WorldWideScience

Sample records for ray nuclear interactions

  1. Gross features of nuclear interactions around 1015 eV through observation of gamma ray families

    International Nuclear Information System (INIS)

    Semba, Hiroshi

    1983-01-01

    A systematic analysis is made on the 106 γ-ray families with visible energy in the range of 100--300 TeV observed in the Chacaltaya emulsion chamber experiment. A new method called 'decascading' is introduced to pick up a cluster of γ-rays and electrons in a family, so that the cluster is an air cascade from one parent γ-ray. The application of 'decascading' method to the family data gives information on original γ-rays produced at the atmospheric nuclear interactions. The results are compared with expected ones from the simulation calculation on the base of H-quantum model, and with data from the target interactions at lower energy range (ΣE sub(γ)=20 --100 TeV). The conclusion is that the characteristics of nuclear interactions at the concerned family energy range (E 0 asymptotically equals 1,000 TeV) are in accordance with those at the target interaction range (E 0 asymptotically equals 100 TeV), with increased ratio of frequencies of a heavy fire-ball (SH-quantum) to a small and usual fire-ball (H-quantum). (author)

  2. Cosmic ray nuclear interactions and EAS-triggered families observed by the Chacaltaya hybrid experiment

    International Nuclear Information System (INIS)

    Aoki, H.; Honda, K.; Inoue, N.; Ishii, T.; Kawasumi, N.; Martinic, N.; Ochi, N.; Ohmori, N.; Ohsawa, A.; Tamada, M.; Ticona, R.

    2008-01-01

    Longitudinal and lateral characteristics of the families detected by emulsion chambers in the hybrid experiment with AS-array at Mt. Chacaltaya are studied in detail. Although many groups discuss about an increase of the heavy component in primary cosmic-rays beyond the knee region, it is shown that the observed characteristics of the families accompanied by large shower size, Ne>10 6 , can not be explained by an increase of heavy primaries alone. It is necessary to assume some changes of nuclear interaction in order to explain the observed characteristics of the air-showers accompanied by families

  3. Nuclear interactions of super high energy cosmic-rays observed by mountain emulsion chambers

    International Nuclear Information System (INIS)

    1981-01-01

    Here is presented a summary of joint discussions on the results of three mountain experiments with large-scale emulsion chambers, at Pamir, Mt. Fuji and Chacaltaya. The observation covers gamma-quanta, hadrons and their clusters (called ''families''). Following topics are covered concerning on characteristics of nuclear interactions in energy region of 10 14 - 10 16 eV: 1) rapid dissipation seen in atmospheric diffusion of high energy cosmic-rays, 2) multiplicity and p sub(t) increase in produced pimesons in the fragmentation region, 3) existence of large p sub(t) jets, 4) extremely-hadron-rich family of Centauro type, 5) exotic phenomena at extremely high energy region beyond 10 16 eV. (author)

  4. Interactive Stable Ray Tracing

    DEFF Research Database (Denmark)

    Dal Corso, Alessandro; Salvi, Marco; Kolb, Craig

    2017-01-01

    Interactive ray tracing applications running on commodity hardware can suffer from objectionable temporal artifacts due to a low sample count. We introduce stable ray tracing, a technique that improves temporal stability without the over-blurring and ghosting artifacts typical of temporal post-pr...

  5. Interaction of cosmic ray muons with spent nuclear fuel dry casks and determination of lower detection limit

    Energy Technology Data Exchange (ETDEWEB)

    Chatzidakis, S., E-mail: schatzid@purdue.edu; Choi, C.K.; Tsoukalas, L.H.

    2016-08-21

    The potential non-proliferation monitoring of spent nuclear fuel sealed in dry casks interacting continuously with the naturally generated cosmic ray muons is investigated. Treatments on the muon RMS scattering angle by Moliere, Rossi-Greisen, Highland and, Lynch-Dahl were analyzed and compared with simplified Monte Carlo simulations. The Lynch-Dahl expression has the lowest error and appears to be appropriate when performing conceptual calculations for high-Z, thick targets such as dry casks. The GEANT4 Monte Carlo code was used to simulate dry casks with various fuel loadings and scattering variance estimates for each case were obtained. The scattering variance estimation was shown to be unbiased and using Chebyshev's inequality, it was found that 10{sup 6} muons will provide estimates of the scattering variances that are within 1% of the true value at a 99% confidence level. These estimates were used as reference values to calculate scattering distributions and evaluate the asymptotic behavior for small variations on fuel loading. It is shown that the scattering distributions between a fully loaded dry cask and one with a fuel assembly missing initially overlap significantly but their distance eventually increases with increasing number of muons. One missing fuel assembly can be distinguished from a fully loaded cask with a small overlapping between the distributions which is the case of 100,000 muons. This indicates that the removal of a standard fuel assembly can be identified using muons providing that enough muons are collected. A Bayesian algorithm was developed to classify dry casks and provide a decision rule that minimizes the risk of making an incorrect decision. The algorithm performance was evaluated and the lower detection limit was determined.

  6. Neutron-capture gamma-ray study of levels in 135Ba and description of nuclear levels in the interacting-boson-fermion model

    International Nuclear Information System (INIS)

    Chrien, R.E.; Koene, B.K.S.; Stelts, M.L.; Meyer, R.A.; Brant, S.; Paar, V.; Lopac, V.

    1993-01-01

    We have performed neutron-capture gamma-ray studies on natural and enriched targets of 134 Ba in order to investigate the nuclear levels of 135 Ba. The low-energy level spectra were compared with the calculations using the interacting-boson-fermion model (IBFM) and the cluster-vibration model. The level densities up to 5 MeV that are calculated within the IBFM are in accordance with the constant temperature Fermi gas model. From the spin distribution we have determined the corresponding spin cutoff parameter σ and compared it to the prediction from nuclear systematics

  7. Nuclear interactions of cosmic rays with the Mars atmosphere and rocks according to data of the Mars-5 space vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Surkov, Yu A; Moskaleva, L P; Kharyukova, V P; Borodin, A M [AN SSSR, Moscow. Inst. Geokhimii i Analiticheskoj Khimii

    1976-03-01

    Gamma-spectra of Mars have been analyzed measured by the ''Mars-5'' interplanetary station at the altitude of approximately 200 km over the planet. A model spectrum of the Mars atmosphere gamma-radiation obtained earlier has been employed for obtaining cosmo-chemical information of the Mars rocks. In the energy range of gamma radiation Esub(..gamma..)(>=)2.6 MeV, in which no contribution of gamma radiation of natural radioisotopes is present, the best agreement has been obtained for the spectrum of gamma-radiation induced by cosmic rays in rocks of the type of earthly basalts.

  8. Experimental Aspects of Nuclear Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Slaus, I. [Institute ' ' Rudjer Boskovic' ' , Zagreb, Yugoslavia (Croatia)

    1970-07-15

    1. Introduction; 2. Basic features of nuclear interaction; 3. How accurate is our present knowledge of phase parameters? 4. Experimental problems in N-N scattering studies; 5. N-N potential models; 6. Some open problems in nuclear interaction studies. (author)

  9. Nuclear Forensics using Gamma-ray Spectroscopy

    Directory of Open Access Journals (Sweden)

    Norman E. B.

    2016-01-01

    Full Text Available Much of George Dracoulis’s research career was devoted to utilising gamma-ray spectroscopy in fundamental studies in nuclear physics. This same technology is useful in a wide range of applications in the area of nuclear forensics. Over the last several years, our research group has made use of both high- and low-resolution gamma-ray spectrometers to: identify the first sample of plutonium large enough to be weighed; determine the yield of the Trinity nuclear explosion; measure fission fragment yields as a function of target nucleus and neutron energy; and observe fallout in the U. S. from the Fukushima nuclear reactor accident.

  10. Mutual control of X-rays and nuclear transitions

    Energy Technology Data Exchange (ETDEWEB)

    Gunst, Jonas Friedrich

    2015-12-14

    In the course of this Thesis the mutual control between X-rays and nuclear transitions is investigated theoretically. In the first Part, we study the nuclear photoexcitation with the highly brilliant and coherent X-ray free-electron lasers (XFELs). Apart from amplifying the direct resonant interaction with nuclear transitions, the super-intense XFEL can produce new states of matter like cold, high-density plasmas where secondary nuclear excitation channels may come into play, e.g., nuclear excitation by electron capture (NEEC). Our results predict that in the case of {sup 57}Fe targets secondary NEEC can be safely neglected, whereas it is surprisingly the dominating contribution (in comparison to the direct photoexcitation) for the XFEL-induced {sup 93m}Mo isomer triggering. Based on these case studies, we elaborate a general set of criteria to identify the prevailing excitation channel for a certain nuclear isotope. These criteria may be most relevant for future nuclear resonance experiments at XFEL facilities. On the opposite frontier, the interplay between single X-ray photons and nuclear transitions offer potential storage and processing applications for information science in their most compact form. In the second Part of this Thesis, we show that nuclear forward scattering off {sup 57}Fe targets can be employed to process polarization-encoded single X-rays via timed magnetic field rotations. Apart from the realization of logical gates with X-rays, the polarization encoding is used to design an X-ray quantum eraser scheme where the interference between scattering paths can be switched off and on in a controlled manner. Such setups may advance time-energy complementarity tests to so far unexplored parameter regimes, e.g., to the domain of X-ray quanta.

  11. Gamma-ray and electron spectroscopy in nuclear physics

    International Nuclear Information System (INIS)

    Ejiri, H.

    1989-01-01

    This book is devoted to the role of gamma-ray and conversion-electron (γ-e) spectroscopy in developing our understanding of nuclear structure and nuclear reaction-mechanisms. The book was written because of the spectacular development in the last decade of new γ-e spectroscopic methods, and their application to various kinds of nuclear reactions and the need to present γ-e spectroscopy from the point of view of nuclear structure as well as of reaction mechanism. The importance of γ-e spectroscopy is due to the simplicity and familiarity of the electromagnetic interaction, which gives accurate values for many nuclear quantities and reveals special nuclear properties. γ-e spectroscopy is applied to investigate static as well as dynamic nuclear properties over a wide range of excitation energies from the ground state to states of extreme temperatures and angular momentum, including some new degrees of freedom. (author)

  12. Quasiparticle interaction in nuclear matter

    International Nuclear Information System (INIS)

    Poggioli, R.S.; Jackson, A.D.

    1975-07-01

    A microscopic calculation of the quasiparticle interaction in nuclear matter is detailed. In order to take especial care of the contributions from the low momentum states, a model space is introduced. Excluded from the model space, the high momentum states are absorbed into the model interaction. Brueckner theory suggests the choice of a truncated G-matrix as a good approximation for this model interaction. A simple perturbative approach is attempted within the model space. The calculated quasiparticle interaction is consistent with experimental results. (11 tables, 14 figures)

  13. Gamma-Ray Interactions for Reachback Analysts

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Myers, Steven Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-02

    This presentation is a part of the DHS LSS spectroscopy training course and presents an overview of the following concepts: identification and measurement of gamma rays; use of gamma counts and energies in research. Understanding the basic physics of how gamma rays interact with matter can clarify how certain features in a spectrum were produced.

  14. Cosmic ray modulation and merged interaction regions

    International Nuclear Information System (INIS)

    Burlaga, L.F.; Goldstein, M.L.; Mcdonald, F.B.

    1985-01-01

    Beyond several AU, interactions among shocks and streams give rise to merged interaction regions in which the magnetic field is turbulent. The integral intensity of . 75 MeV/Nuc cosmic rays at Voyager is generally observed to decrease when a merged interaction region moves past the spacecraft and to increase during the passage of a rarefaction region. When the separation between interaction regions is relatively large, the cosmic ray intensity tends to increase on a scale of a few months. This was the case at Voyager 1 from July 1, 1983 to May 1, 1984, when the spacecraft moved from 16.7 to 19.6 AU. Changes in cosmic ray intensity were related to the magnetic field strength in a simple way. It is estimated that the diffusion coefficient in merged interaction regions at this distance is similar to 0.6 x 10 to the 22nd power sq cm/s

  15. X- rays and matter- the basic interactions

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens

    2008-01-01

    In this introductory article we attempt to provide the theoretical basis for developing the interaction between X-rays and matter, so that one can unravel properties of matter by interpretation of X-ray experiments on samples. We emphasize that we are dealing with the basics, which means that we...... shall limit ourselves to a discussion of the interaction of an X-ray photon with an isolated atom, or rather with a single electron in a Hartree-Fock atom. Subsequent articles in this issue deal with more complicated - and interesting - forms of matter encompassing many atoms or molecules. To cite...

  16. Nuclear beta decay and the weak interaction

    International Nuclear Information System (INIS)

    Kean, D.C.

    1975-11-01

    Short notes are presented on various aspects of nuclear beta decay and weak interactions including: super-allowed transitions, parity violation, interaction strengths, coupling constants, and the current-current formalism of weak interaction. (R.L.)

  17. Nuclear interactions and hadronic matter

    International Nuclear Information System (INIS)

    Petrovici, Mihai; Pop, Amalia; Stoicea, Gabriel; Berceanu, Ionela; Moisa, Dorin; Petris, Mariana; Simion, Victor; Aiftimiei, Cristina; Cruceru, Ilie; Ciobanu, Mircea; Catanescu, Vasile; Caragheorgheopol; Gheorghe

    2002-01-01

    The new generation of heavy ion accelerators and complex experimental devices, developed in the last two decades, give access to new information concerning the dynamics of nuclear collisions and allow to obtain and study in the laboratory the nuclear matter under extreme conditions of density and temperature. Of special interest is the intermediate energy region where the reactions are dominated by the competition between the mean field and nucleon-nucleon interaction. Fundamental aspects of nuclear reaction studies are probed at different instants of a nuclear collision. One can learn about the transport properties of nuclear matter in pure nucleonic regime and understand the modification of the nucleon-nucleon cross section due to various in-medium effects: density effects, effective mass, quantum effects, three-body interactions. With increasing energy, fast particle emission associated with direct nucleon-nucleon collisions in the first steps of the reaction come into play too. At higher energy, flow measurements are crucial tests of the influence of medium effects by probing the elastic part of the nucleon-nucleon collisions. On the other side, at higher incident energies, the characteristics of the nuclear equation of state (EoS) can be studied if local thermal and chemical equilibrium turns out to be established. Understanding of the properties of the nuclear matter in extreme conditions is a fundamental goal. The EoS is also an essential ingredient in the description of the massive stars leading to supernova explosion and neutron star formation. Experimental studies of such aspects needs experimental devices of high complexity which can detect and identify event by event all products coming out from heavy ion interactions at intermediate, relativistic and ultra-relativistic energies, having as complete as possible information on their mass, charge, velocity vector. CHIMERA and FOPI are such devices for intermediate and relativistic energy, respectively. Our

  18. Hyperon interactions in nuclear matter

    Energy Technology Data Exchange (ETDEWEB)

    Dhar, Madhumita; Lenske, Horst [Institut fuer Theoretische Physik, Universitaet Giessen (Germany)

    2014-07-01

    Baryon-baryon interactions within the SU(3)-octet are investigated in free space and nuclear matter. A meson exchange model is used for determining the interaction. The Bethe-Salpeter equations are solved in a 3-D reduction scheme. In-medium effects have been incorporated by including a two particle Pauli projection operator in the scattering equation. The coupling of the various channels of total strangeness S=-1,-2 and conserved total charge is studied in detail. Calculations and the corresponding results are compared for using the isospin and the particle basis. Matrix elements are compared in detail, in particular discussing mixing effects of different hyperon channels. Special attention is paid to the physical thresholds. The density dependence of interaction is clearly seen in the variation of the in-medium low-energy parameters. The approach is compared to descriptions derived from chiral-EFT and other meson-exchange models e.g. the Nijmegen and the Juelich model.

  19. Cosmic Ray Interactions in Shielding Materials

    International Nuclear Information System (INIS)

    Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Ankney, Austin S.; Orrell, John L.; Berguson, Timothy J.; Troy, Meredith D.

    2011-01-01

    This document provides a detailed study of materials used to shield against the hadronic particles from cosmic ray showers at Earth's surface. This work was motivated by the need for a shield that minimizes activation of the enriched germanium during transport for the MAJORANA collaboration. The materials suitable for cosmic-ray shield design are materials such as lead and iron that will stop the primary protons, and materials like polyethylene, borated polyethylene, concrete and water that will stop the induced neutrons. The interaction of the different cosmic-ray components at ground level (protons, neutrons, muons) with their wide energy range (from kilo-electron volts to giga-electron volts) is a complex calculation. Monte Carlo calculations have proven to be a suitable tool for the simulation of nucleon transport, including hadron interactions and radioactive isotope production. The industry standard Monte Carlo simulation tool, Geant4, was used for this study. The result of this study is the assertion that activation at Earth's surface is a result of the neutronic and protonic components of the cosmic-ray shower. The best material to shield against these cosmic-ray components is iron, which has the best combination of primary shielding and minimal secondary neutron production.

  20. Nuclear Physics Meets the Sources of the Ultra-High Energy Cosmic Rays.

    Science.gov (United States)

    Boncioli, Denise; Fedynitch, Anatoli; Winter, Walter

    2017-07-07

    The determination of the injection composition of cosmic ray nuclei within astrophysical sources requires sufficiently accurate descriptions of the source physics and the propagation - apart from controlling astrophysical uncertainties. We therefore study the implications of nuclear data and models for cosmic ray astrophysics, which involves the photo-disintegration of nuclei up to iron in astrophysical environments. We demonstrate that the impact of nuclear model uncertainties is potentially larger in environments with non-thermal radiation fields than in the cosmic microwave background. We also study the impact of nuclear models on the nuclear cascade in a gamma-ray burst radiation field, simulated at a level of complexity comparable to the most precise cosmic ray propagation code. We conclude with an isotope chart describing which information is in principle necessary to describe nuclear interactions in cosmic ray sources and propagation.

  1. Gamma ray thermometrical facility for nuclear reactor

    International Nuclear Information System (INIS)

    Smith, R.D.; Regazzoni, Pierre.

    1981-01-01

    This invention concerns a gamma ray thermometer for nuclear reactors, fitted with a thermal bridge for use as a centring device. In accordance with the invention, an elastic device fills all the annular space between the gamma thermometer and the orifice through which the thermometer is introduced. This elastic device has the two-fold role of providing a thermal bridge at the gamma thermometer location suitable as a heat well, and of acting as a device for centring the thermometer in the orifice into which it has been introduced [fr

  2. Nuclear reaction inputs based on effective interactions

    Energy Technology Data Exchange (ETDEWEB)

    Hilaire, S.; Peru, S.; Dubray, N.; Dupuis, M.; Bauge, E. [CEA, DAM, DIF, Arpajon (France); Goriely, S. [Universite Libre de Bruxelles, Institut d' Astronomie et d' Astrophysique, CP-226, Brussels (Belgium)

    2016-11-15

    Extensive nuclear structure studies have been performed for decades using effective interactions as sole input. They have shown a remarkable ability to describe rather accurately many types of nuclear properties. In the early 2000 s, a major effort has been engaged to produce nuclear reaction input data out of the Gogny interaction, in order to challenge its quality also with respect to nuclear reaction observables. The status of this project, well advanced today thanks to the use of modern computers as well as modern nuclear reaction codes, is reviewed and future developments are discussed. (orig.)

  3. Pair production from nuclear collisions and cosmic ray transport

    International Nuclear Information System (INIS)

    Norbury, John W

    2006-01-01

    Modern cosmic ray transport codes, that are capable of use for a variety of applications, need to include all significant atomic, nuclear and particle reactions at a variety of energies. Lepton pair production from nucleus-nucleus collisions has not been included in transport codes to date. Using the methods of Baur, Bertulani and Baron, the present report provides estimates of electron-positron pair production cross sections for nuclei and energies relevant to cosmic ray transport. It is shown that the cross sections are large compared to other typical processes such as single neutron removal due to strong or electromagnetic interactions. Therefore, lepton pair production may need to be included in some transport code applications involving MeV electrons. (brief report)

  4. Nuclear physics and fundamental interactions

    International Nuclear Information System (INIS)

    Krmpotic, K.

    1980-01-01

    In this work, it is discussed strong, weak and electromagnetic interactions. By means of experiments and theoretical interpretation of these interactions it was possible to interpret important properties, which will be discussed here. (A.C.A.S.) [pt

  5. Symmetric nuclear matter with Skyrme interaction

    International Nuclear Information System (INIS)

    Manisa, K.; Bicer, A.; Atav, U.

    2010-01-01

    The equation of state (EOS) and some properties of symmetric nuclear matter, such as the saturation density, saturation energy and incompressibility, are obtained by using Skyrme's density-dependent effective nucleon-nucleon interaction.

  6. Robust ray-tracing algorithms for interactive dose rate evaluation

    International Nuclear Information System (INIS)

    Perrotte, L.

    2011-01-01

    More than ever, it is essential today to develop simulation tools to rapidly evaluate the dose rate received by operators working on nuclear sites. In order to easily study numerous different scenarios of intervention, computation times of available softwares have to be all lowered. This mainly implies to accelerate the geometrical computations needed for the dose rate evaluation. These computations consist in finding and sorting the whole list of intersections between a big 3D scene and multiple groups of 'radiative' rays meeting at the point where the dose has to be measured. In order to perform all these computations in less than a second, we first propose a GPU algorithm that enables the efficient management of one big group of coherent rays. Then we present a modification of this algorithm that guarantees the robustness of the ray-triangle intersection tests through the elimination of the precision issues due to floating-point arithmetic. This modification does not require the definition of scene-dependent coefficients ('epsilon' style) and only implies a small loss of performance (less than 10%). Finally we propose an efficient strategy to handle multiple ray groups (corresponding to multiple radiative objects) which use the previous results.Thanks to these improvements, we are able to perform an interactive and robust dose rate evaluation on big 3D scenes: all of the intersections (more than 13 million) between 700 000 triangles and 12 groups of 100 000 rays each are found, sorted along each ray and transferred to the CPU in 470 milliseconds. (author) [fr

  7. Realistic effective interactions for nuclear systems

    International Nuclear Information System (INIS)

    Hjort-Jensen, M.; Osnes, E.; Kuo, T.T.S.

    1994-09-01

    A review of perturbative many-body descriptions of several nuclear systems is presented. Symmetric and asymmetric nuclear matter and finite nuclei with few valence particles are examples of systems considered. The many-body description starts with the most recent meson-exchange potential models for the nucleon-nucleon interaction, an interaction which in turn is used in perturbative schemes to evaluate the effective interaction for finite nuclei and infinite nuclear matter. A unified perturbative approach based on time-dependent perturbation theory is elaborated. For finite nuclei new results are presented for the effective interaction and the energy spectra in the mass areas of oxygen, calcium and tin. 166 refs., 83 refs., 21 tabs

  8. K-ray nuclear densitometer at PETRONAS Carigali

    International Nuclear Information System (INIS)

    Zainudin Othman

    1985-01-01

    The hydrology and tracer studies Group of Nuclear Energy Unit was requested to overcome the calibration problems of nuclear density gauges which was installed at the condensate - natural gas pipeline at the PETRONAS Carigali in Kerteh, Trengganu in February 1984. The roles and application of k-ray nuclear densitometer are included. Similar activities have also been performed by the Unit to promote the application at nuclear techniques in local industries. (A.J.)

  9. Weak interaction studies from nuclear beta decay

    International Nuclear Information System (INIS)

    Morita, M.

    1981-01-01

    The studies performed at the theoretical nuclear physics division of the Laboratory of Nuclear Studies, Osaka University, are reported. Electron spin density and internal conversion process, nuclear excitation by electron transition, beta decay, weak charged current, and beta-ray angular distributions in oriented nuclei have been studied. The relative intensity of internal conversion electrons for the case in which the radial wave functions of orbital electrons are different for electron spin up and down was calculated. The calculated value was in good agreement with the experimental one. The nuclear excitation following the transition of orbital electrons was studied. The calculated probability of the nuclear excitation of Os 189 was 1.4 x 10 - 7 in conformity with the experimental value 1.7 x 10 - 7 . The second class current and other problems on beta-decay have been extensively studied, and described elsewhere. Concerning weak charged current, the effects of all induced terms, the time component of main axial vector, all partial waves of leptons, Coulomb correction for the electrons in finite size nuclei, and radiative correction were studied. The beta-ray angular distribution for the 1 + -- 0 + transition in oriented B 12 and N 12 was investigated. In this connection, investigation on the weak magnetism to include all higher order corrections for the evaluation of the spectral shape factors was performed. Other works carried out by the author and his collaborators are also explained. (Kato, T.)

  10. Hadronic and nuclear interactions in QCD

    International Nuclear Information System (INIS)

    1982-01-01

    Despite the evidence that QCD - or something close to it - gives a correct description of the structure of hadrons and their interactions, it seems paradoxical that the theory has thus far had very little impact in nuclear physics. One reason for this is that the application of QCD to distances larger than 1 fm involves coherent, non-perturbative dynamics which is beyond present calculational techniques. For example, in QCD the nuclear force can evidently be ascribed to quark interchange and gluon exchange processes. These, however, are as complicated to analyze from a fundamental point of view as is the analogous covalent bond in molecular physics. Since a detailed description of quark-quark interactions and the structure of hadronic wavefunctions is not yet well-understood in QCD, it is evident that a quantitative first-principle description of the nuclear force will require a great deal of theoretical effort. Another reason for the limited impact of QCD in nuclear physics has been the conventional assumption that nuclear interactions can for the most part be analyzed in terms of an effective meson-nucleon field theory or potential model in isolation from the details of short distance quark and gluon structure of hadrons. These lectures, argue that this view is untenable: in fact, there is no correspondence principle which yields traditional nuclear physics as a rigorous large-distance or non-relativistic limit of QCD dynamics. On the other hand, the distinctions between standard nuclear physics dynamics and QCD at nuclear dimensions are extremely interesting and illuminating for both particle and nuclear physics

  11. Hyperfine interactions measured by nuclear orientation technique

    International Nuclear Information System (INIS)

    Brenier, R.

