high-resolution powder diffractometer SPODI, the hot-single-crystal diffractometer HEiDi, the three-axis spectrometer PANDA, the backscattering spectrometer SPHERES, the DNS neutron-polarization analysis, the neutron spin-echo spectrometer J-NSE, small-angle neutron scattering at KWS-1 and KWS-2, a very-small-angle neutron scattering diffractometer with focusing mirror, the reflectometer TREFF, the time-of-flight spectrometer TOFTOF. (HSI)

  19. Neutron powder diffraction

    International Nuclear Information System (INIS)

    David, W.I.F.

    1990-01-01

    Neutron powder diffraction is a powerful technique that provides a detailed description of moderately complex crystal structures. This is nowhere more apparent than in the area of high temperature superconductors where neutron powder diffraction has provided precise structural and magnetic information, not only under ambient conditions but also at high and low temperatures and high pressures. Outside superconductor research, the variety of materials studied by neutron powder diffraction is equally impressive including zeolites, fast ionic conductors, permanent magnets and materials undergoing phase transitions. Recent advances that include high resolution studies and real-time crystallography are presented. Future possibilities of neutron powder diffraction are discussed

  20. Neutron structural biology

    International Nuclear Information System (INIS)

    Niimura, Nobuo

    1999-01-01

    Neutron structural biology will be one of the most important fields in the life sciences which will interest human beings in the 21st century because neutrons can provide not only the position of hydrogen atoms in biological macromolecules but also the dynamic molecular motion of hydrogen atoms and water molecules. However, there are only a few examples experimentally determined at present because of the lack of neutron source intensity. Next generation neutron source scheduled in JAERI (Performance of which is 100 times better than that of JRR-3M) opens the life science of the 21st century. (author)

  1. Polycapillary neutron lenses

    International Nuclear Information System (INIS)

    Mildner, D.F.R.

    1997-01-01

    The principle of multiple mirror reflection from smooth surfaces at small grazing angles enables the transport and guiding of high intensity slow neutron beams to locations of low background for neutron scattering and absorption experiments and to provide facilities for multiple instruments. Curved guides have been widely used at cold neutron facilities to remove the unwanted radiation (fast neutrons and gamma rays) from the beam without the use of filters. A typical guide has transverse dimensions of 50 mm and, with a radius of curvature of 1 km, transmits wavelengths longer than 5 A. Much tighter curves requires narrower transverse dimensions, otherwise there is little transmission. Typical neutron benders have a number of slots with transverse dimensions of ∼5 mm. Based on the same principle but using a different technology, recent developments in glass polycapillary fibers have produced miniature versions of neutron guides. Fibers with many thousands of channels having sizes of ∼ 10 μm enable beams of long wavelength neutrons (λ > 4 A) to be transmitted efficiently in a radius of curvature as small as a fraction of 1 m. A large collection of these miniature versions of neutron guides can be used to bend the neutron trajectories such that the incident beam can be focused. (author)

  2. The neutron-gamma Feynman variance to mean approach: Gamma detection and total neutron-gamma detection (theory and practice)

    Science.gov (United States)

    Chernikova, Dina; Axell, Kåre; Avdic, Senada; Pázsit, Imre; Nordlund, Anders; Allard, Stefan

    2015-05-01

    Two versions of the neutron-gamma variance to mean (Feynman-alpha method or Feynman-Y function) formula for either gamma detection only or total neutron-gamma detection, respectively, are derived and compared in this paper. The new formulas have particular importance for detectors of either gamma photons or detectors sensitive to both neutron and gamma radiation. If applied to a plastic or liquid scintillation detector, the total neutron-gamma detection Feynman-Y expression corresponds to a situation where no discrimination is made between neutrons and gamma particles. The gamma variance to mean formulas are useful when a detector of only gamma radiation is used or when working with a combined neutron-gamma detector at high count rates. The theoretical derivation is based on the Chapman-Kolmogorov equation with the inclusion of general reactions and corresponding intensities for neutrons and gammas, but with the inclusion of prompt reactions only. A one energy group approximation is considered. The comparison of the two different theories is made by using reaction intensities obtained in MCNPX simulations with a simplified geometry for two scintillation detectors and a 252Cf-source. In addition, the variance to mean ratios, neutron, gamma and total neutron-gamma are evaluated experimentally for a weak 252Cf neutron-gamma source, a 137Cs random gamma source and a 22Na correlated gamma source. Due to the focus being on the possibility of using neutron-gamma variance to mean theories for both reactor and safeguards applications, we limited the present study to the general analytical expressions for Feynman-alpha formulas.

  3. Neutron monitoring for radiological protection

    International Nuclear Information System (INIS)

    Gibson, J.A.B.

    1985-01-01

    Neutron monitoring is a subject of increasing general interest and considerable attention is being paid to the development of improved techniques and methods for neutron monitoring. The Agency, therefore, considered it important to prepare a guide on the subject of neutron monitoring for radiation protection purposes. The present Manual is intended for those persons or authorities in Member States, particularly developing countries, who are responsible for the organization of neutron monitoring programmes and practical neutron monitoring. This Manual consequently, deals with topics such as neutron dosimetry, sources of neutrons and neutron detection as well as field instruments and operational systems used in this context

  4. Neutron Multiplicity Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Frame, Katherine Chiyoko [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-06-28

    Neutron multiplicity measurements are widely used for nondestructive assay (NDA) of special nuclear material (SNM). When combined with isotopic composition information, neutron multiplicity analysis can be used to estimate the spontaneous fission rate and leakage multiplication of SNM. When combined with isotopic information, the total mass of fissile material can also be determined. This presentation provides an overview of this technique.

  5. Neutron resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gunsing, F

    2005-06-15

    The present document has been written in order to obtain the diploma 'Habilitation a Diriger des Recherches'. Since this diploma is indispensable to supervise thesis students, I had the intention to write a document that can be useful for someone starting in the field of neutron resonance spectroscopy. Although the here described topics are already described elsewhere, and often in more detail, it seemed useful to have most of the relevant information in a single document. A general introduction places the topic of neutron-nucleus interaction in a nuclear physics context. The large variations of several orders of magnitude in neutron-induced reaction cross sections are explained in terms of nuclear level excitations. The random character of the resonances make nuclear model calculation predictions impossible. Then several fields in physics where neutron-induced reactions are important and to which I have contributed in some way or another, are mentioned in a first synthetic chapter. They concern topics like parity nonconservation in certain neutron resonances, stellar nucleosynthesis by neutron capture, and data for nuclear energy applications. The latter item is especially important for the transmutation of nuclear waste and for alternative fuel cycles. Nuclear data libraries are also briefly mentioned. A second chapter details the R-matrix theory. This formalism is the foundation of the description of the neutron-nucleus interaction and is present in all fields of neutron resonance spectroscopy. (author)

  6. Neutrons from Antiproton Irradiation

    DEFF Research Database (Denmark)

    Bassler, Niels; Holzscheiter, Michael; Petersen, Jørgen B.B.

    the volume targeted for irradiation. A major part of this peripheral dose arise from neutrons, which in particular are problematic due to their high RBE for secondary cancer incidence. We have measured the fast and thermal neutron spectrum in different geometrical configurations in order to experimentally...

  7. Neutron capture therapies

    Energy Technology Data Exchange (ETDEWEB)

    Yanch, J.C.; Shefer, R.E.; Klinkowstein, R.E.

    1999-11-02

    In one embodiment there is provided an application of the {sup 10}B(n,{alpha}){sup 7}Li nuclear reaction or other neutron capture reactions for the treatment of rheumatoid arthritis. This application, called Boron Neutron Capture Synovectomy (BNCS), requires substantially altered demands on neutron beam design than for instance treatment of deep seated tumors. Considerations for neutron beam design for the treatment of arthritic joints via BNCS are provided for, and comparisons with the design requirements for Boron Neutron Capture Therapy (BNCT) of tumors are made. In addition, exemplary moderator/reflector assemblies are provided which produce intense, high-quality neutron beams based on (p,n) accelerator-based reactions. In another embodiment there is provided the use of deuteron-based charged particle reactions to be used as sources for epithermal or thermal neutron beams for neutron capture therapies. Many d,n reactions (e.g. using deuterium, tritium or beryllium targets) are very prolific at relatively low deuteron energies.

  8. Hyperons in neutron stars

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1986-04-01

    Generalized beta equilibrium involving nucleons, hyperons, and isobars is examined for neutron star matter. The hyperons produce a considerable softening of the equation of state. It is shown that the observed masses of neutron stars can be used to settle a recent controversy concerning the nuclear compressibility. Compressibilities less than 200 MeV are incompatible with observed masses. 7 refs., 9 figs

  9. Neutron capture therapies

    Science.gov (United States)

    Yanch, Jacquelyn C.; Shefer, Ruth E.; Klinkowstein, Robert E.

    1999-01-01

    In one embodiment there is provided an application of the .sup.10 B(n,.alpha.).sup.7 Li nuclear reaction or other neutron capture reactions for the treatment of rheumatoid arthritis. This application, called Boron Neutron Capture Synovectomy (BNCS), requires substantially altered demands on neutron beam design than for instance treatment of deep seated tumors. Considerations for neutron beam design for the treatment of arthritic joints via BNCS are provided for, and comparisons with the design requirements for Boron Neutron Capture Therapy (BNCT) of tumors are made. In addition, exemplary moderator/reflector assemblies are provided which produce intense, high-quality neutron beams based on (p,n) accelerator-based reactions. In another embodiment there is provided the use of deuteron-based charged particle reactions to be used as sources for epithermal or thermal neutron beams for neutron capture therapies. Many d,n reactions (e.g. using deuterium, tritium or beryllium targets) are very prolific at relatively low deuteron energies.

  10. Compact neutron generator

    Science.gov (United States)

    Leung, Ka-Ngo; Lou, Tak Pui

    2005-03-22

    A compact neutron generator has at its outer circumference a toroidal shaped plasma chamber in which a tritium (or other) plasma is generated. A RF antenna is wrapped around the plasma chamber. A plurality of tritium ion beamlets are extracted through spaced extraction apertures of a plasma electrode on the inner surface of the toroidal plasma chamber and directed inwardly toward the center of neutron generator. The beamlets pass through spaced acceleration and focusing electrodes to a neutron generating target at the center of neutron generator. The target is typically made of titanium tubing. Water is flowed through the tubing for cooling. The beam can be pulsed rapidly to achieve ultrashort neutron bursts. The target may be moved rapidly up and down so that the average power deposited on the surface of the target may be kept at a reasonable level. The neutron generator can produce fast neutrons from a T-T reaction which can be used for luggage and cargo interrogation applications. A luggage or cargo inspection system has a pulsed T-T neutron generator or source at the center, surrounded by associated gamma detectors and other components for identifying explosives or other contraband.

  11. Synovectomy by Neutron capture

    International Nuclear Information System (INIS)

    Vega C, H.R.; Torres M, C.

    1998-01-01

    The Synovectomy by Neutron capture has as purpose the treatment of the rheumatoid arthritis, illness which at present does not have a definitive curing. This therapy requires a neutron source for irradiating the articulation affected. The energy spectra and the intensity of these neutrons are fundamental since these neutrons induce nuclear reactions of capture with Boron-10 inside the articulation and the freely energy of these reactions is transferred at the productive tissue of synovial liquid, annihilating it. In this work it is presented the neutron spectra results obtained with moderator packings of spherical geometry which contains in its center a Pu 239 Be source. The calculations were realized through Monte Carlo method. The moderators assayed were light water, heavy water base and the both combination of them. The spectra obtained, the average energy, the neutron total number by neutron emitted by source, the thermal neutron percentage and the dose equivalent allow us to suggest that the moderator packing more adequate is what has a light water thickness 0.5 cm (radius 2 cm) and 24.5 cm heavy water (radius 26.5 cm). (Author)

  12. Neutron supermirrors and application to neutron guides

    International Nuclear Information System (INIS)

    Ballot, B.; Samuel, F.; Farnoux, B.

    1994-01-01

    Metallic multilayers are now commonly used in many neutron optics devices like supermirrors. Supermirrors are made of stacks of aperiodic bilayers, and present a reflection coefficient close to one for angles much larger than the critical angle of nickel. We show here the results of investigation of neutron reflectometry of such supermirrors. They have been prepared by magnetron sputtering and are made of 25 layers of NiC and Ti, thicknesses of which were determined using the Hayter's algorithm [1]. This enables us to obtain on large surfaces 5x50 cm 2 , an effective critical angle of 1.9 times the critical angle of natural nickel. These supermirrors have been used in the construction of a new neutron guide on the ORPHEE reactor in the Leon Brillouin Laboratory of Saclay. The use of supermirrors enables us to enhance the transmission of the short wavelength by the guide, and so to increase the transmitted flux. ((orig.))

  13. The parallel processing impact in the optimization of the reactors neutronic by genetic algorithms; O impacto do processamento paralelo na otimizacao de projeto neutronico de reator atraves de algoritmo genetico

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Claudio M.N.A. [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil). Div. de Reatores]|[Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear; E-mail: cmnap@ien.gov.br; Lapa, Celso M.F.; Mol, Antonio C.A. [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil). Div. de Reatores]. E-mail: lapa@ien.gov.br; mol@ien.gov.br

    2002-07-01

    Nowadays, many optimization problems found in nuclear engineering has been solved through genetic algorithms (GA). The robustness of such methods is strongly related to the nature of search process which is based on populations of solution candidates, and this fact implies high computational cost in the optimization process. The use of GA become more critical when the evaluation process of a solution candidate is highly time consuming. Problems of this nature are common in the nuclear engineering, and an example is the reactor design optimization, where neutronic codes, which consume high CPU time, must be run. Aiming to investigate the impact of the use of parallel computation in the solution, through GA, of a reactor design optimization problem, a parallel genetic algorithm (PGA), using the Island Model, was developed. Exhaustive experiments, then 1500 processing hours in 550 MHz personal computers, have been done, in order to compare the conventional GA with the PGA. Such experiments have demonstrating the superiority of the PGA not only in terms of execution time, but also, in the optimization results. (author)

  14. Fast neutrons dosimetry

    International Nuclear Information System (INIS)

    Rzyski, B.M.

    1977-01-01

    A proton recoil technique has been developed for inducing thermoluminescence with incident fast neutrons. CaF 2 was used as the TL phosphor, and cane sugar and polyethylene were used as proton radiators. The phosphor and the hydrogeneous material powders were well mixed, encapsulated in glass tubes and exposed to Am-Be sources, resulting in recoils from incident fast neutrons of energy between 0,25 and 11,25 MeV. The intrinsic response of pure CaF 2 to fast neutrons without a hydrogeneous radiator was checked by using LiF (TLD-700). Glow curves were recorded from room temperature up to 350 0 C after different doses of neutrons and gamma rays of 60 Co. First collision dose due to fast neutrons in tissue like materials such as cane sugar and polyethylene was also calculated [pt

  15. Neutron Stars and Pulsars

    CERN Document Server

    Becker, Werner

    2009-01-01

    Neutron stars are the most compact astronomical objects in the universe which are accessible by direct observation. Studying neutron stars means studying physics in regimes unattainable in any terrestrial laboratory. Understanding their observed complex phenomena requires a wide range of scientific disciplines, including the nuclear and condensed matter physics of very dense matter in neutron star interiors, plasma physics and quantum electrodynamics of magnetospheres, and the relativistic magneto-hydrodynamics of electron-positron pulsar winds interacting with some ambient medium. Not to mention the test bed neutron stars provide for general relativity theories, and their importance as potential sources of gravitational waves. It is this variety of disciplines which, among others, makes neutron star research so fascinating, not only for those who have been working in the field for many years but also for students and young scientists. The aim of this book is to serve as a reference work which not only review...

  16. Neutrons for matter exploration: neutron spectroscopy in condensed matter physics

    International Nuclear Information System (INIS)

    Kahn, R.

    1997-01-01

    The physical properties and the various uses of neutrons for characterizing structures (through neutron diffraction) and condensed matter dynamics (through Doppler effect), are reviewed. Results and potential observations are given for the different methods: neutron diffraction, small angle scattering, reflectometry, neutron inelastic scattering. The two CEA laboratories where these studies may be carried out are presented

  17. Neutrons and the crystal ball experiments

    International Nuclear Information System (INIS)

    Alyea, J.; Grosnick, D.; Koetke, D.; Manweiler, R.; Spinka, H.; Stanislaus, S.

    1997-01-01

    The Crystal Ball detector, as originally constructed, consisted of a set of 672 optically-isolated NaI crystals, forming an approximately spherical shell and each crystal viewed by a photomultiplier, a charged-particle tracker within the NaI shell, and two endcaps to cover angles close to two colliding beams. The detector geometry subtends a solid angle of about 93% of 4π st (20 degree le θ le 160degree and 0degree le φ le 360degree) from the center. The Crystal Ball detector was used for two long series of experiments at the e + e - colliding beam accelerators SPEAR [1, 2, 3, 4] at SLAC and DORIS [5, 6, 7, 8] at DESY. A new set of measurements using the Crystal Ball detector is planned at the Brookhaven National Laboratory Alternating Gradient Synchrotrons (BNL AGS). These new experiments will use the 672 NaI crystals from the original detector, but neither the tracker nor endcaps. The ''Crystal Ball'' in this note will refer only to the set of NaI crystals. Initially, the reactions to be studied will include π - pr a rrow neutrals with pion beam momenta approximately400-750 MeV/c and K - pr a rrow neutrals with kaon beam momenta approximately600-750 MeV/c. Each of these reactions will include a neutron in the final state. whereas the fraction of e + e - interactions with neutrons at SLAC or DESY was quite small. Consequently, there is relatively little experience understanding the behavior of neutrons in the Crystal Ball

  18. Fail-safe neutron shutter used for thermal neutron radiography

    International Nuclear Information System (INIS)

    Sachs, R.D.; Morris, R.A.

    1976-11-01

    A fail-safe, reliable, easy-to-use neutron shutter was designed, built, and put into operation at the Omega West Reactor, Los Alamos Scientific Laboratory. The neutron shutter will be used primarily to perform thermal neutron radiography, but is also available for a highly collimated source of thermal neutrons [neutron flux = 3.876 x 10 6 (neutrons)/(cm 2 .s)]. Neutron collimator sizes of either 10.16 by 10.16 cm or 10.16 by 30.48 cm are available

  19. High Pressure Apparatus for Angle Dispersive Neutron Diffraction

    OpenAIRE

    Kazuo, Kamigaki; Takejiro, Kaneko; Shunya, Abe; Masayoshi, Ohashi

    1983-01-01

    A piston-cylinder type high pressure apparatus was designed for the angle dispersive neutron diffraction. A Ti-53wt% Zr alloy was used for the cylinder. The performance was tested by observing the structural transformation under pressure in RbBr from an NaCl-type to a CsCl-type.

  20. Epiboron Neutron Activation Analysis with Nigeria Research Reactor

    African Journals Online (AJOL)

    Epiboron neutron activation analysis is optimized using Nigeria Research Reactor-1. Data are given for 6 elements using boron as shielding. Boron shield are of particular practical value for rapid instrumental analysis. Advantage factors for the following elements: I, Br, Cl, K, Mn and Na under boron shield are given.

  1. Investigation of mixture heterogeneity by neutron activation analysis

    International Nuclear Information System (INIS)

    Smakhtin, L.A.; Kurinov, A.D.; Shokel', E.S.; Merkulov, A.V.

    1981-01-01

    Instrumental methods of activation analysis have been developed to study the distribution of heterogeneity of Co, Na, Cu, Tb additives in ferrite charge and Sn in silicon oxide. Reasons have been examined for arising systematic errors during neutron-activation estimation of a heterogeneity coefficient. Ways are proposed to eliminate them [ru

  2. Electron-volt spectroscopy at a pulsed neutron source using a resonance detector technique

    CERN Document Server

    Andreani, C; Senesi, R; Gorini, G; Tardocchi, M; Bracco, A; Rhodes, N; Schooneveld, E M

    2002-01-01

    The effectiveness of the neutron resonance detector spectrometer for deep inelastic neutron scattering measurements has been assessed by measuring the Pb scattering on the eVS spectrometer at ISIS pulsed neutron source and natural U foils as (n,gamma) resonance converters. A conventional NaI scintillator with massive shielding has been used as gamma detector. A neutron energy window up to 90 eV, including four distinct resonance peaks, has been assessed. A net decrease of the intrinsic width of the 6.6 eV resonance peak has also been demonstrated employing the double difference spectrum technique, with two uranium foils of different thickness.

  3. Elemental analysis of fertilizer by fast neutron activation

    International Nuclear Information System (INIS)

    Bodart, F.; Deconninck, G.

    1977-01-01

    A simple and accurate technique has been developed to analyse commercial fertilizers for phosphorus, potassium, chlorine, magnesium and silicon. The method is based on fast-neutron activation using a neutron flux of 2x10 11 neutrons/second. The optimum analytical conditions are tabulated. After irradiation, the sample is measured on a conventional counting system including a Ge(Li) detector (10% efficiency and 2 keV resolution for 60 Co) and a multichannel analyser. Monitor foils radioactivity are measured separately at the same time with a 2''x2''NaI detector coupled with a single channel analyser and a scaler. Fast neutron activation has proved to be a fast, simple, reliable and low cost analytical technique for the determination of phosphorus, silicon, potassium, magnesium and chlorine in fertilizers. Not less than five phosphorus determinations are possible in one hour, while two potassium, magnesium and chlorine determinations are made at the same time. (T.G.)

  4. Basic Physics Data: Measurement of Neutron Multiplicity from Induced Fission

    Energy Technology Data Exchange (ETDEWEB)

    Pozzi, Sara [Univ. of Michigan, Ann Arbor, MI (United States); Haight, Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-05-04

    From October 1 to October 17 a team of researchers from UM visited the LANSCE facility for an experiment during beam-time allotted from October 4 to October 17. A total of 24 detectors were used at LANSCE including liquid organic scintillation detectors (EJ-309), NaI scintillation detectors, and Li-6 enriched glass detectors. It is a double time-offlight (TOF) measurement using spallation neutrons generated by a target bombarded with pulsed high-energy protons. The neutrons travel to an LLNL-manufactured parallel plate avalanche chamber (PPAC) loaded with thin U-235 foils in which fission events are induced. The generated fission neutrons and photons are then detected in a detector array designed and built at UM and shipped to LANSCE. Preparations were made at UM, where setup and proposed detectors were tested. The UM equipment was then shipped to LANSCE for use at the 15L beam of the weapons neutron research (WNR) facility.

  5. Texture investigations of natural rock salt using neutron diffraction

    International Nuclear Information System (INIS)

    Ertel, A.

    1987-01-01

    The main benefits and constraints are described of X-ray and neutron diffraction. Tabulated are diffraction factors and absorption coefficients of Na, Cl, K, S, O, Ca and Mg for both methods and a comparison is made of neutron and X-ray penetration depths at 50% absorption for halite, sylvine, polyhalite, kieserite, anhydrite and hematite. Neutron diffraction was used for the study of preferred orientation in halite from mines in Zielitz (GDR), Bleicherode (GDR) and Werra (GDR). The experiments were carried out at the research reactor at ZfK Rossendorf, GDR. Samples were irradiated with a flux density of monochromatic thermal neutrons of 10 8 n.cm -2 s -1 . Measured were (200), (220) and (222) pole figures of halite. In the samples from Zielitz and Bleicherode a (100) fibre texture was found, in samples from Werra a (110) fibre texture. (E.S.) 23 refs., 11 figs., 2 tabs

  6. Spectroscopic Investigations with Dual Neutron-Gamma Scintillators

    Science.gov (United States)

    Chowdhury, P.; Brown, T.; Doucet, E.; Lister, C. J.; Morse, C.; Rogers, A. M.; Wilson, G. L.; Devlin, M.; Fotiades, N.; Gomez, J. A.; Mosby, S.

    2017-09-01

    The spectroscopic capabilities of 7Li-enriched Cs27LiYCl6 (C7LYC) dual neutron-gamma scintillators are being tested in diverse application arenas to exploit the excellent pulse-shape discrimination together with the unprecedented pulse height resolution ( 10%) for fast neutrons in the performed. A key goal is to evaluate whether the low intrinsic efficiency of C7LYC for fast neutrons compared to traditional neutron detectors, such as liquid scintillators, can be effectively offset by the gain in solid angle obtained by positioning the detectors much closer to the target, since the typical long time-of-flight arms for energy resolution are not necessary. Supported by the NNSA Stewardship Science Academic Alliance Program under Grant DE-NA0002932.

  7. Fast Neutron Spectroscopy using a CLYC array

    Science.gov (United States)

    Doucet, Emery; Brown, T.; Chowdhury, P.; Lister, C. J.; Wilson, G. L.; Devlin, M.; Mosby, S.

    2015-10-01

    A new inorganic scintillator, Cs2LiYCl6, or CLYC, has recently shown great promise as a dual gamma-neutron detector, where neutron-gamma discrimination is achieved through digital pulse shape processing. The 35Cl(n,p) reaction allows fast neutrons to be measured with an energy resolution of ~10 %. Following initial tests with natural Li, 6Li-depleted crystals were chosen to reduce the strong thermal capture response of 6Li. A 16-element array of 1'' x 1'' 6Li-depleted CLYC crystals is being tested in a variety of applications. A VME-based digital DAQ is used for pulse shape discrimination and extracting energies. The array was deployed at the LANSCE WNR facility, to measure elastic and inelastic scattering cross sections of neutrons on 56Fe and 238U. The data acquisition and analysis software were originally based on Python. The sorting codes were re-written in C, which sped up the analysis by two orders of magnitude. Most of the sorting code is within the framework of the CERN-ROOT software. Details of the detector array and the analysis will be presented. Supported by NNSA-SSAA program through DOE Grant DE-NA00013008.

  8. Thermal neutron absorption borehole logging

    International Nuclear Information System (INIS)

    Flaum, C.

    1982-01-01

    A method is described of quantitatively determining the macroscopic thermal neutron cross-section of a geological formation traversed by a borehole by measuring the flux of both thermal and epithermal neutrons following the irradiation of the formation with neutrons from a continuous source in a neutron sonde. (U.K.)

  9. Quantitative analysis of silicates by instrumental epithermal neutron activation using (n,p) reactions

    International Nuclear Information System (INIS)

    Gladney, E.S.; Perrin, D.R.

    1979-01-01

    Instrumental epithermal neutron activation (IENA) involves the use of a neutron filter to screen out the thermal portion of the reactor neutron energy spectrum. Both Cd and B are efficient neutron filters. The principal advantage of epithermal over conventional thermal neutron activation for elemental analysis of geological materials is that the most common rock forming elements, which activate strongly with thermal neutrons (Na, Al, P, K, Fe, and Sc), have their activities suppressed, relative to elements which have cross-sectional resonances in the epithermal energy region. One-gram samples of various silicate standard reference materials were encapsulated in polyethylene vials and irradiated in the Los Alamos Omega West Reactor epithermal facility. Only six elements (F, Si, Na, Fe, Ni, and Ti) were successfully determined in geological matrices via (n,p) reactions. The single standard deviations among the measurements were less than 10% in all cases. The production ratio of (n,p) to (n,γ) and (n,p) to (n,α) interfering reactions are included for silicate materials having Mason's average crustal abundance of elements. Epithermal activation via (n,p) reactions provides an alternative method for the determination of Fe, Al, Na, Ni, and F. The preferred techniques are probably thermal neutron activation for the first three elements, atomic absorption for Ni, and ion selective electrode for F.Titanium and Si can be measured much more sensitively using the (n,p) reaction than by thermal neutron activation. 4 tables

  10. Neutron flux monitor

    International Nuclear Information System (INIS)

    Oda, Naotaka.

    1993-01-01

    The device of the present invention greatly saves an analog processing section such as an analog filter and an analog processing circuit. That is, the device of the present invention comprises (1) a neutron flux detection means for detecting neutron fluxed in the reactor, (2) a digital filter means for dividing signals corresponding to the detected neutron fluxes into predetermined frequency band regions, (3) a calculation processing means for applying a calculation processing corresponding to the frequency band regions to the neutron flux detection signals divided by the digital filter means. With such a constitution, since the neutron detection signals are processed by the digital filter means, the accuracy is improved and the change for the property of the filter is facilitated. Further, when a neutron flux level is obtained, a calculation processing corresponding to the frequency band region can be conducted without the analog processing circuit. Accordingly, maintenance and accuracy are improved by greatly decreasing the number of parts. Further, since problems inherent to the analog circuit are solved, neutron fluxes are monitored at high reliability. (I.S.)

