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Sample records for neutrons instrumental para

  1. Neutron instrumentation for biology

    Energy Technology Data Exchange (ETDEWEB)

    Mason, S.A. [Institut Laue-Langevin, Grenoble (France)

    1994-12-31

    In the October 1994 round of proposals at the ILL, the external biology review sub- committee was asked to allocate neutron beam time to a wide range of experiments, on almost half the total number of scheduled neutron instruments: on 3 diffractometers, on 3 small angle scattering instruments, and on some 6 inelastic scattering spectrometers. In the 3.5 years since the temporary reactor shutdown, the ILL`s management structure has been optimized, budgets and staff have been trimmed, the ILL reactor has been re-built, and many of the instruments up-graded, many powerful (mainly Unix) workstations have been introduced, and the neighboring European Synchrotron Radiation Facility has established itself as the leading synchrotron radiation source and has started its official user program. The ILL reactor remains the world`s most intense dedicated neutron source. In this challenging context, it is of interest to review briefly the park of ILL instruments used to study the structure and energetics of small and large biological systems. A brief summary will be made of each class of experiments actually proposed in the latest ILL proposal round.

  2. Instruments and accessories for neutron scattering research

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Yoshinobu; Morii, Yukio [eds.] [Advanced Science Research Center (Tokai Site), Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan)

    2000-04-01

    This report describes neutron scattering instruments and accessories installed by four neutron scattering research groups at the ASRC (Advanced Science Research Center) of the JAERI and the recent topics of neutron scattering research using these instruments. The specifications of nine instruments (HRPD, BIX-I, TAS-1 and PNO in the reactor hall, RESA, BIX-II, TAS-2, LTAS and SANS-J in the guide hall of the JRR-3M) are summarized in this booklet. (author)

  3. Development of pulsed neutron uranium logging instrument

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin-guang, E-mail: wangxg@upc.edu.cn [School of Geosciences, China University of Petroleum, Qingdao 266580 (China); Engineering Research Center of Nuclear Technology Application (East China Institute of Technology), Ministry of Education, Nanchang 330013 (China); Liu, Dan [China Institute of Atomic Energy, Beijing 102413 (China); Zhang, Feng [School of Geosciences, China University of Petroleum, Qingdao 266580 (China)

    2015-03-15

    This article introduces a development of pulsed neutron uranium logging instrument. By analyzing the temporal distribution of epithermal neutrons generated from the thermal fission of {sup 235}U, we propose a new method with a uranium-bearing index to calculate the uranium content in the formation. An instrument employing a D-T neutron generator and two epithermal neutron detectors has been developed. The logging response is studied using Monte Carlo simulation and experiments in calibration wells. The simulation and experimental results show that the uranium-bearing index is linearly correlated with the uranium content, and the porosity and thermal neutron lifetime of the formation can be acquired simultaneously.

  4. Neutron scattering instruments for the Spallation Neutron Source (SNS)

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, R.K.; Fornek, T. [Argonne National Lab., IL (United States); Herwig, K.W. [Oak Ridge National Lab., TN (United States)

    1998-07-01

    The Spallation Neutron Source (SNS) is a 1 MW pulsed spallation source for neutron scattering planned for construction at Oak Ridge National Laboratory. This facility is being designed as a 5-laboratory collaboration project. This paper addresses the proposed facility layout, the process for selection and construction of neutron scattering instruments at the SNS, the initial planning done on the basis of a reference set of ten instruments, and the plans for research and development (R and D) to support construction of the first ten instruments and to establish the infrastructure to support later development and construction of additional instruments.

  5. The neutron instrument simulation package, NISP

    Science.gov (United States)

    Seeger, Philip A.; Daemen, Luke L.

    2004-10-01

    The Neutron Instrument Simulation Package (NISP) performs complete source-to-detector simulations of neutron instruments, including neutrons that do not follow the expected path. The original user interface (MC_Web) is a web-based application, http://strider.lansce.lanl.gov/NISP/Welcome.html. This report describes in detail the newer stand-alone Windows version, NISP_Win. Instruments are assembled from menu-selected elements, including neutron sources, collimation and transport elements, samples, analyzers, and detectors. Magnetic field regions may also be specified for the propagation of polarized neutrons including spin precession. Either interface writes a geometry file that is used as input to the Monte Carlo engine (MC_Run) in the user's computer. Both the interface and the engine rely on a subroutine library, MCLIB. The package is completely open source. New features include capillary optics, temperature dependence of Al and Be, revised source files for ISIS, and visualization of neutron trajectories at run time. Also, a single-crystal sample type has been successfully imported from McStas (with more generalized geometry), demonstrating the capability of including algorithms from other sources, and NISP_Win may render the instrument in a virtual reality file. Results are shown for two instruments under development.

  6. The neutron instrument simulation package, NISP.

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, P. A. (Philip A.); Daemen, L. L. (Luc L.)

    2004-01-01

    The Neutron Instrument Simulation Package (NISP) performs complete source-to-detector simulations of neutron instruments, including neutrons that do not follow the expected path. The original user interface (MC{_}Web) is a web-based application, http://strider.lansce.lanl.gov/NISP/Welcome.html. This report describes in detail the newer standalone Windows version, NISP{_}Win. Instruments are assembled from menu-selected elements, including neutron sources, collimation and transport elements, samples, analyzers, and detectors. Magnetic field regions may also be specified for the propagation of polarized neutrons including spin precession. Either interface writes a geometry file that is used as input to the Monte Carlo engine (MC{_}Run) in the user's computer. Both the interface and the engine rely on a subroutine library, MCLIB. The package is completely open source. New features include capillary optics, temperature dependence of Al and Be, revised source files for ISIS, and visualization of neutron trajectories at run time. Also, a single-crystal sample type has been successfully imported from McStas (with more generalized geometry), demonstrating the capability of including algorithms from other sources, and NISP{_}Win may render the instrument in a virtual reality file. Results are shown for two instruments under development.

  7. Monte Carlo simulation of neutron scattering instruments

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, P.A.

    1995-12-31

    A library of Monte Carlo subroutines has been developed for the purpose of design of neutron scattering instruments. Using small-angle scattering as an example, the philosophy and structure of the library are described and the programs are used to compare instruments at continuous wave (CW) and long-pulse spallation source (LPSS) neutron facilities. The Monte Carlo results give a count-rate gain of a factor between 2 and 4 using time-of-flight analysis. This is comparable to scaling arguments based on the ratio of wavelength bandwidth to resolution width.

  8. Neutron Instrumentation and Neutron Investigation of Archaeometallurgical Arms and Armours

    DEFF Research Database (Denmark)

    Fedrigo, Anna

    Neutron scattering, once a technique that was the preserve of physics and chemistry, has grown to be applied in a much broader range of fields, spanning engineering, archaeology, life-science, and sustainable-energy applications. The present work focuses on two topics: first, the instrument desig...

  9. Evolutionary programming for neutron instrument optimisation

    Science.gov (United States)

    Bentley, Phillip M.; Pappas, Catherine; Habicht, Klaus; Lelièvre-Berna, Eddy

    2006-11-01

    Virtual instruments based on Monte-Carlo techniques are now integral part of novel instrumentation development and the existing codes (McSTAS and Vitess) are extensively used to define and optimise novel instrumental concepts. Neutron spectrometers, however, involve a large number of parameters and their optimisation is often a complex and tedious procedure. Artificial intelligence algorithms are proving increasingly useful in such situations. Here, we present an automatic, reliable and scalable numerical optimisation concept based on the canonical genetic algorithm (GA). The algorithm was used to optimise the 3D magnetic field profile of the NSE spectrometer SPAN, at the HMI. We discuss the potential of the GA which combined with the existing Monte-Carlo codes (Vitess, McSTAS, etc.) leads to a very powerful tool for automated global optimisation of a general neutron scattering instrument, avoiding local optimum configurations.

  10. Evolutionary programming for neutron instrument optimisation

    Energy Technology Data Exchange (ETDEWEB)

    Bentley, Phillip M. [Hahn-Meitner Institut, Glienicker Strasse 100, D-14109 Berlin (Germany)]. E-mail: phillip.bentley@hmi.de; Pappas, Catherine [Hahn-Meitner Institut, Glienicker Strasse 100, D-14109 Berlin (Germany); Habicht, Klaus [Hahn-Meitner Institut, Glienicker Strasse 100, D-14109 Berlin (Germany); Lelievre-Berna, Eddy [Institut Laue-Langevin, 6 rue Jules Horowitz, BP 156, 38042 Grenoble Cedex 9 (France)

    2006-11-15

    Virtual instruments based on Monte-Carlo techniques are now integral part of novel instrumentation development and the existing codes (McSTAS and Vitess) are extensively used to define and optimise novel instrumental concepts. Neutron spectrometers, however, involve a large number of parameters and their optimisation is often a complex and tedious procedure. Artificial intelligence algorithms are proving increasingly useful in such situations. Here, we present an automatic, reliable and scalable numerical optimisation concept based on the canonical genetic algorithm (GA). The algorithm was used to optimise the 3D magnetic field profile of the NSE spectrometer SPAN, at the HMI. We discuss the potential of the GA which combined with the existing Monte-Carlo codes (Vitess, McSTAS, etc.) leads to a very powerful tool for automated global optimisation of a general neutron scattering instrument, avoiding local optimum configurations.

  11. Instrumentation of a manually programmed neutron diffractometer

    DEFF Research Database (Denmark)

    Hansen, K.B.; Neisig, K.E.

    1966-01-01

    This paper describes essentially the digital part of the instrumentation for a neutron diffractometer in which the measuring procedure is governed by a control unit involving a fixed number of program points. A simultaneously running test program monitors the information transfer from the data...

  12. Monte Carlo simulation of neutron scattering instruments

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, P.A.; Daemen, L.L.; Hjelm, R.P. Jr.

    1998-12-01

    A code package consisting of the Monte Carlo Library MCLIB, the executing code MC{_}RUN, the web application MC{_}Web, and various ancillary codes is proposed as an open standard for simulation of neutron scattering instruments. The architecture of the package includes structures to define surfaces, regions, and optical elements contained in regions. A particle is defined by its vector position and velocity, its time of flight, its mass and charge, and a polarization vector. The MC{_}RUN code handles neutron transport and bookkeeping, while the action on the neutron within any region is computed using algorithms that may be deterministic, probabilistic, or a combination. Complete versatility is possible because the existing library may be supplemented by any procedures a user is able to code. Some examples are shown.

  13. Neutron tomography instrument CONRAD at HZB

    Energy Technology Data Exchange (ETDEWEB)

    Kardjilov, N., E-mail: kardjilov@helmholtz-berlin.de [Helmholtz Centre Berlin, Hahn-Meitner Pl. 1, 14109 Berlin (Germany); Hilger, A.; Manke, I.; Strobl, M. [Helmholtz Centre Berlin, Hahn-Meitner Pl. 1, 14109 Berlin (Germany); Dawson, M. [Helmholtz Centre Berlin, Hahn-Meitner Pl. 1, 14109 Berlin (Germany); University of Salford, Salford M5 4WT (United Kingdom); Williams, S.; Banhart, J. [Helmholtz Centre Berlin, Hahn-Meitner Pl. 1, 14109 Berlin (Germany)

    2011-09-21

    The neutron tomography instrument CONRAD has been in operation since 2005 at the Hahn-Meitner research reactor at Helmholtz-Zentrum Berlin (HZB). Over the last 5 years, significant developmental work has been performed to expand the radiographic and tomographic capabilities of the beamline . New techniques have been implemented, including imaging with polarized neutrons , Bragg-edge mapping , high-resolution neutron imaging and grating interferometry . These methods have been provided to the user community as tools to help address scientific problems over a broad range of topics such as superconductivity, materials research, life sciences , cultural heritage and paleontology . Industrial applications including fuel cell research have also been improved through these new developments. Descriptions and parameters of the developed options will be presented, along with prominent examples.

  14. Neutron scattering instrumentation for biology at spallation neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Pynn, R. [Los Alamos National Laboratory, NM (United States)

    1994-12-31

    Conventional wisdom holds that since biological entities are large, they must be studied with cold neutrons, a domain in which reactor sources of neutrons are often supposed to be pre-eminent. In fact, the current generation of pulsed spallation neutron sources, such as LANSCE at Los Alamos and ISIS in the United Kingdom, has demonstrated a capability for small angle scattering (SANS) - a typical cold- neutron application - that was not anticipated five years ago. Although no one has yet built a Laue diffractometer at a pulsed spallation source, calculations show that such an instrument would provide an exceptional capability for protein crystallography at one of the existing high-power spoliation sources. Even more exciting is the prospect of installing such spectrometers either at a next-generation, short-pulse spallation source or at a long-pulse spallation source. A recent Los Alamos study has shown that a one-megawatt, short-pulse source, which is an order of magnitude more powerful than LANSCE, could be built with today`s technology. In Europe, a preconceptual design study for a five-megawatt source is under way. Although such short-pulse sources are likely to be the wave of the future, they may not be necessary for some applications - such as Laue diffraction - which can be performed very well at a long-pulse spoliation source. Recently, it has been argued by Mezei that a facility that combines a short-pulse spallation source similar to LANSCE, with a one-megawatt, long-pulse spallation source would provide a cost-effective solution to the global shortage of neutrons for research. The basis for this assertion as well as the performance of some existing neutron spectrometers at short-pulse sources will be examined in this presentation.

  15. New sources and instrumentation for neutrons in biology

    DEFF Research Database (Denmark)

    Teixeira, S. C. M.; Zaccai, G.; Ankner, J.

    2008-01-01

    Neutron radiation offers significant advantages for the study of biological molecular structure and dynamics. A broad and significant effort towards instrumental and methodological development to facilitate biology experiments at neutron sources worldwide is reviewed.......Neutron radiation offers significant advantages for the study of biological molecular structure and dynamics. A broad and significant effort towards instrumental and methodological development to facilitate biology experiments at neutron sources worldwide is reviewed....

  16. New sources and instrumentation for neutrons in biology

    DEFF Research Database (Denmark)

    Teixeira, S. C. M.; Zaccai, G.; Ankner, J.;

    2008-01-01

    Neutron radiation offers significant advantages for the study of biological molecular structure and dynamics. A broad and significant effort towards instrumental and methodological development to facilitate biology experiments at neutron sources worldwide is reviewed.......Neutron radiation offers significant advantages for the study of biological molecular structure and dynamics. A broad and significant effort towards instrumental and methodological development to facilitate biology experiments at neutron sources worldwide is reviewed....

  17. Status of the Neutron Imaging and Diffraction Instrument IMAT

    Science.gov (United States)

    Kockelmann, Winfried; Burca, Genoveva; Kelleher, Joe F.; Kabra, Saurabh; Zhang, Shu-Yan; Rhodes, Nigel J.; Schooneveld, Erik M.; Sykora, Jeff; Pooley, Daniel E.; Nightingale, Jim B.; Aliotta, Francesco; Ponterio, Rosa C.; Salvato, Gabriele; Tresoldi, Dario; Vasi, Cirino; McPhate, Jason B.; Tremsin, Anton S.

    A cold neutron imaging and diffraction instrument, IMAT, is currently being constructed at the ISIS second target station. IMAT will capitalize on time-of-flight transmission and diffraction techniques available at a pulsed neutron source. Analytical techniques will include neutron radiography, neutron tomography, energy-selective neutron imaging, and spatially resolved diffraction scans for residual strain and texture determination. Commissioning of the instrument will start in 2015, with time-resolving imaging detectors and two diffraction detector prototype modules. IMAT will be operated as a user facility for material science applications and will be open for developments of time-of-flight imaging methods.

  18. Neutron Scattering Investigations of Correlated Electron Systems and Neutron Instrumentation

    DEFF Research Database (Denmark)

    Holm, Sonja Lindahl

    are a unique probe for studying the atomic and molecular structure and dynamics of materials. Even though neutrons are very expensive to produce, the advantages neutrons provide overshadow the price. As neutrons interact weakly with materials compared to many other probes, e.g. electrons or photons......, it is possible to make a neutron scattering experiment through sample environment equipment like cryostats or pressure cells. Another advantage of neutron experiments is that the wavelength and energy of the neutron match the inter-atomic distances and basic excitations of solid materials. The scattering cross...... is not taken into account in previous reports on the field effect of magnetic scattering, since usually only L 0 is probed. A paper draft submitted for publication describing the results of elastic and inelastic neutron scattering experiments performed on the oxygen-doped La2CuO4+y HTSC is appended (Tc 40 K...

  19. Monte-Carlo Simulation on Neutron Instruments at CARR

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The design of high resolution neutron powder diffractometer(HRPD) and two cold neutron guides(CNGs) to be built at China advanced research reactor(CARR) are studied by Monte-Carlo simulation technique.The HRPD instrument is desiged to have a minimum resolution of 0.2% and neutron fluence rate of greater than 106 cm-2 ·s-1 at sample position. The resolution curves, neutron fluence rate and effective neutron beam size at sample position are given. Differences in resolutions and intensity between the

  20. Neutron Scattering Investigations of Correlated Electron Systems and Neutron Instrumentation

    DEFF Research Database (Denmark)

    Holm, Sonja Lindahl

    are a unique probe for studying the atomic and molecular structure and dynamics of materials. Even though neutrons are very expensive to produce, the advantages neutrons provide overshadow the price. As neutrons interact weakly with materials compared to many other probes, e.g. electrons or photons......, it is possible to make a neutron scattering experiment through sample environment equipment like cryostats or pressure cells. Another advantage of neutron experiments is that the wavelength and energy of the neutron match the inter-atomic distances and basic excitations of solid materials. The scattering cross...... magnetism. This is in contrast to what is observed as the critical temperature is slightly lower for this system compared to other co-doped systems, suggesting that the magnetic and superconducting phases co-exist. A published manuscript describes the study of magnetic and superconducting properties of Ba...

  1. Design Analyses and Shielding of HFIR Cold Neutron Scattering Instruments

    Energy Technology Data Exchange (ETDEWEB)

    Gallmeier, F.X.; Selby, D.L.; Winn, B.; Stoica, D.; Jones, A.B.; Crow, L. [Neutron Sciences Directorate, Oak Ridge National Laboratory (United States)

    2011-07-01

    Research reactor geometries and special characteristics present unique dosimetry analysis and measurement issues. The introduction of a cold neutron moderator and the production of cold neutron beams at the Oak Ridge National Laboratory High Flux Isotope Reactor have created the need for modified methods and devices for analyzing and measuring low energy neutron fields (0.01 to 100 meV). These methods include modifications to an MCNPX version to provide modeling of neutron mirror reflection capability. This code has been used to analyze the HFIR cold neutron beams and to design new instrument equipment that will use the beams. Calculations have been compared with time-of-flight measurements performed at the start of the neutron guides and at the end of one of the guides. The results indicate that we have a good tool for analyzing the transport of these low energy beams through neutron mirror and guide systems for distance up to 60 meters from the reactor. (authors)

  2. Quantifying the information measured by neutron scattering instruments

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, M.W. [Rutherford Appleton Lab., Oxon (United Kingdom)

    1997-09-01

    The concept of the information content of a scientific measurement is introduced, and a theory is presented which enables the information that may be obtained by a neutron scattering instrument to be calculated. When combined with the time taken to perform the measurement the bandwidth of the instrument is obtained. This bandwidth is effectively a figure of merit which is of use in three respects: in the design of neutron instrumentation, the optimisation of measurements, and in the comparison of one instrument with another.

  3. Current status of some neutron instruments in Serpong

    Energy Technology Data Exchange (ETDEWEB)

    Ikram, A.; Hardi, T.; Maulana, A. [Neutron Scattering Lab., Materials Science Research Center, BATAN-Serpong, Jakarta (Indonesia)

    1998-10-01

    Performances of the Small Angle Neutron Scattering Spectrometer, the High Resolution Small Angle Neutron Scattering Spectrometer and the High Resolution Neutron Powder Diffractometer in the last full one year are presented as well as problems, difficulties and limitations faced by each instrument. Efforts that have been done to overcome those shortcomings are also mentioned. Proposed collaboration in order to bring those instruments back to a state that can perform scientifically acceptable is described to a level that can be agreed in this workshop. (author)

  4. Neutron Scattering Collimation Wheel Instrument for Imaging Research

    Science.gov (United States)

    Van Every, E.; Deyhim, A.

    2016-09-01

    The design of a state-of-the-art selector wheel instrument to support the area of neutron imaging research (neutron radiography/ tomography) is discussed. The selector wheel is installed on the DINGO Radiography instrument at the Bragg Institute HB2 beamline at ANSTO in Sidney Aus. The selector wheel consists of a single axis drum filled with a wax/steel shielding mixture and six square cutouts for neutron optics and a larger solid shielding sector to act as a shutter. This paper focuses on the details of design and shielding of the selector wheel.

  5. Data acquisition system for the neutron scattering instruments at the intense pulsed neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, R.K.; Daly, R.T.; Haumann, J.R.; Hitterman, R.L.; Morgan, C.B.; Ostrowski, G.E.; Worlton, T.G.

    1981-01-01

    The Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory is a major new user-oriented facility which is now coming on line for basic research in neutron scattering and neutron radiation damage. This paper describes the data-acquisition system which will handle data acquisition and instrument control for the time-of-flight neutron-scattering instruments at IPNS. This discussion covers the scientific and operational requirements for this system, and the system architecture that was chosen to satisfy these requirements. It also provides an overview of the current system implementation including brief descriptions of the hardware and software which have been developed.

  6. Planetary Geochemistry Using Active Neutron and Gamma Ray Instrumentation

    Science.gov (United States)

    Parsons, A.; Bodnarik, J.; Evans, L.; Floyd, S.; Lim, L.; McClanahan, T.; Namkung, M.; Schweitzer, J.; Starr, R.; Trombka, J.

    2010-01-01

    The Pulsed Neutron Generator-Gamma Ray And Neutron Detector (PNG-GRAND) experiment is an innovative application of the active neutron-gamma ray technology so successfully used in oil field well logging and mineral exploration on Earth, The objective of our active neutron-gamma ray technology program at NASA Goddard Space Flight Center (NASA/GSFC) is to bring the PNG-GRAND instrument to the point where it can be flown on a variety of surface lander or rover missions to the Moon, Mars, Venus, asterOIds, comets and the satellites of the outer planets, Gamma-Ray Spectrometers have been incorporated into numerous orbital planetary science missions and, especially in the case of Mars Odyssey, have contributed detailed maps of the elemental composition over the entire surface of Mars, Neutron detectors have also been placed onboard orbital missions such as the Lunar Reconnaissance Orbiter and Lunar Prospector to measure the hydrogen content of the surface of the moon, The DAN in situ experiment on the Mars Science Laboratory not only includes neutron detectors, but also has its own neutron generator, However, no one has ever combined the three into one instrument PNG-GRAND combines a pulsed neutron generator (PNG) with gamma ray and neutron detectors to produce a landed instrument that can determine subsurface elemental composition without drilling. We are testing PNG-GRAND at a unique outdoor neutron instrumentation test facility recently constructed at NASA/GSFC that consists of a 2 m x 2 m x 1 m granite structure in an empty field, We will present data from the operation of PNG-GRAND in various experimental configurations on a known sample in a geometry that is identical to that which can be achieved on a planetary surface. We will also compare the material composition results inferred from our experiments to both an independent laboratory elemental composition analysis and MCNPX computer modeling results,

  7. Intercomparison of radiation protection instrumentation in a pulsed neutron field

    Energy Technology Data Exchange (ETDEWEB)

    Caresana, M., E-mail: marco.caresana@polimi.it [Politecnico di Milano, CESNEF, Dipartimento di Energia, via Ponzio 34/3, 20133 Milano (Italy); Denker, A. [Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Esposito, A. [IFNF-LNF, FISMEL, via E. Fermi 40, 00044 Frascati (Italy); Ferrarini, M. [CNAO, Via Privata Campeggi, 27100 Pavia (Italy); Golnik, N. [Institute of Metrology and Biomedical Engineering, Warsaw University of Technology, Sw. A. Boboli 8, 02-525 Warsaw (Poland); Hohmann, E. [Paul Scherrer Institut (PSI), Radiation Metrology Section, CH-5232 Villigen PSI (Switzerland); Leuschner, A. [Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22603 Hamburg (Germany); Luszik-Bhadra, M. [Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig (Germany); Manessi, G. [CERN, 1211 Geneva 23 (Switzerland); University of Liverpool, Department of Physics, L69 7ZE Liverpool (United Kingdom); Mayer, S. [Paul Scherrer Institut (PSI), Radiation Metrology Section, CH-5232 Villigen PSI (Switzerland); Ott, K. [Helmholtz-Zentrum Berlin, BESSYII, Albert-Einstein-Str.15, 12489 Berlin (Germany); Röhrich, J. [Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Silari, M. [CERN, 1211 Geneva 23 (Switzerland); Trompier, F. [Institute for Radiological Protection and Nuclear Safety, F-92262 Fontenay aux Roses (France); Volnhals, M.; Wielunski, M. [Helmholtz Zentrum München, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany)

    2014-02-11

    In the framework of the EURADOS working group 11, an intercomparison of active neutron survey meters was performed in a pulsed neutron field (PNF). The aim of the exercise was to evaluate the performances of various neutron instruments, including commercially available rem-counters, personal dosemeters and instrument prototypes. The measurements took place at the cyclotron of the Helmholtz-Zentrum Berlin für Materialien und Energie GmbH. The cyclotron is routinely used for proton therapy of ocular tumours, but an experimental area is also available. For the therapy the machine accelerates protons to 68 MeV. The interaction of the proton beam with a thick tungsten target produces a neutron field with energy up to about 60 MeV. One interesting feature of the cyclotron is that the beam can be delivered in bursts, with the possibility to modify in a simple and flexible way the burst length and the ion current. Through this possibility one can obtain radiation bursts of variable duration and intensity. All instruments were placed in a reference position and irradiated with neutrons delivered in bursts of different intensity. The analysis of the instrument response as a function of the burst charge (the total electric charge of the protons in the burst shot onto the tungsten target) permitted to assess for each device the dose underestimation due to the time structure of the radiation field. The personal neutron dosemeters were exposed on a standard PMMA slab phantom and the response linearity was evaluated.

  8. Modularized Parallel Neutron Instrument Simulation on the TeraGrid

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Meili [ORNL; Cobb, John W [ORNL; Hagen, Mark E [ORNL; Miller, Stephen D [ORNL; Lynch, Vickie E [ORNL

    2007-01-01

    In order to build a bridge between the TeraGrid (TG), a national scale cyberinfrastructure resource, and neutron science, the Neutron Science TeraGrid Gateway (NSTG) is focused on introducing productive HPC usage to the neutron science community, primarily the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). Monte Carlo simulations are used as a powerful tool for instrument design and optimization at SNS. One of the successful efforts of a collaboration team composed of NSTG HPC experts and SNS instrument scientists is the development of a software facility named PSoNI, Parallelizing Simulations of Neutron Instruments. Parallelizing the traditional serial instrument simulation on TeraGrid resources, PSoNI quickly computes full instrument simulation at sufficient statistical levels in instrument de-sign. Upon SNS successful commissioning, to the end of 2007, three out of five commissioned instruments in SNS target station will be available for initial users. Advanced instrument study, proposal feasibility evalua-tion, and experiment planning are on the immediate schedule of SNS, which pose further requirements such as flexibility and high runtime efficiency on fast instrument simulation. PSoNI has been redesigned to meet the new challenges and a preliminary version is developed on TeraGrid. This paper explores the motivation and goals of the new design, and the improved software structure. Further, it describes the realized new fea-tures seen from MPI parallelized McStas running high resolution design simulations of the SEQUOIA and BSS instruments at SNS. A discussion regarding future work, which is targeted to do fast simulation for automated experiment adjustment and comparing models to data in analysis, is also presented.

  9. Instrumentation to handle thermal polarized neutron beams

    NARCIS (Netherlands)

    Kraan, W.H.

    2004-01-01

    In this thesis we investigate devices needed to handle the polarization of thermal neutron beams: Ï/2-flippers (to start/stop Larmor precession) and Ï-flippers (to reverse polarization/precession direction) and illustrate how these devices are used to investigate the properties of matter and of the

  10. Methods and Instruments for Fast Neutron Detection

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, David V.; Reeder, Paul L.; Cooper, Matthew W.; McCormick, Kathleen R.; Peurrung, Anthony J.; Warren, Glen A.

    2005-05-01

    Pacific Northwest National Laboratory evaluated the performance of a large-area (~0.7 m2) plastic scintillator time-of-flight (TOF) sensor for direct detection of fast neutrons. This type of sensor is a readily area-scalable technology that provides broad-area geometrical coverage at a reasonably low cost. It can yield intrinsic detection efficiencies that compare favorably with moderator-based detection methods. The timing resolution achievable should permit substantially more precise time windowing of return neutron flux than would otherwise be possible with moderated detectors. The energy-deposition threshold imposed on each scintillator contributing to the event-definition trigger in a TOF system can be set to blind the sensor to direct emission from the neutron generator. The primary technical challenge addressed in the project was to understand the capabilities of a neutron TOF sensor in the limit of large scintillator area and small scintillator separation, a size regime in which the neutral particle’s flight path between the two scintillators is not tightly constrained.

  11. Neutron Instrumentation and Neutron Investigation of Archaeometallurgical Arms and Armours

    DEFF Research Database (Denmark)

    Fedrigo, Anna

    and a system of optical blind choppers, which make it possible to trade flux for energy resolution. The application of neutron diffraction and imaging techniques have long demonstrated their potential in the characterisation of dense materials in engineering and material science. In this project they have been...... used as a non-destructive analytical tool for the study of metallic artefacts of archaeometric interest. Three “pattern-welded” sword blades from the Viking age, provided by the National Museum of Denmark, have been fully characterised in terms of composition, manufacturing processes, and conservation...

  12. Neutrons and music: Imaging investigation of ancient wind musical instruments

    Science.gov (United States)

    Festa, G.; Tardino, G.; Pontecorvo, L.; Mannes, D. C.; Senesi, R.; Gorini, G.; Andreani, C.

    2014-10-01

    A set of seven musical instruments and two instruments cares from the 'Fondo Antico della Biblioteca del Sacro Convento' in Assisi, Italy, were investigated through neutron and X-ray imaging techniques. Historical and scientific interests around ancient musical instruments motivate an intense research effort for their characterization using non-destructive and non-invasive techniques. X-ray and neutron tomography/radiography were applied to the study of composite material samples containing wood, hide and metals. The study was carried out at the NEUTRA beamline, PSI (Paul Scherrer Institute, Switzerland). Results of the measurements provided new information on the composite and multi-scale structure, such as: the internal structure of the samples, position of added materials like metals, wood fiber displays, deformations, presence of adhesives and their spatial distribution and novel insight about construction methods to guide the instruments' restoration process.

  13. Instrumentation To Handle Thermal-polarized Neutron Beams

    CERN Document Server

    Kraan, W H

    2004-01-01

    In this thesis we investigate devices needed to handle the polarization of thermal neutron beams: π/2- flippers (to start/stop Larmor precession) and π- flippers (to reverse polarization/ precession direction) and illustrate how these devices are used to investigate the properties of matter and of the neutron. The central theme is: demonstration—for the full thermal spectrum—of a special mode of Larmor precession (called “zero-field”-precession) over the neutron beam path length between two “adiabatic Radio-Frequency flippers”. This technique enables one to build neutron spin-echo spectrometers with exceedingly large precession angles, without applying magnetic fields over long distances (meters). As an extension of this demonstration, a prototype S&barbelow;pin-E&barbelow;cho instrument for S&barbelow;mall A&barbelow;ngle N&barbelow;eutron S&barbelow;cattering (SESANS) was built, based on similar flippers with s...

  14. Coherence approach to neutron polarization propagation in instruments

    NARCIS (Netherlands)

    De Haan, V.O.; Van Well, A.A.; Plomp, J.

    2008-01-01

    The propagation of the mutual coherence function is a well known method to describe the effects of neutron’s propagation through scattering instruments. This method is extended with the description of the coherence matrix to account for neutron polarization effects and its propagation through an ins

  15. Applied research of environmental monitoring using instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Young Sam; Moon, Jong Hwa; Chung, Young Ju

    1997-08-01

    This technical report is written as a guide book for applied research of environmental monitoring using Instrumental Neutron Activation Analysis. The contents are as followings; sampling and sample preparation as a airborne particulate matter, analytical methodologies, data evaluation and interpretation, basic statistical methods of data analysis applied in environmental pollution studies. (author). 23 refs., 7 tabs., 9 figs.

  16. Instrumental Neutron Activation Analysis Technique using Subsecond Radionuclides

    DEFF Research Database (Denmark)

    Nielsen, H.K.; Schmidt, J.O.

    1987-01-01

    The fast irradiation facility Mach-1 installed at the Danish DR 3 reactor has been used in boron determinations by means of Instrumental Neutron Activation Analysis using12B with 20-ms half-life. The performance characteristics of the system are presented and boron determinations of NBS standard...

  17. New Very Small Angle Neutron Scattering (VSANS) Instrument

    Science.gov (United States)

    Van Every, E.; Deyhim, A.; Kulesza, J.

    2016-09-01

    The design of a new Very Small Angle Neutron Scattering (VSANS) Instrument for use in National Institute of Standards And Technology (NIST) will be discussed. This instrument is similar to a shorter instrument we designed and delivered to ANSTO in Australia called the Bilby SANS instrument. The NIST VSANS and the ANSTO Bilby SANS instruments have very similar dimensions for length and diameter and have similar requirements for internal detector motion, top access port, walkway supports, and ports; however, the Bilby SANS instrument vacuum requirement was lower (7.5×10-5 Torr) and the entire (60,000 pound) vessel was required to move 1.5 meters on external rails with a repeatability of 100 um, which ADC achieved. The NIST VSANS length is 24 meter, internal diameter 2.3 meter with three internal carriages. The NIST VSANS instrument, which covers the usual SANS range will also allow configuration to cover the range between q ∼⃒ 10-4 A-1 to 10-3 A-1 with a sample beam current of (104 neutrons/s). The key requirements are a second position-sensitive detector system having a 1 mm pixel size and a longer sample-detector flight path of 20 m (i.e., a 40 m instrument).

  18. Neutrons and music: Imaging investigation of ancient wind musical instruments

    Energy Technology Data Exchange (ETDEWEB)

    Festa, G., E-mail: giulia.festa@roma2.infn.it [Università degli Studi di Roma Tor Vergata (Italy); Università degli Studi di Milano-Bicocca (Italy); Consiglio Nazionale delle Ricerche-IPCF, Messina (Italy); Tardino, G. [BauArt Basel, Basel (Switzerland); Pontecorvo, L. [Conservatorio di Cosenza – Cosenza Conservatory (Italy); Mannes, D.C. [Paul Scherrer Institut, Villigen (Switzerland); Senesi, R. [Università degli Studi di Roma Tor Vergata (Italy); Consiglio Nazionale delle Ricerche-IPCF, Messina (Italy); Gorini, G. [Università degli Studi di Milano-Bicocca (Italy); Andreani, C. [Università degli Studi di Roma Tor Vergata (Italy); Consiglio Nazionale delle Ricerche-IPCF, Messina (Italy)

    2014-10-01

    A set of seven musical instruments and two instruments cares from the ‘Fondo Antico della Biblioteca del Sacro Convento’ in Assisi, Italy, were investigated through neutron and X-ray imaging techniques. Historical and scientific interests around ancient musical instruments motivate an intense research effort for their characterization using non-destructive and non-invasive techniques. X-ray and neutron tomography/radiography were applied to the study of composite material samples containing wood, hide and metals. The study was carried out at the NEUTRA beamline, PSI (Paul Scherrer Institute, Switzerland). Results of the measurements provided new information on the composite and multi-scale structure, such as: the internal structure of the samples, position of added materials like metals, wood fiber displays, deformations, presence of adhesives and their spatial distribution and novel insight about construction methods to guide the instruments’ restoration process.

  19. Neutron cross section standards and instrumentation. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Wasson, O.A.

    1993-07-01

    The objective of this interagency program is to provide accurate neutron interaction measurements for the US Department of Energy nuclear programs which include waste disposal, fusion, safeguards, defense, fission, and personnel protection. These measurements are also useful to other energy programs which indirectly use the unique properties of the neutron for diagnostic and analytical purposes. The work includes the measurement of reference cross sections and related neutron data employing unique facilities and capabilities at NIST and other laboratories as required; leadership and participation in international intercomparisons and collaborations; the preservation of standard reference deposits and the development of improved neutron detectors and measurement methods. A related and essential element of the program is critical evaluation of neutron interaction data including international coordinations. Data testing of critical data for important applications is included. The program is jointly supported by the Department of Energy and the National Institute of Standards and Technology. This report from the National Institute of Standards and Technology contains a summary of the accomplishments of the Neutron Cross Section Standards and Instrumentation Project during the third year of this three-year interagency agreement. The proposed program and required budget for the following three years are also presented. The program continues the shifts in priority instituted in order to broaden the program base.

  20. Ortho- and para-hydrogen in neutron thermalization

    Energy Technology Data Exchange (ETDEWEB)

    Daemen, L. L.; Brun, T. O.

    1998-01-01

    The large difference in neutron scattering cross-section at low neutron energies between ortho- and para-hydrogen was recognized early on. In view of this difference (more than an order of magnitude), one might legitimately ask whether the ortho/para ratio has a significant effect on the neutron thermalization properties of a cold hydrogen moderator. Several experiments performed in the 60`s and early 70`s with a variety of source and (liquid hydrogen) moderator configurations attempted to investigate this. The results tend to show that the ortho/para ratio does indeed have an effect on the energy spectrum of the neutron beam produced. Unfortunately, the results are not always consistent with each other and much unknown territory remains to be explored. The problem has been approached from a computational standpoint, but these isolated efforts are far from having examined the ortho/para-hydrogen problem in neutron moderation in all its complexity. Because of space limitations, the authors cannot cover, even briefly, all the aspects of the ortho/para question here. This paper will summarize experiments meant to investigate the effect of the ortho/para ratio on the neutron energy spectrum produced by liquid hydrogen moderators.

  1. NEUTRON SCATTERING INSTRUMENTATION FOR MEASUREMENT OF MELT STRUCTURE

    Energy Technology Data Exchange (ETDEWEB)

    Richard Weber, Christopher Benmore

    2004-10-21

    This Phase II research project was focused on constructing and testing a facility for the measurement of the structure of hot solid and liquid materials under extreme conditions using neutron diffraction. The work resulted in measurements at temperatures of 3300 K, the highest ever performed in a neutron beam. Work was performed jointly by Containerless Research, Inc. and Argonne National Laboratory with significant interactions with engineers and scientists at the under construction-SNS facility in Oak Ridge, TN. The work comprised four main activities: Design and construct an advanced instrument for structural studies of liquids and hot solids using neutron scattering. Develop and test a software package for instrument control, data acquisition and analysis. Test and demonstrate the instrument in experiments at the GLAD beamline at IPNS. Evaluate requirements for performing experiments at the SNS. Develop interest from the potential user base and identify potential support for Phase III. The objectives of the research were met. A second-generation instrument was developed and constructed. The instrument design drew on the results of a formal design review which was held at Argonne National Laboratory during the Phase I research [1]. The review included discussion with potential instrument users, SNS scientists and engineers and various scientists involved with materials, glass, ceramics, and geological sciences. The instrument combines aerodynamic levitation with pulsed neutron diffraction in a controlled atmosphere. An important innovation was the use of pure vanadium levitation nozzles that effectively eliminated contributions from the sample environment to the measured data. The instrument employed a 250 Watt CO2 laser that was configured for Class I laser operation. The use of Class I laser configuration meant that operators could work with the equipment with minimal restrictions and so concentrate on the research activities. Instrument control and data

  2. Intercomparison of radiation protection instrumentation in a pulsed neutron field

    CERN Document Server

    Caresana, M; Esposito, A; Ferrarini, M; Golnik, N; Hohmann, E; Leuschner, A; Luszik-Bhadra, M; Manessi, G; Mayer, S; Ott, K; Röhrich, J; Silari, M; Trompier, F; Volnhals, M; Wielunski, M

    2014-01-01

    In the framework of the EURADOS working group 11, an intercomparison of active neutron survey meters was performed in a pulsed neutron field (PNF). The aim of the exercise was to evaluate the performances of various neutron instruments, including commercially available rem-counters, personal dosemeters and instrument prototypes. The measurements took place at the cyclotron of the Helmholtz-Zentrum Berlin für Materialien und Energie GmbH. The cyclotron is routinely used for proton therapy of ocular tumours, but an experimental area is also available. For the therapy the machine accelerates protons to 68 MeV. The interaction of the proton beam with a thick tungsten target produces a neutron field with energy up to about 60 MeV. One interesting feature of the cyclotron is that the beam can be delivered in bursts, with the possibility to modify in a simple and flexible way the burst length and the ion current. Through this possibility one can obtain radiation bursts of variable duration and intensity. All instru...

  3. Data acquisition and instrument control system for neutron spectrometers

    Science.gov (United States)

    Naik, S. S.; Kotwal, Ismat; Chandak, R. M.; Gaonkar, V. G.

    2004-08-01

    A personal computer (PC)-based data acquisition and instrument control system has been developed for neutron spectrometers in Dhruva reactor hall and Guide Tube laboratory. Efforts have been made to make the system versatile so that it can be used for controlling various neutron spectrometers using single end-on detector in step scan mode. Commercially available PC add-on cards have been used for input--output and timer-counter operations. An interface card and DC motor driver card have been developed indigenously. Software for the system has been written in Visual C++ language using MS Windows operating system. This data acquisition and instrument control system is successfully controlling four spectrometers at Dhruva reactor.

  4. Data acquisition and instrument control system for neutron spectrometers

    Indian Academy of Sciences (India)

    S S Naik; Ismat Kotwal; R M Chandak; V G Gaonkar

    2004-08-01

    A personal computer (PC)-based data acquisition and instrument control system has been developed for neutron spectrometers in Dhruva reactor hall and Guide Tube laboratory. Efforts have been made to make the system versatile so that it can be used for controlling various neutron spectrometers using single end-on detector in step scan mode. Commercially available PC add-on cards have been used for input–output and timer-counter operations. An interface card and DC motor driver card have been developed indigenously. Software for the system has been written in Visual C++ language using MS Windows operating system. This data acquisition and instrument control system is successfully controlling four spectrometers at Dhruva reactor.

  5. Instrumentation for PSD-based neutron diffractometers at Dhruva reactor

    Indian Academy of Sciences (India)

    S S Pande; S P Borkar; S Prafulla; V D Srivastava; A Behare; P K Mukhopadhyay; M D Ghodgaonkar; S K Kataria

    2004-08-01

    Linear position sensitive detectors (PSDs) are widely used to configure neutron diffractometers and other instruments. Necessary front-end electronics and a data acquisition system [1] is developed to cater to such instruments built around the Dhruva research reactor in BARC. These include three diffractometers with multiple PSDs and four with single PSD. The front-end electronics consists of high voltage units, preamplifiers [2], shaping amplifiers, ratio ADCs (RDC) [3]. The data acquisition system consists of an interface card and software. Commercially available hardware like temperature controller or stepper motor controller connected over GPIB or RS232 are also integrated in the data acquisition system. The data acquisition is automated so that it can continue unattended for control parameter like temperature, thus enabling optimum utilization of available beam time. The instrumentation is scalable and can be easily configured for various instrumental requirements. The front-end electronics and the data acquisition system are described here.

  6. Understanding inelastically scattered neutrons from water on a time-of-flight small-angle neutron scattering (SANS) instrument

    CERN Document Server

    Doa, Changwoo; Stanley, Christopher; Gallmeier, Franz X; Doucet, Mathieu; Smith, Gregory S

    2013-01-01

    It is generally assumed by most of the small-angle neutron scattering (SANS) user community that a neutrons energy is unchanged during SANS measurements. Here, the scattering from water, specifically light water, was measured on the EQ-SANS instrument, a time-of-flight SANS instrument located at the Spallation Neutron Source of Oak Ridge National Laboratory. A significant inelastic process was observed in the TOF spectra of neutrons scattered from water. Analysis of the TOF spectra from the sample showed that the scattered neutrons have energies consistent with room-temperature thermal energies (~20 meV) regardless of the incident neutron energy. With the aid of Monte Carlo particle transport simulations, we conclude that the thermalization process within the sample results in faster neutrons that arrive at the detector earlier than expected based on the incident neutron energies. This thermalization process impacts the measured SANS intensities in a manner that will ultimately be sample- and temperature-depe...

  7. Quantitative neutron capture resonance analysis verified with instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Blaauw, M. E-mail: blaauw@iri.tudelft.nl; Postma, H.; Mutti, P

    2003-06-01

    The newly developed elemental analysis technique Neutron Resonance Capture Analysis (NRCA) was verified by analyzing a prehistoric bronze arrowhead with both NRCA and Instrumental Activation Analysis (INAA). In NRCA, elements are identified through their neutron resonance capture energies as determined through detection of prompt capture gamma-rays as a function of time of flight. The quantification is obtained from the resonance peak areas. Corrections are required for neutron-energy-dependent dead time and self-shielding, the latter also depending on Doppler broadening. The analysis program REFIT, of which the intended use is the determination of the resonance parameters, was used to this end. The agreement observed between INAA and NRCA results indicates that the NRCA results obtained are accurate.

  8. Upgrade of detectors of neutron instruments at Neutron Physics Laboratory in Řež

    Science.gov (United States)

    Litvinenko, E. I.; Ryukhtin, V.; Bogdzel, A. A.; Churakov, A. V.; Farkas, G.; Hervoches, Ch.; Lukas, P.; Pilch, J.; Saroun, J.; Strunz, P.; Zhuravlev, V. V.

    2017-01-01

    Three neutron instruments at the Neutron Physics Laboratory (NPL) in Řež near Prague - small-angle scattering (SANS) MAUD, strain scanner SPN-100 and strain diffractometer TKSN-400 - have been modernized recently with new 2D position-sensitive detectors (PSDs) from JINR, Dubna. Here we report on the progress made in relation to the possibilities of the diffractometers due to the improved performance of the detectors. The first part of the paper is dedicated to a detailed description of the hardware and software of the PSDs, as well as its integration with the in-house experimental control software. Then practical examples of neutron scattering experiments for each of the upgraded facilities are presented.

  9. LUPIN, a new instrument for pulsed neutron fields

    Science.gov (United States)

    Caresana, M.; Ferrarini, M.; Manessi, G. P.; Silari, M.; Varoli, V.

    2013-06-01

    A number of studies focused in the last decades on the development of survey meters to be used in pulsed radiation fields. This is a topic attracting widespread interest for applications such as radiation protection and beam diagnostics in accelerators. This paper describes a new instrument specifically conceived for applications in pulsed neutron fields (PNF). The detector, called LUPIN, is a rem counter type instrument consisting of a 3He proportional counter placed inside a spherical moderator. It works in current mode with a front-end electronics consisting of a current-voltage logarithmic amplifier, whose output signal is acquired with an ADC and processed on a PC. This alternative signal processing allows the instrument to be used in PNF without being affected by saturation effects. Moreover, it has a measurement capability ranging over many orders of burst intensity. Despite the fact that it works in current mode, it can measure a single neutron interaction. The LUPIN was first calibrated in CERN's calibration laboratory with a PuBe source. Measurements were carried out under various experimental conditions at the Helmholtz-Zentrum in Berlin, in the stray field at various locations of the CERN Proton Synchrotron complex and around a radiotherapy linear accelerator at the S. Raffaele hospital in Milan. The detector can withstand single bursts with values of H*(10) up to 16 nSv/burst without showing any saturation effect. It efficiently works in pulsed stray fields, where a conventional rem-counter underestimates by a factor of 2. It is also able to reject the very intense and pulsed photon contribution that often accompanies the neutron field with good reliability.

  10. Virtual experiments: Combining realistic neutron scattering instrument and sample simulations

    Science.gov (United States)

    Farhi, E.; Hugouvieux, V.; Johnson, M. R.; Kob, W.

    2009-08-01

    A new sample component is presented for the Monte Carlo, ray-tracing program, McStas, which is widely used to simulate neutron scattering instruments. The new component allows the sample to be described by its material dynamic structure factor, which is separated into coherent and incoherent contributions. The effects of absorption and multiple scattering are treated and results from simulations and previous experiments are compared. The sample component can also be used to treat any scattering material which may be close to the sample and therefore contaminates the total, measured signal.

  11. Neutron scattering and diffraction instrument for structural study on biology in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Niimura, Nobuo [Japan Atomic Energy Research Inst., Ibaraki-ken (Japan)

    1994-12-31

    Neutron scattering and diffraction instruments in Japan which can be used for structural studies in biology are briefly introduced. Main specifications and general layouts of the instruments are shown.

  12. Proceedings of a workshop on methods for neutron scattering instrumentation design

    Energy Technology Data Exchange (ETDEWEB)

    Hjelm, R.P. [ed.] [Los Alamos National Lab., NM (United States)

    1997-09-01

    The future of neutron and x-ray scattering instrument development and international cooperation was the focus of the workshop. The international gathering of about 50 participants representing 15 national facilities, universities and corporations featured oral presentations, posters, discussions and demonstrations. Participants looked at a number of issues concerning neutron scattering instruments and the tools used in instrument design. Objectives included: (1) determining the needs of the neutron scattering community in instrument design computer code and information sharing to aid future instrument development, (2) providing for a means of training scientists in neutron scattering and neutron instrument techniques, and (3) facilitating the involvement of other scientists in determining the characteristics of new instruments that meet future scientific objectives, and (4) fostering international cooperation in meeting these needs. The scope of the meeting included: (1) a review of x-ray scattering instrument design tools, (2) a look at the present status of neutron scattering instrument design tools and models of neutron optical elements, and (3) discussions of the present and future needs of the neutron scattering community. Selected papers were abstracted separately for inclusion to the Energy Science and Technology Database.

  13. Instrumental neutron activation analysis of sectioned hair strands for arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Guinn, V.P. [Univ. of Maryland, College Park, MD (United States)

    1996-12-31

    Instrumental neutron activation analysis (INAA) is a valuable and proven method for the quantitative analysis of sectioned human head hair specimens for arsenic - and, if arsenic is found to be present at high concentrations, the approximate times when it was ingested. Reactor-flux thermal-neutron activation of the hair samples produces 26.3-h {sup 76}As, which is then detected by germanium gamma-ray spectrometry, measuring the 559.1-keV gamma-ray peak of {sup 76}As. Even normal levels of arsenic in hair, in the range of <1 ppm up to a few parts per million of arsenic can be measured - and the far higher levels associated with large internal doses of arsenic, levels approaching or exceeding 100 ppm arsenic, are readily and accurately measurable. However, all phases of forensic investigations of possible chronic (or in some cases, acute) arsenic poisoning are important, i.e., not just the analysis phase. All of these phases are discussed in this paper, based on the author`s experience and the experience of others, in criminal cases. Cases of chronic arsenic poisoning often reveal a series of two to four doses, perhaps a few months apart, with increasing doses.

  14. BEAM INSTRUMENTATION FOR THE SPALLATION NEUTRON SOURCE RING.

    Energy Technology Data Exchange (ETDEWEB)

    WITKOVER,R.L.; CAMERON,P.R.; SHEA,T.J.; CONNOLLY,R.C.; KESSELMAN,M.

    1999-03-29

    The Spallation Neutron Source (SNS) will be constructed by a multi-laboratory collaboration with BNL responsible for the transfer lines and ring. [1] The 1 MW beam power necessitates careful monitoring to minimize un-controlled loss. This high beam power will influence the design of the monitors in the high energy beam transport line (HEBT) from linac to ring, in the ring, and in the ring-to-target transfer line (RTBT). The ring instrumentation must cover a 3-decade range of beam intensity during accumulation. Beam loss monitoring will be especially critical since un-controlled beam loss must be kept below 10{sup -4}. A Beam-In-Gap (BIG) monitor is being designed to assure out-of-bucket beam will not be lost in the ring.

  15. New developments in the McStas neutron instrument simulation package

    DEFF Research Database (Denmark)

    Willendrup, Peter Kjær; Bergbäck Knudsen, Erik; Klinkby, Esben Bryndt

    2014-01-01

    The McStas neutron ray-tracing software package is a versatile tool for building accurate simulators of neutron scattering instruments at reactors, short- and long-pulsed spallation sources such as the European Spallation Source. McStas is extensively used for design and optimization of instruments...

  16. Development and Test of a Neutron Imaging Setup at the PGAA Instrument at FRM II

    OpenAIRE

    Söllradl, S.; M. J. Mühlbauer; Kudejova, P.; Türler, Andreas

    2015-01-01

    We report on the developments of a neutron tomography setup at the instrument for prompt gamma-ray activation analysis (PGAA) at the Maier-Leibnitz Zentrum(MLZ). The recent developments are driven by the idea of combining the spatial information obtained with neutron tomography with the elemental information determined with PGAA, i.e. to further combine both techniques to an investigative technique called prompt gamma activation imaging (PGAI).At the PGAA instrument, a cold neutron flux of up...

  17. Portable system for periodical verification of area monitors for neutrons; Sistema portatil para verificacao periodica de monitores de area para neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Luciane de R.; Leite, Sandro Passos; Lopes, Ricardo Tadeu, E-mail: rluciane@ird.gov.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), RJ (Brazil). Programa de Energia Nuclear; Patrao, Karla C. de Souza; Fonseca, Evaldo S. da; Pereira, Walsan W., E-mail: karla@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiacoes Ionizantes (LNMRI). Lab. de Neutrons

    2009-07-01

    The Neutrons Laboratory develops a project viewing the construction of a portable test system for verification of functioning conditions of neutron area monitors. This device will allow to the users the verification of the calibration maintenance of his instruments at the use installations, avoiding the use of an inadequate equipment related to his answer to the neutron beam response

  18. Inglés instrumental para adultos

    OpenAIRE

    Fernández Sánchez, Eulalio; Torralbo Caballero, Juan de Dios

    2011-01-01

    Ofrecer material didáctico en inglés para la población adulta es la base de este proyecto, el primero de estas características que se desarrolla a nivel universitario hasta la fecha, puesto que no hay ningún otro publicado, ni tampoco elaborado. Su desarrollo se lleva a la práctica en tres módulos diferentes: cognitivo, asociativo y autónomo. Los autores de la iniciativa pretenden, además, grabar todo el material en soporte auditivo, del que se hará cargo el personal de la Universidad de Córd...

  19. Application of instrumental neutron activation analysis for determining As, Br, K, La, Mn, Na and Sm in samples of pine wood; Aplicacao da analise por ativacao neutronica instrumental para determinacao de As, Br, K, La, Mn, Na e Sm em amostras de madeiras de Pinus

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Helder de; Fernandes, Elisabete A. de Nadai; Bacchi, Marcio Arruda; Tagliaferro, Fabio Sileno [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil); Sarries, Gabriel Adrian [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz

    1999-11-01

    Multi-elementary and considered non destructive, the neutron activation analysis is a technique that allows simultaneous and instrumental determination of several elements, becoming especially useful when it is fundamental the knowledge of the total chemical composition, as in the certification of reference materials, application in geochemistry, analyses of aerosols, determination of origin of materials, forensic analyzes and of environmental pollution. However, the dependence of reactors, or other neutrons sources, the generation of radioactive material and the time waiting needed for some determinations are the main barriers pointed int he application of that technique. The present work aimed at establishing the best conditions for the detection of elements of short half-life Br, K, La, Mn, Na and Sm in samples of wood of Pinus, because the reactor used is located distant of the laboratory where the measures of the induced radioactivity are made, to determine trace elements that possess half-lives smaller than two days. For such, suitable equations, using the Surface of Response technique in the SAS software, to minimize the uncertainties of detection of the photopeak function of the elementary concentration and as a decay time.(author) 6 refs., 3 figs., 11 tabs.

  20. Understanding inelastically scattered neutrons from water on a time-of-flight small-angle neutron scattering (SANS) instrument

    Energy Technology Data Exchange (ETDEWEB)

    Do, Changwoo, E-mail: doc1@ornl.gov [Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Heller, William T.; Stanley, Christopher [Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Gallmeier, Franz X. [Instrument and Source Design Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Doucet, Mathieu [Neutron Data Analysis and Visualization Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Smith, Gregory S. [Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

    2014-02-11

    It is generally assumed by most of the small-angle neutron scattering (SANS) user community that a neutron's energy is unchanged during SANS measurements. Here, the scattering from water, specifically light water, was measured on the EQ-SANS instrument, a time-of-flight (TOF) SANS instrument located at the Spallation Neutron Source of Oak Ridge National Laboratory. A significant inelastic process was observed in the TOF spectra of neutrons scattered from water. Analysis of the TOF spectra from the sample showed that the scattered neutrons have energies consistent with room-temperature thermal energies (∼20 meV) regardless of the incident neutron's energy. With the aid of Monte Carlo particle transport simulations, we conclude that the thermalization process within the sample results in faster neutrons that arrive at the detector earlier than expected based on the incident neutron energies. This thermalization process impacts the measured SANS intensities in a manner that will ultimately be sample- and temperature-dependent, necessitating careful processing of the raw data into the SANS cross-section.

  1. Neutron guide system for small-angle neutron scattering instruments of the Jülich Centre for Neutron Science at the FRM-II

    Science.gov (United States)

    Radulescu, A.; Ioffe, A.

    2008-02-01

    Following the shut-down of the FRJ-2 research reactor in Jülich a large part of the neutron scattering instrumentation operating there is currently being moved to the FRM-II research reactor in Garching-München. The installation of these instruments requires the design and set-up of new neutron guides with geometrical and optical features imposed by the positioning of the instruments in the neutron guide hall and by the foreseen significant improvement of the instrument performance. Particularly three SANS diffractometers require a special approach due to on one hand, their pre-determined size and on the other hand, the demanded neutron wavelength range. Expected characteristics of three neutron guides (currently under construction) optimized using VITESS and McStas simulation packages, namely the vertically "S-shaped" guides serving the KWS2 and KWS1 conventional SANS instruments and the horizontally "S-shaped" guide serving the focusing KWS3 instrument, will be reported on.

  2. Neutron guide system for small-angle neutron scattering instruments of the Juelich Centre for Neutron Science at the FRM-II

    Energy Technology Data Exchange (ETDEWEB)

    Radulescu, A. [Institut fuer Festkoerperforschung, Forschungszentrum Juelich GmbH, Juelich Centre for Neutron Science at FRM II, Lichtenbergstr. 1, 85747 Garching (Germany)], E-mail: a.radulescu@fz-juelich.de; Ioffe, A. [Institut fuer Festkoerperforschung, Forschungszentrum Juelich GmbH, Juelich Centre for Neutron Science at FRM II, Lichtenbergstr. 1, 85747 Garching (Germany)

    2008-02-11

    Following the shut-down of the FRJ-2 research reactor in Juelich a large part of the neutron scattering instrumentation operating there is currently being moved to the FRM-II research reactor in Garching-Muenchen. The installation of these instruments requires the design and set-up of new neutron guides with geometrical and optical features imposed by the positioning of the instruments in the neutron guide hall and by the foreseen significant improvement of the instrument performance. Particularly three SANS diffractometers require a special approach due to on one hand, their pre-determined size and on the other hand, the demanded neutron wavelength range. Expected characteristics of three neutron guides (currently under construction) optimized using VITESS and McStas simulation packages, namely the vertically 'S-shaped' guides serving the KWS2 and KWS1 conventional SANS instruments and the horizontally 'S-shaped' guide serving the focusing KWS3 instrument, will be reported on.

  3. Small Angle Neutron Scattering instrument at Malaysian TRIGA reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shukri Mohd; Razali Kassim; Zal Uyun Mahmood [Malaysian Inst. for Nuclear Technology Research (MINT), Bangi, Kajang (Malaysia); Shahidan Radiman

    1998-10-01

    The TRIGA MARK II Research reactor at the Malaysian Institute for Nuclear Research (MINT) was commissioned in July 1982. Since then various works have been performed to utilise the neutrons produced from this steady state reactor. One of the project involved the Small Angle Neutron Scattering (SANS). (author)

  4. Global Maps of Lunar Neutron Fluxes from the LEND Instrument

    Science.gov (United States)

    Litvak, M. L.; Mitrofanov, I. G.; Sanin, A.; Malakhov, A.; Boynton, W. V.; Chin, G.; Droege, G.; Evans, L. G.; Garvin, J.; Golovin, D. V.; Harshman, K.; McClanahan, T. P.; Mokrousov, M. I.; Mazarico, E.; Milikh, G.; Neumann, G.; Sagdeev, R.; Smith, D. E.; Starr, R.; Zuber, M. T.

    2012-01-01

    The latest neutron spectrometer measurements with the Lunar Exploration Neutron Detector (LEND) onboard the Lunar Reconnaissance Orbiter (LRO) are presented. It covers more than 1 year of mapping phase starting on 15 September 2009. In our analyses we have created global maps showing regional variations in the flux of thermal (energy range 0.5 MeV), and compared these fluxes to variances in soil elemental composition, and with previous results obtained by the Lunar Prospector Neutron Spectrometer (LPNS). We also processed data from LEND collimated detectors and derived a value for the collimated signal of epithermal neutrons based on the comparative analysis with the LEND omnidirectional detectors. Finally, we have compared our final (after the data reduction) global epithermal neutron map with LPNS data.

  5. Monte Carlo simulations of neutron-scattering instruments using McStas

    Science.gov (United States)

    Nielsen, K.; Lefmann, K.

    2000-06-01

    Monte Carlo simulations have become an essential tool for improving the performance of neutron-scattering instruments, since the level of sophistication in the design of instruments is defeating purely analytical methods. The program McStas, being developed at Risø National Laboratory, includes an extension language that makes it easy to adapt it to the particular requirements of individual instruments, and thus provides a powerful and flexible tool for constructing such simulations. McStas has been successfully applied in such areas as neutron guide design, flux optimization, non-Gaussian resolution functions of triple-axis spectrometers, and time-focusing in time-of-flight instruments.

  6. Perspectives of extreme sample environment in neutron scattering and consequences for instrumentation

    Indian Academy of Sciences (India)

    Michael Steiner

    2008-11-01

    Because neutrons can penetrate bulky pieces of matter, increasingly complex sample environment is requested by the users of neutron beams. This corresponds to the ever-growing complexity of the scientific problems addressed by neutron scatterers. Until now such requirements could be satisfied by sample environment, which could be added to the instruments without major modifications. Now it becomes evident, that for certain applications further progress is possible only by bringing the neutrons to the sample environment instead of bringing the sample environment to the neutrons. As one of the first examples of this concept we will discuss the high field magnet (HFM), which Hahn-Meitner-Institute Berlin (HMI) and the National High Magnetic Field Laboratory Tallahassy (NHFML) are constructing jointly for BENSC at HMI. At BENSC the HMI has built in the meantime a dedicated instrument based on the TOF principle to be equipped with the HFM to enable experiments at fields up to 25 T.

  7. Neutron spectrum for neutron capture therapy in boron; Espectro de neutrones para terapia por captura de neutrones en boro

    Energy Technology Data Exchange (ETDEWEB)

    Medina C, D.; Soto B, T. G. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Programa de Doctorado en Ciencias Basicas, 98068 Zacatecas, Zac. (Mexico); Baltazar R, A. [Universidad Autonoma de Zacatecas, Unidad Academica de Ingenieria Electrica, Programa de Doctorado en Ingenieria y Tecnologia Aplicada, 98068 Zacatecas, Zac. (Mexico); Vega C, H. R., E-mail: dmedina_c@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2016-10-15

    Glioblastoma multiforme is the most common and aggressive of brain tumors and is difficult to treat by surgery, chemotherapy or conventional radiation therapy. One treatment alternative is the Neutron Capture Therapy in Boron, which requires a beam modulated in neutron energy and a drug with {sup 10}B able to be fixed in the tumor. When the patients head is exposed to the neutron beam, they are captured by the {sup 10}B and produce a nucleus of {sup 7}Li and an alpha particle whose energy is deposited in the cancer cells causing it to be destroyed without damaging the normal tissue. One of the problems associated with this therapy is to have an epithermal neutrons flux of the order of 10{sup 9} n/cm{sup 2}-sec, whereby irradiation channels of a nuclear research reactor are used. In this work using Monte Carlo methods, the neutron spectra obtained in the radial irradiation channel of the TRIGA Mark III reactor are calculated when inserting filters whose position and thickness have been modified. From the arrangements studied, we found that the Fe-Cd-Al-Cd polyethylene filter yielded a ratio between thermal and epithermal neutron fluxes of 0.006 that exceeded the recommended value (<0.05), and the dose due to the capture gamma rays is lower than the dose obtained with the other arrangements studied. (Author)

  8. Instrumental neutron activation analysis of some ayurvedic medicines: Pt. 1

    Energy Technology Data Exchange (ETDEWEB)

    Rajurkar, N.S.; Vinchurkar, M.S. (Poona Univ., Pune (India). Dept. of Chemistry)

    1992-12-01

    Several medicines have been manufactured and prescribed to overcome mineral deficiencies in the human body. Such medicines are mixtures of several components. The present work is undertaken to analyze various Ayurvedic medicines, mainly of herbal origin and used for different purposes, for their elemental contents, by neutron activation analysis. (author).

  9. The upgraded cold neutron triple-axis spectrometer FLEXX – enhanced capabilities by new instrumental options

    Directory of Open Access Journals (Sweden)

    Habicht Klaus

    2015-01-01

    Full Text Available The upgrade of the cold neutron triple axis spectrometer FLEXX, a work-horse instrument for inelastic neutron scattering matching the sample environment capabilities at Helmholtz-Zentrum Berlin, has been successfully accomplished. Experiments confirmed an order of magnitude gain in flux now allowing for intensity demanding options to be fully exploited at FLEXX. In this article, we describe the layout and design of two newly available FLEXX instrument options in detail. The new Heusler analyzer gives an increase of the detected polarized neutron flux due to its superior focusing properties, significantly improving the feasibility of future polarized and neutron resonance spin echo experiments. The MultiFLEXX option provides simultaneous access to large regions in wavevector and energy space for inelastic excitations thus adding mapping capabilities to the spectrometer.

  10. Development and Test of a Neutron Imaging Setup at the PGAA Instrument at FRM II

    Science.gov (United States)

    Söllradl, S.; Mühlbauer, M. J.; Kudejova, P.; Türler, A.

    We report on the developments of a neutron tomography setup at the instrument for prompt gamma-ray activation analysis (PGAA) at the Maier-Leibnitz Zentrum(MLZ). The recent developments are driven by the idea of combining the spatial information obtained with neutron tomography with the elemental information determined with PGAA, i.e. to further combine both techniques to an investigative technique called prompt gamma activation imaging (PGAI).At the PGAA instrument, a cold neutron flux of up to 6 x 1010 cm-2 s-1 (thermal equivalent) is available in the focus of an elliptically tapered neutron guide. In the reported experiments, the divergence of the neutron beam was investigated, the resolution of the installed detector system tested, and a proof-of-principle tomography experiment performed. In our study a formerly used camera box was upgraded with a better camera and an optical resolution of 8 line pairs/mm was achieved. The divergence of the neutron beam was measured by a systematic scan along the beam axis. Based on the acquired data, a neutron imaging setup with a L/D ratio of 200 was installed. The resolution of the setup was testedin combination with a gadolinium test target and different scintillator screens. The test target was irradiated at two positions to determine the maximum resolution and the resolution at the actual sample position. The performance of the installed tomography setup was demonstrated bya tomography experiment of an electric amplifier tube.