    1982-01-01

    This report concerns the use of hyperfine interaction to magnetism measurements and to the determination of the nuclear structure of Terbium isotopes by the low temperature nuclear orientation technique. In the first part we show that the rhodium atom does not support any localized moment in the chromium matrix. The hyperfine magnetic field at the rhodium nuclear site follows the Overhauser distribution, and the external applied magnetic field supports a negative Knight shift of 16%. In the second part we consider the structure of neutron deficient Terbium isotopes. We introduce a coherent way of evaluation and elaborate a new nuclear thermometer. The magnetic moments allows to strike on the studied states configuration. The analysis of our results shows a decrease of the nuclear deformation for the lighter isotopes [fr

  12. QCD Structure of Nuclear Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Granados, Carlos [Florida Intl Univ., Miami, FL (United States)

    2011-05-25

    This dissertation investigated selected processes involving baryons and nuclei in hard scattering reactions. Through these processes, this work explored the constituent structure of baryons and the mechanisms through which the interactions between these constituents ultimately control the selected reactions. First, hard nucleon-nucleon elastic scattering was studied considering the quark exchange (QE) between the nucleons to be the dominant mechanism of interaction in the constituent picture. It was found that an angular asymmetry exhibited by proton-neutron (pn) elastic scattering data is explained within this framework if a quark-diquark picture dominates the nucleon's structure instead of a more traditional SU(6) model. The latter yields an asymmetry around 90 deg center of mass scattering with a sign opposite to what is experimentally observed. The second process is the hard breakup by a photon of a nucleon-nucleon system in light nuclei. Proton-proton (pp) and pn breakup in 3He, and double Δ-isobars production in deuteron breakup were analyzed in the hard rescattering model (HRM), which in conjunction with the QE mechanism provides a QCD description of the reaction. Cross sections for both channels in 3He photodisintegration were computed without the need of a fitting parameter. The results presented here for pp breakup show excellent agreement with recent experimental data. In double Δ-isobars production in deuteron breakup, HRM angular distributions for the two double Δ channels were compared to the pn channel and to each other. An important prediction from this study is that the Δ++ Δ- channel consistently dominates Δ+Δ0, which is in contrast with models that unlike the HRM consider a double Δ system in the initial state of the interaction. For such models both channels should have the same strength.

  13. Precision linac and laser technologies for nuclear photonics gamma-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Albert, F.; Hartemann, F. V.; Anderson, S. G.; Cross, R. R.; Gibson, D. J.; Hall, J.; Marsh, R. A.; Messerly, M.; Wu, S. S.; Siders, C. W.; Barty, C. P. J. [Lawrence Livermore National Laboratory, NIF and Photon Science, 7000 East Avenue, Livermore, California 94550 (United States)

    2012-05-15

    Tunable, high precision gamma-ray sources are under development to enable nuclear photonics, an emerging field of research. This paper focuses on the technological and theoretical challenges related to precision Compton scattering gamma-ray sources. In this scheme, incident laser photons are scattered and Doppler upshifted by a high brightness electron beam to generate tunable and highly collimated gamma-ray pulses. The electron and laser beam parameters can be optimized to achieve the spectral brightness and narrow bandwidth required by nuclear photonics applications. A description of the design of the next generation precision gamma-ray source currently under construction at Lawrence Livermore National Laboratory is presented, along with the underlying motivations. Within this context, high-gradient X-band technology, used in conjunction with fiber-based photocathode drive laser and diode pumped solid-state interaction laser technologies, will be shown to offer optimal performance for high gamma-ray spectral flux, narrow bandwidth applications.

  14. Nuclear and x-ray spectroscopy with radioactive sources

    International Nuclear Information System (INIS)

    Fink, R.W.

    1977-01-01

    Research in nuclear chemistry for 1977 is reviewed. The greatest part of the effort was directed to nuclear spectroscopy (systematics, models, experimental studies), but some work was also done involving fast neutrons and x rays from radioactive sources. Isotopes of Tl, Hg, Au, and Eu were studied in particular. Personnel and publications lists are also included. 5 figures, 1 table

  15. Direct interaction in nuclear reactions: a theory

    International Nuclear Information System (INIS)

    Dominicis, C.T. de

    1959-01-01

    General treatment of the foundations of direct interaction in nuclear reactions; representation of the instantaneous elastic scattering amplitude by the scattering amplitude due to a complex potential; expansion of the instantaneous inelastic scattering amplitude and discussion of the 1. Bohr approximation (distorted waves) contribution to individual and collective states of excitation. (author) [fr

  16. Study of X-rays and nuclear gamma -rays in muonic thallium

    CERN Document Server

    Backe, H; Jahnke, U; Kankeleit, E; Pearce, R M; Petitjean, C; Schellenberg, L; Schneuwly, H; Schröder, W U; Walter, H K; Zehnder, A

    1972-01-01

    Energies and intensities of muonic X-rays, nuclear gamma -rays and mu -capture gamma -rays were measured in natural muonic thallium with Ge (Li) detectors. The absolute intensities of higher mu X-rays were reproduced by a cascade calculation starting with a statistical population at n=20 including K-, L- and M-conversion. The electron screening effect was deduced from energies of higher mu X-rays. Eight prompt nuclear gamma -rays were found. This excitation explains the anomalous intensity ratios of the 2p-1s and 3d-2p fine structure components. From the nuclear gamma -rays of the first excited states were deduced: the magnetic h.f. splittings, muonic isomer shifts E2/M1 mixing ratios and the half-life in the presence of the muon in /sup 205/Tl. Evidence for a magnetic nuclear polarization was found. An isotope shift of Delta E=10.35+or-0.25 keV was measured for the 1s/sub 1/2/ state which is compared with data from optical spectroscopy. From an analysis of the time distribution of delayed gamma -rays from mu...

  17. Cosmic ray nuclei detection in the balloon borne nuclear emulsion gamma ray telescope flight in Australia (GRAINE 2015

    Directory of Open Access Journals (Sweden)

    Iyono Atsushi

    2017-01-01

    Full Text Available Nuclear emulsion plates for studying elementary particle physics as well as cosmic ray physics are very powerful tracking tools with sub-micron spatial resolutions of charged particle trajectories. Even if gamma rays have to be detected, electron-positron pair tracks can provide precise information to reconstruct their direction and energy with high accuracy. Recent developments of emulsion analysis technology can digitally handle almost all tracks recorded in emulsion plates by using the Hyper Track Selector of the OPERA group at NAGOYA University. On the other hand, the potential of time resolutions have been equipped by emulsion multilayer shifter technology in the GRAINE (Gamma Ray Astro-Imager with Nuclear Emulsion experiments, the aims of which are to detect cosmic gamma rays such as the Vela pulsar stellar object by precise emulsion tracking analysis and to study cosmic ray particle interactions and chemical compositions. In this paper, we focus on the subject of cosmic ray nuclei detection in the GRAINE balloon flight experiments launched at Alice Springs, Australia in May 2015.

  18. Nuclear interactive evaluations on distributed processors

    International Nuclear Information System (INIS)

    Dix, G.E.; Congdon, S.P.

    1988-01-01

    BWR [boiling water reactor] nuclear design is a complicated process, involving trade-offs among a variety of conflicting objectives. Complex computer calculations and usually required for each design iteration. GE Nuclear Energy has implemented a system where the evaluations are performed interactively on a large number of small microcomputers. This approach minimizes the time it takes to carry out design iterations even through the processor speeds are low compared with modern super computers. All of the desktop microcomputers are linked to a common data base via an ethernet communications system so that design data can be shared and data quality can be maintained

  19. Nuclear quadrupole deformations and anisotropic angular correlations between K x rays and gamma rays

    International Nuclear Information System (INIS)

    Khalil, A.E.

    1983-01-01

    Anisotropic angular correlation between gamma rays and the K x rays following the K conversion from nuclei with large static deformations has been studied. A complete theoretical expression for 181 Ta, the second known case of this phenomenon, is presented. This case involves several mixed nuclear transitions which result in 62% of the x rays arising from magnetic dipole internal-conversion processes and 38% arising from electric-quadrupole internal-conversion processes

  20. Are there nuclear contributions to gamma ray burst spectra

    International Nuclear Information System (INIS)

    Matz, S.M.; Chupp, E.L.; Forrest, D.J.; Share, G.H.; Nolan, P.L.; Rieger, E.

    1984-01-01

    We have examined the spectra of 38 γ-ray bursts observed by the Gamma Ray Spectrometer (GRS) on the Solar Maximum Mission (SMM) satellite for evidence of a nuclear contribution to the high energy flux. A sum of spectra from the nine bursts with detectable flux >4 MeV suggests but does not require a drop-off above 7 MeV. A cutoff between 7 and 8 MeV is consistent with a high energy spectrum dominated by nuclear lines

  1. Nuclear structure considerations for gamma-ray lasers

    International Nuclear Information System (INIS)

    Strottman, D.; Arthur, E.D.; Madland, D.G.

    1985-01-01

    Presented are initial results in our investigation of the nuclear physics issues of gamma-ray lasers. These include the questions of what is known from existing experimental data, where does one optimally search for nuclei displaying simultaneously both closely lying levels and nuclear isomerism, and which theoretical models does one employ for systematic searches for candidate nuclei and for calculation of detailed candidate level properties

  2. Nuclear structure and neutrino-nucleus interaction

    International Nuclear Information System (INIS)

    Krmpotic, Francisco

    2011-01-01

    Recent years have witnessed an intense experimental and theoretical activity oriented towards a better comprehension of neutrino nucleus interaction. While the main motivation for this task is the demand coming from oscillation experiments in their search for a precise determination of neutrino properties, the relevance of neutrino interaction with matter is more wide-ranging. It is imperative for astrophysics, hadronic and nuclear physics, and physics beyond the standard model. The experimental information on neutrino induced reactions is rapidly growing, and the corresponding theoretical description is a challenging proposition, since the energy scales of interest span a vast region, going from few MeV for solar neutrinos, to tens of MeV for the interpretation of experiments with the muon and pion decay at rest and the detection of neutrinos coming from the core collapse of supernova, and to hundreds of MeV or few GeV for the detection of atmospheric neutrinos, and for the neutrino oscillation program of the MiniBooNE experiment. The presence of neutrinos, being chargeless particles, can only be inferred by detecting the secondary particles created in colliding and interacting with the matter. Nuclei are often used as neutrino detectors, and in particular 12 C which is a component of many scintillator detectors. Thus, the interpretation of neutrino data heavily relies on detailed and quantitative knowledge of the features of the neutrino-nucleus interaction. The nuclear structure methods used in the evaluation of the neutrino-nucleus cross section are reviewed. Detailed comparison between the experimental and theoretical results establishes benchmarks needed for verification and/or parameter adjustment of the nuclear models. Having a reliable tool for such calculation is of great importance in a variety of applications, such as the description of the r-process nucleosynthesis. (author)

  3. Nuclear spallation of cosmic ray nuclei in the interstellar medium

    International Nuclear Information System (INIS)

    Raisbeck, G.

    1974-01-01

    Nuclear spallation of cosmic rays during propagation is qualitatively reviewed. After the problem is defined, a discussion is presented of the relevant information obtainable from studying nuclear reactions, specifically, quantity and distribution of traversed matter, time and place of propagation, and source composition. Comments are offered on the cross sections and nuclear reactions that are critical for a complete understanding in this area. This is followed by a brief look at the present status of research and possibilities for further work using the Bevalac. (U.S.)

  4. Muon Production in Relativistic Cosmic-Ray Interactions

    OpenAIRE

    Klein, Spencer

    2009-01-01

    Cosmic-rays with energies up to $3\\times10^{20}$ eV have been observed. The nuclear composition of these cosmic rays is unknown but if the incident nuclei are protons then the corresponding center of mass energy is $\\sqrt{s_{nn}} = 700$ TeV. High energy muons can be used to probe the composition of these incident nuclei. The energy spectra of high-energy ($>$ 1 TeV) cosmic ray induced muons have been measured with deep underground or under-ice detectors. These muons come from pion and kaon de...

  5. On sensitivity of gamma families to the model of nuclear interaction

    International Nuclear Information System (INIS)

    Krys, A.; Tomaszewski, A.; Wrotniak, J.A.

    1980-01-01

    A variety of 5 different models of nuclear interaction has been used in a Monte Carlo simulation of nuclear and electromagnetic showers in the atmosphere. The gamma families obtained from this simulation were processed in a way, analogous to one employed in analysis of Pamir experimental results. The sensitivity of observed pattern to the nuclear interaction model assumptions was investigated. Such sensitivity, though not a strong one, was found. In case of longitudinal (or energetical) family characteristics, the changes in nuclear interaction should be really large, if they were to be reflected in the experimental data -with all methodical error possibilities. The transverse characteristics of gamma families are more sensitive to the assumed transverse momentum distribution, but they feel the longitudinal features of nuclear interaction as well. Additionally, there was tested the dependence of observed family pattern on some methodical effects (resolving power of X-ray film, radial cut-off and energy underestimation.) (author)

  6. Workshop on Hadron-Hadron & Cosmic-Ray Interactions at multi-TeV Energies

    CERN Document Server

    Alessandro, B; Bergman, D; Bongi, M; Bunyatyan, A; Cazon, L; d'Enterria, D; de Mitri, I; Doll, P; Engel, R; Eggert, K; Garzelli, M; Gerhardt, L; Gieseke, S; Godbole, R; Grosse-Oetringhaus, J F; Gustafson, G; Hebbeker, T; Kheyn, L; Kiryluk, J; Lipari, P; Ostapchenko, S; Pierog, T; Piskounova, O; Ranft, J; Rezaeian, A; Rostovtsev, A; Sakurai, N; Sapeta, S; Schleich, S; Schulz, H; Sjostrand, T; Sonnenschein, L; Sutton, M; Ulrich, R; Werner, K; Zapp, K; CRLHC10; CRLHC 10

    2011-01-01

    The workshop on "Hadron-Hadron and Cosmic-Ray Interactions at multi-TeV Energies" held at the ECT* centre (Trento) in Nov.-Dec. 2010 gathered together both theorists and experimentalists to discuss issues of the physics of high-energy hadronic interactions of common interest for the particle, nuclear and cosmic-ray communities. QCD results from collider experiments -- mostly from the LHC but also from the Tevatron, RHIC and HERA -- were discussed and compared to various hadronic Monte Carlo generators, aiming at an improvement of our theoretical understanding of soft, semi-hard and hard parton dynamics. The latest cosmic-ray results from various ground-based observatories were also presented with an emphasis on the phenomenological modeling of the first hadronic interactions of the extended air-showers generated in the Earth atmosphere. These mini-proceedings consist of an introduction and short summaries of the talks presented at the meeting.

  7. X-ray diagnostics for laser matter interaction experiments

    International Nuclear Information System (INIS)

    Troussel, Ph.

    2000-01-01

    Advances in the field of laser-driven inertially confined thermonuclear fusion research since the early 1990's are reviewed. It covers the experimental techniques used to study the interaction of laser radiation with matter and high density plasma. A high performance instrumentation (diagnostics) for observation of X radiation (from a few eV to a few keV) will be required to understand the physical processes involved in the interaction. This paper is a three-part: first part, describes diagnostics metrology realized around different X-ray sources (synchrotron, laser plasma...); a second part, synthesizes theoretical and experimental X-ray optics studies and show the interest for direct applications as X-ray spectroscopy and X-ray imaging around laser-produced plasma; a third part, is a review of high resolution X-ray imaging, performances of these optical system were summarized. (author)

  8. Nuclear gamma ray lines from supernovae

    International Nuclear Information System (INIS)

    Jardim, J.O.D.

    1980-01-01

    From theoretical considerations of the behaviour of gamma ray line fluxes occurring after a supernova explosion, the 1.156 and 0.847 MeV lines are seen to be the most likely to be observed. The 1.156 MeV line has been previously observed by other investigators. Observations of the 0.847 MeV line, and 1.332, 1.173 and 0.059 MeV lines using a Ge(Li) telescope aboard a stratospheric balloon which was flown in Brazil in 1977 are reported. The observation using a NaI(Tl) detector of a line in the energy interval 1.5 - 1.6 MeV, which may be due to 0 18 (p,p') 0 18 sup (*) reaction is also reported. (Author) [pt

  9. γ-ray shielding behaviors of some nuclear engineering materials

    International Nuclear Information System (INIS)

    Mann, Kulwinder Singh

    2017-01-01

    The essential requirement of a material to be used for engineering purposes at nuclear establishments is its ability to attenuate the most penetrating ionizing radiations, gamma (γ)-rays. Mostly, high-Z materials such as heavy concrete, lead, mercury, and their mixtures or alloys have been used in the construction of nuclear establishments and thus termed as nuclear engineering materials (NEM). The NEM are classified into two categories, namely opaque and transparent, depending on their behavior towards the visible spectrum of EM waves. The majority of NEM are opaque. By contrast, various types of glass, which are transparent to visible light, are necessary at certain places in the nuclear establishments. In the present study, γ-ray shielding behaviors (GSB) of six glass samples (transparent NEM) were evaluated and compared with some opaque NEM in a wide range of energy (15 keV–15 MeV) and optical thickness (OT). The study was performed by computing various γ-ray shielding parameters (GSP) such as the mass attenuation coefficient, equivalent atomic number, and buildup factor. A self-designed and validated computer-program, the buildup factor-tool, was used for various computations. It has been established that some glass samples show good GSB, thus can safely be used in the construction of nuclear establishments in conjunction with the opaque NEM as well

  10. γ-ray shielding behaviors of some nuclear engineering materials

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Kulwinder Singh [Dept. of Physics, D.A.V. College, Punjab (India)

    2017-06-15

    The essential requirement of a material to be used for engineering purposes at nuclear establishments is its ability to attenuate the most penetrating ionizing radiations, gamma (γ)-rays. Mostly, high-Z materials such as heavy concrete, lead, mercury, and their mixtures or alloys have been used in the construction of nuclear establishments and thus termed as nuclear engineering materials (NEM). The NEM are classified into two categories, namely opaque and transparent, depending on their behavior towards the visible spectrum of EM waves. The majority of NEM are opaque. By contrast, various types of glass, which are transparent to visible light, are necessary at certain places in the nuclear establishments. In the present study, γ-ray shielding behaviors (GSB) of six glass samples (transparent NEM) were evaluated and compared with some opaque NEM in a wide range of energy (15 keV–15 MeV) and optical thickness (OT). The study was performed by computing various γ-ray shielding parameters (GSP) such as the mass attenuation coefficient, equivalent atomic number, and buildup factor. A self-designed and validated computer-program, the buildup factor-tool, was used for various computations. It has been established that some glass samples show good GSB, thus can safely be used in the construction of nuclear establishments in conjunction with the opaque NEM as well.

  11. γ-Ray Shielding Behaviors of Some Nuclear Engineering Materials

    Directory of Open Access Journals (Sweden)

    Kulwinder Singh Mann

    2017-06-01

    Full Text Available The essential requirement of a material to be used for engineering purposes at nuclear establishments is its ability to attenuate the most penetrating ionizing radiations, gamma (γ-rays. Mostly, high-Z materials such as heavy concrete, lead, mercury, and their mixtures or alloys have been used in the construction of nuclear establishments and thus termed as nuclear engineering materials (NEM. The NEM are classified into two categories, namely opaque and transparent, depending on their behavior towards the visible spectrum of EM waves. The majority of NEM are opaque. By contrast, various types of glass, which are transparent to visible light, are necessary at certain places in the nuclear establishments. In the present study, γ-ray shielding behaviors (GSB of six glass samples (transparent NEM were evaluated and compared with some opaque NEM in a wide range of energy (15 keV–15 MeV and optical thickness (OT. The study was performed by computing various γ-ray shielding parameters (GSP such as the mass attenuation coefficient, equivalent atomic number, and buildup factor. A self-designed and validated computer-program, the buildup factor-tool, was used for various computations. It has been established that some glass samples show good GSB, thus can safely be used in the construction of nuclear establishments in conjunction with the opaque NEM as well.

  12. A mobile gamma ray spectrometer system for nuclear hazard mapping

    CERN Document Server

    Smethurst, M A

    2000-01-01

    The Geological Survey of Norway has developed a system for mobile gamma ray spectrometer surveying suitable for use in nuclear emergencies where potentially dangerous radioactive materials have been released into the environment. The measuring system has been designed for use with different kinds of transportation platforms. These include fixed-wing aircraft, helicopters and vans. The choice of transportation platform depends on the nature of the nuclear emergency. Widespread fallout from a distant source can be mapped quickly from the air while local sources of radiation can be delineated by a car-borne system. The measuring system processes gamma ray spectra in real time. The operator of the system is therefore able to guide surveying in accordance with meaningful data values and immediately report these values to decision making The operator is presented with a number of different displays suited to different kinds of nuclear emergencies that lead to more efficient surveying. Real time processing of data m...

  13. Simulation of cosmic ray interaction at Saturne

    International Nuclear Information System (INIS)

    Michel, R.

    1996-01-01

    Accelerator experiments provide the basis for the development of physical models describing the production of cosmogenic nuclides by cosmic ray particles. Here, experiments are presented by which the irradiation of stony and iron meteoroids in space by galactic cosmic ray protons was successfully simulated; two thick spherical targets made of gabbro and of steel with radii of 25 and 10 cm, respectively, were isotropically irradiated with 1.6 GeV protons at LNS. The artificial meteoroids contained large numbers of individual small targets of up to 27 elements in which the depth-dependent production of radioactive and stable nuclides was analyzed by model calculations based on depth-dependent spectra of primary and secondary particles calculated by the HERMES code system and on experimental and theoretical thin-target cross sections. Due to the results of the two simulation experiments at LNS a consistent modelling of cosmogenic nuclide production rates in stony and iron meteorites was achieved for the first time which allows to interpret the observed abundances of cosmogenic nuclides in stony and iron meteorites with respect to their exposure histories and to describe the history of the cosmic radiation itself. (author)

  14. Proton-neutron interaction and nuclear structure

    International Nuclear Information System (INIS)

    Casten, R.F.

    1986-01-01

    The pervasive role of the proton-neutron interaction in nuclear structure is discussed. Particular emphasis is given to its influence on the onset of collectivity and deformation, on intruder states, and on the evolution of subshell structure. The N/sub p/N/sub n/ scheme is outlined and some applications of it to collective model calculations and to nuclei far off stability are described. The concept of N/sub p/N/sub n/ multiplets is introduced. 32 refs., 20 figs

  15. X-ray cinematography on the nuclear fuel and cladding motion diagnostics

    International Nuclear Information System (INIS)

    Mizuta, Hiroshi; Uruwashi, Shinichi.

    1979-01-01

    X-ray cinematography has been used for monitoring fuel motion in the out-of-pile fuel pin joule melting experiments for nuclear, liquid metal cooled fast breeder reactor, safety studies related to fuel pin failure, initial fuel motion and thermal fuel-coolant interaction (FCI) of the hypothetical core distractive accident. In order to visually observe the nuclear fuel motion, the X-ray cinematography system consists of an X-ray source located about 5 cm from the test section and an image intensifier located at a corresponding position on the opposite side of the test section. The image from the image intensifier has been recorded both with a high speed camera and video recorder. (author)

  16. Intensities and strong interaction attenuation of kaonic x-rays

    CERN Document Server

    Backenstoss, Gerhard; Koch, H; Povel, H P; Schwitter, A; Tauscher, Ludwig

    1974-01-01

    Relative intensities of numerous kaonic X-ray transitions have been measured for the elements C, P, S, and Cl, from which level widths due to the strong K-nucleus absorption have been determined. From these and earlier published data, optical potential parameters have been derived and possible consequences on the nuclear matter distribution are discussed. (10 refs).

  17. Neutrino neutral current interactions in nuclear matter

    International Nuclear Information System (INIS)

    Horowitz, C.J.; Wehrberger, K.

    1991-01-01

    Detailed knowledge of neutrino transport properties in matter is crucial for an understanding of the evolution of supernovae and of neutron star cooling. We investigate screening of neutrino scattering from a dense degenerate gas of electrons, protons and neutrons. We take into account correlations induced by the Coulomb interactions of the electrons and protons, and the strong interactions of the protons and neutrons. Nuclear matter is described by the σω model of quantum hadrodynamics. Results are presented for typical astrophysical scenarios. The differential cross section is strongly reduced at large energy transfer, where electrons dominate, and slightly reduced for small energy transfer, where nucleons dominate. At large densities, the nucleon effective mass is considerably lower than the free mass, and the region dominated by nucleons extends to larger energy transfer than for free nucleons. (orig.)

  18. Characteristics of X-ray fluorescence of nuclear materials

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seunghoon; Kwak, Sung-Woo; Shin, Jung-Ki; Park, Uk-Rayng; Jung, Heejun [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

    2015-10-15

    LED is a technique of determination of uranium concentration as a continuous X-ray energy beams transmit a uranium liquid sample for safeguards. Compared to K-edge densitometer, due to relatively lower energy (L-edge energy is 17.17 keV) of Uranium L series energy than K-series energy, L-edge densitometer does not require high purity germanium detector with liquid nitride cooling. Therefore, the Ledge densitometer is appropriate for portable equipment for on-site nuclear material inspection and safeguards at facility sites. XRF combined with LED is a technique of finding of nuclear materials from reflected characteristic X-ray photons. In this study, characteristics of XRF of nuclear materials are simulated Monte Carlo method (Geant4) for feasibility of the system for determination of concentration of nuclear species. The analysis method of uranium concentration or minor actinides is applied using combination of linear extrapolation from jump of L-edge of sample and ratio between uranium and minor actinide from XRF measurement. In this study, The XRF ch aracteristics was simulated from Monte Carlo method. The peaks were obtained from nuclear material mixture. The estimated nuclear material concentration is low due to the volume effect of the sample. The correction factor or minimization of the effect is required.

  19. {beta}-Ray angular distribution from purely nuclear spin aligned {sup 20}F

    Energy Technology Data Exchange (ETDEWEB)

    Nagatomo, T., E-mail: nagatomo@riken.jp [RIKEN Nishina Center (Japan); Matsuta, K. [Osaka University (Japan); Minamisono, K. [NSCL/MSU (United States); Sumikama, T. [Tokyo University of Science (Japan); Mihara, M. [Osaka University (Japan); Ozawa, A.; Tagishi, Y. [University of Tsukuba (Japan); Ogura, M.; Matsumiya, R.; Fukuda, M. [Osaka University (Japan); Yamaguchi, M.; Yasuno, T.; Ohta, H.; Hashizume, Y. [University of Tsukuba (Japan); Fujiwara, H. [Osaka University (Japan); Chiba, A. [University of Tsukuba (Japan); Minamisono, T. [Fukui University of Technology (Japan)

    2007-11-15

    The alignment correlation term in the {beta}-ray angular distribution from purely nuclear spin aligned {sup 20}F has been measured to test the G-parity conservation law which is one of the fundamental symmetries in the weak nucleon current. We utilized the hyperfine interaction of {sup 20}F in an MgF{sub 2} single crystal and successfully created the pure alignment from the polarization by means of the spin manipulation technique based on the {beta}-NMR method.

  20. Nuclear models and data for gamma-ray production

    International Nuclear Information System (INIS)

    Young, P.G.