  11. Neutron detection technique

    CERN Document Server

    Oblath, N S

    2000-01-01

    The Sudbury Neutrino Observatory (SNO) has the ability to measure the total flux of all active flavors of neutrinos using the neutral current reaction, whose signature is a neutron. By comparing the rates of the neutral current reaction to the charged current reaction, which only detects electron neutrinos, one can test the neutrino oscillation hypothesis independent of solar models. It is necessary to understand the neutron detection efficiency of the detector to make use of the neutral current reaction. This report demonstrates a coincidence technique to identify neutrons emitted from the sup 2 sup 5 sup 2 Cf neutron calibration source. The source releases on average four neutrons when a sup 2 sup 5 sup 2 Cf nucleus spontaneously fissions. Each neutron is detected as a separate event when the neutron is captured by a deuteron, releasing a gamma ray of approximately 6.25 MeV. This gamma ray is in turn detected by the photomultiplier tube (PMT) array. By investigating the time and spatial separation between n...

  12. Neutron Laue macromolecular crystallography.

    Science.gov (United States)

    Meilleur, Flora; Myles, Dean A A; Blakeley, Matthew P

    2006-09-01

    Recent progress in neutron protein crystallography such as the use of the Laue technique and improved neutron optics and detector technologies have dramatically improved the speed and precision with which neutron protein structures can now be determined. These studies are providing unique and complementary insights on hydrogen and hydration in protein crystal structures that are not available from X-ray structures alone. Parallel improvements in modern molecular biology now allow fully (per)deuterated protein samples to be produced for neutron scattering that essentially eradicate the large-and ultimately limiting-hydrogen incoherent scattering background that has hampered such studies in the past. High quality neutron data can now be collected to near atomic resolution (approximately 2.0 A) for proteins of up to approximately 50 kDa molecular weight using crystals of volume approximately 0.1 mm3 on the Laue diffractometer at ILL. The ability to flash-cool and collect high resolution neutron data from protein crystals at cryogenic temperature (15 K) has opened the way for kinetic crystallography on freeze trapped systems. Current instrument developments now promise to reduce crystal volume requirements by a further order of magnitude, making neutron protein crystallography a more accessible and routine technique.

  13. Convergent beam neutron crystallography

    Science.gov (United States)

    Gibson, Walter M.; Schultz, Arthur J.; Richardson, James W.; Carpenter, John M.; Mildner, David F. R.; Chen-Mayer, Heather H.; Miller, M. E.; Maxey, E.; Prask, Henry J.; Gnaeupel-Herold, Thomas H.; Youngman, Russell

    2004-01-01

    Applications of neutron diffraction for small samples (small fiducial areas are limited by the available neutron flux density. Recent demonstrations of convergent beam electron and x-ray diffraction and focusing of cold (λ>1 Å) neutrons suggest the possibility to use convergent beam neutron diffraction for small sample crystallography. We have carried out a systematic study of diffraction of both monoenergetic and broad bandwidth neutrons at the NIST Research Reactor and at the Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory. Combining convergent beams with time-of-flight Laue diffraction is particularly attractive for high efficiency small sample diffraction studies. We have studied single crystal and powder diffraction of neutrons with convergence angles as large as 15° and have observed diffracted peak intensity gains greater than 20. The convergent beam method (CBM) shows promise for crystallography on small samples of small to medium size molecules (potentially even for proteins), ultra-high pressure samples, and for mapping of strain and texture distributions in larger samples.

  14. Materials for neutron beam optimization for boron neutron capture therapy

    International Nuclear Information System (INIS)

    Matsumoto, Tetsuo

    2001-01-01

    Several prospective materials (neutron filter/moderator, beam reflector, gamma ray shielding and beam collimator) were studied with a view to generating thermal and epithermal neutron beams suited for boron neutron capture therapy (BNCT). The beams are delivered from the thermal and thermalizing column exits situated on two opposite faces of a TRIGA-II type reactor. An investigation was performed with Monte Carlo calculations from a viewpoint of obtaining sufficiently intense thermal and epithermal neutron beams separately, and little adulterated both with neutrons of extraneous energy ranges and with gamma rays. High-density graphite (G) would be the most suitable material for thermal neutron beams as a neutron filter/moderator, and the combination of aluminum (Al) and aluminum fluoride (AlF 3 ) for epithermal neutron beams. The graphite would be also the most promising material for thermal neutron beams as a beam reflector while for epithermal neutron beams the choice would be lead fluoride (PbF 2 ). The PbF 2 would be also the most suitable material for epithermal neutron beams as a gamma ray shielding, and bismuth (Bi) for thermal neutron beam. The PbF 2 would be also the most useful material for epithermal neutron beam as a beam collimator while for thermal neutron beam the choice would be the graphite. The epithermal neutron beam for BNCT could be optimized with the progressive use of PbF 2 . (author)

  15. Virtual neutron scattering experiments

    DEFF Research Database (Denmark)

    Overgaard, Julie Hougaard; Bruun, Jesper; May, Michael

    2016-01-01

    We describe how virtual experiments can be utilized in a learning design that prepares students for hands-on experiments at large-scale facilities. We illustrate the design by showing how virtual experiments are used at the Niels Bohr Institute in a master level course on neutron scattering....... In the last week of the course, students travel to a large-scale neutron scattering facility to perform real neutron scattering experiments. Through student interviews and survey answers, we argue, that the virtual training prepares the students to engage more fruitfully with experiments by letting them focus...

  16. Virtual neutron scattering experiments

    DEFF Research Database (Denmark)

    Overgaard, Julie Hougaard; Bruun, Jesper; May, Michael

    2017-01-01

    We describe how virtual experiments can be utilized in a learning design that prepares students for hands-on experiments at large-scale facilities. We illustrate the design by showing how virtual experiments are used at the Niels Bohr Institute in a master level course on neutron scattering....... In the last week of the course, students travel to a large-scale neutron scattering facility to perform real neutron scattering experiments. Through student interviews and survey answers, we argue, that the virtual training prepares the students to engage more fruitfully with experiments by letting them focus...

  17. Neutron irradiation therapy machine

    International Nuclear Information System (INIS)

    1980-01-01

    Conventional neutron irradiation therapy machines, based on the use of cyclotrons for producing neutron beams, use a superconducting magnet for the cyclotron's magnetic field. This necessitates complex liquid He equipment and presents problems in general hospital use. If conventional magnets are used, the weight of the magnet poles considerably complicates the design of the rotating gantry. Such a therapy machine, gantry and target facilities are described in detail. The use of protons and deuterons to produce the neutron beams is compared and contrasted. (U.K.)

  18. Coupled moderator neutronics

    International Nuclear Information System (INIS)

    Russell, G.J.; Pitcher, E.J.; Ferguson, P.D.

    1995-01-01

    Optimizing the neutronic performance of a coupled-moderator system for a Long-Pulse Spallation Source is a new and challenging area for the spallation target-system designer. For optimal performance of a neutron source, it is essential to have good communication with instrument scientists to obtain proper design criteria and continued interaction with mechanical, thermal-hydraulic, and materials engineers to attain a practical design. A good comprehension of the basics of coupled-moderator neutronics will aid in the proper design of a target system for a Long-Pulse Spallation Source

  19. Fruits of neutron research

    International Nuclear Information System (INIS)

    Krause, C.

    1994-01-01

    Car windshields that don't break during accidents and jets that fly longer without making a refueling stop. Compact discs, credit cards, and pocket calculators. Refrigerator magnets and automatic car window openers. Beach shoes, food packaging, and bulletproof vests made of tough plastics. The quality and range of consumer products have improved steadily since the 1970s. One of the reasons: neutron research. Industries, employing neutron scattering techniques, to study materials properties, to act as diagnostics in tracing system performance, or as sources for radioactive isotopes used in medical fields for diagnostics or treatment, have all benefited from the fruits of advanced work with neutron sources

  20. Neutron scattering in liquids

    Energy Technology Data Exchange (ETDEWEB)

    Barocchi, F. [Florence Univ. (Italy). Ist. di Fisica

    1996-12-31

    Together with X-rays, thermal neutrons are the ideal probe to study the microscopic structure of condensed matter, however the precision attainable usually with neutrons for the measurement of atomic position correlation functions in liquids is, at least, one order of magnitude better than for X-rays. In order to measure properly the microscopic dynamics a wide range of momentum transfer with corresponding energy transfer must be available in the range of liquid state excitations. This again is only attainable, with good resolution, with neutrons. (author) 7 figs., 3 refs.

  1. Neutrons in soft matter

    CERN Document Server

    Imae, Toyoko; Furusaka, Michihiro; Torikai, Naoya

    2011-01-01

    Neutron and synchrotron facilities, which are beyond the scale of the laboratory, and supported on a national level in countries throughout the world.  These tools for probing micro- and nano-structure research and on fast dynamics research of atomic location in materials have been key in the development of new polymer-based materials. Different from several existing professional books on neutron science, this book focuses on theory, instrumentation, an applications. The book is divided into five parts: Part 1 describes the underlying theory of neutron scattering. Part 2 desc

  2. Technological characterization of new clay deposits in the south region of Amapa, Brazil aiming applications in the ceramic industry; Caracterizacao tecnologica de novos depositos de argilas da regiao sul do Amapa visando aplicacoes na industriav ceramica

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Adriano Lima da; Luna, Carlos Bruno Barreto; Chaves, Alexsandra Cristina; Neves, Gelmires de Araujo, E-mail: adrianolimadasilva@hotmail.com, E-mail: brunobarretodemaufcg@hotmail.com [Universidade Federal de Campina Grande (UAEMa/CCT/UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

    2017-01-15

    The objective of the present work was to characterize two new Clay deposits (A and B) from the south region of Amapa state, aiming to establish their adequate uses as ceramic raw materials and to promote the potential of the ceramic industry in the region. Were prepared specimens by uniaxial pressing, being applied a two phase pressing of 13,4 MPa and 20 MPa, respectively. The samples were dried in an oven at 110 deg C, and submitted to burning at 850, 1000 and 1200 deg C. Were determined linear firing shrinkage, water absorption, apparent porosity and modulus of flexural modulus of rupture, as well as mineralogical evolution after burning. Finishing, the microstructure of the sintered clay at 1200 deg C was evaluated in a scanning electron microscope. The results showed that the clay A presented a better mechanical development, having a red coloration and, therefore, potential to the red ceramic industry. On the other hand, the clay B presented a light color, due to a low content of iron oxide and, therefore, having potential as refractory raw material. In general, one clay is suitable to be used in white ceramic and the other in red ceramic. (author)

  3. Influence of temperature on power output of a panel of polycrystalline silicon in the west region of Parana, Brazil; Influencia da temperatura sobre a potencia de saida de um painel de silicio policristalino na regiao oeste paranaense

    Energy Technology Data Exchange (ETDEWEB)

    Michels, Roger Nabeyama; Santos, Jose Airton Azevedo dos; Gnoatto, Estor; Kawanagh, Edward; Fischborn, Marcos [Universidade Tecnologica Federal do Parana (UTFPR), Medianeira, PR (Brazil); Halmeman, Maria Cristina Rodrigues [Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil)

    2008-07-01

    Photovoltaic panels have been confirmed as an alternative source of electric energy. However, the output power of a photovoltaic panel is strongly dependent on solar intensity modifications and ambient temperature too. Then, it is necessary to know like the panels work under these alterations. This work intend to analyze the influence of the temperature on the output power of a polycrystalline silicon photovoltaic panel in Medianeira City located in West Region of Parana State by one year observation period. (author)

  4. Comparison of the microstructure and composition of aboriginal ceramics, from indigenous site Caninhas, with the obtained ones in the region; Comparacao da microestrutura e da composicao de ceramicas indigenas provenientes do sitio arqueologico Caninhas, com as obtidas atualmente na regiao

    Energy Technology Data Exchange (ETDEWEB)

    Matos, C.C.; Nakano, F.P.; Taguchi, S.P.; Camargo-Vernilli, D., E-mail: cristhian@alunos.eel.usp.b [Universidade de Sao Paulo (DEMAR/EEL/USP), Lorena, SP (Brazil). Escola de Engenharia de Lorena. Dept. de Engenharia de Materiais; Ribeiro, R.B.; Rosa, S.J. L. [Faculdades Integradas Teresa D' Avila (FATEA), Lorena, SP (Brazil). Rede Salesianas. Dept. de Desenho Industrial

    2009-07-01

    The archaeological site of Caninhas is made of funeral and combustion structures and various objects of aboriginal daily use. These parts and fragments were safe and inventoried, constituting approximately 4000 units. The objective of this project was to analyze the microstructure and composition of archaeological ceramics, and ceramics made of argil current of the zone. The crystalline phases were identified by X-Rays Diffraction (XRD), elementary composition was obtained by X-Rays Fluorescence (XRF) and Energy Dispersive Spectrometry (EDS), and the microstructure was evaluated by Scanning Electron Microscope (SEM). Composition and microstructure of archaeological ceramics are different of current ceramics, indicating the effect of lixiviation in function of the time and the microstructural evolution due different ceramic processing. These results are valuable for the archaeological area studies, mainly for the cultural denoting which represents. The relation between some studies is basic to add knowledge: use of the ceramic materials engineering for archaeology application. (author)

  5. Urban index modelling for forecasting of channeled natural gas market: an example in Sao Paulo metropolitan region; Modelagem de indicadores urbanos para previsao do mercado de gas natural canalizado: um exemplo na regiao metropolitana de Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Massara, Vanessa Meloni; Faga, Murilo Tadeu Werneck; Udaeta, Miguel Edgar Morales [Universidade Sao Paulo (USP), SP (Brazil). Programa Interunidades de Pos Graduacao em Energia]. E-mail: vmassara@iee.usp.br; murfaga@iee.usp.br; udaeta@pea.usp.br

    2006-07-01

    This paper aims to present a systemic model for analysis of the expansion and grow up of the natural gas distribution pipeline in a city. This methodology integrates the understanding of the urban dynamics to the strategies of expansion in the natural gas distribution network, through the grouping of information such as family income, demographic density and construction area, percentage of land use, number of households as well as commercial, service and industrial establishments, number of real state as well as indicative information released by the Urban Plan of the city regarding the increments in the peripheral districts. Relating the gas consumption esteemed by each type of land occupation and the cost for expanding the gas distribution network, the model will indicate, for each neighborhood, the viability of implementing a gas network as well as the places with potential for growing density in the existing gas distribution system. The aim is to propose an integration of aspects of city dynamics and new energy source development, taking the advance of natural gas in Sao Paulo Metropolitan area as a specific case study. Through the analysis of highly industrialized, residential and commercial suburbs of the City of Sao Caetano do Sul, the importance of urban parameters in the decision making process for network expansion is identified. (author)

  6. Monitoring of meteorology and air quality at influence area of COMPERJ (Rio de Janeiro Petrochemical Complex); Monitoramento meteorologico e da qualidade do ar na regiao de influencia do COMPERJ (Complexo Petroquimico do Rio de Janeiro)

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Edler Lins de; Villa, Felipe de Santana; Lyra, Diogenes Ganghis Pimentel de [CETREL-LUMINA Solucoes Ambientais, Salvador, BA (Brazil); Secron, Marcelo; Iorio, Patricia Freire; Mendes, Marcos Faistauer [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    Rio de Janeiro Petrochemical Complex (COMPERJ) will be installed in the north region of Itaborai city. The start of COMPERJ operations is foreseen to 2012. Because of the intensification of industrialization and urbanization processes, the implantation of COMPERJ will bring environmental modifications for Itaborai city and neighbors areas. Thus, meteorological and air quality monitoring was initiated in February of 2007 with the intention of carrying out a characterization of air pollution in this area, before COMPERJ operations. In this work are presented the results found in campaigns performed of February of 2007 until April of 2008. The meteorological monitoring disclosed that the meteorological parameters have varied enough throughout the months, but these are representative of a global behavior of the studied area. Monitoring of air quality has shown that atmospheric levels of monitored pollutants has been generally below of Brazilian air quality standards. This fact corroborates the basic aspect of the present study: identification of the concentrations 'background' in the studied area. Throughout the period of monitoring, the primary air quality standard for ozone has been reached. Observations of meteorological parameters indicate that this fact is associated to the emissions originated from Sao Goncalo, Niteroi and Rio de Janeiro cities. (author)

  7. Study of a region's clay of Campos dos Goytacazes-RJ for application in red ceramic industry; Estudo de uma argila da regiao de Campos dos Goytacazes-RJ para aplicacao na industria de ceramica vermelha

    Energy Technology Data Exchange (ETDEWEB)

    Scarpini, V.; Mangueira, G.M.; Vieira, C.M.F.; Alexandre, J., E-mail: v.scarpini@yahoo.com.br [Universidade Estadual do Norte Fluminense Darcy Ribeiro (LAMAV/UENF), Campos dos Goytacazes, RJ (Brazil). Laboratorio de Materiais Avancados

    2011-07-01

    This work aims to study a region's clay of Campos dos Goytacazes - RJ for possible application in the red ceramic industry. The clay was subjected to tests of X-ray diffraction, X-ray fluorescence, sieving and sedimentation by gravity and plasticity tests. Subsequently body test were prepared by pressing for burning in muffle furnace at temperatures of 750 ° C, 850 ° C and 950 deg C. The ceramic samples were tested for water absorption and breakdown voltage of three point bending. The results indicated that the clay contains predominantly kaolinite, muscovite mica, gibbsite and quartz, and it is presented as a plastic material and should be used in combination with a non-plastic material. (author)

  8. Compressed natural gas as a vehicle to promote development of consumer market in Campina Grande - PB (Brazil); O gas natural comprimido como fomentador do desenvolvimento do mercado consumidor de gas natural na regiao de Campina Grande - PB

    Energy Technology Data Exchange (ETDEWEB)

    Bonfim, Marcelo dos Santos; Santos, Edmilson Moutinho dos [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Eletrotecnica e Energia. Programa Interunidades de Pos-Graduacao em Energia (PIPGE)

    2004-07-01

    Investments required for natural gas distribution networks are high. The use of compressed natural gas (CNG) is seen as a way to prepare and develop consuming markets to receive those networks. This paper outlines the socio-economic context and the reasons that motivated the creation of a CNG project in Campina Grande, in the state of Paraiba. Technical aspects of project implementation are described, including difficulties encountered and courses of action undertaken as a result. Other aspects considered include the social and economic impact and local consumer's expectations with the arrival of new fuel. The study also considers factors relevant to the project such as the distance from the pressure measurement and regulation station, transported volumes, technology used, infrastructure and road conditions. (author)

  9. Quality study of the air at Sepetiba, Rio de Janeiro, Brazil, using Tillandsia usneoides L. (Bromeliaceae) as biomonitor; Estudo da qualidade do ar na regiao de Sepetiba usando Tillandsia usneoides L. (Bromeliaceae) como biomonitor

    Energy Technology Data Exchange (ETDEWEB)

    Pitassi, Gabriel Quadros; Julianelli, Olivia B.; Oliveira, Antonio Roberto Barboza de; Leite, Carlos Barros [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil); Zouain, Felipe; Cunha, Kenya Dias da, E-mail: kenya@ird.gov.b [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil); Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Carneiro, Luana; Medeiros, Geisa [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    This paper studies the utilization of the bromelia specie Tillandsia usneoides L. (Bromeliaceae) for characterization of the particle dispersion at urban and industrial regions. As a case study, a program will be developed for the monitoring the aerosols generated due to action of weather on the solid waste open sky stored and over the waste basin belonging to the INGA, located at Sepetiba bay. The identification of the stable metals will be done by the PIXE technique, and the radionuclides identification by alpha and gamma spectrometry. The preliminary results of aerosol samples collected at Ilha da Madeira region indicate the presence of particles containing Cd, V, K, Ca, Fe, Ti, Zn, Cu, Co and S. The variation in the percentage of each element at the points of collection suggests that there exist more than one aerosol source at the region

  10. Groundwater flow modelling in the region of the repository site of the radioactive wastes from Goiania accident-Brazil; Modelamento do fluxo de agua subterranea na regiao do repositorio dos rejeitos decorrentes do acidente radiologico de Goiania

    Energy Technology Data Exchange (ETDEWEB)

    Aquino Branco, Otavio Eurico de; Carvalho Filho, Carlos Alberto [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)

    1996-08-01

    The radioactive wastes from Goiania`s accident, with be deposited at the repository site of Abadia de Goias, located 20 km away from the city of Goiania. This paper presents a groundwater flow in confined or unconfined, heterogeneous and anisotropic porous media with variable layer thicknesses. The necessary parameters to simulate the flow were taken from technical reports and from specific studies about the region. The geological and hydrogeological studies evidence that in this area there is one aquifer type water table. The permeability coefficient evaluated for aquifer formation was 1.88x10{sup -4}cm/s and for the porosity 0.47. The average annual rate of recharge was evaluated in 0.22 m. The potentiometric map generated using the MODFLOW code showed a good a agreement between the hydraulic head simulated and that measured in the field. (author) 8 refs., 3 figs.

  11. Sequence stratigraphy of Taciba and Rio Bonito formations in Mafra, SC area, eastern Parana Basin, Brazil; Estratigrafia de sequencias das formacoes Taciba e Rio Bonito (Membro Triunfo) na regiao de Mafra/SC, leste da Bacia do Parana

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-05-01

    The Taciba and Rio Bonito ('lower' Triunfo Mbr) formations are divided into six depositional sequences based on cores, gamma-ray and electrical logs from shallow drillings from northern Santa Catarina State, Brazil. Each sequence is formed by two systems tracts, a lower one, sandy (low stand) and an upper one, shaly (high stand). The Taciba Formation has three sequences, S{sub 0} to S{sub 2}; sequence S{sub 0} has a thick turbidite sandstone at the base (Rio Segredo Member) that pinches out towards the eastern margin and even disappears in the Mafra outcrop area. Sequence S{sub 1} varies from a thin fluvial-estuarine system to a thick turbidite sandstone of a channelled fan system; S{sub 1} upper shaly system tract is marine in well PP-11, and it is glacially influenced in well PP-10. Sequence S{sub 2} is a thick sandstone body of shallow marine origin, but restricted to one well (PP-11); its upper shaly tract is dominated by massive siltstones intercalated with thin, distal tempestites. The 'lower' Triunfo Member (or 'Taciba- Triunfo transition') begins with the arrival of deltaic clastics of sequence S{sub 3} lower tract, coarsening-up from medial- to proximal delta front sandstones. Sequence S{sub 4} is quite similar to S{sub 3}, both showing sandstone pro gradation from north to south, as opposed to the southwest-sourced transgressive diamictites. Sequence S{sub 5} consists of fluvial deposits at well PP-12, and two transgressive cycles from wells PP-11 to PP-9, each one of them composed of fluvial-estuarine to marine systems. Well PP-10 is an exception, where the lower cycle presents de glaciation to marine deposits. (author)

  12. Implementation of the integrated planning process of energy resources in the administrative region of the Aracatuba in Sao Paulo, Brazil; Implementacao do processo de planejamento integrado de recursos energeticos na regiao administrativa de Aracatuba no Estado de Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Bernal, Jonathas Luiz de Oliveira; Udaeta, Miguel Edgar Morales; Grimoni, Jose Aquiles Baesso [Universidade de Sao Paulo (IEE/USP), SP (Brazil). Inst. de Eletrotecnica e Energia; Galvao, Luiz Claudio Ribeiro [Universidade de Sao Paulo (GEPEA/USP), SP (Brazil). Dept. de Energia e Automacao Eletricas. Grupo de Energia

    2008-07-01

    The project 'Novos Instrumentos para o Planejamento Energetico Regional Visando o Desenvolvimento Sustentavel' considers, through the Integrated energy Resources Planning - IRP -, to identify to the necessities and strategical expectations for the region and the elaboration of business-oriented plans in distributed resources, to evaluate the economic potential of these resources and to develop strategical projects aiming to reach the sustainable development of the west region of Sao Paulo state. Structuralized to get information organized and reliable in order to help the decision being aimed at the sustainable development and evidencing the benefits of an ample or holistic vision suggested by the IRP, the methodology of work consider phases as the consolidation of resources and technologies, research of field, determination of the potential, accomplishment of the IRP with the evaluation of the complete costs (economical, environmental, social and political respects). The study of the region points at energy resources, as much for expansion of offers as for substitution of the existing ones, considering its social, environmental respects as much as economical and political, placing them of form if to classify in space, through the geo-referring; and classifying them qualitatively, taking itself in account all characteristics previously raised. (author)

  13. Demand management by means of substitution energetics in home cooking: Costa Rica's metropolitan area; Gerenciamento da demanda mediante substituicao energetica na coccao residencial: regiao metropolitana da Costa Rica

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, Alfonso Herrera

    1996-07-01

    The electric power system management in Costa Rica is analyzed. The possibility of substitution of LPG (Liquefied Petroleum Gas) for electric power, in home cooking, are identified as one of the most important program in order to reduce increasing load peak and energy requirements in electric power system of Costa Rica. The sustain ability of the substitution program stands on the current process of electric power supply. The primary power sources used in generating electric power in rush hours are oil-based; this process is less efficient than directly using LPG for home cooking. Large scale substitution with LPG in home cooking will reduce increasing electric power demand in peak hours, reducing subsidized electricity sales, with better use of combustibles presently imported, improving the country commercial balance and preventing or postponing electric power system expansion investments. Three different perspectives have been considered in evaluating economical effectiveness in substituting power sources: user, utility and society perspectives. Due to subsidized electric power prices, residential users do not enough interest in substituting of LPG for power source; unless LPG cookers are also subsidized. However, positive results for the distribution utility are enough in order to offer these kind of incentives. Explicit treatment of these kind of programs, including the efficiency increment as an available resource for electric power utilities in Costa Rica, will avoid the implantation of most of combustion plants now planned in current National Electric Power Plant expansion program. (author)

  14. Consumption of productive electric power and value of agricultural production in Botucatu region; O consumo de energia eletrica produtiva e o valor da producao agropecuaria na regiao de Botucatu

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Paulo Andre de [Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil). Faculdade de Ciencias Agronomicas. Programa de Pos-Graduacao em Agronomia], e-mail: pauloandre@fca.unesp.br; Simon, Elias Jose [Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas. Dept. de Gestao e Tecnologia Agroindustrial], e-mail: ejsimon@fca.unesp.br

    2004-07-01

    This paper objective was to settle the electric energy consumption in the countryside and the agriculture and cattle raisin production value in the counties of the Rural Development Office (EDR) of Botucatu, in the period of 1990 to 2000, trying to establish an analysis pattern to do future studies in other regions. This pattern could be used as an analysis instrument to make decisions to implement programs that look for an increase of use of electric energy as an input to join value to the rural product. In conclusion the data adjoined as EDR region do not present enough information to the relation between the production rough value and the electric energy consumption, being necessary, therefore, its disaggregation in counties. (author)

  15. Comparative analysis of three atmospheric dispersion coefficient systems at the Angra dos Reis, RJ, region; Analise comparativa de tres sistemas de coeficientes de dispersao atmosferica na regiao de Angra dos Reis, RJ

    Energy Technology Data Exchange (ETDEWEB)

    Biagio, Rosa Maria de Souza

    1982-07-01

    A comparative analysis was made in this work among Pasquill-Gifford (PG) atmospheric dispersion coefficients and those determined at the Juelich and Karlsruhe sites with the purpose of suggesting which one would be the most applicable to the Angra site. Each one of the three systems was determined by different experiments, carried out over sites with diversified features. The systems of Juelich and Karlsruhe were obtained over sites with high surface roughness and from stacks (elevated releases), while the PG system was obtained over sites with a small surface roughness and from ground level releases. The results of the application of these systems at a complex site like Angra,which has a highly diversified structure encompassing sea, vegetation, predominance of light winds and stable stability classes, show that the PG system, the most used in the world, is still the best choice. (author)

  16. Experimental evaluation of the phases relations in the hafnium rich region of the hafnium-silicon-boron system; Avaliacao experimental das relacoes de fases na regiao rica em hafnio do sistema hafnio-silicio-boro

    Energy Technology Data Exchange (ETDEWEB)

    Gigolotti, Joao Carlos Janio; Nunes, Carlos Angelo; Coelho, Gilberto Carvalho [Universidade de Sao Paulo (DEMAR/EEL/USP), SP (Brazil)