  11. Neutron detector array at IUAC: Design features and instrumentation developments

    Indian Academy of Sciences (India)

    P Sugathan; A Jhingan; K S Golda; T Varughese; S Venkataramanan; N Saneesh; V V Satyanarayana; S K Suman; J Antony; Ruby Shanti; K Singh; S K Saini; A Gupta; A Kothari; P Barua; Rajesh Kumar; J Zacharias; R P Singh; B R Behera; S K Mandal; I M Govil; R K Bhowmik

    2014-11-01

    The characteristics and performance of the newly commissioned neutron detector array at IUAC are described. The array consists of 100 BC501 liquid scintillators mounted in a semispherical geometry and are kept at a distance of 175 cm from the reaction point. Each detector is a 5″ × 5″ cylindrical cell coupled to 5″ diameter photomultiplier tube (PMT). Signal processing is realized using custom-designed home-made integrated electronic modules which perform neutron–gamma discrimination using zero cross timing and time-of-flight (TOF) technique. Compact custom-built high voltage power supply developed using DC–DC converters are used to bias the detector. The neutrons are recorded in coincidence with fission fragments which are detected using multi-wire proportional counters mounted inside a 1m diameter SS target chamber. The detectors and electronics have been tested off-line using radioactive sources and the results are presented.

  12. Bragg optics computer codes for neutron scattering instrument design

    Energy Technology Data Exchange (ETDEWEB)

    Popovici, M.; Yelon, W.B.; Berliner, R.R. [Missouri Univ. Research Reactor, Columbia, MO (United States); Stoica, A.D. [Institute of Physics and Technology of Materials, Bucharest (Romania)

    1997-09-01

    Computer codes for neutron crystal spectrometer design, optimization and experiment planning are described. Phase space distributions, linewidths and absolute intensities are calculated by matrix methods in an extension of the Cooper-Nathans resolution function formalism. For modeling the Bragg reflection on bent crystals the lamellar approximation is used. Optimization is done by satisfying conditions of focusing in scattering and in real space, and by numerically maximizing figures of merit. Examples for three-axis and two-axis spectrometers are given.

  13. Determination of Lithium by Instrumental Neutron Activation Analysis

    DEFF Research Database (Denmark)

    Heydorn, Kaj; Skanborg, Preben Zacho; Gwozdz, R.

    1977-01-01

    The fast transfer system in the DR 2 reactor for irradiation at a thermal neutron flux density of 1013 n·cm−2·sec−1 was used for the determination of lithium by the7Li(n, γ)8Li reaction. β-counting with a large perspex Cerenkov detector begun at 0.3 s after the end of irradiation, and multi...

  14. New developments in the McStas neutron instrument simulation package

    OpenAIRE

    Willendrup, Peter Kjær; Bergbäck Knudsen, Erik; Klinkby, Esben Bryndt; Nielsen, T.; Farhi, E.; Filges, U.; Lefmann, K.

    2014-01-01

    The McStas neutron ray-tracing software package is a versatile tool for building accurate simulators of neutron scattering instruments at reactors, short- and long-pulsed spallation sources such as the European Spallation Source. McStas is extensively used for design and optimization of instruments, virtual experiments, data analysis and user training. McStas was founded as a scienti_c, open-source collaborative code in 1997. This contribution presents the project at its current state and giv...

  15. Ground tests with active neutron instrumentation for the planetary science missions

    Energy Technology Data Exchange (ETDEWEB)

    Litvak, M.L., E-mail: litvak@mx.iki.rssi.ru [Space Research Institute, RAS, Moscow 117997 (Russian Federation); Mitrofanov, I.G.; Sanin, A.B. [Space Research Institute, RAS, Moscow 117997 (Russian Federation); Jun, I. [Jet Propulsion Laboratory, Pasadena, CA USA (United States); Kozyrev, A.S. [Space Research Institute, RAS, Moscow 117997 (Russian Federation); Krylov, A.; Shvetsov, V.N.; Timoshenko, G.N. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Starr, R. [Catholic University of America, Washington DC (United States); Zontikov, A. [Joint Institute for Nuclear Research, Dubna (Russian Federation)

    2015-07-11

    We present results of experimental work performed with a spare flight model of the DAN/MSL instrument in a newly built ground test facility at the Joint Institute for Nuclear Research. This instrument was selected for the tests as a flight prototype of an active neutron spectrometer applicable for future landed missions to various solid solar system bodies. In our experiment we have fabricated simplified samples of planetary material and tested the capability of neutron activation methods to detect thin layers of water/water ice lying on top of planetary dry regolith or buried within a dry regolith at different depths.

  16. Demonstration of a novel focusing small-angle neutron scattering instrument equipped with axisymmetric mirrors

    CERN Document Server

    Liu, Dazhi; Gubarev, Mikhail V; Robertson, J Lee; Crow, Lowell; Ramsey, Brian D; Moncton, David E

    2013-01-01

    Small-angle neutron scattering (SANS) is the most significant neutron technique in terms of impact on science and engineering. However, the basic concept of SANS facilities has not changed since the technique's inception about 40 years ago, as all SANS instruments, save a few, are still designed as pinhole cameras. Here we demonstrate a novel concept for a SANS instrument, based on axisymmetric focusing mirrors. We build and test a small prototype, which shows a performance comparable to that of conventional large SANS facilities. By using a detector with 50-micron pixels, we build the most compact SANS instrument in the world. This work, together with the recent demonstration that such mirrors could increase the signal rate at least 50-fold, while improving resolution, paves the way to novel SANS instruments, thus affecting a broad community of scientists and engineers.

  17. Monte Carlo simulations of neutron-scattering instruments using McStas

    DEFF Research Database (Denmark)

    Nielsen, K.; Lefmann, K.

    2000-01-01

    an extension language that makes it easy to adapt it to the particular requirements of individual instruments, and thus provides a powerful and flexible tool for constructing such simulations. McStas has been successfully applied in such areas as neutron guide design, flux optimization, non-Gaussian resolution...... functions of triple-axis spectrometers, and time-focusing in time-of-flight instruments. (C) 2000 Published by Elsevier Science B.V. All rights reserved....

  18. Experiment Automation with a Robot Arm using the Liquids Reflectometer Instrument at the Spallation Neutron Source

    Energy Technology Data Exchange (ETDEWEB)

    Zolnierczuk, Piotr A [ORNL; Vacaliuc, Bogdan [ORNL; Sundaram, Madhan [ORNL; Parizzi, Andre A [ORNL; Halbert, Candice E [ORNL; Hoffmann, Michael C [ORNL; Greene, Gayle C [ORNL; Browning, Jim [ORNL; Ankner, John Francis [ORNL

    2013-01-01

    The Liquids Reflectometer instrument installed at the Spallation Neutron Source (SNS) enables observations of chemical kinetics, solid-state reactions and phase-transitions of thin film materials at both solid and liquid surfaces. Effective measurement of these behaviors requires each sample to be calibrated dynamically using the neutron beam and the data acquisition system in a feedback loop. Since the SNS is an intense neutron source, the time needed to perform the measurement can be the same as the alignment process, leading to a labor-intensive operation that is exhausting to users. An update to the instrument control system, completed in March 2013, implemented the key features of automated sample alignment and robot-driven sample management, allowing for unattended operation over extended periods, lasting as long as 20 hours. We present a case study of the effort, detailing the mechanical, electrical and software modifications that were made as well as the lessons learned during the integration, verification and testing process.

  19. New developments in the McStas neutron instrument simulation package

    Science.gov (United States)

    Willendrup, P. K.; Knudsen, E. B.; Klinkby, E.; Nielsen, T.; Farhi, E.; Filges, U.; Lefmann, K.

    2014-07-01

    The McStas neutron ray-tracing software package is a versatile tool for building accurate simulators of neutron scattering instruments at reactors, short- and long-pulsed spallation sources such as the European Spallation Source. McStas is extensively used for design and optimization of instruments, virtual experiments, data analysis and user training. McStas was founded as a scientific, open-source collaborative code in 1997. This contribution presents the project at its current state and gives an overview of the main new developments in McStas 2.0 (December 2012) and McStas 2.1 (expected fall 2013), including many new components, component parameter uniformisation, partial loss of backward compatibility, updated source brilliance descriptions, developments toward new tools and user interfaces, web interfaces and a new method for estimating beam losses and background from neutron optics.

  20. Diamond mosaic crystals for neutron instrumentation: First experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Freund, A.K., E-mail: kafreund@free.f [Via Cordis, 92 Rue Abbe de l' Epee, F-33000 Bordeaux (France); Institut Max von Laue-Paul Langevin, B.P. 156, F-38042 Grenoble Cedex (France); Gsell, S.; Fischer, M.; Schreck, M. [Institut fuer Physik, Universitaet Augsburg, D-86135 Augsburg (Germany); Andersen, K.H.; Courtois, P. [Institut Max von Laue-Paul Langevin, B.P. 156, F-38042 Grenoble Cedex (France); Borchert, G. [Forschungsneutronenquelle FRM2, D-85747 Garching (Germany); Skoulatos, M. [Helmholtz Center Berlin for Materials and Energy, D-14109 Berlin (Germany)

    2011-04-01

    Diamond single crystals were recently proposed as monochromators of unprecedented performance (Freund, 2009). In the present paper we describe how diamond crystals with a suitable mosaic spread can be produced using a specific plasma CVD technique. Up to 2 mm thick samples with an average mosaic spread of 0.2{sup o} have been produced. We report on X- and gamma-ray characterisation checking the uniformity of the mosaic structure and present the results of a first study regarding the neutron reflection properties of this outstanding material. These promising results show that the diamond diffraction properties are not too far from the theoretical expectations. For example, 34% peak reflectivity has been obtained for a 1 mm thick crystal at 1 A wavelength.

  1. Analytical capabilities of the new thermal neutron prompt gamma-ray activation analysis instrument at the National Institute of Standards and Technology Center for Neutron Research

    Energy Technology Data Exchange (ETDEWEB)

    Mackey, E.A. [National Institute of Standards and Technology, Analytical Chemistry Division, Gaithersburg, MD (United States); Anderson, D.L. [US Food and Drug Administration, Elemental Research Branch, College Park, MD (United States)

    2004-07-01

    A new thermal neutron prompt gamma-ray activation analysis (PGAA) instrument was designed and built to replace the original PGAA system at the National Institute of Standards and Technology's Center for Neutron Research. The new PGAA instrument was constructed to achieve a reduction of the fast neutron beam component, a reduction of background gamma-radiation (including gamma-ray lines that directly interfere with element analyses, low-energy scattered gamma rays, and Compton scattered gamma rays), improvement in element sensitivities and limits of detection (LODs), and a simplified instrument set-up procedure. (orig.)

  2. Availability of essential trace elements in Ayurvedic Indian medicinal herbs using instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Singh, V.; Garg, A.N. [Nagpur Univ. (India). Dept. of Chemistry

    1997-01-01

    Specific parts of several plants (fruits, leaves, stem, bark and roots) often used as medicines in the Indian Ayurvedic system have been analysed for 20 elements (As, Ba, Br, Ca, Cl, Co, Cr, Cu, Fe, K, Mn, Mo, Na, P, Rb, Sb, Sc, Se, Sr and Zn) by employing instrumental neutron activation analysis (INAA). The samples were irradiated with thermal neutrons in a nuclear reactor and the induced activity was counted using high resolution gamma ray spectrometry. Most of the medicinal herbs have been found to be rich in one or more of the elements under study. (Author).

  3. A model for non-thermalized neutron spectra emitted from para-hydrogen

    DEFF Research Database (Denmark)

    Schönfeldt, Troels; Batkov, K.; Klinkby, Esben Bryndt

    2016-01-01

    to the high radiation environment near the moderator and cooling demands. One of the very popular materials, used at J-PARC and planed for ESS, is the spin singlet state of H2, para-hydrogen. This study assesses the non-Maxwellian neutron spectral structure achieved in para-hydrogen moderators, which is due...... to the complexity of the inelastic scattering cross section below 50 meV. The analytical description of a thermalized spectrum with slowing down components are discussed, then a formula is developed which is a good description of this non-equilibrium para-hydrogen neutron spectrum.These analytical descriptions...

  4. New instruments and science around SINQ. Lecture notes of the 4. summer school on neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Furrer, A. [ed.

    1996-11-01

    The spallation neutron source at PSI will be commissioned towards the end of this year together with a set of first generation instruments. This facility should then be available for the initial scientific work after spring next year. One of the main goals of this year`s summer school for neutron scattering was therefore the preparation of the potential customers at this facility for its scientific exploitation. In order to give them the - so to speak - last finish, we have dedicated the school to the discussion of the instruments at SINQ and their scientific potential. These proceedings are divided into two parts: Part A gives a complete description of the first-generation instruments and sample environment at SINQ. For all the instruments the relevant parameters for planning experiments are listed. Part A is completed by G. Bauer`s summary on experimental facilities and future developments at SINQ. Part B presents the lecture notes dealing with relevant applications of neutron based techniques in science and technology. The summary lecture by S.W. Lovesey is also included. (author) figs., tabs., refs.

  5. Monte-Carlo simulations of a high-resolution neutron TOF instrument

    Science.gov (United States)

    Bernhardt, Ph; Demmel, F.; Magerl, A.

    2000-03-01

    It is proposed to build a flexible, high-resolution time-of-flight diffractometer and spectrometer at the new reactor FRM II of the Technische Universität München. To optimize the layout of individual components and to estimate the performance of the entire instrument, we have made analytical calculations and Monte-Carlo simulations mainly with “McStas”, programmed by RISØ, Denmark. MC simulation routines for neutron devices like curved guides, disc- and Fermi choppers have been added. The influence of curved guides in neutron phase space has been developed and will be presented. Line shapes of neutron pulses and transmission have been studied for a Fermi chopper with straight slits and will be compared with the results of simulation.

  6. Monte-Carlo calculation of the response functions for two prototype cosmic neutron metrology instruments

    Energy Technology Data Exchange (ETDEWEB)

    Benson, Chris; Joyce, Malcolm J.; Winsby, Andrew [Lancaster University, Engineering Department, Bailrigg, Lancaster LA1 4YR (United Kingdom); Silvie, Jon [BAE SYSTEMS, Barrow-in-Furness, LA14 1AF (United Kingdom)

    2002-08-01

    The response functions for two cosmic neutron detection systems have been calculated using Monte-Carlo computational methods. The detection systems that form the focus of this research are modified Leake detector designs in which a central thermal neutron detector is surrounded by a sphere of high-density polyethylene. In this arrangement, the surrounding polyethylene moderates the incident fast neutrons that are then detected by the central detector; in this case a {sup 3}He-filled proportional counter. In order to extend the response of these detector systems to cater for cosmic neutron environments, a shell of high-Z material has been included in each to promote (n, xn) reactions in the polyethylene moderator. We have used shells of lead and copper for this purpose to bring the high-energy component of the cosmic field, extending up to several GeV, within the capability of the detector systems. In particular, copper has been used in comparison with lead since the former is easier and safer to machine and handle. The overall diameter of the instruments studies in this work is 208 mm. Calculations of the neutron response have been performed with MCNP4C, for the thermal-20 MeV energy range, and with MCNPX 2.1.5/LA150N neutron libraries for the higher-energy cosmic region of the spectrum beyond 20 MeV. The results of these calculations are compared with experimental data that have been recorded with the instruments at the CERN Cosmic Reference Field Facility (CERF), Geneva, Switzerland. This comparison is discussed in respect of the likely applications of these detector systems to high-energy neutron field measurement on-board aircraft and in the vicinity of high-energy particle accelerators. The former application is gaining considerable research attention following the revised estimates of relative biological effectiveness of cosmic neutron fields and the related recommendation that aircrew be regarded occupationally-exposed radiation workers, on behalf of the

  7. Instrument intercomparison in the pulsed neutron fieldsat the CERN HiRadMat facility

    CERN Document Server

    Aza, E; Cassell, C; Charitonidis, N; Harrouch, E; Manessi, G P; Pangallo, M; Perrin, D; Samara, E; Silari, M

    2014-01-01

    An intercomparison of the performances of active neutron detectors was carried out in pulsed neutron fi elds in the new HiRadMat facility at CERN. Five detectors were employed: four of them (two ionization chambers and two rem counters) are routinely employed in the CERN radiation monitoring system, while the fi fth is a novel instrument, called LUPIN, speci fi cally conceived for applications in pulsed neutron fi elds. The measurements were performed in the stray fi eld generated by a proton beam of very short duration with momentum of 440 GeV/c impinging on a dump. The beam intensity was steadily increased during the experiment by more than three orders of magnitude, with an H*(10) due to neutrons at the detector reference positions varying between a few nSv per burst and a few m Sv per burst, whereas the gamma contribution to the total H*(10) was negligible. The aim of the experiment was to evaluate the linearity of the detector response in extreme pulsed conditions as a function of the neutron burst in- t...

  8. Neutron xyz - polarization analysis at a time-of-flight instrument

    Energy Technology Data Exchange (ETDEWEB)

    Ehlers, Georg [ORNL; Stewart, John Ross [ISIS Facility, Rutherford Appleton Laboratory; Andersen, Ken [ESS

    2015-01-01

    When implementing a dedicated polarization analysis setup at a neutron time-of-flight instrument with a large area detector, one faces enormous challenges. Nevertheless, significant progress has been made towards this goal over the last few years. This paper addresses systematic limitations of the traditional method that is used to make these measurements, and a possible strategy to overcome these limitations. This will be important, for diffraction as well as inelastic experiments, where the scattering occurs mostly out-of-plane.

  9. Instrumental neutron activation analysis of soil and sediment samples from Siwa Oasis, Egypt

    Science.gov (United States)

    Badawy, Wael M.; Ali, Khaled; El-Samman, Hussein M.; Frontasyeva, Marina V.; Gundorina, Svetlana F.; Duliu, Octavian G.

    2015-07-01

    Instrumental neutron activation analysis was used to study geochemical peculiarities of the Siwa Oasis in the Western Egyptian Desert. A total of 34 elements were determined in soil and sediment samples (Na, Mg, Al, Cl, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, As, Br, Rb, Sr, Zr, Sb, I, Cs, Ba, La, Ce, Nd, Eu, Tb, Dy, Tm, Yb, Hf, Ta, Th, and U). For data interpretation Cluster analysis was applied. Comparison with the available literature data was carried out.

  10. Salvinia auriculata: Aquatic bioindicator studied by instrumental neutron activation analysis (INAA)

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira Soares, Daniel Cristian; Figueiredo de Oliveira, Ester [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN), Avenida Antonio Carlos, 6627 Pampulha, CEP 30123-970 Belo Horizonte, Minas Gerais (Brazil); Fatima Silva, Gracia Divina de; Duarte, Lucienir Pains [Departamento de Quimica, ICEx, Nucleo de estudos de Plantas Medicinais (NEPLAM), Universidade Federal de Minas Gerais, Avenida Antonio Carlos, 6627 Pampulha, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Pott, Vali Joana [Empresa Brasileira de Agropecuaria (EMBRAPA), BR 262 km 4, Caixa Postal 154, CEP 79002-970 Campo Grande, Mato Grosso do Sul (Brazil); Vieira Filho, Sidney Augusto [Escola de Farmacia, DEFAR, Universidade Federal de Ouro Preto, Rua Costa Sena, 171, CEP 35400-000 Ouro Preto, Minas Gerais (Brazil)], E-mail: bibo@ef.ufop.br

    2008-05-15

    Through instrumental neutron activation analysis (INAA) the elemental chemical composition of Salvinia auriculata and Ouro Preto city public water was determined. Elements Ce, Th, Cr, Hf, Sb, Sc, Rb, Fe, Zn, Co, Au, La and Br were quantified. High chromium concentration was determined in this plant. But, chromium was determined only in low concentrations in the water. The results indicate the great capacity of this plant to absorb and accumulate inorganic elements.

  11. Neutron Measurement Instrumentation Development at KIT for the European ITER TBM

    Energy Technology Data Exchange (ETDEWEB)

    Klix, A.; Fischer, U.; Raj, P.; Reimann, Th.; Szalkai, D.; Tian, K. [Association KIT-EURATOM, Karlsruhe Institute of Technology, D-76344 Eggenstein-Leopoldshafen (Germany); Angelone, M. [Associazione ENEA-EURATOM sulla Fusione, ENEA C.R., I-00044 Frascati (Italy); Gehre, D. [Technical University of Dresden, D-01069 Dresden (Germany); Lyoussi, A. [CEA, DEN, DER, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St-Paul-Lez-Durance (France)

    2015-07-01

    Fusion power reactors will rely on the internal production of the fuel tritium from lithium in the tritium breeding blanket. Test Blanket Modules (TBM) will be installed in ITER with the aim to investigate the nuclear performance of different breeding blanket designs. Currently there is no fully qualified nuclear instrumentation available for the measurement of neutron fluxes and tritium production rates which would be able to withstand the harsh environment conditions in the TBM such as high temperature (>400 deg. C) and, depending on the operation scenario, intense radiation levels. As partner of the European Consortium on Nuclear Data and Measurement Techniques in the framework of several F4E specific grants and contracts, KIT and ENEA have jointly studied the possibility to develop and test detectors suitable to operate in ITER-TBMs. Here we present an overview of ongoing work on three types of neutron flux monitors under development for the TBMs with focus on the KIT activities. A neutron activation system (NAS) with pneumatic sample transport could provide absolute neutron flux measurements in selected positions. A test system for investigating activation materials with short half-lives was constructed at the DT neutron generator laboratory of Technical University of Dresden to investigate the neutronics aspects. Several irradiations have been performed with focus on the simultaneous measurement of the extracted activated probes. An engineering assessment of a TBM NAS in the conceptual design phase has been done which considered issues of design requirements and integration. Last but not least, a mechanical test bench is under construction at KIT which will address issues of driving the activation probes, solutions for loading the system etc. experimentally. Self-powered neutron detectors (SPND) are widely applied in fission reactor monitoring, and the commercially available SPNDs are sensitive to thermal neutrons. We are investigating novel materials for

  12. Computational program to neutron flux calculation; Programa computacional para calculo de fluxo de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Maria Ines Silvani; Furieri, Rosanne Cefaly de Aranda Amado [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil)

    2000-07-01

    The absolute value of the neutron flux is of paramount importance in reactor physics and other application on the nuclear field. Due to several corrections which should be done, such as radioactive decay of the produced nuclides, normalization factors between different irradiations, neutron spectrum perturbation, cross section behaviour and growing of the reactor power, among other factors, make the calculation of the neutron flux very cumbersome. the software FLUXO was developed to overcome these inconveniences. It is programmed in FORTRAN language, and was written to calculate the absolute flux of thermal, epithermal and fast neutrons, through the foil activation technique. The magnitude of this activation can be measured by a 4{pi} {beta}-{gamma} coincidence measurement or by gamma spectroscopy alone. The software calculates as well, the absolute activity of radioactive sources, and reactor-irradiated samples. (author)

  13. Modulation of the neutron spectrum for NCTB; Modulacion del espectro de neutrones para TCNB

    Energy Technology Data Exchange (ETDEWEB)

    Medina C, D.; Letechipia de L, C.; Vega C, H. R., E-mail: dmedina_c@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No.10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2016-09-15

    Cancer is characterized by the uncontrolled growth of differentiated cells in a part of the organism. Currently in the world there are millions of people living with cancer. Glioblastoma multiform e is the most common and most aggressive of brain tumors and is very difficult to treat by conventional surgery, chemotherapy or radiation. The only viable alternative is its treatment through Neutron Capture Therapy in Boron (NCTB), since is a selective therapy that requires a drug with {sup 10}B (a non-radioactive isotope of boron) and a modulated neutron beam. Thermal neutrons are captured by {sup 10}B, because has a large effective section of thermal neutron absorption, in an exothermic reaction forming the nucleus composed of {sup 11}B in an excited state that induces its cleavage in two nuclei: {sup 7}Li and alpha particle ({sup 4}He). This process causes the destruction of cancer cells by direct DNA damage, without damaging normal tissue. One of the problems associated with this therapy is to have a neutron beam with adequate flow and spectrum. The neutron spectrum must be moderated and filtered from the characteristics of the source. To this end, the main sources of neutrons are nuclear research reactors and particle accelerators. The intensity of the flow should be 2 x 10 E{sup 9} n/cm{sup 2}.s, in order to treat the patient in a reasonable time; thus, is interesting to design filters for a radial beam of a TRIGA reactor, where materials such as Cd, Al, Fe and polyethylene are being implemented in the interest of having a spectrum with which the therapy can be implemented. For this design is being played with the position of the materials, to be able to see the behavior of the spectrum and thus choose some arrangement as indicated, of course taking into account the doses of both neutrons and gammas. (Author)

  14. Routine determination of trace elements in fly ashes by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Szopa, Z.; Dybczynski, R.; Kulisa, K.; Sterlinski, S. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1994-12-31

    A method making possible routine determination of 24 trace elements in fly ashes by instrumental neutron activation analysis (INAA) is described. The method employs elemental standards, and the correction for neutron flux gradient in the irradiation package is performed with the aid of Au flux monitors. Important features of the method as: detectability, precision and accuracy are discussed in detail. Reliability of the method was demonstrated by the analysis of several certified reference materials (CRMs). Special attention was devoted to comparison of the experimentally obtained detection limits with those predicted by computer spectra simulation (CSS) method. The elemental enrichment factors calculated for Polish coal fly ash were compared with those typical for Chinese and Canadian fly ashes. (author). 21 refs, 7 figs.

  15. Instrumental neutron activities analysis of Marrubium vulgare L., a valuable medicinal herb

    Energy Technology Data Exchange (ETDEWEB)

    Nedjimi, Bouzid [Djelfa Univ. (Algeria). Lab. of Exploration and Valorization of Steppe Ecosystem; Beladel, Brahim [Djelfa Univ. (Algeria). Dept. of Physics

    2016-08-01

    Twenty two chemical elements were identified by Instrumental neutron activation analysis in Marrubium vulgare (Lamiaceae) a traditional medicine plant, used indigenously in Mediterranean basin to cure several diseases. The precision of the results was assessed by analyzing the certified reference material GBW 07605 (GSV-4) Tea leaves. Results showed that K was the dominant chemical element in studied plant (4.40%). The Ca and Fe mass fractions were also relatively high. However potential toxic elements in this Lamiaceae plant were within the safety limits suggested by WHO/FAO.

  16. Elemental analysis of soil and hair sample by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong Sam; Quraishi, Shamshad Begum; Moon, Jong Hwa; Kim, Sun Ha; Baek, Sung Yeoil; Kang, Sang Hoon; Lim, Jong Myoung; Cho, Hyun Je; Kim, Young Jin

    2004-03-01

    Myanmar soil sample was analyzed by using the instrumental neutron activation analysis. The elemental concentrations in the sample, altogether 34 elements, Al As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Ga, Gd, Hf, Ir, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Se, Sm, Th, Ti, V, Yb, Zn and Zr were determined. The concentration of 17 elements (Al, Au, Br, Ca, Cl, Cr, Cu, Co, Fe, Hg, K, Na, Mn, Mg, Sb, Se, Zn) in human hair samples were determined by INAA For quality control of analytical method, certified reference material was used.

  17. Multi-element determination in medicinal Juniper tree (Juniperus phoenicea by instrumental neutron activation analysis

    Directory of Open Access Journals (Sweden)

    Bouzid Nedjimi

    2015-04-01

    Full Text Available Red Juniper (Juniperus phoenicea, a local medicinal tree was collected and analyzed for 18 essential, non-essential and toxic elements using instrumental neutron activation analysis (INAA. The GBW 07605 (GSV-4 standard reference material was analyzed simultaneously with the plant samples, the results shown a good recovery and reproducibility of the method. Ca, K and Fe have been detected in good levels in this plant clarifying their possible contribution to curative properties. The data obtained in the present work will be helpful in the synthesis of new synthetic drugs which can be used for medicinal purpose.

  18. Preliminary approach to neutron instrument selection at ESS-Bilbao based on experience at ISIS molecular spectroscopy group

    Energy Technology Data Exchange (ETDEWEB)

    Vicente Bueno, J. P. de

    2014-07-01

    Collaborative efforts between the Neutronics and Target Design Group at the Instituto de Fusion Nuclear and the Molecular Spectroscopy Group at the ISIS Pulsed Neutron and Muon Source date back to 2012 in the context of the ESS-Bilbao project. The rationale for these joint activities was twofold, namely: to assess the realm of applicability of the low-energy neutron source proposed by ESS-Bilbao; and to explore instrument capabilities for pulsed-neutron techniques in the range 0.05-3 ms, a time range where ESS-Bilbao and ISIS could offer a significant degree of synergy and complementarity. As part of this collaboration, J.P. de Vicente has spent a three-month period within the ISIS Molecular Spectroscopy Group, to gain hands-on experience on the practical aspects of neutron-instrument design and the requisite neutron-transport simulations. Building upon these previous works, the primary aim of this report is to provide a self contained discussion of general criteria for instrument selection at ESS-Bilbao, the first accelerator-driven, low-energy neutron source designed in Spain. (Author)

  19. Implementation of gamma-ray instrumentation for solid solar system bodies using neutron activation method

    Energy Technology Data Exchange (ETDEWEB)

    Litvak, M.L., E-mail: litvak@mx.iki.rssi.ru [Space Research Institute, RAS, Moscow 117997 (Russian Federation); Golovin, D.V. [Space Research Institute, RAS, Moscow 117997 (Russian Federation); Jun, I. [Jet Propulsion Laboratory, Pasadena, CA (United States); Kozyrev, A.S.; Mitrofanov, I.G.; Sanin, A.B. [Space Research Institute, RAS, Moscow 117997 (Russian Federation); Shvetsov, V.N.; Timoshenko, G.N.; Zontikov, A. [Joint Institute for Nuclear Research, Dubna (Russian Federation)

    2016-06-21

    In this paper we present the results of ground tests performed with a flight model and with industry prototypes of passive and active gamma ray spectrometers with the objective of understanding their capability to distinguish the elemental composition of planetary bodies in the solar system. The gamma instrumentation, which was developed for future space missions was used in the measurements at a special ground test facility where a simulant of planetary material was fabricated with a martian-like composition. In this study, a special attention was paid to the gamma lines from activation reaction products generated by a pulsed neutron generator. The instrumentation was able to detect and identify gamma lines attributed to O, Na, Mg, Al, Si, K, Ca and Fe.

  20. Determination of uranium fission product interference factor for molybdenum quantification by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro Junior, Ibere S.; Saiki, Mitiko; Genezini, Frederico A.; Zahn, Guilherme S., E-mail: ibere@usp.br, E-mail: mitiko@ipen.br, E-mail: fredzini@ipen.br, E-mail: gzahn@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Instrumental Neutron Activation Analysis (INAA) is a technique that provides high precision and accuracy results for the concentration determinations of several elements in different kinds of matrices. However, if the sample contains high uranium concentration in their composition, INAA can provide inaccurate results due to uranium fission product interferences. The molybdenum is one of these elements that suffers interference by uranium fission product, because the {sup 99}Mo radioisotope formed by {sup 98}Mo neutron capture, used in INAA, is the same that formed in the uranium fission. This kind of interference can be solved by separation of uranium before irradiation or by determining the uranium interference factor to the radioisotope of interest and applying the correction. The present study aims at the following: (1) determination of the Mo interference factor (F{sub Exp}{sup Mo}) due to the uranium fission product {sup 99}Mo by irradiating standards of Mo and U with known masses of these elements (experimental interference factor); (2) determination of the theoretical F{sub Th}{sup Mo}, in this case it was necessary to determine the epithermal to thermal neutron flux ratio and use the reported nuclear parameters; (3) comparison of the results of the interference factor obtained with values reported in the literature. The interference factor for Mo analysis was obtained in a position 14b shelf 3 of the IEA-R1 nuclear research reactor. (author)

  1. Design of a system for neutrons dosimetry; Diseno de un sistema para dosimetria de neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Ceron, P.; Rivera, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Legaria No. 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Paredes G, L. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Azorin, J. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico); Sanchez, A. [IPN, Escuela Superior de Fisica y Matematicas, Av. Instituto Politecnico Nacional s/n, Col. San Pedro Zacatenco, 07738 Mexico D. F. (Mexico); Vega C, H. R., E-mail: victceronr@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-08-15

    At the present time diverse systems of detection of neutrons exist, as proportional counters based on BF{sub 3}, He{sub 3} and spectrometers of Bonner spheres. However, the cost and the complexity of the implementation of these systems put them far from the reach for dosimetric purposes. For these reasons a system of neutrons detection composed by a medium paraffin moderator that forms a 4π (spheres) arrangement and of several couples of thermoluminescent dosimeters TLD 600/TLD 700. The response of the system presents a minor repeatability to 5% in several assays when being irradiated with a {sup 239}PuBe source and a deviation of 13.8% in the Tl readings of four different spheres. The calibration factor of the system with regard to the neutrons source which was of 56.2 p Sv/nc also was calculated. These detectors will be used as passive monitors of photoneutrons in a radiotherapy room with lineal accelerator of high energy. (Author)

  2. Monte-Carlo simulation of an ultra small-angle neutron scattering instrument based on Soller slits

    Energy Technology Data Exchange (ETDEWEB)

    Rieker, T. [Univ. of New Mexico, Albuquerque, NM (United States); Hubbard, P. [Sandia National Labs., Albuquerque, NM (United States)

    1997-09-01

    Monte Carlo simulations are used to investigate an ultra small-angle neutron scattering instrument for use at a pulsed source based on a Soller slit collimator and analyzer. The simulations show that for a q{sub min} of {approximately}le-4 {angstrom}{sup -1} (15 {angstrom} neutrons) a few tenths of a percent of the incident flux is transmitted through both collimators at q=0.

  3. Concept for a time-of-flight Small Angle Neutron Scattering instrument at the European Spallation Source

    Energy Technology Data Exchange (ETDEWEB)

    Jaksch, S. [ESS Design Update Programme – Germany, Forschungszentrum Jülich GmbH, Jülich (Germany); Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Garching (Germany); Martin-Rodriguez, D. [ESS Design Update Programme – Germany, Forschungszentrum Jülich GmbH, Jülich (Germany); Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Garching (Germany); Neutron Optics and Shielding Group, European Spallation Source AB, Lund (Sweden); Ostermann, A. [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II) at Heinz Maier-Leibnitz Zentrum, Technische Universität Muünchen, Garching (Germany); Jestin, J. [Laboratoire Léon Brillouin, LLB, CEA—Saclay, Gif sur Yvette cedex (France); Duarte Pinto, S.; Bouwman, W.G. [Faculty of Applied Sciences, Delft University of Technology, Delft (Netherlands); Uher, J. [Amsterdam Scientific Instruments, Amsterdam (Netherlands); Engels, R. [Zentralinstitut für Elektronik (ZEA-2), Forschungszentrum Jülich GmbH, Jülich (Germany); Frielinghaus, H. [ESS Design Update Programme – Germany, Forschungszentrum Jülich GmbH, Jülich (Germany); Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Garching (Germany)

    2014-10-21

    A new Small Angle Neutron Scattering instrument is proposed for the European Spallation Source. The pulsed source requires a time-of-flight analysis of the gathered neutrons at the detector. The optimal instrument length is found to be rather large, which allows for a polarizer and a versatile collimation. The polarizer allows for studying magnetic samples and incoherent background subtraction. The wide collimation will host VSANS and SESANS options that increase the resolution of the instrument towards µm and tens of µm, respectively. Two 1 m{sup 2} area detectors will cover a large solid angle simultaneously. The expected gains for this new instrument will lie in the range between 20 and 36, depending on the assessment criteria, when compared to up-to-date reactor based instruments. This will open new perspectives for fast kinetics, weakly scattering samples, and multi-dimensional contrast variation studies.

  4. Concept for a Time-of-Flight Small Angle Neutron Scattering Instrument at the European Spallation Source

    CERN Document Server

    Jaksch, S; Ostermann, A; Jestin, J; Pinto, S Duarte; Bouwman, W G; Uher, J; Engels, R; Kemmerling, G; Hanslik, R; Frielinghaus, H

    2014-01-01

    A new Small Angle Neutron Scattering instrument is proposed for the European Spallation Source. The pulsed source requires a time-of-flight analysis of the gathered neutrons at the detector. The optimal instrument length is found to be rather large, which allows for a polarizer and a versatile collimation. The polarizer allows for studying magnetic samples and incoherent background subtraction. The wide collimation will host VSANS and SESANS options that increase the resolution of the instrument towards um and tens of um, respectively. Two 1m2 area detectors will cover a large solid angle simultaneously. The expected gains for this new instrument will lie in the range between 20 and 36, depending on the assessment criteria, when compared to up-to-date reactor based instruments. This will open new perspectives for fast kinetics, weakly scattering samples, and multi-dimensional contrast variation studies.

  5. Qualification of the monitor Pug-7N like dosimeter for neutrons; Habilitacion del monitor PUG-7N como dosimetro para neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Benites R, J. L. [Centro Estatal de Cancerologia de Nayarit, Av. Enfermeria, Fracc. Fray Junipero Serra, 63000 Tepic, Nayarit (Mexico); Vega C, H. R.; Murillo O, R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Velazquez F, J. B., E-mail: jlbenitesr@prodigy.net.mx [Universidad Autonoma de Nayarit, Postgrado CBAP, Carretera Tepic Compostela Km. 9, Xalisco, Nayarit (Mexico)

    2011-10-15

    By means of an inter-comparison method, the monitor for neutrons Pug-7N was enabled like dosimeter for neutrons of two magnitudes: the environmental equivalent dose, H*(10), and the H equivalent dose. The monitor Pug-7N has a plastic detector of scintillation Pns-20 that can be used inside or outside of its polyethylene cylindrical moderator. This designed to detect the neutrons presence that is shown in ana logical form by means of a fast count. Although the instrument is useful to detect the neutrons presence its design it does not allow to estimate the dose. With the purpose of enabling it as dosimeter for neutrons, their response was compared with the response of the area monitor for neutrons Bert hold Lb 6411 and Eberline NRD model Asp-1. Under the same irradiation conditions the 3 instruments were exposed to a source of {sup 241}AmBe of 3.7E(9) Bq (100 mCi) of activity whose spectrum and dosimetric magnitudes were determined with a spectrometric system of Bonner spheres with scintillator of {sup 6}Lil(Eu) and the NSDUAZ code. Conversion factors of H*(10)/cpm and H/cpm were obtained for the two options of the monitor detector Pug-7N, with this procedure the monitor Pug-7N besides determining the presence of neutrons, it has been enabled for their use as dosimeter for neutrons. (Author)

  6. Neutronics of a poisoned para-hydrogen moderator for a pulsed spallation neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Harada, Masahide [Neutron Facility Group, Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki-ken 319 1195 (Japan)]. E-mail: harada.masahide@jaea.go.jp; Watanabe, Noboru [Neutron Facility Group, Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki-ken 319 1195 (Japan); Teshigawara, Makoto [Neutron Facility Group, Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki-ken 319 1195 (Japan); Kai, Tetsuya [Neutron Facility Group, Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki-ken 319 1195 (Japan); Kato, Takashi [Neutron Facility Group, Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki-ken 319 1195 (Japan); Ikeda, Yujiro [Neutron Facility Group, Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki-ken 319 1195 (Japan)

    2007-05-11

    Neutronic performance of a poisoned hydrogen moderator was studied in details. Using a simple rectangular-shape moderator-model, its basic characteristics were studied as a function of the poison position. We, for the first time, turned up that the pulse width was rather decreasing with increasing the moderator thickness of the back part from the poison. This is due to the fact that source neutron pulses entering into a front part of the poison through the back part exhibit a fast rise shape while those from the target and the reflector through the decoupler and liner exhibit a broad shape. Next, we studied the pulse deterioration in regard to a finite beam-extraction-angle by using a more realistic moderator shape, canteen shape and a concave-shape. It turns out that the pulse deterioration is considerably large in both cases even at a small extraction angle. The concave-shape moderator indicates a finite improvement compared to the canteen-shape one. Finally, merits and demerits of two poison materials, Cadmium and Gadolinium, were discussed taking into account the burn-up issue of poison with the operation time.

  7. A fast-neutron generator for experiments; Um dispositivo gerador de neutrons rapidos para experimentacao

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Charles F.; Souza, Manuel Jorge M.T. de; Campos, Tarcisio P.R. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Programa de Pos-graduacao em Ciencias e Tecnicas Nucleares]. E-mail: campos@nuclear.ufmg.br

    2005-07-01

    The present article presents an irradiation device of fast neutrons generated by sealed sources of AmBe, placed diametrically opposed to a central channel. The paper addresses the project, the shield calculations using the nuclear code MCNP5, and radioprotection issues. Considerations of the assembly of the device will be presented. The device is in a licensing phase. A cylinder of 30 cm diameter and 200 cm length are positioned buried 200 cm deep, whose opening is in the level of the floor Six sealed sources are available for the load of the irradiator. The sources will be positioned inside of the irradiator, receiving a double cast, a polyethylene one and another made of a steel tube. In the bottom and top of the cylinder there are paraffin shielding and in the center a central channel exists for lifting down samples to the irradiation position. In the central channel of this irradiator, a guide tube holds safely the sample close to 60 mm at center distance from sources, diametrically placed. The system is built-in into the soil, with the opening in the floor and all stamped against humidity. The sample's space to be irradiated has 20cm{sup 3} and it receives irradiation of fast to thermal neutrons. At vertical level, the sources will be shielded with 120 cm of boronate paraffin. A solid cylinder of 10 cm of diameter is positioned internally in the irradiator. The cylinder receives a restraint so that it cannot be removed unaware. In the half middle of the cylinder an opening of 8 cm length exists, in the form of a camera. Puling over the cylinder in a meter height liberates the camera at the level of the floor for placement of samples, at the same time in that shields the hole with a meter of boronate paraffin. The sample is placed inside of the camera of steel. After going down the cylinder at level of sources the sample is irradiated. Radioprotection aspects will be presented. The neutron flux at camera position is close to 10{sup 8}n/cm{sup 2}.seg. at 6

  8. Determination of essential elements in commercial baby foods by INAA (Instrumental Neutron Activation Analysis)

    Energy Technology Data Exchange (ETDEWEB)

    Vallinoto, Priscila; Maihara, Vera A., E-mail: pvallinoto@ipen.br, E-mail: vmaihara@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The World Health Organization recommends that infants be breast feed exclusively at least six months after birth. After this period, it is recommended to introduce complementary foods, in order to meet nutritional amounts, minerals and energy needs of children. Commercial food products intended for infants form an important part of the diet for many babies, so it is very important that such food contains sufficient amounts of minerals. Inadequate complementary feeding is a major cause of high rates of malnutrition in developing countries. In this study, essential elements: Ca, Co, Cr, Cs, Fe, K, Na and Zn levels were determined in seven different commercial food products samples by Instrumental Neutron Activation Analysis. The seven baby food samples were acquired in the markets of Sao Paulo city. After 8-hour irradiations in the IEA-R1 nuclear research reactor under a thermal neutron flux of 10{sup 12} n cm{sup -2} s{sup -1}, the essential elements were determined and the concentrations obtained were lower than the WHO requirements. For validation of the methodology, INCT MPH-2 Mixed Polish Herbs and NIST SRM 1577{sup b} Bovine Liver were analysed. (author)

  9. Rare earth elements in core marine sediments of coastal East Malaysia by instrumental neutron activation analysis.

    Science.gov (United States)

    Ashraf, Ahmadreza; Saion, Elias; Gharibshahi, Elham; Mohamed Kamari, Halimah; Chee Kong, Yap; Suhaimi Hamzah, Mohd; Suhaimi Elias, Md

    2016-01-01

    A study was carried out on the concentration of REEs (Dy, Sm, Eu,Yb, Lu, La and Ce) that are present in the core marine sediments of East Malaysia from three locations at South China Sea and one location each at Sulu Sea and Sulawesi Sea. The sediment samples were collected at a depth of between 49 and 109 m, dried, and crushed to powdery form. The entire core sediments prepared for Instrumental Neutron Activation Analysis (INAA) were weighted approximately 0.0500 g to 0.1000 g for short irradiation and 0.1500 g to 0.2000 g for long irradiation. The samples were irradiated with a thermal neutron flux of 4.0×10(12) cm(-2) s(-1) in a TRIGA Mark II research reactor operated at 750 kW. Blank samples and standard reference materials SL-1 were also irradiated for calibration and quality control purposes. It was found that the concentration of REEs varies in the range from 0.11 to 36.84 mg/kg. The chondrite-normalized REEs for different stations suggest that all the REEs are from similar origins. There was no significant REEs contamination as the enrichment factors normalized for Fe fall in the range of 0.42-2.82. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Instrumental Neutron Activation Analysis- INAA: environmental studies in Das Velhas Basin, Minas Gerais, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Rabelo V, M.A.; Andrade Q, M.T. [Researcher of National Council for Scientific and Technological Development, CNPq, Center University of the East of Minas Gerais State, UNILESTE-MG (Brazil); Araujo M, R. [CDTN (Brazil); Albernaz A, I. [SCA- CNRS/USR/059, Lyon (France); Oliveira, A.H. de [Federal University of Minas Gerais State (Brazil)]. e-mail: marvv@cdtn.br

    2006-07-01

    The Instrumental Neutron Activation Analysis - INAA was applied to determine concentrations of several elements in unpolluted areas and in the mining and farming region of the Das Velhas Basin, Minas Gerais State, Brazil. INAA was applied using the TRIGA Mark I IPR - R1 reactor at the Nuclear Technology Development Center of the National Committee of Nuclear Energy (CDTN/CNEN), in Belo Horizonte city, Minas Gerais State. At 100 kW of potency the flux of neutrons is 6.6 10{sup 11} n.cm{sup -2}.s{sup -1}. The samples analyzed were: water; sediment; gravel of gold mine and forage. The obtained results for the Das Velhas Basin in water and sediment samples - mining companies region - show a high level ({mu}g/g) of contamination with the analyzed elements, mainly in the sediment samples. During the period of floods, in farming region hundreds of kilometers away, contamination is found in fish and forage, reaching and harming both people and animals that live in the marginal region. (Author)

  11. Testing The Cas A Neutron Star Temperature Decline With Other Chandra Instruments

    Science.gov (United States)

    Elshamouty, Khaled; Heinke, C. O.; Ho, W. C. G.; Patnaude, D. J.; Shternin, P. S.; Yakovlev, D. G.

    2012-01-01

    The neutron star in the Cassiopeia A supernova remnant is 330 years old, making it the youngest neutron star in the Milky Way. Heinke & Ho (2010) reported a rapid cooling drop of 4% in its surface temperature (21% drop in observed flux) from Chandra ACIS-S archival data between 2000 and 2009. This opened the suggestion of enhanced neutrino emission due to a superfluid transition in the core to account for the observed rapid cooling (Page et al. 2011, Shternin et al. 2011). Here we present analysis of archival Chandra ACIS-I, HRC-I and HRC-S data over the same time period to test the rate. We used the best ACIS-S carbon atmosphere spectral fits to infer the countrates corresponding to various temperatures, along with current (CALDB 4.4.6) estimates of the effective area and its changes over time for these cameras, to calculate the temperature drops in each instrument. We find that the HRC-I data are consistent with the ACIS-S result, though tending to smaller declines. The ACIS-I data suggest a slightly larger drop. The HRC-S data (with the longest exposures) indicate a marginal temperature decline of 0.9+0.7-0.7 % (90% conf.) over 9 years.

  12. The accuracy of instrumental neutron activation analysis of kilogram-size inhomogeneous samples.

    Science.gov (United States)

    Blaauw, M; Lakmaker, O; van Aller, P

    1997-07-01

    The feasibility of quantitative instrumental neutron activation analysis (INAA) of samples in the kilogram range without internal standardization has been demonstrated by Overwater et al. (Anal. Chem. 1996, 68, 341). In their studies, however, they demonstrated only the agreement between the "corrected" γ ray spectrum of homogeneous large samples and that of small samples of the same material. In this paper, the k(0) calibration of the IRI facilities for large samples is described, and, this time in terms of (trace) element concentrations, some of Overwater's results for homogeneous materials are presented again, as well as results obtained from inhomogeneous materials and subsamples thereof. It is concluded that large-sample INAA can be as accurate as ordinary INAA, even when applied to inhomogeneous materials.

  13. Chemical contents in Lygeum spartum L. using instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nedjimi, Bouzid [Djelfa Univ. (Algeria). Lab. of Exploration and Valorization of Steppe Ecosystem; Beladel, Brahim [Djelfa Univ. (Algeria)

    2015-09-01

    The present investigation was conducted to determine the chemical contents of Lygeum spartum L. (Poaceae). Samples were analyzed in order to determine essential (Ca, K, Na, Fe, Co) and some potentially toxic elements (Eu, Sb, Tb) using instrumental neutron activation analysis (INAA). In general chemical element contents were in substantial amounts to meet adult sheep requirements. Potential intake of Ca, K, Zn, Co and Fe by ruminant weighing 50 kg BW consuming 2.0 kg per day DM was sufficient to satisfy their requirements. However, only Na level was still insufficient to meet the requirements for grazing ruminants. Potential toxic elements in this species were within the safety baseline of all the assayed elements recommended by NRC. Na supplementation would seem to be necessary in this zone, for optimum productivity of grazing animals.

  14. Note: Detector collimators for the nanoscale ordered materials diffractometer instrument at the Spallation Neutron Source

    Energy Technology Data Exchange (ETDEWEB)

    Tamalonis, A. [Materials Development, Inc., Arlington Heights, Illinois 60004, USA; Weber, J. K. R. [Materials Development, Inc., Arlington Heights, Illinois 60004, USA; Argonne National Laboratory, Argonne, Illinois 60439, USA; Neuefeind, J. C. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA; Carruth, J. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA; Skinner, L. B. [Materials Development, Inc., Arlington Heights, Illinois 60004, USA; Argonne National Laboratory, Argonne, Illinois 60439, USA; Stony Brook University, Stony Brook, New York 11794, USA; Alderman, O. L. G. [Materials Development, Inc., Arlington Heights, Illinois 60004, USA; Argonne National Laboratory, Argonne, Illinois 60439, USA; Benmore, C. J. [Argonne National Laboratory, Argonne, Illinois 60439, USA

    2015-09-01

    Five neutron collimator designs were constructed and tested at the nanoscale ordered materials diffractometer (NOMAD) instrument. Collimators were made from High Density PolyEthylene (HDPE) or 5% borated HDPE. In all cases, collimators improved the signal to background ratio and reduced detection of secondary scattering. In the Q-range 10-20 (angstrom)-1, signal to background ratio improved by factors of approximately 1.6 and 2.0 for 50 and 100 mm deep collimators, respectively. In the Q-range 40-50 angstrom-1, the improvement factors were 1.8 and 2.7. Secondary scattering as measured at Q similar to 9.5 angstrom-1 was significantly decreased when the collimators were installed.

  15. Note: Detector collimators for the nanoscale ordered materials diffractometer instrument at the Spallation Neutron Source

    Energy Technology Data Exchange (ETDEWEB)

    Tamalonis, A. [Materials Development, Inc., Arlington Heights, Illinois 60004 (United States); Weber, J. K. R., E-mail: rweber@anl.gov; Alderman, O. L. G. [Materials Development, Inc., Arlington Heights, Illinois 60004 (United States); Argonne National Laboratory, Argonne, Illinois 60439 (United States); Neuefeind, J. C.; Carruth, J. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States); Skinner, L. B. [Materials Development, Inc., Arlington Heights, Illinois 60004 (United States); Argonne National Laboratory, Argonne, Illinois 60439 (United States); Stony Brook University, Stony Brook, New York 11794 (United States); Benmore, C. J. [Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2015-09-15

    Five neutron collimator designs were constructed and tested at the nanoscale ordered materials diffractometer (NOMAD) instrument. Collimators were made from High Density PolyEthylene (HDPE) or 5% borated HDPE. In all cases, collimators improved the signal to background ratio and reduced detection of secondary scattering. In the Q-range 10-20 Å{sup −1}, signal to background ratio improved by factors of approximately 1.6 and 2.0 for 50 and 100 mm deep collimators, respectively. In the Q-range 40-50 Å{sup −1}, the improvement factors were 1.8 and 2.7. Secondary scattering as measured at Q ∼ 9.5 Å{sup −1} was significantly decreased when the collimators were installed.

  16. Application of instrumental neutron activation analysis for the examination of oil pigments

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Y.S.; Kim, S.H.; Sun, G.M.; Lim, J.M.; Moon, J.H.; Kim, Y.J. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lim, S.J.; Song, Y.N.; Kim, K. [National Museum of Contemporary Art, Gwacheon, Gyeonggi-do (Korea, Republic of)

    2011-07-01

    This study is to investigate the applicability of instrumental neutron activation analysis (INAA) as a non-destructive examination tool for the quantitative chemical composition analysis associated with authentication, restoration and conservation of art objects in the field of cultural heritage. The quantitative analysis of major, minor and trace elements in Rembrandt's {sup registered} oil pigments recently collected at the Korean market as one of the art objects was carried out using INAA facilities of the HANARO research reactor at the Korea Atomic Energy Research Institute in collaboration with the National Museum of Contemporary Art in Korea. Analytical quality control was implemented using NIST SRM 2709, certified reference materials and metal standards. The analytical results for seventeen characteristic elements of thirty-one measured elements were statistically treated to identify the characteristic correlations and patterns between color and source of oil pigment and similarity degree of constituents using a cluster and discriminate analysis. (orig.)

  17. Texas Instruments TPS7H1101-SP Fast Neutron Irradiation Results

    CERN Document Server

    The ATLAS collaboration

    2015-01-01

    Texas Instruments’s TPS7H1101-SP is an ultra low drop-out voltage regulator that operates under a wide range of input voltages - 1.5 to 7V. It can operate under a load of at most 3A and is radiation qualified by Texas Instruments for Total Ionizing Dose (TID) effects and Single Event Effects (SEE). For the application of the TPS7H1101-SP on the Front End Boards (FEBs) of the New Small Wheel (NSW) of the ATLAS detector, we study its susceptibility to a third kind of radiation effect -displacement damage- and present its performance in fast neutrons up to a dose of 6 x 10$^{14}$ 1MeVNE/cm$^{2}$.

  18. Instrumental neutron activation analysis data for cloud-water particulate samples, Mount Bamboo, Taiwan

    Science.gov (United States)

    Lin, Neng-Huei; Sheu, Guey-Rong; Wetherbee, Gregory A.; Debey, Timothy M.

    2013-01-01

    Cloud water was sampled on Mount Bamboo in northern Taiwan during March 22-24, 2002. Cloud-water samples were filtered using 0.45-micron filters to remove particulate material from the water samples. Filtered particulates were analyzed by instrumental neutron activation analysis (INAA) at the U.S. Geological Survey National Reactor Facility in Denver, Colorado, in February 2012. INAA elemental composition data for the particulate materials are presented. These data complement analyses of the aqueous portion of the cloud-water samples, which were performed earlier by the Department of Atmospheric Sciences, National Central University, Taiwan. The data are intended for evaluation of atmospheric transport processes and air-pollution sources in Southeast Asia.

  19. KWS-3, the new focusing-mirror ultra small-angle neutron scattering instrument and reflectometer at Jülich

    Science.gov (United States)

    Kentzinger, E.; Dohmen, L.; Alefeld, B.; Rücker, U.; Stellbrink, J.; Ioffe, A.; Richter, D.; Brückel, Th.

    2004-07-01

    In Jülich, a new high-resolution small-angle neutron scattering (SANS) instrument and reflectometer has been built. The principle of this instrument is a one-to-one image of an entrance aperture on a 2D position-sensitive detector by neutron reflection on a double-focusing toroidal mirror. It permits to perform SANS studies with a scattering wave vector resolution between 10-3 and 10-4Å-1 with considerable intensity advantages over pinhole-SANS instruments. To date, KWS-3 is the worldwide unique SANS instrument running on this principle. We present here the characterization of the image produced by the mirror and a measurement of the scattering from a diffraction grating.

  20. Elastic Scattering Spectroscopy (ESS): an Instrument-Concept for Dynamics of Complex (Bio-) Systems From Elastic Neutron Scattering

    Science.gov (United States)

    Benedetto, Antonio; Kearley, Gordon J.

    2016-10-01

    A new type of neutron-scattering spectroscopy is presented that is designed specifically to measure dynamics in bio-systems that are difficult to obtain in any other way. The temporal information is largely model-free and is analogous to relaxation processes measured with dielectric spectroscopy, but provides additional spacial and geometric aspects of the underlying dynamics. Numerical simulations of the basic instrument design show the neutron beam can be highly focussed, giving efficiency gains that enable the use of small samples. Although we concentrate on continuous neutron sources, the extension to pulsed neutron sources is proposed, both requiring minimal data-treatment and being broadly analogous with dielectric spectroscopy, they will open the study of dynamics to new areas of biophysics.

  1. Elastic Scattering Spectroscopy (ESS): an Instrument-Concept for Dynamics of Complex (Bio-) Systems From Elastic Neutron Scattering

    Science.gov (United States)

    Benedetto, Antonio; Kearley, Gordon J.

    2016-01-01

    A new type of neutron-scattering spectroscopy is presented that is designed specifically to measure dynamics in bio-systems that are difficult to obtain in any other way. The temporal information is largely model-free and is analogous to relaxation processes measured with dielectric spectroscopy, but provides additional spacial and geometric aspects of the underlying dynamics. Numerical simulations of the basic instrument design show the neutron beam can be highly focussed, giving efficiency gains that enable the use of small samples. Although we concentrate on continuous neutron sources, the extension to pulsed neutron sources is proposed, both requiring minimal data-treatment and being broadly analogous with dielectric spectroscopy, they will open the study of dynamics to new areas of biophysics. PMID:27703184

  2. Ground tests of the Dynamic Albedo of Neutron instrument operation in the passive mode with a Martian soil model

    Science.gov (United States)

    Shvetsov, V. N.; Dubasov, P. V.; Golovin, D. V.; Kozyrev, A. S.; Krylov, A. R.; Krylov, V. A.; Litvak, M. L.; Malakhov, A. V.; Mitrofanov, I. G.; Mokrousov, M. I.; Sanin, A. B.; Timoshenko, G. N.; Vostrukhin, A. A.; Zontikov, A. O.

    2017-07-01

    The results of the Dynamic Albedo of Neutrons (DAN) instrument ground tests in the passive mode of operation are presented in comparison with the numerical calculations. These test series were conducted to support the current surface measurements of DAN onboard the MSL Curiosity rover. The instrument sensitivity to detect thin subsurface layers of water ice buried at different depths in the analog of Martian soil has been evaluated during these tests. The experiments have been done with a radioisotope Pu-Be neutron source (analog of the MMRTG neutron source onboard the Curiosity rover) and the Martian soil model assembled from silicon-rich window glass pane. Water ice layers were simulated with polyethylene sheets. All experiments have been performed at the test facility built at the Joint Institute for Nuclear Research (Dubna, Russia).

  3. Designing a minimum-functionality neutron and gamma measurement instrument with a focus on authentication

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter J [Los Alamos National Laboratory; Williams, Richard B [Los Alamos National Laboratory

    2009-01-01

    During the design and construction of the Next-Generation Attribute-Measurement System, which included a largely commercial off-the-shelf (COTS), nondestructive assay (NDA) system, we realized that commercial NDA equipment tends to include numerous features that are not required for an attribute-measurement system. Authentication of the hardware, firmware, and software in these instruments is still required, even for those features not used in this application. However, such a process adds to the complexity, cost, and time required for authentication. To avoid these added authenticat ion difficulties, we began to design NDA systems capable of performing neutron multiplicity and gamma-ray spectrometry measurements by using simplified hardware and software that avoids unused features and complexity. This paper discusses one possible approach to this design: A hardware-centric system that attempts to perform signal analysis as much as possible in the hardware. Simpler processors and minimal firmware are used because computational requirements are kept to a bare minimum. By hard-coding the majority of the device's operational parameters, we could cull large sections of flexible, configurable hardware and software found in COTS instruments, thus yielding a functional core that is more straightforward to authenticate.

  4. Beyond Californium-A Neutron Generator Alternative for Dosimetry and Instrument Calibration in the U.S.

    Science.gov (United States)

    Piper, Roman K; Mozhayev, Andrey V; Murphy, Mark K; Thompson, Alan K

    2017-09-01

    Evaluations of neutron survey instruments, area monitors, and personal dosimeters rely on reference neutron radiations, which have evolved from the heavy reliance on (α,n) sources to a shared reliance on (α,n) and the spontaneous fission neutrons of californium-252 (Cf). Capable of producing high dose equivalent rates from an almost point source geometry, the characteristics of Cf are generally more favorable when compared to the use of (α,n) and (γ,n) sources or reactor-produced reference neutron radiations. Californium-252 is typically used in two standardized configurations: unmoderated, to yield a fission energy spectrum; or with the capsule placed within a heavy-water moderating sphere to produce a softened spectrum that is generally considered more appropriate for evaluating devices used in nuclear power plant work environments. The U.S. Department of Energy Cf Loan/Lease Program, a longtime origin of affordable Cf sources for research, testing and calibration, was terminated in 2009. Since then, high-activity sources have become increasingly cost-prohibitive for laboratories that formerly benefited from that program. Neutron generators, based on the D-T and D-D fusion reactions, have become economically competitive with Cf and are recognized internationally as important calibration and test standards. Researchers from the National Institute of Standards and Technology and the Pacific Northwest National Laboratory are jointly considering the practicality and technical challenges of implementing neutron generators as calibration standards in the U.S. This article reviews the characteristics of isotope-based neutron sources, possible isotope alternatives to Cf, and the rationale behind the increasing favor of electronically generated neutron options. The evaluation of a D-T system at PNNL has revealed characteristics that must be considered in adapting generators to the task of calibration and testing where accurate determination of a dosimetric quantity is

  5. The new small-angle neutron scattering instrument SANS-1 at MLZ-characterization and first results

    Science.gov (United States)

    Mühlbauer, S.; Heinemann, A.; Wilhelm, A.; Karge, L.; Ostermann, A.; Defendi, I.; Schreyer, A.; Petry, W.; Gilles, R.

    2016-10-01

    A thorough characterization of the key features of the new small-angle neutron scattering instrument SANS-1 at MLZ, a joint project of Technische Universität München and Helmholtz Zentrum Geesthacht, is presented. Measurements of the neutron beam profile, divergency and flux are given for various positions along the instrument including the sample position, and agree well with Monte Carlo simulations of SANS-1 using the program McStas. Secondly, the polarization option of SANS-1 is characterized for a broad wavelength band. A key feature of SANS-1 is the large accessible Q-range facilitated by the sideways movement of the detector. Particular attention is hence paid to the effects that arise due to large scattering angles on the detector where a standard cos3 solid angle correction is no longer applicable. Finally the performance of the instrument is characterized by a set of standard samples.

  6. New thermal neutron prompt {gamma}-ray activation analysis instrument at the National Institute of Standards and Technology Center for Neutron Research

    Energy Technology Data Exchange (ETDEWEB)

    Mackey, E.A. E-mail: lmackey@nist.gov; Anderson, D.L.; Liposky, P.J.; Lindstrom, R.M.; Chen-Mayer, H.; Lamaze, G.P

    2004-11-01

    A new thermal neutron prompt {gamma}-ray activation analysis (PGAA) instrument was designed and built to replace the original PGAA system at the NIST Center for Neutron Research. By placing a sapphire filter in the neutron beam shutter assembly, the fast neutron fluence rate was reduced by a factor of 5 and low-energy (50-200 keV) {gamma}-ray intensities were reduced by factors of 5-10. The thermal neutron fluence rate was reduced by only a factor of 1.13. A new external beam tube, sample chamber, beam stop, and support structure were built and a new detection system installed. The new beam tube is made of two cylindrical aluminum sections lined with a lithiated polymer. Both sections are kept under vacuum to reduce the number of neutrons scattered by air into the beam tube walls. The sample chamber is also fabricated from aluminum and lined with lithiated polymer, and may be evacuated to minimize the number of neutrons scattered and absorbed by air. The beam tube and sample chamber assembly is suspended from the aluminum support structure. The detection system consists of a 40% efficient (relative) germanium detector (resolution 2.0 at 1332.5 keV) and a bismuth germanate Compton suppressor. The detection system is shielded by lead, surrounded by borated and lithiated polyethylene, and placed on a table attached to the support structure. The new, more compact beam stop is welded to the support structure. Capture {gamma}-ray photopeaks from H, B, C, N, Na, Al, Fe, Ge, I and Pb in the background spectrum were either of lower intensity or eliminated with the new PGAA instrument. The more efficient detection system, positioned closer to the sample, yielded element sensitivity increases of 5-50%. Limits of detection have been greatly reduced compared with those of the original instrument due to reduced Compton and scattered {gamma}-ray backgrounds (especially in the low-energy region), increased sensitivities, and reduction of background {gamma}-ray photopeak

  7. Monte Carlo simulations for the development of polarized neutron instrumentation: An overview

    Science.gov (United States)

    Zsigmond, Geza; Manoshin, Sergey; Lieutenant, Klaus; Seeger, Philip A.; Christiansen, Peter; Willendrup, Peter; Lefmann, Kim

    2007-07-01

    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 contains polarization tools. McStas has implemented an initial set of routines handling polarization, as our examples will also show.

  8. Monte Carlo simulations for the development of polarized neutron instrumentation: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Zsigmond, Geza [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)]. E-mail: geza.zsigmond@psi.ch; Manoshin, Sergey [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Lieutenant, Klaus [Institute for Energy Technology, NO-2007 Kjeller (Norway); Seeger, Philip A. [239 Loma del Escolar, Los Alamos, NM (United States); Christiansen, Peter [Materials Research Department, Riso National Laboratory (Denmark); Willendrup, Peter [Materials Research Department, Riso National Laboratory (Denmark); Lefmann, Kim [Materials Research Department, Riso National Laboratory (Denmark)

    2007-07-15

    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 contains polarization tools. McStas has implemented an initial set of routines handling polarization, as our examples will also show.

  9. Measurements on High-Silica Features using the Dynamic Albedo of Neutrons Instrument on the Mars Science Laboratory Curiosity Rover

    Science.gov (United States)

    Hardgrove, C. J.; Gabriel, T. S. J.