    1975-01-01

    The current Evaluated Nuclear Data File (ENDF/B, Version IV) contains information on prompt gamma-ray production from neutron-induced reactions for some 38 nuclides. In addition, there is a mass of fission product yield, capture, and radioactive decay data from which certain time-dependent gamma-ray results can be calculated. These data are needed in such applications as gamma-ray heating calculations for reactors, estimates of radiation levels near nuclear facilities and weapons, shielding design calculations, and materials damage estimates. The prompt results are comprised of production cross sections, multiplicities, angular distributions, and energy spectra for secondary gamma-rays from a variety of reactions up to an incident neutron energy of 20 MeV. These data are based in many instances on experimental measurements, but nuclear model calculations, generally of a statistical nature, are also frequently used to smooth data, to interpolate between measurements, and to calculate data in unmeasured regions. The techniques and data used in determining the ENDF/B evaluations are reviewed, and comparisons of model-code calculations and ENDF data with recent experimental results are given. 11 figures

  1. Nuclear Physical Uncertainties in Modeling X-Ray Bursts

    Science.gov (United States)

    Regis, Eric; Amthor, A. Matthew

    2017-09-01

    Type I x-ray bursts occur when a neutron star accretes material from the surface of another star in a compact binary star system. For certain accretion rates and material compositions, much of the nuclear material is burned in short, explosive bursts. Using a one-dimensional stellar model, Kepler, and a comprehensive nuclear reaction rate library, ReacLib, we have simulated chains of type I x-ray bursts. Unfortunately, there are large remaining uncertainties in the nuclear reaction rates involved, since many of the isotopes reacting are unstable and have not yet been studied experimentally. Some individual reactions, when varied within their estimated uncertainty, alter the light curves dramatically. This limits our ability to understand the structure of the neutron star. Previous studies have looked at the effects of individual reaction rate uncertainties. We have applied a Monte Carlo method ``-simultaneously varying a set of reaction rates'' -in order to probe the expected uncertainty in x-ray burst behaviour due to the total uncertainty in all nuclear reaction rates. Furthermore, we aim to discover any nonlinear effects due to the coupling between different reaction rates. Early results show clear non-linear effects. This research was made possible by NSF-DUE Grant 1317446, BUScholars Program.

  2. Gamma-ray identification of nuclear weapon materials

    International Nuclear Information System (INIS)

    Gosnell, T. B.; Hall, J. M.; Jam, C. L.; Knapp, D. A.; Koenig, Z. M.; Luke, S. J.; Pohl, B. A.; Schach Wittenau, A. von; Wolford, J. K.

    1997-01-01

    There has been an accelerating national interest in countering nuclear smuggling. This has caused a corresponding expansion of interest in the use of gamma-ray spectrometers for checkpoint monitoring, nuclear search, and within networks of nuclear and collateral sensors. All of these are fieldable instruments--ranging from large, fixed portal monitors to hand-held and remote monitoring equipment. For operational reasons, detectors with widely varying energy resolution and detection efficiency will be employed. In many instances, such instruments must be sensitive to weak signals, always capable of recognizing the gamma-ray signatures from nuclear weapons materials (NWM), often largely insensitive to spectral alteration by radiation transport through intervening materials, capable of real-time implementation, and able to discriminate against signals from commonly encountered legitimate gamma-ray sources, such as radiopharmaceuticals. Several decades of experience in classified programs have shown that all of these properties are not easily achieved and successful approaches were of limited scope--such as the detection of plutonium only. This project was originally planned as a two-year LDRD-ER. Since funding for 1997 was not sustained, this is a report of the first year's progress

  3. The application of nuclear cross section measurements to spallation reactions in cosmic rays

    International Nuclear Information System (INIS)

    Raisbeck, G.M.; Yiou, F.

    1976-01-01

    The effects and implications of nuclear transformations of the comic ray particles themselves, and how those transformations are simulated in the laboratory are dealt with. Thus, although the majority of cosmic rays are protons and alpha particles, it is the small fraction of heavier species that is the main concern here. These nuclides interact with the interstellar matter (again mostly hydrogen and helium) in which they propagate, and thus can undergo nuclear reactions. For the cosmic ray physicist the effects of these reactions are both favourable and unfavourable. The unfavourable aspect arises from the fact that the composition of the cosmic ray is significantly altered, thus tending to mask an important indication as to their origin. Counterbalancing this is the fact that the effects left by the nuclear reactions are one of the most valuable links with the propagation process itself. A careful unravelling of these effects can thus reveal important information on where and how this propagation takes place. The type of nuclear information needed and techniques that are used to obtain it are considered. (Auth.)

  4. Investigation of nuclear interactions around 20 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Y [Waseda Univ., Tokyo (Japan). Science and Engineering Research Lab.; Sugimoto, H; Saito, T

    1976-12-01

    Nuclear interactions at a mean energy of about 20 TeV are studied by means of a nuclear emulsion chamber with jet producer. In the present analysis, particular emphasis is placed on the experimental condition. The transverse momentum spectrum of secondary ..gamma.. rays is approximated by a single exponential in a range of 0.3

    rays, E sub(..gamma..)/..sigma..E sub(..gamma..), in the range of 0.003

  5. High energy gamma-ray production in nuclear reactions

    International Nuclear Information System (INIS)

    Pinston, J.A.; Nifenecker, H.; Nifenecker, H.

    1989-01-01

    Experimental techniques used to study high energy gamma-ray production in nuclear reactions are reviewed. High energy photon production in nucleus-nucleus collisions is discussed. Semi-classical descriptions of the nucleus-nucleus gamma reactions are introduced. Nucleon-nucleon gamma cross sections are considered, including theoretical aspects and experimental data. High energy gamma ray production in proton-nucleus reactions is explained. Theoretical explanations of photon emission in nucleus-nucleus collisions are treated. The contribution of charged pion currents to photon production is mentioned

  6. Nuclear fusion induced by X-rays in a crystal

    OpenAIRE

    Belyaev, V. B.; Miller, M. B.; Otto, J.; Rakityansky, S. A.

    2016-01-01

    The nuclei that constitute a crystalline lattice, oscillate relative to each other with a very low energy that is not sufficient to penetrate through the Coulomb barriers separating them. An additional energy, which is needed to tunnel through the barrier and fuse, can be supplied by external electromagnetic waves (X-rays or the synchrotron radiation). Exposing to the X-rays the solid compound LiD (lithium-deuteride) for the duration of 111 hours, we have detected 88 events of the nuclear fus...

  7. The Nuclear Age: Context for Family Interaction.

    Science.gov (United States)

    Ptacek, Carmen

    1988-01-01

    Suggests that concerns regarding the nuclear threat are prevalent among family members; parents and children feel powerless in response to the nuclear threat; response to the nuclear threat is a family issue; responding to the nuclear threat requires empowering families and changing the social context; and nuclear concerns need to be addressed in…

  8. Simulation of intense laser-dense matter interactions. X-ray production and laser absorption

    Energy Technology Data Exchange (ETDEWEB)

    Ueshima, Yutaka; Kishimoto, Yasuaki; Sasaki, Akira [Japan Atomic Energy Research Inst., Neyagawa, Osaka (Japan). Kansai Research Establishment; Sentoku, Yasuhiko; Tajima, Toshiki

    1998-03-01

    The development of short-pulse ultra high intensity lasers will enable us to generate short-pulse intense soft and hard X-rays. Acceleration of an electron in laser field generates intense illuminated located radiation, Larmor radiation, around KeV at 10{sup 18} W/cm{sup 2} with 100 TW and 1 {mu}m wave length laser. The Coulomb interaction between rest ions and relativistic electron generates broad energy radiation, bremsstrahlung emission, over MeV at 10{sup 18} W/cm{sup 2} with the same condition. These intense radiations come in short pulses of the same order as that of the irradiated laser. The generated intense X-rays, Larmor and bremsstrahlung radiation, can be applied to sources of short pulse X-ray, excitation source of inner-shell X-ray laser, position production and nuclear excitation, etc. (author)

  9. Nuclear fusion induced by x rays in a crystal

    Science.gov (United States)

    Belyaev, V. B.; Miller, M. B.; Otto, J.; Rakityansky, S. A.

    2016-03-01

    The nuclei that constitute a crystalline lattice oscillate relative to each other with a very low energy that is not sufficient to penetrate through the Coulomb barriers separating them. An additional energy, which is needed to tunnel through the barrier and fuse, can be supplied by external electromagnetic waves (x rays or synchrotron radiation). Exposing the solid compound LiD (lithium deuteride) to x rays for the duration of 111 h, we detect 88 events of nuclear fusion d +6Li→8Be* . Our theoretical estimate agrees with what we observed. One possible application of the phenomenon we found is in measurements of the rates of various nuclear reactions (not necessarily fusion) at extremely low energies inaccessible in accelerator experiments.

  10. Cosmic ray muons for spent nuclear fuel monitoring

    Science.gov (United States)

    Chatzidakis, Stylianos

    There is a steady increase in the volume of spent nuclear fuel stored on-site (at reactor) as currently there is no permanent disposal option. No alternative disposal path is available and storage of spent nuclear fuel in dry storage containers is anticipated for the near future. In this dissertation, a capability to monitor spent nuclear fuel stored within dry casks using cosmic ray muons is developed. The motivation stems from the need to investigate whether the stored content agrees with facility declarations to allow proliferation detection and international treaty verification. Cosmic ray muons are charged particles generated naturally in the atmosphere from high energy cosmic rays. Using muons for proliferation detection and international treaty verification of spent nuclear fuel is a novel approach to nuclear security that presents significant advantages. Among others, muons have the ability to penetrate high density materials, are freely available, no radiological sources are required and consequently there is a total absence of any artificial radiological dose. A methodology is developed to demonstrate the applicability of muons for nuclear nonproliferation monitoring of spent nuclear fuel dry casks. Purpose is to use muons to differentiate between spent nuclear fuel dry casks with different amount of loading, not feasible with any other technique. Muon scattering and transmission are used to perform monitoring and imaging of the stored contents of dry casks loaded with spent nuclear fuel. It is shown that one missing fuel assembly can be distinguished from a fully loaded cask with a small overlapping between the scattering distributions with 300,000 muons or more. A Bayesian monitoring algorithm was derived to allow differentiation of a fully loaded dry cask from one with a fuel assembly missing in the order of minutes and negligible error rate. Muon scattering and transmission simulations are used to reconstruct the stored contents of sealed dry casks

  11. Nuclear spectroscopy with density dependent effective interactions

    International Nuclear Information System (INIS)

    Krewald, S.

    1976-07-01

    The paper investigates excited nuclear states with density-dependent effective interactions. In the first part of the paper, the structure and the width of the multipole giant resonances discovered in 1972 are derived microscopically. Because of their high excitation energy, these giant resonances are unstable to particle emission and thus often have a considerable decay width. Due to their collective structure, the giant resonances can be described by RPA in good approximation. In this paper, the continuum RPA is applied to the spherical nuclei 16 O, 40 Ca, 90 Zr and 208 Pb. The experimental centroid energy are in very good agreement with the calculations performed in the paper. (orig./WL) [de

  12. Description of superdeformed nuclear states in the interacting boson model

    International Nuclear Information System (INIS)

    Liu, Y.; Zhao, E.; Liu, Y.; Song, J.; Liu, Y.; Sun, H.; Zhao, E.; Liu, Y.; Sun, H.

    1997-01-01

    We show in this paper that the superdeformed nuclear states can be described with a four parameter formula in the spirit of the perturbated SU(3) limit of the sdg IBM. The E2 transition γ-ray energies, the dynamical moments of inertia of the lowest superdeformed (SD) bands in even-even Hg, Pb, Gd, and Dy isotopes, and the energy differences ΔE γ -ΔE γ ref of the SD band 1 of 194 Hg are calculated. The calculated results agree with experimental data well. This indicates that the SD states are governed by a rotational interaction plus a perturbation with SO sdg (5) symmetry. The perturbation causing the ΔI=4 bifurcation to emerge in the ΔI=2 superdeformed rotational band may then possess SO sdg (5) symmetry. copyright 1997 The American Physical Society

  13. A library for X-ray-matter interaction cross sections for X-ray fluorescence applications

    Energy Technology Data Exchange (ETDEWEB)

    Brunetti, A. [Istituto di Matematica e Fisica, Universita di Sassari, via Vienna 2, 07100 Sassari (Italy) and INFN, Sezione di Cagliari (Italy)]. E-mail: brunetti@uniss.it; Sanchez del Rio, M. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble Cedex (France); Golosio, B. [INFN, Sezione di Cagliari (Italy); European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble Cedex (France); Simionovici, A. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble Cedex (France); Laboratoire de Sciences de la Terre, Ecole Normale Superieure, Lyon, F-69364 (France); Somogyi, A. [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, 38043 Grenoble Cedex (France)

    2004-10-08

    Quantitative estimate of elemental composition by spectroscopic and imaging techniques using X-ray fluorescence requires the availability of accurate data of X-ray interaction with matter. Although a wide number of computer codes and data sets are reported in literature, none of them is presented in the form of freely available library functions which can be easily included in software applications for X-ray fluorescence. This work presents a compilation of data sets from different published works and an xraylib interface in the form of callable functions. Although the target applications are on X-ray fluorescence, cross sections of interactions like photoionization, coherent scattering and Compton scattering, as well as form factors and anomalous scattering functions, are also available.

  14. Three nucleon interaction and nuclear composition

    International Nuclear Information System (INIS)

    Pandharipande, V.R.

    1983-01-01

    The author discusses results of some of the calculations carried out by J. Carlson, I. Lagaris, J. Lomnitz-Adler, R.A. Smith, R.B. Wiringa and himself to study the three nucleon interaction. The group has attempted to calculate the wavefunctions and binding energies of 3 H, 3 He, 4 He and nuclear matter, with the variational method, from a nonrelativistic Hamiltonian. Only nucleon degrees of freedom are retained in this Hamiltonian; the effects of other degrees of freedom are implicit in the two and three nucleon potentials. The author discusses further the calculations carried out, in collaboration with B. Friman, and R.B. Wiringa, to study the composition of nuclei. Nucleons interact by many processes including exchange of pions with or without excitation to isobar (Δ) states. Thus the nucleus contains pions being exchanged, and some nucleons in the Δ state. The group attempts to calculate the number and momentum distribution of these exchanged pions, and the fraction of time a nucleon in the nucleus is in the Δ state. 21 references, 4 figures

  15. Neutron Capture Gamma-Ray Libraries for Nuclear Applications

    International Nuclear Information System (INIS)

    Sleaford, B. W.; Summers, N.; Escher, J.; Firestone, R. B.; Basunia, S.; Hurst, A.; Krticka, M.; Molnar, G.; Belgya, T.; Revay, Z.; Choi, H. D.

    2011-01-01

    The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. This can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research Project. EGAF is being used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90% of all the decay energy and is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. We are investigating the capture spectra from higher energy neutrons experimentally using surrogate reactions and modeling this with Hauser-Feshbach codes. This can then be used to benchmark CASINO, a version of DICEBOX modified for neutron capture at higher energy. This can be used to simulate spectra from neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modeling of unknown assemblies.

  16. Neutron Capture Gamma-Ray Libraries for Nuclear Applications

    International Nuclear Information System (INIS)

    Sleaford, B.W.; Firestone, R.B.; Summers, N.; Escher, J.; Hurst, A.; Krticka, M.; Basunia, S.; Molnar, G.; Belgya, T.; Revay, Z.; Choi, H.D.

    2010-01-01

    The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. this can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research project. EGAF is being used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90% of all the decay energy and is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. They are investigating the capture spectra from higher energy neutrons experimentally using surrogate reactions and modeling this with Hauser-Feshbach codes. This can then be used to benchmark CASINO, a version of DICEBOX modified for neutron capture at higher energy. This can be used to simulate spectra from neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modeling of unknown assemblies.

  17. Capture Gamma-Ray Libraries for Nuclear Applications

    International Nuclear Information System (INIS)

    Sleaford, B.W.; Firestone, Richard B.; Summers, N.; Escher, J.; Hurst, A.; Krticka, M.; Basunia, S.; Molnar, G.; Belgya, T.; Revay, Z.; Choi, H.D.

    2010-01-01

    The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. This can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research Project. EGAF has been used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90% of all the decay energy an is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. We use CASINO, a version of DICEBOX that is modified for this purpose. This can be used to simulate the neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modelling of unknown assemblies.

  18. On evaluated nuclear data for beta-delayed gamma rays following of special nuclear materials

    Energy Technology Data Exchange (ETDEWEB)

    Mencarini, Leonardo de H.; Caldeira, Alexandre D., E-mail: mencarini@ieav.cta.b, E-mail: alexdc@ieav.cta.b [Instituto de Estudos Avancados (IEAv/CTA), Sao Jose dos Campos, SP (Brazil)

    2011-07-01

    In this paper, a new type of information available in ENDF is discussed. During a consistency check of the evaluated nuclear data library ENDF/B-VII.0 performed at the Nuclear Data Subdivision of the Institute for Advanced Studies, the size of the files for some materials drew the attention of one of the authors. Almost 94 % of all available information for these special nuclear materials is used to represent the beta-delayed gamma rays following fission. This is the first time this information is included in an ENDF version. (author)

  19. On evaluated nuclear data for beta-delayed gamma rays following of special nuclear materials

    International Nuclear Information System (INIS)

    Mencarini, Leonardo de H.; Caldeira, Alexandre D.

    2011-01-01

    In this paper, a new type of information available in ENDF is discussed. During a consistency check of the evaluated nuclear data library ENDF/B-VII.0 performed at the Nuclear Data Subdivision of the Institute for Advanced Studies, the size of the files for some materials drew the attention of one of the authors. Almost 94 % of all available information for these special nuclear materials is used to represent the beta-delayed gamma rays following fission. This is the first time this information is included in an ENDF version. (author)

  20. Nuclear physics meets the sources of the ultra-high energy cosmic rays

    International Nuclear Information System (INIS)

    Boncioli, Denise; Fedynitch, Anatoli; Winter, Walter

    2016-07-01

    We study the implications of nuclear data and models for cosmic-ray astrophysics, which involves the photodisintegration of nuclei up to iron in astrophysical environments. We demonstrate that data on photo-absorption cross sections are sparse in that mass range by screening nuclear databases, such as EXFOR; these cross sections are needed to compute the photodisintegration rates. We also test the prediction power of models, such as TALYS, and find uncertainties of the order of a factor two. If however the radiation fields are strong enough such that the nuclear cascade in the astrophysical source can develop, we find that differences among different models average out -- unless there is a systematic offset in the interaction model. We conclude with an isotope chart describing which information is in principle necessary to describe nuclear interactions, supported by simulating the entire disintegration chain in a gamma-ray burst. We also point out that a first consistency check may be the measurement of the absorption cross section for different isobars.

  1. Nuclear physics meets the sources of the ultra-high energy cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Boncioli, Denise; Fedynitch, Anatoli; Winter, Walter

    2016-07-15

    We study the implications of nuclear data and models for cosmic-ray astrophysics, which involves the photodisintegration of nuclei up to iron in astrophysical environments. We demonstrate that data on photo-absorption cross sections are sparse in that mass range by screening nuclear databases, such as EXFOR; these cross sections are needed to compute the photodisintegration rates. We also test the prediction power of models, such as TALYS, and find uncertainties of the order of a factor two. If however the radiation fields are strong enough such that the nuclear cascade in the astrophysical source can develop, we find that differences among different models average out -- unless there is a systematic offset in the interaction model. We conclude with an isotope chart describing which information is in principle necessary to describe nuclear interactions, supported by simulating the entire disintegration chain in a gamma-ray burst. We also point out that a first consistency check may be the measurement of the absorption cross section for different isobars.

  2. Development of cosmic-ray radiography with nuclear emulsion and its applications

    International Nuclear Information System (INIS)

    Morishima, Kunihiro

    2017-01-01

    We are developing cosmic-ray radiography with nuclear emulsion. Cosmic-ray radiography is non-destructive inspection technology to take image of inner structure of gigantic objects (nuclear reactor, pyramids, volcanoes and so on). We conducted cosmic-ray radiography of Fukushima Daiichi Nuclear Power Plant from 2014 to 2015 and are conducting cosmic-ray radiography of Pyramids at Egypt from 2015. In this paper, technical details and latest results are presented. (author)

  3. Gamma-ray and X-ray emission from the Galactic centre: hints on the nuclear star cluster formation history

    Science.gov (United States)

    Arca-Sedda, Manuel; Kocsis, Bence; Brandt, Timothy D.

    2018-06-01

    The Milky Way centre exhibits an intense flux in the gamma and X-ray bands, whose origin is partly ascribed to the possible presence of a large population of millisecond pulsars (MSPs) and cataclysmic variables (CVs), respectively. However, the number of sources required to generate such an excess is much larger than what is expected from in situ star formation and evolution, opening a series of questions about the formation history of the Galactic nucleus. In this paper we make use of direct N-body simulations to investigate whether these sources could have been brought to the Galactic centre by a population of star clusters that underwent orbital decay and formed the Galactic nuclear star cluster (NSC). Our results suggest that the gamma ray emission is compatible with a population of MSPs that were mass segregated in their parent clusters, while the X-ray emission is consistent with a population of CVs born via dynamical interactions in dense star clusters. Combining observations with our modelling, we explore how the observed γ ray flux can be related to different NSC formation scenarios. Finally, we show that the high-energy emission coming from the galactic central regions can be used to detect black holes heavier than 105M⊙ in nearby dwarf galaxies.

  4. Gamma-ray imaging. Applications in nuclear non-proliferation and homeland security

    International Nuclear Information System (INIS)

    Vetter, Kai; Mihailescu, Lucian

    2010-01-01

    This paper provides the motivation and describes implementations of gamma-ray imaging for homeland security applications and more general for national and international nuclear security. As in nuclear medicine and astrophysics, the goal of gamma-ray imaging is the detection and localization of nuclear materials, however, here in a terrestrial environment with distances between nuclear medicine and astrophysics, i.e. in the range of 1-100 meters. Due to the recently increased threat of nuclear terrorism, the detection of illicit nuclear materials and the prevention of nuclear proliferation through the development of advanced gamma-ray imaging concepts and technologies has become and active research field. (author)

  5. Constraining strong baryon-dark-matter interactions with primordial nucleosynthesis and cosmic rays

    International Nuclear Information System (INIS)

    Cyburt, Richard H.; Fields, Brian D.; Pavlidou, Vasiliki; Wandelt, Benjamin

    2002-01-01

    Self-interacting dark matter (SIDM) was introduced by Spergel and Steinhardt to address possible discrepancies between collisionless dark matter simulations and observations on scales of less than 1 Mpc. We examine the case in which dark matter particles not only have strong self-interactions but also have strong interactions with baryons. The presence of such interactions will have direct implications for nuclear and particle astrophysics. Among these are a change in the predicted abundances from big bang nucleosynthesis (BBN) and the flux of γ rays produced by the decay of neutral pions which originate in collisions between dark matter and galactic cosmic rays (CR). From these effects we constrain the strength of the baryon-dark-matter interactions through the ratio of baryon-dark-matter interaction cross section to dark matter mass, s. We find that BBN places a weak upper limit on this ratio (less-or-similar sign)10 8 cm 2 g -1 . CR-SIDM interactions, however, limit the possible DM-baryon cross section to (less-or-similar sign)5x10 -3 cm 2 g -1 ; this rules out an energy-independent interaction, but not one which falls with center-of-mass velocity s∝1/v or steeper

  6. Integrated neutron/gamma-ray portal monitors for nuclear safeguards

    International Nuclear Information System (INIS)

    Fehlau, P.E.

    1994-01-01

    Radiation monitoring is one nuclear-safeguards measure used to protect against the theft of special nuclear materials (SNM) by pedestrians departing from SNM access areas. The integrated neutron/gamma-ray portal monitor is an ideal radiation monitor for the task when the SNM is plutonium. It achieves high sensitivity for detecting both bare and shielded plutonium by combining two types of radiation detector. One type is a neutron-chamber detector, comprising a large, hollow, neutron moderator that contains a single thermal-neutron proportional counter. The entrance wall of each chamber is thin to admit slow neutrons from plutonium contained in a moderating shield, while the other walls are thick to moderate fast neutrons from bare or lead-shielded plutonium so that they can be detected. The other type of detector is a plastic scintillator that is primarily for detecting gamma rays from small amounts of unshielded plutonium. The two types of detector are easily integrated by making scintillators part of the thick back wall of each neutron chamber or by inserting them into each chamber void. The authors compared the influence of the two methods of integration on detecting neutrons and gamma rays, and they examined the effectiveness of other design factors and the methods for signal detection as well

  7. Nuclear science and metallurgy. Advances and interactions

    International Nuclear Information System (INIS)

    Grison, Emmanuel

    1977-01-01

    The history of the production of atomic power by fission since 1953 is reviewed: metallurgy of uranium; the new metals zirconium and beryllium; steels and nuclear structure; nuclear reactor vessels; water corrosion; effects of radiations [fr

  8. Nuclear science and metallurgy. Advances and interactions

    Energy Technology Data Exchange (ETDEWEB)

    Grison, E [CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1977-01-01

    The history of the production of atomic power by fission since 1953 is reviewed: metallurgy of uranium; the new metals zirconium and beryllium; steels and nuclear structure; nuclear reactor vessels; water corrosion; effects of radiations.

  9. Polarization phenomena of nuclear force and weak interaction

    International Nuclear Information System (INIS)

    Konuma, Michitsugu

    1982-01-01

    As one of the projects at the National Laboratory of High Energy Physics (KEK), the measurement of parity non-conservation component in nuclear force was proposed. The theoretical survey of this proposal is reported. The non-relativistic parity non-conserving potential between nucleons can be obtained from the interaction between a quark and a gauge boson. The wave function of a nucleus, which includes the inverse components of the parity, can be written. A practical experiment was designed. The mixing of the inverse components and the interference of an inverse component in the 1042 keV and 1081 keV levels of F 18 may produce the parity non-conservation. The processes which suggest the existence of parity non-conservation were studied. The processes are the circular polarization of gamma-ray emitted from a nucleus, the angular distribution of gamma-ray emitted from polarized nuclei, the collision of the proton beam with helicity of plus and minus on other nuclei, the spin rotation of neutrons, and the alpha decay of the parity non-conservation. The preliminary results of the experiment on the effects of parity non-conservation in the collision process of polarized proton beam have been reported, and the theoretical analyses were performed. The violation of parity conservation in large momentum collision is discussed. The comparison of the theoretical results with the experimental ones is presented. (Kato, T.)

  10. Gamma-ray tracking - A new detector concept for nuclear spectroscopy

    International Nuclear Information System (INIS)

    Gast, W.