    2010-07-01

    The technological advance has generated increasing demand for materials that can be used under high temperature, what includes intermetallic alloys MR-Si-B (MR = refractory metal) with multiphasic structures, that can also be applied in oxide environments. Thus, this work had for objective the experimentally study of the phases relations of the Hf-Si-B system at 1600 deg C, in the Hf rich region. Hf-Si-B alloys had been produced with blades of Hf (min. 99.8%), Si (min. 99.998%) and B (min. 99.5%), in the voltaic arc furnace under argon atmosphere, and heat treated at 1600 deg C under argon atmosphere. The phases had been identified by X-ray diffraction and contrast in backscattered electron imaging mode. The study determined the phases Hf{sub SS}, Hf{sub 2}Si, Hf{sub 5}Si{sub 3}, Hf{sub 3}Si{sub 2}, Hf{sub 5}Si{sub 4}, HfSi, HfSi{sub 2}, HfB and HfB{sub 2}, and the three phase fields Hf{sub SS}-Hf{sub 2}Si-HfB; HfB{sub 2}-Hf{sub 2}Si-HfB; Hf{sub 2}Si-HfB{sub 2}-Hf{sub 5}Si{sub 3}; Hf{sub 5}Si{sub 3}-HfB{sub 2}-Hf{sub 3}Si{sub 2}; Hf{sub 3}Si{sub 2}-HfB{sub 2}-Hf{sub 5}Si{sub 4}; Hf{sub 5}Si{sub 4}-HfB{sub 2}-HfSi and HfB{sub 2}-HfSi-HfSi{sub 2} in disagreement when compared with the only study found in the literature for the system at 1300 deg C. (author)

  17. Application of {sup 222} Rn as a tracer of groundwater discharge at the coastal zone of Ubatuba, Sao Paulo State, Brazil; Aplicacao de {sup 222} Rn como tracador da descarga de aguas subterraneas na regiao costeira de Ubatuba, Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Joselene de; Farias, Luciana A.; Mazzilli, Barbara P. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Dept. de Radiometria Ambiental]. E-mail: jolivei@net.ipen.br; Burnett, William C. [Florida State Univ., Tallahassee, FL (United States); Saraiva, Elisabete de S.B. e; Furtado, Valdenir V. [Sao Paulo Univ., SP (Brazil). Inst. Oceanografico. Dept. de Oceanografia Quimica e Geologica

    2002-07-01

    Submarine groundwater discharge (SGD) and recycled seawater can provide chemical constituents to coastal zone, representing an important material flux pathway from land to sea in some areas. Geochemical tracers, like {sup 222} Rn and {sup 226} Ra, are advantageous for regional-scale assessment of SGD, because their signals represent values integrated through the water column that removes small-scale variations. These radionuclides are usually enriched in groundwater compared to seawater, can be measured at very low concentrations and are conservative. This work reports preliminary results of a study carried out in a series of small embayements of Ubatuba, Sao Paulo State-Brazil, covering latitudes between 23 deg 26{sup '}S and 23 deg 46{sup '}S and longitudes between 45 deg02{sup '}W and 45 deg 11{sup '}W. The main aims of this research were to set up an analytical method to assess {sup 222} Rn and {sup 226} Ra activities in seawater samples and to apply the excess {sup 222} Rn inventories obtained to estimate the submarine groundwater discharge. Measurements made during 2001/2002 included {sup 222} Rn and {sup 226} Ra in seawater, {sup 222} Rn in sediment, seawater and sediment physical properties. (author)

  18. Sedimentary thickness and velocity in the northeast boundary of the Parana Basin with Andean earthquakes and local events; Espessura e velocidade das camadas sedimentares na borda nordeste da Bacia do Parana utilizando telessismos da regiao andina e sismos locais

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Josimar A.; Souza, Luiz M. [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Geofisica; Assumpcao, Marcelo S. [Universidade de Sao Paulo (USP), SP (Brazil)

    2008-07-01

    Deep Andean earthquakes are a suitable source of high-frequency P-waves (with good signal to noise ratio up to {approx} 10 Hz) that can be used to obtain high-resolution receiver functions at stations in intra-cratonic basins in Brazil. Receiver functions (Gaussian width 20) at five stations in the Bebedouro seismic area (NE Parana Basin) were calculated using the time domain deconvolution of Ligorria and Ammon (1999). Inter-station Rayleigh wave phase velocities were measured using local earthquakes. Joint inversion of receiver functions and Rayleigh phase velocities provided reasonably well constrained S-wave velocity profiles. Shallow seismic refraction surveys were used to fix the velocities of the surface layers during the inversion. The area is characterized by a thin surface layer of sandstones ({approx}60 m), followed by a {approx}500 m thick basalt layer. Beneath the basalts, low-velocity layers define another sedimentary sequence. These features are consistent with the expected values based on well data at regional distances and confirm the usefulness of high-frequency receiver functions to study sedimentary basins. (author)

  19. Infrared Spectroscopy in the region X-Ray Diffraction and the mineral trioxide aggregate; Espectroscopia na regiao do infravermelho e difracao de raios-X do agregado trioxido mineral

    Energy Technology Data Exchange (ETDEWEB)

    Barros, C.M.B.; Oliveira, S.V.; Silva, M.C.; Cartaxo, J.M.; Fook, M.V.L., E-mail: criseuda@uol.com.br [Universidade Federal de Campina Grande (UFCG), Campina Grande, PB (Brazil). Departamento de Engenharia de Materiais

    2011-07-01

    In the nineties was introduced into the search field of biomaterials to mineral trioxide aggregate (MTA). It is a derivative of Portland cement with similar chemical properties and was initially developed as a root filling material in dentistry. This material is presented characteristics of mechanical, physical and biological meaningful when applied to biological environment. It was used to search a commercial MTA manipulated with distilled water and propylene glycol in order to verify chemical composition, infrared absorption bands and stages in the samples. The MTA has been characterized by XRF, XRD and FTIR. In X-ray fluorescence was found that the MTA has a characteristic composition of hydraulic cement. Through FTIR MTA mixed with water presents an enlargement in the absorption bands in the region 1467 and 873 cm-1. By means of XRD showed that there is no presence of toxic materials in the majority and secondary phases. (author)

  20. Characterization and technological properties of mineral clays used in the Southwest of Parana and West of Santa Catarina states; Caracterizacao e propriedades tecnologicas de argilas utilizadas na regiao sudoeste do Parana e oeste de Santa Catarina

    Energy Technology Data Exchange (ETDEWEB)

    Valdameri, C.Z.; Ciesca, D.F., E-mail: cledison@unipar.br [Universidade Paranaense (UNIPAR), Francisco Beltrao, PR (Brazil). Departamento de Engenharia Civil; Zatta, L. [Universidade Tecnologica Federal do Parana (UTFPR), Pato Branco, PR (Brazil). Departtamento de Quimica; Anaissi, F.J. [Universidade Estadual do Centro-Oeste (UNICENTRO), Guarapuava, PR (Brazil). Departamento de Quimica

    2014-07-01

    This paper aims to characterize clay minerals used in the ceramic industry in southwestern region of Parana and west of Santa Catarina states. The precursors used were the same used by industries in these regions for the production of bricks. The precursors were characterized,preliminary results are shown with respect to structural, chemical and physical precursors (XRD, EDS and plasticity). The specimens were characterized for technological burning properties: linear shrinkage, water absorption, flexural tension and density. The results show that the clays present Typical chemical composition of raw clay, however, the evaluation of technological properties after burning indicate negative results to be applied to the manufacture of red ceramic because did not meet the regulatory requirements. (author)

  1. A critical analysis of the 'Programa Luz Para Todos' for the electrification of remote communities in the Amazon region; Uma analise critica do Programa Luz Para Todos para a eletrificacao de comunidades isoladas na regiao Amazonica

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Andre Frazao [Fundacao de Amparo a Pesquisa do Estado do Amazonas (FAPEAM), Manaus, AM (Brazil); Lopes, Davi Gabriel; Cavaliero, Carla Kazue Nakao [Universidade Estadual de Campinas (FEM/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica

    2010-07-01

    This article presents a critical review of 'Luz para Todos' (LpT) as a rural electricity deployment program and its viability as a starter for a development process to isolated communities from Amazon region. We analyzed the functionality using data from the beginning of the program until 2009, as well the methodology and organization of the investments over 'Luz para Todos' program as a development starter, preferably sustainable, for the isolated communities from Amazon region. We concluded that a discussion is mandatory, as well a review of some important points, such as estimation of available financial resources; mechanisms used to motivate electric utilities that serve the isolated communities especially in the Amazon region; and the relationship between energy and development proposed by the program. (author)

  2. Oil seepage detection technique as a tool to hydrocarbon prospecting in offshore Campos Basin-Brazil; Deteccao de exsudacoes de oleo como uma ferramenta de prospeccao de hidrocarbonetos na regiao maritima da Bacia de Campos - Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Castilho, Jose G.; Brito, Ademilson F. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Modelagem de Bacias (LAB2M); Landau, Luiz [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Metodos Computacionais em Engenharia (LAMCE)

    2004-07-01

    With a proven capacity to identify oil slicks in offshore regions, RADARSAT-1 imagery can be useful for oil exploration purposes. The paper discusses the seepage detection method at Campos Basin, offshore Rio de Janeiro State, which is responsible for 80% of the Brazilian production of oil and gas. It is known that the horizontal migration of petroleum can occurs over tens or even hundreds of kilometers, where the source rock placed in more deep locations can be linked with shallow reservoirs or traps and even reach the ocean. It means that seepage can provide information for risking petroleum charge at basin scales, and cannot have a direct relation with the geographical position of the interpreted seeps and possible filled prospects. A good understanding of the geology, and hence the petroleum systems of a basin is the key to use seepage in exploration. The work is divided into three main steps. First step were select oil seepages interpreted at Campos Basin where is found several giant petroleum fields. Second, the geology of the study area and its structural and stratigraphic features were analyzed, in order to identify possible migration pathways related to faults generated by halokinesis. Another important aspect is the presence of 'windows' or ducts in the evaporates beds allowing the contact between the section that contains source rocks and the turbidities reservoirs, that contain the majority of the oil discovers. All these features were interpreted based on a regional dip seismic line (203 - 76), and a geologic cross section with E-W orientation, showing the structure of the Marlim Field. Finally, all the information was integrated in a Geographical Information System (GIS), and then analyzed in an interdisciplinary environment, with the intention to link possible routes of oil migration to post-evaporites reservoirs or to interpreted seeps. (author)

  3. Thermodynamic analysis of mechanical behaviour in the elastic region of blends of recycled poly (ethylene terephthalate) and recycled polyolefins; Analise termodinamica do comportamento mecanico na regiao elastica de blendas de poli (tereftalato de etileno) reciclado e poliolefinas recicladas

    Energy Technology Data Exchange (ETDEWEB)

    Marconcini, Jose M. [Universidade Federal do Parana Univ. (UFPR), Curitiba, PR (Brazil). Inst. de Tecnologia para o Desenvolvimento; Ruvolo Filho, Adhemar [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Dept. de Quimica]. E-mail: adhemar@power.ufscar.br

    2006-10-15

    This work describes the study using mechanical tests with the blend of recycled poly(ethylene terephthalate) (PET) and recycled polyolefin with and without the addition of polypropylene grafted with maleic anhydride and poly(ethylene-co-octene-1). A thermodynamic approach based on the Helmholtz work function was applied in the analysis of mechanical tests, correlating the effects of energy storage and from the compatibilizer on the elastic region of the materials. For the system studied, the polyolefin-rich region shows higher storage of elastic energy corroborating the morphology images obtained from SEM analysis. The thermodynamic analysis seems a useful tool to evaluate the compatibilizer effect in polymeric immiscible blends. In this work, more specifically, this method was used to analyze the mechanical behavior of different compositions of recycled polymeric commodity materials. (author)

  4. Presence of uraninite associated with copper and iron minerals in the region of the Serra do Sossego, north of Brazil; Presenca de uraninita associada a minerais de cobre e ferro na regiao da Serra do Sossego, norte do Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Salas, Humberto Terrazas; Murta, Clecio Campi [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)]. E-mail: salasht@urano.cdtn.br; Nalini Junior, Herminio Arias [Ouro Preto Univ., MG (Brazil). Escola de Minas. Dept. de Geologia

    2000-07-01

    In this work, results on studies carried out on radioactive samples from Serra do Sossego (close to Carajas , in the state of Para) are reported. According to studies of mineralogical characterization, involving petrographic and mineralographic analysis, complemented by other specific techniques, it was possible to determine the forms of presentation of the uraninite (UO{sub 2}), and its respective association to sulphide minerals rich in copper, primarily those with greater concentration, such as bornite (Cu{sub 5}FeS{sub 4}) and, secondarily, calcopirite (CuFeS{sub 2}). These sulphides come associated to abundant iron oxide, such as magnetite (Fe{sub 3}O{sub 4}) and its alteration products, and also assorted silicate minerals. From the results of autoradiographic tests and an electronic microprobe, a significant amount of uraninite was determined, showing that sulfites and oxides that occur associated to the uranium mineral, include this element in their crystalline lattices. (author)

  5. Evaluation of fracture toughness of DIN 15 Mo3 steel in the transition region, by master curve; Avaliacao da tenacidade a fratura do aco DIN 15 Mo3 na regiao de transicao, atraves da curva mestra

    Energy Technology Data Exchange (ETDEWEB)

    Rabello, Emerson G.; Martins, Geraldo de P.; Gomes, Paulo de T.V. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)

    2000-07-01

    The characterization of fracture behavior in the ductile-to-brittle transition for ferritic steels is a hard task because fracture toughness values exhibit extensive scatter and severe size and geometry effects. To overcome this problem in practice, the ASME Code has provided reference curves that give estimates of toughness versus temperature. These curves represent lower envelopes to a large set of fracture toughness experimental data for several heats of steel. Therefore, the fracture toughness values obtained from these curves are in general too conservative. In the last decade, a new methodology, formalized in the ASTM standard method E1921-97, has revolutionized the approach used to characterize transition fracture behavior and has given a rationale for treating the several factors that influence the scatter in the results. Statistical models are used to define a transition curve, called Master Curve, and the transition temperature of a given material is stated by a parameter called reference Temperature (T{sub o}). In this work, the Master Curve approach is applied to characterize the transition behavior of DIN 15 Mo3 steel. (author)

  6. Electrical resistivity of ceramic-metal composite materials in the percolation region: application in crucibles for induction furnaces; Resistividade eletrica de materiais compositos do tipo ceramica-metal na regiao de percolacao: aplicacao em cadinhos para fornos de inducao

    Energy Technology Data Exchange (ETDEWEB)

    Sene, Frank Ferrer

    1997-07-01

    Ceramic composite materials were produced by mixing powders of Partially Stabilized (PSZ) with titanium, niobium or nickel, and cristobalite with titanium. Pellets were produced by uniaxially pressing the material followed by cold isostatic pressing and finally sintering at 1600 deg C for 1,5 hours in argon. The metal content was varied in the range of 0-40 volume percent (v/o). Electrical resistivity measurements were performed in the temperature range of 25 - 700 deg C. Samples containing metallic inclusions above 25 v/o show the predominance of electronic type conducting. For samples with metallic inclusion below 25 v/o, a typically ionic conduction behavior has been observed. PSZ-Ti and PSZ-Ni samples containing 25 v/o of metallic inclusions show an insulator - conductor transition in a given temperature range. Cristobalite samples containing 30 v/o of titanium show a conductor - insulator transition also in a specific temperature range. Tests performed in an induction furnace showed that samples containing metallic inclusions above 25 v/o had self-heated when exposed to electro magnetic fields in the range of radio frequency (r.f.) Crucibles of PSZ-Ti were made by slip casting followed by sintering at 1600 deg C for 1.5 hours in argon. These crucibles were exposed to electromagnetic fields in the r.f. range and the maximum temperature reached was 1350 deg C. Microstructure characterization was performed on those materials by X-ray diffraction, EDS, optical and scanning electron microscopy. (author)

  7. Neutron spectra produced by moderating an isotopic neutron source

    International Nuclear Information System (INIS)

    Carrillo Nunnez, Aureliano; Vega Carrillo, Hector Rene

    2001-01-01

    A Monte Carlo study has been carried out to determine the neutron spectra produced by an isotopic neutron source inserted in moderating media. Most devices used for radiation protection have a response strongly dependent on neutron energy. ISO recommends several neutron sources and monoenergetic neutron radiations, but actual working situations have broad spectral neutron distributions extending from thermal to MeV energies, for instance, near nuclear power plants, medical applications accelerators and cosmic neutrons. To improve the evaluation of the dosimetric quantities, is recommended to calibrate the radiation protection devices in neutron spectra which are nearly like those met in practice. In order to complete the range of neutron calibrating sources, it seems useful to develop several wide spectral distributions representative of typical spectra down to thermal energies. The aim of this investigation was to use an isotopic neutron source in different moderating media to reproduce some of the neutron fields found in practice. MCNP code has been used during calculations, in these a 239PuBe neutron source was inserted in H2O, D2O and polyethylene moderators. Moderators were modeled as spheres and cylinders of different sizes. In the case of cylindrical geometry the anisotropy of resulting neutron spectra was calculated from 0 to 2 . From neutron spectra dosimetric features were calculated. MCNP calculations were validated by measuring the neutron spectra of a 239PuBe neutron source inserted in a H2O cylindrical moderator. The measurements were carried out with a multisphere neutron spectrometer with a 6LiI(Eu) scintillator. From the measurements the neutron spectrum was unfolded using the BUNKIUT code and the UTA4 response matrix. Some of the moderators with the source produce a neutron spectrum close to spectra found in actual applications, then can be used during the calibration of radiation protection devices

  8. Workshop on neutron spin-echo

    Energy Technology Data Exchange (ETDEWEB)

    Aynajian, P.; Habicht, K.; Keller, Th.; Keimer, B.; Mezei, F.; Monkenbusch, M.; Allgaier, J.; Richter, D.; Fetters, L.J.; Muller, K.; Kreiling, S.; Dehnicke, K.; Greiner, A.; Ehlers, G.; Arbe, A.; Colmenero, J.; Richter, D.; Farago, B.; Monkenbusch, M.; Ohl, M.; Butzek, M.; Kozielewski, T.; Monkenbusch, M.; Richter, D.; Pappas, C.; Hillier, A.; Manuel, P.; Cywinski, R.; Bentley, P.; Alba, M.; Mezei, F.; Campbell, I.A.; Zimmermann, U.; Ellis, J.; Jobic, H.; Pickup, R.M.; Pappas, C.; Farago, B.; Cywinski, R.; Haussler, W.; Holderer, O.; Frielinghaus, H.; Byelov, D.; Monkenbusch, M.; Allgaier, J.; Richter, D.; Egger, H.; Hellweg, Th.; Malikova, N.; Cadene, A.; Marry, V.; Dubois, E.; Turq, P.; Gardner, J.S.; Ehlers, G.; Bramwell, St.S.; Grigoriev, S.; Kraan, W.; Rekveldt, T.; Bouwman, W.; Van Dijk, N.; Falus, P.; Vorobiev, A.; Major, J.; Felcher, G.P.; Te-velthuis, S.; Dosch, H.; Vorobiev, A.; Dridi, M.H.; Major, J.; Dosch, H.; Falus, P.; Felcher, G.P.; Te Velthuis, S.G.E.; Bleuel, M.; Broell, M.; Lang, E.; Littrell, K.; Gahler, R.; Lal, J.; Lauter, H.; Toperverg, B.; Lauter, V.; Jernenkov, M.; Stueber, S.; Enderle, M.; Janoschek, M.; Keller, Th.; Klimko, S.; Boeni, P.; Nagao, M.; Yamada, N.; Kawabata, Y.; Seto, H.; Takeda, T.; Yoshizawa, H.; Yoshida, K.; Yamaguchi, T.; Bellissent-Funel, M.C.; Longeville, St

    2005-07-01

    This document gathers the abstracts of most papers presented at the workshop. Neutron spin-echo (NSE) spectroscopy is a well established technique with a growing expert user community, the aim of the meeting was to discuss the latest achievements in neutron spin-echo science and instrumentation. One of the applications presented is the investigation on the microscopic scale of the dynamics of water in montmorillonite clays with Na{sup +} and Cs{sup +} ions in monolayer and bilayer states. The NSE technique has been used in the normal and resonance modes. NSE results show consistently slower dynamics (higher relaxation times) than both time-of-flight technique (TOF) and classical molecular dynamics simulations (MD). In the present TOF and NSE experiments, anisotropy of the water motion in the interlayer is almost impossible to detect, due to the use of powder samples and insufficient resolution. (A.C.)

  9. Experimental research of neutron yield and spectrum from deuterium gas-puff z-pinch on the GIT-12 generator at current above 2 MA

    Science.gov (United States)

    Cherdizov, R. K.; Fursov, F. I.; Kokshenev, V. A.; Kurmaev, N. E.; Labetsky, A. Yu; Ratakhin, N. A.; Shishlov, A. V.; Cikhardt, J.; Cikhardtova, B.; Klir, D.; Kravarik, J.; Kubes, P.; Rezac, K.; Dudkin, G. N.; Garapatsky, A. A.; Padalko, V. N.; Varlachev, V. A.

    2017-05-01

    The Z-pinch experiments with deuterium gas-puff surrounded by an outer plasma shell were carried out on the GIT-12 generator (Tomsk, Russia) at currents of 2 MA. The plasma shell consisting of hydrogen and carbon ions was formed by 48 plasma guns. The deuterium gas-puff was created by a fast electromagnetic valve. This configuration provides an efficient mode of the neutron production in DD reaction, and the neutron yield reaches a value above 1012 neutrons per shot. Neutron diagnostics included scintillation TOF detectors for determination of the neutron energy spectrum, bubble detectors BD-PND, a silver activation detector, and several activation samples for determination of the neutron yield analysed by a Sodium Iodide (NaI) and a high-purity Germanium (HPGe) detectors. Using this neutron diagnostic complex, we measured the total neutron yield and amount of high-energy neutrons.

  10. Neutron irradiation of seeds

    International Nuclear Information System (INIS)

    1967-01-01

    Neutrons are a valuable type of ionizing radiation for seed irradiation and radiobiological studies and for inducing mutations in crop plants. In experiments where neutrons are used in research reactors for seed irradiation it is difficult to measure the dose accurately and therefore to establish significant comparisons between experimental results obtained in various reactors and between repeated experiments in the same reactor. A further obstacle lies in the nature and response of the seeds themselves and the variety of ways in which they are exposed in reactors. The International Atomic Energy Agency decided to initiate international efforts to improve and standardize methods of exposing seeds in research reactors and of measuring and reporting the neutron dose. For this purpose, an International Neutron Seed Irradiation Programme has been established. The present report aims to give a brief but comprehensive picture of the work so far done in this programme. Refs, figs and tabs

  11. Precision Polarization of Neutrons

    Science.gov (United States)

    Martin, Elise; Barron-Palos, Libertad; Couture, Aaron; Crawford, Christopher; Chupp, Tim; Danagoulian, Areg; Estes, Mary; Hona, Binita; Jones, Gordon; Klein, Andi; Penttila, Seppo; Sharma, Monisha; Wilburn, Scott

    2009-05-01

    Determining polarization of a cold neutron beam to high precision is required for the next generation neutron decay correlation experiments at the SNS, such as the proposed abBA and PANDA experiments. Precision polarimetry measurements were conducted at Los Alamos National Laboratory with the goal of determining the beam polarization to the level of 10-3 or better. The cold neutrons from FP12 were polarized using optically polarized ^3He gas as a spin filter, which has a highly spin-dependent absorption cross section. A second ^ 3He spin filter was used to analyze the neutron polarization after passing through a resonant RF spin rotator. A discussion of the experiment and results will be given.

  12. Neutron personnel dosimetry

    International Nuclear Information System (INIS)

    Griffith, R.V.

    1981-01-01

    The current state-of-the-art in neutron personnel dosimetry is reviewed. Topics covered include dosimetry needs and alternatives, current dosimetry approaches, personnel monitoring devices, calibration strategies, and future developments

  13. Personnel neutron dosimetry

    International Nuclear Information System (INIS)

    Hankins, D.

    1982-04-01

    This edited transcript of a presentation on personnel neutron discusses the accuracy of present dosimetry practices, requirements, calibration, dosemeter types, quality factors, operational problems, and dosimetry for a criticality accident. 32 figs

  14. The intense neutron generator

    International Nuclear Information System (INIS)

    Lewis, W.B.

    1966-01-01

    The presentation discusses both the economic and research contexts that would be served by producing neutrons in gram quantities at high intensities by electrical means without uranium-235. The revenue from producing radioisotopes is attractive. The array of techniques introduced by the multipurpose 65 megawatt Intense Neutron Generator project includes liquid metal cooling, superconducting magnets for beam bending and focussing, super-conductors for low-loss high-power radiofrequency systems, efficient devices for producing radiofrequency power, plasma physics developments for producing and accelerating hydrogen, ions at high intensity that are still far out from established practice, a multimegawatt high voltage D.C. generating machine that could have several applications. The research fields served relate principally to materials science through neutron-phonon and other quantum interactions as well as through neutron diffraction. Nuclear physics is served through μ-, π- and K-meson production. Isotope production enters many fields of applied research. (author)

  15. High energy neutron generator

    International Nuclear Information System (INIS)

    Barjon, R.; Breynat, G.

    1987-01-01

    This patent describes a generator of fast neutrons only slightly contaminated by neutrons of energy less than 15 MeV, comprising a source of charged particles of energy equal to at least 15 MeV, a target made of lithium deuteride, and means for cooling the target. The target comprises at least two elements placed in series in the path of the charged particles and separated from each other, the thickness of each of the elements being selected as a function of the average energy of the charged particles emitted from the source and the energy of the fast neutrons to be generated such that neutrons of energy equal to at least 15 MeV are emitted in the forward direction in response to the bombardment of the target from behind by the charged particles. The target cooling means comprises means for circulating between and around the elements a gas which does not chemically react with lithium deuteride

  16. Neutron signal transfer analysis

    CERN Document Server

    Pleinert, H; Lehmann, E

    1999-01-01

    A new method called neutron signal transfer analysis has been developed for quantitative determination of hydrogenous distributions from neutron radiographic measurements. The technique is based on a model which describes the detector signal obtained in the measurement as a result of the action of three different mechanisms expressed by signal transfer functions. The explicit forms of the signal transfer functions are determined by Monte Carlo computer simulations and contain only the distribution as a variable. Therefore an unknown distribution can be determined from the detector signal by recursive iteration. This technique provides a simple and efficient tool for analysis of this type while also taking into account complex effects due to the energy dependency of neutron interaction and single and multiple scattering. Therefore this method provides an efficient tool for precise quantitative analysis using neutron radiography, as for example quantitative determination of moisture distributions in porous buil...

  17. Neutrons for industry

    International Nuclear Information System (INIS)

    Petry, W.

    2015-01-01

    Neutrons are a unique tool for materials science, from hard to soft matter. This uniqueness relies on the privileged penetration of neutrons in any kind of matter, their particular contrast for different elements/isotopes, their capability to characterize in situ, in operation and in real time. Often enough neutron research explains the functionality of materials and work pieces by their atomistic foundation and opens the way for optimization of the functionality. In this paper the author reviews some new applications of neutron irradiation in industry: homogenous doping for power electronics; the selection of the right candidates for hydrogen storage materials; the optimization of Li-ion batteries and organic solar cells; the 3-dimensional determination of residual stresses without damaging the specimen. Concerning medicine there were some advances for the production of some isotopes like Lu 177 or Mo 99 -Tc 99m

  18. Cylindrical neutron generator

    Science.gov (United States)

    Leung, Ka-Ngo [Hercules, CA

    2008-04-22

    A cylindrical neutron generator is formed with a coaxial RF-driven plasma ion source and target. A deuterium (or deuterium and tritium) plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical neutron generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which contain many slots. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired. The plasma generator may be in the center and the neutron target on the outside, or the plasma generator may be on the outside and the target on the inside. In a nested configuration, several concentric targets and plasma generating regions are nested to increase the neutron flux.

  19. Studsvik thermal neutron facility

    International Nuclear Information System (INIS)

    Pettersson, O.A.; Larsson, B.; Grusell, E.; Svensson, P.

    1992-01-01

    The Studsvik thermal neutron facility at the R2-0 reactor originally designed for neutron capture radiography has been modified to permit irradiation of living cells and animals. A hole was drilled in the concrete shielding to provide a cylindrical channel with diameter of 25.3 cm. A shielding water tank serves as an entry holder for cells and animals. The advantage of this modification is that cells and animals can be irradiated at a constant thermal neutron fluence rate of approximately 10 9 n cm -2 s -1 (at 100 kW) without stopping and restarting the reactor. Topographic analysis of boron done by neutron capture autoradiography (NCR) can be irradiated under the same conditions as previously

  20. Opportunities in Neutron Science

    Science.gov (United States)

    Fernandez-Baca, Jaime

    2010-03-01

    National Laboratories often have unique facilities that cannot be normally found at universities, and that provide unique opportunities to perform research using world class instrumentation in collaboration with teams of experts. This synergy of expertise and world-class facilities also offers unique opportunities for mentoring and training of students in settings different from the university environment. In this talk I will discuss the opportunities of scientific research, mentoring and training at the Spallation Neutron Source (SNS) and the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. The SNS is the world's most intense pulsed accelerator-based neutron source, the HFIR is the highest flux reactor-based neutron source for condensed matter research in the United States, the combination of these provides neutron scattering capabilities unavailable anywhere else in the world. The SNS and the HFIR at ORNL are funded by the Division of Scientific User Facilities, Office of Basic Energy Sciences, US. Department of Energy.