    2016-12-01

    The Mars Science Laboratory (MSL) Curiosity rover has traversed over several plateaus of the Stimson formation, composed of mafic aeolian sandstones which overlie the Murray formation. These dark sedimentary rocks exhibit lighter colored fluid-alteration halo-forming features. Throughout the Naukluft Plateau region, these halo features are exposed at the surface, extend laterally for tens of meters and are about 1 meter wide. The halos were investigated extensively by Curiosity's geochemical instruments (APXS, Chemin, Chemcam and SAM). With respect to the host Stimson rocks, these fracture halos were found to be significantly enriched in silica and low in iron, among other geochemical variations. Hydrogen, chlorine, and iron have significant neutron microscopic scattering and absorption cross sections. Significant changes in the local abundances of these elements will change the timing and magnitude of the thermal and epithermal neutron count rates observed by the Dynamic Albedo of Neutrons (DAN) instrument. On Sols 1316 to 1329 we performed dedicated measurements on these features with Curiosity by orienting the rover such that DAN was directly over the fracture halos. These fracture halos were also investigated by Curiosity's other geochemical instruments, and co-located DAN measurements were acquired to help constrain abundances of these elements at decimeter-scale depths. Using the bulk geochemistry for both the altered and unaltered Stimson formation, we model a variety of hydrogen contents and burial depths for the altered and unaltered Stimson formation within the approximately 3 meter diameter DAN instrument field of view. Measurements of chemical abundances from both the Alpha Particle X-ray Spectrometer and the Sample Analysis at Mars instrument suite on targets "Lubango" and "Okoruso" provide necessary constraints on these models. Using simulations of neutron scattering we then outline the abundances of hydrogen, chlorine, and iron at depth at the

  10. System of adjoint P1 equations for neutron moderation; Sistema de equacoes P1 adjuntas para a moderacao de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Aquilino Senra; Silva, Fernando Carvalho da; Cardoso, Carlos Eduardo Santos [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear

    2000-07-01

    In some applications of perturbation theory, it is necessary know the adjoint neutron flux, which is obtained by the solution of adjoint neutron diffusion equation. However, the multigroup constants used for this are weighted in only the direct neutron flux, from the solution of direct P1 equations. In this work, this procedure is questioned and the adjoint P1 equations are derived by the neutron transport equation, the reversion operators rules and analogies between direct and adjoint parameters. (author)

  11. Soil pollution with trace elements at selected sites in Romania studied by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Pantelica, A. [Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), Magurele, Ilfov County (Romania); Carmo Freitas, M. do [Technological and Nuclear Institute (ITN), Sacavem (Portugal); Ene, A. [Dunarea de Jos Univ. of Galati (Romania). Dept. of Chemistry, Physics and Environment; Steinnes, E. [Norwegian Univ. of Science and Technology, Trondheim (Norway). Dept. of Chemistry

    2013-03-01

    Instrumental neutron activation analysis (INAA) was used to determine concentrations of 42 elements in samples of surface soil collected at seven sites polluted from various anthropogenic activities and a control site in a relatively clean area. Elements studied were Ag, Al, As, Au, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Eu, Fe, Gd, Hf, Hg, K, La, Lu, Mg, Mn, Mo, Na, Nd, Ni, Rb, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, Ti, U, V, W, Yb, Zn, and Zr. The results are compared with data for trace elements atmospheric deposition in lichen transplants from the same sites. The most severe soil contamination was observed at Copsa Mica from non-ferrous metallurgy. Appreciable soil contamination was also indicated at Baia Mare (non-ferrous mining and metallurgy), Deva (coal-fired power plant, cement and building materials industry), Galati (ferrous metallurgy), Magurele and Afumati (general urban pollution), and Oradea (chemical and light industries). In most cases excessive levels of toxic metals in soils matched correspondingly high values in lichen transplants. Compared to Romanian norms, legal upper limits were exceeded for Zn and Cd at Copsa Mica. Also, As and Sb occurred in excessive levels at given sites. (orig.)

  12. Neutron scattering instruments for residual stress/strain measurements at KUR

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Masayoshi [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

    1997-06-01

    A Kyoto University Reactor project research finished on March, 1997 is a first trial in Japan. In this research, some residual stress measurement in accompany with thermal and processing deformation history of various superconductive composite wires and so on were conducted to obtain a lot of research results. At TOF system, simultaneous measurement of the direction dependent collective texture using a multi point detector was useful, and at PSD system the strain measurement in a region under 10{sup -4} became possible to conduct. In addition, it is intending now to establish high performance instruments such as a two-stage type disc chopper at the TOF system and a high resolution vent type Si monocrystal monochromator at the PSD system. In particular, it is expected a the TOF system that a direction dependent collective texture and a stress distribution state in various kinds of functional materials can be measured simultaneously and without destruction. The mechanical property research of the metallic materials using low speed neutron scattering method is now a big interest in and out of Japan. This research contains a lot of contents coinciding to the industrial fields in an application research field of nuclear basic research and is expected in future to powerfully promote international cooperative research and to deeply recognize its usefulness and importance. (G.K.)

  13. Determination of essential elements in commercial infant foods by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vallinoto, Priscila; Maihara, Vera A., E-mail: pvallinoto@ipen.br, E-mail: vmaihara@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Eating habits are important determinants of health conditions during childhood. Commercial infant food is an important part of the diet for many babies. As such it is necessary that such food contain sufficient amounts of essential elements. Inadequate complementary feeding is a major cause of high rates of malnutrition throughout the world. Commercial infant food is classified into four different stages: Stages 1 and 2 are adequate for babies older than 6 months, but new flavors and food are introduced in stage 2; Stage 3 is offered to 8 month old babies; Junior Stage is recommended to children over 1 year old. In this study, essential elements: Ca, Cl, Co, Cr, Fe K, Mg, Mn, Na, Se and Zn were determined in commercial infant food samples by Instrumental Neutron Activation Analysis (INAA). Twenty-seven infant food samples were bought in stores around Sao Paulo city during 2011. These samples were freeze-dried and homogenized before analysis. The powdered samples were irradiated in the IEA-R1 nuclear research reactor of IPEN-CNEN/SP. For validation of the methodology, INCT MPH-2 Mixed Polish Herbs and NIST-SRM 1577b Bovine Liver reference materials were analyzed. Most of the concentration results were below the World Health Organization's recommended daily intake for infants from 6 to 12 months old. These low essential element concentration results in commercial infant foods obtained in our study indicate that infants should not only be fed with commercial baby foods. (author)

  14. Elemental Composition of Different Slovenian Honeys Using k0- Instrumental Neutron Activation Analysis.

    Science.gov (United States)

    Kropf, Urška; Stibilj, Vekoslava; Jaćimović, Radojko; Bertoncelj, Jasna; Golob, Terezija; Korošec, Mojca

    2017-07-01

    The botanical origin of seven types of Slovenian honey was investigated by analysis of their elemental content using k0-instrumental neutron activation analysis. A total of 28 representative samples were collected from beekeepers all over Slovenia in 2 consecutive years. Nineteen of the 37 elements measured were present in amounts above their LOD. The present study suggests that the determination of only alkali elements might be sufficient for the classification of Slovenian honeys according to their botanical origin. Linden and multifloral honeys can be differentiated on the basis of Na content. The differentiation of forest, spruce, and fir honeys is possible on the basis of differences in Cs, K, and Rb content. The difference between Na and Rb content can be used as a discriminating tool between light and dark honeys, because light honeys (black locust, linden, and multifloral) contained more Na than Rb, whereas it was the opposite for dark honeys (chestnut, forest, spruce, and fir). Statistically significant correlations were found between K and Rb and between K and Cs content. This study represents a considerable step in filling the knowledge gap concerning both the determination of elements present in low concentrations and the botanical origin of Slovenian honey.

  15. Instrumental Neutron Activation Analysis of Trace Elements in Some Food Spices Consumed In Tehran, Iran

    Directory of Open Access Journals (Sweden)

    ali asghar fathivand

    2017-03-01

    Full Text Available Introduction There is a growing interest in determining the concentration of various elements in food spices. In the present study, the instrumental neutron activation analysis (INAA was employed to measure the trace elements in 11 commonly food spices consumed in Tehran, Iran. Materials and Methods The levels of K, Mn, Na, Cl, V, Br, Al, and As were determined and their effects on human health were discussed. The results were compared with the values reported in the literature. The accuracy and precision of the analytical procedure was estimated by analyzing the Lichen (IAEA-336 reference material. Results The concentrations of the measured elements in the spices were 3850-29157, 10-335, 153-2849, 186-3063, 0.2-2.8, 2.1-58.7, and 72-2102 ppm for K, Mn, Na, Cl, V, Br, and Al, respectively. As was only detected in thyme (0.8 ppm and plantain (0.42 ppm. Conclusion As the findings of the present study indicated, the concentrations of K and Na in the black pepper, garlic, and ginger were significantly higher than the values reported in other countries. The Mn levels in the black pepper and garlic consumed in Tehran were comparable with those in Poland. Furthermore, the concentration of As in these spices were lower than the maximum permissible limit.

  16. Fracture behaviors of neutron-irradiated ferritic steels studied by the instrumented charpy impact test

    Science.gov (United States)

    Yoshida, H.; Miyata, K.; Narui, M.; Kayano, H.

    1989-12-01

    The instrumented Charpy impact test for quarter-size specimens was developed and applied to study fracture behavior of ferritic steels and a ferritic-martensitic steel (JFMS) before and after neutron irradiation. The load-deflection curves obtained for U- and V-notched specimens showed typical characteristics of fracture properties of these steels. The temperature dependence of the fracture energy ( Ef) and the failure deflection ( Df) clearly indicates ductile-brittle transition and the DBTT can be determined from the Ef and Df versus temperature curves. The V-notched specimens showed sharper transition at higher temperatures for the JFMS than the U-notched ones, where the former were sensitive to brittle fracture and the latter well demonstrated the behavior of crack propagation. For the ferritic steels the DBTTs showed low values at compositions containing approximate 8-10% Cr and the increase of the DBTT (Δ DBTT) due to irradiation also showed a similar tendency. The Δ DBTT appeared to be relatively larger for the JFMS than the ferritic steels.

  17. Analysis of Essential Elements for Plants Growth Using Instrumental Neutron Activation Analysis

    Directory of Open Access Journals (Sweden)

    R. L. Njinga

    2013-01-01

    Full Text Available In this study, a total of ten essential elements for plants growth in the Guinea savanna region of Niger State in Northern Nigeria have been identified in the soils using instrumental neutron activation analysis. The experimental results show good agreement with certified or literature values within the agreed percentage range of ±2.35% to ±8.69%. However, the concentration distributions of the ten identified elements in the soil samples within the studied area for plants growth revealed the following: Fe (123.4 ppm, Mn (2100.7 ppm, K (5544.3 ppm, Al (54752.4 ppm, Ti (3082.9 ppm, Ca (4635 ppm, V (54.3 ppm, Na (857.5 ppm, Mg (13924.1 ppm, and Dy (12.1 ppm. A further analysis of the two fundamental soil physical parameters for healthy growth of some common crops like egusimelon, groundnut, rice, yams, soybeans, cassava, and potato analyzed in this work revealed a pH range of 4.0 pH–8.0 pH and a temperature range of 28.0°C to 29.3°C, which are optimal for plant nutrients availability in the soils within the study area.

  18. Determination of zinc concentration in female reproductive system by instrumental neutron activation

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Fernando Ramos de, E-mail: framosc@oi.com.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear; Oliveira, Arno Heeren de, E-mail: heeren@nuclear.ufmg.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Faculdade de Medicina. Dept. de Ginecologia e Obstetricia; Ferreira, Claudia R.C.; Ferreira, Ricardo Alberto Neto; Menezes, Maria Angela de B.C., E-mail: claudia@medicina.ufmg.b, E-mail: ranf@cdtn.b, E-mail: menezes@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2009-07-01

    Non-surgical female sterilization through the transcervical insertion of quinacrine pellets was considered a definitive, low-cost, safe and effective contraceptive method. The zinc, present in both uterus and Fallopian tubes, inhibit the quinacrine efficiency. The addition of copper increases the efficacy of quinacrine, reducing the risk of pregnancy due to the failure to obstruct the Fallopian tubes. The copper neutralized the deleterious effect of the zinc and so the treatment efficacy is increased. In order to obtain a mapping to study the zinc content in the female reproductive system, samples of both uterus and Fallopian tubes were analyzed by instrumental neutron activation. The results show that, on average, the obtained zinc concentrations in tubes (89 mug-g{sup -1}) is lower than in the uterus (118 mug-g{sup -1}), confirming results obtained by other authors. These results will support a research project about non-surgical female sterilization of the 'Faculdade de Medicina da Universidade Federal de Minas Gerais' (Medical School of Federal University of Minas Gerais). The used methodology and obtained results are here reported. (author)

  19. Use of Instrumental Neutron Activation Analysis to investigate the distribution of trace elements among subsamples of solid materials

    CERN Document Server

    DAgostino, Giancarlo; Giordani, Laura; Oddone, Massimo; Kipphardt, Heinrich; Richter, Silke

    2013-01-01

    The results of analytical measurements performed with solid-sampling techniques are affected by the distribution of the analytes within the matrix. The effect becomes significant in case of determination of trace elements in small subsamples. In this framework we propose a measurement model based on Instrumental Neutron Activation Analysis to determine the relative variability of the amount of an analyte among subsamples of a material. The measurement uncertainty is evaluated and includes the counting statistics, the full-energy gamma peak efficiency and the spatial gradient of the neutron flux at the irradiation position. The data we obtained in a neutron activation experiment and showing the relative variability of As, Au, Ir, Sb and W among subsamples of a highly pure Rh foil are also presented.

  20. Integration of a $^6$LiInSe$_2$ Thermal Neutron Detector into a CubeSat Instrument

    CERN Document Server

    Egner, Joanna C; Burger, Arnold; Stassun, Keivan G; Buliga, Vladimir; Matei, Liviu; Bodnarik, Julia G; Stowe, Ashley C; Prettyman, Thomas H

    2016-01-01

    We present a preliminary design for a novel neutron detection system that is compact, lightweight, and low power consuming, utilizing the CubeSat platform making it suitable for space-based applications. This is made possible using the scintillating crystal lithium indium diselenide ($^6$LiInSe$_2$), the first crystal to include $^6$Li in the crystalline structure, and a silicon avalanche photodiode (Si-APD). The schematics of this instrument are presented as well as the response of the instrument to initial testing under alpha radiation. A principal aim of this work is to demonstrate the feasibility of such a neutron detection system within a CubeSat platform. The entire end-to-end system presented here is 10 cm x 10 cm x 15 cm, weighs 670 grams and requires 5 Volts direct current at 3 Watts.

  1. Elemental analysis using instrumental neutron activation analysis and inductively coupled plasma atomic emission spectrometry: a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong Sam; Choi, Kwang Soon; Moon, Jong Hwa; Kim, Sun Ha; Lim, Jong Myoung; Kim, Young Jin [KAERI, Taejon (Korea, Republic of); Quraishi, Shamshad Begum [Bangladesh Atomic Energy Commission, Dhaka (Bangladesh)

    2003-05-01

    Elemental analyses for certified reference materials were carried out using instrumental neutron activation analysis and inductively coupled plasma-atomic emission spectrometry. Five Certified Reference Materials (CRM) were selected for the study on comparative analysis of environmental samples. The CRM are Soil (NIST SRM 2709), Coal fly ash (NIST SRM 1633a), urban dust (NIST SRM 1649a) and air particulate on filter media (NIST SRM 2783 and human hair (GBW 09101)

  2. GEANIE at WNR/LANSCE -- A new instrument for neutron science

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, R.O.; Becker, J.A.; Archer, D.E. [and others

    1997-09-01

    GEANIE, an array of escape-suppressed high-resolution Ge detectors now installed at the white-neutron source at the Los Alamos Neutron Science Center, is the first large Ge detector array to be used at a high-energy spallation neutron source. GEANIE consists of 20 Ge detectors including both coaxial Ge detectors and planar Ge detectors to enhance capabilities for low-energy {gamma}-ray spectroscopy. The array is located on a 20 m flight path with a neutron flux spanning the energy range from 1 to over 200 MeV. Installation of the first phase of GEANIE was recently completed and data were acquired on a number of samples, including actinides. The unique combination of GEANIE with the neutron source at LANSCE provides new capabilities for neutron science. The status of the array and recent results are presented, and new opportunities for physics and nuclear data are discussed.

  3. Exploring the structure of biological macromolecules in solution using Quokka, the small angle neutron scattering instrument, at ANSTO

    Science.gov (United States)

    Wood, Kathleen; Jeffries, Cy M.; Knott, Robert B.; Sokolova, Anna; Jacques, David A.; Duff, Anthony P.

    2015-10-01

    Small angle neutron scattering (SANS) is widely used to extract structural parameters, shape and other types of information from a vast array of materials. The technique is applied to biological macromolecules and their complexes in solution to reveal information often not accessible by other techniques. SANS measurements on biomolecules present some particular challenges however, one of which is suitable instrumentation. This review details SANS experiments performed on two well-characterised globular proteins (lysozyme and glucose isomerase) using Quokka, the recently commissioned SANS instrument at the Australian Nuclear Science and Technology Organisation (ANSTO). The instrument configuration as well as data collection and reduction strategies for biological investigations are discussed and act as a general reference for structural biologists who use the instrument. Both model independent analysis of the two proteins and ab initio modelling illustrate that Quokka-SANS data can be used to successfully model the overall shapes of proteins in solution, providing a benchmark for users.

  4. Exploring the structure of biological macromolecules in solution using Quokka, the small angle neutron scattering instrument, at ANSTO

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Kathleen, E-mail: kw@ansto.gov.au [Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, NSW 2234 (Australia); Jeffries, Cy M.; Knott, Robert B.; Sokolova, Anna [Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, NSW 2234 (Australia); Jacques, David A. [MRC Laboratory of Molecular Biology, Cambridge (United Kingdom); Duff, Anthony P. [Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, NSW 2234 (Australia)

    2015-10-21

    Small angle neutron scattering (SANS) is widely used to extract structural parameters, shape and other types of information from a vast array of materials. The technique is applied to biological macromolecules and their complexes in solution to reveal information often not accessible by other techniques. SANS measurements on biomolecules present some particular challenges however, one of which is suitable instrumentation. This review details SANS experiments performed on two well-characterised globular proteins (lysozyme and glucose isomerase) using Quokka, the recently commissioned SANS instrument at the Australian Nuclear Science and Technology Organisation (ANSTO). The instrument configuration as well as data collection and reduction strategies for biological investigations are discussed and act as a general reference for structural biologists who use the instrument. Both model independent analysis of the two proteins and ab initio modelling illustrate that Quokka-SANS data can be used to successfully model the overall shapes of proteins in solution, providing a benchmark for users.

  5. Maximum Alpha to Minimum Fission Pulse Amplitude for a Parallel-Plate and Hemispherical Cf-252 Ion-Chamber Instrumented Neutron Source

    Energy Technology Data Exchange (ETDEWEB)

    Oberer, R.B.

    2000-12-07

    In an instrumented Cf-252 neutron source, it is desirable to distinguish fission events which produce neutrons from alpha decay events. A comparison of the maximum amplitude of a pulse from an alpha decay with the minimum amplitude of a fission pulse shows that the hemispherical configuration of the ion chamber is superior to the parallel-plate ion chamber.

  6. Characteristic Elemental Composition of Oil Pigments using Instrumental Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong Sam; Kim, Sun Ha; Sun, Gwang Min; Lim, Jong Myung; Moon, Jong Hwa; Kim, Young Jin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lim, Sung Jin; Song, Yu Na; Kim, Ken [National Museum of Contemporary Art, Gwacheon (Korea, Republic of)

    2009-10-15

    The principal aim of this study is to identify the applicability of instrumental neutron activation analysis as a non-destructive examination tool for the quantitative composition analysis associated with authentication, restoration, and conservation of art objects in the field of cultural heritage. Generally, the chemical composition of pigments are associated with the colors such as white, yellow, orange, red, green, blue and black, and it varies with raw materials of pigments. According to the colors of a different pigments, chemical compositions are as follows; for example, white pigments were used for a mixture of Pb(CO{sub 3}){sub 2}, PbSO{sub 4}, PbO, Pb(OH){sub 2}, ZnO, ZnS, TiO{sub 2}, BaSO{sub 4}, CaCO{sub 3}, Al{sub 2}O{sub 3}, As{sub 2}S{sub 3}, etc.; black pigments were series of carbon black, borne ash, MnO+Mn{sub 2}O{sub 3}, etc.; red pigments were Fe{sub 2}O{sub 3}, Pb{sub 3}O{sub 4}, HgS, PbMo{sub 4}, CdS+CdSe, etc.; brown and yellow pigments were PbCrO{sub 4}, ZnCrO{sub 4}, CdS-ZnS, K{sub 3}[Co(NO{sub 2}){sub 6}], Pb(SbO{sub 3}){sub 2}, C{sub 19}H{sub 16}O{sub 11}Mg, SrCrO{sub 4}, etc.; green pigments were Cr{sub 2}O{sub 3}, Cr{sub 2}O(OH){sub 4}, Cu(C{sub 2}H{sub 3}O{sub 2})-2Cu(OH){sub 2}), Cr{sub 2}O{sub 3}-Al{sub 2}O{sub 3}-CoO, etc.; blue pigments were Fe{sub 4}[Fe(CN){sub 6}]{sub 3}, CoO-Al{sub 2}O{sub 3}, Na{sub 8}-{sub 10}Al{sub 6}Si{sub 6}O{sub 24}S{sub 2-4}, etc. This first step is to obtain quantitative data on the concentrations of major, minor and trace elements in oil pigments and to explain pigment sources by statistical treatment as reported in many literatures. The determination of major, minor and micro elements in the subject materials are essential in many fields of basic science and technology as well as commercial and industrial fields. In particular, direct analysis of a sample offers a more effective investigation method in these fields. Instrumental neutron activation analysis (INAA) has an inherent advantage of being a

  7. Desarrollo de un prototipo de banco de pruebas para instrumental aeronáutico

    OpenAIRE

    Acosta, Nelson; Tosini, Marcelo Alejandro; Marone, José A.; Tommasi, M. Carolina

    2005-01-01

    El trabajo propone la construcción de un prototipo implementado en software y hardware asociado que reemplace la funcionalidad de un banco de pruebas de instrumental existente. Dicho instrumental, usado comúnente en equipos aéreos y navales, es de alta precisión y requiere para su reparación o mantenimiento de bancos de trabajo especializados, cuyo manejo implica gran especialización del operario y largos tiempos de proceso. Con el desarrollo propuesto se busca la minimización de la probabili...

  8. Fast determination of impurities in metallurgical grade silicon for photovoltaics by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hampel, J., E-mail: jonathan.hampel@ise.fraunhofer.de [Fraunhofer Institute for Solar Energy Systems, Heidenhofstrasse 2, D-79110 Freiburg (Germany); Boldt, F.M. [Fraunhofer Institute for Solar Energy Systems, Heidenhofstrasse 2, D-79110 Freiburg (Germany); Gerstenberg, H. [ZWE FRM-II der Technischen Universitaet Muenchen, D-85748 Garching (Germany); Hampel, G.; Kratz, J.V. [Institute of Nuclear Chemistry, Johannes Gutenberg-University of Mainz, Fritz-Strassmann-Weg 2, D-55128 Mainz (Germany); Reber, S. [Fraunhofer Institute for Solar Energy Systems, Heidenhofstrasse 2, D-79110 Freiburg (Germany); Wiehl, N. [Institute of Nuclear Chemistry, Johannes Gutenberg-University of Mainz, Fritz-Strassmann-Weg 2, D-55128 Mainz (Germany)

    2011-10-15

    Standard wafer solar cells are made of near-semiconductor quality silicon. This high quality material makes up a significant part of the total costs of a solar module. Therefore, new concepts with less expensive so called solar grade silicon directly based on physiochemically upgraded metallurgical grade silicon are investigated. Metallurgical grade silicon contains large amounts of impurities, mainly transition metals like Fe, Cr, Mn, and Co, which degrade the minority carrier lifetime and thus the solar cell efficiency. A major reduction of the transition metal content occurs during the unidirectional crystallization due to the low segregation coefficient between the solid and liquid phase. A further reduction of the impurity level has to be done by gettering procedures applied to the silicon wafers. The efficiency of such cleaning procedures of metallurgical grade silicon is studied by instrumental neutron activation analysis (INAA). Small sized silicon wafers of approximately 200 mg with and without gettering step were analyzed. To accelerate the detection of transition metals in a crystallized silicon ingot, experiments of scanning whole vertical silicon columns with a diameter of approximately 1 cm by gamma spectroscopy were carried out. It was demonstrated that impurity profiles can be obtained in a comparably short time. Relatively constant transition metal ratios were found throughout an entire silicon ingot. This led to the conclusion that the determination of several metal profiles might be possible by the detection of only one 'leading element'. As the determination of Mn in silicon can be done quite fast compared to elements like Fe, Cr, and Co, it could be used as a rough marker for the overall metal concentration level. Thus, a fast way to determine impurities in photovoltaic silicon material is demonstrated. - Highlights: > We demonstrate a fast way to determine impurities in photovoltaic silicon by NAA. > We make first experiments of

  9. Dynamics of elements in soil treated with increasing doses sewage sludge for instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Helder de; Mortatti, Jefferson; Vendramini, Diego; Lopes, Renato A.; Nolasco, Murilo M. [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Isotopos Estaveis]. E-mail: helder@cena.usp.br; Sarries, Gabriel A. [Escola Superior de Agricultura ' Luiz de Queiroz' (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Ciencias Exatas]. E-mail: gabriel@carpa.ciagri.usp.br; Furlan, Adriana [UNESP, Rio Claro, SP (Brazil). Inst. de Geociencias e Ciencias Exatas. Dept. de Petrologia e Metalogenia]. E-mail: adriana_furlangumiere@yahoo.com.br

    2007-07-01

    In this work the dynamics of the elements was analyzed The, Br, Ce, Co, Cr, Cs, Fe, Hf, La, In the, Sb, Sc, Sm, Ta, Th, U, Yb and Zn in a profile of a red-yellow latossolo, in the depths of 0-5, 5-10, 10-30 and 30-50 cm, and dose of the biosolid of 0, 25, 124 and 375 t ha{sup -1}, of the station of treatment of sewer of Barueri, Sao Paulo. The experiment was carried out in areas of 3,05 m{sup 2} in the times of 2,2; 4,0; 6,6; 14,3 and 21 months. For analysis of the elementary composition, it was used of the analysis technique by instrumental neutron activation analysis (INAA). The experiment was submitted under normal tropical conditions in a forest station in Itatinga, Sao Paulo, of the University of Sao Paulo. For better details, the factors depth, doses and times statistical analyses of the results of the elementary composition of the soil samples were made. For all the biossolid doses conditioned with polymeric and applied in the soil, the composition of 17 of the 18 elements in the soil were not altered, with exception for Cr in the studied times. The elements As, Br, Ce, Co, Fe, Hf, La, Sm, Ta, Th, U and Yb presented higher levels in the deepest layers of soil; already the elements Cr, In the, Sb and Zn presented higher concentrations in the superficial layers. (author)

  10. Comparison of the performance of different instruments in the stray neutron field around the CERN Proton Synchrotron.

    Science.gov (United States)

    Aza, Eleni; Caresana, Marco; Cassell, Christopher; Colombo, Valeria; Damjanovic, Sanja; Gilardoni, Simone; Manessi, Giacomo Paolo; Pangallo, Michel; Perrin, Daniel; Silari, Marco

    2014-10-01

    This paper discusses an intercomparison campaign carried out in several locations around the CERN Proton Synchrotron. The locations were selected in order to perform the measurements in different stray field conditions. Various neutron detectors were employed: ionisation chambers, conventional and extended range rem counters, both commercial and prototype ones, including a novel instrument called LUPIN, specifically conceived to work in pulsed fields. The attention was focused on the potential differences in the instrument readings due to dead-time losses that are expected to affect most commercial units. The results show that the ionisation chambers and LUPIN agree well with the expected H*(10) values, as derived from FLUKA simulations, showing no relevant underestimations even in strongly pulsed fields. On the contrary, the dead-time losses of the other rem counters induced an underestimation in pulsed fields that was more important for instruments characterised by a higher dead time.

  11. Solar gamma-ray and neutron registration capabilities of the GRIS instrument onboard the International Space Station

    Science.gov (United States)

    Trofimov, Yury; Kochemasov, Alexey; Yurov, Vitaly; Glyanenko, Alexander; Kotov, Yury; Lupar, Evgeny; Faradzhaev, Rodion

    2016-07-01

    GRIS (Gamma and Roentgen radiation of the Sun) is a prospective hard X-ray and gamma-ray spectrometer of solar flares with the energy range from 50 keV to 200 MeV. It is also designed for registration of high energy neutron fluxes (>30 MeV). The apparatus will be mounted on an oriented platform outside the Russian Orbital Segment of the International Space Station. The instrument includes two detector heads: a low energy spectrometer (LES) based on a fast scintillator with relatively high energy resolution 3.5-4.5% at 662 keV (LaBr _{3}(Ce) or CeBr _{3}) and size of ø7.62×7.62 cm, and a high energy spectrometer (HES) based on ø12×15 cm CsI(Tl) scintillator. Thanks to n/γ discrimination capability of CsI(Tl) crystals, the HES spectrometer is also intended for neutron registration. To estimate GRIS instrument registration capabilities, simulation of the HES neutron and gamma registration channels response to background radiation and to solar flares of different magnitude and spectral compositions was performed. Expected spectral and n/γ discrimination performances based on measurements with detectors prototypes are represented.

  12. A database of neutron spectra, instrument response functions, and dosimetric conversion factors for radiation protection applications

    Energy Technology Data Exchange (ETDEWEB)

    Naismith, O.F. [National Physical Lab., Teddington (United Kingdom); Siebert, B.R.L. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)

    1997-09-01

    One of the major problems encountered in dose assessment for neutron radiation protection derives from the imperfect dose equivalent response of the devices used for monitoring. To investigate the performance of such devices in realistic neutron fields and to optimise calibration procedures, knowledge of both the prevalent spectral fluences and the energy response of the dosemeters is required. To facilitate this and similar studies, a database has been developed comprising a catalogue of neutron spectra and energy-dependent response functions together with a software package to manipulate the data in the catalogue. The range of data, features of the programs, and examples for radiation protection applications are described. (author).

  13. Flux and instrumentation upgrade for the epithermal neutron beam facility at Washington State University.

    Science.gov (United States)

    Nigg, D W; Venhuizen, J R; Wemple, C A; Tripard, G E; Sharp, S; Fox, K

    2004-11-01

    An epithermal neutron beam facility for preclinical neutron capture therapy research has been constructed at the Washington State University TRIGA research reactor installation. Subsequent to a recent upgrade, this new facility offers a high-purity epithermal beam with intensity on the order of 1.2x10(9)n/cm(2)s. Key features include a fluoride-based design for the neutron filtering and moderating components as well as a novel collimator design that allows ease of assembly and disassembly of the beamline components.

  14. Derivation of a volume-averaged neutron diffusion equation; Atomos para el desarrollo de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez R, R.; Espinosa P, G. [UAM-Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, Mexico D.F. 09340 (Mexico); Morales S, Jaime B. [UNAM, Laboratorio de Analisis en Ingenieria de Reactores Nucleares, Paseo Cuauhnahuac 8532, Jiutepec, Morelos 62550 (Mexico)]. e-mail: rvr@xanum.uam.mx

    2008-07-01

    This paper presents a general theoretical analysis of the problem of neutron motion in a nuclear reactor, where large variations on neutron cross sections normally preclude the use of the classical neutron diffusion equation. A volume-averaged neutron diffusion equation is derived which includes correction terms to diffusion and nuclear reaction effects. A method is presented to determine closure-relationships for the volume-averaged neutron diffusion equation (e.g., effective neutron diffusivity). In order to describe the distribution of neutrons in a highly heterogeneous configuration, it was necessary to extend the classical neutron diffusion equation. Thus, the volume averaged diffusion equation include two corrections factor: the first correction is related with the absorption process of the neutron and the second correction is a contribution to the neutron diffusion, both parameters are related to neutron effects on the interface of a heterogeneous configuration. (Author)

  15. (30)Si mole fraction of a silicon material highly enriched in (28)Si determined by instrumental neutron activation analysis.

    Science.gov (United States)

    D'Agostino, Giancarlo; Di Luzio, Marco; Mana, Giovanni; Oddone, Massimo; Pramann, Axel; Prata, Michele

    2015-06-01

    The latest determination of the Avogadro constant, carried out by counting the atoms in a pure silicon crystal highly enriched in (28)Si, reached the target 2 × 10(-8) relative uncertainty required for the redefinition of the kilogram based on the Planck constant. The knowledge of the isotopic composition of the enriched silicon material is central; it is measured by isotope dilution mass spectrometry. In this work, an independent estimate of the (30)Si mole fraction was obtained by applying a relative measurement protocol based on Instrumental Neutron Activation Analysis. The amount of (30)Si isotope was determined by counting the 1266.1 keV γ-photons emitted during the radioactive decay of the radioisotope (31)Si produced via the neutron capture reaction (30)Si(n,γ)(31)Si. The x((30)Si) = 1.043(19) × 10(-6) mol mol(-1) is consistent with the value currently adopted by the International Avogadro Coordination.

  16. Pressure/temperature fluid cell apparatus for the neutron powder diffractometer instrument: probing atomic structure in situ.

    Science.gov (United States)

    Wang, Hsiu-Wen; Fanelli, Victor R; Reiche, Helmut M; Larson, Eric; Taylor, Mark A; Xu, Hongwu; Zhu, Jinlong; Siewenie, Joan; Page, Katharine

    2014-12-01

    This contribution describes a new local structure compatible gas/liquid cell apparatus for probing disordered materials at high pressures and variable temperatures in the Neutron Powder Diffraction instrument at the Lujan Neutron Scattering Center, Los Alamos National Laboratory. The new sample environment offers choices for sample canister thickness and canister material type. Finite element modeling is utilized to establish maximum allowable working pressures of 414 MPa at 15 K and 121 MPa at 600 K. High quality atomic pair distribution function data extraction and modeling have been demonstrated for a calibration standard (Si powder) and for supercritical and subcritical CO2 measurements. The new sample environment was designed to specifically target experimental studies of the local atomic structures involved in geologic CO2 sequestration, but will be equally applicable to a wide variety of energy applications, including sorption of fluids on nano/meso-porous solids, clathrate hydrate formation, catalysis, carbon capture, and H2 and natural gas uptake/storage.

  17. 30Si Mole Fraction of a Silicon Material Highly Enriched in 28Si Determined by Instrumental Neutron Activation Analysis

    CERN Document Server

    D'Agostino, Giancarlo; Mana, Giovanni; Oddone, Massimo; Pramann, Axel; Prata, Michele

    2016-01-01

    The latest determination of the Avogadro constant, carried out by counting the atoms in a pure silicon crystal highly enriched in 28Si, reached the target 2x10-8 relative uncertainty required for the redefinition of the kilogram based on the Planck constant. The knowledge of the isotopic composition of the enriched silicon material is central; it is measured by isotope dilution mass spectrometry. In this work, an independent estimate of the 30Si mole fraction was obtained by applying a relative measurement protocol based on Instrumental Neutron Activation Analysis. The amount of 30Si isotope was determined by counting the 1266.1 keV gamma-photons emitted during the radioactive decay of the radioisotope 31Si produced via the neutron capture reaction 30Si(n,gamma)31Si. The x(30Si) = 1.043(19)x10-6 mol mol-1 is consistent with the value currently adopted by the International Avogadro Coordination.

  18. Study and development of new dosemeters for thermal neutrons; Estudio y desarrollo de nuevos dosimetros para neutrones termicos

    Energy Technology Data Exchange (ETDEWEB)

    Urena N, F

    1998-12-31

    An alanine-boron compound, alanine hydroborate, was synthesized and chemically characterized to be used for thermal neutrons fluence measurements. The synthesis of the compound was made by reacting the amino acid alanine with boric acid in three different media: acidic, neutral and alkaline. Physicochemical analysis showed that the alkaline medium is favorable for the synthesis of the alanine hydroborate. The compound was evaluated as a thermal neutron fluence detector by the detection of the free radical yield upon neutron thermal irradiation by Electron Paramagnetic Resonance (EPR). The present work also studies the EPR-signal response of the three preparations to thermal neutron irradiation ({phi} = 5 x 10{sup 7} n/cm{sup 2} -s). The following EPR signal parameters of the samples were investigated: peak-to-peak signal intensity vs. thermal neutron fluence {Phi} = {phi} {Delta}t ; where {Delta}t = 1, 5, 10, 20, 40, 60, 80, 90, 100, 110 and 120 h. , peak-to-peak signal intensity vs. microwave power, signal fading; repeatability, batch homogeneity, stability and zero dose response. It is concluded that these new products could be used in thermal neutron fluence estimations. (Author)

  19. Investigation of Kpong carbonatite as a potential source for rare earth elements (REEs) using instrumental neutron activation analysis (INAA)

    Energy Technology Data Exchange (ETDEWEB)

    Hayford, M.S.; Akiti, T.T.; Serfor-Armah, Y.; Dampare, S.B. [Ghana Univ., Accra (Ghana). School of Nuclear and Allied Sciences; Ghana Atomic Energy Commission (GAEC), Legon-Accra (Ghana). Nuclear Chemistry and Environmental Research Centre

    2013-07-01

    Instrumental neutron activation analysis (INAA) was used to investigate REEs in carbonatite from Kpong southeastern, Ghana. Total rare earth element (TREEs) obtain were in the range of 540 mg/kg to 705 mg/kg. The total number of rare earth elements (REEs) determined by INAA in the carbonatite rocks from Kpong were 11, namely; La, Ce, Nd, Sm, Eu, Tb, Dy, Ho, Tm, Yb, Lu. The INAA results from the carbonatite show a high enrichment of light rare earth elements (LREEs) deposits, marking the Kpong carbonatite as a potential REE source. (orig.)

  20. Determination of macro, micro nutrient and trace element concentrations in Indian medicinal and vegetable leaves using instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Naidu, G.R.K.; Balaji, T. [Department of Chemistry, S.V. University, Tirupati (India); Denschlag, H.O.; Mauerhofer, E.; Porte, N. [Institut fuer Kernchemie, Johannes Gutenberg Universitaet, Mainz (Germany)

    1999-05-01

    Leafy samples often used as medicine in the Indian Ayurvedic system and vegetables were analyzed for 20 elements (As, Ba, Br, Ca, Ce, Cr, Cs, Co, Eu, Fe, K, La, Na, Rb, Sb, Sc, Sm, Sr, Th, Zn) by employing Instrumental Neutron Activation Analysis (INAA). The samples were irradiated at the 100 kW TRIGA-MAINZ nuclear reactor and the induced activities were counted by gamma ray spectrometry using an efficiency calibrated high resolution High Purity Germanium (HPGe) detector. The concentration of the elements in the medicinal and vegetable leaves and their biological effects on human beings are discussed.

  1. Thermal neutron flux measurement using the DUPIC SPND-instrumented rig

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C. Y.; Moon, J. S.; Park, H. S.; Kang, K. H.; Ryu, H. J.; Jeong, I. H.; Song, K. C.; Yang, M. S. [KAERI, Taejon (Korea, Republic of)

    2002-05-01

    The 3rd irradiation test of DUPIC fuel, which was fabricated in the DFDF(DUPIC Fuel Development Facility) was performed in HANARO. For the objectives of this irradiation test, the newly designed irradiation rig was equipped with three Rh- type SPND sensors around DUPIC mini-elements for estimating the thermal neutron flux in the OR4 hole. The thermal neutron flux was measured at this location for 5 months the start of the test. The measured data were transmitted to monitoring system. We confirmed that the trend of SPND signal is well agree with that of HANARO power. The measured average thermal neutron flux is 0.45 n/cm{sup 2} {center_dot}s and the average linear power of DUPIC mini-element was estimated to be 33.5 KW/m.

  2. Final qualification of an industrial wide range neutron instrumentation in the Osiris MTR reactor

    Energy Technology Data Exchange (ETDEWEB)

    Barbot, L.; Normand, S. [CEA, LIST, Laboratoire Capteur et Architectures Electroniques, F-91191 Gif Sur Yvette (France); Pasdeloup, P. [AREVA TA, Controle Commande and Mesures, F-13762 Les Milles (France); Lescop, B. [CEA, INSTN, UEIN, F-91191 Gif Sur Yvette (France)

    2009-07-01

    This work deals with the final qualification of the IRINA in-core neutron flux measurement system in the MTR Osiris reactor. A specific irradiation device has been set up to validate the last changes in the complete system (electronic, transmitting cable and monitor). Experimental results show the IRINA measurement system meet entirely the in-core reactor conditions requirements: a thermal neutron flux from 10{sup 7} n.cm{sup -2}.s{sup -1} up to 10{sup 14} n.cm{sup -2}.s{sup -1} and a temperature of 300 C degrees during a minimum operating time of 1000 hours. (authors)

  3. Instrumentation

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Journal Scope:Instrumentation is a high quality open access peer reviewed research journal.Authors are solicited to contribute to these journals by submitting articles that illustrate most up-to-date research results,projects,surveying works and industrial experiences that describe significant advances in the instrumental science.The mission of the Instrumentation is

  4. A novel approach to neutron scattering instrumentation for probing multiscale dynamics in soft and biological matter

    Science.gov (United States)

    Mamontov, Eugene

    2016-09-01

    We present a concept and ray-tracing simulation of a mechanical device that will enable inelastic neutron scattering measurements where the data at energy transfers from a few μeV to several hundred meV can be collected in a single, gapless spectrum. Besides covering 5 orders of magnitude on the energy (time) scale, the device provides data over 2 orders of magnitude on the scattering momentum (length) scale in a single measurement. Such capabilities are geared primarily toward soft and biological matter, where the broad dynamical features of relaxation origin largely overlap with vibration features, thus necessitating gapless spectral coverage over several orders of magnitude in time and space. Furthermore, neutron scattering experiments with such a device are performed with a fixed neutron final energy, which enables measurements, with neutron energy loss in the sample, at arbitrarily low temperatures over the same broad spectral range. This capability is also invaluable in biological and soft matter research, as the variable temperature dependence of different relaxation components allows their separation in the scattering spectra as a function of temperature.

  5. Advanced sources and optical components for the McStas neutron scattering instrument simulation package

    DEFF Research Database (Denmark)

    Farhi, E.; Monzat, C.; Arnerin, R.

    2014-01-01

    as in Guide_anyshape component for reflecting or absorbing complex set-up. The PSD_Detector component models a neutron absorbing gas volume, taking into account for instance the penetration depth and the associated parallax effect, the charge cloud generated at the absorption location. This gas volume can...

  6. Measuring the noble metal and iodine composition of extracted noble metal phase from spent nuclear fuel using instrumental neutron activation analysis.

    Science.gov (United States)

    Palomares, R I; Dayman, K J; Landsberger, S; Biegalski, S R; Soderquist, C Z; Casella, A J; Brady Raap, M C; Schwantes, J M

    2015-04-01

    Masses of noble metal and iodine nuclides in the metallic noble metal phase extracted from spent fuel are measured using instrumental neutron activation analysis. Nuclide presence is predicted using fission yield analysis, and radionuclides are identified and the masses quantified using neutron activation analysis. The nuclide compositions of noble metal phase derived from two dissolution methods, UO2 fuel dissolved in nitric acid and UO2 fuel dissolved in ammonium-carbonate and hydrogen-peroxide solution, are compared.

  7. Non-Fick ian law for the neutron density current; Atomos para el desarrollo de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa P, G.; Vazquez R, R. [UAM-Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, Mexico D.F. 09340 (Mexico); Morales S, J. [UNAM, Laboratorio de Analisis en Ingenieria de Reactores Nucleares, Paseo Cuauhnahuac 8532, Jiutepec, Morelos 62550 (Mexico)]. e-mail: gepe@xanum.uam.mx

    2008-07-01

    In this paper, a fractional wave equation for the average neutron motion in a nuclear reactor is considered. This representation covers the full spectrum of the average neutron transport behavior, i.e., Fick ian and non-Fick ian effects. The fractional diffusion model retains the main dynamic characteristics of the neutron motion. The relaxation time associated with a rapid variation in the neutron flux contains an adjustable parameter, which can be manipulated to obtain the best representation of the neutron transport phenomena. (Author)

  8. Rapid determination of halogenes in milk by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Alfassi, Z.B.; Lavi, N.

    1985-07-01

    The absolute concetrations of iodine, bromine and chlorine in milk were determined by epithermal neutron activation followed by high resolution gamma-ray spectrometry. Two kinds of milk commonly consumed in Israel were investigated. The concentration of iodine, bromine and chlorine were found to be 0.18-0.30 ..mu..g/ml, 2.02-2.85 ..mu..g/ml and 0.65 mg/ml, respectively. The method is fast, selective, accurate and highly sensitive.

  9. Experimental verification of equilibrium para-hydrogen levels in hydrogen moderators irradiated by spallation neutrons at J-PARC

    Science.gov (United States)

    Teshigawara, M.; Harada, M.; Tatsumoto, H.; Aso, T.; Ohtsu, K.; Takada, H.; Futakawa, M.; Ikeda, Y.

    2016-02-01

    By sampling gaseous hydrogen from a circulating liquid hydrogen loop for Laser Raman spectroscopy, we measured the para-/ortho-hydrogen fractions in liquid hydrogen under neutron irradiation for the first time to identify whether irradiated hydrogen has an elevated ortho-hydrogen fraction. This measurement indicates that para-hydrogen equilibrium persists at 300 kW proton power in the presence of an iron(III) oxide hydroxide [Fe(OH)3] catalyst. The measurements will be repeated as the power at the Japan Proton Accelerator Research Complex (J-PARC) increases to the MW level.

  10. Instrumentation

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Journal Scope:Instrumentation is a high quality open access peer reviewed research journal.Authors are solicited to contribute to these journals by submitting articles that illustrate most up-to-date research results,projects,surveying works and industrial experiences that describe significant advances in the instrumental science.The mission of the Instrumentation is to provide a platform for the researchers,academicians,

  11. LabVIEW-based control software for para-hydrogen induced polarization instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Agraz, Jose, E-mail: joseagraz@ucla.edu; Grunfeld, Alexander; Li, Debiao [Department of Bioengineering, University of California, Los Angeles, California 91791 (United States); BIRI, Cedars Sinai Medical Center, West Hollywood, California 90048 (United States); Cunningham, Karl [Ectron Corp, San Diego, California 92111 (United States); Willey, Cindy [Harris Corp, San Diego, California 92154 (United States); Pozos, Robert [Department of Biology, San Diego State University, San Diego, California 92182 (United States); Wagner, Shawn [BIRI, Cedars Sinai Medical Center, West Hollywood, California 90048 (United States)

    2014-04-15

    The elucidation of cell metabolic mechanisms is the modern underpinning of the diagnosis, treatment, and in some cases the prevention of disease. Para-Hydrogen induced polarization (PHIP) enhances magnetic resonance imaging (MRI) signals over 10 000 fold, allowing for the MRI of cell metabolic mechanisms. This signal enhancement is the result of hyperpolarizing endogenous substances used as contrast agents during imaging. PHIP instrumentation hyperpolarizes Carbon-13 ({sup 13}C) based substances using a process requiring control of a number of factors: chemical reaction timing, gas flow, monitoring of a static magnetic field (B{sub o}), radio frequency (RF) irradiation timing, reaction temperature, and gas pressures. Current PHIP instruments manually control the hyperpolarization process resulting in the lack of the precise control of factors listed above, resulting in non-reproducible results. We discuss the design and implementation of a LabVIEW based computer program that automatically and precisely controls the delivery and manipulation of gases and samples, monitoring gas pressures, environmental temperature, and RF sample irradiation. We show that the automated control over the hyperpolarization process results in the hyperpolarization of hydroxyethylpropionate. The implementation of this software provides the fast prototyping of PHIP instrumentation for the evaluation of a myriad of {sup 13}C based endogenous contrast agents used in molecular imaging.

  12. LabVIEW-based control software for para-hydrogen induced polarization instrumentation.

    Science.gov (United States)

    Agraz, Jose; Grunfeld, Alexander; Li, Debiao; Cunningham, Karl; Willey, Cindy; Pozos, Robert; Wagner, Shawn

    2014-04-01

    The elucidation of cell metabolic mechanisms is the modern underpinning of the diagnosis, treatment, and in some cases the prevention of disease. Para-Hydrogen induced polarization (PHIP) enhances magnetic resonance imaging (MRI) signals over 10,000 fold, allowing for the MRI of cell metabolic mechanisms. This signal enhancement is the result of hyperpolarizing endogenous substances used as contrast agents during imaging. PHIP instrumentation hyperpolarizes Carbon-13 ((13)C) based substances using a process requiring control of a number of factors: chemical reaction timing, gas flow, monitoring of a static magnetic field (Bo), radio frequency (RF) irradiation timing, reaction temperature, and gas pressures. Current PHIP instruments manually control the hyperpolarization process resulting in the lack of the precise control of factors listed above, resulting in non-reproducible results. We discuss the design and implementation of a LabVIEW based computer program that automatically and precisely controls the delivery and manipulation of gases and samples, monitoring gas pressures, environmental temperature, and RF sample irradiation. We show that the automated control over the hyperpolarization process results in the hyperpolarization of hydroxyethylpropionate. The implementation of this software provides the fast prototyping of PHIP instrumentation for the evaluation of a myriad of (13)C based endogenous contrast agents used in molecular imaging.

  13. Determination of Pu content in a Spent Fuel Assembly by Measuring Passive Total Neutron count rate and Multiplication with the Differential Die-Away Instrument

    Energy Technology Data Exchange (ETDEWEB)

    Henzl, Vladimir [Los Alamos National Laboratory; Croft, Stephen [Los Alamos National Laboratory; Swinhoe, Martyn T. [Los Alamos National Laboratory; Tobin, Stephen J. [Los Alamos National Laboratory

    2012-07-13

    Inspired by approach of Bignan and Martin-Didier (ESARDA 1991) we introduce novel (instrument independent) approach based on multiplication and passive neutron. Based on simulations of SFL-1 the accuracy of determination of {sup tot}Pu content with new approach is {approx}1.3-1.5%. Method applicable for DDA instrument, since it can measure both multiplication and passive neutron count rate. Comparison of pro's & con's of measuring/determining of {sup 239}Pu{sub eff} and {sup tot}Pu suggests a potential for enhanced diversion detection sensitivity.

  14. Monte Carlo simulations as a part of the configuration for neutron instruments

    DEFF Research Database (Denmark)

    Andersen, P.; Lefmann, K.; Kuhn, L.T.

    2004-01-01

    with powder diffraction. The agreement in resolution and signal-to-background ratio between measurements and simulations shows the validity of the approach. For a sample with broadened Bragg peaks, the optimal instrument configuration could be established only on careful consideration. This shows...... that in general instrument simulations are approaching a state where they can assist users in selectingthe optimal configuration and possibly demonstrate the feasibility of their experiments prior to allocated beamtime. (C) 2004 Elsevier B.V. All rights reserved....

  15. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2001-04-01

    SCK-CEN's research and development programme on instrumentation involves the assessment and the development of sensitive measurement systems used within a radiation environment. Particular emphasis is on the assessment of optical fibre components and their adaptability to radiation environments. The evaluation of ageing processes of instrumentation in fission plants, the development of specific data evaluation strategies to compensate for ageing induced degradation of sensors and cable performance form part of these activities. In 2000, particular emphasis was on in-core reactor instrumentation applied to fusion, accelerator driven and water-cooled fission reactors. This involved the development of high performance instrumentation for irradiation experiments in the BR2 reactor in support of new instrumentation needs for MYRRHA, and for diagnostic systems for the ITER reactor.

  16. Evolutionary neural networks: a new alternative for neutron spectrometry; Redes neuronales evolutivas: una nueva alternativa para la espectrometria de neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz R, J. M. [Departamento de Electrotecnia y Electronica, Escuela Politecnica Superior, Av. Menendez Pidal s/n, 14004 Cordoba (Spain); Martinez B, M. R.; Vega C, H. R. [Unidad Academica de Estudios Nucleares, Universidad Autonoma de Zacatecas, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Galleo, E. [Departamento de Ingenieria Nuclear, Universidad Politecnica de Madrid, Jose Gutierrez Abascal 2, 28006 Madrid (Spain)], e-mail: morvymm@yahoo.com.mx

    2009-10-15

    A device used to perform neutron spectroscopy is the system known as a system of Bonner spheres spectrometer, this system has some disadvantages, one of these is the need for reconstruction using a code that is based on an iterative reconstruction algorithm, whose greater inconvenience is the need for a initial spectrum, as close as possible to the spectrum that is desired to avoid this inconvenience has been reported several procedures in reconstruction, combined with various types of experimental methods, based on artificial intelligence technology how genetic algorithms, artificial neural networks and hybrid systems evolved artificial neural networks using genetic algorithms. This paper analyzes the intersection of neural networks and evolutionary algorithms applied in the neutron spectroscopy and dosimetry. Due to this is an emerging technology, there are not tools for doing analysis of the obtained results, by what this paper presents a computing tool to analyze the neutron spectra and the equivalent doses obtained through the hybrid technology of neural networks and genetic algorithms. The toolmaker offers a user graphical environment, friendly and easy to operate. (author)

  17. Characterization of film-converter screens systems for neutron radiography; Caracterizacao de sistemas filme-conversor para radiografia com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Marcos Leandro Garcia

    2002-07-01

    In general a good quality radiography is that one able to furnish high contrast and sharp edge images. Technically 'high contrast' means high capability to discern material thickness and 'sharp edges', high resolution power. In the present work the optimal conditions to obtain neutron radiography images by using the following film-converter screen systems, Kodak-AA/Gd vaporated; Kodak-AA/Gd metallic; Kodak-AA/LiF; Min-R/GdS{sub 2}O{sub 4}, have been determined. The irradiations were performed in a radiographic facility which was designed and constructed by the neutron radiography working group and is installed at the beamhole 08 of the IEA-R1 nuclear research reactor of the IPEN-CNEN/SP. In order to determine such conditions, the start point was to evaluate the neutron exposure interval for which the optical contrast is maximal and so quantify the sensitivity or capability to discern material thickness, as well as the spatial resolution achieved in the radiographic image, for these systems. The best results have been obtained for the Kodak-AA/Gd vaporated system which is able to discern, for example, 0,024 cm of lucite, with a maximal resolution of 22{mu}m. The radiography images presently obtained in IPEN-CNEN/SP have similar quality when compared to the ones from several other research centers, around the world, whose making use of the same film-converter screens systems. (author)

  18. Simulation of a suite of generic long-pulse neutron instruments to optimize the time structure of the European Spallation Source

    DEFF Research Database (Denmark)

    Lefmann, Kim; Klenø, Kaspar H.; Birk, Jonas Okkels;

    2013-01-01

    between 10 Hz and 25 Hz. The relative change in performance with time structure is given for each instrument, and an unweighted average is calculated. The performance of the instrument suite is proportional to (a) the peak flux and (b) the duty cycle to a power of approximately 0.3. This information......We here describe the result of simulations of 15 generic neutron instruments for the long-pulsed European Spallation Source. All instruments have been simulated for 20 different settings of the source time structure, corresponding to pulse lengths between 1 ms and 2 ms; and repetition frequencies...

  19. The response of the Sievert instrument in neutron beams up to 180 MeV

    CERN Document Server

    Kylionen, J E; Samuelson, G

    2001-01-01

    Measurements with a tissue-equivalent proportional counter (TEPC) using the variance-covariance method have been performed in neutron beams between 71 keV and 180 MeV and in the cosmic radiation reference field (CERF) at CERN. The results show that with appropriate linear Q/sub D/(y/sub D/) relations, the ambient dose equivalent can be determined within about 55% in these beams. Build- up measurements show that wall thickness is not crucial for H* determinations at 60 and 180 MeV. (26 refs).

  20. Determination of silver, gold, zinc and copper in mineral samples by various techniques of instrumental neutron activation analysis; Determinacion de plata, oro, zinc y cobre en muestras minerales mediante diversas tecnicas de analisis por activacion de neutrones instrumental

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez R, N. I.; Rios M, C.; Pinedo V, J. L. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico); Yoho, M.; Landsberger, S., E-mail: neisla126@hotmail.com [University of Texas at Austin, Nuclear Engineering Teaching Laboratory, Austin 78712, Texas (United States)

    2015-09-15

    Using the method of instrumental neutron activation analysis, mineral exploration samples were analyzed in order to determine the concentrations of silver, gold, zinc and copper; these minerals being the main products of benefit of Tizapa and Cozamin mines. Samples were subjected to various techniques, where the type of radiation and counting methods were chosen based on the specific isotopic characteristics of each element. For calibration and determination of concentrations the comparator method was used, certified standards were subjected to the same conditions of irradiation and measurement that the prospecting samples. The irradiations were performed at the research reactor TRIGA Mark II of the University of Texas at Austin. The silver concentrations were determined by Cyclical Epithermal Neutron Activation Analysis. This method in combination with the transfer pneumatic system allowed a good analytical precision and accuracy in prospecting for silver, from photo peak measurement 657.7 keV of short half-life radionuclide {sup 110}Ag. For the determination of gold and zinc, Epithermal Neutron Activation Analysis was used, the photo peaks analyzed corresponded to the energies 411.8 keV of radionuclide {sup 199}Au and 438.6 keV of metastable radionuclide {sup 69m}Zn. On the other hand, copper quantification was based on the photo peak analysis of 1039.2 keV produced by the short half-life radionuclide {sup 66}Cu, by Thermal Neutron Activation Analysis. The photo peaks measurement corresponding to gold, zinc and copper was performed using a Compton suppression system, which allowed an improvement in the signal to noise relationship, so that better detection limits and low uncertainties associated with the results were obtained. Comparing elemental concentrations the highest values in silver, zinc and copper was for samples of mine Tizapa. Regarding gold values were found in the same range for both mines. To evaluate the precision and accuracy of the methods used

  1. Comparison of neutron dose quantities and instrument and dosemeter readings at representative locations in an MOX fuel fabrication plant

    CERN Document Server

    Bartlett, D T; Tanner, R J; Haley, R M; Cooper, A J

    2002-01-01

    The relationships between operational and protection quantities, and values of personal dosemeter and instrument readings have been determined for a recently designed MOX fuel fabrication plant. The relationships between the quantities, and the readings of personal dosemeters are sensitive to both the energy and direction distribution of neutron fluence. The energy distributions were calculated using the Monte Carlo code MCBEND. The direction distribution was addressed by calculating independently, spectral components for which the direction distribution could be reasonably assumed. At representative locations, and for assumed worker orientations, the radiation field is analysed as having, in general, three components--a direct, unidirectional component from the nearest identified discrete source, which is considered incident A-P, several unidirectional components from other such sources which are treated as a rotational component and a scattered isotropic component. The calculated spectra were folded with co...

  2. Evaluation of trace elements in chewing tobacco and snuff using instrumental neutron activation analysis (INAA) and atomic absorption spectroscopy (AAS)

    Energy Technology Data Exchange (ETDEWEB)

    Waheed, S.; Siddique, N.; Rahman, S. [Chemistry Div., Directorate of Science, Pakistan Inst. of Nuclear Science and Tech., Islamabad (Pakistan)

    2009-07-01

    Nine samples of chewing tobacco, snuff, tobacco leaf and ash were analyzed using Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectroscopy (AAS). Almost all samples of chewing tobacco and snuff studied in this work contain substantial amounts of Mg, Mn, Na, K. V. Sc, Rb and Fe. Furthermore, varying amounts of Al, Ba, Ca, Ce, Co and Zn were also detected in all tobacco samples. Of the toxic elements which were determined using INAA. As, Sb and Hg were quantified in only few tobacco samples. However, other toxic elements, which were determined using AAS, such as Cu, Pb and Cd were detected in almost all samples of chewing tobacco and snuff. The concentration of majority of the detected elements is high in ash samples which imply that most elements in chewing tobacco and snuff may originate from the addition of ash. (orig.)

  3. Simultaneous multi-element determination in different seed samples of Dodonaea viscosa hopseed using instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    El-Sweify, Fatma H.; El-Amir, Mahmoud A.; Mostafa, Mohamed; Ramadan, Hala E.; Rashad, Ghada M. [Atomic Energy Authority, Cairo (Egypt). Hot Lab. Center

    2016-07-01

    Instrumental neutron activation analysis technique (INAA) was applied for nondestructive multi-element analysis of seed samples of the plant Dodonaea viscosa hopseed. This plant is distributed all over Egypt, because of its suitable properties. The samples were collected from some bushes grown at different sites in some governorates, in July of each year during the period from 2004 to 2011. The determined elements are: Co, Cs, Eu, Fe, Hg, Ni, Rb, Sc, Se, Sr and Zn, under the chosen irradiation and cooling times. The content of some elements has been compared with data obtained from previous work on analysis of various kinds of seeds. The influence of some parameters on the determined elemental content is discussed. Standard reference materials IAEA-155 and IAEA-V-10 were used to assure quality control, accuracy and precision of the technique.

  4. Delayed neutron fraction and prompt decay constant measurement in the MINERVE reactor using the PSI instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Perret, Gregory [Paul Scherrer Institute, Villigen, 5232, (Switzerland)

    2015-07-01

    The critical decay constant (B/A), delayed neutron fraction (B) and generation time (A) of the Minerve reactor were measured by the Paul Scherrer Institut (PSI) and the Commissariat a l'Energie Atomique (CEA) in September 2014 using the Feynman-alpha and Power Spectral Density neutron noise measurement techniques. Three slightly subcritical configuration were measured using two 1-g {sup 235}U fission chambers. This paper reports on the results obtained by PSI in the near critical configuration (-2g). The most reliable and precise results were obtained with the Cross-Power Spectral Density technique: B = 708.4±9.2 pcm, B/A = 79.0±0.6 s{sup -1} and A 89.7±1.4 micros. Predictions of the same kinetic parameters were obtained with MCNP5-v1.6 and the JEFF-3.1 and ENDF/B-VII.1 nuclear data libraries. On average the predictions for B and B/A overestimate the experimental results by 5% and 11%, respectively. The discrepancy is suspected to come from either a corruption of the data or from the inadequacy of the point kinetic equations to interpret the measurements in the Minerve driven system. (authors)

  5. Development of a microtpc detector as a standard instrument for low energy neutron field characterization

    CERN Document Server

    Maire, D; Bosson, G; Bourrion, O; Guillaudin, O; Lamblin, J; Lebreton, L; Mayet, F; Médard, J; Muraz, J-F; Richer, J-P; Riffard, Q; Santos, D

    2013-01-01

    In order to measure energy and fluence of neutron fields, with energy ranging from 8 keV to 1 MeV, a new primary standard is being developed at the IRSN (Institute for Radioprotection and Nuclear Safety). This project, micro-TPC (Micro Time Projection Chamber), carried out in collaboration with the LPSC, is based on the nucleus recoil detector principle. The measurement strategy requires track reconstruction of recoiling nuclei down to a few keV, which can be achieved with a low pressure gaseous detector using a micro-pattern gaseous detector. A gas mixture, mainly isobutane, is used as a n-p converter to detect neutrons into the detection volume. Then electrons, coming from the ionization of the gas by the proton recoil, are collected by the pixelised anode (2D projection). A self-triggered electronics is able to perform the anode readout at a 50 MHz frequency in order to give the third dimension of the track. Then the scattering angle is deduced from this track using algorithms. The charge collection leads ...

  6. Study of Neutron From a Dense Plasma Focus Paco Instrument by Means of Nuclear Tracks Detectors

    Directory of Open Access Journals (Sweden)

    M. Milanese

    2016-08-01

    Full Text Available A most interesting feature of dense plasma foci is the acceleration of charge particle at energy in the range of MeV per nucleon. Using deuterium gas, this devices produce fusion D-D reactions, generation fast neutron pulses (~ 2.5 MeV. The device used in the present work is a Mather-type dense plasma focus, called PACO. It is a 2kJ device at 31 kV, with an oxygen-free copper anode, 50 mm long with 40 mm diameter. The coaxial cathode is formed by ten copper rods arranged in a squirrel cage configuration at a radius of 50mm. The insulator in an annular Pyrex® tube located at the base of the anode. The energy store is provided by four 1 µF (40 kV, 40 nH capacitors in parallel. The plasma focus was operated at 1.5 mb deuterium gas pressure. Neutron and accelerated particles are analyzed with material detectors (CR-39 Lantrack® for different conditions. A detailed study is made of track diameters when the plastic is chemically etched with, 6N KOH at 60°C (±1 for 12 h.

  7. Monte Carlo simulations as a part of the configuration for neutron instruments

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, P.; Lefmann, K.; Theil Kuhn, L.; Willendrup, P.K.; Farhi, E

    2004-07-15

    We demonstrate the use of simulations in the process of determining the optimal instrument setup by virtual experiments using the simulation package McStas. The focus of the analysis is the optimization of the multi-blade analyzer present at the RITA-II spectrometer at PSI for a test experiment with powder diffraction. The agreement in resolution and signal-to-background ratio between measurements and simulations shows the validity of the approach. For a sample with broadened Bragg peaks, the optimal instrument configuration could be established only on careful consideration. This shows that in general instrument simulations are approaching a state where they can assist users in selecting the optimal configuration and possibly demonstrate the feasibility of their experiments prior to allocated beamtime.

  8. Monte Carlo simulations as a part of the configuration for neutron instruments

    Science.gov (United States)

    Andersen, P.; Lefmann, K.; Theil Kuhn, L.; Willendrup, P. K.; Farhi, E.

    2004-07-01

    We demonstrate the use of simulations in the process of determining the optimal instrument setup by virtual experiments using the simulation package McStas. The focus of the analysis is the optimization of the multi-blade analyzer present at the RITA-II spectrometer at PSI for a test experiment with powder diffraction. The agreement in resolution and signal-to-background ratio between measurements and simulations shows the validity of the approach. For a sample with broadened Bragg peaks, the optimal instrument configuration could be established only on careful consideration. This shows that in general instrument simulations are approaching a state where they can assist users in selecting the optimal configuration and possibly demonstrate the feasibility of their experiments prior to allocated beamtime.

  9. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2002-04-01

    SCK-CEN's R and D programme on instrumentation involves the development of advanced instrumentation systems for nuclear applications as well as the assessment of the performance of these instruments in a radiation environment. Particular emphasis is on the use of optical fibres as umbilincal links of a remote handling unit for use during maintanance of a fusion reacor, studies on the radiation hardening of plasma diagnostic systems; investigations on new instrumentation for the future MYRRHA accelerator driven system; space applications related to radiation-hardened lenses; the development of new approaches for dose, temperature and strain measurements; the assessment of radiation-hardened sensors and motors for remote handling tasks and studies of dose measurement systems including the use of optical fibres. Progress and achievements in these areas for 2001 are described.

  10. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2000-07-01

    SCK-CEN's research and development programme on instrumentation aims at evaluating the potentials of new instrumentation technologies under the severe constraints of a nuclear application. It focuses on the tolerance of sensors to high radiation doses, including optical fibre sensors, and on the related intelligent data processing needed to cope with the nuclear constraints. Main achievements in these domains in 1999 are summarised.