    2001-01-01

    In the framework of an European collaboration the nest generation of large efficiency, high resolution spectrometers for nuclear spectroscopy is under development. The new spectrometers are large volume, segmented Ge-detectors featuring 3D position sensitivity in order to allow Gamma-Ray Tracking. That is, knowing the interaction positions and the energies released at each interaction, the track each gamma-ray follows during its scattering process inside the detector volume can be reconstructed on basis of the Compton-scattering formula. The resulting high add-back efficiency an effective granularity significantly improves peak-to-total ratio, efficiency, and Doppler-broadening of the spectrometer. In this contribution the states of the project concerning detector design and development of digital signal processing techniques to achieve an optimal 3D position sensitivity is presented. (authors)

  11. Stabilization of the Electron-Nuclear Spin Orientation in Quantum Dots by the Nuclear Quadrupole Interaction

    Science.gov (United States)

    Dzhioev, R. I.; Korenev, V. L.

    2007-07-01

    The nuclear quadrupole interaction eliminates the restrictions imposed by hyperfine interaction on the spin coherence of an electron and nuclei in a quantum dot. The strain-induced nuclear quadrupole interaction suppresses the nuclear spin flip and makes possible the zero-field dynamic nuclear polarization in self-organized InP/InGaP quantum dots. The direction of the effective nuclear magnetic field is fixed in space, thus quenching the magnetic depolarization of the electron spin in the quantum dot. The quadrupole interaction suppresses the zero-field electron spin decoherence also for the case of nonpolarized nuclei. These results provide a new vision of the role of the nuclear quadrupole interaction in nanostructures: it elongates the spin memory of the electron-nuclear system.

  12. Special Nuclear Material Gamma-Ray Signatures for Reachback Analysts

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Myers, Steven Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-29

    These are slides on special nuclear material gamma-ray signatures for reachback analysts for an LSS Spectroscopy course. The closing thoughts for this presentation are the following: SNM materials have definite spectral signatures that should be readily recognizable to analysts in both bare and shielded configurations. One can estimate burnup of plutonium using certain pairs of peaks that are a few keV apart. In most cases, one cannot reliably estimate uranium enrichment in an analogous way to the estimation of plutonium burnup. The origin of the most intense peaks from some SNM items may be indirect and from ‘associated nuclides.' Indirect SNM signatures sometimes have commonalities with the natural gamma-ray background.

  13. X-ray holography: X-ray interactions and their effects

    International Nuclear Information System (INIS)

    London, R.A.; Trebes, J.E.; Rosen, M.D.

    1988-01-01

    The authors summarize a theoretical study of the interactions of x-rays with a biological sample during the creation of a hologram. The choice of an optimal wavelength for x-ray holography is discussed, based on a description of scattering by objects within an aqueous environment. The problem of the motion resulting from the absorption of x-rays during a short exposure is described. The possibility of using very short exposures in order to capture the image before motion can compromise the resolution is explored. The impact of these calculation on the question of the feasibility of using an x-ray laser for holography of biological structures is discussed. 12 refs., 2 figs

  14. Characterising encapsulated nuclear waste using cosmic-ray muon tomography

    International Nuclear Information System (INIS)

    Clarkson, A.; Hamilton, D.J.; Hoek, M.; Ireland, D.G.; Kaiser, R.; Keri, T.; Lumsden, S.; Mahon, D.F.; McKinnon, B.; Murray, M.; Nutbeam-Tuffs, S.; Yang, G.; Johnstone, J.R.; Shearer, C.; Zimmerman, C.

    2015-01-01

    Tomographic imaging techniques using the Coulomb scattering of cosmic-ray muons have been shown previously to successfully identify and characterise low- and high-Z materials within an air matrix using a prototype scintillating-fibre tracker system. Those studies were performed as the first in a series to assess the feasibility of this technology and image reconstruction techniques in characterising the potential high-Z contents of legacy nuclear waste containers for the U.K. Nuclear Industry. The present work continues the feasibility study and presents the first images reconstructed from experimental data collected using this small-scale prototype system of low- and high-Z materials encapsulated within a concrete-filled stainless-steel container. Clear discrimination is observed between the thick steel casing, the concrete matrix and the sample materials assayed. These reconstructed objects are presented and discussed in detail alongside the implications for future industrial scenarios

  15. Characterising encapsulated nuclear waste using cosmic-ray muon tomography

    Science.gov (United States)

    Clarkson, A.; Hamilton, D. J.; Hoek, M.; Ireland, D. G.; Johnstone, J. R.; Kaiser, R.; Keri, T.; Lumsden, S.; Mahon, D. F.; McKinnon, B.; Murray, M.; Nutbeam-Tuffs, S.; Shearer, C.; Yang, G.; Zimmerman, C.

    2015-03-01

    Tomographic imaging techniques using the Coulomb scattering of cosmic-ray muons have been shown previously to successfully identify and characterise low- and high-Z materials within an air matrix using a prototype scintillating-fibre tracker system. Those studies were performed as the first in a series to assess the feasibility of this technology and image reconstruction techniques in characterising the potential high-Z contents of legacy nuclear waste containers for the U.K. Nuclear Industry. The present work continues the feasibility study and presents the first images reconstructed from experimental data collected using this small-scale prototype system of low- and high-Z materials encapsulated within a concrete-filled stainless-steel container. Clear discrimination is observed between the thick steel casing, the concrete matrix and the sample materials assayed. These reconstructed objects are presented and discussed in detail alongside the implications for future industrial scenarios.

  16. Cosmic-ray interactions and dating of meteorite stranding surfaces with cosmogenic nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Reedy, R.C.

    1988-01-01

    A wide variety of products from cosmic-ray interactions have been measured in terrestrial or extraterrestrial samples. These ''cosmogenic'' products include radiation damage tracks and rare nuclides that are made by nuclear reactions. They often have been used to determine the fluxes and composition of cosmic-ray particles in the past, but they are usually used to study the history of the ''target'' (such as the time period that it was exposed to cosmic-ray particles). Products made by both the high-energy galactic cosmic rays and energetic particles emitted irregularly from the Sun have been extensively studied. Some of these cosmogenic products, especially nuclides, have been or can be applied to studies of Antarctic meteorite stranding surfaces, the ice surfaces in Antarctica where meteorites have been found. Cosmogenic nuclides studied in samples from Antarctica and reported by others elsewhere in this volume include those in meteorites, especially radionuclides used to determine terrestrial ages, and those made in situ in terrestrial rocks. Cosmogenic nuclides made in the Earth's atmosphere or brought in with cosmic dust have also been studied in polar ice, and it should also be possible to measure nuclides made in situ in ice. As an introduction to cosmogenic nuclides and their applications, cosmic rays and their interactions will be presented below and production systematics of cosmogenic nuclides in these various media will be discussed later. 20 refs., 2 tabs.

  17. Cosmic-ray interactions and dating of meteorite stranding surfaces with cosmogenic nuclides

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1988-01-01

    A wide variety of products from cosmic-ray interactions have been measured in terrestrial or extraterrestrial samples. These ''cosmogenic'' products include radiation damage tracks and rare nuclides that are made by nuclear reactions. They often have been used to determine the fluxes and composition of cosmic-ray particles in the past, but they are usually used to study the history of the ''target'' (such as the time period that it was exposed to cosmic-ray particles). Products made by both the high-energy galactic cosmic rays and energetic particles emitted irregularly from the Sun have been extensively studied. Some of these cosmogenic products, especially nuclides, have been or can be applied to studies of Antarctic meteorite stranding surfaces, the ice surfaces in Antarctica where meteorites have been found. Cosmogenic nuclides studied in samples from Antarctica and reported by others elsewhere in this volume include those in meteorites, especially radionuclides used to determine terrestrial ages, and those made in situ in terrestrial rocks. Cosmogenic nuclides made in the Earth's atmosphere or brought in with cosmic dust have also been studied in polar ice, and it should also be possible to measure nuclides made in situ in ice. As an introduction to cosmogenic nuclides and their applications, cosmic rays and their interactions will be presented below and production systematics of cosmogenic nuclides in these various media will be discussed later. 20 refs., 2 tabs

  18. Neutron interrogation system using high gamma ray signature to detect contraband special nuclear materials in cargo

    Science.gov (United States)

    Slaughter, Dennis R [Oakland, CA; Pohl, Bertram A [Berkeley, CA; Dougan, Arden D [San Ramon, CA; Bernstein, Adam [Palo Alto, CA; Prussin, Stanley G [Kensington, CA; Norman, Eric B [Oakland, CA

    2008-04-15

    A system for inspecting cargo for the presence of special nuclear material. The cargo is irradiated with neutrons. The neutrons produce fission products in the special nuclear material which generate gamma rays. The gamma rays are detecting indicating the presence of the special nuclear material.

  19. Cosmic-ray and neutrino emission from Gamma-Ray Bursts with a nuclear cascade

    Energy Technology Data Exchange (ETDEWEB)

    Biehl, Daniel; Boncioli, Denise; Fedynitch, Anatoli; Winter, Walter

    2017-05-24

    We discuss neutrino and cosmic-ray emission from Gamma-Ray Bursts (GRBs) with the injection of nuclei, where we take into account that a nuclear cascade from photo-disintegration can fully develop in the source. One of our main objectives is to test if recent results from the IceCube and the Pierre Auger Observatory can be accommodated with the paradigm that GRBs are the sources of Ultra-High Energy Cosmic Rays (UHECRs). While our key results are obtained using an internal shock model, we discuss how the secondary emission from a GRB shell can be interpreted in terms of other astrophysical models. It is demonstrated that the expected neutrino flux from GRBs weakly depends on the injection composition, which implies that prompt neutrinos from GRBs can efficiently test the GRB-UHECR paradigm even if the UHECRs are nuclei. We show that the UHECR spectrum and composition, as measured by the Pierre Auger Observatory, can be self-consistently reproduced in a combined source-propagation model. In an attempt to describe the energy range including the ankle, we find tension with the IceCube bounds from the GRB stacking analyses. In an alternative scenario, where only the UHECRs beyond the ankle originate from GRBs, the requirement for a joint description of cosmic-ray and neutrino observations favors lower luminosities, which does not correspond to the typical expectation from γ-ray observations.

  20. Cosmic-ray and neutrino emission from Gamma-Ray Bursts with a nuclear cascade

    International Nuclear Information System (INIS)

    Biehl, Daniel; Boncioli, Denise; Fedynitch, Anatoli; Winter, Walter

    2017-01-01

    We discuss neutrino and cosmic-ray emission from Gamma-Ray Bursts (GRBs) with the injection of nuclei, where we take into account that a nuclear cascade from photo-disintegration can fully develop in the source. One of our main objectives is to test if recent results from the IceCube and the Pierre Auger Observatory can be accommodated with the paradigm that GRBs are the sources of Ultra-High Energy Cosmic Rays (UHECRs). While our key results are obtained using an internal shock model, we discuss how the secondary emission from a GRB shell can be interpreted in terms of other astrophysical models. It is demonstrated that the expected neutrino flux from GRBs weakly depends on the injection composition, which implies that prompt neutrinos from GRBs can efficiently test the GRB-UHECR paradigm even if the UHECRs are nuclei. We show that the UHECR spectrum and composition, as measured by the Pierre Auger Observatory, can be self-consistently reproduced in a combined source-propagation model. In an attempt to describe the energy range including the ankle, we find tension with the IceCube bounds from the GRB stacking analyses. In an alternative scenario, where only the UHECRs beyond the ankle originate from GRBs, the requirement for a joint description of cosmic-ray and neutrino observations favors lower luminosities, which does not correspond to the typical expectation from γ-ray observations.

  1. Cosmic ray and neutrino emission from gamma-ray bursts with a nuclear cascade

    Science.gov (United States)

    Biehl, D.; Boncioli, D.; Fedynitch, A.; Winter, W.

    2018-04-01

    Aim. We discuss neutrino and cosmic ray emission from gamma-ray bursts (GRBs) with the injection of nuclei, where we take into account that a nuclear cascade from photodisintegration can fully develop in the source. Our main objective is to test whether recent results from the IceCube and the Pierre Auger Observatory can be accommodated within the paradigm that GRBs are the sources of ultra-high-energy cosmic rays (UHECRs). Methods: We simulate this scenario in a combined source-propagation model. While our key results are obtained using an internal shock model of the source, we discuss how the secondary emission from a GRB shell can be interpreted in terms of other astrophysical models. Results: We demonstrate that the expected neutrino flux from GRBs weakly depends on the injection composition for the same injection spectra and luminosities, which implies that prompt neutrinos from GRBs can efficiently test the GRB-UHECR paradigm even if the UHECRs are nuclei. We show that the UHECR spectrum and composition, as measured by the Pierre Auger Observatory, can be self-consistently reproduced. In an attempt to describe the energy range including the ankle, we find tension with the IceCube bounds from the GRB stacking analyses. In an alternative scenario, where only the UHECRs beyond the ankle originate from GRBs, the requirement for a joint description of cosmic ray and neutrino observations favors lower luminosities, which does not correspond to the typical expectation from γ-ray observations.

  2. Muon Production in Relativistic Cosmic-Ray Interactions

    International Nuclear Information System (INIS)

    Klein, Spencer

    2009-01-01

    Cosmic-rays with energies up to 3 x 10 20 eV have been observed. The nuclear composition of these cosmic rays is unknown but if the incident nuclei are protons then the corresponding center of mass energy is √s nn = 700 TeV. High energy muons can be used to probe the composition of these incident nuclei. The energy spectra of high-energy (> 1 TeV) cosmic ray induced muons have been measured with deep underground or under-ice detectors. These muons come from pion and kaon decays and from charm production in the atmosphere. Terrestrial experiments are most sensitive to far-forward muons so the production rates aresensitive to high-x partons in the incident nucleus and low-x partons in the nitrogen/oxygen targets. Muon measurements can complement the central-particle data collected at colliders. This paper will review muon production data and discuss some non-perturbative (soft) models that have been used to interpret the data. I will show measurements of TeV muon transverse momentum (p T ) spectra in cosmic-ray air showers from MACRO, and describe how the IceCube neutrino observatory and the proposed Km3Net detector will extend these measurements to a higher p T region where perturbative QCD should apply. With a 1 km 2 surface area, the full IceCube detector should observe hundreds of muons/year with p T in the pQCD regime.

  3. Hard X-ray mirrors for Nuclear Security

    Energy Technology Data Exchange (ETDEWEB)

    Descalle, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brejnholt, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hill, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Decker, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Alameda, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Soufli, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pivovaroff, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pardini, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-01-07

    Research performed under this LDRD aimed to demonstrate the ability to detect and measure hard X-ray emissions using multilayer X-ray reflective optics above 400 keV, to enable the development of inexpensive and high-accuracy mirror substrates, and to investigate applications of hard X-ray mirrors of interest to the nuclear security community. Experiments conducted at the European Synchrotron Radiation Facility demonstrated hard X-ray mirror reflectivity up to 650 keV for the first time. Hard X-ray optics substrates must have surface roughness under 3 to 4 Angstrom rms, and three materials were evaluated as potential substrates: polycarbonates, thin Schott glass and a new type of flexible glass called Willow Glass®. Chemical smoothing and thermal heating of the surface of polycarbonate samples, which are inexpensive but have poor intrinsic surface characteristics, did not yield acceptable surface roughness. D263 Schott glass was used for the focusing optics of the NASA NuSTAR telescope. The required specialized hardware and process were costly and motivated experiments with a modified non-contact slumping technique. The surface roughness of the glass was preserved and the process yielded cylindrical shells with good net shape pointing to the potential advantage of this technique. Finally, measured surface roughness of 200 and 130 μm thick Willow Glass sheets was between 2 and 2.5 A rms. Additional results of flexibility tests and multilayer deposition campaigns indicated it is a promising substrate for hard X-ray optics. The detection of U and Pu characteristics X-ray lines and gamma emission lines in a high background environment was identified as an area for which X-ray mirrors could have an impact and where focusing optics could help reduce signal to noise ratio by focusing signal onto a smaller detector. Hence the first one twelvetant of a Wolter I focusing optics for the 90 to 140 keV energy range based on aperiodic multilayer coating was designed. Finally

  4. X-ray lines and self-interacting dark matter.

    Science.gov (United States)

    Mambrini, Yann; Toma, Takashi

    We study the correlation between a monochromatic signal from annihilating dark matter and its self-interacting cross section. We apply our argument to a complex scalar dark sector, where the pseudo-scalar plays the role of a warm dark matter candidate while the scalar mediates its interaction with the Standard Model. We combine the recent observation of the cluster Abell 3827 for self-interacting dark matter and the constraints on the annihilation cross section for monochromatic X-ray lines. We also confront our model to a set of recent experimental analyses and find that such an extension can naturally produce a monochromatic keV signal corresponding to recent observations of Perseus or Andromeda, while in the meantime it predicts a self-interacting cross section of the order of [Formula: see text], as recently claimed in the observation of the cluster Abell 3827. We also propose a way to distinguish such models by future direct detection techniques.

  5. Gamma-Ray interaction probabilities for some liquid scintillators

    International Nuclear Information System (INIS)

    Garcia-Torano Martinez, E.; Grau Malonda, A.

    1989-01-01

    Interaction probabilities for 17 gamma-Ray energies between 1 and 1.000 KeV have been computed and tabulated. The tables may be applied to the case of cylindrical vials with radius 1,25 cm and volumes 5, 10 and 15 ml. Toluene, Toluene/Alcohol, Dioxane-Naftalene, PCS, INSTAGEL and HISAFE II scintillators are considered. Graphical results for 10 ml are also given. (Author)

  6. Electron spin-lattice relaxation mechanisms of radiation produced trapped electrons and hydrogen atoms in aqueous and organic glassy matrices. Modulation of electron nuclear dipolar interaction by tunnelling modes in a glassy matrix. [. gamma. rays

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, M K; Kevan, L [Wayne State Univ., Detroit, Mich. (USA). Dept. of Chemistry

    1977-01-01

    The spin lattice relaxation of trapped electrons in aqueous and organic glasses and trapped hydrogen atoms in phosphoric acid glass has been directly studied as a function of temperature by the saturation recovery method. Below 50 to 100 K, the major spin lattice relaxation mechanism involves modulation of the electron nuclear dipolar (END) interaction with nuclei in the radical's environment by tunnelling of those nuclei between two or more positions. This relaxation mechanism occurs with high efficiency and has a characteristic linear temperature dependence. The tunnelling nuclei around trapped electrons do not seem to involve the nearest neighbor nuclei which are oriented by the electron in the process of solvation. Instead the tunnelling nuclei typically appear to be next nearest neighbors to the trapped electron. The identities of the tunnelling nuclei have been deduced by isotopic substitution and are attributed to: Na in 10 mol dm/sup -3/ NaOH aqueous glass, ethyl protons in ethanol glass, methyl protons in methanol glass and methyl protons in MTHF glass. For trapped hydrogen atoms in phosphoric acid, the phosphorus nuclei appear to be the effective tunnelling nuclei. Below approximately 10 K the spin lattice relaxation is dominated by a temperature independent cross relaxation term for H atoms in phosphoric acid glass and for electrons in 10 mol dm/sup -3/ NaOH aqueous glass, but not for electrons in organic glasses. This is compared with recent electron-electron double resonance studies of cross relaxation in these glasses. The spin lattice relaxation of O/sup -/ formed in 10 mol dm/sup -3/ NaOH aqueous glass was also studied and found to be mainly dominated by a Raman process with an effective Debye temperature of about 100 K.

  7. Experimental Summary: Very High Energy Cosmic Rays and their Interactions

    Directory of Open Access Journals (Sweden)

    Kampert Karl-Heinz

    2013-06-01

    Full Text Available The XVII International Symposium on Very High Energy Cosmic Ray Interactions, held in August of 2012 in Berlin, was the first one in the history of the Symposium,where a plethora of high precision LHC data with relevance for cosmic ray physics was presented. This report aims at giving a brief summary of those measurements andit discusses their relevance for observations of high energy cosmic rays. Enormous progress has been made also in air shower observations and in direct measurements of cosmic rays, exhibiting many more structure in the cosmic ray energy spectrum than just a simple power law with a knee and an ankle. At the highest energy, the flux suppression may not be dominated by the GZK-effect but by the limiting energy of a nearby source or source population. New projects and application of new technologies promise further advances also in the near future. We shall discuss the experimental and theoretical progress in the field and its prospects for coming years.

  8. Depth of interaction detection for {gamma}-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lerche, Ch.W. [Instituto de Aplicaciones de las Tecnologias de la Informacion y de las Comunicaciones Avanzadas, (UPV) Camino de Vera s/n, E46022 (Spain)], E-mail: lerche@ific.uv.es; Doering, M. [Institut fuer Kernphysik, Forschungszentrum Juelich GmbH, D52425 Juelich (Germany); Ros, A. [Institute de Fisica Corpuscular (CSIC-UV), 22085, Valencia E46071 (Spain); Herrero, V.; Gadea, R.; Aliaga, R.J.; Colom, R.; Mateo, F.; Monzo, J.M.; Ferrando, N.; Toledo, J.F.; Martinez, J.D.; Sebastia, A. [Instituto de Aplicaciones de las Tecnologias de la Informacion y de las Comunicaciones Avanzadas, (UPV) Camino de Vera s/n, E46022 (Spain); Sanchez, F.; Benlloch, J.M. [Institute de Fisica Corpuscular (CSIC-UV), 22085, Valencia E46071 (Spain)

    2009-03-11

    A novel design for an inexpensive depth of interaction capable detector for {gamma}-ray imaging has been developed. The design takes advantage of the strong correlation between the width of the scintillation light distribution in monolithic crystals and the interaction depth of {gamma}-rays. We present in this work an inexpensive modification of the commonly used charge dividing circuits which enables the instantaneous and simultaneous computation of the second order moment of light distribution. This measure provides a good estimate for the depth of interaction and does not affect the determination of the position centroids and the energy release of {gamma}-ray impact. The method has been tested with a detector consisting of a monolithic LSO block sized 42x42x10mm{sup 3} and a position-sensitive photomultiplier tube H8500 from Hamamatsu. The mean spatial resolution of the detector was found to be 3.4mm for the position centroids and 4.9mm for the DOI. The best spatial resolutions were observed at the center of the detector and yielded 1.4mm for the position centroids and 1.9mm for the DOI.

  9. Depth of interaction detection for γ-ray imaging

    International Nuclear Information System (INIS)

    Lerche, Ch.W.; Doering, M.; Ros, A.; Herrero, V.; Gadea, R.; Aliaga, R.J.; Colom, R.; Mateo, F.; Monzo, J.M.; Ferrando, N.; Toledo, J.F.; Martinez, J.D.; Sebastia, A.; Sanchez, F.; Benlloch, J.M.

    2009-01-01

    A novel design for an inexpensive depth of interaction capable detector for γ-ray imaging has been developed. The design takes advantage of the strong correlation between the width of the scintillation light distribution in monolithic crystals and the interaction depth of γ-rays. We present in this work an inexpensive modification of the commonly used charge dividing circuits which enables the instantaneous and simultaneous computation of the second order moment of light distribution. This measure provides a good estimate for the depth of interaction and does not affect the determination of the position centroids and the energy release of γ-ray impact. The method has been tested with a detector consisting of a monolithic LSO block sized 42x42x10mm 3 and a position-sensitive photomultiplier tube H8500 from Hamamatsu. The mean spatial resolution of the detector was found to be 3.4mm for the position centroids and 4.9mm for the DOI. The best spatial resolutions were observed at the center of the detector and yielded 1.4mm for the position centroids and 1.9mm for the DOI.

  10. Gamma-Ray imaging for nuclear security and safety: Towards 3-D gamma-ray vision

    Science.gov (United States)

    Vetter, Kai; Barnowksi, Ross; Haefner, Andrew; Joshi, Tenzing H. Y.; Pavlovsky, Ryan; Quiter, Brian J.

    2018-01-01

    The development of portable gamma-ray imaging instruments in combination with the recent advances in sensor and related computer vision technologies enable unprecedented capabilities in the detection, localization, and mapping of radiological and nuclear materials in complex environments relevant for nuclear security and safety. Though multi-modal imaging has been established in medicine and biomedical imaging for some time, the potential of multi-modal data fusion for radiological localization and mapping problems in complex indoor and outdoor environments remains to be explored in detail. In contrast to the well-defined settings in medical or biological imaging associated with small field-of-view and well-constrained extension of the radiation field, in many radiological search and mapping scenarios, the radiation fields are not constrained and objects and sources are not necessarily known prior to the measurement. The ability to fuse radiological with contextual or scene data in three dimensions, in analog to radiological and functional imaging with anatomical fusion in medicine, provides new capabilities enhancing image clarity, context, quantitative estimates, and visualization of the data products. We have developed new means to register and fuse gamma-ray imaging with contextual data from portable or moving platforms. These developments enhance detection and mapping capabilities as well as provide unprecedented visualization of complex radiation fields, moving us one step closer to the realization of gamma-ray vision in three dimensions.

  11. Nuclear gamma-ray laser: the evolution of the idea

    International Nuclear Information System (INIS)

    Rivlin, Lev A

    2007-01-01

    The evolution of the foreign and native search for solving the problem of a nuclear gamma-ray laser (NGL), which has been attracting attention for almost half a century despite the absence at present of any convincing data about its experimental solution, is considered. It is shown that the key conflict inherent in any conception of the NGL is the antagonism between the necessity to accumulate a sufficient amount of excited nuclei and the requirement to narrow down the emission gamma-ray line to its natural radiative width. The critical analysis of different approaches for solving this conflict (Moessbauer scheme, deeply cooled ensembles of free nuclei with the hidden inversion, nuclear inversionless amplification, two-quantum gamma emission in counterpropagating photon beams, hypothetical amplifying medium of long-lived isomers in a Bose-Einstein condensate) shows that this search is important not only due to the expected result, which could stimulate the development of quantum nucleonics as a new branch in physics, but also is of interest due to a variety of physical disciplines and experimental approaches used in this search. (invited paper)

  12. γ-rays as a probe to study nuclear dynamics and nuclear structure at intermediate energies

    International Nuclear Information System (INIS)

    Schutz, Y.

    1987-01-01

    The usefulness of gamma rays in nuclear physics is reviewed, and it is shown how they offer insight into the structure and damping of giant resonances, and how they can be used as an isospin filter. Results from inclusive and exclusive experiments at GANIL are discussed. It is stressed that although the production of high energy gamma rays in heavy ion reactions between 30 MeV/A and 86 MeV/A is understood qualitatively, most models fail in being more quantitative

  13. A mobile gamma ray spectrometer system for nuclear hazard mapping

    International Nuclear Information System (INIS)

    Smethurst, Mark A.