  1. Neutron beam instruments for neutron science at HANARO

    International Nuclear Information System (INIS)

    Kim, Y.K.

    2009-01-01

    HANARO (Highly Advanced Neutron Application Reactor) came on line as the first criticality achieved in 1995. Since then a lot of experimental facilities for various utilizations have been gradually installed over the years up until now. Neutron science actually began with the neutron radiography facility completed in 1997. Thereafter, a series of thermal neutron beam instruments have been added and opened for the users. Some of them are high resolution power diffractometer, four circle diffractometer, small angle neutron spectrometer, and vertical-type reflectometer. The cold neutron research facility project was initiated in 2003, which envisions installation of cold neutron source, related systems, 5 neutron guides, and 7 instruments to satisfy the needs of cold neutron beam as the indispensable tool in NT, BT and other emerging technologies. Cold neutron guide building had been completed in October, 2008. Cold neutrons are planned to be produced later this year. Installations of neutron guides and associated instruments are to be finalized by the middle of 2010, ready for use. A 20 m detector vacuum tank and 20 m pre-sample flight path for 40 m SANS are already in place at the guide hall. Currently, there are about 450 users working with thermal neutron instruments. Once cold neutron instruments are available, we expect the number of users will double within next 3 years. (author)

  2. Small-angle neutron scattering study of sodium cholate and sodium ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Small angle neutron scattering (SANS) measurements of D2O solutions. (0⋅1 M) of sodium cholate (NaC) and sodium deoxycholate (NaDC) were carried out at T = 298 K. Under compositions very much above the critical micelle concentration. (CMC), the bile salt micelle size growths were monitored by adopting ...

  3. Neutron diffraction investigation of liquid alkali metal-gallium alloys. Giant cluster formation?

    NARCIS (Netherlands)

    Alvarez, M; Lomba, E; Verkerk, P; van der Aart, SA; Bionducci, M; Mirebeau, [No Value; van der Lugt, W

    Neutron diffraction experiments were performed on the liquid alloys NaGa, NaGa3, KGa3 and CsGa3. The structure factors of KGa3 and CsGa3 display prepeaks at small wavenumbers (0.64 and 0.61 (A) over circle -1, respectively). This may indicate the existence of extremely large aggregates of atoms in

  4. Scope of neutron interferometry

    International Nuclear Information System (INIS)

    Rauch, H.

    1978-01-01

    This paper deals with the interferometry of well separated coherent beams, where the phase of the beams can be manipulated individually. The basic equation of the dynamical neutron diffraction theory are recalled. The various contributions to the interaction of as low neutron with its surroundings are discussed: the various terms denote the nuclear, magnetic, electromagnetic, intrinsic, gravitational, and weak interaction respectively. Applications to nuclear physics, fundamental physics and solid state physics are successively envisaged

  5. Pulsed spallation neutron sources

    International Nuclear Information System (INIS)

    Carpenter, J.M.

    1996-01-01

    This paper reviews the early history of pulsed spallation neutron source development ar Argonne and provides an overview of existing sources world wide. A number of proposals for machines more powerful than currently exist are under development, which are briefly described. The author reviews the status of the Intense Pulsed Neutron Source, its instrumentation, and its user program, and provide a few examples of applications in fundamental condensed matter physics, materials science and technology

  6. Pulsed spallation Neutron Sources

    International Nuclear Information System (INIS)

    Carpenter, J.M.

    1994-01-01

    This paper reviews the early history of pulsed spallation neutron source development at Argonne and provides an overview of existing sources world wide. A number of proposals for machines more powerful than currently exist are under development, which are briefly described. The author reviews the status of the Intense Pulsed Neutron Source, its instrumentation, and its user program, and provides a few examples of applications in fundamental condensed matter physics, materials science and technology

  7. Introduction to neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, W.E. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-11-01

    We give here an introduction to the theoretical principles of neutron scattering. The relationship between scattering- and correlation-functions is particularly emphasized. Within the framework of linear response theory (justified by the weakness of the basic interaction) the relation between fluctuation and dissipation is discussed. This general framework explains the particular power of neutron scattering as an experimental method. (author) 4 figs., 4 refs.

  8. Neutron ion temperature measurement

    International Nuclear Information System (INIS)

    Strachan, J.D.; Hendel, H.W.; Lovberg, J.; Nieschmidt, E.B.

    1986-11-01

    One important use of fusion product diagnostics is in the determination of the deuterium ion temperature from the magnitude of the 2.5 MeV d(d,n) 3 He neutron emission. The detectors, calibration methods, and limitations of this technique are reviewed here with emphasis on procedures used at PPPL. In most tokamaks, the ion temperature deduced from neutrons is in reasonable agreement with the ion temperature deduced by other techniques

  9. NEUTRON FLUX INTENSITY DETECTION

    Science.gov (United States)

    Russell, J.T.

    1964-04-21

    A method of measuring the instantaneous intensity of neutron flux in the core of a nuclear reactor is described. A target gas capable of being transmuted by neutron bombardment to a product having a resonance absorption line nt a particular microwave frequency is passed through the core of the reactor. Frequency-modulated microwave energy is passed through the target gas and the attenuation of the energy due to the formation of the transmuted product is measured. (AEC)

  10. Forensic neutron activation analysis

    International Nuclear Information System (INIS)

    Kishi, T.

    1987-01-01

    The progress of forensic neutron activation analysis (FNAA) in Japan is described. FNAA began in 1965 and during the past 20 years many cases have been handled; these include determination of toxic materials, comparison examination of physical evidences (e.g., paints, metal fragments, plastics and inks) and drug sample differentiation. Neutron activation analysis is applied routinely to the scientific criminal investigation as one of multielement analytical techniques. This paper also discusses these routine works. (author) 14 refs

  11. Neutrons and fusion

    International Nuclear Information System (INIS)

    Maynard, C.W.

    1976-01-01

    The production of energy from fusion reactions does not require neutrons in the fundamental sense that they are required in a fission reactor. Nevertheless, the dominant fusion reaction, that between deuterium and tritium, yields a 14 MeV neutron. To contrast a fusion reactor based on this reaction with the fission case, 3 x 10 20 such neutrons produced per gigawatt of power. This is four times as many neutrons as in an equivalent fission reactor and they carry seven times the energy of the fission neutrons. Thus, they dominate the energy recovery problem and create technological problems comparable to the original plasma confinement problem as far as a practical power producing device is concerned. Further contrasts of the fusion and fission cases are presented to establish the general role of neutrons in fusion devices. Details of the energy deposition processes are discussed and those reactions necessary for producing additional tritium are outlined. The relatively high energy flux with its large intensity will activate almost any materials of which the reactor may be composed. This activation is examined from the point of view of decay heat, radiological safety, and long-term storage. In addition, a discussion of the deleterious effects of neutron interactions on materials is given in some detail; this includes the helium and hydrogen producing reactions and displacement rate of the lattice atoms. The various materials that have been proposed for structural purposes, for breeding, reflecting, and moderating neutrons, and for radiation shielding are reviewed from the nuclear standpoint. The specific reactions of interest are taken up for various materials and finally a report is given on the status and prospects of data for fusion studies

  12. Quantum physics with neutrons

    International Nuclear Information System (INIS)

    Durstberger, K.; Hasegawa, Y.; Klepp, J.; Sulyok, G.; Rauch, H.

    2008-01-01

    Full text: Fundamental quantum properties like quantum coherence and entanglement are among the most interesting features of quantum mechanics. The physical system of interest is the (massive) neutron subjected to interferometric and polarimetric measurements. Neutrons are proper objects for a study of quantum mechanical behavior: they allow for rather easy experimental control and the neutron spin is the simplest two-level system with easy manipulation by magnetic fields. In combination with interferometric measurements the system has enough intrinsic richness to show interesting quantum features such as entanglement. The coupling of the neutron to an external magnetic field allows for selective manipulations of the spinor quantum states. This can be used, on the one hand, to create entangled states where the entanglement occurs between different degrees of freedom (e.g. spin and path) and, on the other hand, one can introduce dephasing and decoherence by varying magnetic fields. We investigate different kinds of entanglement for the neutron system and mechanisms for decoherence and dephasing. We discuss weak measurements and their realization for neutrons where information about the system can be revealed without disturbing the system too much. Beyond the theoretical work we develop experimental strategies to check the results directly in suitably designed experiments. The experimental work is done at the Institute Laue-Langvine (ILL) in Grenoble, France. (author)

  13. Neutron flux monitoring device

    International Nuclear Information System (INIS)

    Shimazu, Yoichiro.

    1995-01-01

    In a neutron flux monitoring device, there are disposed a neutron flux measuring means for outputting signals in accordance with the intensity of neutron fluxes, a calculation means for calculating a self power density spectrum at a frequency band suitable to an object to be measured based on the output of the neutron flux measuring means, an alarm set value generation means for outputting an alarm set value as a comparative reference, and an alarm judging means for comparing the alarm set value with the outputted value of the calculation means to judge requirement of generating an alarm and generate an alarm in accordance with the result of the judgement. Namely, the time-series of neutron flux signals is put to fourier transformation for a predetermined period of time by the calculation means, and from each of square sums for real number component and imaginary number component for each of the frequencies, a self power density spectrum in the frequency band suitable to the object to be measured is calculated. Then, when the set reference value is exceeded, an alarm is generated. This can reliably prevent generation of erroneous alarm due to neutron flux noises and can accurately generate an alarm at an appropriate time. (N.H.)

  14. Neutrons for materials science

    International Nuclear Information System (INIS)

    Windsor, C.G.; Allen, A.J.; Hutchings, M.T.; Sayers, C.M.; Sinclair, R.N.; Schofield, P.; Wright, C.J.

    1984-12-01

    The discussion will be limited to applied materials research performed on a customer/contractor basis. The information obtained using neutrons must therefore compete both scientifically and financially with information obtained using other techniques, particularly electron microscopy, X-ray, NMR, infra-red and Raman spectroscopy. It will be argued that the unique nature of the information gained from neutrons often outweighs the undoubted difficulties of access to neutron beams. Examples are given. Small angle scattering has emerged as the neutron technique of widest application in applied materials research. The penetration of neutron beams through containment vessels, as well as through the sample, allows the measurement of 'in situ' time dependent experiments within a furnace, cryostat, pressure vessel or chemical reactor vessel. High resolution powder diffraction is another technique with wide applications. Structural studies are possible on increasing complex phases. The structure and volume fraction of minority phases can be measured at levels appreciably below that possible by X-ray diffraction. A rapidly growing field at present is the measurement of internal strains through the small shifts in lattice spacing. Inelastic scattering measurements exploit the unique property of neutrons to measure the orientations of vibrating molecules. (author)

  15. Neutron Nucleic Acid Crystallography.

    Science.gov (United States)

    Chatake, Toshiyuki

    2016-01-01

    The hydration shells surrounding nucleic acids and hydrogen-bonding networks involving water molecules and nucleic acids are essential interactions for the structural stability and function of nucleic acids. Water molecules in the hydration shells influence various conformations of DNA and RNA by specific hydrogen-bonding networks, which often contribute to the chemical reactivity and molecular recognition of nucleic acids. However, X-ray crystallography could not provide a complete description of structural information with respect to hydrogen bonds. Indeed, X-ray crystallography is a powerful tool for determining the locations of water molecules, i.e., the location of the oxygen atom of H2O; however, it is very difficult to determine the orientation of the water molecules, i.e., the orientation of the two hydrogen atoms of H2O, because X-ray scattering from the hydrogen atom is very small.Neutron crystallography is a specialized tool for determining the positions of hydrogen atoms. Neutrons are not diffracted by electrons, but are diffracted by atomic nuclei; accordingly, neutron scattering lengths of hydrogen and its isotopes are comparable to those of non-hydrogen atoms. Therefore, neutron crystallography can determine both of the locations and orientations of water molecules. This chapter describes the current status of neutron nucleic acid crystallographic research as well as the basic principles of neutron diffraction experiments performed on nucleic acid crystals: materials, crystallization, diffraction experiments, and structure determination.

  16. Neutron diffraction principles

    International Nuclear Information System (INIS)

    Granada, Jose R.

    1998-01-01

    Neutron as research element contributes at present to the understanding and development of almost all aspects related to basic and applied science, even with the relative inaccessibility of neutron sources and the fact that the most intense sources still provide relatively weak neutron beams. The initial discovery of these potentialities and the first works that allowed to convert the neutronic techniques into the actual powerful experimental tool, have been recognized by the adjudication of the Nobel Prize in Physics 1994 to Professors B. Brockhouse and C. Shull. Unfortunately, these tools have not been exploited neither in our country, nor in the Latin American area, with the exception of very limited applications in Materials Science. Although the theoretical principles of neutron scattering techniques have been treated in texts and review works, the aim of this work is to present a compact set of expressions, oriented to sustain and explain the basic forms or the most frequent use for the interpretation of experimental results. The formulation, mostly based on the initial chapters of the Ph.D. Thesis of G.J. Cuello (Instituto Balseiro, 1996), only considers nuclear scattering of neutrons for extension reasons, but it must be taken into account that the experiments designed for the study of the magnetic properties of materials currently play a rol of importance equal to those

  17. Decoherence Free Neutron Interferometry

    Science.gov (United States)

    Pushin, Dmitry A.; Cory, David G.; Huber, Michael G.; Abutaleb, Mohamed; Arif, Muhammad; Clark, Charles W.

    2011-03-01

    A neutron interferometer (NI) is a unique example of the macroscopic quantum coherence and has been used to test fundamental principles of quantum mechanics. In practice, neutron interferometers are not widely used because of their extreme sensitivity to environmental noise which is in part due to the slow velocity (relative to light) of the neutron. We show that a neutron interferometer design can benefit from concepts of quantum information processing. We have machined a Decoherence Free (DF) neutron interferometer designed using a quantum error correction code, and have shown it to be much less sensitive to mechanical vibrations than is the standard Mach-Zehnder (MZ) interferometer. Both the MZ and DF geometries are incorporated in one crystal, which allows direct comparisons to be made. We believe that our results and related quantum information approaches, such as ``the power of one qubit,''will enable a new series of compact neutron interferometers that can be tailored to specific applications in soft condensed matter and spintronics. D. A. Pushin, M. Arif, and D. G. Cory, Phys. Rev. A (http://pra.aps.org/abstract/PRA/v79/i5/e053635) 79, 053635 (2009)

  18. Biology with neutron radiation

    International Nuclear Information System (INIS)

    Zaccai, Giuseppe

    1993-01-01

    Neutron diffraction, elastic and inelastic neutron scattering experiments provide important information on the structure, interactions and dynamics of biological molecules. This arises from the unique properties of the neutron and of its interaction with matter. Coherent and incoherent neutron scattering amplitudes and cross-sections are very different for H and 2 H (deuterium). Deuterium labelling by chemical or biochemical methods and H 2 O: 2 H 2 O exchange is the basis of high resolution crystallography experiments to locate functionally important H-atoms in protein molecules. It is also very important in low resolution crystallography and small angle scattering experiments to solve large complex structures, such as protein-nucleic acid complexes or biological membrane systems, by using contrast variation techniques. The energies of neutrons with a wavelength of the order of 1 - 10 A are similar to thermal energies and inelastic neutron scattering experiments have been done with different energy resolutions (≥∼ 1 μeV) to characterise the functional dynamics of proteins in solution and in membranes. (author)

  19. Neutron scattering in Australia

    International Nuclear Information System (INIS)

    Knott, R.B.

    1994-01-01

    Neutron scattering techniques have been part of the Australian scientific research community for the past three decades. The High Flux Australian Reactor (HIFAR) is a multi-use facility of modest performance that provides the only neutron source in the country suitable for neutron scattering. The limitations of HIFAR have been recognized and recently a Government initiated inquiry sought to evaluate the future needs of a neutron source. In essence, the inquiry suggested that a delay of several years would enable a number of key issues to be resolved, and therefore a more appropriate decision made. In the meantime, use of the present source is being optimized, and where necessary research is being undertaken at major overseas neutron facilities either on a formal or informal basis. Australia has, at present, a formal agreement with the Rutherford Appleton Laboratory (UK) for access to the spallation source ISIS. Various aspects of neutron scattering have been implemented on HIFAR, including investigations of the structure of biological relevant molecules. One aspect of these investigations will be presented. Preliminary results from a study of the interaction of the immunosuppressant drug, cyclosporin-A, with reconstituted membranes suggest that the hydrophobic drug interdigitated with lipid chains

  20. Volume 15. Neutron scattering

    International Nuclear Information System (INIS)

    Kostorz, G.

    1979-01-01

    This volume of the Treatise on Materials Science and Technology shows how neutron scattering methods can be used to obtain important information on materials, by guiding the reader through the principles and describing recent applications. Materials scientists, but also solid state physicists, physical chemists, and metallurgists interested in this field, will find a completely referenced survey of the ''classical topics'' of neutron scattering and a more detailed presentation of methods and techniques that are more specifically related to materials science. After a brief review of the general principles in the first chapter, subsequent chapters concentrate on particular methods and problems. The techniques used in neutron crystallography are presented, and selected applications of nuclear and magnetic scattering are discussed. The measurement of phonons, their role in phase transformations, and their behavior in the presence of crystal defects are considered, and quasi-elastic scattering is given detailed treatment. The methods of small-angle scattering and diffuse scattering have been developed to a considerable perfection in recent years and are presented in detail. The structure and dynamics of hydrogen dissolved in metals and the conformation and dynamics of polymers are two outstanding subjects to which neutron scattering has contributed so much in recent years that separate chapters are devoted to covering these fields. Finally, the choice of the appropriate materials is also becoming increasingly crucial in the design and construction of neutron spectrometers. Therefore, the last chapter deals with special materials problems in neutron devices

  1. Neutron imaging plates

    International Nuclear Information System (INIS)

    Niimura, Nobuo

    1995-01-01

    Imaging plates have been used in the field of medical diagnosis since long ago, but their usefulness was verified as the two-dimensional detector for analyzing the X-ray crystalline structure of high bio molecules like protein, and they have contributed to the remarkable progress in this field. The great contribution is due to the excellent features, such as the detection efficiency of about 100%, the positional resolution smaller than 0.2 mm, the dynamic range of five digits, and the area of several hundreds mm square. The neutron imaging plates have not yet obtained the sufficient results. It was planned to construct the neutron diffractometer for biological matters, and to put imaging plate neutron detectors (IP-ND) to practical use as the detector. The research on the development of IP-NDs was carried out, and the IPp-NDs having the performance comparable with that for X-ray were able to be produced. Imaging plates are the integral type two-dimensional radiation detector using photostimulated luminescence matters, and their principle is explained. As to neutron imaging plates, the converter, neutron detection efficiency and the flight of secondary particles in photo-stimulated luminescence matters are described. As for the present state of development of neutron imaging plates, the IP-NDs made for trial, the dynamic range, the positional resolution, the detection efficiency and the kinds of converters, and the application of IP-NDs are reported. (K.I.)

  2. Two-neutron removal reactions for very neutron rich nuclei

    International Nuclear Information System (INIS)

    Riisager, K.; Hansen, P.G.; Anne, R.; Lewitowicz, M.; Arnell, S.E.; Neugart, R.; Richter, A.; Bimbot, R.; Guillemaud-Mueller, D.

    1992-01-01

    The two-neutron removal reactions of beams of 11 Li, 14 Be and 8 He upon Be, Ni and Au targets were studied at 30 MeV/u. The cross-sections and the neutron forward angular distributions were measured; they correlate strongly with the two-neutron separation energy of the projectile. Even though the coverage of the neutron detectors was limited, a rough neutron-neutron distribution could be extracted. A simplified interpretation of the data is presented. (author) 57 refs., 7 figs., 2 tabs

  3. Pulsed neutron generator for use with pulsed neutron activation techniques

    International Nuclear Information System (INIS)

    Rochau, G.E.

    1980-01-01

    A high-output, transportable, pulsed neutron generator has been developed by Sandia National Laboratories for use with Pulsed Neutron Activation (PNA) techniques. The PNA neutron generator generates > 10 10 14 MeV D-T neutrons in a 1.2 millisecond pulse. Each operation of the unit will produce a nominal total neutron output of 1.2 x 10 10 neutrons. The generator has been designed to be easily repaired and modified. The unit requires no additional equipment for operation or measurement of output

  4. Measuring the Neutron Lifetime with Magnetically Trapped Ultracold Neutrons

    Science.gov (United States)

    Mumm, H. P.; Huber, M. G.; Yue, A. T.; Thompson, A. K.; Dewey, M. S.; Huffer, C. R.; Huffman, P. R.; Schelhammer, K. W.; O'Shaughnessy, C.; Coakley, K. J.

    2014-03-01

    We describe an experiment to measure the neutron lifetime using a technique with a set of systematic uncertainties largely different than those of previous measurements. In this approach, ultracold neutrons (UCN) are produced by inelastic scattering of cold (0.89 nm) neutrons in a reservoir of superfluid 4He. These neutrons are then confined using a three-dimensional magnetic trap. As the trapped neutrons beta decay, the energetic electrons produced in the decay generate scintillations in the liquid He; each decay is detectable with nearly 100 % efficiency. The neutron lifetime can be directly determined by measuring the scintillation rate as a function of time.

  5. MAGNETIC NEUTRON SCATTERING

    International Nuclear Information System (INIS)

    ZALIZNYAK, I.A.; LEE, S.H.

    2004-01-01

    Much of our understanding of the atomic-scale magnetic structure and the dynamical properties of solids and liquids was gained from neutron-scattering studies. Elastic and inelastic neutron spectroscopy provided physicists with an unprecedented, detailed access to spin structures, magnetic-excitation spectra, soft-modes and critical dynamics at magnetic-phase transitions, which is unrivaled by other experimental techniques. Because the neutron has no electric charge, it is an ideal weakly interacting and highly penetrating probe of matter's inner structure and dynamics. Unlike techniques using photon electric fields or charged particles (e.g., electrons, muons) that significantly modify the local electronic environment, neutron spectroscopy allows determination of a material's intrinsic, unperturbed physical properties. The method is not sensitive to extraneous charges, electric fields, and the imperfection of surface layers. Because the neutron is a highly penetrating and non-destructive probe, neutron spectroscopy can probe the microscopic properties of bulk materials (not just their surface layers) and study samples embedded in complex environments, such as cryostats, magnets, and pressure cells, which are essential for understanding the physical origins of magnetic phenomena. Neutron scattering is arguably the most powerful and versatile experimental tool for studying the microscopic properties of the magnetic materials. The magnitude of the cross-section of the neutron magnetic scattering is similar to the cross-section of nuclear scattering by short-range nuclear forces, and is large enough to provide measurable scattering by the ordered magnetic structures and electron spin fluctuations. In the half-a-century or so that has passed since neutron beams with sufficient intensity for scattering applications became available with the advent of the nuclear reactors, they have became indispensable tools for studying a variety of important areas of modern science

  6. MAGNETIC NEUTRON SCATTERING

    Energy Technology Data Exchange (ETDEWEB)

    ZALIZNYAK,I.A.; LEE,S.H.

    2004-07-30

    Much of our understanding of the atomic-scale magnetic structure and the dynamical properties of solids and liquids was gained from neutron-scattering studies. Elastic and inelastic neutron spectroscopy provided physicists with an unprecedented, detailed access to spin structures, magnetic-excitation spectra, soft-modes and critical dynamics at magnetic-phase transitions, which is unrivaled by other experimental techniques. Because the neutron has no electric charge, it is an ideal weakly interacting and highly penetrating probe of matter's inner structure and dynamics. Unlike techniques using photon electric fields or charged particles (e.g., electrons, muons) that significantly modify the local electronic environment, neutron spectroscopy allows determination of a material's intrinsic, unperturbed physical properties. The method is not sensitive to extraneous charges, electric fields, and the imperfection of surface layers. Because the neutron is a highly penetrating and non-destructive probe, neutron spectroscopy can probe the microscopic properties of bulk materials (not just their surface layers) and study samples embedded in complex environments, such as cryostats, magnets, and pressure cells, which are essential for understanding the physical origins of magnetic phenomena. Neutron scattering is arguably the most powerful and versatile experimental tool for studying the microscopic properties of the magnetic materials. The magnitude of the cross-section of the neutron magnetic scattering is similar to the cross-section of nuclear scattering by short-range nuclear forces, and is large enough to provide measurable scattering by the ordered magnetic structures and electron spin fluctuations. In the half-a-century or so that has passed since neutron beams with sufficient intensity for scattering applications became available with the advent of the nuclear reactors, they have became indispensable tools for studying a variety of important areas of modern

  7. Radiography with polarised neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Michael L.

    2010-08-20

    In this thesis I present a new technique for the spatially resolved investigation of the magnetic properties of bulk samples. Standard one dimensional neutron depolarisation analysis is combined with neutron radiography to a method we call Neutron Depolarisation Imaging (NDI). The experimental setup which was installed at the neutron radiography beam line ANTARES at FRM II consists of a double crystal monochromator, neutron polariser, spin flipper, polarisation analyser and a position sensitive CCD detector. A comprehensive discussion of the requirements for these components is given and the limitations of the method are shown. The maximum spatial resolution which can be achieved with a neutron radiography setup is determined by the collimation of the neutron beam and the distance between sample and detector. Different types of polarisers have been tested and their advantages and disadvantages are discussed. A double crystal monochromator and a new type of polariser employing polarising neutron supermirrors based on the principle of an optical periscope were developed and tested during this work. Furthermore, NDI measurements on various samples of the weakly ferromagnetic materials Pd{sub 1-x}Ni{sub x} and Ni{sub 3}Al are presented. Neutron depolarisation radiography and tomography measurements were conducted with a spatial resolution as high as 0.3 mm on Pd{sub 1-x}Ni{sub x} and Ni{sub 3}Al samples. The feasibility of NDI experiments under hydrostatic pressures up to 10 kbar was shown on a sample of Ni{sub 3}Al using a modified Cu:Be clamp cell. A decrease of the ordering temperature by 2 K under hydrostatic pressure was determined from the NDI measurements and shows the potential of the method for further high pressure experiments. Additionally a method was developed which in principle allows to obtain the intrinsic dependence of the ordering temperature T{sub C} on the ordered moment Ms from NDI measurements on inhomogeneous samples containing regions with

  8. Radiography with polarised neutrons

    International Nuclear Information System (INIS)

    Schulz, Michael L.

    2010-01-01

    In this thesis I present a new technique for the spatially resolved investigation of the magnetic properties of bulk samples. Standard one dimensional neutron depolarisation analysis is combined with neutron radiography to a method we call Neutron Depolarisation Imaging (NDI). The experimental setup which was installed at the neutron radiography beam line ANTARES at FRM II consists of a double crystal monochromator, neutron polariser, spin flipper, polarisation analyser and a position sensitive CCD detector. A comprehensive discussion of the requirements for these components is given and the limitations of the method are shown. The maximum spatial resolution which can be achieved with a neutron radiography setup is determined by the collimation of the neutron beam and the distance between sample and detector. Different types of polarisers have been tested and their advantages and disadvantages are discussed. A double crystal monochromator and a new type of polariser employing polarising neutron supermirrors based on the principle of an optical periscope were developed and tested during this work. Furthermore, NDI measurements on various samples of the weakly ferromagnetic materials Pd 1-x Ni x and Ni 3 Al are presented. Neutron depolarisation radiography and tomography measurements were conducted with a spatial resolution as high as 0.3 mm on Pd 1-x Ni x and Ni 3 Al samples. The feasibility of NDI experiments under hydrostatic pressures up to 10 kbar was shown on a sample of Ni 3 Al using a modified Cu:Be clamp cell. A decrease of the ordering temperature by 2 K under hydrostatic pressure was determined from the NDI measurements and shows the potential of the method for further high pressure experiments. Additionally a method was developed which in principle allows to obtain the intrinsic dependence of the ordering temperature T C on the ordered moment Ms from NDI measurements on inhomogeneous samples containing regions with different ordering temperatures. This

  9. Euratom Neutron Radiography Working Group

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw

    1986-01-01

    In 1979 a Neutron Radiography Working Group (NRWG) was constituted within Buratom with the participation of all centers within the European Community at which neutron facilities were available. The main purpose of NRWG was to standardize methods and procedures used in neutron radiography of nuclear...... reactor fuel as well as establish standards for radiographic image quality of neutron radiographs. The NRWG meets once a year in each of the neutron radiography centers to review the progress made and draw plans for the future. Besides, ad-hoc sub-groups or. different topics within the field of neutron...