  11. Using Instrumental Neutron Activation Analysis for geochemical analyses of terrestrial impact structures: Current analytical procedures at the University of Vienna Geochemistry Activation Analysis Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Mader, Dieter [Department of Lithospheric Research, University of Vienna, Althanstrasse 14, 1090 Vienna (Austria)], E-mail: dieter.mader@univie.ac.at; Koeberl, Christian [Department of Lithospheric Research, University of Vienna, Althanstrasse 14, 1090 Vienna (Austria)], E-mail: christian.koeberl@univie.ac.at

    2009-12-15

    The Instrumental Neutron Activation Analysis Gamma Spectroscopy Laboratory at the Department of Lithospheric Research, University of Vienna, has been upgraded in the year 2006. This paper describes the sample preparation, new instrumentation and data evaluation for hundreds of rock samples of two terrestrial impact structures. The measurement and data evaluation are done by using Genie{sup TM} 2000 and a custom-made batch software for the used analysis sequences.

  12. Determination of several elements in sediment samples from Nizao River basin, Dominican Republic by instrumental neutron activation analysis; Determinacao de diversos elementos em amostras de sedimento da bacia do Rio Nizao da Republica Dominicana por ativacao neutronica instrumental

    Energy Technology Data Exchange (ETDEWEB)

    Kastner, Geraldo Frederico; Vilhena Schayer Sabino, Claudia de [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)

    1995-12-31

    The Neutron Activation Laboratory at CDTN (Nuclear Technology Development Institute, Brazilian) (CNEN) has been acquiring through the years experience to determine several elements answering to analytical requests, including regional, national and international projects. Through neutron activation instrumental, gamma spectrometry and fission delayed neutron technique were analysed 50 samples of sediment from basin of Nizao River, Dominican Republic: Al, Fe, Mn, Na, Cr, Co, La, Sc, U and V with the objective to determine the concentration in both different parts: argil and sand. It was necessary to improve the irradiation conditions, delay time, counting, geometry and others proceedings due parameters like neutron flux, half life time of the radionuclide, gamma energies, all interfering in the procedures. The irradiations were carried about at IPR R1 TRIGA MARK I reactor. (author). 5 refs., 3 figs., 5 tabs.

  13. Procedure to measure the neutrons spectrum around a lineal accelerator for radiotherapy; Procedimiento para medir el espectro de los neutrones en torno a un acelerador lineal para radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H. R.; Hernandez D, V. M.; Letechipia de L, C. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas (Mexico); Benites R, J. L. [Servicios de Salud de Nayarit, Centro Estatal de Cancerologia, Calzada de la Cruz 116 Sur, 63000 Tepic, Nayarit (Mexico); Salas L, M. A., E-mail: fermineutron@yahoo.com [Universidad Autonoma de Zacatecas, Unidad Academica de Agronomia, Apdo. Postal 336, 98000 Zacatecas (Mexico)

    2013-10-15

    An experimental procedure was developed, by means of Bonner spheres, to measure the neutrons spectrum around Linacs of medical use that only requires of a single shot of the accelerator; to this procedure we denominate Planetary or Isocentric method. One of the problems associated to the neutrons spectrum measurement in a radiotherapy room with lineal accelerator is because inside the room a mixed, intense and pulsed radiation field takes place affecting the detection systems based on active detector; this situation is solved using a passive detector. In the case of the Bonner spheres spectrometer the active detector has been substituted by activation detectors, trace detectors or thermoluminescent dosimeters. This spectrometer uses several spheres that are situated one at a time in the measurement point, this way to have the complete measurements group the accelerator should be operated, under the same conditions, so many times like spheres have the spectrometer, this activity can consume a long time and in occasions due to the work load of Linac to complicate the measurement process too. The procedure developed in this work consisted on to situate all the spectrometer spheres at the same time and to make the reading by means of a single shot, to be able to apply this procedure, is necessary that before the measurements two characteristics are evaluated: the cross-talking of the spheres and the symmetry conditions of the neutron field. This method has been applied to determine the photo-neutrons spectrum produced by a lineal accelerator of medical use Varian ix of 15 MV to 100 cm of the isocenter located to 5 cm of depth of a solid water mannequin of 30 x 30 x 15 cm. The spectrum was used to determine the total flow and the environmental dose equivalent. (Author)

  14. Precision velocimetry planet hunting with PARAS: current performance and lessons to inform future extreme precision radial velocity instruments

    Science.gov (United States)

    Roy, Arpita; Chakraborty, Abhijit; Mahadevan, Suvrath; Chaturvedi, Priyanka; Prasad, Neelam J. S. S. V.; Shah, Vishal; Pathan, F. M.; Anandarao, B. G.

    2016-08-01

    The PRL Advanced Radial-velocity Abu-sky Search (PARAS) instrument is a fiber-fed stabilized high-resolution cross-dispersed echelle spectrograph, located on the 1.2 m telescope in Mt. Abu India. Designed for exoplanet detection, PARAS is capable of single-shot spectral coverage of 3800 - 9600 Å, and currently achieving radial velocity (RV) precisions approaching 1 m s-1 over several months using simultaneous ThAr calibration. As such, it is one of the few dedicated stabilized fiber-fed spectrographs on small (1-2 m) telescopes that are able to fill an important niche in RV follow-up and stellar characterization. The success of ground-based RV surveys is motivating the push into extreme precisions, with goals of 10 cm s-1 in the optical and <1 m s-1 in the near-infrared (NIR). Lessons from existing instruments like PARAS are invaluable in informing hardware design, providing pipeline prototypes, and guiding scientific surveys. Here we present our current precision estimates of PARAS based on observations of bright RV standard stars, and describe the evolution of the data reduction and RV analysis pipeline as instrument characterization progresses and we gather longer baselines of data. Secondly, we discuss how our experience with PARAS is a critical component in the development of future cutting edge instruments like (1) the Habitable Zone Planet Finder (HPF), a near-infrared spectrograph optimized to look for planets around M dwarfs, scheduled to be commissioned on the Hobby Eberly Telescope in 2017, and (2) the NEID optical spectrograph, designed in response to the NN-EXPLORE call for an extreme precision Doppler spectrometer (EPDS) for the WIYN telescope. In anticipation of instruments like TESS and GAIA, the ground-based RV support system is being reinforced. We emphasize that instruments like PARAS will play an intrinsic role in providing both complementary follow-up and battlefront experience for these next generation of precision velocimeters.

  15. Area monitor for neutrons with thin sheet of Au; Monitor de area para neutrones con laminilla de Au

    Energy Technology Data Exchange (ETDEWEB)

    Valero L, C.; Guzman G, K. A.; Banuelos F, A.; Borja H, C. G.; Hernandez D, V. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Gallego, E.; Lorente, A., E-mail: fermineutron@yahoo.com [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, C/ Jose Gutierrez Abascal 2, E-28006 Madrid (Spain)

    2011-11-15

    A passive area monitor for neutrons with an activation detector was designed and constructed to be used in sites where the radiation field is mixed, intense and pulsed, like happens in the radiotherapy rooms that use lineal accelerators of medical use or in enclosures with cyclotrons for PET, or where the field is mixed and intense as in the nuclear power plants. This equipment is useful for the exposition cases of the patients or workers that receive not counted radiation dose, generating harmful effects to the health, for what is necessary to take the pertinent measures for the radiological protection. The design of the area monitor was realized using the MCNP5 code, where was considered an activation detector and therefore thin sheets of Au-197 located in the moderator center were used. The moderator was designed as a polyethylene cylindrical to moderate the neutrons. The gold was used like detector for its high cross section and its physical and chemical characteristics. The response of the monitor is maxim for energies from 1 to 20 MeV, region where the flowing coefficients and dose are majors. Therefore, the designed and constructed monitor can be used in sites with high, mixed and pulsed radiation fields. (Author)

  16. Differential Die-Away Instrument: Report on Neutron Detector Recovery Performance and Proposed Improvements

    Energy Technology Data Exchange (ETDEWEB)

    Goodsell, Alison Victoria [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Swinhoe, Martyn Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Henzl, Vladimir [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ianakiev, Kiril Dimitrov [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Iliev, Metodi [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rael, Carlos D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Desimone, David J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-09-22

    Four helium-3 (3He) detector/preamplifier packages (¾”/KM200, DDSI/PDT-A111, DDA/PDT-A111, and DDA/PDT10A) were experimentally tested to determine the deadtime effects at different DT neutron generator output settings. At very high count rates, the ¾”/KM200 package performed best. At high count rates, the ¾”/KM200 and the DDSI/PDT-A111 packages performed very well, with the DDSI/PDT-A111 operating with slightly higher efficiency. All of the packages performed similarly at mid to low count rates. Proposed improvements include using a fast recovery LANL-made dual channel preamplifier, testing smaller diameter 3He tubes, and further investigating quench gases.

  17. Analysis of umayyad islamic silver coins (Dirhams) by using instrumental neutron activation analysis

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Islamic silver coins (Dirhams) running the period between 107 to 126 Hijri (726-743AD), which belong to the Umayyad Empire period, 41-132 hijri (661-750AD), were selected for analysis by using instrumentalneutron activation analysis techniques.During this period (105-126H),(724-743AD), the Caliph Hisham Eben Abdlemalek ruled the Umayyad Empire.Dirhams were irradiated in a reactor neutron activation facility.Levels of various elements viz.Cu, Ag and Au were estimated.It was found that the average silver concentration, the baseconstituent of the Dirham, was about 88wt%.Correlation between thecomposition of Dirhams and the historical implications was discussed.

  18. Instrumental neutron activation analysis of an enriched 28Si single-crystal

    CERN Document Server

    DAgostino, G; Giordani, L; Mana, G; Oddone, M

    2013-01-01

    The determination of the Avogadro constant plays a key role in the redefinition of the kilogram in terms of a fundamental constant. The present experiment makes use of a silicon single-crystal highly enriched in 28Si that must have a total impurity mass fraction smaller than a few parts in 109. To verify this requirement, we previously developed a relative analytical method based on neutron activation for the elemental characterization of a sample of the precursor natural silicon crystal WASO 04. The method is now extended to fifty-nine elements and applied to a monoisotopic 28Si single-crystal that was grown to test the achievable enrichment. Since this crystal was likely contaminated, this measurement tested also the detection capabilities of the analysis. The results quantified contaminations by Ge, Ga, As, Tm, Lu, Ta, W and Ir and, for a number of the detectable elements, demonstrated that we can already reach the targeted 1 ng/g detection limit.

  19. Multi-elemental profile of some Brazilian make-up products by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Dalmazio, Ilza; Menezes, Maria Angela de B.C., E-mail: id@cdtn.b, E-mail: menezes@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Reator e Tecnicas Analiticas. Lab. de Ativacao Neutronica

    2011-07-01

    Recent works have shown that analysis in cosmetics and beauty products from the European and Asian markets indicate the presence of U, Th and rare earths besides other trace elements. Considering these previous findings and health issues, it would be valuable to obtain information on elements in cosmetics available in the Brazilian market. The purpose of this study was to acquire a multi-elemental profile of some Brazilian make-up products of diverse brands. Samples of eye shadow, liquid base, facial concealer, lipstick, and compact face powder were analyzed applying neutron activation analysis, k{sub 0}-standardization method at CDTN/CNEN, using the TRIGA Mark I IPR-R1 research reactor. Concentrations of more than 30 elements in samples are presented and it was found elements included in Brazilian National Health Surveillance Agency prohibitive list, rare earths, Th and U in a minimum of two cosmetic samples. (author)

  20. Multi-elemental profile of some Brazilian make-up products by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Dalmazio, Ilza; Menezes, Maria Angela de B.C., E-mail: id@cdtn.b, E-mail: menezes@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Reator e Tecnicas Analiticas. Lab. de Ativacao Neutronica

    2011-07-01

    Recent works have shown that analysis in cosmetics and beauty products from the European and Asian markets indicate the presence of U, Th and rare earths besides other trace elements. Considering these previous findings and health issues, it would be valuable to obtain information on elements in cosmetics available in the Brazilian market. The purpose of this study was to acquire a multi-elemental profile of some Brazilian make-up products of diverse brands. Samples of eye shadow, liquid base, facial concealer, lipstick, and compact face powder were analyzed applying neutron activation analysis, k{sub 0}-standardization method at CDTN/CNEN, using the TRIGA Mark I IPR-R1 research reactor. Concentrations of more than 30 elements in samples are presented and it was found elements included in Brazilian National Health Surveillance Agency prohibitive list, rare earths, Th and U in a minimum of two cosmetic samples. (author)

  1. iFit: a new data analysis framework. Applications for data reduction and optimization of neutron scattering instrument simulations with McStas

    DEFF Research Database (Denmark)

    Farhi, E.; Y., Debab,; Willendrup, Peter Kjær

    2014-01-01

    and noisy problems. These optimizers can then be used to fit models onto data objects, and optimize McStas instrument simulations. As an application, we propose a methodology to analyse neutron scattering measurements in a pure Monte Carlo optimization procedure using McStas and iFit. As opposed...

  2. Differences between cross-section libraries for neutron dosimetry; Diferencas entre bibliotecas de secoes de choque para dosimetria de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Tardelli, T.C.; Stecher, L.C.; Coelho, T.S.; Castro, V.A. De; Cavalieri, T.A.; Menzel, F.; Giarola, R.S.; Domingos, D.B.; Yoriyaz, H., E-mail: tiago.tardelli@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Engenharia Nuclear

    2013-08-15

    Absorbed dose calculations depend on a consistent set of nuclear data used in simulations in computer codes. Nuclear data are stored in libraries, however, the information available about the differences in dose caused by different libraries are rare. The libraries are processed by a computer system to be able to be used by a radiation transport code. One of the systems capable of processing nuclear data is the NJOY system. The objective of this study is to evaluate the nuclear data libraries for neutrons available in the literature, and to quantify the differences in absorbed dose obtained using the libraries JENDL 4.0, JEFF 3.3.1 and ENDF/B.VII. The absorbed dose calculation was performed on a simple geometric model, as spheres, and in anthropomorphic model of the human body based on the ICRP-110 for neutron transport simulation using the MCNP5 code. The results were compared with literature data. The results obtained with cross sections from the libraries JEFF and ENDF/B.VII have shown to be identical in most cases, except for one case where the difference has exceeded 10%. The results obtained with JENDL library has shown to be considerably different in most cases comparing to other two libraries. Some differences were over 200%. The dose calculations showed differences between the libraries, which is justified by differences in the cross sections. It has been observed that the cross sections values of certain nuclides assume quite different values in different libraries. These differences in turn cause considerable differences in dose calculations. (author)

  3. Instruments

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

    The present paper mediates a basic knowledge of the most commonly used experimental techniques. We discuss the principles and concepts necessary to understand what one is doing if one performs an experiment on a certain instrument. (author) 29 figs., 1 tab., refs.

  4. Instrumentation

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Journal Scope:Instrumentation is a high quality open access peer reviewed research journal,Authors are solicited to contribute to these journals by submitting articles that illustrate most up-to-date research results,projects,surveying works and industrial

  5. Comparative measurement of inorganic elements in Korean space foods using instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong Sam; Kim, Sun Ha; Baek, Sung Ryel; Sun, Gwang Min; Moon, Jong Hwa; Choi, Jong Il; Lee, Joo Eun [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    In April 2008, Korea's first astronaut became a crew member of the international space station and she brought special space versions of traditional Korean dishes such as kimchi, boiled rice, hot red pepper paste, soybean paste soup, ginseng tea, green tea, and ramyun. To date, seventy kinds of Korean space foods (KSFs) have been developed by KAERI. The information and role of trace mineral elements from an intake of created and processed foodstuff are important as a indicator of human health and nutrition, as well as a quality control of food and diet. In particular, special food created for consumption by astronauts in outer space may differ with common food on the earth to compensate a decrease in taste and nutrition by hygienic sterilization processing as well as strong cosmic rays, a state of non gravitation, low pressure, and an enclosed space environment. An accurate quantitative analysis of trace elements in various kinds of biological samples is serious work for analytical data quality. An neutron activation analysis is a sensitive, non destructive, multi elemental analytical method without loss and contamination of a sample by chemical pre treatment. The aim of this study is to identify and to compare the distribution of concentrations for essential and functional inorganic elements in six kinds of Korean space foods developed by KAERI in 2011 using INAA.

  6. Californium interrogation prompt neutron (CIPN) instrument for non-destructive assay of spent nuclear fuel-Design concept and experimental demonstration

    Science.gov (United States)

    Henzlova, D.; Menlove, H. O.; Rael, C. D.; Trellue, H. R.; Tobin, S. J.; Park, Se-Hwan; Oh, Jong-Myeong; Lee, Seung-Kyu; Ahn, Seong-Kyu; Kwon, In-Chan; Kim, Ho-Dong

    2016-01-01

    This paper presents results of the first experimental demonstration of the Californium Interrogation Prompt Neutron (CIPN) instrument developed within a multi-year effort launched by the Next Generation Safeguards Initiative Spent Fuel Project of the United States Department of Energy. The goals of this project focused on developing viable non-destructive assay techniques with capabilities to improve an independent verification of spent fuel assembly characteristics. For this purpose, the CIPN instrument combines active and passive neutron interrogation, along with passive gamma-ray measurements, to provide three independent observables. This paper describes the initial feasibility demonstration of the CIPN instrument, which involved measurements of four pressurized-water-reactor spent fuel assemblies with different levels of burnup and two initial enrichments. The measurements were performed at the Post-Irradiation Examination Facility at the Korea Atomic Energy Institute in the Republic of Korea. The key aim of the demonstration was to evaluate CIPN instrument performance under realistic deployment conditions, with the focus on a detailed assessment of systematic uncertainties that are best evaluated experimentally. The measurements revealed good positioning reproducibility, as well as a high degree of insensitivity of the CIPN instrument's response to irregularities in a radial burnup profile. Systematic uncertainty of individual CIPN instrument signals due to assembly rotation was found to be independent of assembly orientation in the instrument.

  7. Rapid and accurate determination of barium by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Armelin, Maria Jose A.; Maihara, Vera A.; Saiki, Mitiko, E-mail: marmelin@ipen.br, E-mail: vmaihara@ipen.br, E-mail: mitiko@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Trevizam, Anderson R., E-mail: aanrt@hotmail.com [Universidade Estadual do Centro Oeste (UNICENTRO), Guarapuava, PR (Brazil)

    2013-07-01

    Barium is an alkaline earth metal naturally present in soils. When available at a high level in the soil it can cause toxicity to plants and animals. Not all the barium is readily available to living organisms. Inorganic and organic barium compounds can be presented as soluble or insoluble forms in the soil. The soluble form of BaS is extremely toxic to humans, animals and plants. Researchers have noted a decrease of K absorption in the plant when Ba concentrations are increased and a change in overall plant growth. In case of animals, Ba tends to be concentrated in the bones which may compete with calcium, although only about 2% barium ingested in dietary is absorbed by the body. Another effect is that the Ba can interfere with the availability of sulfur in the soil due to the sulphate formation of low solubility. Barium and some other elements are considered palioclimatic proxies. For some researchers, barite is perhaps the most appropriate indicator of paleoproductivity because of a high resistance to dissolution. As explained about the barium effects in various situations, it was considered important to study the more appropriated experimental conditions for determination of this element by INAA. Conditions established for this analysis were: a) Irradiation time, 15 and 40 seconds, under thermal flux neutron about 4 x 10{sup 12} n cm{sup -2} s{sup -1}, for determining barium in geological and biological matrices, respectively; b) Decay time, approximately of 4 minutes; c) Counting time of 30 minutes; d) Radionuclide measured {sup 139}Ba. The quality of Ba results was evaluated from the analysis of certified reference materials. The performance of the method was satisfactory, according to the criterion of E.ζ score. Results obtained in this study indicate INAA is a good alternative for Ba determination in geological and biological samples. (author)

  8. Study of some Ayurvedic Indian medicinal plants for the essential trace elemental contents by instrumental neutron activation analysis and atomic absorption spectroscopy techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lokhande, R.S.; Singare, P.U.; Andhele, M.L. [Dept. of Chemistry, Univ. of Mumbai, Santacruz, Mumbai (India); Acharya, R.; Nair, A.G.C.; Reddy, A.V.R. [Radiochemistry Div., Bhabha Atomic Research Centre, Trombay, Mumbai (India)

    2009-07-01

    Elemental analysis of some medicinal plants used in the Indian Ayurvedic system was performed by employing instrumental neutron activation analysis (INAA) and atomic absorption spectroscopy (AAS) techniques. The samples were irradiated with thermal neutrons in a nuclear reactor and the induced activity was counted by gamma ray spectrometry using an efficiency calibrated high resolution high purity germanium (HPGe) detector. Most of the medicinal plants were found to be rich in one or more of the elements under study. The variation in elemental concentration in same medicinal plants samples collected in summer, winter and rainy seasons was studied and the biological effects of these elements on human beings are discussed. (orig.)

  9. The structure of para-toluidine by X-ray and neutron diffraction; Etude de la structure de la para-toluidine par la diffraction des rayons X et des neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Bertinotti, A.L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-12-01

    The crystal and molecular structure of para-toluidine has been solved by X-ray and neutron diffraction counter techniques. The molecules are arranged in the form of infinite chains in the crystal, each molecule being linked to two neighbours by hydrogen bonds. The presence of the H bonds makes clear the difference in the melting points between para-toluidine and benzene hydrocarbons of related symmetry and molecular weight. Their direction accounts for the (001) cleavage and the growth anisotropy of crystals from supersaturated vapour phase. A structure-seeking method by computer has been elaborated, using lattice energy calculations applied to molecules treated as rigid bodies and making use of a simplex method for function minimization without calculation of derivatives. The way the available information is handled allows to increase the range of convergence, as shown in the case of para-toluidine. (author) [French] La structure cristalline et moleculaire de la para-toluidine a ete resolue a l'aide de la diffraction des rayons X et des neutrons. L'analyse a revele que la structure presentait un encha ement particulier des molecules, liees entre elles par des ponts hydrogene. La presence des liaisons rend compte de l'elevation du point de fusion de la para-toluidine par rapport a celui des carbures benzeniques de symetrie et de poids moleculaires voisins. La direction des liaisons explique le clivage facile (001) des cristaux obtenus par fusion et l'anisotropie de croissance des cristaux en phase vapeur. Une methode de recherche de structures par ordinateur a ete elaboree, faisant usage du concept d'energie reticulaire applique aux molecules considerees comme rigides et faisant appel a une methode de simplexe pour la minimisation des fonctions sans calcul de derivees. La maniere dont est exploitee l'information disponible permet d'accro re, comme cela est montre dans le cas de la para-toluidine, l'etendue du domaine de

  10. Determination of airborne cadmium in environmental tobacco smoke by instrumental neutron activation analysis with a compton suppression system.

    Science.gov (United States)

    Landsberger, S; Larson, S; Wu, D

    1993-06-01

    Concentrations of cadmium, a toxic trace element, were measured in the indoor air of several public places where environmental tobacco smoke was present. Particulate-phase cadmium concentrations were determined by analyzing air filter samples using epithermal instrumental neutron activation analysis in conjunction with a Compton suppression gamma-ray detection system, in which the detection limit for cadmium was reduced to a few nanograms per filter. A cascade impactor and a personal filter sampler were used to collect the indoor suspended particulate matter for size-fractionated mass as well as total mass, respectively. Results show that where environmental tobacco smoke is present, cadmium concentrations are significantly higher than background and that about 80% of the cadmium found in indoor airborne particulate matter is associated with particles with aerodynamic diameters less than 1.8 microns. In one instance, airborne cadmium concentrations in a music club were found to be 38 ng/m, which is at least 30 times higher than background.

  11. Elemental content of mosses and lichens from Livingston Island (Antarctica) as determined by instrumental neutron activation analysis (INAA).

    Science.gov (United States)

    Culicov, Otilia A; Yurukova, Liliana; Duliu, Octavian G; Zinicovscaia, Inga

    2017-02-01

    The total content of 8 major and 32 trace elements in four species of mosses and two of lichens as well as neighboring soil and rocks collected from different places of the Livingston Island Antarctica was determined by instrumental neutron activation analysis. The main goals of the project consisted of evidencing the possible trace of anthropogenic contamination as well as the influence of altitude on the distribution of considered elements. In the absence of a unanimously accepted descriptor, enrichment factor, geo-accumulation, and pollution load indices with respect to soil and rocks were used. The data, interpreted within the model of a reference plant, were compared with previous studies regarding the same organisms in similar geographic and climatological areas. The experimental results evidenced different capacity of mosses and lichens to retain the considered elements, but within experimental uncertainties, no traces of anthropogenic pollution were found. At the same time, it was found that the content of most of the elements decreased with the altitude.

  12. A preliminary study of archaeological ceramic from the Sao Paulo II, Brazil, archaeological site by Instrumental Neutron Activation Analysis (INAA)

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Rogerio B.; Munita, Casimiro S.; Oliveira, Paulo M.S., E-mail: camunita@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Neves, Eduardo G.; Tamahara, Eduardo K., E-mail: edgneves@usp.br [Museu de Arqueologia e Etnologia (MAE/USP), Sao Paulo, SP (Brazil)

    2011-07-01

    The determination of trace elements plays an important role in the characterization of archaeological ceramics. It is well established that ceramics can be grouped based on similarities/dissimilarities derived from chemical data. Different analytical methods can be applied to determine the sample composition. Instrumental neutron activation analysis (INAA) is the method preferred because present several advantages in relation to the other techniques. In this work, the elements determined were As, K, La, Lu, Na, Nd, Sb, Sm, U, Yb, Ba, Ce, Co, Cr, Cs, I, Fe, Hf, Rb, Sc, Ta , Tb, Th and Zn to carry out a preliminary chemical characterization in 44 ceramic samples from Sao Paulo II archaeological site by INAA. The site is located in Coari city, 363 km from Manaus, Amazonas state (AM). The elementary concentration results were studied using multivariate statistical methods. The similarity/dissimilarity among the samples was studied by means of discriminant analysis. The compositions group classification was done through cluster analysis, showing the formation of the three distinct groups of the ceramics. (author)

  13. Investigations of Ancient Terra-cotta Sarcophagi, Excavated in Enez (Ainos Turkey, by Instrumental Neutron Activation Analysis

    Directory of Open Access Journals (Sweden)

    Sevim Akyuz

    2015-12-01

    Full Text Available Ten terra-cotta sarcophagi, together with a terra-cotta aryballos (perfume jar, excavated in Su Terazisi necropolis of Enez-Turkey (Ancient Ainos, were investigated by Instrumental Neutron Activation Analysis (INAA, to determine the concentration of thirty two chemical elements: Na, K, Ca, Fe, Sc, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Dy, Yb, Lu, Hf, Ta, Th and U. The dataset was submitted to multivariate statistical analysis. The classification was done by cluster analysis. The results demonstrated the occurrence of two different groups of terra-cotta samples. Group I contains nine sarcophagi and terra-cotta aryballos whereas group II contains only one sample (E09-ST5-M26. High correlations between La and Ce (r2 = 0.92, and U and Th (r2 = 0.91 indicated that local clay was used for manufacturing the terra-cotta sarcophagi and aryballos but probably the claybed used for E09-ST5-M26 was different from that of others.

  14. Response to ``Comment on `Elastic incoherent neutron scattering operating by varying instrumental energy resolution: Principle, simulations, and experiments of the resolution elastic neutron scattering (RENS)''' [Rev. Sci. Instrum. 83, 107101 (2012)

    Science.gov (United States)

    Magazó, Salvatore; Migliardo, Federica; Benedetto, Antonio

    2012-10-01

    Recently [S. Magazù et al., Rev. Sci. Instrum. 82, 105115 (2011), 10.1063/1.3641870] we have proposed a new method for characterizing, by neutron scattering, the dynamical properties of complex material systems, such as, the ones of interest in the biophysical field. This approach called Resolution Elastic Neutron Scattering, in short RENS, is based on the detection of the elastically scattered neutron intensity as a function of the instrumental energy resolution. By experimental, theoretical, and numerical findings, we have pointed out that an inflection point occurs in the elastic intensity when the system relaxation time approaches the instrumental energy resolution time. This approach, differently from quasi-elastic neutron scattering (QENS), gives the chance to evaluate the system relaxation times without using pre-defined models that can be wrong and/or misleading. Here, we reply to a Comment on the above-mentioned main paper in which Wuttke proposes a different approach to evaluate the above-mentioned inflection point; on this regard, it should be noticed that the existence of the inflection point, which is the main topic of our work, is not questioned and that the approach proposed by Wuttke in the Comment, although valid for a class of dynamical processes, is not applicable when different and distinct processes occur simultaneously at different time scale.

  15. Response to 'Comment on 'Elastic incoherent neutron scattering operating by varying instrumental energy resolution: Principle, simulations, and experiments of the resolution elastic neutron scattering (RENS)'' [Rev. Sci. Instrum. 83, 107101 (2012)

    Energy Technology Data Exchange (ETDEWEB)

    Magazu, Salvatore; Migliardo, Federica; Benedetto, Antonio [Dipartimento di Fisica, Universita di Messina, C.da Papardo n Degree-Sign 31, P.O. Box 55, Vill. S. Agata 98166 Messina (Italy)

    2012-10-15

    Recently [S. Magazu et al., Rev. Sci. Instrum. 82, 105115 (2011)] we have proposed a new method for characterizing, by neutron scattering, the dynamical properties of complex material systems, such as, the ones of interest in the biophysical field. This approach called Resolution Elastic Neutron Scattering, in short RENS, is based on the detection of the elastically scattered neutron intensity as a function of the instrumental energy resolution. By experimental, theoretical, and numerical findings, we have pointed out that an inflection point occurs in the elastic intensity when the system relaxation time approaches the instrumental energy resolution time. This approach, differently from quasi-elastic neutron scattering (QENS), gives the chance to evaluate the system relaxation times without using pre-defined models that can be wrong and/or misleading. Here, we reply to a Comment on the above-mentioned main paper in which Wuttke proposes a different approach to evaluate the above-mentioned inflection point; on this regard, it should be noticed that the existence of the inflection point, which is the main topic of our work, is not questioned and that the approach proposed by Wuttke in the Comment, although valid for a class of dynamical processes, is not applicable when different and distinct processes occur simultaneously at different time scale.

  16. Evaluation of area monitor response for neutrons in radiation field generated by a 15 MV clinic accelerator; Avaliacao da resposta dos monitores de area para neutrons em campo de radiacao gerado por um acelerador clinico de 15 MV

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, Ana Paula

    2011-07-01

    The clinical importance and usage of linear accelerators in cancer treatment increased significantly in the last years. Coupled with this growth came the concern about the use of accelerators with energies over to 10 MeV which produce therapeutic beam contaminated with neutrons generated when high-energy photons interact with high-atomic-number materials such as tungsten and lead present in the accelerator itself. At these facilities, measurements of the ambient dose equivalent for neutrons present difficulties owing to the existence of a mixed radiation field and possible electromagnetic interference near the accelerator. The Neutron Laboratory of the IRD - Brazilian Institute for Radioprotection and Dosimetry, aiming to evaluate the survey meters performance at these facilities, initiated studies of instrumentation response in the presence of different neutron spectra. Neutrons sources with average energies ranging from 0.55 to 4.2 MeV, four different survey meters and one ionization chamber to obtain the ratio between the dose due to neutrons and gamma radiation were used in this work. The evaluation of these measurements, performed in a 15 MV linear accelerator room is presented. This work presents results that demonstrate the complexity and care needed to make neutrons measurements in radiotherapy treatment rooms containing high energy clinical accelerators. (author)

  17. DESARROLLO DE UN INSTRUMENTO VIRTUAL PARA EL BALANCEAMIENTO DINAMICO DE ROTORES DEVELOPMENT OF A VIRTUAL INSTRUMENT FOR ROTOR DYNAMICS BALANCING

    Directory of Open Access Journals (Sweden)

    Edgar Estupiñán P

    2006-08-01

    Full Text Available El presente trabajo resalta la importancia del balanceamiento de rotores como principal herramienta dentro de las tareas correctivas del mantenimiento predictivo, con el fin de que se reduzcan las vibraciones y sus efectos secundarios en las máquinas rotatorias. Se ha desarrollado un instrumento virtual para el balanceamiento dinámico de rotores, basado en un sistema de adquisición de datos (SAD. El instrumento tiene incluidos todos los cálculos necesarios para balancear rotores en un plano y en dos planos, a partir de la medición de los datos de vibración, utilizando el procedimiento de los coeficientes de influencia o utilizando un procedimiento de medición sin fase. También se ha incluido un módulo para determinar la severidad vibratoria del rotor y un módulo de análisis de vibraciones, que incluye análisis espectral y de la forma de onda. Este instrumento virtual es una herramienta útil para el balanceamiento de rotores en laboratorio así como también en la industria.This article highlights the importance of rotor balancing like the most important corrective action included in a predictive maintenance program, whose main objective is reducing the vibrations level and its secondary effect in rotary machines. A virtual instrument, based in a data acquisition system has been developed for rotor balancing. With this instrument it is possible to balance rotors in a single or two-plane, using the influence coefficient method or a no phase method. Also the instrument includes a function to determine the vibration severity and a function of vibration analysis with spectral and waveform analysis included. This virtual instrument is useful for rotor balancing in the laboratory as well as in the industry.

  18. Elemental characterization of trifala powders and tablets by instrumental neutron activation analysis, thermal analysis and spectral studies of gallic acid.

    Science.gov (United States)

    Choudhury, R Paul; Kumar, A; Garg, A N

    2007-01-01

    Trifala is one of the most popular herbal formulations, marketed either as powder or a tablet and is used in all parts of India. It is an effective laxative, antioxidant, anticancer and antidiabetic agent, and is used to refresh the eyes. In order to understand the therapeutic uses of trifala, the powder and tablet forms from Zandu Pharmaceuticals, Mumbai, were analyzed for six minor (Na, K, Mg, Ca, Cl and P) and 23 trace (Al, Ba, Br, Cd, Co, Cr, Cs, Cu, Fe, Eu, Hf, Hg, La, Mn, Ni, P, Pb, Rb, Sb, Se, Th, V and Zn) elements. The elements were determined by employing instrumental neutron activation analysis (INAA) and atomic absorption spectrophotometry (AAS). A comparison of the elemental contents in the powder and tablets showed wide variations. The powder was rich in Cr, Fe, Se and Zn, whereas the tablet contained a four-fold higher Mn compared to the powder. Column and thin layer chromatography (TLC) in ethyl acetate/methanol (7:3) were used for the separation of gallic acid in ethanolic extract. It was further confirmed by elemental analysis and spectral methods and quantitatively estimated to the extent of approximately 2%. Thermogravimetric decomposition studies show a three stage process, first a slow process with approximately 20% wt loss at temperatures up to 200 degrees C followed by a fast process losing another 30-35% wt at approximately 300 degrees C for both the powder and tablets. At 700 degrees C metal oxide residue of 7.5 and approximately 16% were left for powder and tablets, respectively.

  19. Inventario para la medición del engagement (ilusión por el trabajo. Un estudio instrumental

    Directory of Open Access Journals (Sweden)

    Teresita De Jesus Cardenas Aguilar

    2014-07-01

    Full Text Available El presente artículo de investigación da a conocer los resultados de una investigación que tuvo como objetivo identificar el nivel de confiabilidad y validez del “Inventario para la Medición del Engagement en el Trabajo” (IMET. Los objetivos se alcanzaron a través de un estudio instrumental en el que se aplicó dicho inventario a 572 docentes de la ciudad de Durango, México. Los resultados obtenidos con la aplicación de este instrumento, permitieron demostrar una alta confiabilidad y validez para medir el engagement. Abstract This article shows the results of a study that identified the level of reliability and validity of the “Inventory for Measuring Engagement at Work” (IMET. The objectives were achieved through an instrumental study. The instrument was administered to 572 teachers in the city of Durango, Mexico. The results obtained with the application of this instrument, allowed to demonstrate high reliability and validity for measuring engagement.

  20. Linear extended neutron diffusion theory for semi-in finites homogeneous means; Teoria de difusion de neutrones lineal extendida para medios homogeneos semi-infinitos

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez R, R.; Vazquez R, A.; Espinosa P, G. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Area de Ingenieria en Recursos Energeticos, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)], e-mail: rvr@xanum.uam.mx

    2009-10-15

    Originally developed for heterogeneous means, the linear extended neutron diffusion theory is applied to the limit case of monoenergetic neutron diffusion in a semi-infinite homogeneous mean with a neutron source, located in the coordinate origin situated in the frontier of dispersive material. The monoenergetic neutron diffusion is studied taking into account the spatial deviations in the neutron flux to the interfacial current caused by the neutron source, as well as the influence of the spatial deviations in the absorption rate. The developed pattern is an unidimensional model for an energy group obtained of application of volumetric average diffusion equation in the moderator. The obtained results are compared against the classic diffusion theory and qualitatively against the neutron transport theory. (Author)

  1. 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...

  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. Desarrollo de un controlador para motores DC brushless basado en CompactRIO y LabVIEW de National Instruments para el estudio de nuevos algoritmos de control

    OpenAIRE

    García Haro, Juan Miguel

    2011-01-01

    Este proyecto que el CAR inició hace pocos años tiene como objetivo principal el estudio y desarrollo de nuevas tecnologías en el campo de actuación y control automático, que servirá de base para otras futuras investigaciones dentro del centro. La tecnología a la que se hace mención se refiere al control de actuadores basados en motores DC brushless (BLDC Motors) empleando el sistema de hardware embebido CompactRIO y programación LabVIEW de National Instruments. Tradicionalmente se emplea en ...

  4. Proceedings of the Oak Ridge National Laboratory/Brookhaven National Laboratory workshop on neutron scattering instrumentation at high-flux reactors

    Energy Technology Data Exchange (ETDEWEB)

    McBee, M.R. (ed.); Axe, J.D.; Hayter, J.B.

    1990-07-01

    For the first three decades following World War II, the US, which pioneered the field of neutron scattering research, enjoyed uncontested leadership in the field. By the mid-1970's, other countries, most notably through the West European consortium at Institut Laue-Langevin (ILL) in Grenoble, France, had begun funding neutron scattering on a scale unmatched in this country. By the early 1980's, observers charged with defining US scientific priorities began to stress the need for upgrading and expansion of US research reactor facilities. The conceptual design of the ANS facility is now well under way, and line-item funding for more advanced design is being sought for FY 1992. This should lead to a construction request in FY 1994 and start-up in FY 1999, assuming an optimal funding profile. While it may be too early to finalize designs for instruments whose construction is nearly a decade removed, it is imperative that we begin to develop the necessary concepts to ensure state-of-the-art instrumentation for the ANS. It is in this context that this Instrumentation Workshop was planned. The workshop touched upon many ideas that must be considered for the ANS, and as anticipated, several of the discussions and findings were relevant to the planning of the HFBR Upgrade. In addition, this report recognizes numerous opportunities for further breakthroughs on neutron instrumentation in areas such as improved detection schemes (including better tailored scintillation materials and image plates, and increased speed in both detection and data handling), in-beam monitors, transmission white beam polarizers, multilayers and supermirrors, and more. Each individual report has been cataloged separately.

  5. Small-angle neutron scattering instrument of Institute for Solid State Physics, the Univeristy of Tokyo (SANS-U) and its application to biology

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Yuji; Imai, Masayuki; Takahashi, Shiro [Univ. of Tokyo, Tokai Naka Ibaraki (Japan)

    1994-12-31

    A small-angle neutron spectrometer (SANS-U) suitable for the study of mesoscopic structure in the field of polymer chemistry and biology, has been constructed at the guide hall of JRR-3M reactor at the Japan Atomic Energy Research Institute. The instrument is 32m long and utilizes a mechanical velocity selector and pinhole collimation to provide a continuous beam with variable wavelength in the range from 5 to 10{Angstrom}. The neutron detector is a 65 x 65cm{sup 2} 2D position sensitive proportional counter. The practical Q range of SANS-U is 0.0008 to 0.45{Angstrom}{sup -1}. The design, characteristics and performance of SANS-U are described with some biological studies using SANS-U.

  6. Electronic instrumentation for the nuclear radiation measurement; Instrumentacion electronica para la medicion de la radiacion nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez J, F.J

    2005-07-01

    This work presents the obtained results in the research, development and construction of the electronic instrumentation required for the measurement of the essential characteristics of the nuclear radiation: The quantity of radiation and its energy components. With this information, many practical instruments can be developed and applied in different fields of science and technology. In this work, some instruments were developed for their application in the areas of medicine, industry, and particle physics research. Several measurement systems based on PIN type diodes are proposed for: a) the measurement of the operational characteristics of the X-ray machines and the X-rays emitted in medical radio-diagnostic, b) X-ray spectroscopy and c) radiation spectroscopy of charged particles. The contribution of this work is, precisely, the development of new instruments that use the PIN diode as the sensorial element. In this way, existing problems in nuclear instrumentation are overcame, specially in the fields of medical physics and particle physics. Likewise, different types of charge and current preamplifiers, with a high signal-to-noise ratio, were developed for these instruments. (Author)

  7. Precision velocimetry planet hunting with PARAS: Current performance and lessons to inform future extreme precision radial velocity instruments

    CERN Document Server

    Roy, Arpita; Mahadevan, Suvrath; Chaturvedi, Priyanka; Prasad, Neelam J S S V; Shah, Vishal; Pathan, F M; Anandarao, B G

    2016-01-01

    PARAS is a fiber-fed stabilized high-resolution cross-dispersed echelle spectrograph, located on the 1.2 m telescope in Mt. Abu India. Designed for exoplanet detection, PARAS is capable of single-shot spectral coverage of 3800 - 9600 A, and currently achieving radial velocity (RV) precisions approaching ~1 m/s over several months using simultaneous ThAr calibration. As such, it is one of the few dedicated stabilized fiber-fed spectrographs on small (1-2 m) telescopes that are able to fill an important niche in RV follow-up and stellar characterization. The success of ground-based RV surveys is motivating the push into extreme precisions, with goals of ~10 cm/s in the optical and <1 m/s in the near-infrared (NIR). Lessons from existing instruments like PARAS are invaluable in informing hardware design, providing pipeline prototypes, and guiding scientific surveys. Here we present our current precision estimates of PARAS based on observations of bright RV standard stars, and describe the evolution of the dat...

  8. Calculation of neutron fluence to dose equivalent conversion coefficients using GEANT4; Calculo de coeficientes de fluencia de neutrons para equivalente de dose individual utilizando o GEANT4

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Rosane M.; Santos, Denison de S.; Queiroz Filho, Pedro P. de; Mauricio, CLaudia L.P.; Silva, Livia K. da; Pessanha, Paula R., E-mail: rosanemribeiro@oi.com.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    Fluence to dose equivalent conversion coefficients provide the basis for the calculation of area and personal monitors. Recently, the ICRP has started a revision of these coefficients, including new Monte Carlo codes for benchmarking. So far, little information is available about neutron transport below 10 MeV in tissue-equivalent (TE) material performed with Monte Carlo GEANT4 code. The objective of this work is to calculate neutron fluence to personal dose equivalent conversion coefficients, H{sub p} (10)/Φ, with GEANT4 code. The incidence of monoenergetic neutrons was simulated as an expanded and aligned field, with energies ranging between thermal neutrons to 10 MeV on the ICRU slab of dimension 30 x 30 x 15 cm{sup 3}, composed of 76.2% of oxygen, 10.1% of hydrogen, 11.1% of carbon and 2.6% of nitrogen. For all incident energy, a cylindrical sensitive volume is placed at a depth of 10 mm, in the largest surface of the slab (30 x 30 cm{sup 2}). Physic process are included for neutrons, photons and charged particles, and calculations are made for neutrons and secondary particles which reach the sensitive volume. Results obtained are thus compared with values published in ICRP 74. Neutron fluence in the sensitive volume was calculated for benchmarking. The Monte Carlo GEANT4 code was found to be appropriate to calculate neutron doses at energies below 10 MeV correctly. (author)

  9. Classificação Internacional para a Prática de Enfermagem: instrumental tecnológico para a prática profissional Clasificación Internacional para la Práctica de Enfermería: intrumentral tecnológico para la práctica profesional International Classification for Nursing Practice: technological instrument for professional practice

    Directory of Open Access Journals (Sweden)

    Maria Miriam Lima da Nóbrega

    2009-10-01

    Full Text Available Considera-se o uso de tecnologias de informação como instrumentos que podem fazer com que a prática de enfermagem se torne visível no conjunto de dados de saúde, locais, nacionais e internacionais, de modo a influenciar na elaboração de políticas de saúde e de educação. Aborda-se o desenvolvimento dos sistemas de classificação em enfermagem, com ênfase na Classificação Internacional para a Prática de Enfermagem - CIPE®, como instrumental tecnológico para a prática profissional, que tem como um dos principais critérios para sua construção o de ser suficientemente ampla e sensível à diversidade cultural, de modo que sirva aos múltiplos propósitos requeridos pelos distintos países onde será utilizada.El uso de tecnologías de información es considerado como instrumentos que pueden hacer la práctica de enfermería visible en los datos de salud, local, nacional e internacionalmente, de manera a influir en la elaboración de políticas de salud y educación. Aborda-se el desarrollo de los sistemas de la clasificación en enfermería se aproxima, con énfasis en la Clasificación Internacional para la Práctica de Enfermería - CIPE®, cono instrumental tecnológico para la practica profesional, que tiene como uno de los criterios para su construcción el de ser suficientemente ancho y sensible a la diversidad cultural, para que sirva a los múltiplos propósitos requeridos por los diferentes países dónde se la usará.The use of information technologies are considered as instruments that can do that nursing practice becomes visible in health data, local, national and internationally, in way to influence the elaboration of health and education policies. The development of nursing classification systems is approached, with emphasis in the International Classification for Nursing Practice - ICNP®, with technological instrument for professional practice, which has as one of the principal criteria for its construction to be

  10. Platinum determination by instrumental neutron activation analysis with special reference to the spectral interference of Sc-47 on the platinum indicator nuclide Au-199

    DEFF Research Database (Denmark)

    Alfassi, Z.B.; Probst, T.U.; Rietz, B.

    1998-01-01

    A method of instrumental neutron activation analysis (INAA) is developed for the determination of platinum by the Au-199 daughter of Pt-199 in the presence of the spectral interference from the Sc-47 daughter of Ca-47. The contributions of the Pt and Ca signals to the integral 157-161 keV peak were...... separated by calculating the number of disintegrations due to the Sc-47 from the signal of her parent Ca-47 at 1297.1 keV gamma-ray. The method was used to calculate the trace concentrations of Pt in air samples, collected on filters, (C) 1998 Elsevier Science B.V....

  11. Instrument electronic transformers for medium voltage systems; Transformadores eletronicos de instrumentos para sistemas de media tensao

    Energy Technology Data Exchange (ETDEWEB)

    Javora, Radek; Stefanka, Martin; Mahonen, Pentti; Niemi, Tapio; Rintamaki, Olli [ABB, Helsinki (Finland); ABB, Prague (Czech Republic)

    2010-02-15

    This paper compares the conventional technologies and the electronic of instrument transformers, and highlights the advantages, discoveries and principles of electronic models. Such equipment are essentially indicated for using with as micro processed relays at the substations, and also projected for connection to the IEDs, and the future digital communication (author)

  12. Amino acids analysis using grouping and parceling of neutrons cross sections techniques; Analise de aminoacidos atraves das tecnicas do agrupamento e parcelamento de secoes de choque para neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Voi, Dante Luiz Voi [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil); Rocha, Helio Fenandes da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Puericultura e Pediatria Martagao Gesteira

    2002-07-01

    Amino acids used in parenteral administration in hospital patients with special importance in nutritional applications were analyzed to compare with the manufactory data. Individual amino acid samples of phenylalanine, cysteine, methionine, tyrosine and threonine were measured with the neutron crystal spectrometer installed at the J-9 irradiation channel of the 1 kW Argonaut Reactor of the Instituto de Engenharia Nuclear (IEN). Gold and D{sub 2}O high purity samples were used for the experimental system calibration. Neutron cross section values were calculated from chemical composition, conformation and molecular structure analysis of the materials. Literature data were manipulated by parceling and grouping neutron cross sections. (author)

  13. La colorimetría instrumental: un auxiliar importante para la industria textil.

    OpenAIRE

    1994-01-01

    En este escrito, el autor realiza una revisión a vuelo pluma, de las bases y las posibilidades que ofrece en la actualidad,la medición instrumental del color en el sector textil, cuyas aplicaciones en la duplicación al color se hallan ampliamente difundidas, pero que también es de elevada utilidad en el control de calidad, no sólo del propio color, sino también en la valoración de las solkíeces, y delgrado de blanco. The author revises superficially the bases and present possibilities of i...

  14. An optional focusing SELENE extension to conventional neutron guides: A case study for the ESS instrument BIFROST

    Science.gov (United States)

    Hansen, U. B.; Bertelsen, M.; Stahn, J.; Lefmann, K.

    2017-04-01

    The high brilliance at the European Spallation Source (ESS) will allow for performing experiments with much smaller samples than at present neutron facilities and in much more complex sample environments. However the higher flux also results in higher background from unwanted neutrons not originating from scattering of the sample. We here present a new design idea for beam delivery, where a 165 m ballistic guide system with good transport properties is followed by a 4-8 m SELENE guide system similar to Montel optics used for X-ray optics. We have investigated the system by detailed Monte-Carlo simulations using McStas. We show that under certain conditions, this set-up works surprisingly well, with a brilliance transfer of 20-60% for neutrons of wavelength 4 Å and above. We demonstrate that the guide system is able to focus the beam almost perfectly onto samples sizes in the range of 0.1-2 mm. We furthermore show that our SELENE system is insensitive to gravity and to realistic values of guide waviness. We argue that this guide system can be useful as an optional guide insert when small samples are used in the vicinity of bulky sample environment, e.g. for high-field or high-pressure experiments.

  15. Avaliação da acuracia do instrumental utilizado para o levantamento de dados de casos de neoplasias malignas em hospitais de Campinas : subsidios para a organização de um registro de cancer de base populacional

    OpenAIRE

    Anna Valeria Gervasio de Britto

    1992-01-01

    Resumo: Para subsidiar a estruturação de um Registro de Câncer de Base Populacional em Campinas ( RCBP ), foi definida uma estratégia, e elaborado e testado um instrumental para a coleta de dados sobre neoplasias malignas, constituido por: ficha de cadastro de caso e manual com orientações para o seu preenchimento (anexo 2) e orientações sobre o trabalho e as neoplasias (anexo 3). Foram treinadas duas atendentes de enfermagem para coleta dos dados (coletadoras) e uma pessoa (codificador...

  16. Neutron fluence in a 18 MeV Electron Accelerator for Therapy; Fluencia de neutrones en un Acelerador de Electrones de 18 MeV para terapia

    Energy Technology Data Exchange (ETDEWEB)

    Paredes G, L.C. [Instituto Nacional de Investigaciones Nucleares, Direccion de Innovacion Tecnologica, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2001-07-01

    An investigation was made on the theoretical fundamentals for the determination of the neutron fluence in a linear electron accelerator for radiotherapy applications and the limit values of leakage neutron radiation established by guidelines and standards in radiation protection for these type of accelerators. This investigation includes the following parts: a) Exhaustive bibliographical review on the topics mentioned above, in order to combine and to update the necessary basic information to facilitate the understanding of this subject; b) Analysis of the accelerator operation and identification of its main components, specially in the accelerator head; c) Study of different types of targets and its materials for the Bremsstrahlung production which is based on the electron initial energy, the thickness of the target, and its angular distribution and energy, which influences in the neutron generation by means of the photonuclear and electro disintegration reactions; d) Analysis of the neutron yield based on the target type and its thickness, the energy of electrons and photons; e) Analysis of the neutron energy spectra generated in the accelerator head, inside and outside the treatment room; f) Study of the dosimetry fundamentals for neutron and photon mixed fields, the dosimeter selection criteria and standards applied for these applications, specially the Panasonic U D-809 thermoluminescent dosemeter and C R-39 nuclear track dosimeter; g) Theoretical calculation of the neutron yield using a simplified geometric model for the accelerator head with spherical cell, which considers the target, primary collimator, flattener filter, movable collimators and the head shielding as the main components for radiation production. The cases with W and Pb shielding for closed movable collimators and an irradiation field of 20 x 20 cm{sup 2} were analyzed and, h) Experimental evaluation of the leakage neutron radiation from the patient and head planes, observing that the

  17. Test and validation of the iterative code for the neutrons spectrometry and dosimetry: NSDUAZ; Prueba y validacion del codigo iterativo para la espectrometria y dosimetria de neutrones: NSDUAZ

    Energy Technology Data Exchange (ETDEWEB)

    Reyes H, A.; Ortiz R, J. M.; Reyes A, A.; Castaneda M, R.; Solis S, L. O.; Vega C, H. R., E-mail: alfredo_reyesh@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Ingenieria Electrica, Av. Lopez Velarde 801, Col. Centro, 98000 Zacatecas (Mexico)

    2014-08-15

    In this work was realized the test and validation of an iterative code for neutronic spectrometry known as Neutron Spectrometry and Dosimetry of the Universidad Autonoma de Zacatecas (NSDUAZ). This code was designed in a user graph interface, friendly and intuitive in the environment programming of LabVIEW using the iterative algorithm known as SPUNIT. The main characteristics of the program are: the automatic selection of the initial spectrum starting from the neutrons spectra catalog compiled by the International Atomic Energy Agency, the possibility to generate a report in HTML format that shows in graph and numeric way the neutrons flowing and calculates the ambient dose equivalent with base to this. To prove the designed code, the count rates of a spectrometer system of Bonner spheres were used with a detector of {sup 6}LiI(Eu) with 7 polyethylene spheres with diameter of 0, 2, 3, 5, 8, 10 and 12. The count rates measured with two neutron sources: {sup 252}Cf and {sup 239}PuBe were used to validate the code, the obtained results were compared against those obtained using the BUNKIUT code. We find that the reconstructed spectra present an error that is inside the limit reported in the literature that oscillates around 15%. Therefore, it was concluded that the designed code presents similar results to those techniques used at the present time. (Author)

  18. Development of an area monitor for neutrons using solid state nuclear track detector; Desenvolvimento de um monitor de area para neutrons utilizando detector solido de tracos nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Zahn, G.S.

    1994-12-31

    An area monitor for neutrons composed of the solid state nuclear track detector (SSNTD) Makrofol DE, together with a (n,{alpha}) converter, in the center of a 25 cm diameter polyethylene sphere, is developed. The optimal electrochemical etching conditions for the detection of thermal neutrons by the Makrofol DE using the BN converter are studied, leading to the choice of 55 min, at 30{sup 0} C, under a 44,2 kV.cm{sup -1} electric field with oscillation frequency of 2,0 khz. The response of this system to thermal neutrons, in the optimal conditions, is of 2,76(10)x 10{sup -3} tr/n. Changing from the BN converter to a 2,73(3)g compressed boric acid tablet this value lowers to 3,88(17)x 10{sup -4} tr/n. The performance of the whole monitor in the detection of fast neutrons is examined using the BN converter and neutrons from a {sup 241} Am Be source, with a response of 4,4(2)x 10{sup 3} tr.mSv{sup -1}.cm{sup -2} and operational limits between 7(3){mu}Sv and 5,6(2)mSv. The result of the monitoring of the control room of the IPEN Cyclotron accelerator are also presented as a final test for the viability of the practical use of the monitor. (author). 34 refs, 15 figs, 6 tabs, 1 app.

  19. Properties of the lithium carbonate for to be used as thermal neutrons detector; Propiedades del carbonato de litio para ser usado como detector de neutrones termicos

    Energy Technology Data Exchange (ETDEWEB)

    Herrera A, E.; Urena N, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2003-07-01

    In this work the dosimetric properties of the lithium carbonate used as detecting of thermal neutrons and by means of free radicals is evaluated and presented. The studied parameters that were carried out for this detector were: intensity of the Electron paramagnetic resonance signal (EPR); reproducibility, fading of the signal to ambient temperature, stability of the signal to low temperature (0 degrees); answer of zero dose and homogeneity or reliability of the data of the detector, humidity, solar light, temperature and radio sensitivity. These parameters indicate the utility that have the detectors for the estimation of fields of neutron fluences that are applicable to capture therapies by neutron-boron and, nuclear reactors. (Author)

  20. Nuclear reactor neutron shielding

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. The Physical Activity Resource Assessment (PARA instrument: Evaluating features, amenities and incivilities of physical activity resources in urban neighborhoods

    Directory of Open Access Journals (Sweden)

    Regan Gail

    2005-09-01

    Full Text Available Abstract Background Neighborhood environment factors may influence physical activity (PA. The purpose of this study was to develop and test a brief instrument to systematically document and describe the type, features, amenities, quality and incivilities of a variety of PA resources. Method The one-page Physical Activity Resource Assessment (PARA instrument was developed to assess all publicly available PA resources in thirteen urban lower income, high ethnic minority concentration neighborhoods that surrounded public housing developments (HDs and four higher income, low ethnic minority concentration comparison neighborhoods. Neighborhoods had similar population density and connectivity. Trained field coders rated 97 PA resources (including parks, churches, schools, sports facilities, fitness centers, community centers, and trails on location, type, cost, features, amenities, quality and incivilities. Assessments typically took about 10 minutes to complete. Results HD neighborhoods had a mean of 4.9 PA resources (n = 73 with considerable variability in the type of resources available for each neighborhood. Comparison neighborhoods had a mean of 6 resources (n = 24. Most resources were accessible at no cost (82%. Resources in both types of neighborhoods typically had about 2 to 3 PA features and amenities, and the quality was usually mediocre to good in both types of neighborhoods. Incivilities at PA resources in HD neighborhoods were significantly more common than in comparison neighborhoods. Conclusion Although PA resources were similar in number, features and amenities, the overall appearance of the resources in HD neighborhoods was much worse as indicated by substantially worse incivilities ratings in HD neighborhoods. The more comprehensive assessment, including features, amenities and incivilities, provided by the PARA may be important to distinguish between PA resources in lower and higher deprivation areas.

  2. RAMA Methodology for the Calculation of Neutron Fluence; Metodologia RAMA para el Calculo de la Fluencia Neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Villescas, G.; Corchon, F.

    2013-07-01

    he neutron fluence plays an important role in the study of the structural integrity of the reactor vessel after a certain time of neutron irradiation. The NRC defined in the Regulatory Guide 1.190, the way must be estimated neutron fluence, including uncertainty analysis of the validation process (creep uncertainty is ? 20%). TRANSWARE Enterprises Inc. developed a methodology for calculating the neutron flux, 1,190 based guide, known as RAMA. Uncertainty values obtained with this methodology, for about 18 vessels, are less than 10%.

  3. Verification and software validation for nuclear instrumentation; Verificacion y validacion de software para instrumentacion nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Gaytan G, E. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Salgado G, J. R. [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Barragan No. 779, Col. Narvarte, 03020 Mexico D. F. (Mexico); De Andrade O, E. [Universidad Federal de Rio de Janeiro, Caixa Postal 68509, 21945-970 Rio de Janeiro (Brazil); Ramirez G, A., E-mail: elvira.gaytan@inin.gob.mx [Comision Federal de Electricidad, Gerencia de Centrales Nucleoelectricas, Alto Lucero, Veracruz (Mexico)

    2014-10-15

    In this work is presented a Verification Methodology and Software Validation, to be applied in instruments of nuclear use with associate software. This methodology was developed under the auspices of IAEA, through the regional projects RLA4022 (ARCAL XCIX) and RLA1011 (RLA CXXIII), led by Mexico. In the first project three plans and three procedures were elaborated taking into consideration IEEE standards, and in the second project these documents were updated considering ISO and IEC standards. The developed methodology has been distributed to the participant countries of Latin America in the ARCAL projects and two related courses have been imparted with the participation of several countries, and participating institutions of Mexico like Instituto Nacional de Investigaciones Nucleares (ININ), Comision Federal de Electricidad (CFE) and Comision Nacional de Seguridad Nuclear y Salvaguardias (CNSNS). In the ININ due to the necessity to work with Software Quality Guarantee in systems for the nuclear power plant of the CFE, a Software Quality Guarantee Plan and five procedures were developed in the year 2004, obtaining the qualification of the ININ for software development for the nuclear power plant of CFE. These first documents were developed taking like reference IEEE standards and regulator guides of NRC, being the first step for the development of the methodology. (Author)

  4. El cloruro de benzalconio: inaceptable para esterilizar o desinfectar instrumental médico o dental

    Directory of Open Access Journals (Sweden)

    Acosta-Gío Enrique

    2001-01-01

    Full Text Available Objetivo. Comparar la actividad esporicida del cloruro de benzalconio (CB con la del glutaraldehído. Material y métodos. Estudio comparativo, hecho en el Laboratorio de Microbiología de la Facultad de Odontología, Universidad Nacional Autónoma de México (UNAM. Se expusieron esporas de Bacillus subtilis ATCC 9372 a estos germicidas (1 espora x µl sobre un filtro de 0.22 µm. Al completarse el tiempo de contacto, se lavaron las esporas y los filtros fueron incubados sobre agar nutritivo por 72 h a 37ºC. Resultados. El CB no eliminó las esporas de B. subtilis a la concentración de uso, ni aun al incrementar a 15 h su exposición (900 veces el tiempo recomendado. El glutaraldehído al 2% destruyó las esporas después de 10 h. La urea y el cloruro de sodio no mostraron actividad esporicida. Conclusiones. Los resultados confirman que el CB carece de actividad esporicida y ratifican que este compuesto cuaternario de amonio no tiene aplicación como agente esterilizante o como desinfectante de instrumental médico y dental. El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.html

  5. Integrating techniques for neutron dosimetry in Linac 18 MV; Integrando tecnicas para dosimetria de neutrones en un Linac de 18 MV

    Energy Technology Data Exchange (ETDEWEB)

    Ceron R, P. V.; Diaz G, J. A. I.; Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria 694, 11500 Mexico D. F. (Mexico); Paredes G, L. C. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2015-10-15

    In this paper thermoluminescent dosimetry, analytical techniques and Monte Carlo calculations were used to estimate the neutron dose equivalent in a radiotherapy room with a linear electron accelerator of 18 MV. The equivalent dose was measured at isocenter to 1.42 m of target and at the entrance of the labyrinth of the room of a Novalis Tx. The neutron detectors were constructed with pairs of thermoluminescent dosimeters TLD 600 ({sup 6}LiF: Mg, Ti) and TLD 700 ({sup 7}LiF: Mg, Ti) which are placed inside a paraffin sphere of 20 cm in diameter. These measurements enabled the calculation of equivalent dose in the gate and the source term, using the relationships contained in the NCRP-151. Through the models carried out with the code MCNPX the absorbed dose distribution with regard to depth in a paraffin phantom are included and the neutron spectrum produced by the head, taking into account the geometry and component materials. The results are in the order of neutron milli sievert by gray of X-rays (mSv/Gy x) which are in the same order as those found in other reports for different accelerators. (Author)

  6. Calibration of area monitors for neutrons used in clinical linear accelerators; Calibracao de monitores de area para neutrons usados em aceleradores lineares clinicos

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, Ana Paula; Pereira, Walsan Wagner; Patrao, Karla C. de Souza; Fonseca, Evaldo S. da, E-mail: asalgado@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Batista, Delano V.S. [Instituto Nacional do Cancer (INCa), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    This work demonstrates the complexity and the necessary cares for the realization of measurements of neutron fields in rooms for radiotherapy treatment containing clinical accelerators. The acquaintance of the technical characteristics of the monitors and the periodic calibration are actions and fundamental procedures to guarantee traceability and the reliability of measurements

  7. Iterative code for the reconstruction of the neutrons spectrum using the Bonner spheres; Codigo iterativo para la reconstruccion del espectro de neutrones usando las esferas Bonner

    Energy Technology Data Exchange (ETDEWEB)

    Reyes H, A.; Ortiz R, J. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Ingenieria Electrica, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2012-10-15

    The neutrons are the particles more difficult of detecting for their intrinsic nature. The absence of the neutrons charge makes that an interaction exists with the matter in a different way. The term radiation spectrometry can use to describe the measurement of the intensity of a radiation field with regard to the energy. The intensity distribution with relationship to the energy is commonly known as spectrum. A method to know the neutrons spectrum in the radiation fields to those that people are exposed is the use of the known system as spectrometry system of Bonner spheres, being the more used for the purposes of the radiological protection. The current interest in the electrons spectrometry has stimulated the development of several procedures to carry out the reconstruction of the spectra. During the last decades new codes have been developed such as BUNKIUT, Bums, Fruit, UMG, etc., however, these methods still present several inconveniences as the complexity in their use, the necessity of an expert user and a very near initial spectrum to the spectrum that is wanted to obtain. To solve the mentioned problems it was development the program NSDUAZ (Neutron Spectrometry and Dosimetry from Autonomous University of Zacatecas). The objective of the present work is to prove and to validate the code before mentioned making an analysis of likeness and differences and of advantages and disadvantages with relationship to the codes used at the present time. (Author)

  8. Influence of elemental concentration in soil on vegetables applying analytical nuclear techniques: k{sub 0}-instrumental neutron activation analysis and radiometry

    Energy Technology Data Exchange (ETDEWEB)

    Menezes, Maria Angela de B.C. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil). Servico de Reator e Irradiacao]. E-mail: menezes@cdtn.br; Mingote, Raquel Maia [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil). Servico de Quimica e Radioquimica; Silva, Lucilene Guerra e; Pedrosa, Lorena Gomes [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Faculdade de Farmacia

    2005-07-01

    Samples from two vegetable gardens where analysed aiming at determining the elemental concentration. The vegetables selected to be studied are grown by the people for their own use and are present in daily meal. One vegetable garden studied is close to a mining activity in a region inserted in the Iron Quadrangle (Quadrilatero Ferrifero), located in the Brazilian state of Minas Gerais. This region is considered one of the richest mineral bearing regions in the world. Another vegetable garden studied is far from this region and without any mining activity It was also studied as a comparative site. This assessment was carried out to evaluate the elemental concentration in soil and vegetables, matrixes connected with the chain food, applying the k{sub 0}-Instrumental Neutron Activation Analysis (k{sub 0}-INAA) at the Laboratory for Neutron Activation Analysis. However, this work reports only the results of thorium, uranium and rare-earth obtained in samples collected during the dry season, focusing on the influence of these elements on vegetable elemental composition. Results of natural radioactivity determined by Gross Alpha and Gross Beta measurements, are also reported. This study is related to the BRA 11920 project, entitled 'Iron Quadrangle, Brazil: assessment of health impact caused by mining pollutants through chain food applying nuclear and related techniques', one of the researches co-ordinated by the IAEA (Vienna, Austria). (author)

  9. Multielement analysis of human hair and kidney stones by instrumental neutron activation analysis with the k{sub 0}-standardization method

    Energy Technology Data Exchange (ETDEWEB)

    Abugassa, I.; Sarmani, S.B. [Department of Nuclear Science, Universiti Kebangsaan Malaysia, Bangi, Selangor (Malaysia); Samat, S.B. [Department of Physics, Universiti Kebangsaan Malaysia, Bangi, Selangor (Malaysia)

    1999-06-01

    This paper focuses on the evaluation of the k{sub 0} method of instrumental neutron activation analysis in biological materials. The method has been applied in multielement analysis of human hair standard reference materials from IAEA, No. 085, No. 086 and from NIES (National Institute for Environmental Sciences) No. 5. Hair samples from people resident in different parts of Malaysia, in addition to a sample from Japan, were analyzed. In addition, human kidney stones from members of the Malaysian population have been analyzed for minor and trace elements. More than 25 elements have been determined. The samples were irradiated in the rotary rack (Lazy Susan) at the TRIGA Mark II reactor of the Malaysian Institute for Nuclear Technology and Research (MINT). The accuracy of the method was ascertained by analysis of other reference materials, including 1573 tomato leaves and 1572 citrus leaves. In this method the deviation of the 1/E{sup 1+{alpha}} epithermal neutron flux distribution from the 1/E law (P/T ratio) for true coincidence effects of the {gamma}-ray cascade and the HPGe detector efficiency were determined and corrected for.