    2000-12-01

    The Geological Survey of Norway has developed a system for mobile gamma ray spectrometer surveying suitable for use in nuclear emergencies where potentially dangerous radioactive materials have been released into the environment. The measuring system has been designed for use with different kinds of transportation platforms. These include fixed-wing aircraft, helicopters and vans. The choice of transportation platform depends on the nature of the nuclear emergency. Widespread fallout from a distant source can be mapped quickly from the air while local sources of radiation can be delineated by a car-borne system. The measuring system processes gamma ray spectra in real time. The operator of the system is therefore able to guide surveying in accordance with meaningful data values and immediately report these values to decision making authorities. The operator is presented with a number of different displays suited to different kinds of nuclear emergencies that lead to more efficient surveying. Real time processing of data means that the results of a survey can be delivered to decision makers immediately upon return to base. It is also possible to deliver data via a live mobile telephone link while surveying is underway. The measuring system can be adjusted to make measurements lasting between 1 second and 5 seconds. The spatial density of measuring positions depends on the duration of each measurement and the speed of travel of the measuring system. Measuring with 1 s intervals while travelling at 50 km/h in a car results in a measurement every 14 m along the road. Measuring with 1 s intervals in an aeroplane travelling at 250 km/h produces a measurement for every 70 m travelled. Eight hours surveying can produce up to 30000 measurements over a region hundreds of kilometres across. (Author)

  14. Neutrino interactions, proton production and a nuclear effect

    International Nuclear Information System (INIS)

    Guy, J.; Allport, P.P.; Cooper-Sarkar, A.; Sansum, R.A.; Venus, W.; Berggren, M.; Morrison, D.R.O.; Parker, M.A.; Wachsmuth, H.; Clayton, E.F.; Mobayyen, M.M.; Hulth, P.O.; Katz, U.; Wittek, W.; Marage, P.; Sacton, J.; Matsinos, E.; Simopoulou, E.; Myatt, G.; Neveu, M.; Apeldoorn, G.W. van

    1989-01-01

    Neutrino interactions are classified by the presence or absence of protons with momentum below 600 MeV/c at the interaction vertex. Interactions producing protons have softer x distributions for hydrogen and deuterium targets as well as for neon. In contrast to a recent claim, the effect is therefore not directly related to any nuclear effect in neon. (orig.)

  15. Neutrino interactions, proton production and a nuclear effect

    Science.gov (United States)

    Guy, J.; Allport, P. P.; Berggren, M.; Clayton, E. F.; Cooper-Sarkar, A.; Hulth, P. O.; Jones, G. T.; Katz, U.; Marage, P.; Matsinos, E.; Mobayyen, M. M.; Morrison, D. R. O.; Myatt, G.; Neveu, M.; O'Neale, S.; Parker, M. A.; Sacton, J.; Sansum, R. A.; Simopoulou, E.; van Apeldoorn, G. W.; Varvell, K.; Venus, W.; Wachsmuth, H.; Wittek, W.

    1989-10-01

    Neutrino interactions are classified by the presence or absence of protons with momentum below 600 MeV/c at the interaction vertex. Interactions producing protons have softer x distributions for hydrogen and deuterium targets as well as for neon. In contrast to a recent claim, the effect is therefore not directly related to any nuclear effect in neon.

  16. Dependence of X-Ray Burst Models on Nuclear Masses

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, H.; Ong, W.-J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States)

    2017-08-01

    X-ray burst model predictions of light curves and the final composition of the nuclear ashes are affected by uncertain nuclear masses. However, not all of these masses are determined experimentally with sufficient accuracy. Here we identify the remaining nuclear mass uncertainties in X-ray burst models using a one-zone model that takes into account the changes in temperature and density evolution caused by changes in the nuclear physics. Two types of bursts are investigated—a typical mixed H/He burst with a limited rapid proton capture process (rp-process) and an extreme mixed H/He burst with an extended rp-process. When allowing for a 3 σ variation, only three remaining nuclear mass uncertainties affect the light-curve predictions of a typical H/He burst ({sup 27}P, {sup 61}Ga, and {sup 65}As), and only three additional masses affect the composition strongly ({sup 80}Zr, {sup 81}Zr, and {sup 82}Nb). A larger number of mass uncertainties remain to be addressed for the extreme H/He burst, with the most important being {sup 58}Zn, {sup 61}Ga, {sup 62}Ge, {sup 65}As, {sup 66}Se, {sup 78}Y, {sup 79}Y, {sup 79}Zr, {sup 80}Zr, {sup 81}Zr, {sup 82}Zr, {sup 82}Nb, {sup 83}Nb, {sup 86}Tc, {sup 91}Rh, {sup 95}Ag, {sup 98}Cd, {sup 99}In, {sup 100}In, and {sup 101}In. The smallest mass uncertainty that still impacts composition significantly when varied by 3 σ is {sup 85}Mo with 16 keV uncertainty. For one of the identified masses, {sup 27}P, we use the isobaric mass multiplet equation to improve the mass uncertainty, obtaining an atomic mass excess of −716(7) keV. The results provide a roadmap for future experiments at advanced rare isotope beam facilities, where all the identified nuclides are expected to be within reach for precision mass measurements.

  17. Consideration on the interaction between society and nuclear technology

    International Nuclear Information System (INIS)

    Shinoda, Yoshihiko

    2007-01-01

    A social conflict over nuclear technology arises from the different interactions between society and nuclear technology. The purpose of this review is to grasp the essential points of this social conflict from a social viewpoint. These essential points can be discerned by interpreting results of polls about nuclear technology and the future of society in general. As a result, attitudes towards nuclear technology can be explained in terms of differences of general views on society such as social order or social progress. The attitudes of people toward nuclear technology were divided into strong agreement, weak agreement, weak objection and strong objection in order to obtain useful information for clarification of social conflict on this issue. Results of polls of people who have weak agreement for nuclear technology reveal their ambivalence about nuclear technology. This raises concern that further implementation of nuclear technology might cause these people to shift their views to objection. (author)

  18. The Dawn of Nuclear Photonics with Laser-based Gamma-rays

    International Nuclear Information System (INIS)

    Barty, C.J.

    2011-01-01

    A renaissance in nuclear physics is occurring around the world because of a new kind of incredibly bright, gamma-ray light source that can be created with short pulse lasers and energetic electron beams. These highly Mono-Energetic Gamma-ray (MEGa-ray) sources produce narrow, laser-like beams of incoherent, tunable gamma-rays and are enabling access and manipulation of the nucleus of the atom with photons or so called 'Nuclear Photonics'. Just as in the early days of the laser when photon manipulation of the valence electron structure of the atom became possible and enabling to new applications and science, nuclear photonics with laser-based gamma-ray sources promises both to open up wide areas of practical isotope-related, materials applications and to enable new discovery-class nuclear science. In the United States, the development of high brightness and high flux MEGa-ray sources is being actively pursued at the Lawrence Livermore National Laboratory in Livermore (LLNL), California near San Francisco. The LLNL work aims to create by 2013 a machine that will advance the state of the art with respect to source the peak brightness by 6 orders of magnitude. This machine will create beams of 1 to 2.3 MeV photons with color purity matching that of common lasers. In Europe a similar but higher photon energy gamma source has been included as part of the core capability that will be established at the Extreme Light Infrastructure Nuclear Physics (ELI-NP) facility in Magurele, Romania outside of Bucharest. This machine is expected to have an end point gamma energy in the range of 13 MeV. The machine will be co-located with two world-class, 10 Petawatt laser systems thus allowing combined intense-laser and gamma-ray interaction experiments. Such capability will be unique in the world. In this talk, Dr. Chris Barty from LLNL will review the state of the art with respect to MEGa-ray source design, construction and experiments and will describe both the ongoing projects

  19. Ultraviolet-x-ray interaction: mutation and transformation

    International Nuclear Information System (INIS)

    Han, A.; Elkind, M.M.; Suzuki, F.; Dainko, J.L.; Buess, E.

    1981-01-01

    The overall long-range objectives of the proposed research are to: (1) determine whether ionizing and nonionizing radiations interact in the induction of mutation and neoplastic transformation; (2) identify the nature of the interaction; (3) establish the possible relationship between the repair processes and the expression of interactive damage related to mutation and neoplastic transformation. Principal methods were used to assess survival, mutation, and neoplastic transformation of mammalian cells in culture. Cells were exposed to the following radiations: 50-kV x-rays; light from a germicidal lamp, uv-C (254 nm); light from unfiltered sun lamps, uv-B (290 to 345 nm); and light from sun lamps filtered by polystyrene dish covers

  20. Crystal diffraction lens telescope for focusing nuclear gamma rays

    International Nuclear Information System (INIS)

    Smither, R.K.; Fernandez, P.B.; Graber, T.; Faiz, M.

    1996-08-01

    A crystal diffraction lens was constructed at Argonne National Laboratory for use as a telescope to focus nuclear gamma rays. It consisted of 600 single crystals of germanium arranged in 8 concentric rings. The mounted angle of each crystal was adjusted to intercept and diffract the incoming gamma rays with an accuracy of a few arc sec. The performance of the lens was tested in two ways. In one case, the gamma rays were focused on a single medium size germanium detector. In the second case, the gamma rays were focused on the central germanium detector of a 3 x 3 matrix of small germanium detectors. The efficiency, image concentration and image quality, and shape were measured. The tests performed with the 3 x 3 matrix detector system were particularly interesting. The wanted radiation was concentrated in the central detector. The 8 other detectors were used to detect the Compton scattered radiation, and their energy was summed with coincident events in the central detector. This resulted in a detector with the efficiency of a large detector (all 9 elements) and the background of a small detector (only the central element). The use of the 3 x 3 detector matrix makes it possible to tell if the source is off axis and, if so, to tell in which direction. The crystal lens acts very much like a simple convex lens for visible light. Thus if the source is off to the left then the image will focus off to the right illuminating the detector on the right side: telling one in which direction to point the telescope. Possible applications of this type of crystal lens to balloon and satellite experiments will be discussed

  1. Interactive high-resolution isosurface ray casting on multicore processors.

    Science.gov (United States)

    Wang, Qin; JaJa, Joseph

    2008-01-01

    We present a new method for the interactive rendering of isosurfaces using ray casting on multi-core processors. This method consists of a combination of an object-order traversal that coarsely identifies possible candidate 3D data blocks for each small set of contiguous pixels, and an isosurface ray casting strategy tailored for the resulting limited-size lists of candidate 3D data blocks. While static screen partitioning is widely used in the literature, our scheme performs dynamic allocation of groups of ray casting tasks to ensure almost equal loads among the different threads running on multi-cores while maintaining spatial locality. We also make careful use of memory management environment commonly present in multi-core processors. We test our system on a two-processor Clovertown platform, each consisting of a Quad-Core 1.86-GHz Intel Xeon Processor, for a number of widely different benchmarks. The detailed experimental results show that our system is efficient and scalable, and achieves high cache performance and excellent load balancing, resulting in an overall performance that is superior to any of the previous algorithms. In fact, we achieve an interactive isosurface rendering on a 1024(2) screen for all the datasets tested up to the maximum size of the main memory of our platform.

  2. The Highest Resolution X-ray View of the Nuclear Region of NGC 4151

    Science.gov (United States)

    Wang, Junfeng; Fabbiano, G.; Karovska, M.; Elvis, M.; Risaliti, G.; Zezas, A.; Mundell, C. G.

    2009-09-01

    We report high resolution imaging of the nucleus of the Seyfert 1 galaxy NGC 4151 obtained with a 50 ks Chandra HRC observation. The HRC image resolves the emission on spatial scales of 0.5 arcsec (30 pc), showing an extended X-ray morphology overall consistent with the narrow line region seen in optical line emission. Removal of the bright point-like nuclear source and image deconvolution technique both reveal X-ray enhancements that closely match the substructures seen in the HST [OIII] image and prominent knots in the radio jet. We find that most of the NLR clouds in NGC 4151 have [OIII] to soft X-ray ratio consistent with the values observed in NLRs of some Seyfert 2 galaxies, which indicates a uniform ionization parameter even at large radii and a density dependence ∝ r^{-2} as expected in the disk wind scenario. We examine various X-ray emission mechanisms of the radio jet and consider thermal emission from interaction between radio outflow and the NLR clouds the most probable origin for the X-ray emission associated with the jet.

  3. Nuclear reactions and self-shielding effects of gamma-ray database for nuclear materials

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, Mitsutane; Noda, Tetsuji [National Research Institute for Metals, Tsukuba, Ibaraki (Japan)

    2001-03-01

    A database for transmutation and radioactivity of nuclear materials is required for selection and design of materials used in various nuclear reactors. The database based on the FENDL/A-2.0 on the Internet and the additional data collected from several references has been developed in NRIM site of 'Data-Free-Way' on the Internet. Recently, the function predicted self-shielding effect of materials for {gamma}-ray was added to this database. The user interface for this database has been constructed for retrieval of necessary data and for graphical presentation of the relation between the energy spectrum of neutron and neutron capture cross section. It is demonstrated that the possibility of chemical compositional change and radioactivity in a material caused by nuclear reactions can be easily retrieved using a browser such as Netscape or Explorer. (author)

  4. Nuclear reactions and self-shielding effects of gamma-ray database for nuclear materials

    International Nuclear Information System (INIS)

    Fujita, Mitsutane; Noda, Tetsuji

    2001-01-01

    A database for transmutation and radioactivity of nuclear materials is required for selection and design of materials used in various nuclear reactors. The database based on the FENDL/A-2.0 on the Internet and the additional data collected from several references has been developed in NRIM site of 'Data-Free-Way' on the Internet. Recently, the function predicted self-shielding effect of materials for γ-ray was added to this database. The user interface for this database has been constructed for retrieval of necessary data and for graphical presentation of the relation between the energy spectrum of neutron and neutron capture cross section. It is demonstrated that the possibility of chemical compositional change and radioactivity in a material caused by nuclear reactions can be easily retrieved using a browser such as Netscape or Explorer. (author)

  5. Interaction of clouds with the hot interstellar medium (HIM) and cosmic rays

    International Nuclear Information System (INIS)

    Voelk, H.J.

    1983-01-01

    The modification, by cosmic rays, of the interaction of interstellar clouds with the ambient HIM is considered. Small clouds should still evaporate and thereby exclude cosmic rays if they do so without cosmic rays. The possible mass accretion of massice clouds is reduced by the pressure of the compressed cosmic rays. The consequences for diffuse galactic #betta#-ray emisison are discussed. (orig.)

  6. Interactions of cosmic rays in the atmosphere: growth curves revisited

    Energy Technology Data Exchange (ETDEWEB)

    Obermeier, A.; Boyle, P.; Müller, D. [Enrico Fermi Institute, University of Chicago, Chicago, IL 60637 (United States); Hörandel, J., E-mail: a.obermeier@astro.ru.nl [Radboud Universiteit Nijmegen, 6525-HP Nijmegen (Netherlands)

    2013-12-01

    Measurements of cosmic-ray abundances on balloons are affected by interactions in the residual atmosphere above the balloon. Corrections for such interactions are particularly important for observations of rare secondary particles such as boron, antiprotons, and positrons. These corrections either can be calculated if the relevant cross sections in the atmosphere are known or may be empirically determined by extrapolation of the 'growth curves', i.e., the individual particle intensities as functions of atmospheric depth. The growth-curve technique is particularly attractive for long-duration balloon flights where the periodic daily altitude variations permit rather precise determinations of the corresponding particle intensity variations. We determine growth curves for nuclei from boron (Z = 5) to iron (Z = 26) using data from the 2006 Arctic balloon flight of the TRACER detector for cosmic-ray nuclei, and we compare the growth curves with predictions from published cross section values. In general, good agreement is observed. We then study the boron/carbon abundance ratio and derive a simple and energy-independent correction term for this ratio. We emphasize that the growth-curve technique can be developed further to provide highly accurate tests of published interaction cross section values.

  7. Ray-theory approach to electrical-double-layer interactions.

    Science.gov (United States)

    Schnitzer, Ory

    2015-02-01

    A novel approach is presented for analyzing the double-layer interaction force between charged particles in electrolyte solution, in the limit where the Debye length is small compared with both interparticle separation and particle size. The method, developed here for two planar convex particles of otherwise arbitrary geometry, yields a simple asymptotic approximation limited to neither small zeta potentials nor the "close-proximity" assumption underlying Derjaguin's approximation. Starting from the nonlinear Poisson-Boltzmann formulation, boundary-layer solutions describing the thin diffuse-charge layers are asymptotically matched to a WKBJ expansion valid in the bulk, where the potential is exponentially small. The latter expansion describes the bulk potential as superposed contributions conveyed by "rays" emanating normally from the boundary layers. On a special curve generated by the centers of all circles maximally inscribed between the two particles, the bulk stress-associated with the ray contributions interacting nonlinearly-decays exponentially with distance from the center of the smallest of these circles. The force is then obtained by integrating the traction along this curve using Laplace's method. We illustrate the usefulness of our theory by comparing it, alongside Derjaguin's approximation, with numerical simulations in the case of two parallel cylinders at low potentials. By combining our result and Derjaguin's approximation, the interaction force is provided at arbitrary interparticle separations. Our theory can be generalized to arbitrary three-dimensional geometries, nonideal electrolyte models, and other physical scenarios where exponentially decaying fields give rise to forces.

  8. Effective interaction: From nuclear reactions to neutron stars

    Indian Academy of Sciences (India)

    pact stars. The nuclear EoS for β-equilibrated neutron star (NS) matter obtained using density-dependent effective nucleon–nucleon interaction satisfies the constraints from the observed flow data from heavy-ion collisions. The energy density of quark matter is lower than that of the nuclear EoS at higher densities implying ...

  9. Muon Production in Relativistic Cosmic-Ray Interactions

    International Nuclear Information System (INIS)

    Klein, Spencer R.

    2009-01-01

    Cosmic-rays with energies up to 3x10 20 eV have been observed. The nuclear composition of these cosmic rays is unknown but if the incident nuclei are protons then the corresponding center of mass energy is √(s nn )=700TeV. High energy muons can be used to probe the composition of these incident nuclei. The energy spectra of high-energy (>1TeV) cosmic ray induced muons have been measured with deep underground or under-ice detectors. These muons come from pion and kaon decays and from charm production in the atmosphere. Terrestrial experiments are most sensitive to far-forward muons so the production rates are sensitive to high-x partons in the incident nucleus and low-x partons in the nitrogen/oxygen targets. Muon measurements can complement the central-particle data collected at colliders. This paper will review muon production data and discuss some non-perturbative (soft) models that have been used to interpret the data. I will show measurements of TeV muon transverse momentum (p T ) spectra in cosmic-ray air showers from MACRO, and describe how the IceCube neutrino observatory and the proposed Km3Net detector will extend these measurements to a higher p T region where perturbative QCD should apply. With a 1 km 2 surface area, the full IceCube detector should observe hundreds of muons/year with p T in the pQCD regime.

  10. Gamma ray shielding: a web based interactive program

    International Nuclear Information System (INIS)

    Subbaiah, K.V.; Senthi Kumar, C.; Sarangapani, R.

    2005-01-01

    A web based interactive computing program is developed using java for quick assessment of Gamma Ray shielding problems. The program addresses usually encountered source geometries like POINT, LINE, CYLINDRICAL, ANNULAR, SPHERICAL, BOX, followed by 'SLAB' shield configurations. The calculation is based on point kernel technique. The source points are randomly sampled within the source volume. From each source point, optical path traversed in the source and shield media up to the detector location is estimated to calculate geometrical and material attenuations, and then corresponding buildup factor is obtained, which accounts for scattered contribution. Finally, the dose rate for entire source is obtained by summing over all sampled points. The application allows the user to select one of the seven regular geometrical bodies and provision exist to give source details such as emission energies, intensities, physical dimensions and material composition. Similar provision is provided to specify shield slab details. To aid the user, atomic numbers, densities, standard build factor materials and isotope list with respective emission energies and intensity for ready reference are given in dropdown combo boxes. Typical results obtained from this program are validated against existing point kernel gamma ray shielding codes. Additional facility is provided to compute fission product gamma ray source strengths based on the fuel type, burn up and cooling time. Plots of Fission product gamma ray source strengths, Gamma ray cross-sections and buildup factors can be optionally obtained, which enable the user to draw inference on the computed results. It is expected that this tool will be handy to all health physicists and radiological safety officers as it will be available on the internet. (author)

  11. On deep inelastic lepton-nuclear interactions

    International Nuclear Information System (INIS)

    Garsevanishvili, V.R.; Darbaidze, Ya.Z.; Menteshashvili, Z.R.; Ehsakiya, Sh.M.

    1981-01-01

    The problem of building relativistic theory of nuclear reactions by way of involving relativistic methods, developed in the elementary particle theory, becomes rather actual at the time being. The paper presents some results of investigations into deep inelastic lepton-nuclear processes lA → l'(A-1)x, with the spectator nucleus-fragment in the finite state. To describe the reactions lA → l'(A-1)x (where l=an electron, muan, neutrino, antineutrino), the use is made of the self-similarity principle and multiparticle quasipotential formalism in the ''light front'' variables. The expressions are obtained for the differential cross-sections of lepton-nuclear processes and for the structure functions of deep inelastic scattering of neutrinos (antineutrinos) and charged leptons by nuclei

  12. Prompt gamma ray diagnostics and enhanced hadron-therapy using neutron-free nuclear reactions

    Science.gov (United States)

    Giuffrida, L.; Margarone, D.; Cirrone, G. A. P.; Picciotto, A.; Cuttone, G.; Korn, G.

    2016-10-01

    We propose a series of simulations about the potential use of Boron isotopes to trigger neutron-free (aneutronic) nuclear reactions in cancer cells through the interaction with an incoming energetic proton beam, thus resulting in the emission of characteristic prompt gamma radiation (429 keV, 718 keV and 1435 keV). Furthermore assuming that the Boron isotopes are absorbed in cancer cells, the three alpha-particles produced in each p-11B aneutronic nuclear fusion reactions can potentially result in the enhancement of the biological dose absorbed in the tumor region since these multi-MeV alpha-particles are stopped inside the single cancer cell, thus allowing to spare the surrounding tissues. Although a similar approach based on the use of 11B nuclei has been proposed in [Yoon et al. Applied Physics Letters 105, 223507 (2014)], our work demonstrate, using Monte Carlo simulations, the crucial importance of the use of 10B nuclei (in a solution containing also 11B) for the generation of prompt gamma-rays, which can be applied to medical imaging. In fact, we demonstrate that the use of 10B nuclei can enhance the intensity of the 718 keV gamma-ray peak more than 30 times compared to the solution containing only 11B nuclei. A detailed explanation of the origin of the different prompt gamma-rays, as well as of their application as real-time diagnostics during a potential cancer treatment, is here discussed.

  13. New studies of nuclear decay γ-rays from novae

    International Nuclear Information System (INIS)

    Starrfield, S.; Truran, J.W.; Wiescher, M.C.; Sparks, W.M.

    1997-01-01

    The cause of the nova outburst is a thermonuclear runaway (TNR) in hydrogen rich material transferred by a companion onto a white dwarf. Studies of this phenomenon have shown that the TNR produces large concentrations of the short lived positron unstable isotopes of the CNO nuclei which are transported to the surface by convection so that early in the outburst we expect significant numbers of radioactive decays to occur at the surface. The resulting γ-ray emission may be detectable from nearby novae early in their outbursts. The TNR is also expected to produce substantial amounts of 7 Be and 22 Na. Their decays also yield potentially detectable levels of γ-ray emission for relatively nearby novae. We are also interested in the role played by novae in the production of the ∼2M circle-dot of 26 Al found in the galaxy. In order to improve our predictions of this phenomenon, we have performed a new set of calculations of TNR close-quote s on ONeMg and CO white dwarfs with an updated nuclear reaction network and opacities. copyright 1997 American Institute of Physics

  14. Characterising legacy spent nuclear fuel pond materials using microfocus X-ray absorption spectroscopy.

    Science.gov (United States)

    Bower, W R; Morris, K; Mosselmans, J F W; Thompson, O R; Banford, A W; Law, K; Pattrick, R A D

    2016-11-05

    Analysis of a radioactive, coated concrete core from the decommissioned, spent nuclear fuel cooling pond at the Hunterston-A nuclear site (UK) has provided a unique opportunity to study radionuclides within a real-world system. The core, obtained from a dividing wall and sampled at the fill level of the pond, exhibited radioactivity (dominantly (137)Cs and (90)Sr) heterogeneously distributed across both painted faces. Chemical analysis of the core was undertaken using microfocus spectroscopy at Diamond Light Source, UK. Mapping of Sr across the surface coatings using microfocus X-ray fluorescence (μXRF) combined with X-ray absorption spectroscopy showed that Sr was bound to TiO2 particles in the paint layers, suggesting an association between TiO2 and radiostrontium. Stable Sr and Cs sorption experiments using concrete coupons were also undertaken to assess their interactions with the bulk concrete in case of a breach in the coating layers. μXRF and scanning electron microscopy showed that Sr was immobilized by the cement phases, whilst at the elevated experimental concentrations, Cs was associated with clay minerals in the aggregates. This study provides a crucial insight into poorly understood infrastructural contamination in complex systems and is directly applicable to the UK's nuclear decommissioning efforts. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Information Interaction with IAEA on Nuclear Import and Export

    International Nuclear Information System (INIS)

    Osokina, A.; Snytnikov, A.

    2015-01-01

    This paper considers organizational aspects of nuclear import and export interaction between the Russian Federation and the Agency. Requirements of nuclear import and export in Russia, information submission procedure and forms are determined in RF Government Regulation No 973 from December 15th 2000. Particularly, according to these requirements Russian licenced organizations implementing nuclear import and export submit reports about appointed transfers to State Corporation 'Rosatom'. Regulations of State Corporation 'Rosatom' entrusted gathering and processing of reporting information and interaction with IAEA to FSUE 'SCC of Rosatom'. Regulations of reporting information interaction were developed by SCC and approved by State Corporation 'Rosatom'. Russian organizations send notifications to SCC using regulation electron or paper forms. Regulations determine information security measures in reporting process. Automated nuclear import and export accounting system developed by SCC provides data entering, keeping and processing, enables to choose and submit requested information in different formats. This system is integrated with State Nuclear Material Control and Accounting System. Also submitted information is regularly compared with customs declarations data to improve reliability and consistency of information. Generalized nuclear import and export data is using by Departments of State Corporation 'Rosatom' and transmitting to Federal Environmental, Industrial and Nuclear Supervision Service of Russia in agreed forms. Summary information about international nuclear transfers is sending to IAEA according to INFCIRC/207. Reporting information is coordinating. Messaging with IAEA is realized by email using enciphering program. (author)

  16. The weak interaction in nuclear, particle and astrophysics

    International Nuclear Information System (INIS)

    Grotz, K.; Klapdor, H.V.