  10. Support for cold neutron utilization

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kye Hong; Han, Young Soo; Choi, Sungmin; Choi, Yong; Kwon, Hoon; Lee, Kwang Hee

    2012-06-15

    - Support for experiments by users of cold neutron scattering instrument - Short-term training of current and potential users of cold neutron scattering instrument for their effective use of the instrument - International collaboration for advanced utilization of cold neutron scattering instruments - Selection and training of qualified instrument scientists for vigorous research endeavors and outstanding achievements in experiments with cold neutron - Research on nano/bio materials using cold neutron scattering instruments - Bulk nano structure measurement using small angle neutron scattering and development of analysis technique.

  11. Fifty years of neutron physics

    International Nuclear Information System (INIS)

    Frank, I.M.

    1982-01-01

    A survey of neutron physics achievements during fifty years of its development beginning from neutron discovery in 1932 has been given. A complex of experimental and theoretical data collected by soviet and foreign laboratories in the nucleus fission physics has been considered retrospectively. Neutron methods of nucleus investigation have been described. Theoretical and eXperimental problems of reactor physics and technique arising during the chain nuclear process investigation have been discussed. Up-to-data problems of neutron physics have been considered in detail. A variety of neutron properties and spheres of neutron physics application have been noted

  12. Support for cold neutron utilization

    International Nuclear Information System (INIS)

    Lee, Kye Hong; Han, Young Soo; Choi, Sungmin; Choi, Yong; Kwon, Hoon; Lee, Kwang Hee

    2012-06-01

    - Support for experiments by users of cold neutron scattering instrument - Short-term training of current and potential users of cold neutron scattering instrument for their effective use of the instrument - International collaboration for advanced utilization of cold neutron scattering instruments - Selection and training of qualified instrument scientists for vigorous research endeavors and outstanding achievements in experiments with cold neutron - Research on nano/bio materials using cold neutron scattering instruments - Bulk nano structure measurement using small angle neutron scattering and development of analysis technique

  13. Neutron radiography, techniques and applications

    International Nuclear Information System (INIS)

    Domanus, J.C.

    1987-10-01

    After describing the principles of the ''in pool'' and ''dry'' installations, techniques used in neutron radiography are reviewed. Use of converter foils with silver halide films for the direct and transfer methods is described. Advantages of the use of nitrocellulose film for radiographying radioactive objects are discussed. Dynamic imaging is shortly reviewed. Standardization in the field of neutron radiography (ASTM and Euratom Neutron Radiography Working Group) is described. The paper reviews main fields of use of neutron radiography. Possibilities of use of neutron radiography at research reactors in various scientific, industrial and other fields are mentioned. Examples are given of application of neutron radiography in industry and the nuclear field. (author)

  14. The industrial uses of neutrons

    International Nuclear Information System (INIS)

    Johnson, M.W.

    1994-01-01

    This paper deals with the neutron scattering and radiography techniques that have been used to solve industrial problems. Over the last ten years the application of neutron techniques to industrial problems has grown as neutron techniques have evolved to study ever more complex systems. The problems raised by industry use a wide spectrum of the neutron scattering techniques available, although some techniques are used frequently - especially for studying residual stress, Small Angle Neutron Scattering (SANS) for studying large scale structures, reflectometry and radiography. This paper reviews the techniques involved and illustrates the new problems that are now being solved using accelerator-based pulsed neutron scattering techniques.(author), 26 refs., 8 figs

  15. Neutron-Induced Failures in Semiconductor Devices

    Energy Technology Data Exchange (ETDEWEB)

    Wender, Stephen Arthur [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-04-06

    This slide presentation explores single event effect, environmental neutron flux, system response, the Los Alamos Neutron Science Center (LANSCE) neutron testing facility, examples of SEE measurements, and recent interest in thermal neutrons.

  16. Semiconductor Thermal Neutron Detector

    Directory of Open Access Journals (Sweden)

    Toru Aoki

    2014-02-01

    Full Text Available The  CdTe  and  GaN  detector  with  a  Gd  converter  have  been developed  and  investigated  as  a  neutron  detector  for neutron  imaging.  The  fabricated  Gd/CdTe  detector  with  the  25  mm  thick  Gd  was  designed  on  the  basis  of  simulation results  of  thermal  neutron  detection  efficiency  and  spatial  resolution.  The  Gd/CdTe  detector  shows  the  detection  of neutron  capture  gamma  ray  emission  in  the  155Gd(n,  g156Gd,  157Gd(n,  g158Gd  and  113Cd(n,  g114Cd  reactions  and characteristic X-ray emissions due to conversion-electrons generated inside the Gd film. The observed efficient thermal neutron detection with the Gd/CdTe detector shows its promise in neutron radiography application. Moreover, a BGaN detector has also investigated to separate neutron signal from gamma-ray clearly. 

  17. Neutrons for materials science

    International Nuclear Information System (INIS)

    Windsor, C.G.; Allen, A.J.; Hutchings, M.T.; Sayers, C.M.; Sinclair, R.N.; Schofield, P.; Wright, C.J.

    1985-01-01

    The discussion will be limited to applied materials research performed on a customer/contractor basis. The information obtained using neutrons must therefore compete both scientifically and financially with information obtained using other techniques, particular electron microscopy, X-ray, NMR, infra-red and Raman spectroscopy. It will be argued that the unique nature of the information gained from neutrons often outweighs the undoubted difficulties of access to neutron beams. Small-angle scattering has emerged as the neutron technique of widest application in applied materials research. The penetration of neutron beams through containment vessels, as well as through the sample, allows the measurement of in situ time-dependent experiments within a furnace, cryostat, pressure vessel or chemical reactor vessel. Examples will be given of small-angle scattering projects from the nuclear metallurgy, coal, oil, cement, detergent and plastics industries. High-resolution powder diffraction is another technique with wide applications. Structural studies are possible on increasingly complex phases. The structure and volume fraction of minority phase can be measured at levels appreciably below that possible by X-ray diffraction. A rapidly growing field at present is the measurement of internal strains through the small shifts in lattice spacing. Neutron diffraction is unique in being able to measure the full strain tensor from a specified volume within a bulk specimen. Inelastic scattering measurements exploit the unique property of neutrons to measure the orientations of vibrating molecules. Examples will be chosen from the field of catalysis where inelastic spectroscopy has revealed the nature of the bonding of hydrocarbon molecules. (author)

  18. Study of neutron fields around an intense neutron generator.

    Science.gov (United States)

    Kicka, L; Machrafi, R; Miller, A

    2017-12-01

    Neutron fields in the vicinity of the newly built neutron facility, at the University of Ontario Institute of Technology (UOIT), have been investigated in a series of Monte Carlo simulations and measurements. The facility hosts a P-385 neutron generator based on a deuterium-deuterium fusion reaction. The neutron fluence at different locations around the neutron generator facility has been simulated using MCNPX 2.7E Monte Carlo particle transport program. To characterize neutron fields, three neutron sources were modeled with distributions corresponding to different incident deuteron energies of 90kV, 110kV, and 130kV. Measurements have been carried out to determine the dose rate at locations adjacent to the generator using bubble detectors (BDs). The neutron intensity was evaluated and the total dose rates corresponding to different applied acceleration potentials were estimated at various locations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Development of highly effective neutron shields and neutron absorbing materials

    International Nuclear Information System (INIS)

    Tsuda, K.; Matsuda, F.; Taniuchi, H.; Yuhara, T.; Iida, T.

    1993-01-01

    A wide range of materials, including polymers and hydrogen-occluded alloys that might be usable as the neutron shielding material were examined. And a wide range of materials, including aluminum alloys that might be usable as the neutron-absorbing material were examined. After screening, the candidate material was determined on the basis of evaluation regarding its adaptabilities as a high-performance neutron-shielding and neutron-absorbing material. This candidate material was manufactured for trial, after which material properties tests, neutron-shielding tests and neutron-absorbing tests were carried out on it. The specifications of this material were thus determined. This research has resulted in materials of good performance; a neutron-shielding material based on ethylene propylene rubber and titanium hydride, and a neutron-absorbing material based on aluminum and titanium hydride. (author)

  20. Compact DD generator based in vivo neutron activation analysis (IVNAA) system to determine sodium concentrations in human bone.

    Science.gov (United States)

    Coyne, Mychaela Dawn; Neumann, Colby R; Zhang, Xinxin; Byrne, Patrick; Liu, Yingzi; Weaver, Connie M; Nie, Linda Huiling

    2018-04-16

    This study presents the development of a non-invasive method for monitoring Na in human bone. Many diseases, such as hypertension and osteoporosis, are closely associated with sodium (Na) retention in the human body. Na retention is generally evaluated by calculating the difference between dietary intake and excretion. There is currently no method to directly quantify Na retained in the body. Bone is a storage for many elements, including Na, which renders bone Na an ideal biomarker to study Na metabolism and retention. Approach: A customized compact deuterium-deuterium (DD) neutron generator was used to produce neutrons for in vivo neutron activation analysis (IVNAA), with a moderator/ reflector/ shielding assembly optimized for human hand irradiation in order to maximize the thermal neutron flux inside the irradiation cave and to limit radiation exposure to the hand and the whole body. Main Results: The experimental results show that the system is able to detect sodium levels in the bone as low as 12 g Na/g dry bone with an effective dose to the body of about 27 μSv. The simulation results agree with the numbers estimated from the experiment. Significance: This is expected to be a feasible method for measuring the change of Na in bone. The low detection limit indicates this will be a useful system to study the association between Na retention and related diseases. © 2018 Institute of Physics and Engineering in Medicine.

  1. A utilização da difração de neutrões na determinação do perfil de tensões residuais em revestimentos por soldadura The use of neutron diffraction for the determination of the in-depth residual stresses profile in weld coatings

    Directory of Open Access Journals (Sweden)

    Maria José Marques

    2013-06-01

    Full Text Available A técnica de difração de neutrões é usada neste artigo para estudar amostras ferríticas, revestidas comaços inoxidáveisausteníticos através de soldadura por arco submerso. Este procedimento é frequentemente usado no fabrico de equipamentos de processo para as indústrias química e nuclear, por facilidade de execução e razões económicas. A principal desvantagem deste processo de revestimento é a fissuração que frequentemente ocorre na interface material base/soldadura, potenciada pela presença de tensões residuais resultantes da operação de soldadura, a qual pode ser minimizada com a realização de tratamentos térmicos de relaxação de tensões. As amostras foram produzidas a partir de placas em aço ao carbono, tendo uma das superfícies sido revestida com dois tipos de aço inoxidável. Para a primeira camada foi usado um elétrodo EN 12072 - S 23 12 2 L e para a segunda e a terceira camadas foi usado um elétrodo EN 12072 - S 19 12 3 L. Após a soldadura, as amostras foram submetidas a um tratamento térmico de relaxação de tensões, durante 1 hora, à temperatura de 620ºC. Os perfis de tensões residuais obtidos por difração de neutrões evidenciam a relaxação de tensões residuais após o tratamento térmico realizado. A técnica de difração de neutrões revelou-se muito adequada na avaliação de tensões residuais neste tipo de ligações.The neutron diffraction is a non-destructive technique, particularly suitable for the analysis of residual stress fields in welds. The technique is used in this article to study ferritic samples, coated by submerged arc welding using stainless steel filler metals. This procedure is often used for manufacturing process equipment for chemical and nuclear industries, for ease of implementation and economic reasons. The main disadvantage of that processes is the cracking phenomenon that often occurs at the interface between the base material and coatings, which can be

  2. Introduction to Neutron Coincidence Counter Design Based on Boron-10

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.

    2012-01-22

    The Department of Energy Office of Nonproliferation Policy (NA-241) is supporting the project 'Coincidence Counting With Boron-Based Alternative Neutron Detection Technology' at Pacific Northwest National Laboratory (PNNL) for development of an alternative neutron coincidence counter. The goal of this project is ultimately to design, build and demonstrate a boron-lined proportional tube based alternative system in the configuration of a coincidence counter. This report, providing background information for this project, is the deliverable under Task 1 of the project.

  3. Influence of the neutron transport tube on neutron resonance densitometry

    Directory of Open Access Journals (Sweden)

    Kitatani Fumito

    2017-01-01

    Full Text Available Neutron Resonance Densitometry (NRD is a non-destructive assay technique of nuclear materials in particle-like debris that contains various materials. An aim of NRD is to quantify nuclear materials in a melting fuel of Fukusima Daiichi plant, spent nuclear fuel and annihilation disposal fuel etc. NRD consists of two techniques of Neutron Resonance Transmission Analysis (NRTA and Neutron Resonance Capture Analysis (NRCA or Prompt Gamma-ray Analysis (PGA. A density of nuclear material isotopes is decided with NRTA. The materials absorbing a neutron in a wide energy range such as boron in a sample are identified by NRCA/PGA. The information of NRCA/PGA is used in NRTA analysis to quantify nuclear material isotopes. A neutron time of flight (TOF method is used in NRD measurements. A facility, consisting of a neutron source, a neutron flight path, and a detector is required. A short flight path and a strong neutron source are needed to downsize such a facility and put NRD into practical use. A neutron transport tube covers a flight path to prevent noises. In order to investigate the effect of neutron transport tube and pulse width of a neutron source, we carried out NRTA experiments with a 2-m short neutron transport tube constructed at Kyoto University Research Reactor Institute - Linear Accelerator (KURRI-LINAC, and impacts of shield of neutron transport tube and influence of pulse width of a neutron source were examined. A shield of the neutron transport tube reduced a background and had a good influence on the measurement. The resonance dips of 183W at 27 eV was successfully observed with a pulse width of a neutron source less than 2 μs.

  4. Influence of the neutron transport tube on neutron resonance densitometry

    Science.gov (United States)

    Kitatani, Fumito; Tsuchiya, Harufumi; Koizumi, Mitsuo; Takamine, Jun; Hori, Junichi; Sano, Tadafumi

    2017-09-01

    Neutron Resonance Densitometry (NRD) is a non-destructive assay technique of nuclear materials in particle-like debris that contains various materials. An aim of NRD is to quantify nuclear materials in a melting fuel of Fukusima Daiichi plant, spent nuclear fuel and annihilation disposal fuel etc. NRD consists of two techniques of Neutron Resonance Transmission Analysis (NRTA) and Neutron Resonance Capture Analysis (NRCA) or Prompt Gamma-ray Analysis (PGA). A density of nuclear material isotopes is decided with NRTA. The materials absorbing a neutron in a wide energy range such as boron in a sample are identified by NRCA/PGA. The information of NRCA/PGA is used in NRTA analysis to quantify nuclear material isotopes. A neutron time of flight (TOF) method is used in NRD measurements. A facility, consisting of a neutron source, a neutron flight path, and a detector is required. A short flight path and a strong neutron source are needed to downsize such a facility and put NRD into practical use. A neutron transport tube covers a flight path to prevent noises. In order to investigate the effect of neutron transport tube and pulse width of a neutron source, we carried out NRTA experiments with a 2-m short neutron transport tube constructed at Kyoto University Research Reactor Institute - Linear Accelerator (KURRI-LINAC), and impacts of shield of neutron transport tube and influence of pulse width of a neutron source were examined. A shield of the neutron transport tube reduced a background and had a good influence on the measurement. The resonance dips of 183W at 27 eV was successfully observed with a pulse width of a neutron source less than 2 μs.

  5. Magnetic investigations using neutron diffraction and neutron depolarization

    International Nuclear Information System (INIS)

    Yusuf, S.M.

    2015-01-01

    In this article, the basic principles of neutron diffraction and neutron depolarization are presented along with the results of some important magnetic materials. In particular, the recent results of the rare earth based high magnetocaloric effect materials, semi-Heusler spintronics alloys, molecular magnets, layered spin system, and core-shell type magnetic nanoparticles have been described. The usefulness of the neutron diffraction and neutron depolarization techniques to understand structural and magnetic properties is brought out. (author)

  6. Present-day neutron diffraction at pulsed neutron sources

    International Nuclear Information System (INIS)

    Balagurov, A.M.

    1992-01-01

    The current status of neutron-diffraction experiments at pulsed neutron sources is described. The general problems in time-of-flight neutron-diffraction studies are discussed. High-resolution experiments on polycrystalline materials, structure analysis, and special experiments using single crystals are discussed, along with studies of transient processes of short duration. Special attention is paid to recent topics: very high-resolution diffractometry, neutron Fourier diffractometers, and real-time studies. 81 refs., 20 figs., 6 tabs

  7. Imaging with cold neutrons

    International Nuclear Information System (INIS)

    Lehmann, E.H.; Kaestner, A.; Josic, L.; Hartmann, S.; Mannes, D.

    2011-01-01

    Neutrons for imaging purposes are provided mainly from thermal beam lines at suitable facilities around the world. The access to cold neutrons is presently limited to very few places only. However, many challenging options for imaging with cold neutrons have been found out, given by the interaction behavior of the observed materials with neutrons in the cold energy range (3-10 A). For absorbing materials, the interaction probability increases proportionally with the wavelength with the consequence of more contrast but less transmission with cold neutrons. Many materials are predominantly scattering neutrons, in particular most of crystalline structural materials. In these cases, cold neutrons play an important role by covering the energy range of the most important Bragg edges given by the lattice planes of the crystallites. This particular behavior can be used for at least two important aspects-choosing the right energy of the initial beam enables to have a material more or less transparent, and a direct macroscopic visualization of the crystalline structure and its change in a manufacturing process. Since 2006, PSI operates its second beam line for neutron imaging, where cold neutrons are provided from a liquid deuterium cold source (operated at 25 K). It has been designed to cover the most current aspects in neutron imaging research with the help of high flexibility. This has been done with changeable inlet apertures, a turbine based velocity selector, two beam positions and variable detector systems, satisfying the demands of the individual investigation. The most important detection system was found to be a micro-tomography system that enables studies in the presently best spatial resolution. In this case, the high contrast from the sample interaction process and the high detection probability for the cold neutrons combines in an ideal combination for the best possible performance. Recently, it was found out that the energy selective studies might become a

  8. Imaging with cold neutrons

    Science.gov (United States)

    Lehmann, E. H.; Kaestner, A.; Josic, L.; Hartmann, S.; Mannes, D.

    2011-09-01

    Neutrons for imaging purposes are provided mainly from thermal beam lines at suitable facilities around the world. The access to cold neutrons is presently limited to very few places only. However, many challenging options for imaging with cold neutrons have been found out, given by the interaction behavior of the observed materials with neutrons in the cold energy range (3-10 Å). For absorbing materials, the interaction probability increases proportionally with the wavelength with the consequence of more contrast but less transmission with cold neutrons. Many materials are predominantly scattering neutrons, in particular most of crystalline structural materials. In these cases, cold neutrons play an important role by covering the energy range of the most important Bragg edges given by the lattice planes of the crystallites. This particular behavior can be used for at least two important aspects—choosing the right energy of the initial beam enables to have a material more or less transparent, and a direct macroscopic visualization of the crystalline structure and its change in a manufacturing process. Since 2006, PSI operates its second beam line for neutron imaging, where cold neutrons are provided from a liquid deuterium cold source (operated at 25 K). It has been designed to cover the most current aspects in neutron imaging research with the help of high flexibility. This has been done with changeable inlet apertures, a turbine based velocity selector, two beam positions and variable detector systems, satisfying the demands of the individual investigation. The most important detection system was found to be a micro-tomography system that enables studies in the presently best spatial resolution. In this case, the high contrast from the sample interaction process and the high detection probability for the cold neutrons combines in an ideal combination for the best possible performance. Recently, it was found out that the energy selective studies might become a

  9. Activation analysis utilizing byproduct neutrons of cyclotron internal target runs

    International Nuclear Information System (INIS)

    Koh, K.; Finn, R.; Smith, P.; Tavano, E.; Dwyer, J.; Sheh, H.

    1985-01-01

    The neutron flux generated by the CS-30 cyclotron at Mt Sinai Medical Center during routine internal target runs was characterized by employing various elements as neutron monitors. The characteristic (p,xn) nuclear reactions from internal targets bombarded by 26.5 Mev protons and the cyclotron inner wall bombarded by stray protons produce a neutron flux of approximately 2 x 10 9 cm -2 s -1 at energies up to 22 MeV at a point immediately outside the cyclotron vacuum chamber. Samples exposed to neutron fluences up to 5 x 10 14 cm -2 were analyzed with a Ge(Li) detector. Although the detection limits are relatively high (i.e., Au-0.2 μg; In-1 μg; Na-50 μg), this mode of neutron activation analysis is ancillary to other irradiations and allows a large number of samples to be monitored. This approach may provide an alternative to a neutron generator for research activation applications. (orig.)

  10. Method to determine the strength of a neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H.R.; Manzanares A, E.; Hernandez D, V.M.; Chacon R, A.; Mercado, G.A. [UAZ, A.P. 336, 98000 Zacatecas (Mexico); Gallego, E.; Lorente, A. [Depto. Ingenieria Nuclear, Universidad Politecnica de Madrid, (Spain)

    2006-07-01

    The use of a gamma-ray spectrometer with a 3 {phi} x 3 NaI(Tl) detector, with a moderator sphere has been studied in the aim to measure the neutron fluence rate and to determine the source strength. Moderators with a large amount of hydrogen are able to slowdown and thermalize neutrons; once thermalized there is a probability that thermal neutron to be captured by hydrogen producing 2.22 MeV prompt gamma-ray. The pulse-height spectrum collected in a multicharmel analyzer shows a photopeak around 2.22 MeV whose net area is proportional to total neutron fluence rate and to the neutron source strength. The characteristics of this system were determined by a Monte Carlo study using the MCNP 4C code, where a detailed model of the Nal(Tl) was utilized. As moderators 3, 5, and 10 inches-diameter spheres where utilized and the response was calculated for monoenergetic and isotopic neutrons sources. (Author)

  11. In vivo neutron activation facility at Brookhaven National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Ma, R.; Yasumura, Seiichi; Dilmanian, F.A.

    1997-11-01

    Seven important body elements, C, N, Ca, P, K, Na, and Cl, can be measured with great precision and accuracy in the in vivo neutron activation facilities at Brookhaven National Laboratory. The facilities include the delayed-gamma neutron activation, the prompt-gamma neutron activation, and the inelastic neutron scattering systems. In conjunction with measurements of total body water by the tritiated-water dilution method several body compartments can be defined from the contents of these elements, also with high precision. In particular, body fat mass is derived from total body carbon together with total body calcium and nitrogen; body protein mass is derived from total body nitrogen; extracellular fluid volume is derived from total body sodium and chlorine; lean body mass and body cell mass are derived from total body potassium; and, skeletal mass is derived from total body calcium. Thus, we suggest that neutron activation analysis may be valuable for calibrating some of the instruments routinely used in clinical studies of body composition. The instruments that would benefit from absolute calibration against neutron activation analysis are bioelectric impedance analysis, infrared interactance, transmission ultrasound, and dual energy x-ray/photon absorptiometry.

  12. Determinação da composição mineral de subprodutos agroindustriais utilizados na alimentação animal, pela técnica de ativação neutrônica Determination of the mineral composition in agroindustrial by-products used in animal nutrition, by neutron activation analysis

    Directory of Open Access Journals (Sweden)

    José Cleto da Silva Filho

    1999-02-01

    Full Text Available O presente trabalho teve como objetivo analisar alguns subprodutos agroindustriais utilizados na alimentação animal e identificar os principais minerais presentes. Amostras de farelos de algodão, arroz, canola, soja e trigo; farinhas de peixe, carne e penas + vísceras; cascas de algodão, arroz, laranja; bagaços de tomate e de laranja foram coletadas em diferentes locais de produção. O método analítico empregado foi a análise por ativação com nêutrons seguida de espectrometria gama. Os níveis de minerais encontrados em todas as amostras, inclusive aqueles considerados tóxicos, tais como As, Cd e Hg, não excederam os limites máximos permitidos em dietas para animais domésticos. Os valores obtidos foram comparados com os comumente encontrados em forragens.This study aimed to analyze some agroindustrial by-products used to feed animals in order to identify the presence of the main minerals. Samples of cotton seed meal, rice, canola, soybean and wheat; fish meal, feather meal, meat meal, feather plus viscera meal; rinds of cotton, rice, orange; citrus pulp and tomato residue were collected in different sites of production of the by-products. The method of analysis used was the neutron activation followed by gamma ray spectrometry. The levels of minerals found in all samples were compared with the levels commonly found in forages. The mineral concentration, even those of the toxic elements, as As, Cd and Hg, was at low level and did not exceed the maximum tolerable levels for domestic animals.

  13. Storing of free neutrons

    International Nuclear Information System (INIS)

    Trinks, U.

    1978-12-01

    The applied method makes use of the interaction between the magnetic moment μ vector of the neutron and a magnetic field B vector. By means of superconducting magnets there can easily be achieved potential walls of μ B approximately 2 x 10 -7 eV. The principle of magnetic storing was first used for the storage ring NESTOR and showed immediate success: the stored neutrons decreased exponentially with a time constant tau = (907 +- 70) sec corresponding to the natural lifetime of the neutrons within the statistical errors. This means that there occurred no measurable additional losses (e.g. by resonance excitation) Neutrons therefore could be observed in the storage ring during about 5 half-lives (in principle of course longer, too). The orbit dynamics for neutrons in the storage ring is smilar to that in circular accelerators for charged particles. It is so well understood that the problem of the storage ring for uncharged particles (with magnetic moment) may be considered to e solved. (orig./HSI) [de

  14. Neutron source multiplication method

    International Nuclear Information System (INIS)

    Clayton, E.D.

    1985-01-01

    Extensive use has been made of neutron source multiplication in thousands of measurements of critical masses and configurations and in subcritical neutron-multiplication measurements in situ that provide data for criticality prevention and control in nuclear materials operations. There is continuing interest in developing reliable methods for monitoring the reactivity, or k/sub eff/, of plant operations, but the required measurements are difficult to carry out and interpret on the far subcritical configurations usually encountered. The relationship between neutron multiplication and reactivity is briefly discussed and data presented to illustrate problems associated with the absolute measurement of neutron multiplication and reactivity in subcritical systems. A number of curves of inverse multiplication have been selected from a variety of experiments showing variations observed in multiplication during the course of critical and subcritical experiments where different methods of reactivity addition were used, with different neutron source detector position locations. Concern is raised regarding the meaning and interpretation of k/sub eff/ as might be measured in a far subcritical system because of the modal effects and spectrum differences that exist between the subcritical and critical systems. Because of this, the calculation of k/sub eff/ identical with unity for the critical assembly, although necessary, may not be sufficient to assure safety margins in calculations pertaining to far subcritical systems. Further study is needed on the interpretation and meaning of k/sub eff/ in the far subcritical system

  15. Neutrons and art

    International Nuclear Information System (INIS)

    Panczyk, E.; Walis, L.

    2004-01-01

    Following modern trends in art objects connoisseurship, through examination of the structure of art objects supports traditional studies conducted by art historians based on composition, iconographic and stylistic comparisons. It must be emphasized that complete technological examinations are carried out by means of comprehensive physical and chemical studies. Among various methods used for the examination of art objects, methods which apply neutrons such as instrumental neutron activation analysis (INAA), prompt gamma activation analysis (PGAA) and neutron-induced autoradiography are crucial due to their high sensitivity, reproducibility and capability of simultaneous determination of several tens of elements. Systematic studies on art objects using instrumental neutron activation analysis and neutron autoradiography have been carried out in the institute of Nuclear Chemistry and Technology. It was possible to accumulate a number of essential data on the concentration of trace elements particularly in chalk grounds and pigments (such as lead white, lead-tin yellow, smalt), Chinese porcelain, Thai ceramics, silver denarius, jewellery made of copper alloys, as well as in the clay fillings of Egyptian mummies. The above mentioned examination of art objects prior to their conservation helps to determine precisely the materials used in the process of creating art objects, as well as to identify the appropriate place of origin of particular materials. (author)

  16. Neutron small angle scattering

    International Nuclear Information System (INIS)

    Ibel, K.