  10. Determination of total Pu content in a Spent Fuel Assembly by Measuring Passive Neutron Count rate and Multiplication with the Differential Die-Away Instrument

    Energy Technology Data Exchange (ETDEWEB)

    Henzl, Vladimir [Los Alamos National Laboratory; Croft, Stephen [Los Alamos National Laboratory; Swinhoe, Martyn T. [Los Alamos National Laboratory; Tobin, Stephen J. [Los Alamos National Laboratory

    2012-07-18

    A key objective of the Next Generation Safeguards Initiative (NGSI) is to evaluate and develop non-destructive assay (NDA) techniques to determine the elemental plutonium content in a commercial-grade nuclear spent fuel assembly (SFA) [1]. Within this framework, we investigate by simulation a novel analytical approach based on combined information from passive measurement of the total neutron count rate of a SFA and its multiplication determined by the active interrogation using an instrument based on a Differential Die-Away technique (DDA). We use detailed MCNPX simulations across an extensive set of SFA characteristics to establish the approach and demonstrate its robustness. It is predicted that Pu content can be determined by the proposed method to a few %.

  11. PROPUESTA PARA EL DESARROLLO DE INSTRUMENTOS DE AUTOEVALUACIÓN PARA PROGRAMAS EDUCATIVOS A DISTANCIA (PROPOSAL FOR THE DEVELOPMENT OF SELF-ASSESSMENT INSTRUMENTS FOR DISTANCE EDUCATION PROGRAMS

    Directory of Open Access Journals (Sweden)

    García Martínez Verónica

    2011-08-01

    Full Text Available Resumen:El presente trabajo expone la etapa inicial de un proyecto conjunto entre la Universidad Juárez Autónoma de Tabasco (UJAT y la Universidad Autónoma de Chiapas (UNACH, México; se trata de una estrategia diseñada para elaborar mecanismos que permitan a los programas virtuales autoevaluarse. La propuesta surge como resultado de la aplicación de un modelo de autoevaluación de programas a distancia diseñado por la Asociación Nacional de Universidades e Instituciones de Educación Superior (ANUIES y tomado como referencia para instrumentar en la UJAT, un ejercicio de autodiagnóstico durante el periodo 2008-2009. Los resultados mostraron la necesidad de pensar en mecanismos de evaluación situados en el contexto regional. La propuesta descansa, principalmente, en la revisión documental y en el panel de expertos elegidos mediante el método Delphi y Método combinado TZ. La estrategia metodológica consta de cuatro etapas: a revisión de modelos de evaluación; b la selección de expertos de dos universidades de los Estados de Tabasco y Chiapas que cuentan desde hace más de diez años con programas virtuales; c el diseño de instrumentos de auto diagnóstico y d la calificación de los instrumentos por los expertos. El reporte describe tres de las cuatro etapas del estudio. El promedio del índice de expertos en la autoevaluación fue similar en las dos universidades; se concluye, por lo tanto, que los expertos comparten un nivel de conocimiento afín, en especial en el diseño de materiales u objetos de aprendizaje, no así en indicadores de calidad estimados para la educación virtual.Abstract: The present study describes the initial stage of a joint project between the Universidad Juárez Autónoma de Tabasco (UJAT y the Universidad Autónoma de Chiapas (UNACH México. This is a strategy designed to develop mechanisms to let the distance learning programs to self - assessment. The proposal is the result of applying a self

  12. Neutron cross section measurements of water, heavy water, urine and blood for nutrition application; Medidas de secoes de choque para neutrons da agua leve, da agua pesada, urina e sangue para aplicacao em nutricao

    Energy Technology Data Exchange (ETDEWEB)

    Voi, Dante Luiz; Oliveira Ferreira, Francisco J. de [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil); Rocha, Helio F. da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Pediatria e Puericultura Marzagao Gesteira

    1997-12-01

    The present work describes the application of a method developed at the reactor physics laboratory of IEN-CNEN-RJ for the determination of body water in subjects. The method is based on neutron cross section determinations of molecular compounds. It was used the crystal neutron spectrometer installed in J-9 channel irradiation of the Argonauta reactor. Hydrogenous and deuterated samples were measured to demonstrate the viability of the method. (author). 3 refs., 1 tab.

  13. Simplified geometric model for the calculation of neutron yield in an accelerator of 18 MV for radiotherapy; Modelo geometrico simplificado para el calculo del rendimiento de neutrones en un acelerador de 18 MV para radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Paredes G, L.C.; Balcazar G, M. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico); Francois L, J.L. [FI-UNAM, 04510 Mexico D.F. (Mexico); Azorin N, J. [UAM-I, 09340 Mexico D.F. (Mexico)

    2008-07-01

    The results of the neutrons yield in different components of the bolster of an accelerator Varian Clinac 2100C of 18 MV for radiotherapy are presented, which contribute to the radiation of flight of neutrons in the patient and bolster planes. For the calculation of the neutrons yield, a simplified geometric model of spherical cell for the armor-plating of the bolster with Pb and W was used. Its were considered different materials for the Bremsstrahlung production and of neutrons produced through the photonuclear reactions and of electro disintegration, in function of the initial energy of the electron. The theoretical result of the total yield of neutrons is of 1.17x10{sup -3} n/e, considering to the choke in position of closed, in the patient plane with a distance source-surface of 100 cm; of which 15.73% corresponds to the target, 58.72% to the primary collimator, 4.53% to the levelled filter of Fe, 4.87% to the levelled filter of Ta and 16.15% to the closed choke. For an initial energy of the electrons of 18 MeV, a half energy of the neutrons of 2 MeV was obtained. The calculated values for radiation of experimental neutrons flight are inferior to the maxima limit specified in the NCRP-102 and IEC-60601-201.Ed.2.0 reports. The absorbed dose of neutrons determined through the measurements with TLD dosemeters in the isocenter to 100 cm of the target when the choke is closed one, is approximately 3 times greater that the calculated for armor-plating of W and 1.9 times greater than an armor-plating of Pb. (Author)

  14. HORACE: software for the analysis of data from single crystal spectroscopy experiments at time-of-flight neutron instruments

    CERN Document Server

    Ewings, R A; Le, M D; van Duijn, J; Bustinduy, I; Perring, T G

    2016-01-01

    The HORACE suite of programs has been developed to work with large multiple-measurement data sets collected from time-of-flight neutron spectrometers equipped with arrays of position-sensitive detectors. The software allows exploratory studies of the four dimensions of reciprocal space and excitation energy to be undertaken, enabling multi-dimensional subsets to be visualized, algebraically manipulated, and models for the scattering to simulated or fitted to the data. The software is designed to be an extensible framework, thus allowing user-customized operations to be performed on the data. Examples of the use of its features are given for measurements exploring the spin waves of the simple antiferromagnet RbMnF$_{3}$ and ferromagnetic iron, and the phonons in URu$_{2}$Si$_{2}$.

  15. Tuning the instrument resolution using chopper and time of flight at the small-angle neutron scattering diffractometer KWS-2.

    Science.gov (United States)

    Radulescu, Aurel; Székely, Noémi Kinga; Polachowski, Stephan; Leyendecker, Marko; Amann, Matthias; Buitenhuis, Johan; Drochner, Matthias; Engels, Ralf; Hanslik, Romuald; Kemmerling, Günter; Lindner, Peter; Papagiannopoulos, Aristeidis; Pipich, Vitaliy; Willner, Lutz; Frielinghaus, Henrich; Richter, Dieter

    2015-12-01

    Following demand from the user community regarding the possibility of improving the experimental resolution, the dedicated high-intensity/extended Q-range SANS diffractometer KWS-2 of the Jülich Centre for Neutron Science at the Heinz Maier-Leibnitz Center in Garching was equipped with a double-disc chopper with a variable opening slit window and time-of-flight (TOF) data acquisition option. The chopper used in concert with a dedicated high-intensity velocity selector enables the tuning at will of the wavelength resolution Δλ/λ within a broad range, from 20% (standard) down to 2%, in a convenient and safe manner following pre-planned or spontaneous decisions during the experiment. The new working mode is described in detail, and its efficiency is demonstrated on several standard samples with known properties and on a completely new crystallizable copolymer system, which were investigated using both the conventional (static) and TOF modes.

  16. Intercomparison of radiation protection devices in a high-energy stray neutron field. Part III: Instrument response

    CERN Document Server

    Silari, M; Beck, P; Bedogni, R; Cale, E; Caresana, M; Domingo, C; Donadille, L; Dubourg, N; Esposito, A; Fehrenbacher, G; Fernández, F; Ferrarini, M; Fiechtner, A; Fuchs, A; García, M J; Golnik, N; Gutermuth, F; Khurana, S; Klages, Th; Latocha, M; Mares, V; Mayer, S; Radon, T; Reithmeier, H; Rollet, S; Roos, H; Rühm, W; Sandri, S; Schardt, D; Simmer, G; Spurný, F; Trompier, F; Villa-Grasa, C; Weitzenegger, E; Wiegel, B; Wielunski, M; Wissmann, F; Zechner, A; Zielczyński, M

    2009-01-01

    The European Commission has funded within its 6th Framework Programme a three-year project (2005–2007) called CONRAD, COordinated Network for RAdiation Dosimetry. The organizational framework for this project was provided by the European radiation Dosimetry Group EURADOS. Work Package 6 of CONRAD dealt with “complex mixed radiation fields at workplaces” and in this context it organised a benchmark exercise, which included both measurements and calculations, in a stray radiation field at a high-energy particle accelerator at GSI, Germany. The aim was to intercompare the response of several types of active detectors and passive dosemeters in a well-characterised workplace field. The Monte Carlo simulations of the radiation field and the experimental determination of the neutron spectra with various Bonner Sphere Spectrometers are discussed in Rollet et al. (2008) and in Wiegel et al. (2008). This paper focuses on the intercomparison of the response of the dosemeters in terms of ambient dose equivalent. Th...

  17. HORACE: Software for the analysis of data from single crystal spectroscopy experiments at time-of-flight neutron instruments

    Science.gov (United States)

    Ewings, R. A.; Buts, A.; Le, M. D.; van Duijn, J.; Bustinduy, I.; Perring, T. G.

    2016-10-01

    The HORACE suite of programs has been developed to work with large multiple-measurement data sets collected from time-of-flight neutron spectrometers equipped with arrays of position-sensitive detectors. The software allows exploratory studies of the four dimensions of reciprocal space and excitation energy to be undertaken, enabling multi-dimensional subsets to be visualized, algebraically manipulated, and models for the scattering to simulated or fitted to the data. The software is designed to be an extensible framework, thus allowing user-customized operations to be performed on the data. Examples of the use of its features are given for measurements exploring the spin waves of the simple antiferromagnet RbMnF3 and ferromagnetic iron, and the phonons in URu2Si2.

  18. Planetary method to measure the neutrons spectrum in lineal accelerators of medical use; Metodo planetario para medir el espectro de neutrones en aceleradores lineales de uso medico

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Benites R, J. L., E-mail: fermineutron@yahoo.com [Centro Estatal de Cancerologia de Nayarit, Servicio de Seguridad Radiologica, Calzada de la Cruz 118 Sur, 63000 Tepic, Nayarit (Mexico)

    2014-08-15

    A novel procedure to measure the neutrons spectrum originated in a lineal accelerator of medical use has been developed. The method uses a passive spectrometer of Bonner spheres. The main advantage of the method is that only requires of a single shot of the accelerator. When this is used around a lineal accelerator is necessary to operate it under the same conditions so many times like the spheres that contain the spectrometer, activity that consumes enough time. The developed procedure consists on situating all the spheres of the spectrometer at the same time and to realize the reading making a single shot. With this method the photo neutrons spectrum produced by a lineal accelerator Varian ix of 15 MV to 100 cm of the isocenter was determined, with the spectrum is determined the total flow and the ambient dose equivalent. (Author)

  19. Sistema de adquisición y transmisión de datos, por fibra óptica, para un generador de neutrones.

    Directory of Open Access Journals (Sweden)

    Sergio Vergara Limon

    2010-11-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 st1:*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} Se presenta el desarrollo construcción   y aplicación de un sistema virtual de adquisición de datos basado en el uso de microcontroladores, fibra óptica y PC; que restablece la comunicación entre los módulos básicos que componen un Generador de Neutrones. Se muestra como queda modernizada la interfaz original del generador, al automatizarse la adquisición de datos sobre sus parámetros de explotación.  Se introduce el uso de la PC en el Generador de Neutrones y se establece el antecedente para extender la automatización a otros subsistemas de la instalación.  

  20. A new computation tool for neutron spectrometry and dosimetry; Una nueva herramiento de computo para la espectrometria y dosimetria de neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Martinez B, M. R.; Ortiz R, J. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Av. Ramon Lopez Velarde No. 801, Col. Centro, Zacatecas (Mexico)], e-mail: mrosariomb@yahoo.com.mx

    2009-10-15

    By using the integrated accounts of spectrometric system of Bonner spheres is possible to reconstruct the neutron spectrum using various methods such as: Monte Carlo, the parameterization and iterative methods. The response matrix, counting rates and neutron spectrum are intimately related through the integral-differential of Fredholm of first type. however, the weight of Bonner spheres system, the procedure of spectra reconstruction, the need of a expert user, the high time consumption, the need to use a reconstruction code (BUNKI, SAND, among others) and the spectrum resolution, are some of problems that this system presents. The above difficulties have motivated the development of complementary procedures such as maximum entropy, genetic algorithms and artificial neural networks. In recent years, using neural network technology has become an alternative procedure in the nuclear science research area, considering a replacement for classical techniques used for years. In previous works, was used a new method called robust design methodology of artificial neural networks, to construct various network topologies capable of solving the problems of neutron spectrometry and dosimetry, however noted that not exist tools for end-user that allow test and validate the designed networks. This paper presents the development of a software for neutronic spectrometry and dosimetry, based on information extracted from an artificial neural network designed in previous work, through the robust design methodology of artificial neural networks with the following characteristics: was designed in a user graphical interface easy to use, speed on the application execution, unlike other deconvolution codes, not is necessary to select and initial spectrum for spectrum reconstruction, as an additional element to this tool, besides spectrum, the calculation is performed simultaneous of 13 equivalent dose from just counting rates from a spectrometric system of Bonner spheres. (Author)

  1. Determination of radiation levels by neutrons in an accelerator for radiotherapy; Determinacion de niveles de radiacion por neutrones en un acelerador para radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Paredes G, L.; Salazar B, M.A. [Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, 11801 Mexico D.F. (Mexico); Genis S, R. [Fundacion Clinica Medica Sur, Puente de Piedra 150, Col. Torriello Guerra, Tlalpan 14050, Mexico D.F. (Mexico)

    1998-12-31

    It was determined the radiation levels by neutrons due to photonuclear reactions ({gamma}, n) which occur in the target, levelling filter, collimators and the small pillow blinding of a medical accelerator Varian Clinac 2100C of 18 MeV, using thermoluminescent dosemeters UD-802AS and US-809AS. The experimental values were presented for the patient level, inside and outside of the radiation field, as well as for the small pillow. (Author)

  2. Pilot study for the implantation of a high-energy neutrons field; Estudo piloto para a implantacao de um campo de neutrons de alta energia

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Jose Julio de O.; Mendes, Adriane C.; Federico, Claudio A.; Passaro, Angelo; Gaspar, Felipe de B., E-mail: jjfilos@hotmail.com, E-mail: adriane@ieav.cta.br, E-mail: claudiofederico@ieav.cta.br, E-mail: angelo@ieav.cta.br, E-mail: fbgaspar@ieav.cta.br [Instituto de Estudos Avancados (IEAv/DCTA), Sao Jose dos Campos, SP (Brazil); Pazianotto, Mauricio T., E-mail: mpazianotto@gmail.com [Instituto Tecnologico de Aeronautica (ITA/DCTA), Sao Jose dos Campos, SP (Brazil)

    2013-07-01

    In this work a theoretical study is presented for the implementation of a high-energy neutron field (14.1 MeV) produced by a neutron generator type DT (deuterium-tritium), to be installed in the premises of the Laboratorio de Radiacoes Ionizantes (LRI) of the Instituto de Estudos Avancados (IEAv). This evaluation was performed by means of computer simulation by Monte Carlo method, using the computer code MCNP5 (Monte Carlo N-Particle). The neutron spectra were simulated computationally for pre-selected points of the installation, allowing to estimate the beam quality in the positions provided for use of the direct beam. These simulations also allow assist the basement of a project to install the consistent D-T generator with the guidelines for radiation protection and radiation safety standards determined by the Comissao Nacional de Energia Nuclear (CNEN), by estimating the dose rates provided in accessible points to Individuals Occupationally Exposed (IOE) in the facility. The computational determination of spectra, fluxes and doses produced in different positions previously selected within and outside the laboratory, will serve as guidance from previous studies for the future installation of this generator in the physical facilities of the LRI.

  3. Development of a gamma ray spectrometry software for neutron activation analysis using the open source concept; Desenvolvimento de um software de espectrometria gama para analise por ativacao com neutrons utilizando o conceito de codigo livre

    Energy Technology Data Exchange (ETDEWEB)

    Lucia, Silvio Rogerio de

    2008-07-01

    This study developed a specific software for gamma ray spectra analysis for researchers of the Neutron Activation Laboratory (LAN), which was named SAANI (Instrumental Neutron Activation Analysis Software). The LAN laboratory of the Institute for Research and Nuclear Energy (IPEN-CNEN/SP), uses a multielemental analytical technique, based on irradiation of a sample by a flux of neutrons from a nuclear reactor, which induces radioactivity. The sample is then placed in a gamma-ray spectrometer, to obtain the spectrum. With free software philosophy in mind, this software will replace the existing software VISPECT / VERSION 2. The new software's main features are: a friendlier interface; easier standardization procedure carried out by LAN staff and researchers; adapted to the use of plug technology; multi platform and code free. The software was developed using the programming Python language, the library Trolltech Qt graphics and some of their scientific extensions. Preliminary results using the SANNI software were compared to those obtained with the existing software and were considered good. There were some errors in accuracy during the implementation of the software. The SAANI software has been installed in selected computers to be used for routine analysis in order to verify its strength, accuracy and usability. (author)

  4. Instrumental neutron activation analysis to determine inorganic elements in paddy soil and rice and evaluate bioconcentration factors in rice

    Directory of Open Access Journals (Sweden)

    Prapamon Seeprasert

    2017-06-01

    Full Text Available Increased anthropogenic activity, especially in thriving industries and mining activity, has led to the accumulation of inorganic elements in the soil. This study applied neutron activation analysis for the determination of inorganic element concentrations in paddy soils and quantified the nutrient value of paddy rice cultivated on various agricultural sites throughout Thailand. The determination accuracy of the elements—U, As, Sb, W, Mn, K, La, Cr, Hf, Cs, Sc, Fe, Co, Cd and Zn was assessed using National Institute of Standards and Technology standard reference materials; the results were satisfactory, showing low relative error. High analytical precision was also observed. Cadmium was selected to check the linearity of the calibration curve against a Cd standard. For a calibration curve in the range 1–9 μg, a correlation coefficient of 0.997 was found. Trace amounts of U, As, Sb, W, Mn, K, La, Cr, Hf, Cs, Sc, Fe, Co, Zn and Cd were also found in the soil samples. However, the Co, Cd, and Zn concentrations were especially high in agricultural sites in Tak province. The elemental concentrations in rice followed the order K > Zn > Mn. The data obtained are of potential benefit for the development of trace element supplementation in food.

  5. An extension of diffusion theory for thermal neutrons near boundaries; Extension del campo de validez de la teoria de difusion para neutrones termico en las proximidades de bordes

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez Rivas, J. L.

    1963-07-01

    The distribution of thermal neutron flux has been measured inside and outside copper rods of several diameters, immersed in water. It has been found that these distributions can be calculated by means of elemental diffusion theory if the value of the coefficient of diffusion is changed. this parameter is truly a diffusion coefficient, which now also depends on the diameter of the rod. Through a model an expression of this coefficient is introduced which takes account of the measurements of the author and of those reported in PUGC P/928 (1995), ANL-5872 (1959), DEGR 319 (D) (1961). This model could be extended also to plane geometry. (Author) 19 refs.

  6. A new method based on low background instrumental neutron activation analysis for major, trace and ultra-trace element determination in atmospheric mineral dust from polar ice cores

    Energy Technology Data Exchange (ETDEWEB)

    Baccolo, Giovanni, E-mail: giovanni.baccolo@mib.infn.it [Graduate School in Polar Sciences, University of Siena, Via Laterina 8, 53100, Siena (Italy); Department of Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126, Milano (Italy); INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Clemenza, Massimiliano [INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Department of Physics, University of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Delmonte, Barbara [Department of Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126, Milano (Italy); Maffezzoli, Niccolò [Centre for Ice and Climate, Niels Bohr Institute, Juliane Maries Vej, 30, 2100, Copenhagen (Denmark); Nastasi, Massimiliano; Previtali, Ezio [INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Department of Physics, University of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Prata, Michele; Salvini, Andrea [LENA, University of Pavia, Pavia (Italy); Maggi, Valter [Department of Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126, Milano (Italy); INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy)

    2016-05-30

    Dust found in polar ice core samples present extremely low concentrations, in addition the availability of such samples is usually strictly limited. For these reasons the chemical and physical analysis of polar ice cores is an analytical challenge. In this work a new method based on low background instrumental neutron activation analysis (LB-INAA) for the multi-elemental characterization of the insoluble fraction of dust from polar ice cores is presented. Thanks to an accurate selection of the most proper materials and procedures it was possible to reach unprecedented analytical performances, suitable for ice core analyses. The method was applied to Antarctic ice core samples. Five samples of atmospheric dust (μg size) from ice sections of the Antarctic Talos Dome ice core were prepared and analyzed. A set of 37 elements was quantified, spanning from all the major elements (Na, Mg, Al, Si, K, Ca, Ti, Mn and Fe) to trace ones, including 10 (La, Ce, Nd, Sm, Eu, Tb, Ho, Tm, Yb and Lu) of the 14 natural occurring lanthanides. The detection limits are in the range of 10{sup −13}–10{sup −6} g, improving previous results of 1–3 orders of magnitude depending on the element; uncertainties lies between 4% and 60%. - Highlights: • A new method based on neutron activation for the multi-elemental characterization of atmospheric dust entrapped in polar ice cores is proposed. • 37 elements were quantified in μg size dust samples with detection limits ranging from 10{sup −13} to 10{sup −6} g. • A low background approach and a clean analytical protocol improved INAA performances to unprecedented levels for multi-elemental analyses.

  7. Metal and trace element sediment assessment from Ribeira do Iguape river, Sao Paulo state, Brazil, by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Francisco J.V. de; Quinaglia, Gilson A., E-mail: franciscovc@cetesbnet.sp.gov.br, E-mail: gilsonn@cetesbnet.sp.gov.br [CETESB - Companhia Ambiental do Estado de Sao Paulo, SP (Brazil). ELTA - Setor de Analises Toxicologicas; Favaro, Deborah I.T., E-mail: defavaro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (LAN/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Laboratorio de Analise por Ativacao Neutronica; Franklin, Robson L.; Ferreira, Francisco J., E-mail: robsonf@cetesbnet.sp.gov.br, E-mail: franciscoj@cetesbnet.sp.gov.br [CETESB - Companhia Ambiental do Estado de Sao Paulo, SP (Brazil). ELAI - Setor de Quimica Inorganica

    2011-07-01

    The watershed region of the Ribeira do Iguape River and the estuarine complex of the Paranagua-Iguape- Cananeia and the various river basins located between this region and the Atlantic Ocean, is known as the Ribeira Valley. The Ribeira do Iguape River runs a total length of approximately 470 km, being the main source of fresh water in the Estuarine Complex of the Iguape-Cananeia-Paranagua (Lagamar). The Ribeira do Iguape River is the last major river in the State of Sao Paulo that has not been altered by dams. During virtually the entire 20th century, the region of the Ribeira Valley was the scene of constant environmental degradation resulting from the intense exploration and refining of lead, zinc and silver ores that were processed in the mines of the region, in a rudimentary way and without any control over environmental impacts. Since 1996, all such activities ceased, however, leaving behind a huge amount of environmental liabilities. This study aims to investigate the presence and concentration levels of metals and semi-metals arsenic (As), cadmium (Cd) and lead (Pb) in the sediment and water of aquatic systems of Ribeira do Iguape River and its tributaries, for an environmental assessment and monitoring of the region. The determination of these elements was carried out by GF AAS technique for water samples and ICP OES for the sediment samples. This study also assessed the occurrence of some major (Ca, Fe, K and Na), trace (As, Ba, Br, Co, Cs, Hf, Rb, Sb, Sc, Se, Ta, Th, U, Zn) and rare earth elements (La, Ce, Eu, Nd, Sm, Lu, Tb and Yb) by Neutron Activation Analysis (NAA). Validation of both methodologies, according to precision and accuracy, was done by reference material analyses. The results obtained for As, Cd and Pb were compared to the Canadian Environmental oriented values (TEL and PEL). The results obtained for multielemental analyses in the sediment samples were compared to UCC values (Upper Continental Crust). (author)

  8. Selection of the new position for the instrumented fuel Flip type; Seleccion de la nueva posicion para el combustible instrumentado tipo Flip

    Energy Technology Data Exchange (ETDEWEB)

    Paredes G, L.C

    1991-12-15

    It was selected and proved the new position for the instrumented fuel, in function of the smallest influence on the temperature of the fuel due to movements of the control bars, as well as to its functionality regarding their geometric localization in the core. Therefore, it intends that the instrumented fuel Flip type, pass from the position C-9 to the C-6. It was selected the turn angle of the fuel of 180 C, for to be the one that presents a smaller influence of the control bars and it allows to register the values of temperature but high. It was as the movements of the control bars they produce local interferences of the neutron flow in the fuels and that in the case of the ring C, these interferences became maximum variations of the fuel temperature of 125 C, for operations to 1 MW in the thermal column. (Author)

  9. Determination of essential and toxic elements in commercial baby foods by instrumental neutron activation analysis and atomic absorption spectrometry; Determinacao dos elementos essenciais e toxicos em alimentos comerciais infantis por analise por ativacao com neutrons e espectrometria de absorcao atomica

    Energy Technology Data Exchange (ETDEWEB)

    Vallinoto, Priscila

    2013-08-01

    The World Health Organization recommends that infants should be breast fed exclusively for at least six months after birth. After this period, it is recommended to start introducing complementary foods, in order to meet the child's nutritional, mineral and energy needs. Commercial food products for infants form an important part of the diet for many babies. Thus, it is very important that such food contains sufficient amounts of minerals. Inadequate complementary feeding is a major cause of high rates of infant malnutrition in developing countries. In this study, essential elements: Ca, Cl, Co, Cr, Fe, K, Mg, Mn, Na, Se and Zn and toxic elements: As, Cd, Hg levels were determined in twenty seven different commercial infant food product samples by Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectrometry (AAS). In order to validate both methodologies the reference material: INCT MPH-2 Mixed Polish Herbs and NIST - SRM 1577b Bovine Liver by INAA and NIST - SRM 1548th Typical Diet and NIST - SRM 1547 Peach Leaves by AAS were analyzed. The twenty seven baby food samples were acquired from Sao Paulo city supermarkets and stores. Essential and toxic elements were determined. Most of the essential element concentrations obtained were lower than the World Health Organization requirements, while concentrations of toxic elements were below the tolerable upper limit. These low essential element concentrations in these samples indicate that infants should not be fed only with commercial complementary foods. (author)

  10. Study on the mercury evolution in a laboratory multi specific aquatic system by using instrumental neutron activation analysis; Estudio de la evolucion del mercurio en un sistema acuatico de laboratorio multiespecifico utilizando analisis por activacion neutronica instrumental

    Energy Technology Data Exchange (ETDEWEB)

    Bubach, Debora; Guevara, Sergio Ribeiro; Arribere, Maria A. [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche. Lab. de Analisis por Activacion Nautronica; Pechen de d`Angelo, Ana; Ferrari, Ana; Venturino, Andres [Universidad Nacional del Comahue, Neuquen (Argentina). Facultad de Ingenieria

    1999-11-01

    A preliminary study on the evolution of mercury in the organisms of a laboratory multi specific aquatic system was performed using Instrumental Neutron Activation Analysis (INAA). Some of the possible effects of mercury toxicity were monitored by analyzing early biochemical indicators. The system consisted of an aquarium with bed sediments, aquatic macrophytes (Myriophyllum sp.), bivalves (Diplodom sp.) and exotic fish, simulating a long term contamination situation of unknown causes, where the sediments are the contaminant reservoir. Samples of the abiotic components of the system were analyzed at the beginning of the experiment, and again when the organisms were sampled. Fish carcass, kidney and liver samples, bivalve hepatopancreas, and whole macrophytes were extracted ana analyzed for mercury and other elements by INAA at the beginning of the experiment, and after 48 and 96 hours. Since some crustal elements such as Sc and La were detected in the hepatopancreas and macrophyte samples, enrichment factors for mercury, with respect to the <63 {mu}m sediment fraction, were computed to discriminate the metabolized Hg content from that associated to the particulate. The hepatopancreas index, some indicators of oxidative stress ({gamma}-Glutamyl-cysteinyl-glycine content and lipid peroxidation) and brain acetilcolinesterasa were measured as early indicators of toxicity. (author) 23 refs., 4 tabs.

  11. Characterization of ancient glass excavated in Enez (Ancient Ainos) Turkey by combined Instrumental Neutron Activation Analysis and Fourier Transform Infrared spectrometry techniques

    Energy Technology Data Exchange (ETDEWEB)

    Akyuz, Sevim, E-mail: s.akyuz@iku.edu.tr [Physics Department, Science and Letters Faculty, Istanbul Kultur University, Atakoy Campus, Bakirkoy 34156, Istanbul (Turkey); Akyuz, Tanil [Physics Department, Science and Letters Faculty, Istanbul Kultur University, Atakoy Campus, Bakirkoy 34156, Istanbul (Turkey); Mukhamedshina, Nuranya M.; Mirsagatova, A. Adiba [Institute of Nuclear Physics, Uzbek Academy of Sciences, 702132, Ulugbek, Tashkent (Uzbekistan); Basaran, Sait; Cakan, Banu [Department of Restoration and Conservation of Artefacts, Letters Faculty, Istanbul University, Vezneciler, Istanbul (Turkey)

    2012-05-15

    Ancient glass fragments excavated in the archaeological district Enez (Ancient Ainos)-Turkey were investigated by combined Instrumental Neutron Activation Analysis (INAA) and Fourier Transform Infrared (FTIR) spectrometry techniques. Multi-elemental contents of 15 glass fragments that belong to Hellenistic, Roman, Byzantine, and Ottoman Periods, were determined by INAA. The concentrations of twenty six elements (Na, K, Ca, Sc, Cr, Mn, Fe, Co, Cu, Zn, As, Rb, Sr, Sb, Cs, Ba, Ce, Sm, Eu, Tb, Yb, Lu, Hf, Ta, Au and Th), which might be present in the samples as flux, stabilizers, colorants or opacifiers, and impurities, were examined. Chemometric treatment of the INAA data was performed and principle component analysis revealed presence of 3 distinct groups. The thermal history of the glass samples was determined by FTIR spectrometry. - Highlights: Black-Right-Pointing-Pointer INAA was performed to determine elemental compositions of ancient glass fragments. Black-Right-Pointing-Pointer Basic, coloring/discoloring elements and impurities have been determined. Black-Right-Pointing-Pointer PCA discriminated the glasses depending on their chronological order. Black-Right-Pointing-Pointer The thermal history of the glass samples was determined by FTIR spectrometry.

  12. Determination of the Concentration of Essential Elements in Pleurotus Ostreatus Cultivated on Valisneria Arthiopica as a Supplementary Substrate to Sawdust using Instrumental Neutron Activation Analyses

    Directory of Open Access Journals (Sweden)

    R.G. Abrefah

    2011-11-01

    Full Text Available Mushrooms are excellent nutritional and medicinal sources in the environment. This study has sought to conduct an analysis of the concentration of the essential elements in the mushroom sample that was cultivated on three supplementary substrate compositions (25% Vallisneria aethiopica and 75% Tripochton scleroxylon, 50% Vallisneria aethiopica and 50% Tripochton scleroxylon and 75% Vallisneria aethiopica and 25% Tripochton scleroxylon using Instrumental Neutron Activation Analysis (INAA at the Ghana Research Reactor-1 facility(GHARR-1. The concentrations of the elements were detected in Pleurotus ostreatus cultivated on three different percentage substrate compositions of a mixture of Vallisneria aethiopica and Triplochiton scleroxylon. The mixture of 50% Vallisneria aethiopica and 50% Tripochton scleroxylon was best for most of the cultivation of oyster mushrooms since most of the elements detected in the samples attained the highest concentration in this substrate. The validity of the INAA technique for determination essential elements was checked by analyses of SRM 1566b (Oyster tisue and Peach leaves 1547, respectively. The mean concentrations of the nutritional elements (Al, Cs, Ca, Cu, Cr, Cl, Zn, Br, Hg, Th, Fe, K, Mg, Mn, Na and V were determined in mushrooms cultivated on three different substrate mixtures.

  13. Major and trace elemental analysis in milk powder by inductively coupled plasma-optical emission spectrometry (ICP-OES) and instrumental neutron activation analysis(INAA)

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Major and trace element in seven different kinds of milk powder were studied. The concentration of 24 elements were determined byICP-OES method, from these elements 9 elements determined by INAA. The determination of trace element contents of foodstuffs, especiallymilk as daily drink for all peoples age which being a complex food has great importance. The elemental analysis of milk is important both as anindicator of environmental contamination and because milk is a significant pathway for toxic metal intake and a source of essential nutrients forhumans. The major elements are Ca, K, Mg, Na, P and S. While trace element are B, Ba, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Sb, Se,Sn, Sr, V, W and Zn.ICP-OES technique is shown to be a powerful tool for trace determinations in powder samples. This is shown by its use for analysis of aseries of the milk powders mentioned and comparative results of other direct technique such as instrumental neutron activation analysis.Analysis of both standard reference material A-11 milk powder and NBS Orchard leaves for quality accurance had been completed, andused for a relative method calculate. The importance of the major and trace elements to human health was discussed.

  14. A new method based on low background instrumental neutron activation analysis for major, trace and ultra-trace element determination in atmospheric mineral dust from polar ice cores.

    Science.gov (United States)

    Baccolo, Giovanni; Clemenza, Massimiliano; Delmonte, Barbara; Maffezzoli, Niccolò; Nastasi, Massimiliano; Previtali, Ezio; Prata, Michele; Salvini, Andrea; Maggi, Valter

    2016-05-30

    Dust found in polar ice core samples present extremely low concentrations, in addition the availability of such samples is usually strictly limited. For these reasons the chemical and physical analysis of polar ice cores is an analytical challenge. In this work a new method based on low background instrumental neutron activation analysis (LB-INAA) for the multi-elemental characterization of the insoluble fraction of dust from polar ice cores is presented. Thanks to an accurate selection of the most proper materials and procedures it was possible to reach unprecedented analytical performances, suitable for ice core analyses. The method was applied to Antarctic ice core samples. Five samples of atmospheric dust (μg size) from ice sections of the Antarctic Talos Dome ice core were prepared and analyzed. A set of 37 elements was quantified, spanning from all the major elements (Na, Mg, Al, Si, K, Ca, Ti, Mn and Fe) to trace ones, including 10 (La, Ce, Nd, Sm, Eu, Tb, Ho, Tm, Yb and Lu) of the 14 natural occurring lanthanides. The detection limits are in the range of 10(-13)-10(-6) g, improving previous results of 1-3 orders of magnitude depending on the element; uncertainties lies between 4% and 60%.

  15. [Biliary, renal and fecal elimination and distribution of gold after a single oral administration of auranofin, quantified by the instrumental neutron activation analysis method].

    Science.gov (United States)

    Benn, H P; Schnier, C; Bauer, E; Seiler, K U; Elhöft, H; Löffler, H

    1991-01-01

    Three days after cholecystectomy, seven patients received a single dose of auranofin (5 tablets Ridaura = 4.35 mg gold). At defined time points thereafter the gold content in samples of blood, plasma, urine, bile, and feces was determined by instrumental neutron activation analysis (INAA). Maxima of the mean gold concentrations in blood (140 +/- 42 ng/ml) and plasma (173 +/- 54 ng/ml) are found 2 h after oral administration of the antirheumatic agent, after 16 h in urine (43 +/- 28 ng/ml) and bile (65 +/- 50 ng/ml), and after 24 h in erythrocytes (greater than 200 ng/ml). The mean terminal half-lives are 7.6 days (blood), 15 days (plasma), 5 days (erythrocytes), and 6.5 days (bile). The cumulative biliary gold excretion within 8 days after the administration of auranofin was 1.6%, compared with 4% and 40% for renal and fecal elimination, respectively. The gold concentration in plasma is always higher than that in bile. There is a close correlation between the areas under the concentration curves (AUC) in bile and plasma (r = 0.864).

  16. Instrumental neutron activation analysis of different products from the sugarcane industry in Pakistan--part 1: essential elements for nutritional adequacy.

    Science.gov (United States)

    Waheed, Shahida; Ahmad, Shujaat

    2008-01-01

    Jaggery, brown sugar, white sugar, and molasses collected from the local sugarcane industry of Pakistan have been analyzed for essential elements in order to estimate their nutritional adequacy. Instrumental neutron activation analysis was used to determine Ca, CI, Co, Cr, Fe, K, Mg, Mn, Na, and Zn through sequential, short, medium, and long irradiation times. Maximum concentrations for most of these elements were determined in molasses, with lower concentrations determined in jaggery and brown sugar; white sugar contained trace amounts of all essential elements. Contributions to the weekly Recommended Dietary Allowance (RDA) values for the elements were estimated only for jaggery, brown sugar, and white sugar because molasses in Pakistan is not consumed as a dietary item. Jaggery contributes the highest percentages of Cr, Mg, Mn, and Zn, whereas the highest percentages of Cl, Fe, K, and Na can be acquired from brown sugar. The contribution of white sugar to the weekly RDAs for these elements is negligible, indicating that white sugar is a poor source of the essential elements. However, the introduction of molasses to the diet can contribute to an adequate intake of these elements.

  17. Application of neutron activation analysis for the determination of essential elements in egg samples; Aplicacao da analise por ativacao com neutrons para a determinacao de elementos essenciais em amostras de ovos

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Bruna G.; Maihara, Vera A.; Avegliano, Roseane P., E-mail: brunagabrielegomes@gmail.com, E-mail: vmaihara@ipen.br, E-mail: pagliaro@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The eggs are among the twenty foods consumed by the population of the five major regions of Brazil. Among the types of eggs, there are differences in nutritional value, which can vary according to the food of the bird. This study evaluating the elements Cl, K, Mg, Mn and Na considered essential micronutrients in food, because they are fundamental in several metabolic processes necessary for the maintenance and training of the human body. We analyzed three types of eggs: egg whites, of the quail, and the colonial in cooked and raw form, using the Instrumental Neutron Activation Analysis method (INAA). The egg samples were lyophilized and pulverized before analysis. To validate the methodology, reference materials NIST RM 8415 Whole Egg Powder and NIST SRM 1567 Wheat Flour were analyzed. The samples, reference materials and standards of the elements were irradiated for 20 seconds under a thermal neutron flux of 6,6x10{sup 12} cm -2 s -1 in the nuclear research reactor IEA-R1 of IPEN-CNEN / SP. The results were consistent with the values of the Brazilian Table of Food Composition (TACO)

  18. Evaluation of the implementation and use of active personal dosimeters for neutrons in Brazil; Evaluacion de la implementacion y del uso de los dosimetros individuales activos para neutrones en el Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Castro B, C. P.; Wagner P, W.; De Souza P, K. C., E-mail: karla@ird.gov.br [Instituto de Radioprotecao e Dosimetria, Av. Salvador Allende s/n, Recreio Bandeirantes, 22780-160 Rio de Janeiro (Brazil)

    2014-08-15

    This work was conducted through of a field research based on a questionnaire sent to users of active personal dosimeters. A retrospective study of the last six years was also carried out of the services in the Neutron Metrology Laboratory (2008-2013) referent to the active personal dosimeters, taking into consideration the standards ISO-8529-3 and IEC-61526. The active personal dosimeters are defined as any instrument of individual monitoring with direct reading capacity, used by individuals exposed to ionizing radiation fields. Through research was verified that the active personal dosimeters work associated with other dosimeter types. Considering all dosimeters declared in the questionnaire, only two dosimeters (MGP brand Dmc 2000-GN model and the brand ATOMTEX model AT2503A) have conformity declaration with the international standard IEC-61526: 2005 reported by the manufacturers. (author)

  19. La Comprensión Narrativa en Edad Preescolar: Un Instrumento para su Medición Narrative Comprehension in the Preschool Age: An Assessment Instrument

    Directory of Open Access Journals (Sweden)

    Katherine Strasser

    2010-05-01

    Full Text Available La comprensión narrativa es una habilidad fundamental en la alfabetización infantil, poco atendida por investigadores y educadores por las dificultades para comprenderla y medirla, sobre todo a edades tempranas. Se reportan resultados de un estudio cuyo objetivo fue elaborar y validar un instrumento para la medición de la comprensión narrativa en niños en edad preescolar. Participaron 117 niños y niñas chilenos entre 3 años 6 meses y 5 años 1 mes de edad, pertenecientes a jardines infantiles de la Región Metropolitana. Se encontró evidencia que apoya la confiabilidad y la validez concurrente del instrumento, de fácil y rápida aplicación y codificación. Se discuten las implicancias de contar con un instrumento para medir comprensión narrativa que sea adecuado a la población preescolar chilena, así como estudios futuros necesarios para mejorar el instrumento.Narrative comprehension is a fundamental ability for children's literacy development that has been largely ignored by researchers and educators, due to the difficulties in understanding and measuring it, particularly in the early ages. The results of a study, whose goal was to construct and validate an instrument to measure narrative comprehension in preschool age children, are presented. Participants were 117 Chilean children aged 3 years and 6 months to 5 years and 1 month. Evidence was found to support the reliability and concurrent validity of the instrument, which is simple and quick to administer and code. The implications of having an instrument to measure narrative comprehension that is adequate for the Chilean preschool population are discussed, as are future studies to improve the instrument.

  20. Test of the consistency of various linearized semiclassical initial value time correlation functions in application to inelastic neutron scattering from liquid para-hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William; Liu, Jian; Miller, William H.

    2008-03-15

    The linearized approximation to the semiclassical initial value representation (LSC-IVR) is used to calculate time correlation functions relevant to the incoherent dynamic structure factor for inelastic neutron scattering from liquid para-hydrogen at 14 K. Various time correlations functions were used which, if evaluated exactly, would give identical results, but they do not because the LSC-IVR is approximate. Some of the correlation functions involve only linear operators, and others involve non-linear operators. The consistency of the results obtained with the various time correlation functions thus provides a useful test of the accuracy of the LSC-IVR approximation and its ability to treat correlation functions involving both linear and nonlinear operators in realistic anharmonic systems. The good agreement of the results obtained from different correlation functions, their excellent behavior in the spectral moment tests based on the exact moment constraints, and their semi-quantitative agreement with the inelastic neutron scattering experimental data all suggest that the LSC-IVR is indeed a good short-time approximation for quantum mechanical correlation functions.

  1. Chemical characterization of bottom sediments from Ribeira de Iguape river, Parana and Sao Paulo states, Brazil, by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Francisco J.V.; Quinaglia, Gilson A., E-mail: fjcastro@sp.gov.br, E-mail: gquinaglia@sp.gov.br [Companhia Ambiental do Estado de Sao Paulo(ELTA/CETESB), Sao Paulo, SP (Brazil). Setor de Analises Toxicologicas; Favaro, Deborah I.T., E-mail: defavaro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (LAN-CRPq/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Lab. por Ativacao Neutronica

    2013-07-01

    During several decades the Alto Vale of Ribeira region (SP-PR) suffered under lead mining activities in the region. Although in 1996 all such activities ceased, the mining activities left behind a huge amount of environmental liabilities mainly in the hydrographic basin of Ribeira de Iguape river. In the present study the chemical characterization of bottom sediments was undertaken and the concentration of the major (Ca, Fe, K and Na), trace (As, Ba, Br, Co, Cs, Hf, Rb, Sb, Ta, Th, U, Zn) and rare earth elements (La, Ce, Eu, Nd, Sm, Lu, Tb, Yb and Sc) by instrumental neutron activation analysis (INAA) were determined. The validation of the analytical methodology was performed by means of certified reference materials analyses and Z-score criterion was used. Eight points were sampled at the Ribeira de Iguape river and its majorities from Adrianopolis (Pr) (site 01) to Registro (SP) (site 08). Granulometric analyses and textural classification were undertaken in the sediment samples. The results obtained by using INAA were compared to UCC (Upper Continental Crust) reference values. The environmental tools of Enrichment Factor (EF) and Geochemical Index (GI) were used to assess the degree of metal contamination in the sediment samples. Samples from site 5 (Betari river - Iporanga, SP) presented high values for As, Sb and Zn and greater IGeo (3.1 - 5.5) and EF (>7.0) values for these elements classifying this point as highly polluted for these elements as well as a strong anthropogenic contribution. Site 7 (Ribeira river - Eldorado, SP) was considered moderately polluted for As, Br and Sb. The high concentration levels of some metals and metalloids reflect the contribution of mining activities from the past in the region. From the results it can be seen that although mining activities no longer exist since 1996, the deleterious effects in the environment are still present and strong. (author)

  2. Inelastic neutron scattering study of binding of para-hydrogen in an ultra-microporous metal-organic framework

    OpenAIRE

    Yang, Sihai; Ramirez - Cuesta, Anibal J.; Schröder, Martin

    2014-01-01

    Metal-organic framework (MOF) materials show promise for H2 storage and it is widely predicted by computational modelling that MOFs incorporating ultra-micropores are optimal for H2 binding due to enhanced overlapping potentials. We report the investigation using inelastic neutron scattering of the interaction of H2 in an ultra-microporous MOF material showing low H2 uptake capacity. The study has revealed that adsorbed H2 at 5 K has a liquid recoil motion along the channel with very little i...

  3. A new concept for an old instrument: flexible corneal scrapping spatula Um novo conceito para um antigo instrumento: espátula corneana flexível

    Directory of Open Access Journals (Sweden)

    Acacio Lima Filho

    1999-12-01

    Full Text Available We describe a new methods to produce an instrument to scrap the cornea. It is made from either a fine needle or a cannula. The material is flattened by means of a laminator or a hammer and a flat metal surface. A sandpaper is used to rough the front end and round it. The tip is slightly bent and the device is submitted to ethylene oxide for sterilization. A handle may be used to hold the instrument, which may be reusable, after washing and sterilization using local heat at the tip, or gas.Os autores descrevem um novo método para produzir um instrumento para colheita de material de córnea. Tal instrumento pode ser manufaturado com uma cânula ou agulha fina. O material é moldado de forma plana com o auxílio de um laminador, ou de um martelo e placa de metal. Lixa fina é utilizada para arredondar as bordas e a ponta é ligeiramente dobrada. Um cabo pode ser adicionado de modo a facilitar a manipulação do instrumento, que pode ser reutilizado após lavagem e esterilização local na ponta do metal, ou por óxido de etileno.

  4. Novos Desafios para o Instrumental Antropológico de Identificação de Grupos Indí­Genas Emergentes

    Directory of Open Access Journals (Sweden)

    Edward Mantoanelli Luz

    2008-08-01

    Full Text Available Mudanças positivas no quadro indigenista brasileiro provocaram, a partir do fim da década de 1980, um crescente movimento nacional de comunidades que passaram a lutar pelo reconhecimento de sua alteridade indígena e de seus respectivos direitos. A comunidade antropológica viu-se surpreendida diante dessa avalanche de demandas e, em resposta, imediatamente se utilizou dos critérios teóricos propostos pelo antropólogo Fredrick Barth para o estabelecimento das fronteiras étnicas de grupos emergentes. Este ensaio é um alerta para o perigo de interpretações extremistas e utilizações exclusivistas do instrumental teórico barthiano como único critério identitário. Tomando por base as experiências resultantes de sua aplicação no caso cocama, do Alto Solimões, este trabalho pretende revelar a fragilidade do instrumental e a necessidade de acréscimos teóricos e práticos para uma análise equilibrada e imparcial de casos de grupos indígenas emergentes.

  5. Advances in neutron tomography

    Indian Academy of Sciences (India)

    W Treimer

    2008-11-01

    In the last decade neutron radiography (NR) and tomography (NCT) have experienced a number of improvements, due to the well-known properties of neutrons interacting with matter, i.e. the low attenuation by many materials, the strong attenuation by hydrogenous constituent in samples, the wavelength-dependent attenuation in the neighbourhood of Bragg edges and due to better 2D neutron detectors. So NR and NCT were improved by sophisticated techniques that are based on the attenuation of neutrons or on phase changes of the associated neutron waves if they pass through structured materials. 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. Now one can present 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 neutrons. Magnetic fields in different coils and in samples (superconductors) at low temperatures could be visualized. In this lecture a summary about standard signals (attenuation) and the more `sophisticated' imaging signals as refraction, small angle scattering and polarized neutrons will be given.

  6. Neutron activation analysis for determining of inorganic trace elements in by-products of soybean, cotton, corn, wheat, sorghum and rice; Aplicacao da analise por ativacao com neutrons para determinacao de elementos inorganicos em subprodutos da soja, algodao, milho, trigo, sorgo e arroz

    Energy Technology Data Exchange (ETDEWEB)

    Teruya, Carla M.; Armelin, Maria Jose [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Silva Filho, Jose Cleto [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Ciencias Animais; Silva, Aliomar G. [Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Sao Carlos, SP (Brazil). Centro de Pesquisa de Pecuaria do Sudeste

    1999-11-01

    In the present paper the instrumental neutron activation analysis was applied to determine some essential and toxic elements in six agroindustrial by-products utilized to feed animal. The accuracy of the method was evaluated by means of reference material analysis. In general, the precision of the method was lower than 10% and the accuracy near to 5%. (author) 7 refs., 1 tab.

  7. Confiabilidade do Instrumento para Classificação de Idosos quanto à Capacidade para o Autocuidado Reliability of the Instrument for Classifying Elderly People's Capacity for Self-care

    Directory of Open Access Journals (Sweden)

    Maria Helena Morgani de Almeida

    2008-04-01

    Full Text Available OBJETIVO: Avaliar a confiabilidade do Instrumento para Classificação de Idosos quanto à Capacidade para o Autocuidado, desenvolvido para auxiliar o terapeuta ocupacional na atenção a idosos em unidades básicas de saúde. MÉTODOS: Foram realizados testes de estabilidade e consistência interna. Para validação do Instrumento, os testes foram aplicados à amostra de 30 indivíduos com 60 anos ou mais, em dois momentos. A análise estatística foi realizada a partir de agrupamentos criteriosos de respostas, o que levou à formulação de uma versão simplificada do Instrumento. A estabilidade desta versão foi avaliada pelo coeficiente kappa e a consistência interna pelo coeficiente alpha de Cronbach. RESULTADOS: A estabilidade variou de moderada a excelente. A consistência interna foi verificada somente para áreas que se mostraram adequadas para o uso da metodologia baseada no cálculo do alpha de Cronbach: três das seis questões da área "perfil social" e os blocos das atividades básicas e instrumentais de vida diária da área "capacidade funcional", respectivamente com nove e oito atividades. CONCLUSÕES: Após os testes de estabilidade e consistência interna, o Instrumento possibilita classificação sucinta e simplificada de idosos quanto à capacidade funcional para atividades básicas e instrumentais e sua caracterização quanto aos demais aspectos do autocuidado. Evidências acerca de sua confiabilidade e validade podem ser ampliadas por meio de novos estudos.OBJECTIVE: To evaluate the reliability of an instrument for classifying elderly people regarding their capacity for self-care, which was developed to assist occupational therapists in attending elderly people at primary healthcare units. METHODS: Stability and internal consistency tests were carried out. To validate the instrument, tests were applied to a sample of 30 individuals aged 60 years and over, on two occasions. The statistical analysis was performed after

  8. Measurements of thermal neutron fluence in the bunker of a cyclotron for PET isotope production; Medidas de fluencia de neutrones termicos en el bunker de un ciclotron de produccion de isotopos para PET

    Energy Technology Data Exchange (ETDEWEB)

    Mendez Villafane, R.; Sansoloni florit, F.; Lagares gonzalez, J. L.; Llop Roig, J.; Guerrero Araque, J. E.; Muniz Gutierrez, J. L.; Perez Morales, J. M.

    2011-07-01

    To measure the neutron spectrum has been used spectrometry system based on Bonner spheres with Au flakes as thermal neutron detector at its center while the results are still pending and will be analyzing another job.

  9. Instrumental neutron activation analysis with Compton suppression for the evaluation of foodstuff composition;Supressao Compton na analise por ativacao neutronica instrumental de produtos agricolas destinados a alimentacao humana

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Luis Gustavo Cofani dos

    2004-07-01

    Instrumental neutron activation analysis (INAA) is a good option for studying chemical composition of food, allowing the simultaneous determination of several elements. However, the incomplete deposition of gamma-ray energies in the detector crystal due to Compton scatter can elevate the spectrum baseline making difficult the determination of some elements. The problem is particularly important for samples having high activities of radionuclides emitting gamma-rays with energies higher than those to be measured. For such cases, the use of a Compton suppression system can improve the detection limits. Here, the application of a suppression system for the analysis of foodstuff is evaluated. Measurements were carried out with a hyper pure germanium detector with 55 % relative efficiency for the photopeak 1332 keV of {sup 60}Co, working in anti-coincidence with two sodium iodine guard detectors (annulus and plug). Suppressed and unsuppressed spectra were simultaneously acquired. Initially, the overall system performance on the reduction of the Compton region was tested using {sup 137}Cs. Measuring between 358 and 382 keV, the higher suppression factor was 5.97, being observed a large variation according to the energy region selected for the determination. Reductions were noticed for the suppression factor resulting from increases on counting rate and source-detector distance. The suppression system showed to be stable during twenty weeks of periodic verifications. To evaluate the system performance on real sample analysis, several types and commercial brands of rice, potatoes, beans, peas, chickpeas and lentil were taken. After drying and grinding, samples were irradiated at a thermal neutron flux of 1x10{sup 13} cm{sup -2} s{sup -1} for 8 hours, in the nuclear research reactor IEA-R1 from IPEN/CNEN (Instituto de Pesquisas Energeticas e Nucleares). Each sample was measured after decay periods of about 3, 7, 15 and 40 days. Analysis was conducted by the k{sub 0} method

  10. A neutron-sensitive image intensifier-television system

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, J.B.; Smith, H.G.; Willems, R.A.

    1989-01-01

    A neutron-sensitive, image intensifier-digital television system has been developed for area recording of weak patterns in neutron scattering studies. It can also be used as a low resolution neutron radiography instrument. 8 refs., 1 fig.

  11. Neutron reflectometry

    DEFF Research Database (Denmark)

    Klösgen-Buchkremer, Beate Maria

    2014-01-01

    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...... of desired information. In the course, an introduction into the method and an overview on selected instruments at large scale facilities will be presented. Examples will be given that illustrate the potential of the method, mostly based on organic films. Results from the investigation of layered films...... and the detection on nanoscopic roughnesses will be shown. The potential of neutron reflectometry is not only of academic origin. It may turn out to be useful in the design and development of new functional materials even though it will never develop into a standard method to be applied in the product control...

  12. El cloruro de benzalconio: inaceptable para esterilizar o desinfectar instrumental médico o dental Benzalkonium chloride is unacceptable to sterilize or disinfect medical or dental instruments

    Directory of Open Access Journals (Sweden)

    Enrique Acosta-Gío

    2001-12-01

    Full Text Available Objetivo. Comparar la actividad esporicida del cloruro de benzalconio (CB con la del glutaraldehído. Material y métodos. Estudio comparativo, hecho en el Laboratorio de Microbiología de la Facultad de Odontología, Universidad Nacional Autónoma de México (UNAM. Se expusieron esporas de Bacillus subtilis ATCC 9372 a estos germicidas (1 espora x µl sobre un filtro de 0.22 µm. Al completarse el tiempo de contacto, se lavaron las esporas y los filtros fueron incubados sobre agar nutritivo por 72 h a 37ºC. Resultados. El CB no eliminó las esporas de B. subtilis a la concentración de uso, ni aun al incrementar a 15 h su exposición (900 veces el tiempo recomendado. El glutaraldehído al 2% destruyó las esporas después de 10 h. La urea y el cloruro de sodio no mostraron actividad esporicida. Conclusiones. Los resultados confirman que el CB carece de actividad esporicida y ratifican que este compuesto cuaternario de amonio no tiene aplicación como agente esterilizante o como desinfectante de instrumental médico y dental. El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.htmlObjective. To compare the sporicidal activity of benzalkonium chloride (BKC with that of glutaraldehyde. Material and Methods. A comparative study was conducted at the microbiology laboratory of Facultad de Odontología, Universidad Nacional Autónoma de México. Bacillus subtilis ATCC 9372 spores were exposed to these germicides (1 spore x mL on a 0.22 mm filter. After completing the contact time the spores were washed and the filters were incubated on nutrient agar for 72 h at 37ºC. Results. BKC did not eliminate B. subtilis spores at the concentration used, not even after increasing contact time to 15 h (900-fold the recommended time. Two percent glutaraldehyde destroyed spores only after 10 h of contact. Urea and sodium chloride showed no sporicidal activity. Conclusions. The results confirm that BKC lacks sporicidal

  13. CORRELACIÓN, LENGUA Y REALIDAD COMO ESTRATEGIA PARA LA ENSEÑANZA DEL INGLÉS INSTRUMENTAL EN LAS CIENCIAS MATEMÁTICAS

    Directory of Open Access Journals (Sweden)

    Ana Finol de Govea

    1999-07-01

    Full Text Available Esta investigación trata de la implementación de dos estrategias para la enseñanza de inglés instrumental; primero, centrar el aprendizaje en contenidos relevantes; y luego aplicar la interacción grupal para interrelacionar destrezas de lectura y conocimientos del área de estudio. La investigación tiene como bases teóricas los planteamientos formulados por S. Krashen (1985; C. Candlin (1987; B. Mohan (1989; y J. Read (1990. La investigación es descriptiva/experimental, realizada durante el primero y segundo semestre de 1995 en el Proyecto de Matemática y Física de la Universidad Rafael María Baralt en Cabimas, Venezuela. La investigación arrojó el 73.7% de estudiantes aprobados.

  14. Asentamientos poblacionales periféricos más seguros. Instrumental para el diseño y evaluación de la calidad ambiental

    Directory of Open Access Journals (Sweden)

    Graciela Gómez Ortega

    2011-06-01

    Full Text Available La vulnerabilidad de un asentamiento ante cualquier situación y ámbito territorial, es una preocupación, debido entre otras cuestiones a su fuerte influencia en las políticas de desarrollo de gestión frente a desastres o eventos adversos externos que afectan el normal desarrollo de las personas; de ahí que diagnosticar la calidad ambiental de una urbanización en áreas espaciales específicas, como es el caso de las urbanizaciones periféricas, posibilita analizar aquellos factores que influyen en la vulnerabilidad de estas y formular recomendaciones para implementar políticas ambientales que mitiguen los riesgos. Partiendo de que la vulnerabilidad es una noción dinámica que examina los factores de riesgos, se presenta un instrumental para la evaluación ambiental de los Asentamientos Poblacionales Periféricos (APP, en las condiciones particulares de la ciudad Santiago de Cuba, donde se ha considerado esta componente dentro de sus indicadores evaluativos. Se expone el instrumental de referencia y su sistema categorial: variables, subvariables; parámetros evaluativos y escala de valores, lo que constituye la esencia del instrumental teórico diseñado; de igual forma se presentan los histogramas y matrices que conforman el instrumental práctico de evaluación. El mismo servirá para evaluar asentamientos en funcionamiento y para el diseño de nuevos, pudiendo ser generalizado a otros territorios.   Palabras claves: Asentamientos poblacionales periféricos;calidad ambiental; vulnerabilidad.The vulnerability of settlement before any situation and territorial scope, is a concern, due inter alia to their strong influence on the development policies of management to disaster or adverse external events affecting the normal development of the people; Summary to diagnose the environmental quality of urbanization in a discrete space, as it is the case of the peripheral housing estates, allows analyze those factors that influence the

  15. Semiautomatic exchanger of samples for carry out neutron activation analysis; Intercambiador semiautomatico de muestras para realizar analisis por activacion neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar H, F.; Quintana C, G. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Torres R, C. E.; Mejia J, J. O., E-mail: fortunato.aguilar@inin.gob.mx [Instituto Tecnologico de Toluca, Av. Tecnologico s/n, Ex-Rancho La Virgen, Metepec, Estado de Mexico (Mexico)

    2015-09-15

    In this paper the design methodology and implementation of a semiautomatic exchanger of samples for the Analysis Laboratory by Neutron Activation of the Reactor department is presented. Taking into account the antecedents, the necessities of improvement are described, as well as the equipment that previously contained the Laboratory. The project of the semiautomatic exchanger of samples was developed at Instituto Nacional de Investigaciones Nucleares, with its own technology to increase independence from commercial equipment. Each element of the semiautomatic exchanger of samples is described both in the design phase as construction. The achieved results are positive and encouraging for the fulfillment of the proposed objective that is to increase the capacity of the Laboratory. (Author)

  16. Adaptação transcultural para o português brasileiro do Parental Bonding Instrument (PBI Cross-cultural adaptation of Parental Bonding Instrument (PBI to Brazilian Portuguese

    Directory of Open Access Journals (Sweden)

    Simone Hauck

    2006-08-01

    Full Text Available OBJETIVO: O artigo apresenta a adaptação transcultural do Parental Bonding Instrument, um questionário auto-aplicável desenvolvido em 1979 e usado desde então para avaliar a percepção da qualidade do vínculo com os pais até os 16 anos. MÉTODO: Foram realizadas as etapas de equivalência conceitual, equivalência dos itens, equivalência semântica, equivalência operacional, equivalência funcional e aprovação da versão final pelo autor original do instrumento. RESULTADOS: Os critérios de equivalência foram satisfeitos, tendo a versão final sido aprovada pelo autor do instrumento original. CONCLUSÃO: A adaptação do Parental Bonding Instrument disponibiliza para uso um instrumento que já demonstrou ser extremamente útil em pesquisas de risco e resiliência nas últimas décadas, ao avaliar a percepção de características do comportamento dos pais tradicionalmente associadas ao desenvolvimento da personalidade.OBJETIVE: This article aims to present a cross-cultural adaptation of the Parental Bonding Instrument to Brazilian Portuguese. It is a self-administered questionnaire developed in 1979, which has been used since then to measure the subjective experience of being parented to the age of 16 years. METHOD: The following steps were performed: conceptual equivalence, item equivalence, semantic equivalence, operational equivalence, functional equivalence, and approval of the final version by the author of the original instrument. RESULTS: The study has reached the objectives of equivalence, and the final Brazilian Portuguese version has been approved by the original author. CONCLUSION: The study provides a Brazilian Portuguese version of an instrument that has been proven extremely useful in risk and resilience researches over the past decades, assessing the perception of parental characteristics traditionally related to personality development.

  17. Mineralogy and instrumental neutron activation analysis of seven National Bureau of Standards and three Instituto de Pesquisas Tecnologicas clay reference samples

    Science.gov (United States)

    Hosterman, John W.; Flanagan, F.J.; Bragg, Anne; Doughten, M.W.; Filby, R.H.; Grimm, Catherine; Mee, J.S.; Potts, P.J.; Rogers, N.W.

    1987-01-01

    The concentrations of 3 oxides and 29 elements in 7 National Bureau of Standards (NBS) and 3 Instituto de Pesquisas Techno16gicas (IPT) reference clay samples were etermined by instrumental neutron activation analysis. The analytical work was designed to test the homogeneity of constituents in three new NBS reference clays, NBS-97b, NBS-98b, and NBS-679. The analyses of variance of 276 sets of data for these three standards show that the constituents are distributed homogeneously among bottles of samples for 94 percent of the sets of data. Three of the reference samples (NBS-97, NBS-97a, and NBS-97b) are flint clays; four of the samples (NBS-98, NBS-98a, NBS-98b, and IPT-32) are plastic clays, and three of the samples (NBS-679, IPT-28, and IPT-42) are miscellaneous clays (both sedimentary and residual). Seven clays are predominantly kaolinite; the other three clays contain illite and kaolinite in the approximate ratio 3:2. Seven clays contain quartz as the major nonclay mineral. The mineralogy of the flint and plastic clays from Missouri (NBS-97a and NBS-98a) differs markedly from that of the flint and plastic clays from Pennsylvania (NBS-97, NBS-97b, NBS-98, and NBS-98b). The flint clay NBS-97 has higher average chromium, hafnium, lithium, and zirconium contents than its replacement, reference sample NBS-97b. The differences between the plastic clay NBS-98 and its replacement, NBS-98b, are not as pronounced. The trace element contents of the flint and plastic clays from Missouri, NBS-97a and NBS-98a, differ significantly from those of the clays from Pennsylvania, especially the average rare earth element (REE) contents. The trace element contents of clay sample IPT-32 differ from those of the other plastic clays. IPT-28 and IPT-42 have some average trace element contents that differ not only between these two samples but also from all the other clays. IPT-28 has the highest summation of the average REE contents of the 10 samples. The uranium content of NBS-98a, 46

  18. CDM (Clean development mechanism) like instrument for sustainable development?; MDL (mecanismo de desenvolvimento limpo) como instrumento para o desenvolvimento sustentavel?