    1989-01-01

    This book is an introduction to the concepts of weak interactions and their importance and consequences for nuclear physics, particle physics, neutrino physics, astrophysics and cosmology. After a general introduction to elementary particles and interactions the Fermi theory of weak interactions is described together with its connection with nuclear structure and beta decay including the double beta decay. Then, after a general description of gauge theories the Weinberg-Salam theory of the electroweak interactions is introduced. Thereafter the weak interactions are considered in the framework of grand unification. Then the physics of neutrinos is discussed. Thereafter connections of weak interactions with astrophysics are considered with special regards to the gravitational collapse and the synthesis of heavy elements in the r-process. Finally, the connections of grand unified theories and cosmology are considered. (HSI) With 141 figs., 39 tabs

  17. Landau parameters for finite range density dependent nuclear interactions

    International Nuclear Information System (INIS)

    Farine, M.

    1997-01-01

    The Landau parameters represent the effective particle-hole interaction at Fermi level. Since between the physical observables and the Landau parameters there is a direct relation their derivation from an effective interaction is of great interest. The parameter F 0 determines the incompressibility K of the system. The parameter F 1 determines the effective mass (which controls the level density at the Fermi level). In addition, F 0 ' determines the symmetry energy, G 0 the magnetic susceptibility, and G 0 ' the pion condensation threshold in nuclear matter. This paper is devoted to a general derivation of Landau parameters for an interaction with density dependent finite range terms. Particular carefulness is devoted to the inclusion of rearrangement terms. This report is part of a larger project which aims at defining a new nuclear interaction improving the well-known D1 force of Gogny et al. for describing the average nuclear properties and exotic nuclei and satisfying, in addition, the sum rules

  18. The collective Lamb shift in nuclear γ-ray superradiance

    International Nuclear Information System (INIS)

    Röhlsberger, Ralf

    2012-01-01

    The electromagnetic transitions of Mössbauer nuclei provide almost ideal two-level systems to transfer quantum optical concepts into the regime of hard x-rays. If many identical atoms collectively interact with a resonant radiation field, one observes (quantum) optical properties that are strongly different from those of a single atom. The most prominent effect is the broadening of the resonance line known as collective enhancement, resulting from multiple scattering of real photons within the atomic ensemble. On the other hand, the exchange of virtual photons within the ensemble leads to a tiny energy shift of the resonance line, the collective Lamb shift, that remained experimentally elusive for a long time after its prediction. Here we illustrate how highly brilliant synchrotron radiation allows one to prepare superradiant states of excited Mössbauer nuclei, an important condition for observation of the collective Lamb shift.

  19. Characterising legacy spent nuclear fuel pond materials using microfocus X-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bower, W.R. [Research Centre for Radwaste Disposal, School of Earth and Environmental Sciences, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); National Nuclear Laboratory, Chadwick House, Warrington Road, Birchwood Park, Warrington, WA3 6AE (United Kingdom); Centre for Radiochemistry Research, Chemistry Building, The University of Manchester, Brunswick Street, Manchester M13 9PL (United Kingdom); Morris, K. [Research Centre for Radwaste Disposal, School of Earth and Environmental Sciences, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Mosselmans, J.F.W. [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom); Thompson, O.R. [National Nuclear Laboratory, Chadwick House, Warrington Road, Birchwood Park, Warrington, WA3 6AE (United Kingdom); Banford, A.W. [National Nuclear Laboratory, Chadwick House, Warrington Road, Birchwood Park, Warrington, WA3 6AE (United Kingdom); School of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom); Law, K. [Centre for Radiochemistry Research, Chemistry Building, The University of Manchester, Brunswick Street, Manchester M13 9PL (United Kingdom); Pattrick, R.A.D., E-mail: richard.pattrick@manchester.ac.uk [Research Centre for Radwaste Disposal, School of Earth and Environmental Sciences, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom)

    2016-11-05

    Highlights: • A sample from a spent fuel pond wall has been analysed via X-ray spectroscopy. • Autoradiography shows a patchy distribution of radioactivity on the core face. • μXAS across a ‘hot spot’ showed Sr associates with the TiO{sub 2} pigment in the paint. • Original concrete coatings prove effective at limiting radionuclide migration. • Sorption studies show Sr immobilisation by the concrete and Cs by aggregate clasts. - Abstract: Analysis of a radioactive, coated concrete core from the decommissioned, spent nuclear fuel cooling pond at the Hunterston-A nuclear site (UK) has provided a unique opportunity to study radionuclides within a real-world system. The core, obtained from a dividing wall and sampled at the fill level of the pond, exhibited radioactivity (dominantly {sup 137}Cs and {sup 90}Sr) heterogeneously distributed across both painted faces. Chemical analysis of the core was undertaken using microfocus spectroscopy at Diamond Light Source, UK. Mapping of Sr across the surface coatings using microfocus X-ray fluorescence (μXRF) combined with X-ray absorption spectroscopy showed that Sr was bound to TiO{sub 2} particles in the paint layers, suggesting an association between TiO{sub 2} and radiostrontium. Stable Sr and Cs sorption experiments using concrete coupons were also undertaken to assess their interactions with the bulk concrete in case of a breach in the coating layers. μXRF and scanning electron microscopy showed that Sr was immobilized by the cement phases, whilst at the elevated experimental concentrations, Cs was associated with clay minerals in the aggregates. This study provides a crucial insight into poorly understood infrastructural contamination in complex systems and is directly applicable to the UK’s nuclear decommissioning efforts.

  20. Future prospects in n-nuclear interactions

    International Nuclear Information System (INIS)

    Moss, J.M.

    1982-01-01

    I examine in detail two research areas, polarization observables and antiproton-nucleus reactions, which should have near-term future impact on our understanding of the interaction of medium-energy nucleons in nuclei. More speculative future experiments employing cooled beams, double spectrometer systems, and large Q-valure low momentum-transfer reactions are also discussed

  1. Aqueous solutions/nuclear glasses interactions

    International Nuclear Information System (INIS)

    Delage, F.; Advocat, T.; Vernaz, E.; Crovisier, J.L.

    1991-01-01

    Interactions results of the borosilicate glass used in radioactive wastes confinement and aqueous solutions at various temperature and PH show that for the glass components: - the release rate evolution follows an Arrhenius law, - in acid PH, there is a selective dissolution, - in basic PH, there is a stoechiometric dissolution [fr

  2. A Prototype Scintillating Fibre Tracker for the Cosmic-Ray Muon Tomography of Legacy Nuclear Waste Containers

    OpenAIRE

    Kaiser, R.; Clarkson, A.; Hamilton, D. J.; Hoek, M.; Ireland, D.G.; Johnstone, J.R.; Keri, T.; Lumsden, S.; Mahon, D. F.; McKinnon, B.; Murray, M.; Nutbeam-Tuffs, S.; Shearer, C.; Staines, C.; Yang, G.

    2014-01-01

    Cosmic-ray muons are highly-penetrative charged particles observed at sea level with a flux of approximately 1 cm−2 min−1. They interact with matter primarily through Coulomb scattering which can be exploited in muon tomography to image objects within industrial nuclear waste containers. This paper presents the prototype scintillating-fibre detector developed for this application at the University of Glasgow. Experimental results taken with test objects are shown in comparison to results from...

  3. Photon interaction studies using 241Am γ-rays

    International Nuclear Information System (INIS)

    Ramachandran, N.; Karunakaran Nair, K.; Abdullah, K.K.; Varier, K.M.

    2006-01-01

    We have carried out some photon interaction measurements using 59.54 keV γ-rays from a 241 Am source. These include γ attenuation studies as well as photoelectric absorption studies in various samples. The attenuation studies have been made using leaf and wood samples, samples like sand, sugar etc., which contain particles of varying sizes as well as pellets and aqueous solutions of rare earth compounds. In the case of the leaf and wood samples, we have used the γ-ray attenuation technique for the determination of the water content in fresh and dried samples. The variation of the attenuation coefficient with particle size has been investigated for sand and sugar samples. The attenuation studies as well as the photoelectric studies in the case of rare earth elements have been carried out on samples containing such elements whose K-absorption edge energies lie below and close to the γ-energy used. Suitable compounds of the rare earth elements have been chosen as mixture absorbers in these investigations. A narrow beam good geometry set-up was used for the attenuation measurements. A well-shielded scattering geometry was used for the photoelectric measurements. The mixture rule was invoked to extract the values of the mass attenuation coefficients for the elements from those of the corresponding compounds. The results are consistent with theoretical values derived from the XCOM package. (author)

  4. The temperature pulse propagation in interacting nuclear slabs

    International Nuclear Information System (INIS)

    Kozlowski, M.; Zurich Univ.

    1989-01-01

    Following the method developed by R.J. Swenson a non-Fourier equation for heat transfer in nuclear matter is obtained. The velocity of heat propagation is calculated and the value υ s = υ F /√3 is obtained. For two interacting nuclear slabs the temperature as a function of time is calculated. For a nucleon mean free path λ ≅ 3 fm the temperature saturation time is calculated and the value ≅ 160 fm/c is obtained. (orig.)

  5. Interactive visual analysis of nuclear data with ZVView

    International Nuclear Information System (INIS)

    Zerkin, Viktor

    2002-01-01

    This paper describes the cross section graphics software package ZVVIEW that was developed for the evaluators to perform efficient interactive visual analysis of experimental and theoretical nuclear data. ZVVIEW is a very powerful and complete package that simplifies the presentation of nuclear cross section data. A CD-ROM version of this computer package is available from the IAEA-NDS on request. (a.n.)

  6. Combined Photoneutron And X Ray Interrogation Of Containers For Nuclear Materials

    Science.gov (United States)

    Gozani, Tsahi; Shaw, Timothy; King, Michael J.; Stevenson, John; Elsalim, Mashal; Brown, Craig; Condron, Cathie

    2011-06-01

    Effective cargo inspection systems for nuclear material detection require good penetration by the interrogating radiation, generation of a sufficient number of fissions, and strong and penetrating detection signatures. Inspection systems need also to be sensitive over a wide range of cargo types and densities encountered in daily commerce. Thus they need to be effective with highly hydrogenous cargo, where neutron attenuation is a major limitation, as well as with dense metallic cargo, where x-ray penetration is low. A system that interrogates cargo with both neutrons and x-rays can, in principle, achieve high performance over the widest range of cargos. Moreover, utilizing strong prompt-neutron (˜3 per fission) and delayed-gamma ray (˜7 per fission) signatures further strengthens the detection sensitivity across all cargo types. The complementary nature of x-rays and neutrons, used as both probing radiation and detection signatures, alleviates the need to employ exceedingly strong sources, which would otherwise be required to achieve adequate performance across all cargo types, if only one type of radiation probe were employed. A system based on the above principles, employing a commercially-available 9 MV linac was developed and designed. Neutrons are produced simultaneously with x-rays by the photonuclear interaction of the x-ray beam with a suitable converter. A total neutron yield on the order of 1011 n/s is achieved with an average electron beam current of 100 μA. If fissionable material is present, fissions are produced both by the high-energy x-ray beam and by the photoneutrons. Photofission and neutron fission dominate in hydrogenous and metallic cargos, respectively. Neutron-capture gamma rays provide information on the cargo composition. The prompt neutrons resulting from fission are detected by two independent detector systems: by very efficient Differential Die Away Analysis (DDAA) detectors, and by direct detection of neutrons with energies higher

  7. Nuclear medicine and the environment: radiation interactions

    International Nuclear Information System (INIS)

    Schmelter, R.F.

    1986-01-01

    The effect of radiation interactions on the environment may be considered from the perspective of the purely physical phenomena occurring or from the effects the interactions produce in organized biological systems. The physical processes by which radiation interacts with the environment are quite well defined. Although these processes differ depending upon the nature (either electromagnetic or particulate) of the primary radiation, the ultimate result is the production in the medium of high-speed, secondary charged particles. Some of the energy of these particles is absorbed by the medium, while a portion may be lost as bremsstrahlung. The energy that is absorbed produces excitation and ionization, which can be disruptive to biological systems. The effects produced by ionizing radiations at the biochemical, cellular, and organ level are less well defined. Nevertheless, available data indicate that certain generalizations are possible. For example, given the ubiquitous nature of water in tissues, macromolecules, regardless of their structural types, tend to serve as acceptors of the energy and products of water radiolysis. However, a deeper insight into the consequences of irradiation requires an understanding of the interplay of such parameters as the type and energy of the radiation, and the dose and rate of its application. Furthermore, at the cellular level, the type and age of the irradiated cells, the concentration of oxygen in their environment, and their cell-cycle phase are all important factors in determining the consequences of irradiation. 72 references

  8. Lambda-nuclear interactions and hyperon puzzle in neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Haidenbauer, J. [Forschungszentrum Juelich, Institute for Advanced Simulation, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Universitaet Bonn, Helmholtz Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Meissner, U.G. [Universitaet Bonn, Helmholtz Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Forschungszentrum Juelich, Institute for Advanced Simulation, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Kaiser, N.; Weise, W. [Technische Universitaet Muenchen, Physik Department, Garching (Germany)

    2017-06-15

    Brueckner theory is used to investigate the in-medium properties of a Λ-hyperon in nuclear and neutron matter, based on hyperon-nucleon interactions derived within SU(3) chiral effective field theory (EFT). It is shown that the resulting Λ single-particle potential U{sub Λ}(p{sub Λ} = 0, ρ) becomes strongly repulsive for densities ρ of two-to-three times that of normal nuclear matter. Adding a density-dependent effective ΛN-interaction constructed from chiral ΛNN three-body forces increases the repulsion further. Consequences of these findings for neutron stars are discussed. It is argued that for hyperon-nuclear interactions with properties such as those deduced from the SU(3) EFT potentials, the onset for hyperon formation in the core of neutron stars could be shifted to much higher density which, in turn, could pave the way for resolving the so-called hyperon puzzle. (orig.)

  9. Considerations about soil-structures interaction in nuclear power plants

    International Nuclear Information System (INIS)

    Muzzi, F.

    1977-01-01

    The main features of the soil-structure interaction for nuclear power plant are presented as they resulted from conservations that the author carried out at the Berkeley (California) University, at the California Institute of Technology and at the U.S. Nuclear Regulatory Commission in Washington (Dec 1975). The complete and inertial interaction approaches of analysis are discussed. The complete approach by the use of finite element technique as suggested by the U.S.N.R.C. Standard Review Plan 3.7.1. (June 1975) is finally described. (author)

  10. High-intensity X-rays interaction with matter processes in plasmas, clusters, molecules and solids

    CERN Document Server

    Hau-Riege, Stefan P

    2012-01-01

    Filling the need for a book bridging the effect of matter on X-ray radiation and the interaction of x-rays with plasmas, this monograph provides comprehensive coverage of the topic. As such, it presents and explains such powerful new X-ray sources as X-ray free-electron lasers, as well as short pulse interactions with solids, clusters, molecules, and plasmas, and X-ray matter interactions as a diagnostic tool. Equally useful for researchers and practitioners working in the field.

  11. Nuclear electric quadrupole interactions in liquids entrapped in cavities

    Energy Technology Data Exchange (ETDEWEB)

    Furman, Gregory B., E-mail: gregoryf@bgu.ac.il; Meerovich, Victor M.; Sokolovsky, Vladimir L. [Ben Gurion University of the Negev, Physics Department (Israel)

    2016-12-15

    Liquids entrapped in cavities and containing quadrupole nuclei are considered. The interaction of the quadrupole moment of a nucleus with the electric field gradient is studied. In such a system, molecules are in both rotational and translational Brownian motions which are described by the diffusion equation. Solving this equation, we show that the intra- and intermolecular nuclear quadrupole interactions are averaged to zero in cavities with the size larger than several angstroms.

  12. Searches for exotic interactions in nuclear beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Naviliat-Cuncic, O. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, 640 S Shaw Lane, East Lansing MI 48824 (United States)

    2016-07-07

    This contribution presents current efforts in the search for exotic interactions in nuclear β decay using a calorimetric technique for the measurement of the β energy spectrum shape. We describe the criteria for the choice of sensitive candidates in Gamow-Teller transitions and present the status of measurements performed in {sup 6}He and {sup 20}F decay.

  13. Pure nuclear reflexes and combined hyperfine interactions in YIG

    Energy Technology Data Exchange (ETDEWEB)

    Winkler, H; Eisberg, R; Alp, E; Rueffer, R; Gerdau, E; Lauer, S; Trautwein, A X; Grodzicki, M; Vera, A

    1983-01-01

    Moessbauer spectra of oriented YIG single crystals were taken and the numerical analysis using the transmission integral yielded a consistent set of hyperfine interaction parameters. They are in good agreement with theoretical values obtained by MO-calculations which included clusters up to 62 ions. Finally pure nuclear reflexes are predicted for single crystals and two theoretical spectra are given.

  14. Static and Covariant Meson-Exchange Interactions in Nuclear Matter

    International Nuclear Information System (INIS)

    Carlson, B.V.; Hirata, D.

    2011-01-01

    The Dirac version of static meson exchange interactions provides a good description of low-energy NN scattering as well as very reasonable saturation properties in Dirac-Brueckner calculations of nuclear matter. We include retardation terms to make these interactions covariant and readjust the coupling constants so as to maintain a reasonable description of NN scattering. In this case, we find the Dirac-Brueckner approximation to nuclear matter to be extremely overbound. The Bonn meson-exchange interactions provide a good fit to low-energy nucleon-nucleon scattering and the deuteron binding energy using a static interaction and the Thompson form of the reduced two-nucleon interaction. We have readjusted the coupling constants of the these interactions to obtain almost equivalent fits to the scattering data and deuteron binding energy with a static interaction and the Blankenbecler-Sugar form of the reduced two-nucleon propagator and using both forms of the propagator with a covariant interaction. Dirac-Brueckner calculations using the static interactions furnish saturation properties similar to those found for the Bonn interactions. The covariant interactions, on the contrary, yield extreme overbinding and do not show signs of saturation before our calculations diverge. One of the advantages claimed for Dirac mean field calculations over nonrelativistic ones has been the fact that they yield reasonable saturation properties without the necessity of a three-body interaction. This is usually credited to the three-body effects introduced by virtual scattering through the Dirac sea states. These are included, in part, through the Dirac form of the self-energy in our calculations. However, we have explicitly excluded their contribution to the Brueckner scattering kernel. Dirac-Brueckner calculations in which both the positive and negative energy states are included in the scattering kernel result in less binding than those that include only the positive-energy ones

  15. Accelerating Full Configuration Interaction Calculations for Nuclear Structure

    International Nuclear Information System (INIS)

    Yang, Chao; Sternberg, Philip; Maris, Pieter; Ng, Esmond; Sosonkina, Masha; Le, Hung Viet; Vary, James; Yang, Chao

    2008-01-01

    One of the emerging computational approaches in nuclear physics is the full configuration interaction (FCI) method for solving the many-body nuclear Hamiltonian in a sufficiently large single-particle basis space to obtain exact answers - either directly or by extrapolation. The lowest eigenvalues and corresponding eigenvectors for very large, sparse and unstructured nuclear Hamiltonian matrices are obtained and used to evaluate additional experimental quantities. These matrices pose a significant challenge to the design and implementation of efficient and scalable algorithms for obtaining solutions on massively parallel computer systems. In this paper, we describe the computational strategies employed in a state-of-the-art FCI code MFDn (Many Fermion Dynamics - nuclear) as well as techniques we recently developed to enhance the computational efficiency of MFDn. We will demonstrate the current capability of MFDn and report the latest performance improvement we have achieved. We will also outline our future research directions

  16. Study on radiation damage of electron and γ-rays and mechanism of nuclear hardening

    International Nuclear Information System (INIS)

    Jing Tao

    2001-01-01

    Radiation damage effects of electrons and γ-rays are presented. The damage defects are studied by experimental methods. On the basis of these studies the damage mechanism and nuclear hardening techniques are studied

  17. Characterization of nuclear physics targets using Rutherford backscattering and particle induced X-ray emission

    International Nuclear Information System (INIS)

    Rubehn, T.; Wozniak, G.J.; Phair, L.; Moretto, L.G.; Yu, K.M.

    1997-01-01

    Rutherford backscattering and particle induced X-ray emission have been utilized to precisely characterize targets used in nuclear fission experiments. The method allows for a fast and non-destructive determination of target thickness, homogeneity and element composition. (orig.)

  18. Nuclear collisions in measurements of the cosmic ray charge spectrum with a counter telescope

    International Nuclear Information System (INIS)

    Lindstam, S.

    1975-06-01

    The importance of nuclear collisions of cosmic ray particles in a counter detector telescope is studied by simple Monte Carlo techniques. The interest concentrates on the charge region just below iron and the calculations are restricted to fully relativistic cosmic rays. It is found that it is difficult to avoid a blurring in the charge spectrum from nuclear collisions leading to considerable systematic errors in some abundance ratios. (Auth.)

  19. Nuclear Effects in Neutrino Interactions at Low Momentum Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Miltenberger, Ethan Ryan [Univ. of Minnesota, Minneapolis, MN (United States)

    2015-05-01

    This is a study to identify predicted effects of the carbon nucleus environment on neutrino - nucleus interactions with low momentum transfer. A large sample of neutrino interaction data collected by the MINERvA experiment is analyzed to show the distribution of charged hadron energy in a region with low momentum transfer. These distributions reveal a major discrepancy between the data and a popular interaction model with only the simplest Fermi gas nuclear effects. Detailed analysis of systematic uncertainties due to energy scale and resolution can account for only a little of the discrepancy. Two additional nuclear model effects, a suppression/screening effect (RPA), and the addition of a meson exchange current process (MEC), are shown to improve the description of the data.

  20. Nuclear matter from effective quark-quark interaction.

    Science.gov (United States)

    Baldo, M; Fukukawa, K

    2014-12-12

    We study neutron matter and symmetric nuclear matter with the quark-meson model for the two-nucleon interaction. The Bethe-Bruckner-Goldstone many-body theory is used to describe the correlations up to the three hole-line approximation with no extra parameters. At variance with other nonrelativistic realistic interactions, the three hole-line contribution turns out to be non-negligible and to have a substantial saturation effect. The saturation point of nuclear matter, the compressibility, the symmetry energy, and its slope are within the phenomenological constraints. Since the interaction also reproduces fairly well the properties of the three-nucleon system, these results indicate that the explicit introduction of the quark degrees of freedom within the considered constituent quark model is expected to reduce the role of three-body forces.

  1. Signatures of cosmic-ray interactions on the solar surface

    Science.gov (United States)

    Seckel, D.; Stanev, Todor; Gaisser, T. K.

    1991-01-01

    The fluxes of neutrinos, gamma rays, antiprotons, neutrons, and antineutrons that result from collisions of high-energy Galactic cosmic rays with the solar atmosphere are estimated. The results are sensitive to assumptions about cosmic-ray transport in the magnetic fields of the inner solar system. The high-energy photon flux should be observable by the Gamma Ray Observatory. The neutrino flux should produce less than one event per year in the next generation of neutrino telescopes. The antiproton flux is unobservable against the Galactic background. The neutron and antineutron fluxes are detectable only if neutrons produced in terrestrial cosmic-ray events may be discriminated against.

  2. Basics of Gamma Ray Detection

    Energy Technology Data Exchange (ETDEWEB)

    Stinnett, Jacob [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Venkataraman, Ram [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-09-13

    The objective of this training is to explain the origin of x-rays and gamma rays, gamma ray interactions with matter, detectors and electronics used in gamma ray-spectrometry, and features of a gamma-ray spectrum for nuclear material that is safeguarded.

  3. Spin-spin interactions of electrons and also of nucleons create atomic molecular and nuclear structures

    International Nuclear Information System (INIS)

    Kaliambos, L.A.

    2008-01-01

    Fundamental interactions of spinning electrons at an interelectron separation less than 578.8 fm yield attractive electromagnetic forces with S = 0 creating vibrations under a motional emf. They explain the indistinguishability of electrons and give a vibration energy able for calculating the ground-state energies of many-electron atoms without using any perturbative approximation. Such forces create two-electron orbitals able to account for the exclusion principal and the mechanism of covalent bonds. In the outer subshells of atoms the penetrating orbitals interact also as pair-pair systems and deform drastically the probability densities of the quantum mechanical electron clouds. Such a dynamics of deformation removes the degeneracy and leads to the deviation from the shell scheme. However in the interior of atoms the large nuclear charge leads to a spherically symmetric potential with non-interacting pairs for creating shells of degenerate states giving an accurate explanation of the X-ray lines. On the other hand, considerable charge distributions in nucleons as multiples of 2e/3 and - e/3 determined by the magnetic moments, interact for creating the nuclear structure with p-n bonds. Such spin-spin interactions show that the dominant concept of the untisymmetric wave function for fermions is inapplicable not only in the simple p-n, p-p, and n-n systems but also in the LS coupling of atoms in which the electrons interact from different quantum states giving either S = 0 or S = l. (author)

  4. The nuclear spectroscopic telescope array (NuSTAR) high-energy X-ray mission

    DEFF Research Database (Denmark)

    Madsen, Kristin K.; Harrison, Fiona A.; Hongjun An

    2014-01-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR) mission was launched on 2012 June 13 and is the first focusing high-energy X-ray telescope in orbit operating above ~10 keV. NuSTAR flies two co-aligned Wolter-I conical approximation X-ray optics, coated with Pt/C and W/Si multilayers...

  5. Nuclear diagnostics of high intensity laser plasma interactions

    International Nuclear Information System (INIS)

    Krushelnick, K.; Santala, M.I.K.; Beg, F.N.; Clark, E.L.; Dangor, A.E.; Tatarakis, M.; Watts, I.; Wei, M.S.; Zepf, M.; Ledingham, K.W.D.; McCanny, T.; Spencer, I.; Clarke, R.J.; Norreys, P.A.

    2002-01-01

    Nuclear activation has been observed in materials exposed to energetic protons and heavy ions generated from high intensity laser-solid interactions (at focused intensities up to 5x10 19 W/cm 2 ). The energy spectrum of the protons is determined through the use of these nuclear activation techniques and is found to be consistent with other ion diagnostics. Heavy ion fusion reactions and large neutron fluxes from the (p, n) reactions were also observed. The reduction of proton emission and increase in heavy ion energy using heated targets was also observed

  6. A short note on physical properties to irradiated nuclear fuel by means of X-ray diffraction and neutron scattering techniques

    Energy Technology Data Exchange (ETDEWEB)

    Abdullah, Yusof, E-mail: yusofabd@nuclearmalaysia.gov.my; Husain, Hishamuddin; Hak, Cik Rohaida Che; Alias, Nor Hayati; Yusof, Mohd Reusmaazran; Kasim, Norasiah Ab; Zali, Nurazila Mat [Malaysian Nuclear Agency, Bangi, Kajang 43000, Selangor (Malaysia); Mohamed, Abdul Aziz [College of Engineering, Universiti Tenaga National, Jalan Ikram-Uniten, 43000 Kajang, Selangor (Malaysia)

    2015-04-29

    For nuclear reactor applications, understanding the evolution of the fuel materials microstructure during irradiation are of great importance. This paper reviews the physical properties of irradiated nuclear fuel analysis which are considered to be of most importance in determining the performance behavior of fuel. X-rays diffraction was recognize as important tool to investigate the phase identification while neutron scattering analyses the interaction between uranium and other materials and also investigation of the defect structure.