    1975-01-01

    The neutron small-angle scattering system at the High-Flux Reactor in Grenoble consists of three major parts: the supply of cold neutrons via bent neutron guides; the small angle camera D11; and the data handling facilities. The camera D11 has an overall length of 80 m. The effective length of the camera is variable. The length of the collimator before the fixed sample position can be reduced by movable neutron guides; the secondary flight path of 40 m full length contains detector sites in various positions. Thus, a large domain of momentum transfers can be exploited. Scattering angles between 5.10 -4 and 0.5 rad and neutron wavelengths from 0.2 to 2.0 nm are available with the same instrument and the same relative resolution. A large-area position-sensitive detector is used which allows simultaneous recording of intensities scattered into different angles; it is a multiwire proportional chamber. 3808 elements of 1 cm 2 are arranged in a two-dimensional matrix. Future development comprises an increase of the limit in the count rate due to the electronic interface between the detector and on-line computer, actually at 5.10 4 per sec. by one order of magnitude

  17. On neutron topograph

    International Nuclear Information System (INIS)

    Tomimitsu, Hiroshi

    1974-01-01

    Results of neutron topography on a Ge single crystal are described. The neutron source was a horizontal experimental hole of JRR-3 of Japan Atomic Energy Research Institute. Neutrons of the wave length of 1 -- 2A were selected for the experiment. The sample was a Ge crystal containing a small amount of phosphorus, which was made as a transistor. Press was applied at 75 kg/cm 2 of pressure in direction at 850 0 C. The sample satisfied kinematical condition. As for a converter system, a Rh plate of 1/100 inch thick, an X-ray film, and a Gd foil of 1/500 inch thick were arranged. The resolving power of the system was about 40 μ. Patterns of overall contrast variation due to hot-press are shown in figures. Distortion field arose along the direction of press unevenly. Difference of image quality due to wave length was investigated. Topographs with longer wave length shown better contrast and better resolving power. Collimation of neutron beam seems to be necessary. Various techniques were tried to obtain stereoscopic view of distortion field. Uneven distribution of distortion was confirmed. The same results were also obtained from X-ray topography. The kinematical interpretation of taken topographs was possible. Evaluation of the resolving power of neutron topography is described in Appendix. (Kato, T.)

  18. Neutron shielding material

    International Nuclear Information System (INIS)

    Nodaka, M.; Iida, T.; Taniuchi, H.; Yosimura, K.; Nagahama, H.

    1993-01-01

    From among the neutron shielding materials of the 'kobesh' series developed by Kobe Steel, Ltd. for transport and storage packagings, silicon rubber base type material has been tested for several items with a view to practical application and official authorization, and in order to determine its adaptability to actual vessels. Silicon rubber base type 'kobesh SR-T01' is a material in which, from among the silicone rubber based neutron shielding materials, the hydrogen content is highest and the boron content is most optimized. Its neutron shielding capability has been already described in the previous report (Taniuchi, 1986). The following tests were carried out to determine suitability for practical application; 1) Long-term thermal stability test 2) Pouring test on an actual-scale model 3) Fire test The experimental results showed that the silicone rubber based neutron shielding material has good neutron shielding capability and high long-term fire resistance, and that it can be applied to the advanced transport packaging. (author)

  19. Texture and neutron diffraction

    International Nuclear Information System (INIS)

    Szpunar, J.

    1976-01-01

    The neutron diffraction method has only recently become a tool for studying the structure of polycrystalline materials. There are some fields such as texture studies where this method offers several advantages over other more common methods. Texture is the main subject of the review. The current status of the theory or deformation and recrystallization texture is discussed briefly. Texture is then described with the aid of the ODF function. Finally, applications of the neutron diffraction method are discussed using several examples of textures measured in metals and in non-metallic materials. Other, less known applications of neutron diffraction are also given, e.g. in stress measurements. The neutron diffraction method is extremely useful for studying the texture of coarse-grained materials. This method provides information on the average texture in a large volume. This enables one to measure texture in the same specimen in which anisotropy of the physical roperties has been measured. Selected examples are provided in which correlations between elastic, plastic and magnetic properties of polycrystalline materials and their texture are pointed out. Texture was measured in all these cases using the neutron diffraction method. (author)

  20. The Advanced Neutron Source

    International Nuclear Information System (INIS)

    Peretz, F.J.

    1990-01-01

    The Advanced Neutron Source (ANS) is to be a multipurpose neutron research center, constructed around a high-flux reactor now being designed at the Oak Ridge National Laboratory (ORNL). Its primary purpose is to place the United States in the forefront of neutron scattering in the twenty-first century. Other research programs include nuclear and fundamental physics, isotope production, materials irradiation, and analytical chemistry. The ANS will be a unique and invaluable research tool because of the unprecedented neutron flux available from the high-intensity research reactor. But this reactor would be ineffective without world-class research facilities that allow the fullest utilization of the available neutrons. And, in turn, those research facilities will not produce new and exciting science without a broad population of users from all parts of the nation and the world, placed in a stimulating environment in which experiments can be effectively conducted and in which scientific exchange is encouraged. This paper discusses the measures being taken to ensure that the design of the ANS focuses not only on the reactor, but on providing the experiment and user support facilities needed to allow its effective use

  1. Fast neutron dosimetry

    International Nuclear Information System (INIS)

    DeLuca, P.M. Jr.; Pearson, D.W.

    1991-01-01

    During 1988--1990 the magnetic resonance dosimetry project was completed, as were the 250 MeV proton shielding measurements. The first cellular experiment using human cells in vitro at the 1 GeV electron storage ring was also accomplished. More detail may be found in DOE Report number-sign DOE/EV/60417-002 and the open literature cited in the individual progress subsections. We report Kinetic Energy Released in Matter (KERMA), factor measurements in several elements of critical importance to neutron radiation therapy and radiation protection for space habitation and exploration for neutron energies below 30 MeV. The results of this effort provide the only direct measurements of the oxygen and magnesium kerma factors above 20 MeV neutron energy, and the only measurements of the iron kerma factor above 15 MeV. They provide data of immediate relevance to neutron radiotherapy and impose strict criteria for normalizing and testing nuclear models used to calculate kerma factors at higher neutron energies

  2. Direct Observation of Neutron Scattering in BC408 Scintillator for Comparison with SImulation

    Science.gov (United States)

    Rogers, W. F.; Boone, J. E.; Wantz, A.; Frank, N.; Kuchera, A. N.; Mosby, S.; Thoennessen, M.; MoNA Collaboration

    2017-09-01

    Monte Carlo simulation provides an important tool for the interpretation of neutron scattering data in the Modular Neutron Array (MoNA) and the Large multi-Institutional Scintillator Array (LISA), each located at the NSCL facility at MSU and consisting of 144 stacked 2-m long organic plastic scintillator bar detectors. Energy and trajectory for unbound state decay neutrons are determined by time of flight and location of first light produced in the array. While most neutrons scattering elastically from protons and inelastically from C nuclei produce light above detector threshold, those scattered elastically from C remain below threshold (``dark scatter''), altering neutron trajectories, thus decreasing energy and momentum resolution. To test the accuracy of our Geant4/MENATE_R simulations, we observed neutrons scattering from 16 MoNA bars arranged in two stack geometries at the LANSCE facility at Los Alamos National Laboratory. Spallation neutrons ranging in energy from 0.5 to 800 MeV emerged from a 3 mm collimator in the 90m shed on WNR flight path 4FP15L and struck the array along a well defined path. Results for neutron hit multiplicity, scattering dynamics, and dark scatter redirection are compared with simulation. Work supported by NSF Grant PHY-1744043.

  3. Probing neutron star physics using accreting neutron stars

    NARCIS (Netherlands)

    Patruno, A.

    2010-01-01

    We give an obervational overview of the accreting neutron stars systems as probes of neutron star physics. In particular we focus on the results obtained from the periodic timing of accreting millisecond X-ray pulsars in outburst and from the measurement of X-ray spectra of accreting neutron stars

  4. Neutron imaging and small angle neutron scattering instruments at KUR

    International Nuclear Information System (INIS)

    Saito, Yasushi; Oba, Yojiro; Hino, Masahiro

    2015-01-01

    We review the neutron imaging (NI) and small-angle neutron scattering (SANS) instruments at KUR, Kumatori, Osaka, Japan. There are two NI and one SANS instruments. The both instruments are compact and used flexibly. Some challenging experiments taking advantage of low neutron fluence are described. The feature of KUR is also described briefly. (author)

  5. Investigation of Response of Several Neutron Surveymeters by a DT Neutron Generator

    International Nuclear Information System (INIS)

    Kim, Sang In; Jang, In Su; Kim, Jang Lyul; Lee, Jung IL; Kim, Bong Hwan

    2012-01-01

    Several neutron measuring devices were tested under the neutron fields characterized with two distinct kinds of thermal and fast neutron spectrum. These neutron fields were constructed by the mixing of both thermal neutron fields and fast neutron fields. The thermal neutron field was constructed using by a graphite pile with eight AmBe neutron sources. The fast neutron field of 14 MeV was made by a DT neutron generator. In order to change the fraction of fast neutron fluence rate in each neutron fields, a neutron generator was placed in the thermal neutron field at 50 cm and 150 cm from the reference position. The polyethylene neutron collimator was used to make moderated 14 MeV neutron field. These neutron spectra were measured by using a Bonner sphere system with an LiI scintillator, and dosimetric quantities delivered to neutron surveymeters were determined from these measurement results.

  6. Gadolinium neutron capture therapy

    International Nuclear Information System (INIS)

    Akine, Yasuyuki; Tokita, Nobuhiko; Tokuuye, Koichi; Satoh, Michinao; Churei, Hisahiko

    1993-01-01

    Gadolinium neutron capture therapy makes use of photons and electrons produced by nuclear reactions between gadolinium and lower-energy neutrons which occur within the tumor. The results of our studies have shown that its radiation effect is mostly of low LET and that the electrons are the significant component in the over-all dose. The dose from gadolinium neutron capture reactions does not seem to increase in proportion to the gadolinium concentration, and the Gd-157 concentration of about 100 μg/ml appears most optimal for therapy. Close contact between gadolinium and the cell is not necessarily required for cell inactivation, however, the effect of electrons released from intracellular gadolinium may be significant. Experimental studies on tumor-bearing mice and rabbits have shown that this is a very promising modality though further improvements in gadolinium delivery to tumors are needed. (author)

  7. The neutron discovery

    International Nuclear Information System (INIS)

    Six, J.

    1987-01-01

    The neutron: who had first the idea, who discovered it, who established its main properties. To these apparently simple questions, multiple answers exist. The progressive discovery of the neutron is a marvellous illustration of some characteristics of the scientific research, where the unforeseen may be combined with the expected. This discovery is replaced in the context of the 1930's scientific effervescence that succeeded the revolutionary introduction of quantum mechanics. This book describes the works of Bothe, the Joliot-Curie and Chadwick which led to the neutron in an unexpected way. A historical analysis allows to give a new interpretation on the hypothesis suggested by the Joliot-Curie. Some texts of these days will help the reader to revive this fascinating story [fr

  8. Small angle neutron scattering

    International Nuclear Information System (INIS)

    Dasannacharya, B.A.; Goyal, P.S.

    1997-01-01

    Small angle neutron scattering (SANS) is one of the most popular neutron scattering technique both for the basic research and as a tool in the hands of applied scientist. SANS is used for studying the structure of a material on a length scale of 10 - 1000 A. SANS is a diffraction experiment that involves scattering of a monocromatic beam of neutrons in order to obtain structural information about macromolecules and heterogeneities. This paper will discuss the design of SANS spectrometers with a special emphasis on the instruments which are better suited for medium flux reactors. The design of several different types of SANS spectrometers will be given. The optimization procedures and appropriate modifications to suit the budget and the space will be discussed. As an example, the design of a SANS spectrometer at CIRUS reactor Trombay will be given. (author)

  9. Direction sensitive neutron detector

    Science.gov (United States)

    Ahlen, Steven; Fisher, Peter; Dujmic, Denis; Wellenstein, Hermann F.; Inglis, Andrew

    2017-01-31

    A neutron detector includes a pressure vessel, an electrically conductive field cage assembly within the pressure vessel and an imaging subsystem. A pressurized gas mixture of CF.sub.4, .sup.3He and .sup.4He at respective partial pressures is used. The field cage establishes a relatively large drift region of low field strength, in which ionization electrons generated by neutron-He interactions are directed toward a substantially smaller amplification region of substantially higher field strength in which the ionization electrons undergo avalanche multiplication resulting in scintillation of the CF.sub.4 along scintillation tracks. The imaging system generates two-dimensional images of the scintillation patterns and employs track-finding to identify tracks and deduce the rate and direction of incident neutrons. One or more photo-multiplier tubes record the time-profile of the scintillation tracks permitting the determination of the third coordinate.

  10. Spherical neutron generator

    Science.gov (United States)

    Leung, Ka-Ngo

    2006-11-21

    A spherical neutron generator is formed with a small spherical target and a spherical shell RF-driven plasma ion source surrounding the target. A deuterium (or deuterium and tritium) ion plasma is produced by RF excitation in the plasma ion source using an RF antenna. The plasma generation region is a spherical shell between an outer chamber and an inner extraction electrode. A spherical neutron generating target is at the center of the chamber and is biased negatively with respect to the extraction electrode which contains many holes. Ions passing through the holes in the extraction electrode are focused onto the target which produces neutrons by D-D or D-T reactions.

  11. Corrosion resistant neutron absorbing coatings

    Science.gov (United States)

    Choi, Jor-Shan [El Cerrito, CA; Farmer, Joseph C [Tracy, CA; Lee, Chuck K [Hayward, CA; Walker, Jeffrey [Gaithersburg, MD; Russell, Paige [Las Vegas, NV; Kirkwood, Jon [Saint Leonard, MD; Yang, Nancy [Lafayette, CA; Champagne, Victor [Oxford, PA

    2012-05-29

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  12. Neutron emission anisotropy in fission

    OpenAIRE

    CHIETERA A.; STUTTGE L.; GOENNENWEIN F.; KOPATCH Y.; MUTTERER M.; GUSEVA I.; GAGARSKI A.; CHERNYSHEVA E; DORVAUX O; HAMBSCH Franz-Josef; HANAPPE F.; MEZENTSEVAH Z.; TELEZHNIKOVCH S.

    2015-01-01

    Experimental neutron angular distributions are investigated in the spontaneous fission process of 252Cf. The CORA experiment, presented in this paper, has the aim to study neutron angular correlations in order to elucidate the neutron emission mechanisms in the fission process. The experimental setup is composed by the CODIS fission chamber and the DEMON neutron multidetector. The development of a simulation toolkit based on GEANT4 and ROOT adopted as strategy to investigate the emission of t...

  13. Neutron methods for industrial applications

    International Nuclear Information System (INIS)

    Glazkov, V.; Kvardakov, V.; Podurets, K.; Somenkov, V.; Shilstein, S.

    1999-01-01

    Complete text of publication follows. The results of industrial applications of various neutron methods (coherent and incoherent neutron scattering, absorption and refraction radiography, topography) are discussed. The main directions of the applied neutron program of Kurchatov Institute are the hydrogen detection in industrial materials at trace levels, visualization of defects in single crystal turbine blades, study of composite materials and steels with inhomogeneous magnetic and atomic structure, neutron focusing radiography and tomography. (author)

  14. Din - an indiviual neutron dosemeter

    International Nuclear Information System (INIS)

    Buxerolle, M.

    1987-09-01

    An albedo neutron dosemeter with 6 LiF and 7 Lif thermoluminescent detectors has been developed. A cadmium shield limits the effect of the distance from the body to the dosemeter and the effect of thermal neutrons scattered by the surroundings. The thickness of the cadmium filter has been adjusted so that the response is about the same for thermal neutrons (maxwellian) and epithermal neutrons (1/E spectrum with the energy E [fr

  15. Neutron capture in borehole logging

    International Nuclear Information System (INIS)

    Randall, R.R.

    1981-01-01

    The use is described of a pulsed source of fast neutrons and a radiation detector to measure the thermal neutron population decay rate in a well logging instrument. The macroscopic neutron absorption cross-section is calculated by taking the natural logarithm of the ratio of the detected radiation counts occurring within two measurement intervals of fixed duration and starting at a fixed time after a neutron burst. (U.K.)

  16. Neutron fluxes and spectra of the neutron guide tubes in the upgraded JRR-3

    International Nuclear Information System (INIS)

    Kawabata, Y.; Suzuki, M.; Tsuruno, A.; Onishi, N.

    1992-01-01

    A cold neutron source with two thermal and three cold neutron guide tubes has been installed in the upgraded JRR-3. Neutron fluxes, time-of-flight spectra and the gain of the cold neutron source were measured at the end of the neutron guide tubes. The neutron beam distributions were found by neutron radiography films. (orig.)

  17. POLARIZED NEUTRONS IN RHIC

    Energy Technology Data Exchange (ETDEWEB)

    COURANT,E.D.

    1998-04-27

    There does not appear to be any obvious way to accelerate neutrons, polarized or otherwise, to high energies by themselves. To investigate the behavior of polarized neutrons the authors therefore have to obtain them by accelerating them as components of heavier nuclei, and then sorting out the contribution of the neutrons in the analysis of the reactions produced by the heavy ion beams. The best neutron carriers for this purpose are probably {sup 3}He nuclei and deuterons. A polarized deuteron is primarily a combination of a proton and a neutron with their spins pointing in the same direction; in the {sup 3}He nucleus the spins of the two protons are opposite and the net spin (and magnetic moment) is almost the same as that of a free neutron. Polarized ions other than protons may be accelerated, stored and collided in a ring such as RHIC provided the techniques proposed for polarized proton operation can be adapted (or replaced by other strategies) for these ions. To accelerate polarized particles in a ring, one must make provisions for overcoming the depolarizing resonances that occur at certain energies. These resonances arise when the spin tune (ratio of spin precession frequency to orbit frequency) resonates with a component present in the horizontal field. The horizontal field oscillates with the vertical motion of the particles (due to vertical focusing); its frequency spectrum is dominated by the vertical oscillation frequency and its modulation by the periodic structure of the accelerator ring. In addition, the magnet imperfections that distort the closed orbit vertically contain all integral Fourier harmonics of the orbit frequency.

  18. Introductory theory of neutron scattering

    International Nuclear Information System (INIS)

    Gunn, J.M.F.

    1986-12-01

    The paper comprises a set of six lecture notes which were delivered to the summer school on 'Neutron Scattering at a pulsed source', Rutherford Laboratory, United Kingdom, 1986. The lectures concern the physical principles of neutron scattering. The topics of the lectures include: diffraction, incoherent inelastic scattering, connection with the Schroedinger equation, magnetic scattering, coherent inelastic scattering, and surfaces and neutron optics. (UK)

  19. Neutronic measurements of radioactive waste

    International Nuclear Information System (INIS)

    Perot, B.

    1997-01-01

    This document presents the general matters involved in the radioactive waste management and the different non destructive assays of radioactivity. The neutronic measurements used in the characterization of waste drums containing emitters are described with more details, especially the active neutronic interrogation assays with prompt or delayed neutron detection: physical principle, signal processing and evaluation of the detection limit. (author)

  20. Neutron absorbing article

    International Nuclear Information System (INIS)

    Naum, R.G.; Owens, D.P.; Dooker, G.I.

    1981-01-01

    A neutron-absorbing article suitable for use in spent fuel racks is described. It comprises boron carbide particles, diluent particles, and a phenolic polymer cured to a continuous matrix. The diluent may be silicon carbide, graphite, amorphous carbon, alumina, or silica. The combined boron carbide-diluent phase contains no more than 2 percent B 2 O 3 , and the neutron-absorbing article contains from 20 to 40 percent phenol resin. The ratio of boron carbide to diluent particles is in the range 1:9 to 9:1

  1. Neutron detector assembly

    International Nuclear Information System (INIS)

    Hanai, Koi; Shirayama, Shinpei.

    1978-01-01

    Purpose: To prevent gamma-ray from leaking externally passing through the inside of a neutron detector assembly. Constitution: In a neutron detector assembly having a protection pipe formed with an enlarged diameter portion which serves also as a spacer, partition plates with predetermined width are disposed at the upper and the lower portions in this expanded portion. A lot of metal particles are filled into spaces formed by the partition plates. In such a structure, the metal particles well-absorb the gamma-rays from above and convert them into heat to provide shielding for the gamma-rays. (Horiuchi, T.)

  2. Boron Activated Neutron Thermometer

    Energy Technology Data Exchange (ETDEWEB)

    Lapsley, A. C. [Argonne National Lab. (ANL), Argonne, IL (United States). Instrument Research & Development

    1952-01-09

    The Brown Instrument Division of Minneapolis-Honeywell Regulator Co. have been making pilot models of boron coated neutron sensitive thermopiles, which show considerable promise of being effective indicators of slow neutron flux. Their loss in sensitivity in a year of operation in the maximum flux of CP-6 calculates to be less than 6 per cent. When used as rooftop indicators, the ratio of the signal of the two units would change by about 2 per cent in a year's time.

  3. Nuclear physics and neutronics

    International Nuclear Information System (INIS)

    Paya, D.

    1997-01-01

    After a brief review of the beginnings of the nuclear reaction physics in France in the 40's and 50's, the experimentation neutronics and nuclear physics studies are related and their uses presented, which aims were to provide data for the study of the various reactor concepts and to study fundamental physics. Progressively, pure nuclear physics lost its links with neutronics, and its influence decreases more or less. Long life radioactive waste reprocessing is an important domain where it could regain its contribution

  4. Simplified fast neutron dosimeter

    International Nuclear Information System (INIS)

    Sohrabi, M.

    1979-01-01

    Direct fast-neutron-induced recoil and alpha particle tracks in polycarbonate films may be enlarged for direct visual observation and automated counting procedures employing electrochemical etching techniques. Electrochemical etching is, for example, carried out in a 28% KOH solution at room temperature by applying a 2000 V peak-to-peak voltage at 1 kHz frequency. Such recoil particle amplification can be used for the detection of wide neutron dose ranges from 1 mrad to 1000 rads or higher, if desired. 5 claims

  5. Neutron cross sections

    CERN Document Server

    Hughes, Donald J; Dunworth, J V

    1957-01-01

    Neutron Cross Sections presents the principles of cross-section measurement and use, as well as sufficient theory so that the general behavior of cross sections is made understandable. This compilation is a direct result of experiences connected with the collection and evaluation of cross-section data during the past eight years at """"Sigma Centre"""", Brookhaven National Laboratory. Here, experimental results received from laboratories throughout the world are carefully evaluated and compiled in the curves and tables of the large volume Neutron Cross Sections, The most recent version of the

  6. Imaging with Polarized Neutrons

    Directory of Open Access Journals (Sweden)

    Nikolay Kardjilov

    2018-01-01

    Full Text Available Owing to their zero charge, neutrons are able to pass through thick layers of matter (typically several centimeters while being sensitive to magnetic fields due to their intrinsic magnetic moment. Therefore, in addition to the conventional attenuation contrast image, the magnetic field inside and around a sample can be visualized by detecting changes of polarization in a transmitted beam. The method is based on the spatially resolved measurement of the cumulative precession angles of a collimated, polarized, monochromatic neutron beam that traverses a magnetic field or sample.

  7. Fast neutron dosimetry

    International Nuclear Information System (INIS)

    DeLuca, P.M. Jr.; Pearson, D.W.

    1992-01-01

    This progress report concentrates on two major areas of dosimetry research: measurement of fast neutron kerma factors for several elements for monochromatic and white spectrum neutron fields and determination of the response of thermoluminescent phosphors to various ultra-soft X-ray energies and beta-rays. Dr. Zhixin Zhou from the Shanghai Institute of Radiation Medicine, People's Republic of China brought with him special expertise in the fabrication and use of ultra-thin TLD materials. Such materials are not available in the USA. The rather unique properties of these materials were investigated during this grant period

  8. Compact neutron flux monitor

    International Nuclear Information System (INIS)

    Madhavi, V.; Phatak, P.R.; Bahadur, C.; Bayala, A.K.; Jakati, R.K.; Sathian, V.

    2003-01-01

    Full text: A compact size neutron flux monitor has been developed incorporating standard boards developed for smart radiation monitors. The sensitivity of the monitors is 0.4cps/nV. It has been tested up to 2075 nV flux with standard neutron sources. It shows convincing results even in high flux areas like 6m away from the accelerator in RMC (Parel) for 106/107 nV. These monitors have a focal and remote display, alarm function with potential free contacts for centralized control and additional provision of connectivity via RS485/Ethernet. This paper describes the construction, working and results of the above flux monitor

  9. Fast neutron dosimetry

    International Nuclear Information System (INIS)

    DeLuca, P.M. Jr.; Pearson, D.W.

    1993-01-01

    Research concentrated on three major areas during the last twelve months: (1) investigations of energy fluence and absorbed dose measurements using crystalline and hot pressed TLD materials exposes to ultrasoft beams of photons, (2) fast neutron kerma factor measurements for several important elements as well as NE-213 scintillation material response function determinations at the intense ''white'' source available at the WNR facility at LAMPF, and (3) kerma factor ratio determinations for carbon and oxygen to A-150 tissue equivalent plastic at the clinical fast neutron radiation facility at Harper Hospital, Detroit, MI. Progress summary reports of these efforts are given in this report

  10. MCNP neutron benchmarks

    International Nuclear Information System (INIS)

    Hendricks, J.S.; Whalen, D.J.; Cardon, D.A.; Uhle, J.L.

    1991-01-01

    Over 50 neutron benchmark calculations have recently been completed as part of an ongoing program to validate the MCNP Monte Carlo radiation transport code. The new and significant aspects of this work are as follows: These calculations are the first attempt at a validation program for MCNP and the first official benchmarking of version 4 of the code. We believe the chosen set of benchmarks is a comprehensive set that may be useful for benchmarking other radiation transport codes and data libraries. These calculations provide insight into how well neutron transport calculations can be expected to model a wide variety of problems

  11. Delayed-neutron fraction in a pulsed spallation neutron source

    International Nuclear Information System (INIS)

    Carpenter, J.M.

    1980-02-01

    The fraction of delayed neutrons β (with T/sub 1/2/ greater than or equal to 0.025 s) in slow-neutron beams from a 238 U pulsed spallation neutron source is 0.0053 for 300 MeV protons. This measurement appears to be the first one of this quantity. The result indicates that, for most classes of measurements, the delayed-neutron background in time-of-flight instruments will be unimportant, and places constraints on the physics description of spallation targets. The measurement was performed at the prototype pulsed spallation neutron source, ZING-P', at Argonne National laboratory. 4 figures

  12. Scission neutron emission and prompt fission neutron spectrum

    CERN Document Server

    Kornilov, N V

    2001-01-01

    The mass, energy and angular integrated spectra of prompt fission neutrons for sup 2 sup 3 sup 5 U induced fission in the energy range from thermal to 5 MeV were analyzed. It allows assume that about 0.362+-0.025 neutrons per fission are emitted due to another mechanism then neutron emission from excited fragments after full acceleration. The spectrum of scission neutrons consists of two components with average energy 0.98 MeV and 2.74 MeV. The share of scission neutrons and their spectrum shape estimated in this work does not contradict to results of differential experiments analyzed in previous papers.

  13. Neutronic analysis of JET external neutron monitor response

    Energy Technology Data Exchange (ETDEWEB)

    Snoj, Luka, E-mail: luka.snoj@ijs.si [Reactor Physics Division, Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Lengar, Igor; Čufar, Aljaž [Reactor Physics Division, Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Syme, Brian; Popovichev, Sergey [Culham Centre for Fusion Energy, Culham Science Centre, Abingdon, OX14 3DB, United Kingdom (United Kingdom); Batistoni, Paola [ENEA C. R. Frascati, via E. Fermi 45, 00044 Frascati, Roma (Italy); Conroy, Sean [VR Association, Uppsala University, Department of Physics and Astronomy, PO Box 516, SE-75120 Uppsala (Sweden)

    2016-11-01

    Highlights: • We model JET tokamak containing JET remote handling system. • We investigate effect of remote handling system on external neutron monitor response. • Remote handling system correction factors are calculated. • Integral correction factors are relatively small, i.e up to 8%. - Abstract: The power output of fusion devices is measured in terms of the neutron yield which relates directly to the fusion yield. JET made a transition from Carbon wall to ITER-Like Wall (Beryllium/Tungsten/Carbon) during 2010–11. Absolutely calibrated measurement of the neutron yield by JET neutron monitors was ensured by direct measurements using a calibrated {sup 252}Cf neutron source (NS) deployed by the in-vessel remote handling system (RHS) inside the JET vacuum vessel. Neutronic calculations were required in order to understand the neutron transport from the source in the vacuum vessel to the fission chamber detectors mounted outside the vessel on the transformer limbs of the tokamak. We developed a simplified computational model of JET and the JET RHS in Monte Carlo neutron transport code MCNP and analyzed the paths and structures through which neutrons reach the detectors and the effect of the JET RHS on the neutron monitor response. In addition we performed several sensitivity studies of the effect of substantial massive structures blocking the ports on the external neutron monitor response. As the simplified model provided a qualitative picture of the process only, some calculations were repeated using a more detailed full 3D model of the JET tokamak.