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Kamyla Borges da; Walter, Arnaldo Cesar Silva; Varella, Fabiana Karla de Oliveira; Streb, Cleci Schalemberger [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Fac. de Engenharia Mecanica. Curso de Pos-Graduaco em Planejamento de Sistemas Energeticos], e-mail: kamyla@fem.unicamp.br

    2004-07-01

    The intensification of the greenhouse effect, caused mainly by the anthropogenic activities, such as the intensive use of fossil fuels, reveals itself as a challenge to governments and international organizations. The institution of an international legal framework, resulted from the implementation of the United Nations Framework Convention on Climate Change and the Kyoto Protocol, is allowing the development of some mitigation instruments, such as the clean development mechanism (CDM). The article's purpose is to assess the social and economic aspects that are leading to the climate change process and to analyze the instruments foreseen in the international legal system to face this global concern, in special, the CDM as a tool to achieve sustainable development practices. In this way, the authors aims to demonstrate the connection and interdependence between those instruments and the sustainable development. (author)

  19. J-PARC and the prospective neutron sciences

    Indian Academy of Sciences (India)

    Masatoshi Arai

    2008-10-01

    Overview of the neutron target system, instrument suite and perspective neutron sciences of J-PARC are described. The neutron facility of J-PARC, JSNS, will be operated from May 2008. JSNS will be a 1 MW pulsed spallation neutron source. About 10 high performance instruments are under construction to be ready by the Day-One.

  20. Low-cost microprocessed instrument for evaluating soil temperature profile Instrumento microprocessado de baixo custo para avaliação da temperatura em perfil de solo

    Directory of Open Access Journals (Sweden)

    PAULO ESTEVÃO CRUVINEL

    2000-11-01

    Full Text Available This paper describes a low-cost microprocessed instrument for in situ evaluating soil temperature profile ranging from -20.0°C to 99.9°C, and recording soil temperature data at eight depths from 2 to 128 cm. Of great importance in agriculture, soil temperature affects plant growth directly, and nutrient uptake as well as indirectly in soil water and gas flow, soil structure and nutrient availability. The developed instrument has potential applications in the soil science, when temperature monitoring is required. Results show that the instrument with its individual sensors guarantees ±0.25°C accuracy and 0.1°C resolution, making possible localized management changes within decision support systems. The instrument, based on complementary metal oxide semiconductor devices as well as thermocouples, operates in either automatic or non-automatic mode.Este artigo descreve um instrumento microprocessado de baixo custo para avaliação in situ da temperatura em perfil de solo na faixa de -20,0°C a 99,9°C com armazenagem de dados de até oito profundidades, de 2 a 128 centímetros. A temperatura do solo é de grande importância para o crescimento de plantas, absorção de nutrientes, fluxo de gases e estrutura. O instrumento desenvolvido encontra várias aplicações na área da ciência do solo, onde o monitoramento de temperatura do solo é requerido. Resultados mostram que a caracterização do instrumento e seus sensores individuais garantem uma acurácia de ±0,25°C e uma resolução de 1,0°C. Também proporciona a produtores ou pesquisadores a oportunidade do manejo localizado para sistemas de tomada de decisão. O instrumento é baseado em dispositivos semicondutores com tecnologia de óxido metálico complementar e termopares. E pode operar tanto no modo manual quanto no modo automático.

  1. Validación de un instrumento para medir competencias conductuales en personas VIH positivas Validation of an instrument to measure behavioral competencies in HIV+ persons

    Directory of Open Access Journals (Sweden)

    Julio Alfonso Piña-López

    2003-08-01

    Full Text Available OBJETIVO: Estudiar la confiabilidad y validez de un instrumento que mide competencias conductuales en personas que viven con VIH/sida. MATERIAL Y MÉTODOS: Estudio transversal, efectuado en los meses de noviembre y diciembre de 2002 en la ciudad de Hermosillo, estado de Sonora, México. En él se manejó un instrumento que consta de 24 reactivos y fue aplicado a una muestra de 60 personas VIH positivas que reciben atención en dos instituciones del sector salud, México. Se emplearon los siguientes procedimientos estadísticos: para la discriminación de los reactivos se utilizó la prueba t; para la validez de constructo se efectuó un análisis de su estructura factorial, mientras que para la confiabilidad se recurrió al estadístico alfa de Cronbach. RESULTADOS: Excepto dos reactivos, el resto discriminó correctamente; el análisis factorial arrojó tres factores, que en su conjunto explican 47.99% de la varianza, y un índice conformado por dos reactivos; finalmente, la encuesta en su conjunto alcanzó un alfa de Cronbach de 0.856. CONCLUSIONES: Este instrumento tiene las ventajas de ser claro, con una buena discriminación de los reactivos y de poseer validez de constructo.OBJECTIVE: To assess the reliability and validity of an instrument to measure behavioral competences in HIV/AIDS-infected persons. MATERIAL AND METHODS: A cross-sectional study was conducted in November and December 2002 in Hermosillo, Sonora State, Mexico. An instrument consisting of 24 items was applied to 60 HIV-positive subjects who received health care through two Mexican Ministry of Health institutions. Statistical analysis consisted of Student s t test for item discrimination and Cronbach s alpha for testing construct reliability. RESULTS: All but two items were able to discriminate correctly; factorial analysis resulted in three factors that jointly accounted for 48% of the variance. Finally a two-item index was obtained. The survey as a whole attained a

  2. SINGLE CRYSTAL NEUTRON DIFFRACTION.

    Energy Technology Data Exchange (ETDEWEB)

    KOETZLE,T.F.

    2001-03-13

    Single-crystal neutron diffraction measures the elastic Bragg reflection intensities from crystals of a material, the structure of which is the subject of investigation. A single crystal is placed in a beam of neutrons produced at a nuclear reactor or at a proton accelerator-based spallation source. Single-crystal diffraction measurements are commonly made at thermal neutron beam energies, which correspond to neutron wavelengths in the neighborhood of 1 Angstrom. For high-resolution studies requiring shorter wavelengths (ca. 0.3-0.8 Angstroms), a pulsed spallation source or a high-temperature moderator (a ''hot source'') at a reactor may be used. When complex structures with large unit-cell repeats are under investigation, as is the case in structural biology, a cryogenic-temperature moderator (a ''cold source'') may be employed to obtain longer neutron wavelengths (ca. 4-10 Angstroms). A single-crystal neutron diffraction analysis will determine the crystal structure of the material, typically including its unit cell and space group, the positions of the atomic nuclei and their mean-square displacements, and relevant site occupancies. Because the neutron possesses a magnetic moment, the magnetic structure of the material can be determined as well, from the magnetic contribution to the Bragg intensities. This latter aspect falls beyond the scope of the present unit; for information on magnetic scattering of neutrons see Unit 14.3. Instruments for single-crystal diffraction (single-crystal diffractometers or SCDs) are generally available at the major neutron scattering center facilities. Beam time on many of these instruments is available through a proposal mechanism. A listing of neutron SCD instruments and their corresponding facility contacts is included in an appendix accompanying this unit.

  3. Inelastic neutron scattering study of binding of para-hydrogen in an ultra-microporous metal-organic framework

    Science.gov (United States)

    Yang, Sihai; Ramirez-Cuesta, Anibal J.; Schröder, Martin

    2014-01-01

    Metal-organic framework (MOF) materials show promise for H2 storage and it is widely predicted by computational modelling that MOFs incorporating ultra-micropores are optimal for H2 binding due to enhanced overlapping potentials. We report the investigation using inelastic neutron scattering of the interaction of H2 in an ultra-microporous MOF material showing low H2 uptake capacity. The study has revealed that adsorbed H2 at 5 K has a liquid recoil motion along the channel with very little interaction with the MOF host, consistent with the observed low uptake. The low H2 uptake is not due to incomplete activation or decomposition as the desolvated MOF shows CO2 uptake with a measured pore volume close to that of the single crystal pore volume. This study represents a unique example of surprisingly low H2 uptake within a MOF material, and complements the wide range of studies on systems showing higher uptake capacities and binding interactions.

  4. Calibration of a TLD system to estimate personal doses in fields of gamma-neutrons radiation; Calibracion de un sistema TLD para estimar dosis personal en campos de radiacion gamma-neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Villegas, E.N.; Somarriba, S.I., E-mail: evillegas@unan.edu.ni [Lab. de Fisica de Radiaciones y Metrologia, Universidad Nacional Autonoma de Nicaragua (Nicaragua)

    2016-07-01

    Currently Nicaragua has no personal neutron dosimetry system. The calibration of a batch of albedo neutron dosimeters consisting of two pairs of {sup 6}LiF and {sup 7}LiF (Mg, Ti) detectors was done. The dosimeter and reader sensitivities were obtained using a {sup 137}Cs source, and a neutron calibration factor was found with a {sup 241}AmBe source. Reproducibility and homogeneity tests were performed, and the detection limit of the system was determined. This calibration will allow the beginning of neutron personal monitoring in the country. (author)

  5. Structural and energetical studies of the adsorption of para and meta-isomers of xylene on pre-hydrated zeolite BaX. Characterization by neutron diffraction and temperature programmed desorption; Etude structurale et energetique de l'adsorption des isomeres para- et meta- du xylene dans la zeolithe BaX prehydratee. Caracterisation par diffraction des neutrons et thermodesorption programmee

    Energy Technology Data Exchange (ETDEWEB)

    Pichon, Ch.

    1999-10-19

    The separation of p-xylene from C{sub 8} aromatics is performed industrially by selective adsorption on zeolitic materials. FAU-type zeolites are currently used for this separation and especially the partially hydrated BaX. The aim of this work is to characterize from a structural (by low temperature neutron powder diffraction) and an energetical (by temperature programmed desorption) point of view, the adsorption of para- and meta- isomers of xylene, for different fillings, as pure substances as well as mixtures, on pre-hydrated zeolite BaX. The influence of the water pre-adsorption on xylene adsorption selectivity is carefully discussed. The crystalline structure of the zeolite BaX (framework and compensation of charge cations) and of the adsorbed phase (water, p- and m-xylene molecules) are completely characterized by neutron diffraction. The location and the distribution of water and xylene molecules on their adsorption sites is especially followed as a function of the filling of the zeolite and of the composition of the adsorbed phase. Microscopic measurements were correlated to the energetical analysis (at a macroscopic level) in order to obtain a consistent description of adsorption phenomenon and to propose a possible origin for adsorption selectivity.

  6. Validação de um Instrumento para Mensurar o Valor da Tecnologia de Informação (TI para as Organizações Validation of an instrument to mesure the business value of Information Technology

    Directory of Open Access Journals (Sweden)

    Mateus Michelini Beltrame

    2010-02-01

    Full Text Available Ainda existem dúvidas entre pesquisadores e executivos sobre quais são os tipos de benefícios proporcionados pela TI, em outras palavras, como avaliar o valor da TI para as organizações. A TI não é simplesmente uma ferramenta para automatizar processos existentes, mas é principalmente uma facilitadora de mudanças organizacionais que podem levar a ganhos adicionais de produtividade. Este artigo apresenta a validação de um instrumento para mensurar o valor da TI a partir da percepção de gestores das áreas de TI e negócios. A natureza multidimensional do retorno dos investimentos em TI sugere que categorias distintas de mensuração sejam criadas de modo a avaliar diferentes aspectos. O instrumento de pesquisa está baseado na combinação de cinco dimensões distintas de benefícios proporcionados pela TI às organizações.There are still many researchers who are insure about how to evaluate the benefits of InformationTechnology in organizations. This article proposes and validate an instrument for measure the benefits of IT on a multidimentional basis.

  7. A review on neutron reflectometry

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Soo; Lee, Chang Hee; Shim, Hae Seop; Seong, Baek Seok

    1999-03-01

    This report contains principle and characteristic of neutron reflectometry. Therefore, in case of operating neutron reflectometer at HANARO in future, it will be a reference to the user who wishes to use the instrument effectively. Also, the current situation of neutron reflectometer operating in the world was examined. The detail of neutron reflectometer such as GANS(MURR), ADAM(ILL), POSY II(ANL), ROG(IRI) was described. The recent research situation on neutron reflectometry was also examined and it helps us to determine research field. (author)

  8. Neutron proton crystallography station (PCS)

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Zoe [Los Alamos National Laboratory; Kovalevsky, Andrey [Los Alamos National Laboratory; Johnson, Hannah [Los Alamos National Laboratory; Mustyakimov, Marat [Los Alamos National Laboratory

    2009-01-01

    The PCS (Protein Crystallography Station) at Los Alamos Neutron Science Center (LANSCE) is a unique facility in the USA that is designed and optimized for detecting and collecting neutron diffraction data from macromolecular crystals. PCS utilizes the 20 Hz spallation neutron source at LANSCE to enable time-of-flight measurements using 0.6-7.0 {angstrom} neutrons. This increases the neutron flux on the sample by using a wavelength range that is optimal for studying macromolecular crystal structures. The diagram below show a schematic of PCS and photos of the detector and instrument cave.

  9. Instrumento para avaliação de detergentes enzimáticos Instrumento para evaluación de detergentes enzimáticos An instrument for evaluating enzymatics detergents

    Directory of Open Access Journals (Sweden)

    Denise Rodrigues Costa Schmidt

    2008-06-01

    Full Text Available Estudo de desenvolvimento metodológico que teve por objetivo construir um instrumento de avaliação de detergentes enzimáticos e analisar a ação dos produtos sobre os instrumentais. O instrumento foi submetido à análise de três juízes. O pré-teste foi realizado com 25 instrumentos. A amostra para a análise de campo foi constituída por mais 25 instrumentais cirúrgicos. Os resultados obtidos permitiram a construção de um instrumento com 19 itens e a análise de campo constatou que houve diferenças nos escores das soluções avaliadas. O produto P5 obteve a melhor média 78,7 (DP 6,68 e mediana 80,2 e o produto P4 obteve o pior desempenho, média 56,2 (DP 7,09 e mediana 56,7, em um intervalo possível de 19 a 95. O instrumento de medida mostrou-se confiável ao estudo, apresentando valor do Alpha de Cronbach de 0,83.Se trata de un estudio de desarrollo metodológico que tuvo como objetivo construir un instrumento de evaluación de detergentes enzimáticos y analizar la acción de los productos sobre los instrumentales. El instrumento fue sometido al análisis de tres jueces. El pre test fue realizado con 25 instrumentos. La muestra para el análisis de campo estuvo constituida por más de 25 instrumentales quirúrgicos. Los resultados obtenidos permitieron la construcción de un instrumento con 19 items y por el análisis de campo se constató que hubo diferencias en los escores de las soluciones evaluadas. El producto P5 obtuvo el mejor pro-medio de 78,7 (DP 6,68 y mediana de 80,2 y el producto P4 obtuvo el peor desempeño, promedio de 56,2 (DP 7,09 y mediana de 56,7, en un intervalo posible de 19 a 95. El instrumento de medida se mostró confiable para el estudio, presentando valor del Alpha de Cronbach de 0,83.The objective of this study was to develop an instrument for measuring the quality of enzymatic detergents and analyze their cleaning action on surgical instruments. The instrument was submitted to a panel of three judges

  10. A fotografia de natureza como instrumento para educação ambiental Nature photography as an instrument in Environmental Education

    Directory of Open Access Journals (Sweden)

    Marilia Dammski Borges

    2010-01-01

    Full Text Available A visão é um dos sentidos mais importantes nos humanos e, por isso, a fotografia pode ser uma excelente opção para driblar a falta de recursos na educação ambiental, sensibilizando e ensinando por meio de sua informação e beleza. Partindo disso, este trabalho destina-se a estabelecer como a fotografia da natureza instrumentaliza a educação ambiental e contribui no aprendizado de alunos do Ensino Fundamental e Educação de Jovens e Adultos (EJA. Foram ministradas palestras em metade das turmas escolhidas utilizando fotografias e, em outra metade, sem este recurso. Para testar o aprendizado foram aplicados questionários avaliativos. Nas turmas onde foram utilizadas fotografias, houve aumento significativo nas respostas corretas. Analisando os resultados, concluiu-se que a fotografia da natureza pode ser utilizada com eficácia para diversas faixas etárias e diferentes níveis de ensino como instrumento para a educação ambientalVision is one of the most important senses in humans and because of this the photographs are an excellent option to improve the lack of resources in Environmental Education. Photographs are a way of sensitizing and teaching the information and beauty of its components. The present article wants to establish how photographs of nature can give support to Middle School and Youths and Adults Education (EJA. Using Nature photography, presentations were made to half of the groups. The other half did not use the photographic resources. In order to test their knowledge, evaluative questionnaires were applied. At the groups that the photographs were used, there were a higher number of correct answers. Analyzing the results, it is possible to conclude that Nature photography can efficiently be used with different ages and also different levels of students as an instrument in the Environmental Education.

  11. New instrumentation of reactor water level for PWR; Nueva Instrumentacion de nivel de agua del reactor para PWR

    Energy Technology Data Exchange (ETDEWEB)

    Kaercher, S.

    2005-07-01

    Today, many PWR reactors are equipped with a reactor water level instrumentation system based on different measurement methods. Due to obsolescence issues, FRAMATOME ANP started to develop and quality a new water level measurement system using heated und unheated thermocouple measurements. the measuring principle is based on the fact that the heat transfer in water is considerably higher than in steam. The electronic cabinet for signal processing is based on a proven technology already developed, qualified and installed by FRAMATOME ANP in several NPPs. It is equipped with and advanced temperature measuring transducer for acquisition and processing of thermocouple signals. (Author)

  12. 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)

  13. Pulsed spallation Neutron Sources

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, J.M. [Argonne National Lab., IL (United States)

    1994-12-31

    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.

  14. Metodología para conseguir la diversificación instrumental en alumnos-as de entre 5 y 7 años de edad

    Directory of Open Access Journals (Sweden)

    Sarralde, Aitor

    2000-05-01

    Full Text Available Ante el problema observado de la escasa o nula diversificación instrumental de los niños que asisten a clases de música, desde el curso 1991-92 nos planteamos en el Centro de Estudios Musicales Juan Antxieta las siguientes hipótesis:· El hecho de que los alumnos elijan predominantemente los mismos instrumentos (piano, violín, guitarra... puede ser debido a la falta de contacto con el resto de instrumentos, por lo que dándoles laoportunidad de "jugar" con ellos, esta concentración puede quedar subsanada.· Si dicho "juego" es guiado por profesores especialistas, la elección instrumental no solo se basará en los gustos sino también en las aptitudes y actitudes hacia él.Método: A los 5 años, los niños asistirán 1 hora semanal a Lenguaje Musical y otra a RotaciónInstrumental. Los alumnos se dividen en 3 grupos, cada uno de los cuales está acompañado siempre del mismo profesor-tutor (pianista, tomando contacto cada trimestre con una familia instrumental (cuerda, viento, diversos, con lo que se consigue que el alumno "haya rotado" a lo largo del curso por todos losinstrumentos que se imparten en el centro. Además, los alumnos siempre están en contacto con el instrumentario Orff. Al final de cada trimestre se realiza un informe donde se recogen tanto las preferencias del alumno como las opiniones de los profesores.Teniendo en cuenta el instrumento elegido, en el siguiente curso el niño comienza la asignatura de Aula Instrumental donde estará en clase con toda la familia del instrumento elegido. Periódicamente mantendrá contactos con los grupos no elegidos.Ya, al siguiente curso, mediante el mismo proceso evaluador del informe, el alumno elegirá instrumento individual y junto a la hora de Lenguaje Musical, el alumno asiste a una hora (compartida con otro alumno de instrumento individual.Conclusiones: Hemos conseguido que la elección instrumental venga dada por las preferencias y aptitudes del alumno y no por la obligación del

  15. Peak nasal inspiratory flow: uma possível ferramenta para a motricidade orofacial? Peak nasal inspiratory flow: a possible instrument in orofacial myology?

    Directory of Open Access Journals (Sweden)

    Andréa Rodrigues Motta

    2010-12-01

    Full Text Available Os fonoaudiólogos que atuam no campo da Motricidade Orofacial atendem com frequência, pacientes com obstrução nasal; entretanto, nem sempre o acesso ao profissional responsável pelo diagnóstico otorrinolaringológico é fácil. O Peak Nasal Inspiratory Flow é um instrumento barato, de fácil manuseio, amplamente citado na literatura internacional, que tem por objetivo avaliar a patência nasal. O objetivo do presente estudo foi realizar uma revisão da literatura acerca do Peak Nasal Inspiratory Flow, fornecendo subsídios para reflexões acerca de seu emprego nos distúrbios miofuncionais orofaciais e cervicais. Para tanto, foi realizada uma revisão da literatura nas bases de dados Medline, Cochrane Library, LILACS e SciELO empregando-se os descritores peak, inspiratory, nasal e flow. O Peak Nasal Inspiratory Flow mostrou-se uma técnica simples, barata, validada e com boa reprodutibilidade. Parece, portanto, tratar-se de um instrumento útil para avaliação da patência nasal, apesar de algumas limitações, fornecendo dados complementares ao diagnóstico miofuncional orofacial e cervical. Entretanto, estudos clínicos precisam ser conduzidos para que se comprove ou refute a hipótese.The speech-language pathologists that work in the Orofacial Myology field frequently have patients with nasal obstruction; however, the access to the professional responsible for the diagnosis can be difficult at times. The Peak Nasal Inspiratory Flow is a cheap and easy to handle instrument, broadly cited in the international literature, that has the aim to evaluate nasal patency. The aim of this study was to review the current literature regarding the Peak Nasal Inspiratory Flow, enabling considerations about its use in cervical and orofacial myology disorders. The literature review consulted Medline, Cochrane Library, LILACS and SciELO databases, using the keywords: peak, inspiratory, nasal and flow. The results showed that Peak Nasal Inspiratory Flow

  16. Evaluation of the environmental equivalent dose rate using area monitors for neutrons in clinical linear accelerators; Avaliacao da taxa de equivalente de dose ambiente utilizando monitores de area para neutrons em aceleradores lineares clinicos

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, Ana Paula; Pereira, Walsan Wagner; Patrao, Karla C. de Souza; Fonseca, Evaldo S. da, E-mail: asalgado@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Batista, Delano V.S. [Instituto Nacional do Cancer (INCa), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The Neutron Laboratory of the Radioprotection and Dosimetry Institute - IRD/CNEN, Rio de Janeiro, Brazil, initiated studies on the process of calibration of neutron area monitors and the results of the measurements performed at radiotherapy treatment rooms, containing clinical accelerators

  17. Generation of neutron cross sections library for the Thermos code of the Fuel management System (FMS); Generacion de la biblioteca de secciones eficaces de neutrones para el codigo Thermos del sistema de administracion de combustible (FMS)

    Energy Technology Data Exchange (ETDEWEB)

    Alonso V, G.; Viais J, J. [ININ, Gcia. Sistemas Nucleares, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1990-10-15

    There is developed a method to generate the library of neutron cross sections for the Thermos code by means of the database ENDF-B/IV and the NJOY code. The obtained results are compared with the version previous of the library of neutron cross sections which was processed using the version ENDF-B/III. (Author)

  18. Construção de instrumento para avaliar a acurácia diagnóstica Construcción de instrumento para evaluar la exactitud diagnóstica Development of an instrument to evaluate diagnosis accuracy

    Directory of Open Access Journals (Sweden)

    Fabiana Gonçalves de Oliveira Azevedo Matos

    2009-12-01

    Full Text Available Diagnósticos acurados são importantes para a escolha adequada de intervenções. Neste artigo relata-se pesquisa metodológica de desenvolvimento de instrumento para estimar a acurácia de diagnósticos de enfermagem a partir de dados escritos da avaliação de paciente. Elaborou-se a definição de acurácia e a construção dos itens que compõem o instrumento, submetendo-os a validação de conteúdo e teste piloto. O instrumento foi denominado Escala de Acurácia de Diagnóstico de Enfermagem - EADE e foi composto por 4 itens: Presença de pistas; Relevância da pista; Especificidade da pista e Coerência da pista. As respostas de 12 enfermeiros especialistas à aplicação da EADE aos diagnósticos de 5 casos escritos permitiram identificar valores para cada item e estimar a validade e confiabilidade da EADE.Diagnósticos precisos son importantes para la elección adecuada de las intervenciones. Este artículo se refiere al desarrollo de herramienta metodológica de investigación para estimar la precisión de los diagnósticos de enfermería apartir de datos escritos de la evaluación de paciente. Se elaboró la definición de la precisión y la construcción de los elementos que componen el instrumento, sometiéndolos a prueba del contenido y el test piloto. El instrumento fue llamado Exactitud Diagnóstica de Enfermería - EADE y estaba compuesto por 4 elementos: Presencia de pistas; Pertinencia de la pista; especificidad de la pista y la coherencia de la pista. Las respuestas de 12 enfermeros especialistas a la aplicación de EADE a los diagnósticos de 5 casos por escrito permitiran identificar los valores para cada tema y estimar la validez y la fiabilidad de EADE.Accurate diagnoses are important for choosing adequate interventions. This study reports on a methodological research that developed an instrument to estimate nursing diagnosis accuracy, based on written data from patients' assessment. A definition of accuracy was

  19. 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

  20. Comment on "Elastic incoherent neutron scattering operating by varying instrumental energy resolution: Principle, simulations, and experiments of the resolution elastic neutron scattering (RENS)" [Rev. Sci. Instrum. 82, 105115 (2011)].

    Science.gov (United States)

    Wuttke, Joachim

    2012-10-01

    In a recent contribution to this journal, Magazù, Migliardo, and Benedetto suggest to determine relaxation times from inflection points in the elastic neutron scattering intensity as function of (1) resolution time or (2) temperature. Method (1) can be generalized into a scaling law. Method (2) is only approximately valid; its application to protein data does not back a wavenumber-independent dynamic transition.

  1. Implementation of the k{sub 0}-standardization Method for an Instrumental Neutron Activation Analysis: Use-k{sub 0}-IAEA Software as a Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong Sam; Moon, Jong Hwa; Kim, Sun Ha; Kim, Hark Rho [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Ho, Manh Dung [Nuclear Research Institute, Dalat (Viet Nam)

    2006-03-15

    Under the RCA post-doctoral program, from May 2005 through February 2006, it was an opportunity to review the present work being carried out in the Neutron Activation Analysis Laboratory, HANARO Center, KAERI. The scope of this research included: a calibration of the counting system, a characterization of the irradiation facility ,a validation of the established k{sub o}-NAA procedure.The k{sub o}-standardization method for an Neutron Activation Analysis(k{sub o}-NAA), which is becoming increasingly popular and widespread,is an absolute calibration technique where the nuclear data are replaced by compound nuclear constants which are experimentally determined. The k{sub o}-IAEA software distributed by the IAEA in 2005 was used as a demonstration for this work. The NAA no. 3 irradiation hole in the HANARO research reactor and the gamma-ray spectrometers No. 1 and 5 in the NAA Laboratory were used.

  2. Instrumentos para avaliação da linguagem pós-lesão cerebrovascular esquerda Instruments for language assessment following a left brain damage

    Directory of Open Access Journals (Sweden)

    Karina Carlesso Pagliarin

    2013-04-01

    Full Text Available O tema deste estudo é a avaliação padronizada da linguagem em pacientes com lesão cerebrovascular esquerda (LHE que pode ser muito útil no estabelecimento do diagnóstico, prognóstico e plano terapêutico, complementando observação, entrevistas e tarefas clínicas. Este estudo teve como objetivo identificar quais instrumentos de investigação de linguagem têm sido utilizados para avaliação de quadros neurológicos súbitos envolvendo o hemisfério esquerdo (HE e analisar quais componentes linguísticos são os mais avaliados. Foi possível identificar nove instrumentos utilizados internacionalmente que avaliam diferentes componentes linguísticos em pacientes com LHE; no contexto nacional, porém, foram encontradas apenas duas baterias para avaliação dessa população, ficando evidente a necessidade da construção e/ou de adaptação de instrumentos para a população brasileira. Os componentes linguísticos mais investigados foram nomeação e compreensão oral, respectivamente. A avaliação da linguagem torna-se essencial nos quadros envolvendo o HE, pois déficits linguísticos podem acarretar prejuízos sociais, ocupacionais e familiares.The theme of this study is the language assessment in patients with left brain damage (LBD. It is necessary as it helps to establish the diagnosis, prognosis and rehabilitation planning, adding findings to clinical observation, interview and tasks. The purpose is to identify which language instruments have been used to assess non-progressive neurological disorders involving the left hemisphere (LH and to analyze which language components are the most assessed ones. It was possible to identify nine international instruments that assess different components of language in LBD patients. In the national context, however, only two batteries to assess this population were found, highlighting the need for construction and/or adaptation of language assessment tools for the Brazilian population

  3. Characterization of the neutron field of the {sup 241}AmBe in a calibration room; Caracterizacion del campo de neutrones del {sup 241} AmBe en una sala para calibracion

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H.R. [UAZ, A.P. 336, 98000 Zacatecas (Mexico); Gallego, E.; Lorente, A. [Universidad Politecnica de Madrid, C. Jose Gutierrez Abascal 2, 28006 Madrid (Spain)] e-mail: rvega@cantera.reduaz.mx

    2003-07-01

    The field of neutrons produced by an isotopic source of neutrons of {sup 241} Am Be had been characterized. The characterization was carried out modeling those relevant details of the calibration room and simulating the neutron transport at different distances of the source. The calculated spectra were used to determine the equivalent environmental dose rate. A series of experiments were carried out with the Bonner sphere spectrometric system to measure the spectra in the same points where the calculations were carried out and with these spectra the rates of environmental dose were calculated. By means of a one sphere dosemeter type Berthold the rates of environmental dose were measured. To the one to compare the calculated spectra and measured its were found small differences in the group of the thermal neutrons due to the elementary composition used during the simulation. When comparing the derived rates starting from the calculated spectra with those measured it was found a maxim difference smaller to 13%. (Author)

  4. Development of the P{sub N} method for plane geometry neutron slowing down studies; Desenvolvimento do metodo P{sub N} para estudo da moderacao de neutrons em geometria plana

    Energy Technology Data Exchange (ETDEWEB)

    Caldeira, A.D.; Dias, A.F.; Garcia, R.D.M. [Centro Tecnico Aeroespacial (CTA-IEAv), Sao Jose dos Campos, SP (Brazil). Inst. de Estudos Avancados

    1997-12-01

    A new version of the P{sub N} method for solving the two-group neutron transport equation in plane geometry without up scattering is reported. Contrasting with the conventional matrix approach, the developed version is based on a group-by-group solution of the transport equation which makes it specially well-suited for neutrons slowing-down calculations. (author). 14 refs., 2 tabs.

  5. General Design for CARR Neutron Guide System

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A neutron guide system has been designed and partly installed at the China Advanced Research Reactor (CARR) to transport cold neutrons from the cold neutron source (CNS) to several instruments,which are situated in a separate guide hall of 30 m×60 m.

  6. Development of neutron optical components at ILL

    CERN Document Server

    Courtois, P; Humblot, H; Alianelli, L; Pfeiffer, F O

    2002-01-01

    The neutron optics laboratory at ILL carries out an innovative research program in various fields of neutron optics with the aim of developing new and improved tools for neutron instrumentation. An overview of some recent highlights is presented, indicating the breadth of the potential applications. (orig.)

  7. Low dimensional neutron moderators for enhanced source brightness

    DEFF Research Database (Denmark)

    Mezei, Ferenc; Zanini, Luca; Takibayev, Alan;

    2014-01-01

    In a recent numerical optimization study we have found that liquid para-hydrogen coupled cold neutron moderators deliver 3–5 times higher cold neutron brightness at a spallation neutron source if they take the form of a flat, quasi 2-dimensional disc, in contrast to the conventional more voluminous...... for cold neutrons. This model leads to the conclusions that the optimal shape for high brightness para-hydrogen neutron moderators is the quasi 1-dimensional tube and these low dimensional moderators can also deliver much enhanced cold neutron brightness in fission reactor neutron sources, compared...

  8. Development of a system for passive spectrometry characterization neutron of a cyclotron; Desarrollo de un sistema de espectrometria pasivo para la caracterizacion neutronica de un ciclotron

    Energy Technology Data Exchange (ETDEWEB)

    Mendez, R.; Guerrero, J. E.; Lagares, J. I.; Sansaloni, F.; Perez, J. M.; Llop, J.; Kralik, M.

    2013-07-01

    The most widely used for Neutron spectrometry system is formed by the Bonner spheres with an active sensor sensitive to thermal neutrons in its Center. But, the presence of strong electromagnetic fields and the hold character around a cyclotron radiation detectors active employment make unviable so it is necessary to replace it with other liabilities. In this case it has resorted to the use of Au foils such as thermal neutron detectors, found the matrix the new spectrometer response and has been validated with a source of {sup 2}52Cf for later measurements in the interior of the bunker of a cyclotron production of radioisotopes for PET. (Author)

  9. Simulator of the NUMAC SRMN module as virtual instrument for the personnel training of the LVNP; Simulador del modulo NUMAC SRMN como instrumento virtual para el adiestramiento del personal de CNLV

    Energy Technology Data Exchange (ETDEWEB)

    Rojas S, A.S.; Rivero G, T.; Ruiz E, J.A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: asrs@nuclear.inin.mx

    2006-07-01

    Inside the training programs of the personnel's of the Laguna Verde Nuclear power station (CNLV) Veracruz, Mexico, is necessary to carry out practices with instruments or electronic equipment contained inside the reactor instrumentation, most of these equipment are in operation and its can be part important of the safety system of the reactor, for what is sometimes impossible to carry out or to modify its operation conditions. The nuclear industry always has offered the improvement of the systems and equipment that compose the nuclear power station. In this context, during the last years, they have been carried out diverse upgrades of the systems in the CNLV, among them they are the dedicated measurement equipment and nuclear control (NUMAC, by its initials in English). It would be desirable to have a support tool that allows the interactive knowledge of these systems elevating by this way the quality of the personnel's preparation. In this work the NUMAC system by means of a virtual instrument, which has the facilities of developing practices and programs of training is presented. The NUMAC (Nuclear Measurement Analysis and Control), its are controllers connected to the SIIP (Integral System of Process Information), of the following types: RWM (Rod Worth Minimizer), LDM (Leak Detection Monitor), ATCU (Automatic TIP Control Unit [TIP: Traversing In-Core Probe]), LCR (Log Count Rate), LRM (Logarithmic Radiation Monitor), PRNM Power Range Neutron Monitor, SRNM (Start-up Range Neutron Monitor). The NUMAC, are instruments for monitoring and control of the reactor whose introduction is relatively recent, these instruments are connected to the SIIP, its are microprocessors similar to the industrial computers, dedicated to measure and to control systems in the plant. By safety, the control is programmed and it is configured locally in each processor and in the workstations of the SIIP, only the acquired information of these devices is presented. This work

  10. NEUTRON IMAGING, RADIOGRAPHY AND TOMOGRAPHY.

    Energy Technology Data Exchange (ETDEWEB)

    SMITH,G.C.

    2002-03-01

    Neutrons are an invaluable probe in a wide range of scientific, medical and commercial endeavors. Many of these applications require the recording of an image of the neutron signal, either in one-dimension or in two-dimensions. We summarize the reactions of neutrons with the most important elements that are used for their detection. A description is then given of the major techniques used in neutron imaging, with emphasis on the detection media and position readout principle. Important characteristics such as position resolution, linearity, counting rate capability and sensitivity to gamma-background are discussed. Finally, the application of a subset of these instruments in radiology and tomography is described.

  11. Polarized neutron scattering on HYSPEC: the HYbrid SPECtrometer at SNS

    Energy Technology Data Exchange (ETDEWEB)

    Zaliznyak, Igor [Brookhaven National Laboratory (BNL); Savici, Andrei T [ORNL; Garlea, Vasile O [ORNL; Winn, Barry L [ORNL; Schneelock, John [Brookhaven National Laboratory (BNL); Tranquada, John M. [Brookhaven National Laboratory (BNL); Gu, G. D. [Brookhaven National Laboratory (BNL); Wang, Aifeng [Brookhaven National Laboratory (BNL); Petrovic, C [Brookhaven National Laboratory (BNL)

    2017-01-01

    We describe some of the first polarized neutron scattering measurements performed at HYSPEC spectrometer at the Spallation Neutron Source, Oak Ridge National Laboratory. We discuss details of the instrument setup and the experimental procedures in the mode with the full polarization analysis. Examples of the polarized neutron diffraction and the polarized inelastic neutron data obtained on single crystal samples are presented.

  12. Estudo anatômico da cóclea para confecção de instrumental para a cirurgia de implante coclear com 2 feixes de eletrodos em cócleas ossificadas Cochlear anatomy study used to design surgical instruments for cochlear implants with two bundles of electrodes in ossified cochleas

    Directory of Open Access Journals (Sweden)

    Mariana Bogar

    2008-04-01

    Full Text Available A ossificação da cóclea, decorrente principalmente de meningite, impede a inserção completa do implante coclear convencional. Os implantes com 2 feixes de eletrodos mais curtos do que o convencional foram desenvolvidos especialmente para cócleas ossificadas. Porém, durante essa cirurgia há um grande risco de lesão da artéria carótida interna (ACI. Portanto, a medida da profundidade das cocleostomias para inserir os dois feixes de eletrodos aumentaria a segurança desse procedimento. OBJETIVOS: 1 Obter as distâncias entre as cocleostomias e a ACI em ossos temporais de cadáver; 2 Confeccionar instrumento que possa ser usado na cirurgia de implante coclear com 2 feixes de eletrodos. FORMA DE ESTUDO: Experimental prospectivo. MATERIAL E MÉTODO: Em 21 ossos de cadáveres foi realizada: 1 mastoidectomia cavidade aberta; 2 cocleostomias nos giros basal e médio da cóclea; 3 identificação da ACI; 4 medida da distância entre as cocleostomias e a artéria. RESULTADOS: A medida média ± desvio padrão obtida para o túnel superior foi 8,2 ± 1,1mm e para o túnel inferior foi 8,1± 1,3mm. A menor distância encontrada foi 6,5mm para o túnel superior e 6,0mm para o túnel inferior. CONCLUSÃO: Apesar dos parâmetros calculados concluímos que a melhor medida para ser considerada na confecção do instrumento cirúrgico serão as mínimas medidas obtidas em cada um dos giros cocleares, pois é a maneira mais segura para evitar a lesão da ACI, que pode ser fatal.Cochlear ossification, mainly secondary to meningitis, prevents the complete conventional cochlear implant insertion. Implants with two electrode bundles shorter than the conventional ones were specifically developed for ossified cochleas. However, during surgery there is a high risk of damaging the internal carotid artery (ICA. Therefore, measuring cochleostomy depth in order to insert the two electrode bundles would greatly increase the procedure's safety. AIMS: 1 Find the

  13. DESARROLLO DE UN INSTRUMENTO PARA EVALUAR PRERREQUISITOS EN EL SISTEMA HACCP DESENVOLVIMENTO DE UM INSTRUMENTO PARA AVALIAR PRÉ-REQUISITOS NO SISTEMA HACCP DEVELOPMENT OF AN INSTRUMENT TO EVALUATE PREREQUISITES TO HACCP SYSTEM

    Directory of Open Access Journals (Sweden)

    NELSON GUTIÉRREZ

    2010-06-01

    Full Text Available En este artículo se presenta la construcción y validación inicial del instrumento GHYCAL (Gestión de la Higiene y Calidad, aplicable en el diagnóstico de los 7 planes previos de higiene y trazabilidad, necesarios para implantar un protocolo Análisis de Peligros y Puntos Críticos de Control (HACCP en cualquier empresa del sector agroalimentario. Para su construcción se elaboró un primer instrumento que contenía 78 criterios relacionados con gestión de la higiene en la industria agroalimentaria, que fue sometido a un proceso de validación de contenido por expertos conocedores de temas relacionados con inocuidad, seguridad alimentaria e higiene de alimentos, utilizando la metodología conocida como sesiones Delphi; posteriormente, se realizó el cálculo de confiabilidad utilizando como medida de consistencia interna el coeficiente Alfa de Cronbach, mediante la aplicación del instrumento en 53 empresas del sector agroalimentario; por último, se determinó la validez de criterio, comparando los resultados de aplicación del instrumento GHYCAL con los resultados de aplicación del instrumento Safety and Quality on Food (S&Q, en las mismas 53 empresas del sector agroalimentario. El instrumento final compuesto por 77 ítems contenidos en 7 sets de preguntas que corresponden a los mismos prerrequisitos establecidos en el protocolo HACCP, obtuvo valores de alfa de Cronbach entre 0,83 y 0,94 para los sets de preguntas y de 0,98 para el total del cuestionario, con respecto a la evidencia relacionada con el criterio, los resultados similares permiten adoptar el concepto de validez concurrente.Neste artigo se apresenta a construção e validação inicial do instrumento GHYCAL (Gestão da Higiene e Qualidade; aplicável no diagnóstico dos 7 planos prévios de higiene e rastreabilidade, necessários para implantar um protocolo de Análise de Perigos e Pontos Críticos de Controle (HACCP em qualquer empresa do setor agroalimentício. Para a sua

  14. El defensor de la audiencia como instrumento para la educación en medios The newsombudsman as an instrument for media education

    Directory of Open Access Journals (Sweden)

    Susana Herrera Damas

    2008-03-01

    Full Text Available Ya casi nadie lo duda. A pesar de que vivimos en la denominada «sociedad de la información », muchas veces los sistemas tradicionales no capacitan a la audiencia para que realice un consumo crítico de los medios. Por eso, los espacios tradicionales deben ser completados por la intervención de otros actores. Uno de ellos es el defensor de la audiencia. El objetivo de este artículo es describir la singularidad de este mecanismo y especificar los instrumentos de los que dispone en su tarea formativa. Everybody agrees. Although we lived in the so-called Information Society, traditional systems do not enable people to make a critical consumption of mass media. For that reason, the traditional spaces must be completed by the intervention of other actors. One of them is the newsombudsman. The aim of this article is to describe the singularity of this mechanism and to specify his instruments in his educational task.

  15. The platinum group elements and gold: analysis by radiochemical and instrumental neutron activation analysis and relevance to geological exploration and related problems

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, S.; Plimer, I. R. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    This paper presents an overview of research conducted with the support of the Australian Institute of Nuclear Science and Engineering, at the University of Melbourne, School of Earth Sciences, Radiochemical Neutron Activation Laboratory. The primary objective of this research is to realize the high potential of the platinum group elements (PGE) and gold to the solution of petrogenetic problems, the study of magma generation and magmatic processes in mafic/ultramafic rock suites, as tracers in hydrothermal ore formation. The PGEs (Os, Ru, Ir, Pt, Pd and Rh) are among the least abundant of all elements on earth with unique properties such as high melting points, high electrical and thermal conductivity, high density, strength and toughness as alloys. They exhibit both siderophile and chalcophile characteristics and are valuable tools in providing information about magmatic processes, in particular S-saturation, as well as crystal fractionation trends. Two distinct groups of PGEs are discerned; the IPGEs (Ru, Os, Ir) and the PPGEs (Pt, Pd, Rh, Au) on the basis of their behaviour during fractionation processes. Using chondrite normalized PGE patterns it is possible to distinguish between sulphides that segregated from primitive magmas, such as komatiites, and sulphides which segregated from more fractionated magmas, such as tholeiites. It is critical to the understanding of these processes to be able to analyse key elements, such as the PGE and gold, in the parts per billion to parts per trillion range. Platinum group elements and Au were determined by radiochemical neutron activation analysis using a modified NiS fire-assay preconcentration technique, adapted from procedures first used by Robert, R.V. D. and van Wyk, E. (1975) . Detection limits are generally 0.005-0.01 ppb (Au and Ir), 0.1-0.2 ppb (Pd and Pt), and 0.1-0.5 ppb for Ru. 9 refs.

  16. The LTS{sub N} method used for the determination of parameters in heterogeneous shielding for neutrons and photons; O uso do metodo LTS{sub N} na obtencao de parametros de blindagens multiplas para neutrons e fotons

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Volnei [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Dept. de Engenharia Nuclear; Francio, Laci Maria; Brigoni, Justina Ines Fronza [Universidade de Caxias do Sul, RS (Brazil). Dept. de Ciencias Exatas e da Natureza

    2002-07-01

    In this work the LTS{sub N} methodology is used for determination of the radiation flux distribution into the homogeneous and heterogeneous shielding, using the multigroup model in energy, for photons and neutrons. Numerical results for emergent flux, absorbed dose rates and buildup factor are reported. (author)

  17. Generation of the library of neutron cross sections for the Record code of the Fuel Management System (FMS); Generacion de la biblioteca de secciones eficaces de neutrones para el codigo Record del Sistema de Administracion de Combustible (FMS)

    Energy Technology Data Exchange (ETDEWEB)

    Alonso V, G.; Hernandez L, H. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1991-11-15

    On the basis of the library structure of the RECORD code a method to generate the neutron cross sections by means of the ENDF-B/IV database and the NJOY code has been developed. The obtained cross sections are compared with those of the current library which was processed using the ENDF-B/III version. (Author)

  18. Determination of the Elemental Composition of the Pulp, Seed and Fruit Coat of Black Velvet Tamarind (Dialium guineense using Instrumental Neutron Activation Analysis

    Directory of Open Access Journals (Sweden)

    D.O. Ofosu

    2013-10-01

    Full Text Available This study sought to provide data on the mineral composition of the fruit pulp, outer coat and seed of Dialiu guineense in an attempt to widen the sources of minerals for the rural population of sub-Saharan Africa. The elemental composition of the pulp, seed and fruit coat of black velvet tamarind (Dialiu guineense was determined using Neutron Activation Analysis. The fruit pulp contained manganese (23.40±1.57µg/g, chlorine (205.40±37.59 &mu g/g, calcium (5671.00±2132.30 &mug/g, sodium (332.95±8.76 &mud/gand potassium (6190.00±711.85 &mug/g. The seed and fruit coat contained all these minerals except potassium and sodium respectively. The fruit pulp can serve as a good source of macrominerals for humans while the fruit coat and seed could be ground and incorporated in various meal formulations of livestock as mineral supplements.

  19. Neutron Repulsion

    OpenAIRE

    Manuel, Oliver K.

    2011-01-01

    Earth is connected gravitationally, magnetically and electrically to its heat source - a neutron star that is obscured from view by waste products in the photosphere. Neutron repulsion is like the hot filament in an incandescent light bulb. Excited neutrons are emitted from the solar core and decay into hydrogen that glows in the photosphere like a frosted light bulb. Neutron repulsion was recognized in nuclear rest mass data in 2000 as the overlooked source of energy, the keystone of an arch...

  20. Consciência metatextual: evidências de validade para instrumento de medida Consciencia metatextual: evidencias de validez para instrumento de medida Metatextual awareness: evidence of validity for measuring instrument

    Directory of Open Access Journals (Sweden)

    Acácia Aparecida Angeli dos Santos

    2012-08-01

    Full Text Available O objetivo estabelecido nesta pesquisa descritivo-correlacional foi a averiguação da consciência metatextual por meio de um questionário especialmente elaborado para este fim, analisando sua validade pela relação com medidas de compreensão de leitura e o critério de diferenciação do nível escolar. Participaram 315 alunos do 3º ao 5º ano do ensino fundamental, de escolas públicas, cujas idades variaram de 8 a 13 anos, sendo 169 meninos. Os escores obtidos com a medida de avaliação da consciência metatextual (QACM foram convergentes com a pontuação em compreensão de leitura e o instrumento mostrou-se sensível para captar o progresso das crianças em identificar os gêneros textuais com o avanço da escolaridade. Dessa forma, o estudo forneceu evidências de validade tanto no que se refere à convergência de construtos, identificada com base nas medidas relacionadas, como de critério, distinguindo os alunos pelo seu nível de escolaridade.El objetivo establecido en esta investigación descriptivo-correlacional fue averiguar la consciencia metatextual a través de un cuestionario especialmente diseñado para este fin, analizando su validez por la relación con medidas de comprensión de lectura y el criterio de diferenciación por nivel escolar. Participaron 315 alumnos del 3º al 5º año de la enseñanza básica, de escuelas públicas, cuyas edades variaron de 8 a 13 años, siendo 169 niños. Los puntajes obtenidos con la medida de evaluación de la consciencia metatextual (QACM fueron convergentes con los de la comprensión de lectura y el instrumento se mostró sensible para captar el desarrollo de los niños en identificar los géneros textuales con el avance de la escolaridad. De esa forma, el estudio forneció evidencias de validez por la convergencia de constructos, identificada con base en las medidas relacionadas, como de criterio, distinguiendo los alumnos por su nivel de escolaridad.The stated goal of this

  1. Comparação de métodos para determinação da maciez instrumental e do comprimento do sarcômero de carne bovina

    OpenAIRE

    2016-01-01

    Pelas características da pecuária e das indústrias frigoríficas brasileiras, não é incomum nos depararmos com consumidores insatisfeitos em relação qualidade da carne, principalmente a maciez, que muitas vezes pode estar ligada ao grau de encolhimento dos sarcômeros. Objetivou-se comparar duas técnicas para determinação do comprimento de sarcômero, microscopia de contraste de fases (Sarcm) e difração de raio laser (Sarcl), e de dois protocolos para avaliação da maciez instrumental, Warner-Bra...

  2. Neutron imaging of radioactive sources

    Science.gov (United States)

    Hameed, F.; Karimzadeh, S.; Zawisky, M.

    2008-08-01

    Isotopic neutron sources have been available for more than six decades. At the Atomic Institute in Vienna, operating a 250 kW TRIGA reactor, different neutron sources are in use for instrument calibration and fast neutron applications but we have only little information about their construction and densities. The knowledge of source design is essential for a complete MCNP5 modeling of the experiments. Neutron radiography (NR) and neutron tomography (NT) are the best choices for the non-destructive inspection of the source geometry and homogeneity. From the transmission analysis we gain information about the shielding components and the densities of the radio-isotopes in the cores. Three neutron sources, based on (alpha, n) reaction, have been investigated, two 239PuBe sources and one 241AmBe source. In the NR images the internal structure was clearly revealed using high-resolving scintillation and imaging plate detectors. In one source tablet a crack was detected which causes asymmetric neutron emission. The tomography inspection of strong absorbing materials is more challenging due to the low beam intensity of 1.3x105 n/cm2s at our NT instrument, and due to the beam hardening effect which requires an extension of reconstruction software. The tomographic inspection of a PuBe neutron source and appropriate measures for background and beam hardening correction are presented.

  3. Comparative analysis between P1 and B1 equations for neutron moderation; Analise comparativa entre os metodos de obtencao e das solucoes das equacoes P1 e B1 para moderacao de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Aquilino Senra; Silva, Fernando Carvalho da; Cardoso, Carlos Eduardo Santos [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear

    2000-07-01

    In order to calculate the neutron flux in nuclear reactors, B1 or P1 equations are solved by numerical methods for several groups of energy. The neutron fluxes obtained from the solutions of the B1 and P1 equations are similar when they are applied to large nuclear power reactors. However, an important difference between the two fluxes is that the system of P1 equations uses one more approximation than the B1 system and then, its flux is less precise. The present work shows the relations between both equations and analyzes for what conditions the two equations systems are equivalent. Furthermore, this equations are numerically solved in 54 groups of energy for a quadrangular arrange. (author)

  4. Solution of the neutron diffusion equation to study the 3D distribution of power, applied to nuclear reactors; Solucao da equacao de difusao de neutrons para o estudo da distribuicao de potencia em 3D, aplicado a reatores nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Danilo Leite

    2013-07-01

    This work aims to present a study about the power distribution behavior in a PWR type reactor, considering both intensity and migration of power peaks due to insertion of control rods into the core. Employing the multidimensional steady-state neutron diffusion equation in order to simulate the neutron flux, and using the Finite Difference Method. Furthermore, based on the axial power distribution on the largest heat flux rod, is carried out thermal analysis of this rod and associated coolant channel. For this purpose is employed the FueLRod{sub 3}D code, it uses the Finite Element Method to model the fuel rod and the associated coolant channel, allowing the thermohydraulics simulation of a single rod discretized in three dimensions, considering the heat flux from the pellet, crossing the gap and the cladding until it reaches the coolant. (author)

  5. Development of a tissue equivalent proportional counter for separation of neutron-gamma mixed field; Desenvolvimento de um contador proporcional equivalente-tecido para separacao de campos mistos neutron-gama

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Abel Antonio da

    1991-01-01

    The construction and development of a proportional counter sensitive to neutrons and gamma rays, which permits to simulate a microscopic region of tissue in order of some microns, is proposed. A spectral distribution in energy from the radiations is obtained from this counter, which treated adequately permits the computation of the absorved dose, dose equivalent and quality factor in a alarge range of energy. (author). 18 refs., 31 figs., 18 tabs.

  6. Design of a computation tool for neutron spectrometry and dosimetry through evolutionary neural networks; Diseno de una herramienta de computo para la espectrometria y dosimetria de neutrones por medio de redes neuronales evolutivas

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz R, J. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Ingenieria Electrica, Av. Ramon Lopez Velarde No. 801, Col. Centro, Zacatecas (Mexico); Martinez B, M. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Av. Ramon Lopez Velarde No. 801, Col. Centro, Zacatecas (Mexico); Gallego, E. [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, Jose Gutierrez Abascal No. 2, E-28006 Madrid (Spain)], e-mail: morvymmyahoo@com.mx

    2009-10-15

    The neutron dosimetry is one of the most complicated tasks of radiation protection, due to it is a complex technique and highly dependent of neutron energy. One of the first devices used to perform neutron spectrometry is the system known as spectrometric system of Bonner spheres, that continuous being one of spectrometers most commonly used. This system has disadvantages such as: the components weight, the low resolution of spectrum, long and drawn out procedure for the spectra reconstruction, which require an expert user in system management, the need of use a reconstruction code as BUNKIE, SAND, etc., which are based on an iterative reconstruction algorithm and whose greatest inconvenience is that for the spectrum reconstruction, are needed to provide to system and initial spectrum as close as possible to the desired spectrum get. Consequently, researchers have mentioned the need to developed alternative measurement techniques to improve existing monitoring systems for workers. Among these alternative techniques have been reported several reconstruction procedures based on artificial intelligence techniques such as genetic algorithms, artificial neural networks and hybrid systems of evolutionary artificial neural networks using genetic algorithms. However, the use of these techniques in the nuclear science area is not free of problems, so it has been suggested that more research is conducted in such a way as to solve these disadvantages. Because they are emerging technologies, there are no tools for the results analysis, so in this paper we present first the design of a computation tool that allow to analyze the neutron spectra and equivalent doses, obtained through the hybrid technology of neural networks and genetic algorithms. This tool provides an user graphical environment, friendly, intuitive and easy of operate. The speed of program operation is high, executing the analysis in a few seconds, so it may storage and or print the obtained information for

  7. Characteristics of the quarry as shielding for {sup 241}AmBe neutrons and monoenergetic photons; Caracteristicas de la cantera como blindaje para los neutrones del {sup 241}AmBe y fotones monoenergeticos

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H. R.; Hernandez D, V. M.; Letechipia de L, C.; Salas L, M. A. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico); Rodriguez R, J. A.; Juarez A, C. A., E-mail: fermineutron@yahoo.com [Universidad Autonoma de Nuevo Leon, Facultad de Ingenieria Civil, Pedro de Alba s/n, San Nicolas de los Garza, Nuevo Leon (Mexico)

    2016-09-15

    Shielding is an important element in radiation protection since allows the management of radiation sources. Currently there are different materials of natural or anthropogenic origin that are used as shielding for both photons and neutrons. The quarry is a material of natural origin and abundant in our country, which is used in construction or for the manufacture of sculptures, however its characteristics as shielding have not been reported. In this paper we report some of the properties of the quarry as shielding for monoenergetic photons and for neutrons produced by an isotopic neutron source of {sup 241}AmBe. A quarry piece was used to determine its density and its chemical composition, with the XCOM code the elemental composition was determined and the mass interaction and total attenuation coefficients of the quarry were determined with photons of 10{sup -3} to 10{sup -5} MeV; the interaction coefficients included coherent dispersion, photoelectric absorption, Compton dispersion and the production of pairs in the nuclear and electronic field. Using the MCNP5 code, a narrow geometry attenuation experiment was modeled and the photon fluence was estimated that reaches a point detector at a distance of 42 cm from a point source, isotropic and monoenergetic photon when the source and the point detector were added quarry pieces of different thicknesses. The reduction of the number of photons as a function of the thickness of the quarry was used to determine the coefficient of linear attenuation of the quarry before photons of 0.03, 0.07, 0.1, 0.3, 1, 2 and 3 MeV that were the same as those calculated with the XCOM code. With the MCNP, the K a and H(10) transmission curves were also calculated. This same model was used to determined the variation of the {sup 241}AmBe neutron spectrum as a function of quarry thickness, as well as the E{sub ROT} and H(10) transmission curves. (Author)

  8. 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)

  9. 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)

  10. Quality assessment of neutron delivery system for small-angle neutron scattering diffractometers of the Jülich Centre for Neutron Science at the FRM II

    Science.gov (United States)

    Radulescu, Aurel; Pipich, Vitaliy; Ioffe, Alexander

    2012-10-01

    Following the shutdown of FRJ-2 research reactor in Jülich, the pinhole small-angle neutron diffractometers KWS-1 and KWS-2 have been moved to the research reactor FRM II in Garching. The installation of these 40 m long instruments required the design and setup of new neutron guides with geometrical and optical features imposed by the instruments' positioning in the neutron guide hall, such as, the predetermined length and beam height as well as the foreseen improvement of the instrument performance. We report here about the quality assessment of the newly constructed neutron guides with respect to the optical, geometrical and alignment characteristics and the positioning of the velocity selector integrated in the neutron guide system by comparing the features of the measured neutron beams (in terms of neutron flux, intensity distribution and beam profile) with the results of the simulations of optimal neutron guide systems.

  11. Optimization of artificial neural networks for the reconstruction of the neutrons spectrum and their equivalent doses; Optimizacion de redes neuronales artificiales para la reconstruccion del espectro de neutrones y sus dosis equivalentes

    Energy Technology Data Exchange (ETDEWEB)

    Reyes A, A.; Ortiz R, J. M.; Reyes H, A.; Castaneda M, R.; Solis S, L. O.; Vega C, H. R., E-mail: art8291@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Ingenieria Electrica, Av. Lopez Velarde No. 801, Col. Centro, 98000 Zacatecas (Mexico)

    2014-08-15

    In this work was used the robust design methodology of artificial neural networks to determine a good topology of net able to solve with efficiency the problems of neutrons spectrometry and dosimetry. For the design of the topology of optimized net 36 different net architectures based on an orthogonal arrangement with a configuration L{sub 9}(3{sup 4}), L{sub 4}(3{sup 2}) were trained. For the training of the neural networks, was used a computer code developed in the ambient of Mat lab programming, which automates the process and analysis of the information, reducing the time used in this activity considerably for the investigator. For the training of the propagation nets forward was utilized a neutrons spectrum compendium published by the International Atomic Energy Agency, where of the total 80% was used for the training and 20% for the test, it trained with an inverse propagation algorithm being the entrance data the count rates corresponding to the 7 spheres of the spectrometric system of Bonner spheres, as exit data, the neural network obtains the neutrons spectrum expressed in 60 energy groups and are calculated of simultaneous way 15 dosimetric quantities. (Author)

  12. Introduction to neutron scattering. Lecture notes of the introductory course

    Energy Technology Data Exchange (ETDEWEB)

    Furrer, A. [ed.

    1996-12-31

    These proceedings enclose ten papers presented at the 1. European Conference on Neutron scattering (ECNS `96). The aim of the Introductory Course was fourfold: - to learn the basic principles of neutron scattering, - to get introduced into the most important classes of neutron scattering instruments, -to learn concepts and their transformation into neutron scattering experiments in various fields of condensed matter research, - to recognize the limitations of the neutron scattering technique as well as to the complementarity of other methods. figs., tabs., refs.

  13. Characterization and use of shadow cone in a calibration laboratory for neutron; Caracterizacion y empleo de conos de sombra en un laboratorio para calibracion neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Gallego Diaz, E.; Valle Diez, A. del; Lorente Fillol, A.; Vega Carrillo, H. R.

    2011-07-01

    We present the design, characterization and use of shadow cones neutron measurements of the Laboratory of Nuclear Engineering Department of the ETSII-UPM (LMN-UPM), with an irradiation room size 9 mx 16 mx 8 m in that used an {sup 2}41Am-Be source of 11 GBq (3 Ci).

  14. HADES. A computer code for fast neutron cross section from the Optical Model; HADES. Un programa numerico para el calculo de seccciones eficaces neutronicas mediante el modelo optico

    Energy Technology Data Exchange (ETDEWEB)

    Guasp, J.; Navarro, C.

    1973-07-01

    A FORTRAN V computer code for UNIVAC 1108/6 using a local Optical Model with spin-orbit interaction is described. The code calculates fast neutron cross sections, angular distribution, and Legendre moments for heavy and intermediate spherical nuclei. It allows for the possibility of automatic variation of potential parameters for experimental data fitting. (Author) 55 refs.

  15. MeV Neutron Production from Thermal Neutron Capture in {6}^Li Simulated with Geant4

    CERN Document Server

    Santoro, Valentina; Bentley, Phillip M

    2015-01-01

    Various Li compounds are commonly used at neutron facilities as neutron absorbers. These compounds provide one of the highest ratios of neutron attenuation to $\\gamma$-ray production. Unfortunately, the usage of these compounds can also give rise to fast neutron emission with energies up to almost 16 MeV. Historically, some details in this fast neutron production mechanism can be absent from some modeling packages under some optimization scenarios. In this work, we tested Geant4 to assess the performance of this simulation toolkit for the fast neutron generation mechanism. We compare the results of simulations performed with Geant4 to available measurements. The outcome of our study shows that results of the Geant4 simulations are in good agreement with the available measurements for $^6$Li fast neutron production, and suitable for neutron instrument background evaluation at spallation neutron sources.

  16. MeV Neutron Production from Thermal Neutron Capture in 6Li Simulated With Geant4

    Science.gov (United States)

    Santoro, Valentina; DiJulio, Douglas D.; Bentley, Phillip M.

    2016-09-01

    Various Li compounds are commonly used at neutron facilities as neutron absorbers. These compounds provide one of the highest ratios of neutron attenuation to y- ray production. Unfortunately, the usage of these compounds can also give rise to fast neutron emission with energies up to almost 16 MeV. Historically, some details in this fast neutron production mechanism can be absent from some modeling packages under some optimization scenarios. In this work, we tested Geant4 to assess the performance of this simulation toolkit for the fast neutron generation mechanism. We compare the results of simulations performed with Geant4 to available measurements. The outcome of our study shows that results of the Geant4 simulations are in good agreement with the available measurements for 6 Li fast neutron production, and suitable for neutron instrument background evaluation at spallation neutron sources.

  17. 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...... on physics and data rather than the overwhelming instrumentation. We argue that this is because they can transfer their virtual experimental experience to the real-life situation. However, we also find that learning is still situated in the sense that only knowledge of particular experiments is transferred...

  18. 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...... on physics and data rather than the overwhelming instrumentation. We argue that this is because they can transfer their virtual experimental experience to the real-life situation. However, we also find that learning is still situated in the sense that only knowledge of particular experiments is transferred...

  19. Incapacidade funcional para atividades básicas e instrumentais da vida diária em idosos Disability relating to basic and instrumental activities of daily living among elderly subjects

    Directory of Open Access Journals (Sweden)

    Giovâni Firpo Del Duca

    2009-10-01

    ndice de Katz y la Escala de Lawton, respectivamente. Se definió como incapacidad funcional para cada dominio la necesidad de ayuda parcial o total para la realización de, como mínimo, una actividad de la vida diaria. Se empleó la regresión de Poisson con varianza robusta en los análisis bruto y ajustado considerándose el muestreo por conglomerados. RESULTADOS: La prevalencia de incapacidad para las actividades básicas fue de 26,8% (IC 95%:23,0;30,8 y la menor proporción de independencia fue para controlar funciones de orinar y/o evacuar. Para las actividades instrumentales, la prevalencia de incapacidad funcional fue de 28,8% (IC 95%:24,5;33,1, sobre todo para realizar traslados utilizando algún medio de transporte. Elevado porcentual de ancianos (21,7% presentó más de una actividad con incapacidad en las actividades instrumentales; ya en las actividades básicas, la mayor parte presentó dependencia para solo una actividad (16,6%. En el análisis ajustado, la incapacidad para las actividades básicas se asoció con color de la piel parda/negra/otras (p=0,01 y con el aumento de la edad (pOBJECTIVE: To assess the prevalence of disability and associated factors in elderly, by focusing on basic and instrumental activities of daily living. METHODS: This was a cross-sectional study on 598 subjects aged 60 years or over who were selected through two-stage cluster sampling in Pelotas, Southern Brazil, between 2007 and 2008. Basic and instrumental activities were evaluated using the Katz Index and the Lawton Scale, respectively. Disability relating to each domain was defined as the need for partial or total assistance to perform at least one activity of daily living. Poisson regression with robust variance was used in the crude and adjusted analyses, taking the cluster sampling into account. RESULTS: The prevalence of disability relating to basic activities was 26.8% (95% CI: 23.0; 30.8. The lowest proportion of independence was in relation to controlling the

  20. Study on the transplant impact on the elementary composition of Protousnea magellanica thallus by using instrumental neutron activation analysis; Estudio del impacto del transplante en la composicion elemental de Protousnea magellanica utilizando analisis por activacion neutronica instrumental

    Energy Technology Data Exchange (ETDEWEB)

    Bubach, Debora; Guevara, Sergio Ribeiro; Arribere, Maria A.; Wiesztort, Andres [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche. Lab. de Analisis por Activacion Nautronica; Calvelo, Susana [Universidad Nacional del Comahue, Bariloche (Argentina). Centro Regional Universitario Bariloche

    1999-11-01

    As part of a study on the use of the furticose lichen Protousnea magellanica as a bio indicator of atmospheric pollution, it was studied the impact on the elemental composition of the thallus when this lichen is transplanted in the same area under similar environmental conditions. The lichens were collected and replanted in a pristine area in Puerto Blest, Nahuel Huapi National Park, Bariloche, Argentina. After one year, the transplanted thalli were collected and analyzed by using Instrumental Activation Analysis, complemented with Atomic Absorption Spectrophotometry for the Pb content determination. Crustal inputs were identified by computing enrichment factors. The transplanted thalli concentrations of most of the elements under study, Al, As, Ba, Ce, Co, Cr, Dy, Eu, Hg, Fe, La, Lu, Mn, Na, Pb, Sb, Sc, Sm, Sr, Tb, Ti, Th, V, Yb and Zn, showed no significant differences with respect to the control thalli. However, some biological elements, Ca, Cl, Br, K and Rb, showed significant variations with respect to the controls, more noticeable in the first two elements. (author) 18 refs., 1 fig., 2 tabs.

  1. Advanced Neutron Source (ANS) Project

    Science.gov (United States)

    Campbell, J. H.

    1992-01-01

    This report discusses the following about the Advanced Neutron Source: Project Management; Research and Development; Fuel Development; Corrosion Loop Tests and Analyses; Thermal-Hydraulic Loop Tests; Reactor Control and Shutdown Concepts; Critical and Subcritical Experiments; Material Data, Structural Tests, and Analysis; Cold-Source Development; Beam Tube, Guide, and Instrument Development; Hot-Source Development; Neutron Transport and Shielding; I & C Research and Development; Design; and Safety.

  2. Neutron Radiography

    Science.gov (United States)

    Heller, A. K.; Brenizer, J. S.