  7. Application of γ-ray radiography in non-destructive examination at Daya Day Nuclear Power Plant

    International Nuclear Information System (INIS)

    Zhao Yizhen

    1994-11-01

    The method of γ-ray radiographic examination for NDE of welds in nuclear island erection works is presented. The content includes selection of γ-ray examination equipment, γ-ray source, different methods of γ-ray examination on different parts, comparison of sensitivity of X-ray examination with that of γ-ray examination, advantages and application of γ-ray radiographic examination. (5 figs., 5 tabs.)

  8. The residual proton-neutron interaction and nuclear collectivity

    International Nuclear Information System (INIS)

    Casten, R.F.

    1990-01-01

    The essential role of the valence, residual p-n interaction in the development of collectivity, though long known in general terms, has recently become increasingly apparent. A brief review of the p-n interaction is given, including some very basic nuclear data that illustrate its effects and the phenomenological N p N n scheme and the P-factor. This is followed by a discussion of recent experimental extractions of p-n matrix elements throughout the periodic table and theoretical efforts to understand them, in terms of both Shell and Nilsson models. 20 refs., 13 figs

  9. Interactive nuclear plant analyzer for VVER-440 reactor

    International Nuclear Information System (INIS)

    Shier, W.; Horak, W.; Kennett, R.

    1992-05-01

    This document discusses an interactive nuclear plant analyzer (NPA) which has been developed for a VVER-440, Model 213 reactor for use in the training of plant personnel, the development and verification of plant operating procedures, and in the analysis of various anticipated operational occurrences and accident scenarios. This NPA is operational on an IBM RISC-6000 workstation and utilizes the RELAP5/MOD2 computer code for the calculation of the VVER-440 reactor response to the interactive commands initiated by the NPA operator

  10. Guidance for nuclear medicine staff on radiopharmaceuticals drug interaction

    International Nuclear Information System (INIS)

    Santos-Oliveira, Ralph

    2009-01-01

    Numerous drug interactions related to radiopharmaceuticals take place every day in hospitals many of which are not reported or detected. Information concerning this kind of reaction is not abundant, and nuclear medicine staff are usually overwhelmed by this information. To better understand this type of reaction, and to help nuclear medicine staff deal with it, a review of the literature was conducted. The results show that almost all of radiopharmaceuticals marketed around the world present drug interactions with a large variety of compounds. This suggests that a logical framework to make decisions based on reviews incorporating adverse reactions must be created. The review also showed that researchers undertaking a review of literature, or even a systematic review that incorporates drug interactions, must understand the rationale for the suggested methods and be able to implement them in their review. Additionally, a global effort should be made to report as many cases of drug interaction with radiopharmaceuticals as possible. With this, a complete picture of drug interactions with radiopharmaceuticals can be drawn. (author)

  11. Nuclear quadrupole interactions in ferroelectric compounds of HF181

    International Nuclear Information System (INIS)

    Kunzler, J.V.

    1971-01-01

    Measurements of nuclear quadrupole interaction constants in perovkite-type compounds of PbHfO 3 , SnhfO 3 , CaHfO 3 e SrHfO 3 have been performed using the perturbed angular correlation technique. A range of fundamental frequencies from 150 to 550 Megaradians persecond was determined. The variation of quadrupole constants has been discussed through the molecular orbital theory

  12. Heat transfer and mechanical interactions in fusion nuclear systems

    International Nuclear Information System (INIS)

    Nygren, R.E.

    1984-01-01

    This general review of design issues in heat transfer and mechanical interactions of the first wall, blanket and shield systems of tokamak and mirror fusion reactors begins with a brief introduction to fusion nuclear systems. The design issues are summarized in tables and the following examples are described to illustrate these concerns: the surface heating of limiters, heat transfer from solid breeders, MHD effects in liquid metal blankets, mechanical loads from electromagnetic transients and remote maintenance

  13. On-line nuclear ash gauge for coal based on gamma-ray transmission techniques

    International Nuclear Information System (INIS)

    Rizk, R.A.M.; El-Kateb, A.H.; Abdul-Kader, A.M.

    1999-01-01

    Developments and applications of on-line nuclear gauges in the coal industry are highly requested. A nuclear ash gauge for coal, based on γ-ray transmission techniques is developed. Single and dual energy γ-ray beams are used to determine the ash content of coal. The percentage ash content as a function of the γ-ray intensities transmitted through coal samples is measured and sensitivity curves are obtained. An empirical formulation relating the ash content values to the γ-ray intensities is derived. Preliminary results show that both single and dual energy γ-ray transmission techniques can be used to give a rapid on-line estimation of the ash concentration values in coal with low cost and reasonable accuracy, but the dual one is much preferable. (author)

  14. Advanced Laser-Compton Gamma-Ray Sources for Nuclear Materials Detection, Assay and Imaging

    Science.gov (United States)

    Barty, C. P. J.

    2015-10-01

    Highly-collimated, polarized, mono-energetic beams of tunable gamma-rays may be created via the optimized Compton scattering of pulsed lasers off of ultra-bright, relativistic electron beams. Above 2 MeV, the peak brilliance of such sources can exceed that of the world's largest synchrotrons by more than 15 orders of magnitude and can enable for the first time the efficient pursuit of nuclear science and applications with photon beams, i.e. Nuclear Photonics. Potential applications are numerous and include isotope-specific nuclear materials management, element-specific medical radiography and radiology, non-destructive, isotope-specific, material assay and imaging, precision spectroscopy of nuclear resonances and photon-induced fission. This review covers activities at the Lawrence Livermore National Laboratory related to the design and optimization of mono-energetic, laser-Compton gamma-ray systems and introduces isotope-specific nuclear materials detection and assay applications enabled by them.

  15. Photon interaction studies using 241Am γ-rays

    Indian Academy of Sciences (India)

    rays from a 241Am source. These include attenuation studies as well as photoelectric absorption studies in various samples. The attenuation studies have been made using leaf and wood samples, samples like sand, sugar etc., which ...

  16. Role amplification of the coulomb interaction in nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Ashok; Soni, S K; Pancholi, S K; Gupta, S L [AN SSSR, Moscow. Radiotekhnicheskij Inst.

    1976-10-01

    The genarally adopted estimate of coulomb interaction in nuclear reactions based on the comparison of relative energies of real particles participating in the reaction with the coulomb barrier has been shown to provide wrong presentation of the role of coulomb interaction in the reaction mechanism. The relative energy of particles participating in virtual processes forming the reaction mechanism and its relation to the coulomb barrier turn out to be tens of per cent less than for the particles in an inlet channel. This is the main reason of increasing the role of coulomb interaction in the reaction mechanism. This increase is particularly significant for nuclei with large charges, in particular, in heavy ion reaction.

  17. Hyperon interaction in free space and nuclear matter

    Energy Technology Data Exchange (ETDEWEB)

    Dhar, Madhumita; Lenske, Horst [Institute for Theoretical Physics, Justus- Liebig-University Giessen (Germany)

    2015-07-01

    Baryon-baryon interactions within the SU(3)-octet are investigated in free space and nuclear matter.A meson exchange model based on SU(3) symmetry is used for determining the interaction. The Bethe-Salpeter equations are solved in a 3-D reduction scheme. In-medium effect has been incorporated by including a two particle Pauli projector operator in the scattering equation. The coupling of the various channels of total strangeness S and conserved total charge is studied in detail. Special attention is paid to the physical thresholds. The density dependence of interaction is clearly seen in the variation of the in-medium low-energy parameters. The approach is compared to descriptions derived from chiral-EFT and other meson-exchange models e.g. the Nijmegen and the Juelich model.

  18. Hyperon interaction in free space and nuclear matter

    Energy Technology Data Exchange (ETDEWEB)

    Dhar, Madhumita [Justus-Liebig University Giessen (Germany); Lenske, Horst [Justus-Liebig University Giessen (Germany); GSI, Darmstadt (Germany)

    2016-07-01

    A new approach to the SU(3) flavour symmetric meson-exchange model is introduced to describe free space baryon-baryon interaction. The Bethe-Salpeter equations are solved in a 3-D reduction scheme. The coupling of the various channels of total strangeness S and conserved total charge Q is studied in detail. Special attention is paid to the physical thresholds. The derived vacuum interaction has then been used to derive nuclear medium effect by employing the Pauli projector operator in 3-D reduced Bethe-Salpeter equation. The in-medium properties of the interaction are clearly seen in the variation of the in-medium low-energy parameters as a function of density.

  19. Interactive nuclear plant analyzer for the VVER-440 reactor

    International Nuclear Information System (INIS)

    Shier, W.; Kennett, R.

    1993-01-01

    An interactive nuclear plant analyzer (NPA) has been developed for a VVER-440 model 213 reactor for use in the training of plant personnel, the development and verification of plant operating procedures, and in the analysis of various anticipated operational occurrences and accident scenarios. This NPA is operational on an IBM RISC-6000 workstation and utilizes the RELAP5/MOD2 computer code for the calculation of the VVER-440 reactor response to the interactive commands initiated by the NPA operator. Results of the interactive calculation can be through the user-defined, digital display of various plant parameters and through color changes that reflect changes in primary system fluid temperatures, fuel and clad temperatures, and the temperatures of other metal structures. In addition, changes in the status of various components and system can be initiated and/or displayed both numerically and graphically on the mask

  20. DEPENDENCE OF X-RAY BURST MODELS ON NUCLEAR REACTION RATES

    Energy Technology Data Exchange (ETDEWEB)

    Cyburt, R. H.; Keek, L.; Schatz, H. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Amthor, A. M. [Department of Physics and Astronomy, Bucknell University, Lewisburg, PA 17837 (United States); Heger, A.; Meisel, Z.; Smith, K. [Joint Institute for Nuclear Astrophysics (JINA), Michigan State University, East Lansing, MI 48824 (United States); Johnson, E. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)

    2016-10-20

    X-ray bursts are thermonuclear flashes on the surface of accreting neutron stars, and reliable burst models are needed to interpret observations in terms of properties of the neutron star and the binary system. We investigate the dependence of X-ray burst models on uncertainties in (p, γ ), ( α , γ ), and ( α , p) nuclear reaction rates using fully self-consistent burst models that account for the feedbacks between changes in nuclear energy generation and changes in astrophysical conditions. A two-step approach first identified sensitive nuclear reaction rates in a single-zone model with ignition conditions chosen to match calculations with a state-of-the-art 1D multi-zone model based on the Kepler stellar evolution code. All relevant reaction rates on neutron-deficient isotopes up to mass 106 were individually varied by a factor of 100 up and down. Calculations of the 84 changes in reaction rate with the highest impact were then repeated in the 1D multi-zone model. We find a number of uncertain reaction rates that affect predictions of light curves and burst ashes significantly. The results provide insights into the nuclear processes that shape observables from X-ray bursts, and guidance for future nuclear physics work to reduce nuclear uncertainties in X-ray burst models.

  1. Horizontal cosmic ray muon radiography for imaging nuclear threats

    International Nuclear Information System (INIS)

    Morris, Christopher L.; Bacon, Jeffrey; Borozdin, Konstantin; Fabritius, Joseph; Miyadera, Haruo; Perry, John; Sugita, Tsukasa

    2014-01-01

    Muon tomography is a technique that uses information contained in the Coulomb scattering of cosmic ray muons to generate three dimension images of volumes between tracking detectors. Advantages of this technique are the muons ability to penetrate significant overburden and the absence of any additional dose beyond the natural cosmic ray flux. Disadvantages include the long exposure times and limited resolution because of the low flux. Here we compare the times needed to image objects using both vertically and horizontally mounted tracking detectors and we develop a predictive model for other geometries

  2. Horizontal cosmic ray muon radiography for imaging nuclear threats

    Science.gov (United States)

    Morris, Christopher L.; Bacon, Jeffrey; Borozdin, Konstantin; Fabritius, Joseph; Miyadera, Haruo; Perry, John; Sugita, Tsukasa

    2014-07-01

    Muon tomography is a technique that uses information contained in the Coulomb scattering of cosmic ray muons to generate three dimension images of volumes between tracking detectors. Advantages of this technique are the muons ability to penetrate significant overburden and the absence of any additional dose beyond the natural cosmic ray flux. Disadvantages include the long exposure times and limited resolution because of the low flux. Here we compare the times needed to image objects using both vertically and horizontally mounted tracking detectors and we develop a predictive model for other geometries.

  3. Nuclear quadrupole interaction measurements of 19F* and 22Na* on Graphite

    International Nuclear Information System (INIS)

    Djoko-Surono, Th; Martin, Peter W

    1996-01-01

    Time differential perturbed angular distribution (TDPAD) technique has been used to investigate nuclear quadrupole interactions of 19 F * and 22 Na * in graphite. We concentrated the measurements on pseudo single crystal graphite called Highly Oriented Pyrolytic Graphite for it has an ordered structure in which the c-axes of the microcrystals aligned in a certain direction with the mosaic spread less than 1 o , while the a- and b-axes randomly oriented on a plane perpendicular to the c-axes. Interactions between quadrupole moment of 19 F * and 22 Na * with its surroundings electric field gradient were studied by detecting the γ-rays distribution, W(Θ,t). For 1 9F * we found one static interaction. The corresponding electric field gradient was V zz =3.24(19)x10 22 V/m 2 . In the case of 22 Na * we found no evidence of nuclear quadrupole interaction, however, we were able to conclude that |QV 22 | 19 bV/m 2 . Using theoretical calculation Q=0.06 barn, we find that |V zz | 20 V/m 2 . These results indicate that the value efg depend on two factors, the host crystal and the core electrons. The core electrons contribution to the total efg is considerably large

  4. A Prototype Scintillating-Fibre Tracker for the Cosmic-ray Muon Tomography of Legacy Nuclear Waste Containers

    Science.gov (United States)

    Kaiser, R.; Clarkson, A.; Hamilton, D. J.; Hoek, M.; Ireland, D. G.; Johnston, J. R.; Keri, T.; Lumsden, S.; Mahon, D. F.; McKinnon, B.; Murray, M.; Nutbeam-Tuffs, S.; Shearer, C.; Staines, C.; Yang, G.; Zimmerman, C.

    2014-03-01

    Cosmic-ray muons are highly-penetrative charged particles observed at sea level with a flux of approximately 1 cm-2 min-1. They interact with matter primarily through Coulomb scattering which can be exploited in muon tomography to image objects within industrial nuclear waste containers. This paper presents the prototype scintillating-fibre detector developed for this application at the University of Glasgow. Experimental results taken with test objects are shown in comparison to results from GEANT4 simulations. These results verify the simulation and show discrimination between the low, medium and high-Z materials imaged.

  5. High-resolution γ-ray spectroscopy: a versatile tool for nuclear β-decay studies at TRIUMF-ISAC

    Science.gov (United States)

    Ball, G. C.; Achtzehn, T.; Albers, D.; Khalili, J. S. Al; Andreoiu, C.; Andreyev, A.; Ashley, S. F.; Austin, R. A. E.; Becker, J. A.; Bricault, P.; Chan, S.; Chakrawarthy, R. S.; Churchman, R.; Coombes, H.; Cunningham, E. S.; Daoud, J.; Dombsky, M.; Drake, T. E.; Eshpeter, B.; Finlay, P.; Garrett, P. E.; Geppert, C.; Grinyer, G. F.; Hackman, G.; Hanemaayer, V.; Hyland, B.; Jones, G. A.; Koopmans, K. A.; Kulp, W. D.; Lassen, J.; Lavoie, J. P.; Leslie, J. R.; Litvinov, Y.; Macdonald, J. A.; Mattoon, C.; Melconian, D.; Morton, A. C.; Osborne, C. J.; Pearson, C. J.; Pearson, M.; Phillips, A. A.; Ressler, J. J.; Sarazin, F.; Schumaker, M. A.; Schwarzenberg, J.; Scraggs, H. C.; Smith, M. B.; Svensson, C. E.; Valiente-Dobon, J. J.; Waddington, J. C.; Walker, P. M.; Wendt, K.; Williams, S. J.; Wood, J. L.; Zganjar, E. F.

    2005-10-01

    High-resolution γ-ray spectroscopy is essential to fully exploit the unique, high-quality beams available at the next generation of radioactive ion beam facilities such as the TRIUMF isotope separator and accelerator (ISAC). The 8π spectrometer, which consists of 20 Compton-suppressed HPGe detectors, has recently been reconfigured for a vigorous research programme in weak interaction and nuclear structure physics. With the addition of a variety of ancillary detectors it has become the world's most powerful device dedicated to β-decay studies. This paper provides a brief overview of the apparatus and highlights from recent experiments.

  6. A Prototype Scintillating-Fibre Tracker for the Cosmic-ray Muon Tomography of Legacy Nuclear Waste Containers

    Directory of Open Access Journals (Sweden)

    Kaiser R.

    2014-03-01

    Full Text Available Cosmic-ray muons are highly-penetrative charged particles observed at sea level with a flux of approximately 1 cm−2 min−1. They interact with matter primarily through Coulomb scattering which can be exploited in muon tomography to image objects within industrial nuclear waste containers. This paper presents the prototype scintillating-fibre detector developed for this application at the University of Glasgow. Experimental results taken with test objects are shown in comparison to results from GEANT4 simulations. These results verify the simulation and show discrimination between the low, medium and high-Z materials imaged.

  7. Skyrme interaction to second order in nuclear matter

    Science.gov (United States)

    Kaiser, N.

    2015-09-01

    Based on the phenomenological Skyrme interaction various density-dependent nuclear matter quantities are calculated up to second order in many-body perturbation theory. The spin-orbit term as well as two tensor terms contribute at second order to the energy per particle. The simultaneous calculation of the isotropic Fermi-liquid parameters provides a rigorous check through the validity of the Landau relations. It is found that published results for these second order contributions are incorrect in most cases. In particular, interference terms between s-wave and p-wave components of the interaction can contribute only to (isospin or spin) asymmetry energies. Even with nine adjustable parameters, one does not obtain a good description of the empirical nuclear matter saturation curve in the low density region 0\\lt ρ \\lt 2{ρ }0. The reason for this feature is the too strong density-dependence {ρ }8/3 of several second-order contributions. The inclusion of the density-dependent term \\frac{1}{6}{t}3{ρ }1/6 is therefore indispensable for a realistic description of nuclear matter in the Skyrme framework.

  8. Visualization of magnetic dipolar interaction based on scanning transmission X-ray microscopy

    International Nuclear Information System (INIS)

    Ohtori, Hiroyuki; Iwano, Kaoru; Takeichi, Yasuo; Ono, Kanta; Mitsumata, Chiharu; Yano, Masao; Kato, Akira; Miyamoto, Noritaka; Shoji, Tetsuya; Manabe, Akira

    2014-01-01

    Using scanning transmission X-ray microscopy (STXM), in this report we visualized the magnetic dipolar interactions in nanocrystalline Nd-Fe-B magnets and imaged their magnetization distributions at various applied fields. We calculated the magnetic dipolar interaction by analyzing the interaction between the magnetization at each point and those at the other points on the STXM image.

  9. Nuclear Structure Studies with Gamma-Ray Beams

    Directory of Open Access Journals (Sweden)

    Tonchev Anton

    2015-01-01

    Full Text Available In stable and weakly bound neutron-rich nuclei, a resonance-like concentration of dipole states has been observed for excitation energies below the neutron-separation energy. This clustering of strong dipole states has been named the Pygmy Dipole Resonance (PDR in contrast to the Giant Dipole Resonance (GDR that dominates the E1 response. Understanding the PDR is presently of great interest in nuclear structure and nuclear astrophysics. High-sensitivity studies of E1 and M1 transitions in closed-shell nuclei using monoenergetic and 100% linearly-polarized photon beams are presented.

  10. Nuclear Structure Studies with Gamma-Ray Beams

    Science.gov (United States)

    Tonchev, Anton; Bhatia, Chitra; Kelley, John; Raut, Rajarshi; Rusev, Gencho; Tornow, Werner; Tsoneva, Nadia

    2015-05-01

    In stable and weakly bound neutron-rich nuclei, a resonance-like concentration of dipole states has been observed for excitation energies below the neutron-separation energy. This clustering of strong dipole states has been named the Pygmy Dipole Resonance (PDR) in contrast to the Giant Dipole Resonance (GDR) that dominates the E1 response. Understanding the PDR is presently of great interest in nuclear structure and nuclear astrophysics. High-sensitivity studies of E1 and M1 transitions in closed-shell nuclei using monoenergetic and 100% linearly-polarized photon beams are presented.

  11. Nuclear γ-ray spectroscopy of cool free atoms

    International Nuclear Information System (INIS)

    Rivlin, Lev A

    1999-01-01

    Consideration is given to the capabilities of gamma-ray spectroscopy of the nuclei of free neutral atoms cooled employing modern laser light-pressure techniques. This spectroscopy is comparable with the Mossbauer spectroscopy in respect of the expected resolving power. (laser applications and other topics in quantum electronics)

  12. Guidance for nuclear medicine staff on radiopharmaceuticals drug interaction

    Directory of Open Access Journals (Sweden)

    Ralph Santos-Oliveira

    2009-12-01

    Full Text Available Numerous drug interactions related to radiopharmaceuticals take place every day in hospitals many of which are not reported or detected. Information concerning this kind of reaction is not abundant, and nuclear medicine staff are usually overwhelmed by this information. To better understand this type of reaction, and to help nuclear medicine staff deal with it, a review of the literature was conducted. The results show that almost all of radiopharmaceuticals marketed around the world present drug interactions with a large variety of compounds. This suggests that a logical framework to make decisions based on reviews incorporating adverse reactions must be created. The review also showed that researchers undertaking a review of literature, or even a systematic review that incorporates drug interactions, must understand the rationale for the suggested methods and be able to implement them in their review. Additionally, a global effort should be made to report as many cases of drug interaction with radiopharmaceuticals as possible. With this, a complete picture of drug interactions with radiopharmaceuticals can be drawn.Diversos casos de interações medicamentosas com radiofármacos ocorrem diariamente na rotina hospitalar, contudo muitos deles não são notificados ou mesmo percebidos. Informações a respeito desse tipo de reação não é abundante e os profissionais da medicina nuclear muitas vezes estão assoberbados por essas informações. De modo a entender esse tipo de reação e auxiliar a medicina nuclear a lidar com essa situação uma revisão da literatura foi realizada. Os resultados mostraram que a totalidade dos radiofármacos comercializados no mundo apresentam interação medicamentosa com uma enorme variedade de outros medicamentos. Dessa forma sugere-se que revisões sobre radiofármacos inclua um capítulo sobre efeitos adversos. Além disso, um esforço mundial para notificar efeitos adversos deve ser realizado, pois somente

  13. Effects of Gogny type interactions on the nuclear flow

    International Nuclear Information System (INIS)

    Sebille, F.; De La Mota, V.; Jouault, B.; Schuck, P.

    1995-01-01

    A flow analysis on symmetric and asymmetric reactions from 100 to 400 MeV/n is performed in the framework of the semi-classical Landau-Vlasov approach. In this energy range our results present two different trends. At lower energies it is governed by the momentum dependence of the nuclear optical potential, whereas at higher energies its density dependence plays a crucial role leading to a rather pronounced sensitivity of the incompressibility modulus. The non-locality of the nuclear interaction is relevant for asymmetric colliding systems. With an incompressibility modulus in the vicinity of 200 MeV, an excellent quantitative description of the flow behavior with incident energy and impact parameter or the system mass is provided. (authors)., 26 refs., 6 figs., 3 tabs

  14. X-ray spectromicroscopy studies of protein-polymer Interactions

    International Nuclear Information System (INIS)

    Hitchcock, A.P.; Tyliszczak, T.; Heng, Y.M.; Cornelius, R.; Brash, J.L.; Ade, H.; Anders, S.; Scholl, A.; Nolting, F.

    2000-01-01

    Identification of the sites of protein binding on laterally heterogeneous polymer surfaces can help understand mechanisms of bio-passivation, which in turn has practical impact on developing improved polymers for medical uses, such as blood contact applications. We have used scanning X-ray transmission microscopy and photoelectron emission microscopy to explore the sensitivity of these X-ray microscopies to detection of human serum albumin adsorbed onto the surface of two different polyurethane polymers. Both techniques appear capable of the requisite monolayer sensitivity

  15. Image processing techniques for thermal, x-rays and nuclear radiations

    International Nuclear Information System (INIS)

    Chadda, V.K.

    1998-01-01

    The paper describes image acquisition techniques for the non-visible range of electromagnetic spectrum especially thermal, x-rays and nuclear radiations. Thermal imaging systems are valuable tools used for applications ranging from PCB inspection, hot spot studies, fire identification, satellite imaging to defense applications. Penetrating radiations like x-rays and gamma rays are used in NDT, baggage inspection, CAT scan, cardiology, radiography, nuclear medicine etc. Neutron radiography compliments conventional x-rays and gamma radiography. For these applications, image processing and computed tomography are employed for 2-D and 3-D image interpretation respectively. The paper also covers main features of image processing systems for quantitative evaluation of gray level and binary images. (author)

  16. Experimental nuclear level densities and γ-ray strength functions in Sc and V isotopes

    International Nuclear Information System (INIS)

    Larsen, A. C.; Guttormsen, M.; Ingebretsen, F.; Messelt, S.; Rekstad, J.; Siem, S.; Syed, N. U. H.; Chankova, R.; Loennroth, T.; Schiller, A.; Voinov, A.

    2008-01-01

    The nuclear physics group at the Oslo Cyclotron Laboratory has developed a method to extract nuclear level density and γ-ray strength function from first-generation γ-ray spectra. This method is applied on the nuclei 44,45 Sc and 50,51 V in this work. The experimental level densities of 44,45 Sc are compared to calculated level densities using a microscopic model based on BCS quasiparticles within the Nilsson level scheme. The γ-ray strength functions are also compared to theoretical expectations, showing an unexpected enhancement of the γ-ray strength for low γ energies (E γ ≤3 MeV) in all the isotopes studied here. The physical origin of this enhancement is not yet understood

  17. Role of pn-pairs interaction in nuclear structure

    International Nuclear Information System (INIS)

    Nie, G.K.