  14. Characterization of neutron supermirror V-bender

    Energy Technology Data Exchange (ETDEWEB)

    Shin, E. J.; Seong, B. S.; Lee, J. S.; Hong, K. P.; Choi, B. H.; Lee, C. H

    2004-05-15

    Neutron supermirror is used not only for neutron guide tubes that their make it possible to transmit neutrons for long distance with low losses in intensity but for neutron benders used as a beam splitter. These devices are of main components of advanced neutron diffractometer or spectrometer with cold neutrons. In this report, the basic principles and applications of neutron guide tube and neutron supermirror as well as the performance test results of neutron V-bender were introduced. These information will be used for the development of advance cold neutron spectrometers in the future.

  15. Characterization of neutron supermirror V-bender

    International Nuclear Information System (INIS)

    Shin, E. J.; Seong, B. S.; Lee, J. S.; Hong, K. P.; Choi, B. H.; Lee, C. H.

    2004-05-01

    Neutron supermirror is used not only for neutron guide tubes that their make it possible to transmit neutrons for long distance with low losses in intensity but for neutron benders used as a beam splitter. These devices are of main components of advanced neutron diffractometer or spectrometer with cold neutrons. In this report, the basic principles and applications of neutron guide tube and neutron supermirror as well as the performance test results of neutron V-bender were introduced. These information will be used for the development of advance cold neutron spectrometers in the future

  16. Neutron transmission measurements at the IRMM pulsed neutron facility GELINA

    CERN Document Server

    Brusegan, A

    2002-01-01

    Measurements of neutron transmission are performed at the pulsed neutron source GELINA (Geel Linear Accelerator) of the JRC Institute of Reference Materials and Measurements in Belgium. This white neutron possibility is one of the world best as it posses an excellent energy resolution and good intensity, which offer the possibility of obtaining high quality neutron data. In the lecture are given typical characteristics of the time-of-flight (TOF) measurements performed here. The neutron transmission through a sample is connected directly with the total neutron cross section of the isotope. The precision of the experimental data is important for the exact determination of the neutron resonance parameters, which are relevant in applications like astrophysics and nuclear reactor design. The knowledge of the average nuclear properties, like the strength function, is desirable in nuclear reaction theory for comparison with predictions of different optical models. High quality of the transmission data is assured by...

  17. The Los Alamos Neutron Science Center Spallation Neutron Sources

    Science.gov (United States)

    Nowicki, Suzanne F.; Wender, Stephen A.; Mocko, Michael

    The Los Alamos Neutron Science Center (LANSCE) provides the scientific community with intense sources of neutrons, which can be used to perform experiments supporting civilian and national security research. These measurements include nuclear physics experiments for the defense program, basic science, and the radiation effect programs. This paper focuses on the radiation effects program, which involves mostly accelerated testing of semiconductor parts. When cosmic rays strike the earth's atmosphere, they cause nuclear reactions with elements in the air and produce a wide range of energetic particles. Because neutrons are uncharged, they can reach aircraft altitudes and sea level. These neutrons are thought to be the most important threat to semiconductor devices and integrated circuits. The best way to determine the failure rate due to these neutrons is to measure the failure rate in a neutron source that has the same spectrum as those produced by cosmic rays. Los Alamos has a high-energy and a low-energy neutron source for semiconductor testing. Both are driven by the 800-MeV proton beam from the LANSCE accelerator. The high-energy neutron source at the Weapons Neutron Research (WNR) facility uses a bare target that is designed to produce fast neutrons with energies from 100 keV to almost 800 MeV. The measured neutron energy distribution from WNR is very similar to that of the cosmic-ray-induced neutrons in the atmosphere. However, the flux provided at the WNR facility is typically 5×107 times more intense than the flux of the cosmic-ray-induced neutrons. This intense neutron flux allows testing at greatly accelerated rates. An irradiation test of less than an hour is equivalent to many years of neutron exposure due to cosmic-ray neutrons. The low-energy neutron source is located at the Lujan Neutron Scattering Center. It is based on a moderated source that provides useful neutrons from subthermal energies to ∼100 keV. The characteristics of these sources, and

  18. Scintillating fibre tracking neutron detector

    International Nuclear Information System (INIS)

    Karlsson, Joakim.

    1995-04-01

    A detector for measurements of collimated fluxes of neutrons in the energy range 2-20 MeV is proposed. It utilizes (n.p) elastic scattering in scintillating optical fibres placed in successive orthogonal layers perpendicular to the neutron flux. A test module has been designed, constructed and tested with respect to separation of neutron and gamma events. The pulse height measurements show the feasibility to discriminate between neutron, gamma and background events. Application to measurements of fusion neutrons is considered. 18 refs, 22 figs, 4 tabs

  19. Shielding around spallation neutron sources

    International Nuclear Information System (INIS)

    Fragopoulou, M; Manolopoulou, M; Stoulos, S; Brandt, R; Westmeier, W; Krivopustov, M; Sosnin, A; Golovatyuk, S; Zamani, M

    2006-01-01

    Spallation neutron sources provide more intense and harder neutron spectrum than nuclear reactors for which a substantial amount of shielding measurements have been performed. Although the main part of the cost for a spallation station is the cost of the shielding, measurements regarding shielding for the high energy neutron region are still very scarce. In this work calculation of the neutron interaction length in polyethylene moderator for different neutron energies is presented. Measurements which were carried out in Nuclotron accelerator at the Laboratory of High Energies (Joint Institute for Nuclear Research, Dubna) and comparison with calculation are also presented. The measurements were performed with Solid State Nuclear Track Detectors (SSNTDs)

  20. BR2 reactor neutron beams

    International Nuclear Information System (INIS)

    Neve de Mevergnies, M.

    1977-01-01

    The use of reactor neutron beams is becoming increasingly more widespread for the study of some properties of condensed matter. It is mainly due to the unique properties of the ''thermal'' neutrons as regards wavelength, energy, magnetic moment and overall favorable ratio of scattering to absorption cross-sections. Besides these fundamental reasons, the impetus for using neutrons is also due to the existence of powerful research reactors (such as BR2) built mainly for nuclear engineering programs, but where a number of intense neutron beams are available at marginal cost. A brief introduction to the production of suitable neutron beams from a reactor is given. (author)

  1. Studies on airborne dust particles by neutron activation analysis

    International Nuclear Information System (INIS)

    Aoki, Atsushi; Ishii, Taka; Tomiyama, Tsuyoshi; Yamamoto, Isao.

    1974-01-01

    Neutron activation analysis was performed on the airborne dust particles collected at six places with different contaminating circumstances in Kyoto city and the suburbs of Okayama city, using an open type low volume air sampler with a membrance filter attached. Radioactivation by neutrons was performed with the reactor in the Research Reactor Institute of Kyoto University. Short half-life nuclides activated by thermal neutrons were measured. The concentration of airborne dust was usually high in November and December, while Na, Mn, K, etc. probably owing to soil origin showed similar seasonal change to the dust particles, as expected. The concentrations Cl and Br were in proportion to traffic volume, and it was considered to be caused by the exhaust gas from cars. Zn, V. et. were thick in factory areas, which seemed to show the relationship with oil fuel consumption. (Kobatake, H.)

  2. The activation method for determining neutron spectra and fluences

    International Nuclear Information System (INIS)

    Hogel, J.; Vespalec, R.

    1980-01-01

    3 mm thick foils of 4 and 17 mm in diameter were used for measurements. NaI scintillation detectors 45 mm in diameter by 50 mm thick and 40 mm in diameter by 1 mm thick, and a Ge-Li spectrometer of 53 cm 3 in volume were used for gamma detection. A photopeak or a certain part of the integral spectrum was measured for each radionuclide. Computer code PIKAR was applied in automatic calculation of a simple gamma spectrum obtained using the semiconductor spectrometer. The FACT code was used for calculating foil activity. Codes SAND II and RFSP were used for neutron spectra unfolding. Ge-Li detector spectrometry was used for determining neutron fluence. Code FLUE was used for determining the mean value of neutron flux density and fluence. (J.P.)

  3. More accurate thermal neutron coincidence counting technique

    International Nuclear Information System (INIS)

    Baron, N.

    1978-01-01

    Using passive thermal neutron coincidence counting techniques, the accuracy of nondestructive assays of fertile material can be improved significantly using a two-ring detector. It was shown how the use of a function of the coincidence count rate ring-ratio can provide a detector response rate that is independent of variations in neutron detection efficiency caused by varying sample moderation. Furthermore, the correction for multiplication caused by SF- and (α,n)-neutrons is shown to be separable into the product of a function of the effective mass of 240 Pu (plutonium correction) and a function of the (α,n) reaction probability (matrix correction). The matrix correction is described by a function of the singles count rate ring-ratio. This correction factor is empirically observed to be identical for any combination of PuO 2 powder and matrix materials SiO 2 and MgO because of the similar relation of the (α,n)-Q value and (α,n)-reaction cross section among these matrix nuclei. However the matrix correction expression is expected to be different for matrix materials such as Na, Al, and/or Li. Nevertheless, it should be recognized that for comparison measurements among samples of similar matrix content, it is expected that some function of the singles count rate ring-ratio can be defined to account for variations in the matrix correction due to differences in the intimacy of mixture among the samples. Furthermore the magnitude of this singles count rate ring-ratio serves to identify the contaminant generating the (α,n)-neutrons. Such information is useful in process control

  4. Diverse Neutron Scattering Measurements in Unconventional Superconductors

    Science.gov (United States)

    Carr, Scott

    Superconductivity is an amazing phenomena. Beyond the eye-popping demos and promises of floating trains, it is a macroscopic manifestation of pure quantum physics. Where most quantum effects are smothered by thermal energy even at the lowest of temperatures, superconductivity brings the strangeness of quantum mechanics to reasonably accessible temperatures. An while it does have applications in terms of efficient charge transfer and the production of powerful magnetic fields, this is not why we study it. The mystery of its origin, oddness of its effects, and beauty of its consequences drives us to delve into the richness of this amazing phenomena. One key player in the physics of these exotic superconductors appears to be magnetism. Magnetism is a constant presence in the phase diagrams of exotic superconductors and appears to couple to the superconducting transition in some interesting ways. The details of the connection remain unknown, but it is clear that magnetism, either through static order, fluctuations, or both, is an important aspect of the crystalline environments which foster superconductivity. Through the tool of neutron scattering I investigate this connection across an array or different compounds using a variety of techniques. In this thesis, I conclude on the role of phase separation in superconducting K yFe1.6+xSe2 using neutron diffraction, perform a survey of magnetic excitations across the superconducting phase diagram in NaFe1-xCoxAs with neutron time-of-flight spectroscopy, and reveal new magnetic properties of the old heavy fermion superconductor UPt3 via more traditional neutron measurements.

  5. Optimization of neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Hooper, E.B.

    1993-11-09

    I consider here the optimization of the two component neutron source, allowing beam species and energy to vary. A simple model is developed, based on the earlier publications, that permits the optimum to be obtained simply. The two component plasma, with one species of hot ion (D{sup +} or T{sup +}) and the complementary species of cold ion, is easy to analyze in the case of a spatially uniform cold plasma, as to good approximation the total number of hot ions is important but not their spatial distribution. Consequently, the optimization can ignore spatial effects. The problem of a plasma with both types of hot ions and cold ions is rather more difficult, as the neutron production by hot-hot interactions is sensitive to their spatial distributions. Consequently, consideration of this problem will be delayed to a future memorandum. The basic model is that used in the published articles on the two-component, beam-plasma mirror source. I integrate the Fokker-Planck equation analytically, obtaining good agreement with previous numerical results. This simplifies the optimization, by providing a functional form for the neutron production. The primary result is expressed in terms of the power efficiency: watts of neutrons/watts of primary power. The latter includes the positive ion neutralization efficiency. At 150 keV, the present model obtains an efficiency of 0.66%, compared with 0.53% of the earlier calculation.

  6. Advances in neutron tomography

    Indian Academy of Sciences (India)

    much improved test experiments using polarized neutrons for radiographic imaging. For this purpose the CONRAD instrument of the HMI was equipped with polarizing and analysing benders very similar to conventional scattering experiments using polarized neu- trons. Magnetic fields in different coils and in samples ...

  7. New Neutron Dosimeter

    CERN Multimedia

    2001-01-01

    CERN has been operating an Individual Dosimetry Service for neutrons for about 35 years. The service was based on nuclear emulsions in the form of film packages which were developed and scanned in the Service. In 1999, the supplier of theses packages informed CERN that they will discontinue production of this material. TIS-RP decided to look for an external service provider for individual neutron dosimetry. After an extensive market survey and an invitation for tender, a supplier that met the stringent technical requirements set up by CERN's host states for personal dosimeters was identified. The new dosimeter is based on a track-etching technique. Neutrons have the capability of damaging plastic material. The microscopic damage centres are revealed by etching them in a strong acid. The resulting etch pits can be automatically counted and their density is proportional to dose equivalent from neutrons. On the technical side, the new dosimeter provides an improved independence of its response from energy and th...

  8. Neutron scattering from fractals

    DEFF Research Database (Denmark)

    Kjems, Jørgen; Freltoft, T.; Richter, D.

    1986-01-01

    -angle neutron scattering studies of the variation with aggregation rate are presented. These results allow a very detailed comparison to be made with the theoretical scattering curves. Preliminary incoherent inelastic data on the low-frequency dynamics of hydroxylated silica particle aggregates show a clear...

  9. Small angle neutron scattering

    International Nuclear Information System (INIS)

    Gupta, Sanjay

    1982-01-01

    The technique of small angle neutron scattering was first used in Germany less than two decades ago. Since then it has developed very rapidly, and today it is regarded as one of the most powerful techniques in materials, chemical and biological research. During the last decade the combination of high flux reactors and sophisticated instrumentation has revolutionized the technique. This paper endeavours to present a brief but comprehensive review of small angle scattering of neutrons and its applications in solid state research. The domain in which small angle neutron scattering is particularly useful is delineated and some of the methods used in the analysis of data are discussed with special emphasis on recent developments. Typical small angle neutron scattering cameras are described. Finally some experimental results on heterogeneities in metallic systems (both static and dynamic studies), radiation damage in materials, superconductivity, magnetic materials and the technologically very important area of non-destructive testing are reviewed in order to illustrate the wide range of applicability of this technique to problems in solid state research. (author)

  10. Neutron resonance absorption theory

    International Nuclear Information System (INIS)

    Reuss, P.

    1991-11-01

    After some recalls on the physics of neutron resonance absorption during their slowing down, this paper presents the main features of the theoretical developments performed by the french school of reactor physics: the effective reaction rate method so called Livolant-Jeanpierre theory, the generalizations carried out by the author, and the probability table method [fr

  11. Neutron rich nuclei

    International Nuclear Information System (INIS)

    Foucher, R.

    1979-01-01

    If some β - emitters are particularly interesting to study in light, medium, and heavy nuclei, another (and also) difficult problem is to know systematically the properties of these neutron rich nuclei far from the stability line. A review of some of their characteristics is presented. How far is it possible to be objective in the interpretation of data is questioned and implications are discussed

  12. Neutron protein crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Niimura, Nobuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-10-01

    X-ray diffraction of single crystal has enriched the knowledge of various biological molecules such as proteins, DNA, t-RNA, viruses, etc. It is difficult to make structural analysis of hydrogen atoms in a protein using X-ray crystallography, whereas neutron diffraction seems usable to directly determine the location of those hydrogen atoms. Here, neutron diffraction method was applied to structural analysis of hen egg-white lysozyme. Since the crystal size of a protein to analyze is generally small (5 mm{sup 3} at most), the neutron beam at the sample position in monochromator system was set to less than 5 x 5 mm{sup 2} and beam divergence to 0.4 degree or less. Neutron imaging plate with {sup 6}Li or Gd mixed with photostimulated luminescence material was used and about 2500 Bragg reflections were recorded in one crystal setting. A total of 38278 reflections for 2.0 A resolution were collected in less than 10 days. Thus, stereo views of Trp-111 omit map around the indol ring of Trp-111 was presented and the three-dimensional arrangement of 696H and 264D atoms in the lysozyme molecules was determined using the omit map. (M.N.)

  13. Applied neutron resonance theory

    International Nuclear Information System (INIS)

    Froehner, F.H.

    1978-07-01

    Utilisation of resonance theory in basic and applications-oriented neutron cross section work is reviewed. The technically important resonance formalisms, principal concepts and methods as well as representative computer programs for resonance parameter extraction from measured data, evaluation of resonance data, calculation of Doppler-broadened cross sections and estimation of level-statistical quantities from resonance parameters are described. (orig.) [de

  14. Study of 24Na activity in concrete using 20-MeV proton beam on Cu

    International Nuclear Information System (INIS)

    Oranj, Leila Mokhtanri; Jung, Nam Suk; Lee, Arim; Heo, Tae Min; Bakhtian, Mahdi; Lee, Hee Seock

    2017-01-01

    The number of medical cyclotrons capable of accelerating protons to about 20 MeV is increasing in Korea. In such facilities, various radionuclides could be induced in shielding materials like concrete from secondary neutrons which Causes problems from the view point of radiation safety. Among these radionuclides, gamma-ray from 24 Na (Tz1/2 = 15 h) is the most important origin of radiation exposure. 24 Na could be produced from secondary neutrons on Na, Al and Mg component which exist in the concrete. 24 Na Could be produced from thermal neutrons on Na and fast neutron with energy lower than 20 MeV on Al and Mg. Due to interaction of 20 MeV protons on Cu target, secondary neutrons with the energy of less than 20 MeV were produced. therefore, among the concrete components, Na, Al and Mg are only corespondent to produce 24 Na. In this work, 24 Na activity induced in concrete and chemical reagents of concrete (NaHCO 3 , Al 2 O 3 and MgO) were measured. To produce neutrons, Cu target was irradiated by 20 MeV protons. Measured data were compared with results of simulations by FLUKA and MARS as well as earlier works and theocratical data. In the case of Mg and Al chemical reagents, FLUKA code overestimates our measurements by approximately four times, while, for Na sample, FLUKA underestimates the experimental data by almost 0.5. Data from FLUKA and measurement for the concrete are consistent. Calculation from TALYS for Mg overestimates the measured data by a factor of 2.5.

  15. Clinical application of fast neutrons

    International Nuclear Information System (INIS)

    Battermann, J.J.

    1981-01-01

    The results of treatments and clinical experiments with neutrons (from a medical d+T neutron generator with an output of 10 12 neutrons per second) are reported and discussed. Data on RBE values are presented after single doses and multiple fractions of neutrons and 60 Co-gamma rays on pulmonary metastases. The results of pilot studies on head and neck tumours, brain tumours and pelvic tumours are discussed. The accuracy of the calculated dose is tested with some in-vivo experiments during neutron irradiation of the pelvis. Estimations of RBE values for tumour control, skin damage and intestinal damage after fractionated neutron therapy are dealt with and the results obtained in treatment of sarcomas are discussed. The preliminary results are given of some clinical trials in Amsterdam. Also some data from other centres are reviewed. From these data some remarks about the future of neutron therapy are made. (Auth.)

  16. A neutron well logging system

    International Nuclear Information System (INIS)

    1980-01-01

    A pulsed neutron well logging system using a sealed off neutron generator tube is provided with a programmable digital neutron output control system. The control system monitors the target beam current and compares a function of this current with a pre-programmed control function to develop a control signal for the neutron generator. The control signal is used in a series regulator to control the average replenisher current of the neutron generator tube. The programmable digital control system of the invention also provides digital control signals as a function of time to provide ion source voltages. This arrangement may be utilized to control neutron pulses durations and repetition rates or to produce other modulated wave forms for intensity modulating the output of the neutron generator as a function of time. (Auth.)

  17. Nanostructure Neutron Converter Layer Development

    Science.gov (United States)

    Park, Cheol (Inventor); Sauti, Godfrey (Inventor); Kang, Jin Ho (Inventor); Lowther, Sharon E. (Inventor); Thibeault, Sheila A. (Inventor); Bryant, Robert G. (Inventor)

    2016-01-01

    Methods for making a neutron converter layer are provided. The various embodiment methods enable the formation of a single layer neutron converter material. The single layer neutron converter material formed according to the various embodiments may have a high neutron absorption cross section, tailored resistivity providing a good electric field penetration with submicron particles, and a high secondary electron emission coefficient. In an embodiment method a neutron converter layer may be formed by sequential supercritical fluid metallization of a porous nanostructure aerogel or polyimide film. In another embodiment method a neutron converter layer may be formed by simultaneous supercritical fluid metallization of a porous nanostructure aerogel or polyimide film. In a further embodiment method a neutron converter layer may be formed by in-situ metalized aerogel nanostructure development.

  18. A detector for neutron imaging

    CERN Document Server

    Britton, C L; Wintenberg, A L; Warmack, R J; McKnight, T E; Frank, S S; Cooper, R G; Dudney, N J; Veith, G M; Stephan, A C

    2004-01-01

    A bright neutron source such as the Spallation Neutron Source (SNS) places extreme requirements on detectors including excellent 2-D spatial imaging and high dynamic range. Present imaging detectors have either shown position resolutions that are less than acceptable or they exhibit excessive paralyzing dead times due to the brightness of the source. High neutron detection efficiency with good neutron- gamma discrimination is critical for applications in neutron scattering research where the usefulness of the data is highly dependent on the statistical uncertainty associated with each detector pixel.. A detector concept known as MicroMegas (MicroMEsh GAseous Structure) has been developed at CERN in Geneva for high- energy physics charged-particle tracking applications and has shown great promise for handling high data rates with a rather low-cost structure. We are attempting to optimize the MicroMegas detector concept for thermal neutrons and have designed a 1-D neutron strip detector which we have tested In ...

  19. Texture studies using neutron diffraction

    International Nuclear Information System (INIS)

    Szpunar, J.A.

    1984-01-01

    Various aspects of the application of neutron scattering methods to texture studies are reviewed. The neutron method is compared with other methods of texture measurement and techniques of neutron diffraction registration of texture are discussed. Examples are presented of the use of neutron scattering for texture examination in materials having various grain sizes and degrees of structural inhomogeneity. It is also demonstrated that the information about texture can be used in the discussion of the deformation and recrystallization processes in metals. Neutron diffraction results are shown to be helpful in the examination of the influence of texture on the anisotropy of physical properties in materials. The possibility of neutron diffraction measurements of magnetic texture is reported. Finally the accuracy of texture measurements using the neutron method is discussed. (author)

  20. New techniques in neutron scattering

    International Nuclear Information System (INIS)

    Hayter, J.B.

    1993-01-01

    New neutron sources being planned, such as the Advanced Neutron Source (ANS) or the European Spallation Source (ESS), will provide an order of magnitude flux increase over what is available today, but neutron scattering will still remain a signal-limited technique. At the same time, the development of new materials, such as polymer and ceramic composites or a variety of complex fluids, will increasingly require neutron-based research. This paper will discuss some of the new techniques which will allow us to make better use of the available neutrons, either through improved instrumentation or through sample manipulation. Discussion will center primarily on unpolarized neutron techniques since polarized neutrons will be the subject of the next paper. (author)

  1. Neutron imaging and tomography with MCPs

    OpenAIRE

    Pinto, Serge Duarte; Ortega, Raquel; Ritzau, Steve; Pasquale, David; Laprade, Bruce; Mrotek, Sharon; Gardell, Sean; Zhou, Zhou; Plomp, Jeroen; van Eijck, Lambert; Bilheux, Hassina; Dhiman, Indu

    2017-01-01

    A neutron imaging detector based on neutron-sensitive microchannel plates (MCPs) was constructed and tested at beamlines of thermal and cold neutrons. The MCPs are made of a glass mixture containing B-10 and natural Gd, which makes the bulk of the MCP an efficient neutron converter. Contrary to the neutron sensitive scintillator screens normally used in neutron imaging, spatial resolution is not traded off with detection efficiency. While the best neutron imaging scintillators have a detectio...

  2. Effects of Hot-Spot Geometry on Backscattering and Down-Scattering Neutron Spectra

    Science.gov (United States)

    Mohamed, Z. L.; Mannion, O. M.; Forrest, C. J.; Knauer, J. P.; Anderson, K. S.; Radha, P. B.

    2017-10-01

    The measured neutron spectrum produced by a fusion experiment plays a key role in inferring observable quantities. One important observable is the areal density of an implosion, which is inferred by measuring the scattering of neutrons. This project seeks to use particle-transport simulations to model the effects of hot-spot geometry on backscattering and down-scattering neutron spectra along different lines of sight. Implosions similar to those conducted at the Laboratory of Laser Energetics are modeled by neutron transport through a DT plasma and a DT ice shell using the particle transport codes MCNP and IRIS. Effects of hot-spot geometry are obtained by ``detecting'' scattered neutrons along different lines of sight. This process is repeated for various hot-spot geometries representing known shape distortions between the hot spot and the shell. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  3. The magnetic diffusion of neutrons; La diffusion magnetique des neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, W.C. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    The purpose of this report is to examine briefly the diffusion of neutrons by substances, particularly by crystals containing permanent atomic or ionic magnetic moments. In other words we shall deal with ferromagnetic, antiferromagnetic, ferrimagnetic or paramagnetic crystals, but first it is necessary to touch on nuclear diffusion of neutrons. We shall start with the interaction of the neutron with a single diffusion centre; the results will then be applied to the magnetic interactions of the neutron with the satellite electrons of the atom; finally we shall discuss the diffusion of neutrons by crystals. (author) [French] Le but de ce rapport est d'examiner, brievement, la diffusion des neutrons par les substances, et surtout, par des cristaux qui contiennent des moments magnetiques atomiques ou ioniques permanents. C'est-a-dire que nous nous interesserons aux cristaux ferromagnetiques, antiferromagnetiques, ferrimagnetiques ou paramagnetiques; il nous faut cependant rappeler d'abord la diffusion nucleaire des neutrons. Nous commencerons par l'interaction du neutron avec un seul centre diffuseur; puis les resultats seront appliques aux interactions magnetiques du neutron avec les electrons satellites de l'atome; enfin nous discuterons la diffusion des neutrons par les cristaux. (auteur)

  4. Pulsed neutron uranium borehole logging with prompt fission neutrons

    International Nuclear Information System (INIS)

    Bivens, H.M.; Smith, G.W.; Jensen, D.H.

    1976-01-01

    The gross count natural gamma log normally used for uranium borehole logging is seriously affected by disequilibrium. Methods for the direct measurement of uranium, such as neutron logging, which are not affected by disequilibrium have been the object of considerable effort in recent years. This paper describes a logging system for uranium which uses a small accelerator to generate pulses of 14 MeV neutrons to detect and assay uranium by the measurement of prompt fission neutrons in the epithermal energy range. After an initial feasibility study, a prototype logging probe was built for field evaluation which began in January 1976. Physical and operational characteristics of the prototype probe, the neutron tube-transformer assembly, and the neutron tube are described. In logging operations, only the epithermal prompt fission neutrons detected between 250 microseconds to 2500 microseconds following the excitation neutron pulse are counted. Comparison of corrected neutron logs with the conventional gross count natural gamma logs and the chemical assays of cores from boreholes are shown. The results obtained with this neutron probe clearly demonstrate its advantages over the gross count natural gamma log, although at this time the accuracy of the neutron log assay is not satisfactory under some conditions. The necessary correction factors for various borehole and formation parameters are being determined and, when applied, should improve the assay accuracy

  5. Measurement of excitation energy of neutron-rich precursor fragments

    Science.gov (United States)

    Mosby, Michelle Anthea

    Projectile fragmentation forms the basis for beam production at radioactive beam facilities such as the National Superconducting Cyclotron Laboratory (NSCL), yet uncertainties remain about the specifics of the production mechanism. For example, very little is known about the excitation energy of the precursors of the observed final fragments. In the present work, isotopes of sodium, neon, and fluorine produced in the fragmentation of a 32 Mg beam at 86 MeV/nucleon in a beryllium target, ranging in mass loss from DeltaA = 3--12, were observed and the coincident neutrons were detected using the Modular Neutron Array (MoNA). Neutron hit multiplicity in MoNA was compared to output from the statistical evaporation model PACE which was passed through a GEANT4 simulation to account for detector response with a X2v analysis. The neutron hit multiplicity distributions were used to determine the mass loss and excitation energy of the precursor fragments created in the fast step of the reaction. The mass loss and excitation energy were compared to abrasion/ablation models and an internuclear cascade model, ISABEL. For sodium and neon observed fragments, a single precursor mass was found, with a wide range of high excitation energies, up to 60 MeV. Observed fluorine isotopes were also found to have high excitation energies, ranging from 40--80 MeV, but with some variation in precursor mass.