    Neutron radiography and its related two-dimensional (2D) neutron imaging techniques have been established as invaluable nondestructive inspection methods and quantitative measurement tools. They have been used in a wide variety of applications ranging from inspection of aircraft engine turbine blades to study of two-phase fluid flow in operating proton exchange membrane fuel cells. Neutron radiography is similar to X-ray radiography in that the method produces a 2D attenuation map of neutron radiation that has penetrated the object being examined. However, the images produced differ and are often complementary due to the differences between X-ray and neutron interaction mechanisms. The uses and types of 2D neutron imaging have expanded over the past 15 years as a result of advances in imaging technology and improvements in neutron generators/sources and computers. Still, high-intensity sources such as those from reactors and spallation neutron sources, together with conventional film radiography, remain the mainstay of high-resolution, large field-of-view neutron imaging. This chapter presents a summary of the history, methods, and related variations of neutron radiography techniques.

  3. Hastes instrumentadas para a mensuração da resistência mecânica do solo Instrumented shanks for soil mechanical resistance measurements

    Directory of Open Access Journals (Sweden)

    Viacheslav I. Adamchuk

    2006-04-01

    Full Text Available A presença de camada de solo compactada pode significar sérios problemas ao desenvolvimento do sistema radicular das culturas em geral. A correção pode ser feita por métodos biológicos ou mecânicos. Uma das formas de diagnóstico da sua presença é com o uso de penetrômetros que exigem tempo considerável para a obtenção de dados. Com o advento dos recursos de espacialização das informações na forma de mapas, a necessidade de amostragem passou a ser ainda maior. Este trabalho reporta a busca de uma solução alternativa ao uso do penetrômetro. Envolve a geração de mapas de resistência mecânica do solo ao deslocamento de uma haste em três profundidades, baseado em três hastes instrumentadas, um receptor de GPS e um sistema de aquisição de dados. O sistema é acoplado a uma barra porta-ferramenta montada no engate de três pontos do trator. A configuração mostrou ser mecanicamente bastante simples e confiável. Dados de um teste inicial em campo demonstraram que o sistema pode produzir mapas que denotam a variabilidade espacial da referida resistência nas áreas amostradas, com alta resolução, densidade de amostragem elevada e com capacidade operacional ainda mais elevada se comparada com levantamentos feitos com métodos convencionais.The presence of soil compaction may be considered a serious problem for the development of crop root systems. It can be alleviated by biological or mechanical methods (such as tillage. One of the most popular diagnostic methods is based on standardized cone penetrometer measurements, which requires a considerable amount of time to obtain the data. With the advent of site-specific field management, high-density measurements have become a necessity. This work reports on an alternative approach to use a cone penetromenter. It involves the generation of maps of soil mechanical resistance at three depths using three instrumented blades, a GPS receiver and a data logger. The system is attached

  4. New Techniques in Neutron Scattering

    DEFF Research Database (Denmark)

    Birk, Jonas Okkels

    Neutron scattering is an important experimental technique in amongst others solid state physics, biophysics, and engineering. This year construction of European Spallation Source (ESS) was commenced in Lund, Sweeden. The facility will use a new long pulsed source principle to obtain higher...... potential performance than any existing facility, however in order to use this pulse structure optimally many existing neutron scattering instruments will need to be redesigned. This defense will concentrate on the design and optimization of the inverse time-of-flight cold neutron spectrometer CAMEA...

  5. Use of cold neutrons for condensed matter research at the neutron guide laboratory ELLA in Juelich

    Energy Technology Data Exchange (ETDEWEB)

    Schaetzler, R.; Monkenbusch, M. [Research Centre Juelich, D-52425 Juelich (Germany)

    1998-07-01

    Cold neutrons produced in the FRJ-2 DIDO reactor are guided into the external hall ELLA. It hosts 10 instruments that are red by three major neutron guides. Cold neutrons allow for diffraction and small angle scattering experiments resolving mesoscopic structures (1 to 100 nm). Contrast variation by isotopic substitution in chemically identical species yields information uniquely accessible bi neutrons. Inelastic scattering of cold neutrons allows investigating slow molecular motions because the low neutron velocity results in large relative velocity changes even at small energy transfers. The SANS machines and the HADAS reflectometer serve as structure probes and the backscattering BSS1 and spin-echo spectrometers NSE as main dynamics probes. Besides this the diffuse scattering instrument DNS and the lattice parameter determination instrument LAP deal mainly with crystals and their defects. Finally the beta-NMR and the EKN position allow for methods other than scattering employing nuclear reactions for solid state physics, chemistry and biology/medicine. (author)

  6. Production of a {sup 44} Ti target and its cross section of thermal neutron capture; Producao de um alvo de {sup 44} Ti e sua secao de choque para captura de neutrons termicos

    Energy Technology Data Exchange (ETDEWEB)

    Ejnisman, R

    1993-12-31

    A study of the production of a {sup 44} Ti target was carried out aiming the determination of its thermal neutron capture cross-section. With this purpose, the cross-section of the reaction {sup 45} Sc(p,2 n) {sup 44} Ti was determined in the energies 16-, 18-, 20-22- and 45 MeV. The cross-section of the reactions (p,n) {sup 45} Ti, (p,pn) {sup 44m} Sc, (p,pn) {sup 44g} Sc and (p,p2n){sup 43} Sc were also measured. The results in the low energy region are in good agreement with a previous work by McGee et al. On the other hand, the cross-section at 45 MeV is different from McGee`s result and indicates the existence of an abnormal behavior of the excitation function at higher energies. Furthermore, a radiochemical separation method was developed in order to eliminate Sc from the {sup 44} Ti target which was irradiated with neutrons. It was possible to determine an upper limit for the cross-section of the reaction {sup 44} Ti (n, {gamma}) of 4 x 10{sup 3} b. At last, it is presented a discussion of the results obtained and their possible astrophysical implications. (author) 94 refs.

  7. Problems of interference and geometry of the detectors in a beam tube for the determination of the neutron spectra; Problemas de interferencia y geometria de los detectores en un tubo de haces para la determinacion del espectro de neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Paredes G, L.C

    1991-11-15

    The detector materials were selected and proved for the thermal, intermediate and quick energy intervals of the neutron spectra, in the radial tube RW-2 to 1 MW of thermal power during 5 min, being obtained good results respect to the activation of the thin sheets. However, since the exhibition speed, of each experimental arrangement after it irradiation that was of the order of 2 R/h, it was considered that may be more convenient the irradiation, separated from each thin sheet, for that which it was selected the SINCA irradiation system, because it simplified the activities related with the individual irradiation of the thin sheets and the count of the same ones. It was found that the selection, the geometric arrangement and measurement of the activities of the used thin sheets, its are the three factors that more affect the input data of the SAND II code that it will be used in our case for the determination of the neutron spectra of the Reactor. (Author)

  8. The CIEMAT Neutron Standards Laboratory (LPN): National Reference Facility for the Calibration of Neutron Measurement Equipment; El Laboratorio de Patrones Neutronicos del CIEMAT: instalacion de referencia nacional para la calibracion de equipos de medida neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Mendez, R.

    2014-04-01

    This is a new facility that, in keeping with the recommendations of standard ISO 8529:1, has 20m5-Be and 252Cf neutron sources stored in water inside a 9 m x 7.5 m x 8 m Irradiation Room with 1.25 m concrete walls that is accessed through a 6.5 ton sliding shielded door. These sources are remotely handled from the Control Room by means of a system that places them in the geometric center of the room and aligns them with the equipment or materials to be irradiated arranged on a base plate. The facility has a series of interlocks that guarantee safety during operations with sources, and the verification measurements have demonstrated the suitability of the shielding used. The LPN will be the answer to the demand for a national laboratory for neutron measurement equipment calibration and equipment and material irradiation under controlled conditions, and it will position our country at the same level as our European partners. (Author)

  9. Drawing up of a procedure for vanadium determination in mussels using the neutron activation analysis method; Estabelecimento de procedimento para determinacao de vanadio em mexilhoes pelo metodo de analise por ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Daniele, E-mail: danyseo@uol.com.b [Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil). Centro de Ciencias Biologicas e da Saude; Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Vasconcellos, Marina B.A.; Saiki, Mitiko; Catharino, Marilia G.M.; Moreira, Edson G., E-mail: mbvascon@ipen.b, E-mail: mitiko@ipen.b, E-mail: mgcatharino@uol.com.b, E-mail: emoreira@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Sousa, Eduinetty C.P.M. de; Pereira, Camilo D.S., E-mail: edvinett@usp.b, E-mail: camilo.pereira@usp.b [Universidade de Sao Paulo (IO/USP), SP (Brazil). Inst. Oceanografico. Lab. de Ecotoxicologia Marinha

    2009-07-01

    This work establishes an adequate procedure for obtaining reliable results for determination of vanadium in mussels, leg by leg by the neutron activation analysis (NAA), viewing the posterior application on the bio monitoring the coastal pollution, particularly near the petroleum terminals.For the evaluation of result quality concerning to the quality of those results, the work analysed the reference material certification NIST SRM 1566b Oyster Tissue. The precision of the results were also analysed using repetitions of mussel samples collected at the coastal of northern Sao Paulo state, Brazil. The NAA procedure consisted of 200 mg of sample and a synthetic standard of vanadium during a period of 8 s and under a thermal neutron flux of 6.6 x 10{sup 12} n cm{sup -2} s{sup -1} at the pneumatic station 4 of the IEA-R1 nuclear reactor of IPEN-CNEN/SP. After a 3 min decay, the measurements of the gamma activities of the sample and the standard were done using a Ge hyper pure semi-conductor detector, connected to gamma ray multichannel analyser. The vanadium were determined by the measurement of the gamma activity of the {sup 52}V through the 1434.08 keV peak, and half-life time of 3.75 min. The concentration of V were calculated by the comparative method. The obtained results indicated the viability of the NAA procedure established for the determination of vanadium in mussels

  10. Application of COMSOL in the solution of the neutron diffusion equations for fast nuclear reactors in stationary state; Aplicacion de COMSOL en la solucion de las ecuaciones de difusion de neutrones para reactores nucleares rapidos en estado estacionario

    Energy Technology Data Exchange (ETDEWEB)

    Silva A, L.; Del Valle G, E., E-mail: evalle@ipn.mx [IPN, Escuela Superior de Fisica y Matematicas, Av. IPN s/n, Col. San Pedro Zacatenco, 07738 Mexico D. F. (Mexico)

    2012-10-15

    This work shows an application of the program COMSOL Multi physics Ver. 4.2a in the solution of the neutron diffusion equations for several energy groups in nuclear reactors whose core is formed by assemblies of hexagonal transversal cut as is the cas of fast reactors. A reference problem of 4 energy groups is described of which takes the cross sections which are processed by means of a program that prepares the definition of the constants utilized in COMSOL for the generic partial differential equations that this uses. The considered solution domain is the sixth part of the core which is applied frontier conditions of reflection and incoming flux zero. The discretization mesh is elaborated in automatic way by COMSOL and the solution method is one of finite elements of Lagrange grade two. The reference problem is known as the Knk with and without control rod which led to propose the calculation of the effective multiplication factor in function of the control rod fraction from a value 0 (completely inserted control rod) until the value 1 (completely extracted control rod). Besides this the reactivity was determined as well as the change of this in function of control rod fraction. The neutrons scalar flux for each energy group with and without control rod is proportioned. The reported results show a behavior similar to the one reported in other works but using the discreet ordinates S{sub 2} approximation. (Author)

  11. 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...

  12. Neutron Sources for Standard-Based Testing

    Energy Technology Data Exchange (ETDEWEB)

    Radev, Radoslav [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McLean, Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-11-10

    The DHS TC Standards and the consensus ANSI Standards use 252Cf as the neutron source for performance testing because its energy spectrum is similar to the 235U and 239Pu fission sources used in nuclear weapons. An emission rate of 20,000 ± 20% neutrons per second is used for testing of the radiological requirements both in the ANSI standards and the TCS. Determination of the accurate neutron emission rate of the test source is important for maintaining consistency and agreement between testing results obtained at different testing facilities. Several characteristics in the manufacture and the decay of the source need to be understood and accounted for in order to make an accurate measurement of the performance of the neutron detection instrument. Additionally, neutron response characteristics of the particular instrument need to be known and taken into account as well as neutron scattering in the testing environment.

  13. Neutron Albedo

    CERN Document Server

    Ignatovich, V K

    2005-01-01

    A new, algebraic, method is applied to calculation of neutron albedo from substance to check the claim that use of ultradispersive fuel and moderator of an active core can help to gain in size and mass of the reactor. In a model of isotropic distribution of incident and reflected neutrons it is shown that coherent scattering on separate grains in the case of thermal neutrons increases transport cross section negligibly, however it decreases albedo from a wall of finite thickness because of decrease of substance density. A visible increase of albedo takes place only for neutrons with wave length of the order of the size of a single grain.

  14. Neutron detectors for scattering experiments at HANARO

    Indian Academy of Sciences (India)

    Myungkook Moon; Changhee Lee; Jongkyu Cheon; Younghyun Choi; Harkrho Kim; Shraddha S Desai

    2008-11-01

    Position sensitive detectors (PSD) measure the distribution of scattered neutrons and are essential tools for neutron scattering experiments. Various types of neutron detectors used at neutron diffractometers are conventional tube detectors, 1-D and 2-D PSDs. Korea Atomic Energy Research Institute (KAERI) has been developing various kinds of PSDs to improve the instrument performance and to develop new scattering instruments. Our development work is initiated with 1-D PSD for residual stress analysis spectrometer and finally the technology is extended to development of 2-D PSD with planar and curved geometry. All PSDs are based on multiwire grid assembly with delay line readout method for position encoding, as the response is faster than charge division method and enables higher count rate capability. Design details and operational characteristics of some of the PSDs developed, for application at neutron scattering instruments are presented.

  15. Neutron thermalization in quality control of asphalts content in mixtures for paving. Adaptation of nuclear densimeters for this purpose; La termalizacion de neutrones en el control de calidad de contenido de asfalto en mezclas para pavimentos. Adaptacion de densimetros nucleares para tal fin

    Energy Technology Data Exchange (ETDEWEB)

    Bravo R, T.; Montanez M, P.O. [Instituto de Investigaciones y Formacion Avanzada, Boyaca (Colombia). Facultad de Ciencias. Lab. Nuclear

    1995-12-31

    This paper shows how the neutron source of the nuclear densimeters, used for measure the humidity, can be used for measuring and making the quality control of the asphalt percentage in mixtures used for street paving. The measures are based in the neutronic thermalization processes, because the hydrogen is the main part of chemical composition of the asphalts. A calibration method for the equipment is presented. (author). 6 refs, 3 figs, 3 tabs.

  16. Genetic algorithms used to optimize an artificial neural network design used in neutron spectrometry; Algoritmos geneticos utilizados para optimizar un diseno de red neuronal artificial usado en espectrometria de neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Arteaga A, T.; Ortiz R, J. M.; Vega C, H. R., E-mail: tarcicio70@yahoo.co.uk [Universidad Autonoma de Zacatecas, Av. Lopez Velarde 117, 98600 Zacatecas, Zac. (Mexico)

    2016-10-15

    Artificial neural networks (Ann) are widely used; it which consist of an input layer, one or more hidden layers and an output layer; these layers contain neurons and each has connections called weights, where the knowledge are allowed and let to Ann solve problems proposed. These Ann is used to reconstruction of the energy spectrum of neutrons from count rates and develop Bonner sphere neutron dosimetry. Currently, we have developed Ann with high performance and generalization ability. Determine your optimal architecture is usually a difficult task, an exhaustive search of all possible combinations of parameters is rarely possible further training of the neural network with random initial weights can cause two major drawbacks: it can stuck in local minima or converge very slowly. In this project it will be used Genetic Algorithms (Ga); which are based on the principle or analogy of evolution through natural selection and has shown to be very effective in optimizing complex search functions and large spaces or to find a near optimal overall efficiency. The aim is to decrease the architecture in number of hidden neurons and therefore the total number of connections is reducing. The benefits obtained by optimizing the network are that the number of connections would be considerably smaller and thus the computational complexity, hardware integration, resources will be lower such that will allow to be even more viable implemented. To use the Ga three problems must be solve: 1) coding the problem into chromosomes. 2) Construct a fitness function. 3) Proper selection of genetic operators; crossover, selection, mutation. As a result, the scientific knowledge obtained can to be applied to similar problems having a reference parameters used and their impact on the optimization would to be generated. It concluded that the input layer and output are subject to the problem; the Ga propose the optimal number of neurons in the hidden layer without losing the quality of the

  17. Optimization of the architecture of a neural network in neutron spectrometry to reduce the number of Bonner spheres; Optimizacion de la arquitectura de una red neuronal en espectrometria de neutrones para reducer el numero de esferas Bonner

    Energy Technology Data Exchange (ETDEWEB)

    Leon P, A. A.; Martinez B, M. R.; Hernandez P, C. F.; Espinoza G, J. G.; Castaneda M, V. H.; Solis S, L. O.; Castaneda M, R.; Ortiz R, J. M.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Av. Ramon Lopez Velarde 801, Col. Centro, 98000 Zacatecas, Zac. (Mexico); Mendez V, R. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Laboratorio de Patrones Neutronicos, Av. Complutense 22, 28040 Madrid (Spain); Gallego, E. [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, ETSI Industriales, Jose Gutierrez Abascal 2, 28006 Madrid (Spain); De Sousa L, M. A. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    The neutron spectrometry is an experimental process for determining the energy distribution called the Spectrum. Among the methods available for neutron spectrometry, one can mention the Bonner Sphere Spectrometric System as one of the most used, consisting of a detector placed in the center of a set of polyethylene spheres whose diameters range from 2 to 18 inches, however has some disadvantages such as the long periods of time to perform the measurements, the weight and the spheres number that vary according to the system. From this, alternative methods such as artificial neural networks are proposed. For this project neural networks of reverse propagation were used with the methodology of robust design of artificial neural networks, with the aid of a computational tool that maximizes the performance, making the time used for the training s of the network is the smallest possible and thus gets the orthogonal fixes quickly to determine the best network topology. The counting rates of a spectrometric system with 7 spheres, 2 spheres and one sphere of 5 and 8 inches were used. This methodology seeks to reduce the work used as in the spectrometric system formed by a greater number of spheres, since to enter less data in the counting rates to obtain the spectra with 60 energy levels saves time and space, because at having a smaller number of spheres its portability is easier to move from one place to another, for this we performed several experiments with different errors until we reached the optimal error so that the topology of the network was appropriate and find the best design parameters. A statistical software JMP was also used to obtain the best topologies and thus to retrain obtaining its best and worst spectra, in order to determine if the reduction is possible. (Author)

  18. 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

  19. Neutron Detection with Cryogenics and Semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    bell, Z.W.; Carpenter, D.A.; Cristy, S.S.; Lamberti, V.E.

    2005-03-10

    The common methods of neutron detection are reviewed with special attention paid to the application of cryogenics and semiconductors to the problem. The authors' work with LiF- and boron-based cryogenic instruments is described as well as the use of CdTe and HgI{sub 2} for direct detection of neutrons.

  20. A polyethylene-B4C based concrete for enhanced neutron shielding at neutron research facilities

    Science.gov (United States)

    DiJulio, D. D.; Cooper-Jensen, C. P.; Perrey, H.; Fissum, K.; Rofors, E.; Scherzinger, J.; Bentley, P. M.

    2017-07-01

    We present the development of a specialized concrete for neutron shielding at neutron research facilities, based on the addition of hydrogen atoms in the form of polyethylene and also B4C for enhancing the neutron capture properties of the concrete. We show information on the mechanical properties of the concrete and the neutronics, in particular its relevance to modern spallation neutron sources, such as the European Spallation Source (ESS), currently under construction in Lund, Sweden. The new concrete exhibits a 15% lower mass density, a compressible strength of 50% relative to a standard concrete and a significant increase in performance of shielding against MeV neutrons and lower energies. The concrete could find application at the ESS in for example common shielding components, individual beamline shielding and instrument caves. Initial neutronic tests of the concrete, carried out at Lund University, have also verified the performance in the MeV neutron energy range and the results are presented.

  1. Validation of virtual instrument for data analysis in metrology of time and frequency; Validacao do instrumento virtual para analise de dados em metrologia de tempo e frequencia

    Energy Technology Data Exchange (ETDEWEB)

    Jordao, Bruno; Quaresma, Daniel; Rocha, Pedro; Carvalho, Ricardo, E-mail: bjordan@on.br [Observatorio Nacional (ON), Rio de Janeiro, RJ (Brazil). Laboratorio Primario de Tempo e Frequencia; Peixoto, Jose Guilherme [Instituto de Radioprotecao e Dosimetria (LNMRI/IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Laboratorio Nacional de Metrologia das Radiacoes Ionizantes

    2016-07-01

    Commercial Software (CS) for collection, analysis and plot time and frequency data plots are being increasingly used in reference laboratories worldwide. With this, it has greatly improved the results of calculations of uncertainty for these values. We propose the creation of a collection of software and data analysis using Virtual Instruments (VI) developed the Primary Laboratory Time and frequency of the National Observatory - ON and validation of this instrument. To validate the instrument developed, it made a comparative analysis between the results obtained (VI) with the results obtained by (CS) widely used in many metrology laboratories. From these results we can conclude that there was equivalence between the analyzed data. (author)

  2. La Comprensión Narrativa en Edad Preescolar: Un Instrumento para su Medición Narrative Comprehension in the Preschool Age: An Assessment Instrument

    National Research Council Canada - National Science Library

    Katherine Strasser; Antonia Larraín; Soledad López de Lérida; María Rosa Lissi

    2010-01-01

    La comprensión narrativa es una habilidad fundamental en la alfabetización infantil, poco atendida por investigadores y educadores por las dificultades para comprenderla y medirla, sobre todo a edades tempranas...

  3. Neutron reflectometry

    DEFF Research Database (Denmark)

    Klösgen-Buchkremer, Beate Maria

    2014-01-01

    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......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...

  4. Filosofia Negativa e Arte: Instrumentos e Roupagens para se Pensar a Educacao (Negative Philosophy and Art: Instruments and Clothing for Thinking about Education).

    Science.gov (United States)

    Pucci, Bruno

    2000-01-01

    Synthesizes philosophical and aesthetic insights taken from "Negative Dialectics" (Theodor Adorno) and freely developed from the illuminating sparks generated by the shock of words and things named. Aims to create instruments and clothing for the negative analysis of education. (BT)

  5. Filosofia Negativa e Arte: Instrumentos e Roupagens para se Pensar a Educacao (Negative Philosophy and Art: Instruments and Clothing for Thinking about Education).

    Science.gov (United States)

    Pucci, Bruno

    2000-01-01

    Synthesizes philosophical and aesthetic insights taken from "Negative Dialectics" (Theodor Adorno) and freely developed from the illuminating sparks generated by the shock of words and things named. Aims to create instruments and clothing for the negative analysis of education. (BT)

  6. Aerial Neutron Detection: Neutron Signatures for Nonproliferation and Emergency Response Applications

    Energy Technology Data Exchange (ETDEWEB)

    Maurer, Richard J.; Stampahar, Thomas G.; Smith, Ethan X.; Mukhopadhyay, Sanjoy; Wolff, Ronald S.; Rourke, Timothy J.; LeDonne, Jeffrey P.; Avaro, Emanuele; Butler, D. Andre; Borders, Kevin L.; Stampahar, Jezabel; Schuck, William H.; Selfridge, Thomas L.; McKissack, Thomas M.; Duncan, William W.; Hendricks, Thane J.

    2012-10-17

    From 2007 to the present, the Remote Sensing Laboratory has been conducting a series of studies designed to expand our fundamental understanding of aerial neutron detection with the goal of designing an enhanced sensitivity detection system for long range neutron detection. Over 35 hours of aerial measurements in a helicopter were conducted for a variety of neutron emitters such as neutron point sources, a commercial nuclear power reactor, nuclear reactor spent fuel in dry cask storage, depleted uranium hexafluoride and depleted uranium metal. The goals of the project were to increase the detection sensitivity of our instruments such that a 5.4 × 104 neutron/second source could be detected at 100 feet above ground level at a speed of 70 knots and to enhance the long-range detection sensitivity for larger neutron sources, i.e., detection ranges above 1000 feet. In order to increase the sensitivity of aerial neutron detection instruments, it is important to understand the dynamics of the neutron background as a function of altitude. For aerial neutron detection, studies have shown that the neutron background primarily originates from above the aircraft, being produced in the upper atmosphere by galactic cosmic-ray interactions with air molecules. These interactions produce energetic neutrons and charged particles that cascade to the earth’s surface, producing additional neutrons in secondary collisions. Hence, the neutron background increases as a function of altitude which is an impediment to long-range neutron detection. In order to increase the sensitivity for long range detection, it is necessary to maintain a low neutron background as a function of altitude. Initial investigations show the variation in the neutron background can be decreased with the application of a cosmic-ray shield. The results of the studies along with a representative data set are presented.

  7. Ex-core instrumentation; Instrumentation hors coeur des reacteurs

    Energy Technology Data Exchange (ETDEWEB)

    Burel, J.P. [Schneider Electric S.A., 92 - Boulogne-Billancourt (France)

    1999-01-01

    The safety and the control of the reactor need to master the nuclear power from the core radiation measurement. According to the reactor dimensions and conception, the nuclear parameters monitoring is realized through two instrumentation systems: the ex-core instrumentation system which use detector placed outside of the core and the in-core instrumentation system. This paper deals with the ex-core systems based on neutronic measurements and details the detectors choice, the treatment circuits, data processing, realizations in France and also example of the Wwr reactor instrumentation. (A.L.B.)

  8. Radiation Fields in the Vicinity of Compact Accelerator Neutron Generators

    Energy Technology Data Exchange (ETDEWEB)

    David L. Chichester; Brandon W. Blackburn; Augustine J. Caffrey

    2006-10-01

    Intense pulsed radiation fields emitted from sealed tube neutron generators provide a challenge for modern health physics survey instrumentation. The spectral sensitivity of these survey instruments requires calibration under realistic field conditions while the pulsed emission characteristics of neutron generators can vary from conditions of steady-state operation. As a general guide for assessing radiological conditions around neutron generators, experiments and modeling simulations have been performed to assess radiation fields near DD and DT neutron generators. The presence of other materials and material configurations can also have important effects on the radiation dose fields around compact accelerator neutron generators.

  9. Application of Laplace transform for determination of albedo type boundary conditions for neutronic calculations; Aplicacao da transformada de Laplace para determinacao de condicoes de contorno tipo albedo para calculos neutronicos

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Claudio Zen

    2008-07-01

    In this dissertation we use the Laplace transform to derive expressions for nonstandard albedo boundary conditions for one and two non-multiplying regions at the ends of one dimensional domains. In practice, the fuel regions of reactor cores are surrounded by reflector regions that reduce neutron leakage. In order to exclude the reflector regions from the calculations, we introduce a reflection coefficient or albedo. We use the present albedo boundary conditions to solve numerically slab-geometry monoenergetic and multigroup diffusion equations using the conventional finite difference method. Numerical results are generated for fixed source and eigenvalue diffusion problems in slab geometry(author)

  10. The SINQ instrument control software system

    Science.gov (United States)

    Heer, H.; Könnecke, M.; Maden, D.

    The spallation neutron source SINQ at Villigen, Switzerland, is a continuous source with a flux of about 10 14 n/s cm 2. Nine neutron-scattering instruments will come into operation within the first year, seven of them are situated at neutron guides. The electronics and software required for the various instruments are standardized as far as possible. The SINQ instrument control software (SICS) is implemented as a client server system. The SICS server is implemented in ANSI-C on a digital Unix platform and uses only Posix compliant system calls for maximum portability. Clients provide the user interface, which may be either of the traditional command line type or a more modern graphical user interface. Communication with the front-end electronics is via the TCP/IP internet protocol. Measured data are stored in the NeXus format, a common data exchange format for neutron scattering and X-ray instruments.

  11. El Manual FIM, Modelo de Excelencia Organizacional: un Instrumento para Proyectos de Asistencia Técnica Integral a PYMES (The FIM Manual for organizational excellence: an instrument for integral techniques assistance to SMEs

    Directory of Open Access Journals (Sweden)

    Francisco Javier Rodríguez Sánchez

    2012-12-01

    Full Text Available La complejidad creciente del entorno en que se desenvuelvenlas empresas hace necesario que éstas desarrollencapacidades para mejorar su competitividad para alcanzar laexcelencia y afrontar con garantías los nuevos retos. Con laevolución del principio de “excelencia”, se dio paso a una nociónmás amplia e integradora, la cual se incluye en modelosde excelencia organizacional como el Modelo EFQM (de laEuropean Foundation for Quality Management o el del PremioMalcolm Baldrige. Esos modelos permiten conceptuar hitos yfases de desarrollo para realizar proyectos para el mejoramientocompetitivo de las empresas. En este artículo se presenta elManual FIM, en su cuarta revisión, coherente con los citadosmodelos, como instrumento para medir la capacidad de gestiónde la calidad y la productividad de las pequeñas y medianasempresas. Su metodología, particularizada para estas empresasen Venezuela, permite el despliegue de proyectos de asistenciatécnica integral, que se desenvuelven en un entorno complejoy cambiante.   ABSTRACT The environment´s growing complexity requires thatcompanies develop capabilities to improve their competivenessto reach excellence and be able to adequately face newchallenges. The evolution of the widest and most coveringexcellence definition is expressed by organizational excellencestandards such as the “EFQM model” or the “MalcolmBaldrige Prize”. These models specify the developmentphases and milestones for projects striving to achievecompetitive improvement in any company. This articleexamines the “FIM Manual” Ver. 4, similar to the abovementioned models, when used as an instrument to measurethe managing and production capabilities of small and mediumsize enterprises (SMEs. Its methodology, adapted forVenezuelan SMEs, allows its application in integral technicalassistance projects being developed in a changing andcomplex environment.

  12. A neutron activation spectrometer and neutronic experimental platform for the National Ignition Facility (invited)

    Science.gov (United States)

    Yeamans, C. B.; Gharibyan, N.

    2016-11-01

    At the National Ignition Facility, the diagnostic instrument manipulator-based neutron activation spectrometer is used as a diagnostic of implosion performance for inertial confinement fusion experiments. Additionally, it serves as a platform for independent neutronic experiments and may be connected to fast recording systems for neutron effect tests on active electronics. As an implosion diagnostic, the neutron activation spectrometers are used to quantify fluence of primary DT neutrons, downscattered neutrons, and neutrons above the primary DT neutron energy created by reactions of upscattered D and T in flight. At a primary neutron yield of 1015 and a downscattered fraction of neutrons in the 10-12 MeV energy range of 0.04, the downscattered neutron fraction can be measured to a relative uncertainty of 8%. Significant asymmetries in downscattered neutrons have been observed. Spectrometers have been designed and fielded to measure the tritium-tritium and deuterium-tritium neutron outputs simultaneously in experiments using DT/TT fusion ratio as a direct measure of mix of ablator into the gas.

  13. Radiative neutron capture as a counting technique at pulsed spallation neutron sources: a review of current progress

    Science.gov (United States)

    Schooneveld, E. M.; Pietropaolo, A.; Andreani, C.; Perelli Cippo, E.; Rhodes, N. J.; Senesi, R.; Tardocchi, M.; Gorini, G.

    2016-09-01

    Neutron scattering techniques are attracting an increasing interest from scientists in various research fields, ranging from physics and chemistry to biology and archaeometry. The success of these neutron scattering applications is stimulated by the development of higher performance instrumentation. The development of new techniques and concepts, including radiative capture based neutron detection, is therefore a key issue to be addressed. Radiative capture based neutron detectors utilize the emission of prompt gamma rays after neutron absorption in a suitable isotope and the detection of those gammas by a photon counter. They can be used as simple counters in the thermal region and (simultaneously) as energy selector and counters for neutrons in the eV energy region. Several years of extensive development have made eV neutron spectrometers operating in the so-called resonance detector spectrometer (RDS) configuration outperform their conventional counterparts. In fact, the VESUVIO spectrometer, a flagship instrument at ISIS serving a continuous user programme for eV inelastic neutron spectroscopy measurements, is operating in the RDS configuration since 2007. In this review, we discuss the physical mechanism underlying the RDS configuration and the development of associated instrumentation. A few successful neutron scattering experiments that utilize the radiative capture counting techniques will be presented together with the potential of this technique for thermal neutron diffraction measurements. We also outline possible improvements and future perspectives for radiative capture based neutron detectors in neutron scattering application at pulsed neutron sources.

  14. Neutron activation analysis application for determining iron concentration in forage grasses used in intensive cattle production system; Aplicacao da analise por ativacao com neutrons para determinacao de ferro em forrageiras usadas no sistema intensivo de producao de bovinos de leite

    Energy Technology Data Exchange (ETDEWEB)

    Armelin, Maria Jose A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Primavesi, Odo [Empresa Brasileira de Pesquisa Agropecuaria, Sao Carlos, SP (Brazil). Centro de Pesquisa de Pecuaria do Sudeste

    2002-07-01

    Iron is an essential element to the life. It is an important hemoglobin component and it is involved in the transport of oxygen to cells. A deficiency of iron results in an unsuitable synthesis of hemoglobin and a delay in the growth. Iron contents above the tolerable level in animal feed can cause serious damages to the health and the death in extreme cases. The forages are the main source of feed to cattle in grazing. It is known from the literature, that the growth and the nutritious value of the forage are influenced by specie and physiologic age of the plant, soil fertility and environmental conditions. Therefore, an agronomical evaluations of the forages are necessary before to introduce in an intensive cattle production systems to program adequate grazing management. Neutron activation analysis was applied to evaluate the Fe concentration in the main tropical forage grasses used in intensive dairy cattle production systems in Sao Carlos, SP, Brazil. Iron concentrations were smaller in the rain season than in the dry one. Comparison of results obtained in the analyses of forages with daily requirements of iron in dry matter, showed that the Fe concentration in forages was adequate. (author)

  15. Dosimetric evaluation of spectrophotometric response of alanine gel solution for gamma, photons, electrons and thermal neutrons radiations; Avaliacao dosimetrica da resposta espectrofotometrica da solucao gel de alanina para radiacao gama, de fotons, de eletrons e de neutrons termicos

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cleber Feijo

    2009-07-01

    Alanine Gel Dosimeter is a new gel material developed at IPEN that presents significant improvement on Alanine system developed by Costa. The DL-Alanine (C{sub 3}H{sub 7}NO{sub 2}) is an amino acid tissue equivalent that improves the production of ferric ions in the solution. This work aims to analyse the main dosimetric characteristics this new gel material for future application to measure dose distribution. The performance of Alanine gel solution was evaluated to gamma, photons, electrons and thermal neutrons radiations using the spectrophotometry technique. According to the obtained results for the different studied radiation types, the reproducibility intra-batches and inter-batches is better than 4% and 5%, respectively. The dose response presents a linear behavior in the studied dose range. The response dependence as a function of dose rate and incident energy is better 2% and 3%, respectively. The lower detectable dose is 0.1 Gy. The obtained results indicate that the Alanine gel dosimeter presents good performance and can be useful as an alternative dosimeter in the radiotherapy area, using MRI technique for tridimensional dose distribution evaluation. (author)

  16. Development of a computational model for the calculation of neutron dose equivalent in laminated primary barriers of radiotherapy rooms; Desenvolvimento de um modelo computacional para calculo do equivalente de dose de neutrons em barreiras primarias laminadas de salas de radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Rezende, Gabriel Fonseca da Silva

    2015-06-01

    Many radiotherapy centers acquire 15 and 18 MV linear accelerators to perform more effective treatments for deep tumors. However, the acquisition of these equipment must be accompanied by an additional care in shielding planning of the rooms that will house them. In cases where space is restricted, it is common to find primary barriers made of concrete and metal. The drawback of this type of barrier is the photoneutron emission when high energy photons (e.g. 15 and 18 MV spectra) interact with the metallic material of the barrier. The emission of these particles constitutes a problem of radiation protection inside and outside of radiotherapy rooms, which should be properly assessed. A recent work has shown that the current model underestimate the dose of neutrons outside the treatment rooms. In this work, a computational model for the aforementioned problem was created from Monte Carlo Simulations and Artificial Intelligence. The developed model was composed by three neural networks, each being formed of a pair of material and spectrum: Pb18, Pb15 and Fe18. In a direct comparison with the McGinley method, the Pb18 network exhibited the best responses for approximately 78% of the cases tested; the Pb15 network showed better results for 100% of the tested cases, while the Fe18 network produced better answers to 94% of the tested cases. Thus, the computational model composed by the three networks has shown more consistent results than McGinley method. (author)

  17. Comparación de la dinámica en tiempo real de los métodos mínimos cuadrados y variable instrumental para estimación de parámetros

    OpenAIRE

    Jesús Medel Juárez, José de; Guevara López, Pedro

    2002-01-01

    En este trabajo se presenta un análisis comparativo de la dinámica en Tiempo Real de los métodos de estimación: Mínimos Cuadrados (MC) y Variable Instrumental (VI), para sistemas lineales estacionarios e invariantes en el tiempo que contienen perturbaciones internas y externas, correlacionadas con el estado observable del tipo una entrada una salida. Al utilizar las teorías de procesos estocásticos y Filtrado en Tiempo Real dentro del análisis teórico, se presentan algunas diferencias bási...

  18. Propuesta metodológica, para la optimización de los procesos de gestión en el proyecto esctracurricular Banda instrumental Escuela de Riojalandia y su impacto en el entorno educativo

    OpenAIRE

    Solera-Salas, Mario

    2012-01-01

    tesis de maestría -- Universidad de Costa Rica. La propuesta es parte del trabajo final de graduación “Análisis de los procesos de gestión del proyecto extracurricular “Banda Instrumental Escuela Riojalandia”, del mismo autor, 2011 Propuesta de trabajo para que funcionarios (as) docentes y administrativos conozcan y apliquen en sus especialidades, el sistema de trabajo de los grupos musicales, con el objetivo de aprovechar el desarrollo del trabajo colaborativo en esos grupos. Se diseñó pa...

  19. Optimizing moderator dimensions for neutron scattering at the spallation neutron source.

    Science.gov (United States)

    Zhao, J K; Robertson, J L; Herwig, Kenneth W; Gallmeier, Franz X; Riemer, Bernard W

    2013-12-01

    In this work, we investigate the effect of neutron moderator dimensions on the performance of neutron scattering instruments at the Spallation Neutron Source (SNS). In a recent study of the planned second target station at the SNS facility, we have found that the dimensions of a moderator play a significant role in determining its surface brightness. A smaller moderator may be significantly brighter over a smaller viewing area. One of the immediate implications of this finding is that for modern neutron scattering instrument designs, moderator dimensions and brightness have to be incorporated as an integrated optimization parameter. Here, we establish a strategy of matching neutron scattering instruments with moderators using analytical and Monte Carlo techniques. In order to simplify our treatment, we group the instruments into two broad categories: those with natural collimation and those that use neutron guide systems. For instruments using natural collimation, the optimal moderator selection depends on the size of the moderator, the sample, and the moderator brightness. The desired beam divergence only plays a role in determining the distance between sample and moderator. For instruments using neutron optical systems, the smallest moderator available that is larger than the entrance dimension of the closest optical element will perform the best (assuming, as is the case here that smaller moderators are brighter).

  20. A abordagem instrumental para o estudo da integração da tecnologia na prática pedagógica do professor de matemática The instrumental approach for the technology integration in the pedagogical practice of the mathematics teacher study

    Directory of Open Access Journals (Sweden)

    Marilena Bittar

    2011-01-01

    Full Text Available Neste texto discutimos uma forma de investigação sobre a apropriação da tecnologia pelo professor de matemática e seu uso em sua prática pedagógica. Apresentamos a abordagem instrumental que fornece elementos teóricos apropriados para esse estudo. Esta teoria apoia-se em conceitos da psicologia, em especial na ideia de esquema definida por Piaget e utilizada por Vergnaud, na teoria dos campos conceituais. Serão abordados somente alguns elementos da teoria, os que permitem compreender o uso de um software nas aulas de Matemática. É dada especial atenção ao conceito de gênese instrumental e, para isso, à distinção entre artefato e instrumento, e entre instrumentalização e instrumentação. A partir destes elementos e da distinção que fazemos entre inserir e integrar a tecnologia na prática pedagógica do professor de matemática são apresentados resultados de uma pesquisa-ação realizada com professores dessa disciplina.This paper deals with a certain way to investigate the mastering of technology by mathematics teachers and its use in their pedagogical practice. The instrumental approach which brings the suitable theoretical elements to this study is presented. This instrumental approach is supported by some psychological Piaget's constructs, specially that one of schemata that is also assumed by Vergnaud in his theory of conceptual fields. Only the theoretical elements that make possible the understanding of a software implementation at mathematics lessons will be exposed. Special attention is given to the concept of instrumental genesis in order to make the distinction between artifact and instrument, and between instrumentalization and instrumentation. Results of an action-research realized with mathematics teachers are described based on those theoretical elements and on the proposed difference between inserting and integrating technology into the pedagogical practice in the mathematics teaching.

  1. Passive neutron-multiplication measurements

    Energy Technology Data Exchange (ETDEWEB)

    Zolnay, A.S.; Barnett, C.S.; Spracklen, H.P.

    1982-10-14

    We have developed an instrument to measure neutron multiplication by statistical analysis of the timing of neutrons emitted from fissionable material. This instrument is capable of repeated analysis of the same recorded data with selected algorithms, graphical displays showing statistical properties of the data, and preservation of raw data on disk for future comparisons. In our measurements we have made a comparison of the covariance to mean and Feynman variance to mean analysis algorithms to show that the covariance avoids a bias term and measures directly the effect due to the presence of neutron chains. A spherical assembly of enriched uranium shells and acrylic resin reflector/moderator components used for the measurements is described. Preliminary experimental results of the Feynman variance to mean measurements show the expected correlation with assembly multiplication.

  2. Design of a fuzzy logic based controller for neutron power regulation; Diseno de un controlador basado en logica difusa para la regulacion de flujo neutronico

    Energy Technology Data Exchange (ETDEWEB)

    Velez D, D

    2000-07-01

    This work presents a fuzzy logic controller design for neutron power control, from its source to its full power level, applied to a nuclear reactor model. First, we present the basic definitions on fuzzy sets as generalized definitions of the crisp (non fuzzy) set theory. Likewise, we define the basic operations on fuzzy sets (complement, union, and intersection), and the operations on fuzzy relations such as projection and cylindrical extension operations. Furthermore, some concepts of the fuzzy control theory, such as the main modules of the typical fuzzy controller structure and its internal variables, are defined. After the knowledge base is obtained by simulation of the reactor behavior, where the controlled system is modeled by a simple nonlinear reactor model, this model is used to infer a set of fuzzy rules for the reactor response to different insertions of reactivity. The reduction of the response time, using fuzzy rule based controllers on this reactor, is possible by adjusting the output membership functions, by selecting fuzzy rule sets, or by increasing the number of crisp inputs to the fuzzy controller. System characteristics, such as number of rules, response times, and safety parameter values, were considered in the evaluation of each controller merits. Different fuzzy controllers are designed to attain the desired power level, to maintain a constant level for long periods of time, and to keep the reactor away from a shutdown condition. The basic differences among the controllers are the number of crisp inputs and the novel implementation of a crisp power level-based selection of different sets of output membership functions. Simulation results highlight, mainly: (1) A decrease of the response variations at low power level, and (2) a decrease in the time required to attain the desired neutron power. Finally, we present a comparative study of different fuzzy control algorithms applied to a nuclear model. (Author)

  3. La Comprensión Narrativa en Edad Preescolar: Un Instrumento para su Medición Narrative Comprehension in the Preschool Age: An Assessment Instrument

    OpenAIRE

    Katherine Strasser; Antonia Larraín; Soledad López de Lérida; María Rosa Lissi

    2010-01-01

    La comprensión narrativa es una habilidad fundamental en la alfabetización infantil, poco atendida por investigadores y educadores por las dificultades para comprenderla y medirla, sobre todo a edades tempranas. Se reportan resultados de un estudio cuyo objetivo fue elaborar y validar un instrumento para la medición de la comprensión narrativa en niños en edad preescolar. Participaron 117 niños y niñas chilenos entre 3 años 6 meses y 5 años 1 mes de edad, pertenecientes a jardines infantiles ...

  4. Desenvolvimento de um instrumento para avaliar a movimentação e transferência de clientes: um enfoque ergonômico Desarrolo de un aparato para evaluar la movimentación y transferencia de clientes: enfoque ergonomico Development of an instrument for assessing patient handling task: an ergonomic approach

    Directory of Open Access Journals (Sweden)

    Cremilde Aparecida Trindade Radovanovic

    2002-09-01

    Full Text Available Os distúrbios osteomusculares relacionados ao trabalho, particularmente a dor e as lesões na região lombar, representam um risco para os trabalhadores de enfermagem. Esses profissionais são especialmente suscetíveis a problemas vertebrais pelo fato de terem que movimentar e transportar pacientes regularmente. O objetivo desta pesquisa foi descrever o desenvolvimento de um instrumento para avaliar os riscos ergonômicos durante os procedimentos de movimentação e transferência de clientes. Para ser desenvolvido teve como referencial teórico a ergonomia, o que abrange a interação entre os equipamentos, as atividades, o ambiente e o próprio trabalhador.Los disturbios osteomusculares relacionados al trabajo, particularmente al dolor y lesiones en la región lombar, representam risco para los trabajadores de enfermeria. Esos profissionales son especialmente suscetibles a problemas vertebrales por el hecho de tener que mobilizar y trasporta regularmente a .los clientes. El objetivo de este estudio es descrevir el desarrollo de un aparato para evaluar los riscos ergonomicos durante el procedimiento de movimentación y transferencia de clientes. Para su desarrollo tuvimos como referencial teorico la ergonomia la que engloba la interación entre los equipamientos, las actividades, el ambiente y el proprio trabajador.Nursing personnel are at a high risk from work-related musculoskeletal disorders, especially back symptoms. Handling patients has been attributed as one of the factors playing an important role in the aetiology of occupational low back pain. The aim of the study was to construct an instrument to evaluate the ergonomic risks during patient-handling tasks. The instrument was developed with an ergonomic approach involving the equipment, the tasks, the environment and the personnel.

  5. Powder neutron diffractometers HRPT and DMCG

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, P.; Doenni, A.; Staub, U.; Zolliker, M. [Lab. for Neutron Scattering ETH Zurich, Zurich (Switzerland) and Paul Scherrer Institute, Villigen (Switzerland)

    1996-11-01

    Basic properties and applications of SINQ powder neutron diffractometers are described. For optimum use of the continuous neutron beams these instruments are equipped with position sensitive detectors, and both high-intensity and high-resolution modes of operation are possible. HRPT attaining resolutions {delta}d/d{<=}10{sup -3}, d=lattice spacing, at a thermal neutron channel of the target station and DMCG at a cold neutron guide coated with m=2 supermirrors, are complementary concerning the applications: the former will be mainly used for structural studies and the latter to investigate magnetic ordering phenomena. (author) figs., tabs., refs.

  6. Neutron applications in materials for energy

    CERN Document Server

    Kearley, Gordon J

    2015-01-01

    Neutron Applications in Materials for Energy collects results and conclusions of recent neutron-based investigations of materials that are important in the development of sustainable energy. Chapters are authored by leading scientists with hands-on experience in the field, providing overviews, recent highlights, and case-studies to illustrate the applicability of one or more neutron-based techniques of analysis. The theme follows energy production, storage, and use, but each chapter, or section, can also be read independently, with basic theory and instrumentation for neutron scattering being

  7. Basic Design of the Cold Neutron Research Facility in HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hark Rho; Lee, K. H.; Kim, Y. K. (and others)

    2005-09-15

    The HANARO Cold Neutron Research Facility (CNRF) Project has been embarked in July 2003. The CNRF project has selected as one of the radiation technology development project by National Science and Technology Committee in June 2002. In this report, the output of the second project year is summarized as a basic design of cold neutron source and related systems, neutron guide, and neutron scattering instruments.

  8. Capturing the Future: Direct and Indirect Probes of Neutron Capture

    Energy Technology Data Exchange (ETDEWEB)

    Couture, Aaron Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-31

    This report documents aspects of direct and indirect neutron capture. The importance of neutron capture rates and methods to determine them are presented. The following conclusions are drawn: direct neutron capture measurements remain a backbone of experimental study; work is being done to take increased advantage of indirect methods for neutron capture; both instrumentation and facilities are making new measurements possible; more work is needed on the nuclear theory side to understand what is needed furthest from stability.

  9. Instrumental neutron activation analysis (INAA) in gemmology

    Energy Technology Data Exchange (ETDEWEB)

    Moauro, A. [ENEA, Casaccia (Italy); Burelli, F. [Control and Research Laboratory, Bastia (France)

    1995-01-01

    INAA is a multielementary analytical technique that allows the determination of about 30 elements (in many cases with very high sensitivity), without dissolving the sample and avoiding contamination by reagents and glassware. (authors). 6 refs., 1 fig., 2 tabs.

  10. Investigation of propagation algorithms for ray-tracing simulation of polarized neutrons

    DEFF Research Database (Denmark)

    Bergbäck Knudsen, Erik; Tranum-Rømer, A.; Willendrup, Peter Kjær

    2014-01-01

    Ray-tracing of polarized neutrons faces a challenge when the neutron propagates through an inhomogeneous magnetic field. This affects simulations of novel instruments using encoding of energy or angle into the neutron spin. We here present a new implementation of propagation of polarized neutrons...

  11. Proposal of requirements for performance in Brazil for systems of external individual monitoring for neutrons applying the TLD-albedo technique; Proposta de requisitos de desempenho no Brasil para sistemas de monitoracao individual externa para neutrons empregando a tecnica TLD-albedo

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Marcelo M.; Mauricio, Claudia L.P.; Pereira, Walsan W.; Fonseca, Evaldo S. da, E-mail: marcelo@ird.gov.b, E-mail: claudia@ird.gov.b, E-mail: walsan@ird.gov.b, E-mail: evaldo@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Silva, Ademir X., E-mail: ademir@con.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil).

    2009-07-01

    This work presents a criteria and conditions proposal for the regulations in Brazil of individual monitoring systems for neutrons applying the albedo technique with thermoluminescent detectors. Tests are proposed for the characterization performance of the system based on the Regulation ISO 21909 and on the experience of the authors

  12. Conceptual moderator studies for the Spallation Neutron Source short-pulse second target station

    Science.gov (United States)

    Gallmeier, F. X.; Lu, W.; Riemer, B. W.; Zhao, J. K.; Herwig, K. W.; Robertson, J. L.

    2016-06-01

    Candidate moderator configurations for a short-pulse second target station (STS) at the Oak Ridge National Laboratory Spallation Neutron Source (SNS) have been identified using a global optimizer framework built around the MCNPX particle transport code. Neutron brightness metrics were selected as the figure-of-merit. We assumed that STS would use one out of six proton pulses produced by an SNS accelerator upgraded to operate at 1.3 GeV proton energy, 2.8 MW power and 60 Hz repetition rate. The simulations indicate that the peak brightness can be increased by a factor of 5 and 2.5 on a per proton pulse basis compared to the SNS first target station for both coupled and decoupled para-hydrogen moderators, respectively. Additional increases by factors of 3 and 2 were demonstrated for coupled and decoupled moderators, respectively, by reducing the area of neutron emission from 100 × 100 mm2 to 20 × 20 mm2. This increase in brightness has the potential to translate to an increase of beam intensity at the instruments' sample positions even though the total neutron emission of the smaller moderator is less than that of the larger. This is especially true for instruments with small samples (beam dimensions). The increased fluxes in the STS moderators come at accelerated poison and de-coupler burnout and higher radiation-induced material damage rates per unit power, which overall translate into lower moderator lifetimes. A first effort was undertaken to group decoupled moderators into a cluster collectively positioning them at the peak neutron production zone in the target and having a three-port neutron emission scheme that complements that of a cylindrical coupled moderator.

  13. Conceptual moderator studies for the Spallation Neutron Source short-pulse second target station.

    Science.gov (United States)

    Gallmeier, F X; Lu, W; Riemer, B W; Zhao, J K; Herwig, K W; Robertson, J L

    2016-06-01

    Candidate moderator configurations for a short-pulse second target station (STS) at the Oak Ridge National Laboratory Spallation Neutron Source (SNS) have been identified using a global optimizer framework built around the MCNPX particle transport code. Neutron brightness metrics were selected as the figure-of-merit. We assumed that STS would use one out of six proton pulses produced by an SNS accelerator upgraded to operate at 1.3 GeV proton energy, 2.8 MW power and 60 Hz repetition rate. The simulations indicate that the peak brightness can be increased by a factor of 5 and 2.5 on a per proton pulse basis compared to the SNS first target station for both coupled and decoupled para-hydrogen moderators, respectively. Additional increases by factors of 3 and 2 were demonstrated for coupled and decoupled moderators, respectively, by reducing the area of neutron emission from 100 × 100 mm(2) to 20 × 20 mm(2). This increase in brightness has the potential to translate to an increase of beam intensity at the instruments' sample positions even though the total neutron emission of the smaller moderator is less than that of the larger. This is especially true for instruments with small samples (beam dimensions). The increased fluxes in the STS moderators come at accelerated poison and de-coupler burnout and higher radiation-induced material damage rates per unit power, which overall translate into lower moderator lifetimes. A first effort was undertaken to group decoupled moderators into a cluster collectively positioning them at the peak neutron production zone in the target and having a three-port neutron emission scheme that complements that of a cylindrical coupled moderator.

  14. Desarrollo instrumental y de metodología analítica para el análisis directo de sólidos mediante LIBS

    OpenAIRE

    Álvarez Llamas, César

    2012-01-01

    El objetivo del presente trabajo consiste en el desarrollo y optimización de un sistema experimental LIBS (Laser-Induced Breakdown Spectroscopy), y en su aplicación para el análisis directo de muestras sólidas.

  15. Polarized neutrons for Australian scientific research

    Science.gov (United States)

    Kennedy, Shane J.

    2005-02-01

    Polarized neutron scattering has been a feature at ANSTO's HIFAR research reactor since the first polarization analysis (PA) spectrometer Longpol began operation over 30 years ago. Since that time, we have improved performance of Longpol and added new capabilities in several reincarnations of the instrument. Most of the polarized neutron experiments have been in the fields of magnetism and superconductivity, and most of that research has involved PA. Now as we plan our next generation neutron beam facility, at the Replacement Research Reactor (RRR), we intend to continue the tradition of PA but with a far broader scope in mind. Our new capabilities will combine PA and energy analysis with both cold and thermal neutron source spectra. We will also provide capabilities for research with polarized neutrons in small-angle neutron scattering and in neutron reflectometry. The discussion includes a brief historical account of the technical developments with a summary of past and present applications of polarized neutrons at HIFAR, and an outline of the polarized neutron capabilities that will be included in the first suite of instruments, which will begin operation at the new reactor in 2006.

  16. The effects of nuclear power generators upon electronic instrumentation

    Science.gov (United States)

    Miller, C. G.; Truscello, V. C.

    1970-01-01

    Radiation sensitivity of electronic instruments susceptible to neutron and gamma radiation is evaluated by means of a radioisotope thermoelectric generator /RTG/. The gamma field of the RTG affects instrument operation and requires shielding, the neutron field does not affect operation via secondary capture-gamma production.

  17. Adaptação de instrumento para dimensionar horas diárias de assistência de enfermagem residencial Adaptacion de instrumento para medir horas diarias de atención de enfermería domiciliaria Adaptation of an instrument for the measurement of daily hours for nursing care at patient's home

    Directory of Open Access Journals (Sweden)

    Luiza Watanabe Dal Ben

    2004-03-01

    Full Text Available O Therapeutic Intervention Scoring System Intermediate: TISS-Intermediário foi traduzido para a língua portuguesa e adaptado para estabelecer horas diárias de assistência domiciliar. O processo de modificação do instrumento, desenvolvido através da Técnica Delphi, teve como participantes 16 enfermeiros, que atuam em empresas de assistência domiciliar e determinam horas diárias de assistência de enfermagem para pacientes na residência, após a hospitalização. Ao término do estudo obteve-se um instrumento com 104 itens, para ser no futuro validado clinicamente. Tal instrumento ajudará enfermeiros a estender cuidados de enfermagem a pacientes em casa, após a alta hospitalar, especialmente na tomada de decisões relativas à avaliação dos pacientes.El Therapeutic Intervention Scoring System Intermediate: TISS-Intermedio, fue traducido para el idioma portugués y adaptado para establecer las horas diarias de asistencia en el domicilio. Dieciséis enfermeros participaron del proceso de modificación del instrumento desarrollado a través de la Técnica Delphi. Esos enfermeros actúan en empresas de atención a domicilio y determinan las horas diarias de atención de enfermería a los pacientes en su domicilio después del alta. Al término del estudio se obtuvo un instrumento con 104 items para ser validado clínicamente.Tal instrumento ayudará a los enfermeros a extender sus cuidados de enfermería a pacientes que se encuentran en casa, después del alta hospitalario, especialmente en la toma de decisiones relacionadas con la evaluación de los pacientes.The Therapeutic Intervention Scoring System Intermediate: TISS-Intermediate, was translated into Portuguese and adapted to establish the number of hours daily of home care. The adaptation process of the instrument, developed with the Delphi Technique, used 16 nurses, who work in home care service providers and helped in calculating the number of nursing care hours for patients at

  18. (International Collaboration on Advanced Neutron Sources)

    Energy Technology Data Exchange (ETDEWEB)

    Hayter, J.B.

    1990-11-08

    The International Collaboration on Advanced Neutron Sources was started about a decade ago with the purpose of sharing information throughout the global neutron community. The collaboration has been extremely successful in optimizing the use of resources, and the discussions are open and detailed, with reasons for failure shared as well as reasons for success. Although the meetings have become increasingly oriented toward pulsed neutron sources, many of the neutron instrumentation techniques, such as the development of better monochromators, fast response detectors and various data analysis methods, are highly relevant to the Advanced Neutron Source (ANS). I presented one paper on the ANS, and another on the neutron optical polarizer design work which won a 1989 R D-100 Award. I also gained some valuable design ideas, in particular for the ANS hot source, in discussions with individual researchers from Canada, Western Europe, and Japan.

  19. (International Collaboration on Advanced Neutron Sources)

    Energy Technology Data Exchange (ETDEWEB)

    Hayter, J.B.

    1990-11-08

    The International Collaboration on Advanced Neutron Sources was started about a decade ago with the purpose of sharing information throughout the global neutron community. The collaboration has been extremely successful in optimizing the use of resources, and the discussions are open and detailed, with reasons for failure shared as well as reasons for success. Although the meetings have become increasingly oriented toward pulsed neutron sources, many of the neutron instrumentation techniques, such as the development of better monochromators, fast response detectors and various data analysis methods, are highly relevant to the Advanced Neutron Source (ANS). I presented one paper on the ANS, and another on the neutron optical polarizer design work which won a 1989 R D-100 Award. I also gained some valuable design ideas, in particular for the ANS hot source, in discussions with individual researchers from Canada, Western Europe, and Japan.

  20. Prediction analysis of dose equivalent responses of neutron dosemeters used at a MOX fuel facility.

    Science.gov (United States)

    Tsujimura, N; Yoshida, T; Takada, C

    2011-07-01

    To predict how accurately neutron dosemeters can measure the neutron dose equivalent (rate) in MOX fuel fabrication facility work environments, the dose equivalent responses of neutron dosemeters were calculated by the spectral folding method. The dosemeters selected included two types of personal dosemeter, namely a thermoluminescent albedo neutron dosemeter and an electronic neutron dosemeter, three moderator-based neutron survey meters, and one special instrument called an H(p)(10) monitor. The calculations revealed the energy dependences of the responses expected within the entire range of neutron spectral variations observed in neutron fields at workplaces.

  1. SERVQUAL x SERVPERF: comparação entre instrumentos para avaliação da qualidade de serviços internos SERVQUAL versus SERVPERF: a comparison of instruments for assessing internal service quality

    Directory of Open Access Journals (Sweden)

    Gilberto Gabriel Eid Salomi

    2005-08-01

    Full Text Available Nos últimos anos, diversos trabalhos têm considerado a importância da mensuração da qualidade por clientes externos às organizações. No entanto, qualquer organização industrial, não prescinde da avaliação de desempenho dos serviços internos como um meio para a melhoria contínua dos seus processos. Por isso, algumas pesquisas têm sugerido a utilização de instrumentos geralmente utilizados para mensuração da qualidade por clientes externos na avaliação de serviços internos. Nesse sentido, esse trabalho consiste na comparação de dois instrumentos, SERVPERF e SERVQUAL e suas variantes com ponderação, resultando em quatro instrumentos. No trabalho apresenta-se a aplicação destes instrumentos de qualidade de serviços na mensuração da qualidade de serviços internos em uma empresa do ramo industrial mecânico. Considera-se o serviço interno do departamento de manutenção industrial prestado às diversas células de manufatura em uma empresa fabricante de ferramentas industriais, profissionais e instrumentos de medição. Para a coleta dos dados foram aplicados questionários para os usuários dos serviços de manutenção e seus resultados foram analisados estatisticamente. O trabalho aponta que os valores obtidos para os instrumentos estudados são próximos entre si e comparáveis aos resultados da literatura. O artigo conclui também que o uso dos instrumentos SERVPERF e SERVQUAL para medida de qualidade do serviço de manutenção da empresa estudada foi viável, não havendo restrições quanto aos estimadores de confiabilidade e validade.Over the years, a number of papers have discussed the importance of measuring service quality based on the assessment of external customers. However, industrial organizations should also consider internal service performance evaluations as a means to achieve continuous process improvement. Therefore, researchers have suggested that the quality of internal services in industrial

  2. National phantoms bank for the service of nuclear medicine in Cuba. Utility for the quality control of the instrumentation; Banco de fantomas nacional para los servicios de medicina nuclear en Cuba. Utilidad para el control de calidad de la instrumentacion

    Energy Technology Data Exchange (ETDEWEB)

    Varela C, C.; Diaz B, M. [CCEEM, Calle 4 No. 455 (altos) e/19 y 21, Vedado, Ciudad Habana (Cuba); Lopez B, G.M. [CPHR, Calle 20 No. 4113 e/41 y 47, Playa Ciudad Habana (Cuba)]. e-mail: consuelo.varela@infomed.sld.cu

    2006-07-01

    Although, most of the applications in Nuclear Medicine have diagnostic ends, its going enlarging considerably the therapeutic applications. So that the diagnostic accuracy or the therapy effectiveness have not been affected, it becomes indispensable the quality control of the instrumentation, independently of its technological complexity and/or its exploitation period. Before the real lack of phantoms in the institutions, it was created a bank that puts to disposition of all the institutions, the existent phantoms in the country, and those that are going acquired, centralized by the State Control of Medical Equipment Center (CCEEM) and with Web access in its place www.eqmed.sld.cu. Having like base the elaboration of the National Protocol for the Quality Control of the Instrumentation in Nuclear Medicine that keeps in mind the international normative and the own existent conditions, were dictated and established two national regulations and its are being carried out the first audits to the instrumentation quality. These have evidenced the partial realization of the established quality controls in the services, the necessity to make aware as for the fulfillment of the criteria and quality concepts for the instrumentation, as well as the necessity to increase the phantoms number to the bank to guarantee the fulfillment of the Quality Control Programs. (Author)

  3. Neutron activation analysis of alternative phosphate rocks used in animal nutrition; Analise por ativacao neutronica por fontes alternativas de fosforo para a nutricao animal

    Energy Technology Data Exchange (ETDEWEB)

    Canella, Artur A.; Ferreira, Walter M. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Escola de Veterinaria]. E-mail: avelara@ufmg.br; Menezes, Maria Angela de B.C. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)]. E-mail: menezes@cdtn.br

    2005-07-01

    Since 1980's, Bovine Sponghiform Encephalophaty has insidiously created a fierce battleground between farmers, scientists, environmentalists and consumers. The use of meat and bone meals is currently prohibited in ruminant feeds throughout the world. Some inorganic sources offer the combination of high phosphorus content and acceptable animal digestibility make them options as supplemental phosphorus, for instance phosphate rocks, general term applied to minerals valued chiefly for their phosphorus content. However, phosphate rocks are long been known containing hazardous elements, make them sometimes unsuitable for animal nutrition. Neutron Activation Analysis has been supportive to the mineral evaluation of alternative phosphate rocks. This evaluation is subject of on-going doctoral thesis which has been carried-out by the main author. The NAA method has been very efficient due to its highly sensitive and multi-elemental nature. In this paper results of Vanadium content from three different phosphate rocks are presented. Their values have been pointed out that Brazilian phosphate rocks present hazardous elements at the same levels of phosphate rocks from some countries of Africa, North America and Middle East, data from our study (Brazilian data) and FAO - Food and Agriculture Organization (others countries). (author)

  4. Development of neutronic models with KANEXT for a reactor of traveling wave; Desarrollo de modelos neutronicos con KANEXT para un reactor de onda viajera

    Energy Technology Data Exchange (ETDEWEB)

    Lopez S, R. C.; Francois L, J. L. [UNAM, Facultad de Ingeniera, Departamento de Sistemas Energeticos, Paseo Cuauhnahuac No. 8532, Col. Progreso, 62550 Jiutepec, Morelos (Mexico); Becker, M., E-mail: rcarlosls@yahoo.com.mx [Institut fur Neutronenphysik und Reaktortechnik (KIT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany)

    2012-10-15

    Problems with the computation time in a based code on the Monte Carlo method, they conduct to explore the option of the deterministic codes to be able to develop a model of robust reactor of traveling wave, and where short term results are obtained to carry out experimentation work to the moment to study an assemblies exchange scheme as method of fuel administration. KANEXT is a versatile and reliable code, developed in Germany that has satisfied our development necessities until the moment. In this article is described the KANEXT operation, and like it was implemented to develop a preliminary model of reactor core of traveling wave with operation way of stationary wave. The results obtained until the moment, as for the neutrons multiplication factor and the isotopic balance, are encouraging and they lead to refine the model removing completely the axial covering. The adoption of deterministic codes has allowed carrying out tests of complete core in a conventional computer in question of only hours; this will be valuable in the next stage of the research, where developing a re situate scheme of fuel assemblies will involve a great quantity of sprints. (Author)

  5. Romeo y Julieta : diez piezas para piano Op. 75 un acercamiento al color armónico e instrumental en Prokofiev

    OpenAIRE

    Sánchez Uribe, David

    2010-01-01

    Romeo y Julieta: Diez piezas para piano Op.75 es una suite compuesta por Prokofiev con extractos de su ballet Op.64 (1935), del que además realizó dos suites para orquesta. El régimen estalinista, que se extendió también a las artes, tuvo influencia en el lenguaje neoclásico en el que está escrita la obra, caracterizado por una búsqueda de claridad melódica y tonal, que fuese accesible al público en general. Durante el texto se harán consideraciones estéticas que relacionen el argumento con e...