  6. Neutron beam design for low intensity neutron and gamma-ray radioscopy using small neutron sources

    CERN Document Server

    Matsumoto, T

    2003-01-01

    Two small neutron sources of sup 2 sup 5 sup 2 Cf and sup 2 sup 4 sup 1 Am-Be radioisotopes were used for design of neutron beams applicable to low intensity neutron and gamma ray radioscopy (LINGR). In the design, Monte Carlo code (MCNP) was employed to generate neutron and gamma ray beams suited to LINGR. With a view to variable neutron spectrum and neutron intensity, various arrangements were first examined, and neutron-filter, gamma-ray shield and beam collimator were verified. Monte Carlo calculations indicated that with a suitable filter-shield-collimator arrangement, thermal neutron beam of 3,900 ncm sup - sup 2 s sup - sup 1 with neutron/gamma ratio of 7x10 sup 7 , and 25 ncm sup - sup 2 s sup - sup 1 with very large neutron/gamma ratio, respectively, could be produced by using sup 2 sup 5 sup 2 Cf(122 mu g) and a sup 2 sup 4 sup 1 Am-Be(37GBq)radioisotopes at the irradiation port of 35 cm from the neutron sources.

  7. Measurements of keV-neutron capture γ rays of fission products. 2

    International Nuclear Information System (INIS)

    Igashira, Masayuki

    1996-01-01

    γ rays from the keV-neutron capture reactions by 140 Ce, 141 Pr, and 147,148,149,150 Sm have been measured in a neutron energy region of 10 to 550 keV, using a large anti-Compton NaI(Tl) γ-ray spectrometer and the 7 Li(p,n) 7 Be pulsed neutron source with a 3-MV Pelletron accelerator. The preliminary results for the capture cross sections and γ-ray spectra of those nuclei are presented and discussed. (author)

  8. Measurements of keV-neutron capture {gamma} rays of fission products. 3

    Energy Technology Data Exchange (ETDEWEB)

    Igashira, Masayuki [Tokyo Inst. of Tech. (Japan). Research Lab. for Nuclear Reactors

    1997-03-01

    {gamma} rays from the keV-neutron capture reactions by {sup 143,145}Nd and {sup 153}Eu have been measured in a neutron energy region of 10 to 80 keV, using a large anti-Compton NaI(Tl) {gamma}-ray spectrometer and the {sup 7}Li(p,n){sup 7}Be pulsed neutron source with a 3-MV Pelletron accelerator. The preliminary results for the capture cross sections and {gamma}-ray spectra of those nuclei are presented and discussed. (author)

  9. Observation of a low-lying neutron-unbound state in 19C

    International Nuclear Information System (INIS)

    Thoennessen, M.; Mosby, S.; Badger, N.S.; Baumann, T.; Bazin, D.; Bennett, M.; Brown, J.; Christian, G.; DeYoung, P.A.; Finck, J.E.; Gardner, M.; Hook, E.A.; Luther, B.; Meyer, D.A.; Mosby, M.; Rogers, W.F.

    2013-01-01

    Proton removal reactions from a secondary 22 N beam were utilized to populate unbound states in neutron-rich carbon isotopes. Neutrons were measured with the Modular Neutron Array (MoNA) in coincidence with carbon fragments. A resonance with a decay energy of 76(14) keV was observed in the system 18 C+n corresponding to a state in 19 C at an excitation energy of 653(95) keV. This resonance could correspond to the first 5/2 + state which was recently speculated to be unbound in order to describe 1n and 2n removal cross section measurements from 20 C

  10. Observation of a low-lying neutron-unbound state in 19C

    Science.gov (United States)

    Thoennessen, M.; Mosby, S.; Badger, N. S.; Baumann, T.; Bazin, D.; Bennett, M.; Brown, J.; Christian, G.; DeYoung, P. A.; Finck, J. E.; Gardner, M.; Hook, E. A.; Luther, B.; Meyer, D. A.; Mosby, M.; Rogers, W. F.; Smith, J. K.; Spyrou, A.; Strongman, M. J.

    2013-08-01

    Proton removal reactions from a secondary 22N beam were utilized to populate unbound states in neutron-rich carbon isotopes. Neutrons were measured with the Modular Neutron Array (MoNA) in coincidence with carbon fragments. A resonance with a decay energy of 76(14) keV was observed in the system C18+n corresponding to a state in 19C at an excitation energy of 653(95) keV. This resonance could correspond to the first 5/2+ state which was recently speculated to be unbound in order to describe 1n and 2n removal cross section measurements from 20C.

  11. Characterization of Phoenician pottery from Mothia by neutron activation analysis

    International Nuclear Information System (INIS)

    Cesana, A.; Terrani, M.; Cuomo di Caprio, N.; Tusa, V.

    1983-01-01

    The concentration of 7 elements (Na, Al, Mg, Ti, Ca, V, Mn) was determined by neutron activation analysis in 35 samples of pottery and 14 samples of clay. The samples were collected in ancient Mothia (Sicily) and in its neighbourhoods. Cluster analysis of the data showed that most of the samples are homogeneous and confirmed the archaeological evidence that they are mostly local wer ware. The detailed results of the analyses are reported and the technique used for cluster analysis is described. (author)

  12. Diagnostic Application of Absolute Neutron Activation Analysis in Hematology

    Energy Technology Data Exchange (ETDEWEB)

    Zamboni, C.B.; Oliveira, L.C.; Dalaqua, L. Jr.

    2004-10-03

    The Absolute Neutron Activation Analysis (ANAA) technique was used to determine element concentrations of Cl and Na in blood of healthy group (male and female blood donators), select from Blood Banks at Sao Paulo city, to provide information which can help in diagnosis of patients. This study permitted to perform a discussion about the advantages and limitations of using this nuclear methodology in hematological examinations.

  13. A study on cigarette tobacco by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Md Soot Haji Ahmad; Tey Nsan Yen

    1987-01-01

    The concentration of 25 elements in cigarette tobacco of popular brands locally marketed were determined using instrumental neutron activation analysis. These elements are: Al, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Eu, Fe, Hf, Hg, K, La, Mg, Mn, Na, Rb, Sb, Sc, Se, Sr, Th, and Zn. Comparison of the element contents to the reported cigarette tobacco of Egypt, Iran and Turkey was also done. (author)

  14. Neutron activation analysis of cheese, eggs, fish, fowl and meats

    International Nuclear Information System (INIS)

    Zikovsky, L.; Soliman, K.

    2002-01-01

    The concentrations of Br, Ca, Cl, Cu, I, K, Mg, Na, Rb, S and Ti in 44 samples of cheese, eggs, fish, fowl and meats sold in Canada were determined with absolute instrumental neutron activation analysis. The procedure is fully computerized and incorporates one short irradiation and counting only. When an element was not detected, its detection limit was calculated. The nuclear interferences and blanks were taken into account. The nutritional significance of the results is discussed. (author)

  15. The Chi-Nu Program to Measure Prompt Fission Neutron Spectra - Progress and Plans

    Science.gov (United States)

    Haight, Robert; Wu, Ching-Yen; Perdue, Brent; Taddeucci, Terry; Lee, Hye Young; O'Donnell, John; Devlin, Matthew; Fotiades, Nikolaos; Ullmann, John; Nelson, Ronald; White, Morgan; Bredeweg, Todd; Neudecker, Denise; Rising, Michael; Wender, Stephen; Henderson, Roger

    2013-10-01

    New data on the prompt fission neutron spectra (PFNS) from neutron-induced fission are needed to resolve discrepancies in the literature and to achieve higher accuracies. The Chi-Nu project, conducted jointly by LANL and LLNL, aims to measure the PFNS for fission of 239Pu induced by neutrons from 0.5 to 20 MeV with accuracies of 3-5% in the outgoing energy from 0.1 to 9 MeV and 15% from 9 to 12 MeV. Neutrons from the WNR/LANSCE neutron source are being used with a Parallel-Plate Avalanche Counter (PPAC) to detect the fission event and two arrays of neutron detectors. Modeling of this and previous experiments has uncovered effects that open questions on reported accuracies in the literature data and that must be addressed in the present program. Challenges for the present experiment in background reduction, use of 239Pu in a PPAC, neutron detector response and data acquisition will be discussed. This work is performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and the Los Alamos National Laboratory under Contract DE-AC52-06NA25396.

  16. Rotational dynamics of propylene inside Na-Y zeolite cages

    Indian Academy of Sciences (India)

    We report here the quasielastic neutron scattering (QENS) studies on the dynamics of propylene inside Na-Y zeolite using triple axis spectrometer (TAS) at Dhruva reactor, Trombay. Molecular dynamics (MD) simulations performed on the system had shown that the rotational motion involves energy larger than that involved ...

  17. Source characterization of Purnima Neutron Generator (PNG)

    International Nuclear Information System (INIS)

    Bishnoi, Saroj; Patel, T.; Paul, Ram K.; Sarkar, P.S.; Adhikari, P.S.; Sinha, Amar

    2011-01-01

    The use of 14.1 MeV neutron generators for the applications such as elemental analysis, Accelerated Driven System (ADS) study, fast neutron radiography requires the characterization of neutron source i.e neutron yield (emission rate in n/sec), neutron dose, beam spot size and energy spectrum. In this paper, a series of experiments carried out to characterize this neutron source. The neutron source has been quantified with neutron emission rate, neutron dose at various source strength and beam spot size at target position

  18. neutron transmission through crystalline materials

    International Nuclear Information System (INIS)

    El Mesiry, M.S.

    2011-01-01

    The aim of the present work is to study the neutron transmission through crystalline materials. Therefore a study of pyrolytic graphite (PG) as a highly efficient selective thermal neutron filter and Iron single crystal as a whole one, as well as the applicability of using their polycrystalline powders as a selective cold neutron filters is given. Moreover, the use of PG and iron single crystal as an efficient neutron monochromator is also investigated. An additive formula is given which allows calculating the contribution of the total neutron cross-section including the Bragg scattering from different )(hkl planes to the neutron transmission through crystalline iron and graphite. The formula takes into account their crystalline form. A computer CFe program was developed in order to provide the required calculations for both poly- and single-crystalline iron. The validity of the CFe program was approved from the comparison of the calculated iron cross-section data with the available experimental ones. The CFe program was also adapted to calculate the reflectivity from iron single crystal when it used as a neutron monochromator The computer package GRAPHITE, developed in Neutron Physics laboratory, Nuclear Research Center, has been used in order to provide the required calculations for crystalline graphite in the neutron energy range from 0.1 meV to 10 eV. A Mono-PG code was added to the computer package GRAPHITE in order to calculate the reflectivity from PG crystal when it used as a neutron monochromator.

  19. Study on neutron irradiation behavior of beryllium as neutron multiplier

    Energy Technology Data Exchange (ETDEWEB)

    Ishitsuka, Etsuo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    1998-03-01

    More than 300 tons beryllium is expected to be used as a neutron multiplier in ITER, and study on the neutron irradiation behavior of beryllium as the neutron multiplier with Japan Materials Testing Reactor (JMTR) were performed to get the engineering data for fusion blanket design. This study started as the study on the tritium behavior in beryllium neutron reflector in order to make clear the generation mechanism on tritium of JMTR primary coolant since 1985. These experiences were handed over to beryllium studies for fusion study, and overall studies such as production technology of beryllium pebbles, irradiation behavior evaluation and reprocessing technology have been started since 1990. In this presentation, study on the neutron irradiation behavior of beryllium as the neutron multiplier with JMTR was reviewed from the point of tritium release, thermal properties, mechanical properties and reprocessing technology. (author)

  20. Study on neutron irradiation behavior of beryllium as neutron multiplier

    International Nuclear Information System (INIS)

    Ishitsuka, Etsuo

    1998-01-01

    More than 300 tons beryllium is expected to be used as a neutron multiplier in ITER, and study on the neutron irradiation behavior of beryllium as the neutron multiplier with Japan Materials Testing Reactor (JMTR) were performed to get the engineering data for fusion blanket design. This study started as the study on the tritium behavior in beryllium neutron reflector in order to make clear the generation mechanism on tritium of JMTR primary coolant since 1985. These experiences were handed over to beryllium studies for fusion study, and overall studies such as production technology of beryllium pebbles, irradiation behavior evaluation and reprocessing technology have been started since 1990. In this presentation, study on the neutron irradiation behavior of beryllium as the neutron multiplier with JMTR was reviewed from the point of tritium release, thermal properties, mechanical properties and reprocessing technology. (author)

  1. Neutron imaging integrated circuit and method for detecting neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Nagarkar, Vivek V.; More, Mitali J.

    2017-12-05

    The present disclosure provides a neutron imaging detector and a method for detecting neutrons. In one example, a method includes providing a neutron imaging detector including plurality of memory cells and a conversion layer on the memory cells, setting one or more of the memory cells to a first charge state, positioning the neutron imaging detector in a neutron environment for a predetermined time period, and reading a state change at one of the memory cells, and measuring a charge state change at one of the plurality of memory cells from the first charge state to a second charge state less than the first charge state, where the charge state change indicates detection of neutrons at said one of the memory cells.

  2. Point defect dynamics in sodium aluminum hydrides - a combined quasielastic neutron scattering and density functional theory study

    DEFF Research Database (Denmark)

    Shi, Qing; Voss, Johannes; Jacobsen, H.S.

    2007-01-01

    we study hydrogen dynamics in undoped and TiCl3-doped samples of NaAlH4 and Na3AlH6 using a combination of density functional theory calculations and quasielastic neutron scattering. Hydrogen dynamics is found to be limited and mediated by hydrogen vacancies in both alanate phases, requiring...

  3. Neutron polarisers for diffraction experiments

    International Nuclear Information System (INIS)

    Cussen, L.D.; Goossens, D.J.; Hicks, T.J.

    2000-01-01

    Full text: Every neutron in a neutron beam has a spin which is either up or down. In an unpolarised beam, half the neutrons are up and half are down. A neutron polariser is a device which creates an imbalance in the number of up and down spin neutrons in the beam, thus giving a net beam polarisation. The three most common techniques for polarising neutron beams are supermirrors, Heusler alloy polarising monochromators and neutron spin filters. Supermirrors use the difference in refractive index for up and down spin neutrons at a magnetic/non-magnetic interface to selectively remove neutrons of one spin state from the beam. Heusler alloy polarisers give polarised beams through spin dependent Bragg reflection, and transmission filters work by preferentially absorbing the neutrons in one spin state. The most promising filter material is polarised gaseous 3 He, in which the lone neutron is polarised and then the atom will preferentially absorb a neutron of the opposite spin. All three techniques have different advantages. Here, we compare the three techniques by generating quality factors which relate closely to an instruments performance in an experiment and determining which polariser will give the best quality factor for a given type of experiment. We find that supermirrors give the best results when narrow angular divergence of the neutron beam is desired, while filters are best when short wavelengths and wide angular divergence is required. For a powder diffractometer, this implies that a supermirror would be used to polarise the incident beam, while a large array of supermirrors or a single curved transmission filter could be used to analyse the polarisation of the diffracted intensity. We note that while Heusler alloys have advantages in that they combine polarisation with monochromation, on purely performance based criteria, they are not competitive with supermirrors or well-developed transmission filter technology

  4. Lethal action of thermal neutron to living cells

    International Nuclear Information System (INIS)

    Kawai, Kenichi; Akahoshi, Mitsuhiko

    1975-01-01

    Using Amoeba Proteus (DNA content was 5x10 -10 g/cell), action mechanism of thermal neutron was described by using death of cells as an index. Using mononuclear type (M-type) and polynuclear type (P-type) of Amoeba, investigation was made as to whether the number of nucleus contained in cell was related to death of cell by radiation. As compared to gamma-ray, marked difference between sensitivity of both types of Amoeba was not recognized. It was suggested that nucleus was important as a place of death of cell by thermal neutron. In order to demonstrate that reaction of 31 P(n, γ) 32 Pwas a main cause of lethality, the following experiment was carried out. 1) In order to investigate that radical reaction was not a main cause of lethal action by thermal neutron, increase and decrease of radical reaction were observed by adding AET, Cysteine and BudR. As to thermal neutron action, effect of its chemical factors did not appeared. 2) In order to demonstrate that nuclear reaction of constituent atom of living body played an important part in death of cell, increase and decrease of nuclear reaction within cell were observed by taking Na 2 , B 4 and O 7 into Amoeba. It was suggested that nuclear reaction of cell constituent atom itself was important in death of cell. 3) Potentiation effect of gamma-ray and thermal neutron was investigated and its mechanism was discussed. (K. Serizawa)

  5. Fast neutron imaging device and method

    Science.gov (United States)

    Popov, Vladimir; Degtiarenko, Pavel; Musatov, Igor V.

    2014-02-11

    A fast neutron imaging apparatus and method of constructing fast neutron radiography images, the apparatus including a neutron source and a detector that provides event-by-event acquisition of position and energy deposition, and optionally timing and pulse shape for each individual neutron event detected by the detector. The method for constructing fast neutron radiography images utilizes the apparatus of the invention.

  6. Observation of pulsed neutron Ramsey resonance

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, Y. [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba Ibaraki 305-0801 (Japan)]. E-mail: yasuhiro.masuda@kek.jp; Skoy, V. [Joint Institute for Nuclear Reasearch, 141980 Dubna, Moscow Region (Russian Federation); Ino, T. [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba Ibaraki 305-0801 (Japan); Jeong, S.C. [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba Ibaraki 305-0801 (Japan); Watanabe, Y. [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba Ibaraki 305-0801 (Japan)

    2007-07-15

    A Ramsey resonance for pulsed neutrons was observed. The separated oscillatory fields for nuclear magnetic resonance were synchronized with a neutron pulse, and then the Ramsey resonance was observed as a function of the neutron velocity. The phase of one of the oscillatory fields was modulated as a function of the neutron time of flight for a neutron velocity measurement.

  7. Safeguards and Physics Measurements: Neutron Dosimetry

    International Nuclear Information System (INIS)

    Vanhavere, F.

    2000-01-01

    The objective of SCK-CEN's R and D programme on neutron dosimetry is to improve the determination of neutron doses by studying neutron spectra, neutron dosemeters and shielding adaptations as well as to investigate the charcteristics of bubble detectors in order to be able to use them as direct-readiong neutron dosemeters

  8. Structural investigation of viscoelastic micellar water/CTAB/NaNO3 ...

    Indian Academy of Sciences (India)

    celles indicate that addition of NaNO3 leads to a decrease in the surface charge of the ellipsoidal micelles which induces micellar growth. Cryo-TEM measurements support the presence of thread-like micelles in CTAB and NaNO3. Keywords. Worm-like micelles; viscoelasticity; small angle neutron scattering; cryo-. TEM.

  9. High-temperature phases of NaNbO3 and NaTaO3.

    Science.gov (United States)

    Darlington; Knight

    1999-02-01

    The high-temperature phases of the perovskites sodium niobate, NaNbO(3), and sodium tantalate, NaTaO(3), have been re-examined using the high-resolution powder diffractometer HRPD at the ISIS neutron spallation source; the two materials show the same sequence of phases with tilted octahedra. Diffraction patterns were measured every 5 K allowing structural changes with temperature within a single phase to be determined for the first time. Previous structure determinations within one phase had been performed at a single temperature only. The octahedra are tilted about pseudocubic directions and are also deformed; the magnitude of the deformation is shown to be proportional to the square of the angle of tilt as expected from a phenomenological theory applied to such transitions. The structures of NaNbO(3) between 753 and 793 K and of NaTaO(3) below 758 K are not as reported in the literature.

  10. Neutron absorbing article

    International Nuclear Information System (INIS)

    Naum, R.G.; Owens, D.P.; Dooher, G.I.

    1979-01-01

    A neutron absorbing article, in flat plate form and suitable for use in a storage rack for spent fuel, includes boron carbide particles, diluent particles and a solid, irreversibly cured phenolic polymer cured to a continuous matrix binding the boron carbide and diluent particles. The total conent of boron carbide and diluent particles is a major proportion of the article and the content of cured phenolic polymer present is a minor proportion. By regulation of the ratio of boron carbide particles to diluent particles, normally within the range of 1:9 and 9:1 and preferably within the range of 1:5 to 5:1, the neutron absorbing activity of the product may be controlled, which facilitates the manufacture of articles of particular absorbing activities best suitable for specific applications

  11. Neutrons for science

    International Nuclear Information System (INIS)

    Jacrot, B.

    2006-01-01

    In 1967, France and Germany decided to cooperate together for the construction and implementation of a nuclear reactor devoted to research works in physics, chemistry and biology. The Laue-Langevin Institute project was born with the mission of supplying to researchers an intense neutron beam source for the analysis of condensed matter. Great Britain rapidly joined the project, progressively followed by other European countries and making up the Laue-Langevin Institute a successful example of European cooperation. This success demonstrates that such a gathering of forces and competences allow to carry out ambitious projects with the best neutron source in the world. This book tells us the genesis of this project and shows how a suitable organization has permitted to optimize the reactor use. It describes also the portrait of three personalities that have played a key role in this success: J. Horowitz, H. Maier-Leibnitz and L. Neel. (J.S.)

  12. Neutron activation analysis

    International Nuclear Information System (INIS)

    Taure, I.; Riekstina, D.; Veveris, O.

    2004-01-01

    Neutron activation analysis (NAA) in Latvia began to develop after 1961 when nuclear reactor in Salaspils started to work. It provided a powerful neuron source, which is necessary for this analytical method. In 1963 at Institute of Physics of the Latvian Academy of Sciences the Laboratory of Neutron Activation Analysis was formed. At the first stage of development the main tasks were of theoretical and technical aspects of NAA. Later the NAA was used to solve problems in technology, biology, and medicine. In the beginning of the 80-ties more attention was focussed to the use of NAA in the environmental research. Environmental problems stayed the main task till the closing the nuclear reactor in Salaspils in 1998 that ceased the main the existence of the laboratory and of NAA, this significant and powerful analytical method in Latvia and Baltic in general. (authors)

  13. Planets Around Neutron Stars

    Science.gov (United States)

    Wolszczan, Alexander; Kulkarni, Shrinivas R; Anderson, Stuart B.

    2003-01-01

    The objective of this proposal was to continue investigations of neutron star planetary systems in an effort to describe and understand their origin, orbital dynamics, basic physical properties and their relationship to planets around normal stars. This research represents an important element of the process of constraining the physics of planet formation around various types of stars. The research goals of this project included long-term timing measurements of the planets pulsar, PSR B1257+12, to search for more planets around it and to study the dynamics of the whole system, and sensitive searches for millisecond pulsars to detect further examples of old, rapidly spinning neutron stars with planetary systems. The instrumentation used in our project included the 305-m Arecibo antenna with the Penn State Pulsar Machine (PSPM), the 100-m Green Bank Telescope with the Berkeley- Caltech Pulsar Machine (BCPM), and the 100-m Effelsberg and 64-m Parkes telescopes equipped with the observatory supplied backend hardware.

  14. FAST NEUTRON SPECTROMETER

    Science.gov (United States)

    Davis, F.J.; Hurst, G.S.; Reinhardt, P.W.

    1959-08-18

    An improved proton recoil spectrometer for determining the energy spectrum of a fast neutron beam is described. Instead of discriminating against and thereby"throwing away" the many recoil protons other than those traveling parallel to the neutron beam axis as do conventional spectrometers, this device utilizes protons scattered over a very wide solid angle. An ovoidal gas-filled recoil chamber is coated on the inside with a scintillator. The ovoidal shape of the sensitive portion of the wall defining the chamber conforms to the envelope of the range of the proton recoils from the radiator disposed within the chamber. A photomultiplier monitors the output of the scintillator, and a counter counts the pulses caused by protons of energy just sufficient to reach the scintillator.

  15. Neutron beam measurement dosimetry

    International Nuclear Information System (INIS)

    Amaro, C.R.

    1995-01-01

    This report describes animal dosimetry studies and phantom measurements. During 1994, 12 dogs were irradiated at BMRR as part of a 4 fraction dose tolerance study. The animals were first infused with BSH and irradiated daily for 4 consecutive days. BNL irradiated 2 beagles as part of their dose tolerance study using BPA fructose. In addition, a dog at WSU was irradiated at BMRR after an infusion of BPA fructose. During 1994, the INEL BNCT dosimetry team measured neutron flux and gamma dose profiles in two phantoms exposed to the epithermal neutron beam at the BMRR. These measurements were performed as a preparatory step to the commencement of human clinical trials in progress at the BMRR

  16. Structure of neutron stars

    International Nuclear Information System (INIS)

    Cheong, C.K.

    1974-01-01

    Structure of neutron stars consisting of a cold and catalyzed superdense matter were investigated by integrating the equations for hydrostatic equilibrium based on the General Relativity theory. The equations of state were obtained with the help of semiempirical nuclear mass formulae. A large phase transition was found between the nuclear and subnuclear density regions. The density phase transition points were calculated as 6.2 x 10 11 and 3.8 x 10 13 g/cm 3 . Due to such a large phase transition, the equation of state practically consists of two parts: The nuclear and subnuclear phases wich are in contact under the thermodynamical equilibrium at the corresponding pressure. Some macroscopic properties of neutron stars are discussed. (Author) [pt

  17. Short pulse neutron generator

    Science.gov (United States)

    Elizondo-Decanini, Juan M.

    2016-08-02

    Short pulse neutron generators are described herein. In a general embodiment, the short pulse neutron generator includes a Blumlein structure. The Blumlein structure includes a first conductive plate, a second conductive plate, a third conductive plate, at least one of an inductor or a resistor, a switch, and a dielectric material. The first conductive plate is positioned relative to the second conductive plate such that a gap separates these plates. A vacuum chamber is positioned in the gap, and an ion source is positioned to emit ions in the vacuum chamber. The third conductive plate is electrically grounded, and the switch is operable to electrically connect and disconnect the second conductive plate and the third conductive plate. The at least one of the resistor or the inductor is coupled to the first conductive plate and the second conductive plate.

  18. Hyper-thermal neutron irradiation field for neutron capture therapy

    International Nuclear Information System (INIS)

    Sakurai, Yoshinori; Kobayashi, Tooru; Kanda, Keiji

    1994-01-01

    The utilization of hyper-thermal neutrons, which have an energy spectrum of a Maxwell distribution higher than the room temperature of 300 K, has been studied in order to improve the thermal neutron flux distribution in a living body for a deep-seated tumor in neutron capture therapy (NCT). Simulation calculations using MCNP-V3 were carried out in order to investigate the characteristics of the hyper-thermal neutron irradiation field. From the results of simulation calculations, the following were confirmed: (i) The irradiation field of the hyper-thermal neutrons is feasible by using some scattering materials with high temperature, such as Be, BeO, C, SiC and ZrH 1.7 . Especially, ZrH 1.7 is thought to be the best material because of good characteristics of up-scattering for thermal neutrons. (ii) The ZrH 1.7 of 1200 K yields the hyper-thermal neutrons of a Maxwell-like distribution at about 2000 K and the treatable depth is about 1.5 cm larger comparing with the irradiation of the thermal neutrons of 300 K. (iii) The contamination by the secondary gamma-rays from the scattering materials can be sufficiently eliminated to the tolerance level for NCT through the bismuth layer, without the larger change of the energy spectrum of hyper-thermal neutrons. ((orig.))

  19. Correlation properties of delayed neutrons from fast neutron induced fission

    International Nuclear Information System (INIS)

    Piksaikin, V.M.; Isaev, S.G.

    1998-01-01

    The experimental studies of the energy dependence of the delayed neutron parameters for various fissioning systems has shown that the behavior of a some combination of delayed neutron parameters (group relative abundances a i and half lives T i ) has a similar features. On the basis of this findings the systematics of delayed neutron experimental data for thorium, uranium, plutonium and americium isotopes have been investigated with the purpose to find a correlation of DN parameters with characteristics of fissioning system as well as a correlation between the delayed neutron parameters themselves. Below we will present the preliminary results which were obtained during this study omitting the physics interpretation of the results. (author)

  20. Neutron stress measurement using neutron image plate. 4

    International Nuclear Information System (INIS)

    Sasaki, Toshihiko; Hirose, Yukio; Minakawa, Noriaki; Morii, Yukio; Niimura, Nobuo

    2001-01-01

    A fundamental study on the neutron stress measurement using an image plate neutron detector was described. First, a method for determining internal mean stress over the area where incident beams pass through was explained. The method is based on the α angle method by which the stress analysis is conducted using information along a diffraction ring. Second, a neutron diffraction experiment was shown. This was conducted using the research reactor, JRR-3M, at Japan Atomic Energy Research Institute (JAERI). The 211 diffraction rings from steel sample were obtained using the image plate neutron detector. It was found that the mean stress obtained by the image plate agreed with stress applied. (author)