  6. Applications of neutron scattering to heterogeneous catalysis

    Science.gov (United States)

    Parker, Stewart F.; Lennon, David

    2016-09-01

    Historically, most studies of heterogeneous catalysts that have used neutron vibrational spectroscopy have employed indirect geometry instruments with a low (methane to synthesis gas (CO + H2) over Ni/Al2O3 catalysts and an operando study of CO oxidation. We conclude with a proposal for a unique instrument that combines both indirect and direct geometry spectrometers.

  7. Determination of the zero in the Two theta angle and the wavelength in the neutron diffractometer for the Cyber computer of the ININ and for the IBM compatible microcomputers; Determinacion del cero en el angulo Dos teta y la longitud de onda en el difractometro de neutrones para la computadora Cyber del ININ y para microcomputadoras compatibles con IBM

    Energy Technology Data Exchange (ETDEWEB)

    Macias B, L.R

    1991-05-15

    The objective of this work consists on determining the calibration in the angular parameters and the neutron wavelength used in the neutron diffractometer of the TRIGA Mark III reactor, through some readings in that a well-known sample is used by means of a Fortran computer program that is used in the CYBER computer of the ININ in Mexico, and/or in micro computers compatible with IBM. The program was also designed to determine the zero of the 2 {theta} angle of the goniometer of the diffractometer. The generated data were proven by means of well-known data of the Powder Diffraction File of the Joint Committee on Powder Diffraction Standards (JCPDS). (Author)

  8. Radioisotope instruments

    CERN Document Server

    Cameron, J F; Silverleaf, D J

    1971-01-01

    International Series of Monographs in Nuclear Energy, Volume 107: Radioisotope Instruments, Part 1 focuses on the design and applications of instruments based on the radiation released by radioactive substances. The book first offers information on the physical basis of radioisotope instruments; technical and economic advantages of radioisotope instruments; and radiation hazard. The manuscript then discusses commercial radioisotope instruments, including radiation sources and detectors, computing and control units, and measuring heads. The text describes the applications of radioisotop

  9. Neutron Repulsion

    CERN Document Server

    Manuel, Oliver K

    2011-01-01

    Earth is connected gravitationally, magnetically and electrically to its heat source - a neutron star that is obscured from view by waste products in the photosphere. Neutron repulsion is like the hot filament in an incandescent light bulb. Excited neutrons are emitted from the solar core and decay into hydrogen that glows in the photosphere like a frosted light bulb. Neutron repulsion was recognized in nuclear rest mass data in 2000 as the overlooked source of energy, the keystone of an arch that locked together these puzzling space-age observations: 1.) Excess 136Xe accompanied primordial helium in the stellar debris that formed the solar system (Fig. 1); 2.) The Sun formed on the supernova core (Fig. 2); 3.) Waste products from the core pass through an iron-rich mantle, selectively carrying lighter elements and lighter isotopes of each element into the photosphere (Figs. 3-4); and 4.) Neutron repulsion powers the Sun and sustains life (Figs. 5-7). Together these findings offer a framework for understanding...

  10. German neutron scattering conference. Programme and abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Brueckel, Thomas (ed.)

    2012-07-01

    The German Neutron Scattering Conference 2012 - Deutsche Neutronenstreutagung DN 2012 offers a forum for the presentation and critical discussion of recent results obtained with neutron scattering and complementary techniques. The meeting is organized on behalf of the German Committee for Research with Neutrons - Komitee Forschung mit Neutronen KFN - by the Juelich Centre for Neutron Science JCNS of Forschungszentrum Juelich GmbH. In between the large European and international neutron scattering conferences ECNS (2011 in Prague) and ICNS (2013 in Edinburgh), it offers the vibrant German and international neutron community an opportunity to debate topical issues in a stimulating atmosphere. Originating from ''BMBF Verbundtreffen'' - meetings for projects funded by the German Federal Ministry of Education and Research - this conference series has a strong tradition of providing a forum for the discussion of collaborative research projects and future developments in the field of research with neutrons in general. Neutron scattering, by its very nature, is used as a powerful probe in many different disciplines and areas, from particle and condensed matter physics through to chemistry, biology, materials sciences, engineering sciences, right up to geology and cultural heritage; the German Neutron Scattering Conference thus provides a unique chance for exploring interdisciplinary research opportunities. It also serves as a showcase for recent method and instrument developments and to inform users of new advances at neutron facilities.

  11. Neutron scattering for the analysis of biological structures. Brookhaven symposia in biology. Number 27

    Energy Technology Data Exchange (ETDEWEB)

    Schoenborn, B P [ed.

    1976-01-01

    Sessions were included on neutron scattering and biological structure analysis, protein crystallography, neutron scattering from oriented systems, solution scattering, preparation of deuterated specimens, inelastic scattering, data analysis, experimental techniques, and instrumentation. Separate entries were made for the individual papers.

  12. The neutron reflectometer at `SINQ`

    Energy Technology Data Exchange (ETDEWEB)

    Clemens, D. [Lab. for Neutron Scattering ETH Zurich, Zurich (Switzerland) and Paul Scherrer Institute, Villigen (Switzerland)

    1996-11-01

    SINQ`s dedicated reflectometer will be a flexible instrument in many respect. A `white beam time of flight` as well as a `constant wavelength` setup are possible for reflectometric experiments in a vertical scattering geometry. The phase controlled double chopper at the beginning of the instrument together with properly chosen time channels at the detector allow for the variation of the temporal resolution. Collimation slits serve to determine the angular resolution. In combination, the resolution can be tailored to the experimental needs. Additionally, one can adjust the illumination of the sample by setting the sample table and the detector to an appropriate distance. A mounting for exchangeable mirrors can be used to supply polarized neutrons by a multilayer polarizer or monochromatic neutrons by a multilayer monochromator. When it is equipped with a supermirror as a deflecting unit one can maintain a horizontal sample position which makes reflectometry on liquid samples practicable. Remanent polarizers are assigned for the changing over of the neutron polarization. A 1 T electromagnet installed on the sample manipulation table and polarization analyzers complete the polarized reflectometry setup. Alternately, an x-y-detector and single detectors will be available. By 1997/1998 the neutron reflectometer will be operational as a users` instrument. (author) 9 figs., 2 tabs., 30 refs.

  13. Desarrollo de un instrumento para evaluar la dieta en niños y adolescentes colombianos Developing an instrument to evaluate diet in children and adolescents in Colombia

    Directory of Open Access Journals (Sweden)

    María Fernanda Ardila

    2012-12-01

    Full Text Available OBJETIVOS: desarrollar un cuestionario de frecuencia de consumo, útil en la investigación epidemiológica de las relaciones dieta-cáncer, dieta-enfermedad cardiovascular y dieta-estado de nutrición, en niños y adolescentes. MÉTODOS: sesenta y dos sujetos entre 10 y 20 años de edad, respondieron un recordatorio del consumo de las últimas 24 horas, utilizando el método Max_r se seleccionaron alimentos con poder discriminante para estimar el consumo de 12 nutrientes relacionados con las enfermedades crónicas. RESULTADOS: el cuestionario tiene dos secciones en ellas se indaga por la frecuencia de consumo con nueve categorías. Un total de 22 alimentos hacen parte de la lista de chequeo de la primera sección. Un total de 43 ítems hacen parte de la segunda sección donde se indaga por prácticas y hábitos alimentarios de interés para la salud pública. Todos los coeficientes r alcanzados para los nutrientes de interés estuvieron por encima de 0,90 - mínimo 0,94, máximo 1,0. El mínimo fue para el ácido fólico, el máximo para la grasa total, la grasa poli insaturada y la vitamina A (UI. CONCLUSIONS: el diseño de este cuestionario permitirá la realización de estudios epidemiológicos para explorar las relaciones dieta-cáncer, dieta-enfermedad cardiovascular y dieta-estado de nutrición. Además, facilitará el diseño, ejecución y evaluación de intervenciones individuales y poblacionales.OBJECTIVES: to develop a food frequency questionnaire useful in the epidemiological investigation of the relationships, diet-cancer, die-cardiovascular disease, and diet-nutritional status in children and adolescents. METHODS: sixty-two subjects between 10 and 20 years old answered a recall of intake of the last 24 hours. Using the method Max_r foods were selected to estimate intake of 12 nutrients, with discriminating power, related to chronic diseases. RESULTS: the questionnaire has two sections. They inquire about the frequency of

  14. La TV como medio de educación moral para la ciudadanía democrática TV as an instrument of moral education for democratic citizenship

    Directory of Open Access Journals (Sweden)

    Antonio Linde Navas

    2008-10-01

    Full Text Available Pocos campos como el de los contenidos de la televisión suministran hoy día un material más controvertido e interesante desde un punto de vista moral. Al presentarnos casos de conflictos de valores y derechos, la TV ofrece muchas oportunidades para la reflexión moral. Se trata de un material estimable, con problemas relevantes y actuales, inteligibles y motivadores para los jóvenes. En este trabajo se hacen sugerencias para utilizar didácticamente algunos contenidos de la TV. Más concretamente, se intenta mostrar las posibilidades que tienen los dilemas morales. Se exponen varios dilemas construidos a partir de contenidos televisivos, así como indicaciones para su uso educativo y algún trabajo de campo sobre los mismos. Few means provide us with more controversial and interesting materials in a moral sense than television contents do nowadays. By showing many cases which involve a conflict of rights and values, it gives plenty of opportunities for moral reflection. It is a very valuable instrument since it offers us relevant present problems, which are also very easy to understand and motivating for young people. This paper is intended to make some suggestions in order to foster the didactic use of some television contents. More specifically, it is intended to show the possibilities that moral dilemmas offer for this purpose. Accordingly, I will put forward some dilemmas which have been built from television materials, as well as several indications for its didactic use and a field research example about them.

  15. Forming images with thermal neutrons

    Science.gov (United States)

    Vanier, Peter E.; Forman, Leon

    2003-01-01

    Thermal neutrons passing through air have scattering lengths of about 20 meters. At further distances, the majority of neutrons emanating from a moderated source will scatter multiple times in the air before being detected, and will not retain information about the location of the source, except that their density will fall off somewhat faster than 1/r2. However, there remains a significant fraction of the neutrons that will travel 20 meters or more without scattering and can be used to create an image of the source. A few years ago, a proof-of-principle "camera" was demonstrated that could produce images of a scene containing sources of thermalized neutrons and could locate a source comparable in strength with an improvised nuclear device at ranges over 60 meters. The instrument makes use of a coded aperture with a uniformly redundant array of openings, analogous to those used in x-ray and gamma cameras. The detector is a position-sensitive He-3 proportional chamber, originally used for neutron diffraction. A neutron camera has many features in common with those designed for non-focusable photons, as well as some important differences. Potential applications include detecting nuclear smuggling, locating non-metallic land mines, assaying nuclear waste, and surveying for health physics purposes.

  16. Neutron activation analysis of lichens for atmospheric pollution study in Sao Paulo city; Analise de liquens por ativacao neutronica para estudo da poluicao atmosferica da cidade de Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Fuga, Alessandra; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: alessandrafuga@yahoo.com.br; Marcelli, Marcelo P. [Instituto de Botanica, Sao Paulo, SP (Brazil). Secao de Micologia e Liquenologia]. E-mail: mpmarcelli@superig.com.br

    2005-07-01

    In the present study instrumental neutron activation analysis has been applied to determine the elements accumulated in samples of Canoparmelia texana, a specie of lichen, collected in regions with different levels of pollution: Intervales State Park, an area considered non polluted that belongs to Atlantic Forest ecosystem and distinct sites in the metropolitan region of Sao Paulo city. The results obtained in the analysis showed that samples collected in the clean area indicated lower concentrations of elements than those obtained for samples from metropolitan region. The concentrations of the elements Ba, Ca, Cl, Fe, K, Mn, Na, Rb and Zn were obtained at {mu}g g{sup -1} levels and the elements As, Br, Co, Cr, Cs, La, Sb, Sc, Se and U at ng g{sup -1} levels. Cluster analysis was applied to classify into distinct groups the sites using the element concentrations in these samples. The accuracy and precision of the results were evaluated by IAEA 336 Lichen reference material analysis and the data given for this material were in agreement with certified values with relative standard deviations lower than 11,4%. (author)

  17. Study of neutron spectrometers for ITER

    Energy Technology Data Exchange (ETDEWEB)

    Kaellne, Jan

    2005-11-15

    A review is presented of the developments in the field of neutron emission spectrometry (NES) which is of relevance for identifying the role of NES diagnostics on ITER and selecting suitable instrumentation. Neutron spectrometers will be part of the ITER neutron diagnostic complement and this study makes a special effort to examine which performance characteristics the spectrometers should possess to provide the best burning plasma diagnostic information together with neutron cameras and neutron yield monitors. The performance of NES diagnostics is coupled to how much interface space can be provided which has lead to an interest to find compact instruments and their NES capabilities. This study assesses all known spectrometer types of potential interest for ITER and makes a ranking of their performance (as demonstrated or projected), which, in turn, are compared with ITER measurement requirements as a reference; the ratio of diagnostic performance to interface cost for different spectrometers is also discussed for different spectrometer types. The overall result of the study is an assessment of which diagnostic functions neutron measurements can provide in burning plasma fusion experiments on ITER and the role that NES can play depending on the category of instrument installed. Of special note is the result that much higher quality diagnostic information can be obtained from neutron measurements with total yield monitors, profile flux cameras and spectrometers when the synergy in the data is considered in the analysis and interpretation.

  18. New Techniques in Neutron Scattering

    DEFF Research Database (Denmark)

    Birk, Jonas Okkels

    . The instrument is ideally suited for solid state experiments with extreme sample environments such as large pressures and strong magnetic fields. CAMEA combines the time-of-flight technique to determine the energy of the incoming neutrons with a complex multiplex backend that will analyse and detect......Neutron scattering is an important experimental technique in amongst others solid state physics, biophysics, and engineering. This year construction of European Spallation Source (ESS) was commenced in Lund, Sweeden. The facility will use a new long pulsed source principle to obtain higher...

  19. Challenges for maintaining the modernization of instrumentation and control systems; Desafios para el mantenimiento en la modernizacion de sistemas de instrumentacion y control

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, V.

    2014-04-01

    Instrumentation and control system upgrades in nuclear power plants come with some challenges for their maintenance staff. It is important to have a long term modernization plant that derives from specific studies for each system. Training, spares, configuration control and cybersecurity are critical topics to take into account from the beginning of these projects. New system maintenance plans can require a new approach in accordance with the technology. FPGAs (Field Programmable Gate Array) appear as the alternative for the future, mainly in safety systems. (Author)

  20. Utilidad de un sistema de seguimiento óptico de instrumental en cirugía laparoscópica para evaluación de destrezas motoras

    OpenAIRE

    Sánchez Margallo, Juan Alberto; Sánchez Margallo, Francisco Miguel; Pagador Carrasco, J.B.; Oropesa García, Ignacio; Gómez Aguilera, Enrique J.; Moreno del Pozo, Jose

    2013-01-01

    En este trabajo se estudia la utilidad de un sistema de evaluación de destrezas quirúrgicas basado en el análisis de los movimientos del instrumental laparoscópico. Método: El sistema consta de un simulador físico laparoscópico y un sistema de seguimiento y evaluación de habilidades técnicas quirúrgicas. En el estudio han participado 6 cirujanos con experiencia intermedia (entre 1 y 50 intervenciones laparoscópicas) y 5 cirujanos expertos (más de 50 intervenciones laparoscópicas), todos e...

  1. 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.

  2. The synchronous active neutron detection assay system

    Energy Technology Data Exchange (ETDEWEB)

    Pickrell, M.M.; Kendall, P.K.

    1994-08-01

    We have begun to develop a novel technique for active neutron assay of fissile material in spent nuclear fuel. This approach will exploit a 14-MeV neutron generator developed by Schlumberger. The technique, termed synchronous active neutron detection (SAND), follows a method used routinely in other branches of physics to detect very small signals in presence of large backgrounds. Synchronous detection instruments are widely available commercially and are termed ``lock-in`` amplifiers. We have implemented a digital lock-in amplifier in conjunction with the Schlumberger neutron generator to explore the possibility of synchronous detection with active neutrons. The Schlumberger system can operate at up to a 50% duty factor, in effect, a square wave of neutron yield. Results are preliminary but promising. The system is capable of resolving the fissile material contained in a small fraction of the fuel rods in a cold fuel assembly; it also appears resilient to background neutron interference. The interrogating neutrons appear to be non-thermal and penetrating. Work remains to fully explore relevant physics and optimize instrument design.

  3. Neutron Position Sensitive Detectors for the ESS

    CERN Document Server

    Kirstein, Oliver; Stefanescu, Irina; Etxegarai, Maddi; Anastasopoulos, Michail; Fissum, Kevin; Gulyachkina, Anna; Höglund, Carina; Imam, Mewlude; Kanaki, Kalliopi; Khaplanov, Anton; Kittelmann, Thomas; Kolya, Scott; Nilsson, Björn; Ortega, Luis; Pfeiffer, Dorothea; Piscitelli, Francesco; Ramos, Judith Freita; Robinson, Linda; Scherzinger, Julius

    2014-01-01

    The European Spallation Source (ESS) in Lund, Sweden will become the world's leading neutron source for the study of materials. The instruments are being selected from conceptual proposals submitted by groups from around Europe. These instruments present numerous challenges for detector technology in the absence of the availability of Helium-3, which is the default choice for detectors for instruments built until today and due to the extreme rates expected across the ESS instrument suite. Additionally a new generation of source requires a new generation of detector technologies to fully exploit the opportunities that this source provides. The detectors will be sourced from partners across Europe through numerous in-kind arrangements; a process that is somewhat novel for the neutron scattering community. This contribution presents briefly the current status of detectors for the ESS, and outlines the timeline to completion. For a conjectured instrument suite based upon instruments recommended for construction, ...

  4. Concepto, instrumentos y desafíos de la edu-comunicación para el cambio social Concept, instruments and challenges of media education for social change

    Directory of Open Access Journals (Sweden)

    Alejandro Barranquero Carretero

    2007-10-01

    Full Text Available Pese a su extensa tradición en otros contextos geográficos, el campo de la edu-comunicación para el cambio social es prácticamente desconocido en nuestro país, por lo que sigue siendo infrautilizado por parte de organizaciones y profesionales comprometidos con el desarrollo. El artículo ofrece una aproximación histórica al concepto y describe sucintamente algunas de sus principales metodologías, a fin de avanzar en la consolidación de la disciplina y potenciar estrategias para el contexto venidero. Despite its long tradition in other geographic contexts, the field of communication for social change is almost unknown in our country; therefore, there is a widespread ignorance of communication basics on the part of organizations and professionals committed to development. The following article offers a brief historical approach to this concept and describes its main methodologies, in order to help consolidate the discipline and to promote strategies for the future.

  5. Formación instrumental

    Directory of Open Access Journals (Sweden)

    Darío Zerrate

    2008-09-01

    Full Text Available Es el nombre dado al proyecto de investigación que un Grupo de docentes del Énfasis de Pedagogía Instrumental del Departamento de Educación Musical de la Facultad de BELLAS ARTES, propone para reflexionar sobre la Didáctica Instrumental

  6. Preliminary Analysis of the Multisphere Neutron Spectrometer

    Science.gov (United States)

    Goldhagen, P.; Kniss, T.; Wilson, J. W.; Singleterry, R. C.; Jones, I. W.; VanSteveninck, W.

    2003-01-01

    Crews working on present-day jet aircraft are a large occupationally exposed group with a relatively high average effective dose from galactic cosmic radiation. Crews of future high-speed commercial aircraft flying at higher altitudes would be even more exposed. To help reduce the significant uncertainties in calculations of such exposures, the Atmospheric Ionizing Radiation (AIR) Project, an international collaboration of 15 laboratories, made simultaneous radiation measurements with 14 instruments on five flights of a NASA ER-2 high-altitude aircraft. The primary AIR instrument was a highly sensitive extended-energy multisphere neutron spectrometer with lead and steel shells placed within the moderators of two of its 14 detectors to enhance response at high energies. Detector responses were calculated for neutrons and charged hadrons at energies up to 100 GeV using MCNPX. Neutron spectra were unfolded from the measured count rates using the new MAXED code. We have measured the cosmic-ray neutron spectrum (thermal to greater than 10 GeV), total neutron fluence rate, and neutron effective dose and dose equivalent rates and their dependence on altitude and geomagnetic cutoff. The measured cosmic-ray neutron spectra have almost no thermal neutrons, a large "evaporation" peak near 1 MeV and a second broad peak near 100 MeV which contributes about 69% of the neutron effective dose. At high altitude, geomagnetic latitude has very little effect on the shape of the spectrum, but it is the dominant variable affecting neutron fluence rate, which was 8 times higher at the northernmost measurement location than it was at the southernmost. The shape of the spectrum varied only slightly with altitude from 21 km down to 12 km (56 - 201 grams per square centimeter atmospheric depth), but was significantly different on the ground. In all cases, ambient dose equivalent was greater than effective dose for cosmic-ray neutrons.

  7. FRAX TM: un nuevo instrumento para calcular el riesgo absoluto de fracturas a 10 años FRAX TM: A new instrument for calculating 10-year absolute fracture risk

    Directory of Open Access Journals (Sweden)

    Haraldo Claus-Hermberg

    2009-10-01

    Full Text Available La eficacia de nuevos agentes farmacológicos para la prevención de fracturas osteoporóticas y la decisión de intervención con la misma finalidad en la práctica clínica han sido guiadas por la evaluación de la densitometría ósea (DMO. Sin embargo, reconociendo la naturaleza multifactorial de ese desenlace, recientemente se dio a conocer el calculador Fracture Risk Assessment Tool (FRAX™ que persiguiendo los mismos objetivos de modelos previos, integra y combina varios de esos factores ponderadamente para estimar el riesgo absoluto de fractura de cadera o un combinado de fracturas osteoporóticas para los siguientes 10 años. El mismo sería ajustable a cualquier país incorporando al modelo la incidencia de fractura de cadera y las expectativas de vida edad- y sexo-específicas para la población a que pertenece el individuo. Este instrumento es presentado como un nuevo paradigma para ayudar en la toma de decisiones terapéuticas, especialmente farmacológicas. En la presente revisión se discuten algunas de sus características, como ser: la pretendida aplicabilidad a poblaciones de distintos países, la conveniencia de utilizar el riesgo absoluto a 10 años para todo el espectro etario de interés y si la eficacia de los tratamientos farmacológicos para la prevención de fracturas óseas en pacientes osteoporóticos podrá comprobarse también en pacientes seleccionados para tratamiento en base a este modelo. Finalmente, se llama la atención sobre el hecho de que aún no están claramente determinados los umbrales de riesgo orientadores para la toma de decisiones, los que obviamente tendrán un relevante impacto en el número de pacientes pasibles de tratamiento.The efficacy of new pharmacological agents for the prevention of osteoporotic fractures and the clinical decision to intervene with that purpose in daily medical practice have been guided by the evaluation of bone mineral density (BMD. However, given the multifactorial

  8. Production and applications of neutrons using particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Chichester, David L. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2009-11-01

    Advances in neutron science have gone hand in hand with the development and of particle accelerators from the beginning of both fields of study. Early accelerator systems were developed simply to produce neutrons, allowing scientists to study their properties and how neutrons interact in matter, but people quickly realized that more tangible uses existed too. Today the diversity of applications for industrial accelerator-based neutron sources is high and so to is the actual number of instruments in daily use is high, and they serve important roles in the fields where they're used. This chapter presents a technical introduction to the different ways particle accelerators are used to produce neutrons, an historical overview of the early development of neutron-producing particle accelerators, a description of some current industrial accelerator systems, narratives of the fields where neutron-producing particle accelerators are used today, and comments on future trends in the industrial uses of neutron producing particle accelerators.

  9. PRODUCTION AND APPLICATIONS OF NEUTRONS USING PARTICLE ACCELERATORS

    Energy Technology Data Exchange (ETDEWEB)

    David L. Chichester

    2009-11-01

    Advances in neutron science have gone hand in hand with the development and of particle accelerators from the beginning of both fields of study. Early accelerator systems were developed simply to produce neutrons, allowing scientists to study their properties and how neutrons interact in matter, but people quickly realized that more tangible uses existed too. Today the diversity of applications for industrial accelerator-based neutron sources is high and so to is the actual number of instruments in daily use is high, and they serve important roles in the fields where they're used. This chapter presents a technical introduction to the different ways particle accelerators are used to produce neutrons, an historical overview of the early development of neutron-producing particle accelerators, a description of some current industrial accelerator systems, narratives of the fields where neutron-producing particle accelerators are used today, and comments on future trends in the industrial uses of neutron producing particle accelerators.

  10. Neutron tomography

    Science.gov (United States)

    Crump, James C., III; Richards, Wade J.; Shields, Kevin C.

    1995-07-01

    The McClellan Nuclear Radiation Center's (MNRC) staff in conjunction with a Cooperative Research and Development Agreement (CRDA) with the U.C. Santa Barbara facility has developed a system that can be used for aircraft inspection of jet engine blades. The problem was to develop an inspection system that can detect very low concentrations of hydrogen (i.e., greater than 100 ppm) in metal matricies. Specifically in Titanium alloy jet engine blades. Entrapment and precipitation of hydrogen in metals is an undesirable phenomenon which occurs in many alloys of steel and titanium. In general, metals suffer a loss of mechanical properties after long exposures to hydrogen, especially at high temperatures and pressures, thereby becoming embrittled. Neutron radiography has been used as a nondestructive testing technique for many years. Neutrons, because of their unique interactions with materials, are especially useful in the detection of hydrogen. They have an extremely high interaction cross section for low atomic number nuclei (i.e., hydrogen). Thus hydrogen in a metal matrix can be visualized using neutrons. Traditional radiography is sensitive to the total attenuation integrated over the path of radiation through the material. Increased sensitivity and quantitative cross section resolution can be obtained using three-dimensional volumetric imaging techniques such as tomography. The solution used to solve the problem was to develop a neutron tomography system. The neutron source is the McClellan Nuclear Radiation Center's 1 MW TRIGA reactor. This paper describes the hardware used in the system as well as some of the preliminary results.

  11. HotSpotter? Neutron/Gamma Detector

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Z.W.

    2003-04-01

    The HotSpotter{trademark} Neutron/Gamma Detector combines in a single detecting module high sensitivity to gamma rays up to 3 MeV and sensitivity to neutrons. Using a 15 mm cubic CdWO{sub 4} (cadmium tungstate) crystal mounted on a 25 mm photomultiplier, the instrument realizes a factor of 5 increased photopeak efficiency over NaI(Tl) at 1 MeV, and a factor of 2 improvement over CsI(Tl). The addition of a 0.5 mm layer of {sup 10}B- impregnated epoxy covering the crystal provides neutron sensitivity without sacrificing gamma ray spectroscopic characteristics. Neutrons are detected by the presence of the 478 keV gamma from the {sup 10}B(n,{alpha}){sup 7}Li* reaction. In this paper, we describe the electronics and software of the instrument, and some of its characteristics.

  12. A history of neutrons in biology: the development of neutron protein crystallography at BNL and LANL.

    Science.gov (United States)

    Schoenborn, Benno P

    2010-11-01

    The first neutron diffraction data were collected from crystals of myoglobin almost 42 years ago using a step-scan diffractometer with a single detector. Since then, major advances have been made in neutron sources, instrumentation and data collection and analysis, and in biochemistry. Fundamental discoveries about enzyme mechanisms, biological complex structures, protein hydration and H-atom positions have been and continue to be made using neutron diffraction. The promise of neutrons has not changed since the first crystal diffraction data were collected. Today, with the developments of beamlines at spallation neutron sources and the use of the Laue method for data collection, the field of neutrons in structural biology has renewed vitality.

  13. Data reduction for time-of-flight small-angle neutron scattering with virtual neutrons

    Science.gov (United States)

    Du, Rong; Tian, Haolai; Zuo, Taisen; Tang, Ming; Yan, Lili; Zhang, Junrong

    2017-09-01

    Small-angle neutron scattering (SANS) is an experimental technique to detect material structures in the nanometer to micrometer range. The solution of the structural model constructed from SANS strongly depends on the accuracy of the reduced data. The time-of-flight (TOF) SANS data are dependent on the wavelength of the pulsed neutron source. Therefore, data reduction must be handled very carefully to transform measured neutron events into neutron scattering intensity. In this study, reduction algorithms for TOF SANS data are developed and optimized using simulated data from a virtual neutron experiment. Each possible effect on the measured data is studied systematically, and suitable corrections are performed to obtain high-quality data. This work will facilitate scientific research and the instrument design at China Spallation Neutron Source.

  14. Competência para prestar cuidado de enfermagem transcultural à pessoa com deficiência: instrumento de autoavaliação Competencia para prestar cuidado de enfermería transcultural a personas con deficiencia: instrumento de autoevaluación Competency to provide cross-cultural nursing care for people with disability: a self-assessment instrument

    Directory of Open Access Journals (Sweden)

    Lorita Marlena Freitag Pagliuca

    2012-10-01

    Cuidado de Enfermería Transcultural a Personas con Deficiencia, específicamente sordera, ceguera y baja visión, deficiencia física y deficiencia mental, respecto a los aspectos de cumplimentar, aceptar, ayudar, conocer y abogar. Se concluye que la teoría reúne características para el cuidado a la persona con deficiencia.This study addresses the Cross-Cultural Nursing Theory, which develops foundations for care delivery, as the essence of nursing work, based on anthropology, which supports and explains culture and care aspects. This reflexive study was based on the Theory Analysis method to study the concepts aimed at constructing a Self-Assessment Instrument of Competencies for Cross-Cultural Care to Disabled People. After analyzing the main concepts, Culturally Competent Care and Cultural Communication, were analyzed, as well as the sub-concepts: assessment, values, bio-cultural diversity, skill, knowledge, identity, code and cultural empathy. The analysis cycle of cultural values supporting self-assessment was summarized. The Self-Assessment Instrument of Competencies for Cross-Cultural Nursing Care to Disabled People was constructed, specifically deafness, blindness or low sight, physical impairment and mental impairment, regarding greeting, accepting, helping, knowing and advocating. It is concluded that the theory joins characteristics for care delivery to disabled people.

  15. Instrument to screen cases of pervasive developmental disorder: a preliminary indication of validity Instrumento para rastreamento dos casos de transtorno invasivo do desenvolvimento: estudo preliminar de validação

    Directory of Open Access Journals (Sweden)

    Fábio Pinato Sato

    2009-03-01

    Full Text Available OBJECTIVE: To translate into Portuguese, back-translate, culturally adapt and validate a screening instrument for pervasive developmental disorder, the Autism Screening Questionnaire, for use in Brazil. METHOD: A sample of 120 patients was selected based on three groups of 40: patients with a clinical diagnosis of pervasive developmental disorder, Down syndrome, or other psychiatric disorders. The self-administered questionnaire was applied to the patients' legal guardians. Psychometric measures of the final version of the translated questionnaire were tested. RESULTS: The score of 15 had sensitivity of 92.5% and specificity of 95.5% as a cut-off point for the diagnosis of pervasive developmental disorder. Internal validity for a total of 40 questions was 0.895 for alpha and 0.896 for KR-20, ranging from 0.6 to 0.8 for both coefficients. Test and retest reliability values showed strong agreement for most questions. CONCLUSIONS: The final version of this instrument, translated into Portuguese and adapted to the Brazilian culture, had satisfactory measurement properties, suggesting preliminary validation proprieties. It was an easy-to-apply, useful tool for the diagnostic screening of individuals with pervasive developmental disorder.OBJETIVO: Tradução, retro-versão, adaptação cultural e validação do Autism Screening Questionnaire para a língua portuguesa e para o seu uso no Brasil. MÉTODO: Foi selecionada uma amostra inicial de 120 pacientes, encaminhados de duas clínicas privadas e uma pública, divida em três grupos de 40 pacientes distintos: pacientes com diagnóstico clínico de transtornos globais do desenvolvimento ou transtornos invasivos do desenvolvimento; de síndrome de Down e de outros transtornos psiquiátricos. O questionário foi aplicado aos responsáveis legais dos pacientes seguindo os padrões de um questionário auto-aplicável. As medidas psicométricas do questionário traduzido, na sua versão final, foram

  16. La forma urbana del medio ambiente construido: Hacia una propuesta de estructuración para el instrumento Plan Regulador Comunal. / The urban form of the built environment: towards a proposed structure for the instrument Communal Regulating Plan.

    Directory of Open Access Journals (Sweden)

    Cárdenas Jirón, Luz Alicia

    2000-08-01

    Full Text Available La forma urbana del medio ambiente construido es el elemento central de este artículo, abordado desde dos perspectivas: en primer lugar la crítica de la forma urbana resultante de un instrumento de planificación y en segundo lugar una propuesta de estructuración de la forma urbana para el Plan Regulador Comunal. Con este objeto, se presenta un modelo cartográfico para entregar una pauta metodológica de los aspectos relevantes a la forma urbana que debieran tomarse en cuenta al momento de planificar y gestionar la ciudad. /The urban form of the built environment is the core element of this article. Two approaches have been developed to deal with it, firstly, a criticism of the urban form as a result of the town planning instrument and secondly a proposal to structure the urban form for Plan Regulador Comunal. Given that a cartographic model is showed as an example to deal with relevant issues in relation to the urban form. The model tries to give a methodological guide to the urban planners and managers.

  17. Desenvolvimento de um instrumento brasileiro para avaliação da cultura organizacional Development of a Brazilian instrument for evaluation of organizational culture

    Directory of Open Access Journals (Sweden)

    Maria Cristina Ferreira

    2002-07-01

    Full Text Available Foi objetivo do presente trabalho desenvolver e analisar as características psicométricas de um instrumento brasileiro destinado a identificar os valores e práticas que configuram a cultura de uma organização. Tomando por base a análise do conteúdo de entrevistas realizadas com diretores ou gerentes de várias empresas, a versão inicial da escala compôs-se de 126 afirmativas em formato Likert, a qual foi respondida por 823 membros de diversas organizações. Análises fatoriais dos eixos principais, com rotação oblíqua, realizadas separadamente no conjunto de itens concernentes aos valores e às práticas organizacionais, revelaram que soluções de quatro e de três fatores, respectivamente, eram as que melhor representavam a estrutura interna das escalas. Os índices de consistência interna desses fatores, calculados através do coeficiente Alfa de Cronbach, variaram entre 0,74 e 0,93. Concluiu-se que as características psicométricas do instrumento recomendam seu uso em pesquisas brasileiras destinadas a avaliar a cultura organizacional.The present paper aimed to develop and analyze the psychometric characteristics of a Brazilian instrument designed to identify the values and practices that shape the culture of an organization. Based on the content analysis of interviews with directors or managers from various enterprises, the initial version of the scale was composed of 126 affirmatives, Likert format, and was presented to 823 members from different organizations. The principal factor analysis axis with oblique rotation done separately in the total amount of items related to the values and to the organizational practices revealed that a four factor structure and a three factor structure, respectively, were the best representations of the scales. The internal consistency indexes, calculated by Cronbach’s Alpha coefficients, ranged between .74 and .93. It was concluded that the psychometric characteristics of the instrument

  18. Advanced Neutron Source (ANS) Project progress report

    Energy Technology Data Exchange (ETDEWEB)

    McBee, M.R.; Chance, C.M. (eds.) (Oak Ridge National Lab., TN (USA)); Selby, D.L.; Harrington, R.M.; Peretz, F.J. (Oak Ridge National Lab., TN (USA))

    1990-04-01

    This report discusses the following topics on the advanced neutron source: quality assurance (QA) program; reactor core development; fuel element specification; corrosion loop tests and analyses; thermal-hydraulic loop tests; reactor control concepts; critical and subcritical experiments; material data, structural tests, and analysis; cold source development; beam tube, guide, and instrument development; hot source development; neutron transport and shielding; I C research and development; facility concepts; design; and safety.

  19. Performances of Neutron Scattering Spectrometers on a Compact Neutron Source

    CERN Document Server

    Fabrèges, Xavier; Ott, Frédéric; Chauvin, Nicolas; Schwindling, Jérôme; Letourneau, Alain; Marchix, Anthony

    2016-01-01

    There is currently a big effort put into the operation and construction of world class neutron scattering facilities (SNS and SNS-TS2 in the US, J-PARC in Japan, ESS in Europe, CSS in China, PIK in Russia). On the other hand, there exists a network of smaller neutron scattering facilities which play a key role in creating a large neutron scattering community who is able to efficiently use the existing facilities. With the foreseen closure of the ageing nuclear research reactors, especially in Europe there is a risk of seeing a shrinking of the community who would then be able to use efficiently the world class facilities. There is thus a reflection being conducted in several countries for the replacement of smaller research reactors with low energy accelerator based sources. We consider here a reference design for a compact neutron source based on existing accelerator components. We estimate the performances of various types of neutron scattering instruments built around such a source. The results suggest tha...

  20. Development of compact accelerator neutron source

    Directory of Open Access Journals (Sweden)

    Letourneau Alain

    2017-01-01

    Full Text Available There is a worldwide growing interest for small-scale and reduced-cost neutron sources not based on nuclear fission. High-intensity proton or deuteron beams impinging on light materials could be used to produce such neutron sources with intensities or brightness comparable to nuclear reactor for dedicated experiments. To develop such technologies several key technological issues have to be addressed. Among them the neutron production and the maximization of the neutron extraction and transport to the instrument is a key parameter for the design of high-brightness sources adapted for the required application. This issue have to be addressed with validated and predictive Monte-Carlo simulations. In this paper we present preliminary results on the use of Geant4 in the context of Compact Accelerator based Neutron Source (CANS developments.

  1. Characterization of different qualities in X-rays, for instruments calibration in radiological protection; Caracterizacion de diferentes calidades en rayos X, para calibracion de instrumentos en proteccion radiologica

    Energy Technology Data Exchange (ETDEWEB)

    Cejudo A, J.; Tovar M, V. M.; Vergara M, F., E-mail: jesus.cejudo@inin.gob.m [ININ, Departamento de Metrologia de Radiaciones Ionizantes, Laboratorio Secundario de Calibracion Dosimetrica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2010-09-15

    In the Secondary Laboratory of Dosimetric Calibration in Mexico was realized the qualities characterization of the series X-rays RQR reported in the International Code of Practices in Dosimetry and Diagnostic Radiology No. 457, using attenuator filters of high purity aluminum and ionizing radiation equipment of inherent filtration of 4 mm Be with and emergent X-radiation beam of 40 grades. For the attenuation was used a geometric arrangement with three beam limiters and a monitor camera prepared on the established form in the mentioned technical report, and a spherical ionization chamber with collection volume of 3.6 cm{sup 3}, aligning its geometric center with the focus of X-rays tube to get that the incident radiation direction will be perpendicular to the ionization chamber. From the perspective of the radiological protection is important to know the X-radiation quality for the application dedicated to the instruments calibration and can to give to these the traceability to a reference laboratory, this way the quality combination and reference chamber can give as a result a procedure for the evaluation of the entrance in surface dose to estimate the dose orientate levels, specified in the basic standards of safety. (Author)

  2. Conceptual moderator studies for the Spallation Neutron Source short-pulse second target station

    Energy Technology Data Exchange (ETDEWEB)

    Gallmeier, F. X., E-mail: gallmeierfz@ornl.gov; Lu, W.; Riemer, B. W.; Zhao, J. K.; Herwig, K. W.; Robertson, J. L. [Instrument and Source Division, Oak Ridge National Laboratory, P.O. Box 2008, MS6466, Oak Ridge, Tennessee 37831 (United States)

    2016-06-15

    Candidate moderator configurations for a short-pulse second target station (STS) at the Oak Ridge National Laboratory Spallation Neutron Source (SNS) have been identified using a global optimizer framework built around the MCNPX particle transport code. Neutron brightness metrics were selected as the figure-of-merit. We assumed that STS would use one out of six proton pulses produced by an SNS accelerator upgraded to operate at 1.3 GeV proton energy, 2.8 MW power and 60 Hz repetition rate. The simulations indicate that the peak brightness can be increased by a factor of 5 and 2.5 on a per proton pulse basis compared to the SNS first target station for both coupled and decoupled para-hydrogen moderators, respectively. Additional increases by factors of 3 and 2 were demonstrated for coupled and decoupled moderators, respectively, by reducing the area of neutron emission from 100 × 100 mm{sup 2} to 20 × 20 mm{sup 2}. This increase in brightness has the potential to translate to an increase of beam intensity at the instruments’ sample positions even though the total neutron emission of the smaller moderator is less than that of the larger. This is especially true for instruments with small samples (beam dimensions). The increased fluxes in the STS moderators come at accelerated poison and de-coupler burnout and higher radiation-induced material damage rates per unit power, which overall translate into lower moderator lifetimes. A first effort was undertaken to group decoupled moderators into a cluster collectively positioning them at the peak neutron production zone in the target and having a three-port neutron emission scheme that complements that of a cylindrical coupled moderator.

  3. Instrumento para a abordagem psicossocial do indivíduo e da família na assistência domiciliar: condições de aplicabilidade Instrumento para el abordaje psicosocial del indivíduo y familia en la asistencia domiciliaria: las condiciones de aplicabilidad Psychosocial instrument to approach person and family in home care: conditions of applicability

    Directory of Open Access Journals (Sweden)

    Vilanice Alves de Araújo Püschel

    2005-06-01

    Full Text Available Na Assistência Domiciliar (AD, o modelo clínico e hospitalar tem sido hegemônico. A abordagem psicossocial mostra-se necessária para os problemas identificados no âmbito domiciliar. Este artigo tem como objetivos: apresentar um instrumento de abordagem psicossocial do indivíduo e da família na assistência domiciliar e mostrar as condições de aplicabilidade do modelo psicossocial no domicílio, a partir da utilização desse instrumento. Esse instrumento foi aplicado pelas participantes de um curso de capacitação para a AD numa abordagem psicossocial, em pessoas doentes e familiares que estavam recebendo o cuidado no domicílio. Verificou-se que este é viável, porém à onipotência própria da clínica se sobrepõe uma impotência quase absoluta de raciocínio clínico-psicossocial. Há necessidade de validação desse instrumento e da composição de um campo de pesquisa significativo para a qualificação do ensino e da prática assistencial na AD.En la asistencia domiciliaria (AD el modelo clínico y hospitalario ha sido hegemónico. El abordaje psicosocial muestra que es necesario para los problemas identificados en el ámbito domiciliario. Este artículo tiene como objetivos: presentar un instrumento de abordaje psicosocial al individuo y a la familia en la asistencia domiciliaria y mostrar las condiciones de aplicabilidad del modelo psicosocial en el domicilio a partir de la utilización de ese instrumento. El instrumento fue aplicado, por las participantes de un curso de capacitación para la AD con abordaje psicosocial, en personas enfermas y familiares que estaban recibiendo el cuidado en el domicilio. Se verificó que éste es viable, sin embargo la omnipotencia propia de la clínica se sobrepone a una impotencia casi absoluta de raciocinio clínico-psicosocial. Hay necesidad de validar el instrumento y de la composición de un campo de investigación significativo para la calificación de la enseñanza y de la pr

  4. Desarrollo y validación de un instrumento para la evaluación inicial de enfermeira Desenvolvimento e validação de um instrumento para a avaliação inicial de enfermagem Development and validation of an instrument for initial nursing assessment

    Directory of Open Access Journals (Sweden)

    Cayetano Fernández-Sola

    2012-12-01

    Full Text Available Este estudio, desarrollado de abril a julio de 2008, objetiva desarrollar y validar un instrumento para orientar la evaluación de enfermería en parámetros asistenciales y docentes en Santa Cruz, Bolivia. Participaron doce enfermeras bolivianas y se utilizaron el análisis de documentos y técnicas de consenso para definir las categorías y criterios a ser incluidas en el instrumento. Estas categorías son: la evaluación física y los 11 Patrones Funcionales de Salud de Gordon. El instrumento se caracteriza por ser breve, de sencilla comprensión y por centrarse en el enfermero. No incluye elementos de evaluación física avanzada, pero sí criterios de estilos de vida y autonomía del paciente. El desarrollo de estos instrumentos contribuye a la calidad de los registros, favorece el juicio clínico y la aplicación del proceso a la enfermería, refuerza el papel del enfermero, favoreciendo la sistematización de su práctica.Este estudo, realizado entre abril e julho de 2008, teve como objetivo desenvolver e validar um instrumento para orientar a avaliação de enfermagem em parâmetros assistenciais e docentes, em Santa Cruz, na Bolívia. Participaram do estudo doze enfermeiras bolivianas, e utilizaram-se a análise de documentos e técnicas de consenso para definir as categorias e critérios a incluir no instrumento. As categorias definidas foram a avaliação física e os onze Padrões Funcionais da Saúde de Gordon. O instrumento caracteriza-se por ser breve, de fácil compreensão e por centrar-se no enfermeiro. Não foram incluídos elementos de avaliação física avançada, mas sim critérios de estilos de vida e autonomia do paciente. O desenvolvimento do instrumento contribuiu para a qualidade dos registros, favorecendo o juízo clínico e a aplicação do processo à enfermagem, reforçando o papel do enfermeiro e contribuindo para a sistematização da sua prática.The objective of this study, conducted in Bolivia from April to

  5. Polarized neutron reflectometry at Dhruva reactor

    Indian Academy of Sciences (India)

    Surendra Singh; Saibal Basu

    2004-08-01

    Polarized neutron reflectometry (PNR) is an ideal non-destructive tool for chemical and magnetic characterization of thin films and multilayers. We have installed a position sensitive detector-based polarized neutron reflectometer at Dhruva reactor, Trombay. In this paper we will discuss the results obtained from this instrument for two multilayer samples. The first sample is a (Ni–Mo alloy)/Ti multilayer sample. We have determined the chemical structure of this multilayer by unpolarized neutron reflectometry (NR). The other sample is a Fe/Ge multilayer sample for which we obtained the chemical structure by NR and magnetic moment per Fe atom by PNR.

  6. Neutron Scattering in Biology Techniques and Applications

    CERN Document Server

    Fitter, Jörg; Katsaras, John

    2006-01-01

    The advent of new neutron facilities and the improvement of existing sources and instruments world wide supply the biological community with many new opportunities in the areas of structural biology and biological physics. The present volume offers a clear description of the various neutron-scattering techniques currently being used to answer biologically relevant questions. Their utility is illustrated through examples by some of the leading researchers in the field of neutron scattering. This volume will be a reference for researchers and a step-by-step guide for young scientists entering the field and the advanced graduate student.

  7. Prospects in MPGDs development for neutron detection

    CERN Document Server

    Croci, Gabriele; Resnati, Filippo

    2016-01-01

    The aim of this document is to summarise the discussion and the contributions from the 2nd Academia-Industry Matching Event on Detecting Neutrons with MPGDs which took place at CERN on the 16th and the 17th of March 2015. These events provide a platform for discussing the prospects of Micro-Pattern Gaseous Detectors (MPGDs) for thermal and fast neutron detection, commercial constraints and possible solutions. The aim is to foster the collaboration between the particle physics community, the neutron detector users, instrument scientists and fabricants.

  8. Adaptação transcultural para o Brasil do instrumento Caregiver Abuse Screen (CASE para detecção de violência de cuidadores contra idosos Cross-cultural adaptation to Brazil of the instrument Caregiver Abuse Screen (CASE for detection of abuse of the elderly by caregivers

    Directory of Open Access Journals (Sweden)

    Carlos Montes Paixão Jr

    2007-09-01

    Full Text Available Este artigo descreve a primeira parte da adaptação transcultural da versão em português, para o Brasil, do Caregiver Abuse Screen (CASE, um instrumento simplificado para suspeição de violência contra o idoso. O CASE foi originalmente desenvolvido no Canadá e utilizado para rastrear violências em idosos entrevistando seus cuidadores. O processo de avaliação de equivalências conceitual e de itens, que envolveu uma ampla e sistemática revisão bibliográfica, consistiu de uma discussão em grupo de expertos. A equivalência semântica envolveu duas traduções e respectivas retraduções em paralelo; uma avaliação de equivalência de significados referencial e geral entre o CASE original e as versões em português; discussões posteriores com o grupo de expertos para definir a versão final; e um pré-teste com quarenta cuidadores de pacientes idosos em um serviço de atendimento ambulatorial de geriatria. Foi possível estabelecer uma versão em português para o Brasil com boa qualidade de equivalência conceitual, de itens e semântica. Embora os resultados aqui descritos sejam encorajadores, eles devem ser reavaliados à luz de evidências psicométricas (equivalência de mensuração que oportunamente serão apresentadas por este grupo de estudo.This first of two papers focuses on the first part in the cross-cultural adaptation of the Portuguese-language version of Caregiver Abuse Screen (CASE, a brief instrument for detecting domestic violence against the elderly. CASE was originally developed in Canada and used to screen violence against the elderly by interviewing their caregivers. Besides a broad literature review, the evaluation of conceptual and item equivalences involved expert discussion groups. Semantic equivalence included the following steps: two translations and respective back-translations; an evaluation of referential and general (connotative equivalence between the original instrument and each version; further

  9. Upgrade of the neutron guide system at the OPAL Neutron Source

    Science.gov (United States)

    Rodriguez, D. Martin; Kennedy, S. J.; Klose, F.

    2010-11-01

    The new research reactor at ANSTO (OPAL) is operating with seven neutron beam instruments in the user programme and three more under construction. The reactor design provides for expansion of the facility to eighteen instruments, and much of the basic infrastructure is already in place. However, an expansion of the neutron guide system is needed for further beam instruments. For this purpose, several possibilities are under consideration, such as insertion of multi-channel neutron benders in the existing cold guides or the construction of a new elliptic cold guide. In this work Monte Carlo (MC) simulations have been used to evaluate performance of these guide configurations. Results show that these configurations can be competitive with the best instruments in the world.

  10. The relevance of cross-cultural adaptation and clinimetrics for physical therapy instruments A importância da adaptação transcultural e clinimétrica para instrumentos de fisioterapia

    Directory of Open Access Journals (Sweden)

    CG Maher

    2007-08-01

    Full Text Available BACKGROUND: Self-report outcome measures (questionnaires are widely used by physiotherapists for measuring patient's health status or treatment outcomes. Most of these measurement tools were developed in English and their usefulness is very limited in non-English speaking countries such as Brazil. The only way to solve this problem is to properly adapt the relevant questionnaires into a target language and culture (e.g. Brazilian-Portuguese and then test the instrument by checking its psychometric (clinimetric characteristics. OBJECTIVES: The purpose of this paper was to present relevant issues in the process of cross-cultural adaptations and clinimetric testing for self-report outcome measurements. Advice on how to perform a cross-cultural adaptation, how to properly check the clinimetric properties, how to select a relevant questionnaire and how to evaluate the quality of an adapted questionnaire are provided. Additionally we present all Brazilian-Portuguese cross-cultural adaptations of low back pain measurements that we know of. CONCLUSIONS: There is a clear need for more effort in the field of cross-cultural adaptation and clinimetrics, without proper instruments, the management of patients from non-English speaking countries is compromised.INTRODUÇÃO: Questionários vem sendo amplamente utilizados por fisioterapeutas para medir a condição de saúde do paciente ou dos resultados de tratamento. A maioria desses instrumentos para avaliação foi desenvolvida em inglês, sendo seu uso bastante limitado em países que não usam o inglês como língua nativa, a exemplo do Brasil. A única forma de resolver esse problema é através de uma adaptação apropriada dos questionários relevantes para um alvo lingüístico e cultural (por exemplo, português do Brasil e então testar suas características psicométricas (clinimétricas. OBJETIVO: A finalidade deste artigo foi a apresentar os tópicos relevantes no processo das adapta

  11. Educação em valores: um possível caminho para a superação da razão instrumental rumo à formação do cidadão

    Directory of Open Access Journals (Sweden)

    Natalia Branco Lopes Krawczun

    2014-01-01

    Full Text Available O trabalho tem como objetivo propor uma reflexão a respeito da introdução de valores na ação educativa institucional, cujo objetivo volta-se à implementação de um espaço profícuo ao desenvolvimento do cidadão. Para isso, a partir das obras da filósofa espanhola Adela Cortina e do filósofo alemão Jürgen Habermas busca-se estabelecer um raciocínio a respeito da inevitável inserção de valores na ação, destinada a provocar os educandos à incorporação de uma postura participativa, que é essencial para elevá-los à condição de cidadão. Para isso, parte-se inicialmente da análise das diferentes formas de estabelecimento das relações interpessoais. A partir das considerações de Cortina acerca dos estudos de Jonathan Sacks e Thomas Hobbes, realiza-se um cotejo entre aliança e contrato, demonstrando que embora os direitos e deveres do cidadão estejam estabelecidos por meio de um contrato, os seus fundamentos e a garantia de seu funcionamento consubstanciam-se na aliança. Outro aspecto abordado, refere-se à superação da ação instrumental, considerada por Cortina como nefasta à formação do sujeito autônomo. Destaca-se a contribuição da educação escolar, em todos os seus níveis, no tocante ao desenvolvimento de uma sociedade democrática que conta com a participação ativa de seus sujeitos pertencentes e conscientes de suas alianças. Aponta-se que para que esse projeto aproxime-se da realidade é fundamental que os educadores, bem como os demais agentes vinculados às instituições educacionais, articulem em sua práxis os valores mínimos destacados por Adela Cortina, quais sejam: liberdade, igualdade, respeito ativo, solidariedade e o diálogo.

  12. Instrumentation Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Provides instrumentation support for flight tests of prototype weapons systems using a vast array of airborne sensors, transducers, signal conditioning and encoding...

  13. The NIST NBSR and Cold Neutron Research Facility

    Energy Technology Data Exchange (ETDEWEB)

    Rush, J.J. [National Inst. of Standards and Technology, Guthersburg, MD (United States)

    1994-12-31

    The 20 MW Neutron Beam Split-Core Reactor (NBSR) has nine radial thermal beam tubes, and a large, highly accessible (35cm) cold source serving an extensive network of eight guide tubes. In operation or under construction are twenty-five neutron beam instruments (20 for neutron scattering) and about a dozen other facilities for neutron trace analysis, dosimetry and irradiation. The 6 x 15cm cold neutron guides are coated with {sup 58}Ni, and the last three being installed this fall are coated top and bottom with supermirrors for further increases in intensity. The new semi-spherical liquid hydrogen source will be described, along with the eight scattering instruments (reflectometry, SANS and high-resolution spectroscopy) which have, or will have, an extensive use in biological research. These instruments will likely provide the best overall capability in the U.S. for the next decade for a number of applications in biomolecular structure and dynamics.

  14. Instrumento para evaluar la adherencia a tratamientos en pacientes con factores de riesgo cardiovascular Instrumento para avaliar a aderência a tratamentos em pacientes com fatores de risco cardiovas Instrument to assess treatment adhesion in patients with cardiovascular risk factors

    Directory of Open Access Journals (Sweden)

    CONSUELO ORTIZ SUÁREZ

    2010-12-01

    é válido e confiável e pode ser aplicado em futuros estudos sobre a aderência, visando compreender melhor a aderência e seus fatores determinantes, para assim, partindo dos resultados dos mesmos, desenvolver planos de melhoria nas práticas de cuidado na procura de benefícios para os pacientes e suas famílias, promovendo nessas pessoas uma aderência efetiva.This descriptive and methodological study with quantitative approach intended to determine the validity of construct and reliability of the instrument “Factors that affect the adhesion of the pharmacological and non-pharmacological treatment in patients with cardiovascular risk factors”. Information was gathered through an instrument designed by Bonilla e De Reales in 2006. This instrument was formed by 53 items and four domains, considering face value, content and reliability. The instrument was applied to 485 patients that met the inclusion criteria. Construct validity was applied to the instrument through an exploratory factorial analysis to determine the correlation among the variables and the four dimensions, using the method of main component extraction and varimax rotation with Kaiser. The internal consistency of the instrument was achieved with the results drawn from the factorial analysis (24 items and 4 domains, through the Cronbach Alpha coefficient. The aforesaid construct validity allowed for reducing the number of items from 53 to 24 through factorial analysis, without changing the 4 domains of the instrument; the internal consistency index obtained through the Cronbach Alpha was 0,60, which is deemed appropriate. Then, a new version of the instrument was created, grouping 24 items in four factors that account for 45% of the variance. This demonstrated that the variables were correlated with the measuring targets, which allows for theoretically grounding the construct, increasing its applicability for nursing professionals in different domains of health care. This shows that the

  15. Instrument to assess treatment adhesion in patients with cardiovascular risk factors Instrumento para evaluar la adherencia a tratamientos en pacientes con factores de riesgo cardiovascular Instrumento para avaliar a aderência a tratamentos em pacientes com fatores de risco cardiovascular

    Directory of Open Access Journals (Sweden)

    ORTIZ SUÁREZ CONSUELO

    2010-12-01

    Full Text Available

    This descriptive and methodological study with quantitative approach intended to determine the validity of construct and reliability of the instrument “Factors that affect the adhesion of the pharmacological and non-pharmacological treatment in patients with cardiovascular risk factors”.

    Information was gathered through an instrument designed by Bonilla e De Reales in 2006. This instrument was formed by 53 items and four domains, considering face value, content and reliability. The instrument was applied to 485 patients that met the inclusion criteria.

    Construct validity was applied to the instrument through an exploratory factorial analysis to determine the correlation among the variables and the four dimensions, using the method of main component extraction and varimax rotation with Kaiser. The internal consistency of the instrument was achieved with the results drawn from the factorial analysis (24 items and 4 domains, through the Cronbach Alpha coefficient.

    The aforesaid construct validity allowed for reducing the number of items from 53 to 24 through factorial analysis, without changing the 4 domains of the instrument; the internal consistency index obtained through the Cronbach Alpha was 0,60, which is deemed appropriate. Then, a new version of the instrument was created, grouping 24 items in four factors that account for 45% of the variance. This demonstrated that the variables were correlated with the measuring targets, which allows for theoretically grounding the construct, increasing its applicability for nursing professionals in different domains of health care.

    This shows that the instrument is valid and reliable, and applicable in future studies on adhesion in view to gain a deeper insight into adhesion and its determining factors so as to use them in developing improvement plans in health care practices in favor of patients and their families

  16. Assembly of a laboratory for calibration in brachytherapy. Comparison of responses with different instrumentation; Montaje de un laboratorio para calibraciones en braquiterapia. Comparacion de respuestas con diferente instrumentacion

    Energy Technology Data Exchange (ETDEWEB)

    Pirchio, R.; Saravi, M. [CNEA, Pbro. J. Gonzalez y Aragon No. 16 (B1802AYA) Ezeiza, Buenos Aires (Argentina)]. e-mail: pirchio@cae.cnea.gov.ar

    2006-07-01

    A common practice in quality control programs for dosimetry in brachytherapy is the source calibration. The AAPM (American Association of Physicists in Medicine) in the Task Group No. 40 (TG-40) it recommends that each institution that offers a brachytherapy service verifies the intensity of each source provided by the maker with secondary traceability. For such a reason it is necessary to have laboratories able to make calibrations of sources, traceable electrometer-chambers to primary or credited laboratories. The Regional Center of Reference of Dosimetry of the CNEA (National Commission of Atomic Energy) it is in the stage of finalization of the assembly of a Laboratory for source calibration and use equipment in brachytherapy. For it has two ionization chambers well type and two electrometers gauged by the Accredited Dosimetry Calibration Laboratory of the University of Wisconsin. Also account with a wide variety of supports and with a tube of {sup 137}Cs pattern 3M model 6500/6D6C. The procedures for the calibration of sources and equipment were elaborated starting from the TECDOC-1274. On the other hand, its were carried out measurements with different instrumentation for the comparison of responses and at the same time to implement the calibration procedures. For it, its were used chambers and electrometers of the institution, of hospitals and of the national company 'Solydes'. In the measurements its were used seeds of {sup 125}I taken place in Argentina and the tube of {sup 137}Cs pattern mentioned previously. In first place it was proceeded to the determination of the center of the region of the plateau in the axial response for the seeds of Iodine-125 and the tube of Cesium-137 pattern using different chambers. Later on its were carried out measurements of accumulated loads during a certain interval of time in this position. The calibration factors of each chamber were determined, N{sub Sk} ({mu}Gy m{sup 2} h{sup -1} A{sup -1}), as the quotient

  17. 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...

  18. The design of the inelastic neutron scattering mode for the Extreme Environment Diffractometer with the 26 T High Field Magnet

    Energy Technology Data Exchange (ETDEWEB)

    Bartkowiak, Maciej, E-mail: maciej.bartkowiak@helmholtz-berlin.de; Stüßer, Norbert; Prokhnenko, Oleksandr

    2015-10-11

    The Extreme Environment Diffractometer is a neutron time-of-flight instrument, designed to work with a constant-field hybrid magnet capable of reaching fields over 26 T, unprecedented in neutron science; however, the presence of the magnet imposes both spatial and technical limitations on the surrounding instrument components. In addition to the existing diffraction and small-angle neutron scattering modes, the instrument will operate also in an inelastic scattering mode, as a direct time-of-flight spectrometer. In this paper we present the Monte Carlo ray-tracing simulations, the results of which illustrate the performance of the instrument in the inelastic-scattering mode. We describe the focussing neutron guide and the chopper system of the existing instrument and the planned design for the instrument upgrade. The neutron flux, neutron spatial distribution, divergence distribution and energy resolution are calculated for standard instrument configurations.

  19. Principais instrumentos para avaliação da disfunção temporomandibular, parte II: critérios diagnósticos; uma contribuição para a prática clínica e de pesquisa Main instruments for assessing temporomandibular disorders, part II: diagnostic criteria; a contribution to clinicians and researchers

    Directory of Open Access Journals (Sweden)

    Thaís Cristina Chaves

    2008-01-01

    Full Text Available Na literatura especializada, encontram-se variados instrumentos para avaliação da disfunção temporomandibular (DTM, sob a forma de índices, questionários, protocolos, escalas e critérios de diagnóstico. Este estudo, dividido em duas partes, visou caracterizar os principais instrumentos de avaliação da DTM disponíveis na literatura, para auxiliar o clínico e o pesquisador na correta escolha da ferramenta apropriada para seus objetivos clínicos ou científicos. Na parte I foram caracterizados dois índices clínicos e três questionários (anamnésicos e funcionais; e, nesta parte II, um questionário funcional e dois conjuntos de critérios diagnósticos. Os índices são ferramentas que organizam a avaliação de sinais e sintomas, pela obtenção de pontuações. Os questionários são melhor aplicados em estudos epidemiológicos. Para avaliação dos eventuais impactos da DTM nas atividades de vida diária, os questionários funcionais são mais adequados. Finalmente, os critérios permitem obter o diagnóstico da disfunção. O RDC/TMD (Research diagnostic criteria for temporomandibular disorders, Critérios diagnósticos para pesquisa em DTM é um dos poucos instrumentos que define critérios operacionais para o diagnóstico clínico. O RDC/TMD, disponível em tradução oficial para o português, tem a maior parte de suas propriedades psicométricas e acurácia verificadas, caracterizando-se como uma das ferramentas mais apropriadas para avaliação da DTM.Several instruments for assessing temporomandibular disorders (TMD are available in literature, such as indices, questionnaires, protocols, scales, and diagnostic criteria. The purpose of this study, divided into two parts, was to characterise main tools available for TMD evaluation, so as to offer both researchers and clinicians guiding information on instrument selection according to their clinical or research needs. Two clinical indices and three (anamnestic and functional

  20. The status of neutron beam utilization in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Hae-Seop; Lee, Chang-Hee; Seong, Baek-Seok; Lee, Jeong-Soo [Neutron Beam Application Project, HANARO Center, Korea Atomic Energy Research Institute., Taejon (Korea)

    1999-10-01

    HANARO (30 MWth) at Korea Atomic Energy Research Institute (KAERI), which reached its first criticality on February 1995, is the multi-purpose research reactor for the application of reactor radiation in a variety of fields such as physics and materials science, irradiation technology, biomedical technology, and neutron activation analysis. For the neutron beam research, seven horizontal beam tubes of different types are available, and HANARO has performed its development plan for a basic set of neutron beam instruments since 1992. A High Resolution Powder Diffractometer (HRPD) and a Neutron Radiography Facility (NRF) has been installed and operated since 1997 and 1996 each. A Four Circle Diffractometer (FCD) and a Small Angle Neutron Spectrometer (SANS) will be operational on 1999 and in 2000 respectively, and a Polarized Neutron Spectrometer (PNS) in 2001. SANS at CN (Cold Neutron) beam tube will be operated using liquid nitrogen cooled Be filter until the cold neutron source is made available. Then, it will be moved to a guide laboratory with proper modification. Research works using the instruments in operation started by internal and external users since their full operation and have been rapidly increasing. Most in-house resources available are being used for on-going development of instruments due to rapidly increasing demands of external users nationwide. In addition to above instruments, a Triple Axis Spectrometer (TAS) and a Neutron Reflectometer which have been strongly requested by external users from universities and industries are under discussion. Then, HANARO will provide the best combination of neutron instruments to meet national research demands and international collaborations, and will be well prepared for future researches by cold neutrons. (author)

  1. 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)

  2. Neutron scattering applications in hydrocarbon materials

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Min Y.; Peiffer, Dennis G. [ExxonMobil Research and Engineering Company, Annandale, NJ (United States); Zhang, Yimin; Rafailovich, Miriam [Dept. of Materials Sci. and Eng., State University of New York, NY (United States)

    2001-03-01

    Neutron scattering methods are a powerful probe to complex fluids, soft matters as well as solid materials of nano- and micro-structures and their related dynamic properties. They complement other microstructural probing tools, such as microscopes, x-ray and light scattering techniques. Because neutron does not carry charges, it interacts only with nuclei of the matter, therefore not only can it penetrate a longer length into matters, it can also see' many features other methods can't due to their lack of proper contrast or heavy absorption. One of the largest contrasts in neutron methods is from hydrogen/deuterium (H/D) difference. Therefore, hydrocarbons can be easily studied by neutrons when H/D isotope substitution is applied. Here at National Institute of Standards and Technology's Center for Neutron Research (NCNR) in Gaithersburg, Maryland, one of the USA's premier neutron scattering facilities, we have been using neutron scattering techniques to study microstructures of asphaltenes, waxes, gas hydrates, porous media, surfactant solutions, engine oils, polymers, nanocomposites, fuel cell element and other hydrocarbon materials. With the completion of a new Neutron Spin Echo instrument, we can also look at the dynamics of the above mentioned systems. (author)

  3. 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)...

  4. Ecological corridors as an instrument for the desfragmentation of tropical forests Corredores ecológicos como ferramenta para a desfragmentação de florestas tropicais

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Sícoli Seoane

    2010-12-01

    Full Text Available

    The expansion of the human land use leads to a severe fragmentation of the natural habitats. Biological corridors may facilitate the movement of organisms among habitat patches and have been frequently adopted as a tool to conserve and restore biodiversity. Metapopulation theory gives the theoretical starting point for the actual biological corridors studies, which are still in their infancy. There are not yet a solid scientific knowledge to recommend the use of biological corridors as a tool in conservation biology. Nevertheless, the effects of forest fragmentation are so severe that the planning and executing of strategies to attenuate it are justifiable, even though research results demonstrating its effectiveness and benefits are not  available.