    2004-01-01

    Full text: The nuclear structure approach is based on theory of interaction of pn-pairs with suggestion that proton and neutron of one pair have the same nuclear potential. In frame of this model nuclei with N=Z were analyzed in [1,2]. In [1] radii of position of last proton were estimated on difference of proton and neutron separation energies. In [2] a phenomenological formula for calculation of binding energy of alpha- cluster nuclei was found. Present work is devoted to developing the nuclear structure model. Coulomb energy of nuclei with N=Z has been found from sum of differences of separation energies of protons and neutrons belonging to one pairs. From analysis of nuclei 12 C and 16 O the value of energy of Coulomb repulsion between 2 α -clusters has been estimated equal to ε C α =1.925 MeV [3], which means that value of nuclear (meson) interaction between 2 α -clusters is expected to be ε m αα = ε cov αα + ε C α =4.350 MeV. From suggestion that energy of long range Coulomb repulsion is compensated by surface tension energy an equation has been found to calculate radius of position of last proton on value of Z. Charge radii of nuclei from 58 Ni to 208 Bi and further have been calculated with difference from experimental ones in several hundredths of fm. In the approach binding energy of excess neutrons stays beyond the consideration. Therefore, in calculation of binding energies of nuclei the experimental values of separation energies of excess neutrons are used. There is a good agreement between calculated values of binding energies of some isotopes of all known elements as well as separation energies of alpha particle and deuteron and experimental data. The difference from experimental binding energy in most of the cases is about 0.5% and less

  18. Study on gamma-ray transitions induced in nuclear spin isomers by X-rays

    International Nuclear Information System (INIS)

    Yang Tianli; Hao Fanhua; Liu Xiaoya; Gong Jian

    2005-10-01

    The development of induced X-ray has been summarized for high spin isomer. the radiation model, transition mechanism and experiment plan have been introduced. The experiments about isomers 180m Ta and 178m2 Hf have been narrated in detail respectively, and the analysis between those results have been obtained. The reasonable theoretical frame and good experimental data have offered the powerful technique base for pumping γ-ray laser with low energy. (authors)

  19. Structure-soil-structure interaction of nuclear structures

    International Nuclear Information System (INIS)

    Snyder, M.D.; Shaw, D.E.; Hall, J.R. Jr.

    1975-01-01

    Structure-to-structure interaction resulting from coupling of the foundations through the soil has traditionally been neglected in the seismic analysis of nuclear power plants. This paper examines the phenomenon and available methods of analytical treatment, including finite element and lumped parameter methods. Finite element techniques have lead to the treatment of through soil coupling of structural foundations using two dimensional plane strain models owing to the difficulty of considering three dimensional finite element models. The coupling problem is treated by means of a lumped parameter model derived from elastic half-space considerations. Consequently, the method is applicable to the interaction of any number of foundations and allows the simultaneous application of tri-directional excitation. The method entails the idealization of interacting structures as lumped mass/shear beams with lumped soil springs and dampers beneath each foundation plus a coupling matrix between the interacting foundations. Utilizing classical elastic half-space methods, the individual foundation soil springs and dampers may be derived, accounting for the effects of embedment and soil layering, analogous to the methods used for single soil-structure, interaction problems. The coupling matrix is derived by generating influence coefficients based on the geometric relationship of the structures using classical half-space solutions. The influence coefficients form the coupling flexibility matrix which is inverted to yield the coupling matrix for the lumped parameter model

  20. Time-reversal-noninvariant, parity-conserving nuclear interactions

    International Nuclear Information System (INIS)

    Haxton, W.C.; Hoering, A.; Washington Univ., Seattle, WA; Melbourne Univ., Parkville, VIC

    1993-01-01

    In this paper the authors quantify the relationship between compound nucleus (CN) and electric dipole moment (edm) constraints on long-ranged time-reversal-noninvariant (TRNI), parity-conserving (PC) interactions. It begins by reviewing the work that has been done in compound nuclei. In the second section, it considers the general form of the TRNI PC interaction in meson exchange models. In the third section discusses one mechanism for generating an atomic edm, a TRNI PC nuclear interaction mediate by ρ exchange coupled with Z exchange between atomic electrons and the nucleus. While a variety of other mechanisms can similarly generate edms from TRNI PC interactions this example has some interesting experimental consequences. The limits extracted are then translated into a constraint on α, the ratio of typical TRNI and TRI N N matrix elements. It is concluded that such atomic edm limits on TRNI PC interactions are at least comparable to those obtained in the best CN studies. These limits from long-distance contributions to edms are then compared to the stringent bounds obtained recently by Conti and Khriplovich from studies of short-ranged mechanisms. 37 refs., 2 figs

  1. Nuclear and x-ray spectroscopy with radioactive sources. Fifteenth annual progress report

    International Nuclear Information System (INIS)

    Rink, R.W.; Wood, J.L.

    1979-01-01

    Research during the year is summarized briefly for the following areas: nuclear spectroscopy (including nuclear systematics and models and experimental studies of heavy-nucleus decays), x rays from radioactive sources (including L-subshell x-ray fluorescence and Coster-Kronig yields and the measurement of tailing corrections in low-energy coincidence intensity determinations), and miscellaneous topics concerning computer codes and equipment. One may assume publication of completed work in the usual channels. Lists of personnel, publications, etc., are included. 7 figures

  2. Nuclear Enhanced X-ray Maximum Entropy Method Used to Analyze Local Distortions in Simple Structures

    DEFF Research Database (Denmark)

    Christensen, Sebastian; Bindzus, Niels; Christensen, Mogens

    We introduce a novel method for reconstructing pseudo nuclear density distributions (NDDs): Nuclear Enhanced X-ray Maximum Entropy Method (NEXMEM). NEXMEM offers an alternative route to experimental NDDs, exploiting the superior quality of synchrotron X-ray data compared to neutron data. The method...... proposed to result from anharmonic phonon scattering or from local fluctuating dipoles on the Pb site.[1,2] No macroscopic symmetry change are associated with these effects, rendering them invisible to conventional crystallographic techniques. For this reason PbX was until recently believed to adopt...

  3. Nuclear hyperfine interactions and chemical bonding in high TC superconductors

    International Nuclear Information System (INIS)

    Danon, J.

    1987-01-01

    Nuclear quadrupole resonances of Cu 63 and Fe 57 Moessbauer spectroscopy of the high temperature superconductor YBa 2 Cu 3 O 7-γ e described together with synchrotron radiation studies of the copper oxidation states in this material. The Moessbauer spectra of 57 Fe in the two distinct crystallographic sites of the Cu atoms in YBa 2 Cu 3 O 7-γ are very similar from the quadrupole coupling point of view although exhibiting markedly different values for the isomer shift. The role of oxygen vacancies in the hyperfine interactions is discussed. (author) [pt

  4. Nuclear Fusion Research Understanding Plasma-Surface Interactions

    CERN Document Server

    Clark, Robert E.H

    2005-01-01

    It became clear in the early days of fusion research that the effects of the containment vessel (erosion of "impurities") degrade the overall fusion plasma performance. Progress in controlled nuclear fusion research over the last decade has led to magnetically confined plasmas that, in turn, are sufficiently powerful to damage the vessel structures over its lifetime. This book reviews current understanding and concepts to deal with this remaining critical design issue for fusion reactors. It reviews both progress and open questions, largely in terms of available and sought-after plasma-surface interaction data and atomic/molecular data related to these "plasma edge" issues.

  5. Bending-Twisting Motions and Main Interactions in Nucleoplasmin Nuclear Import.

    Directory of Open Access Journals (Sweden)

    Marcos Tadeu Geraldo

    Full Text Available Alpha solenoid proteins play a key role in regulating the classical nuclear import pathway, recognizing a target protein and transporting it into the nucleus. Importin-α (Impα is the solenoid responsible for cargo protein recognition, and it has been extensively studied by X-ray crystallography to understand the binding specificity. To comprehend the main motions of Impα and to extend the information about the critical interactions during carrier-cargo recognition, we surveyed different conformational states based on molecular dynamics (MD and normal mode (NM analyses. Our model of study was a crystallographic structure of Impα complexed with the classical nuclear localization sequence (cNLS from nucleoplasmin (Npl, which was submitted to multiple 100 ns of MD simulations. Representative conformations were selected for calculating the 87 lowest frequencies NMs of vibration, and a displacement approach was applied along each NM. Based on geometric criteria, using the radius of curvature and inter-repeat angles as the reference metrics, the main motions of Impα were described. Moreover, we determined the salt bridges, hydrogen bonds and hydrophobic interactions in the Impα-NplNLS interface. Our results show the bending and twisting motions participating in the recognition of nuclear proteins, allowing the accommodation and adjustment of a classical bipartite NLS sequence. The essential contacts for the nuclear import were also described and were mostly in agreement with previous studies, suggesting that the residues in the cNLS linker region establish important contacts with Impα adjusting the cNLS backbone. The MD simulations combined with NM analysis can be applied to the Impα-NLS system to help understand interactions between Impα and cNLSs and the analysis of non-classic NLSs.

  6. Study of the Λ(1116 interaction in cold nuclear matter

    Directory of Open Access Journals (Sweden)

    Arnold Oliver

    2014-03-01

    Full Text Available The interaction of Λ hyperons with baryonic nuclear matter at saturation density is expected to be attractive. The interaction strength was extracted from hypernuclei data. A different approach to obtain the potential depth of the Λ mean-field potential is to compare experimental data with transport simulations. We analyze experimental data of Λ hyperons measured with the HADES detector in p+93Nb reactions with a kinetic beam energy of 3.5 GeV carried by the proton. The high statistic of measured Λ hyperons allows us to perform a double differential analysis in Lorentz-invariant observables of transverse momentum and rapidity. We present the analysis method and a comparison with simulations.

  7. Theory of nuclear quadrupole interactions in solid hydrogen fluoride

    International Nuclear Information System (INIS)

    Mohamed, N.S.; Sahoo, N.; Das, T.P.; Kelires, P.C.

    1990-01-01

    The nuclear quadrupole interaction of 19 F * (I=5/2) nucleus in solid hydrogen fluoride has been studied using the Hartree Fock cluster technique to understand the influence of both intrachain hydrogen bonding effects and the weak interchain interaction. On the basis of our investigations, the 34.04 MHz coupling constant observed by TDPAD measurements has been ascribed to the bulk solid while the observed 40.13 MHz coupling constant is suggested as arising from a small two- or three-molecule cluster produced during the proton irradiation process. Two alternate explanations are offered for the origin of coupling constants close to 40 MHz in a number of solid hydrocarbons containing hydrogen and fluorine ligands. (orig.)

  8. Alternate nuclear waste forms and interactions in geologic media

    International Nuclear Information System (INIS)

    Boatner, L.A.; Battle, G.C. Jr.

    1981-04-01

    The primary purposes of the conference on Alternate Nuclear Waste Forms and Interactions in Geologic Media were: First, to provide an opportunity for a review of the status of the research on some of the candidate alternative waste forms; second, to provide an opportunity for comparing the characteristics of alternate waste forms to those of glasses; and third, to stimulate increased interactions between those research groups that were engaged in a more basic approach to characterizing waste forms and those who were concerned with more applied aspects such as the processing of these materials. The motivating philosophy behind this third purpose of the conference was based on the idea that by operating from the soundest possible fundamental base for any of the candidate waste forms, hopefully any future unpleasant surprise - such as that alluded to earlier in the case of glass waste forms - could be avoided. Separate abstracts have been prepared for individual papers for inclusion in the Energy Data Base

  9. Effective pion--nucleon interaction in nuclear matter

    International Nuclear Information System (INIS)

    Celenza, L.S.; Liu, L.C.; Nutt, W.; Shakin, C.M.

    1976-01-01

    We discuss the modification of the interaction between a pion and a nucleon in the presence of an infinite medium of nucleons (nuclear matter). The theory presented here is covariant and is relevant to the calculation of the pion--nucleus optical potential. The specific effects considered are the modifications of the nucleon propagator due to the Pauli principle and the modification of the pion and nucleon propagators due to collisions with nucleons of the medium. We also discuss in detail the pion self-energy in the medium, paying close attention to off-shell effects. These latter effects are particularly important because of the rapid variation with energy of the fundamental pion--nucleon interaction. Numerical results are presented, the main feature being the appearance of a significant damping width for the (3, 3) resonance

  10. The Highest Resolution Chandra View of Photoionization and Jet-Cloud Interaction in the Nuclear Region of NGC 4151

    Science.gov (United States)

    Wang, Junfeng; Fabbiano, G.; Karovska, M.; Elvis, M.; Risaliti, G.; Zezas, A.; Mundell, C. G.

    2009-10-01

    We report high resolution imaging of the nucleus of the Seyfert 1 galaxy NGC 4151 obtained with a 50 ks Chandra High Resolution Camera (HRC) observation. The HRC image resolves the emission on spatial scales of 0farcs5, ~30 pc, showing an extended X-ray morphology overall consistent with the narrow-line region (NLR) seen in optical line emission. Removal of the bright point-like nuclear source and image deconvolution techniques both reveal X-ray enhancements that closely match the substructures seen in the Hubble Space Telescope [O III] image and prominent knots in the radio jet. We find that most of the NLR clouds in NGC 4151 have [O III]/soft X-ray ratio ~10, despite the distance of the clouds from the nucleus. This ratio is consistent with the values observed in NLRs of some Seyfert 2 galaxies, which indicates a uniform ionization parameter even at large radii and a density decreasing as r -2 as expected for a nuclear wind scenario. The [O III]/X-ray ratios at the location of radio knots show an excess of X-ray emission, suggesting shock heating in addition to photoionization. We examine various mechanisms for the X-ray emission and find that, in contrast to jet-related X-ray emission in more powerful active galactic nucleus, the observed jet parameters in NGC 4151 are inconsistent with synchrotron emission, synchrotron self-Compton, inverse Compton of cosmic microwave background photons or galaxy optical light. Instead, our results favor thermal emission from the interaction between radio outflow and NLR gas clouds as the origin for the X-ray emission associated with the jet. This supports previous claims that frequent jet-interstellar medium interaction may explain why jets in Seyfert galaxies appear small, slow, and thermally dominated, distinct from those kpc-scale jets in the radio galaxies.

  11. THE HIGHEST RESOLUTION CHANDRA VIEW OF PHOTOIONIZATION AND JET-CLOUD INTERACTION IN THE NUCLEAR REGION OF NGC 4151

    International Nuclear Information System (INIS)

    Wang Junfeng; Fabbiano, G.; Karovska, M.; Elvis, M.; Risaliti, G.; Zezas, A.; Mundell, C. G.

    2009-01-01

    We report high resolution imaging of the nucleus of the Seyfert 1 galaxy NGC 4151 obtained with a 50 ks Chandra High Resolution Camera (HRC) observation. The HRC image resolves the emission on spatial scales of 0.''5, ∼30 pc, showing an extended X-ray morphology overall consistent with the narrow-line region (NLR) seen in optical line emission. Removal of the bright point-like nuclear source and image deconvolution techniques both reveal X-ray enhancements that closely match the substructures seen in the Hubble Space Telescope [O III] image and prominent knots in the radio jet. We find that most of the NLR clouds in NGC 4151 have [O III]/soft X-ray ratio ∼10, despite the distance of the clouds from the nucleus. This ratio is consistent with the values observed in NLRs of some Seyfert 2 galaxies, which indicates a uniform ionization parameter even at large radii and a density decreasing as r -2 as expected for a nuclear wind scenario. The [O III]/X-ray ratios at the location of radio knots show an excess of X-ray emission, suggesting shock heating in addition to photoionization. We examine various mechanisms for the X-ray emission and find that, in contrast to jet-related X-ray emission in more powerful active galactic nucleus, the observed jet parameters in NGC 4151 are inconsistent with synchrotron emission, synchrotron self-Compton, inverse Compton of cosmic microwave background photons or galaxy optical light. Instead, our results favor thermal emission from the interaction between radio outflow and NLR gas clouds as the origin for the X-ray emission associated with the jet. This supports previous claims that frequent jet-interstellar medium interaction may explain why jets in Seyfert galaxies appear small, slow, and thermally dominated, distinct from those kpc-scale jets in the radio galaxies.

  12. THIEF: An interactive simulation of nuclear materials safeguards

    Energy Technology Data Exchange (ETDEWEB)

    Stanbro, W. D.

    1990-01-01

    The safeguards community is facing an era in which it will be called upon to tighten protection of nuclear material. At the same time, it is probable that safeguards will face more competition for available resources from other activities such as environmental cleanup. To exist in this era, it will be necessary to understand and coordinate all aspects of the safeguards system. Because of the complexity of the interactions involved, this process puts a severe burden on designers and operators of safeguards systems. This paper presents a simulation tool developed at the Los Alamos National Laboratory to allow users to examine the interactions among safeguards elements as they apply to combating the insider threat. The tool consists of a microcomputer-based simulation in which the user takes the role of the insider trying to remove nuclear material from a facility. The safeguards system is run by the computer and consists of both physical protection and MC A computer elements. All data elements describing a scenario can be altered by the user. The program can aid in training, as well as in developing threat scenarios. 4 refs.

  13. Gamma-ray imaging system for real-time measurements in nuclear waste characterisation

    Science.gov (United States)

    Caballero, L.; Albiol Colomer, F.; Corbi Bellot, A.; Domingo-Pardo, C.; Leganés Nieto, J. L.; Agramunt Ros, J.; Contreras, P.; Monserrate, M.; Olleros Rodríguez, P.; Pérez Magán, D. L.

    2018-03-01

    A compact, portable and large field-of-view gamma camera that is able to identify, locate and quantify gamma-ray emitting radioisotopes in real-time has been developed. The device delivers spectroscopic and imaging capabilities that enable its use it in a variety of nuclear waste characterisation scenarios, such as radioactivity monitoring in nuclear power plants and more specifically for the decommissioning of nuclear facilities. The technical development of this apparatus and some examples of its application in field measurements are reported in this article. The performance of the presented gamma-camera is also benchmarked against other conventional techniques.

  14. Nuclear X-ray emission after fusion of heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Berner, Christian; Muecher, Dennis; Gernhaeuser, Roman; Faestermann, Thomas [Technische Universitaet Muenchen, Lehrstuhl E12 (Germany); Henning, Walter [Technische Universitaet Muenchen, Lehrstuhl E12 (Germany); Argonne National Laboratory (United States); Morita, Kosuke; Morimoto, Kouji; Kaji, Daija [RIKEN, Research Group for Superheavy Elements (Japan)

    2015-07-01

    The goal is to establish in-beam K-X-ray spectroscopy as a sensitive tool to identify super heavy elements (SHEs) produced in fusion reactions via their proton number. SHEs, formed after cold or hot fusion, are usually identified via the alpha-decay products, which have to be connected to well-known elements. In case of hot fusion, the daughter nuclei quickly undergo spontaneous fission, so that the identification of the produced SHEs is difficult. Using the hot fusion approach in our first test experiments, the resultant products will be analysed by the gas-filled GARIS separator at the RILAC facility at RIKEN. As the X-ray detector is required to have superior energy and timing resolution to best identify the rare events at highest masses and to supress random coincidences as sufficient as possible, we chose a thin and planar geometry, which also reduces the damage caused by fast neutrons. We show first measurements using the MINIBALL Ge array at Munich. Additionally we report on our feasibility studies and on first tests using the new detector at high count rates together with a powerful DAQ system and transistor reset preamplifiers.

  15. X-ray and nuclear radiation facilities: personnel safety features

    International Nuclear Information System (INIS)

    Mason, W.J.; Pipes, E.W.; Rucker, T.R.; Smith, D.N.; West, C.M.

    1976-10-01

    The Oak Ridge Y-12 Plant is a research and production installation. The nature and versatility of this work require the use of a large number and variety of x-ray and radiographic sources for nondestructive testing and material analyses. Presently, there are over 80 x-ray generators in the plant, which range in size from small, portable units which operate at a less than 50 kilovolts potential and 0.1 milliampere current to an electron linear accelerator which operates at 12-million electron volts and produces a radiation beam of such intensity that it could deliver a lethal dose to man in a fraction of a minute. There are also almost 50 gamma and neutron sources in use in the plant. These units range in size from a few millicuries to several hundred curies. Although the radiation safety at each of these facilities was considered adequate, the administrative and maintenance procedures became unduly complicated. Accordingly, engineering standards and uniform operating procedures were considered necessary to alleviate these complications and, in so doing, provide an improved measure of radiation safety. Development and implementation of these standards are described and the general philosophy and approach to these standards are outlined. Use of a matrix (type of installation versus radiation safety feature) to facilitate equipment classification and personnel safety feature requirements is presented. Included is a set of the standards showing formats, matrices, etc., and the detailed standards for each safety feature

  16. The nuclear spectroscopic telescope array (NuSTAR) high-energy X-ray mission

    DEFF Research Database (Denmark)

    Harrison, Fiona A.; Craig, William W.; Christensen, Finn Erland

    2013-01-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR) mission, launched on 2012 June 13, is the first focusing high-energy X-ray telescope in orbit. NuSTAR operates in the band from 3 to 79 keV, extending the sensitivity of focusing far beyond the ~10 keV high-energy cutoff achieved by all previous X...

  17. Time stamp technique using a nuclear emulsion multi-stage shifter for gamma-ray telescope

    International Nuclear Information System (INIS)

    Takahashi, Satoru; Aoki, Shigeki; Rokujo, Hiroki; Hamada, Kaname; Komatsu, Masahiro; Morishima, Kunihiro; Nakamura, Mitsuhiro; Nakano, Toshiyuki; Niwa, Kimio; Sato, Osamu; Yoshioka, Teppei; Kodama, Koichi

    2010-01-01

    Nuclear emulsion has a potential use as a gamma-ray telescope with high angular resolution. For this application it is necessary to know the time when each track was recorded in the emulsion. In previous experiments using nuclear emulsion, various efforts were used to associate time to nuclear emulsion tracks and to improve the time resolution. Using a high speed readout system for nuclear emulsion together with a clock-based multi-stage emulsion shifter, we invented a technique to give a time-stamp to emulsion tracks and greatly improve the time resolution. A test experiment with a 2-stage shifter was used to demonstrate the principle of multi-stage shifting, and we achieved a time resolution 1.5 s for 12.1 h (about 1 part in 29 000) with the time stamp reliability 97% and the time stamp efficiency 98%. This multi-stage shifter can achieve the time resolution required for a gamma-ray telescope and can also be applied to another cosmic ray observations and accelerator experiments using nuclear emulsion.

  18. Cosmic ray muon computed tomography of spent nuclear fuel in dry storage casks

    Science.gov (United States)

    Poulson, D.; Durham, J. M.; Guardincerri, E.; Morris, C. L.; Bacon, J. D.; Plaud-Ramos, K.; Morley, D.; Hecht, A. A.

    2017-01-01

    Radiography with cosmic ray muon scattering has proven to be a successful method of imaging nuclear material through heavy shielding. Of particular interest is monitoring dry storage casks for diversion of plutonium contained in spent reactor fuel. Using muon tracking detectors that surround a cylindrical cask, cosmic ray muon scattering can be simultaneously measured from all azimuthal angles, giving complete tomographic coverage of the cask interior. This paper describes the first application of filtered back projection algorithms, typically used in medical imaging, to cosmic ray muon scattering imaging. The specific application to monitoring spent nuclear fuel in dry storage casks is investigated via GEANT4 simulations. With a cylindrical muon tracking detector surrounding a typical spent fuel cask, simulations indicate that missing fuel bundles can be detected with a statistical significance of ∼ 18 σ in less than two days exposure and a sensitivity at 1σ to a 5% missing portion of a fuel bundle. Potential detector technologies and geometries are discussed.

  19. Equation of state of dense nuclear matter and neutron star structure from nuclear chiral interactions

    Science.gov (United States)

    Bombaci, Ignazio; Logoteta, Domenico

    2018-02-01

    Aims: We report a new microscopic equation of state (EOS) of dense symmetric nuclear matter, pure neutron matter, and asymmetric and β-stable nuclear matter at zero temperature using recent realistic two-body and three-body nuclear interactions derived in the framework of chiral perturbation theory (ChPT) and including the Δ(1232) isobar intermediate state. This EOS is provided in tabular form and in parametrized form ready for use in numerical general relativity simulations of binary neutron star merging. Here we use our new EOS for β-stable nuclear matter to compute various structural properties of non-rotating neutron stars. Methods: The EOS is derived using the Brueckner-Bethe-Goldstone quantum many-body theory in the Brueckner-Hartree-Fock approximation. Neutron star properties are next computed solving numerically the Tolman-Oppenheimer-Volkov structure equations. Results: Our EOS models are able to reproduce the empirical saturation point of symmetric nuclear matter, the symmetry energy Esym, and its slope parameter L at the empirical saturation density n0. In addition, our EOS models are compatible with experimental data from collisions between heavy nuclei at energies ranging from a few tens of MeV up to several hundreds of MeV per nucleon. These experiments provide a selective test for constraining the nuclear EOS up to 4n0. Our EOS models are consistent with present measured neutron star masses and particularly with the mass M = 2.01 ± 0.04 M⊙ of the neutron stars in PSR J0348+0432.

  20. Interaction of ultrahigh energy cosmic rays with microwave background radiation

    International Nuclear Information System (INIS)

    Aharonyan, F.A.; Kanevskij, B.L.; Vardanyan, V.V.

    1989-01-01

    The formation of the bump and black-body cutoff in the cosmic-ray (CR) spectrum arising from the π-meson photoproduction reaction in collisions of CR protons with the microwave background radiation (MBR) photons is studied. A kinetic equation which describes CR proton propagation in MBR with account of a catastrophic of the π-meson photoproduction process is derived. The equilibrium CR proton spectrum obtained from the solution of the stationary kinetic equation is in general agreement with spectrum obtained under assumption of continuous energy loss approximation. However spectra from local sources especially for the times of propagation t>10 9 years differ noticeably from those obtained in the continuous loss approximation. 24 refs.; 5 figs

  1. Nuclear medicine installations supervisors interactive course (CD-ROM)

    International Nuclear Information System (INIS)

    Williart, A.; Shaw, M.; Tellez, M.

    2000-01-01

    The professionals who work as Nuclear Medicine Installations Supervisors need a suitable training. This training must be based on the guidelines of the C.S.N. (the Spanish Agency for Nuclear Safety). The traditional training courses must comply with a set of requirements, that not always is possible to get: They are given in a settled place. They are developed during a time, more or less lengthy. This time is pre-established. However, the persons willing to follow these courses have some difficulties with the place and the time. Many of them do not live near the places where the courses are given, in general in big cities, while there are Nuclear Medicine Installations scattered through all Spain. Moreover in some occasions they have not available time to attend the courses. Many times, faced with so many obstacles, the option is not to do the suitable training course. In order to solve this kind of problems we offer an Interactive Training Course (supported by CD-ROM). The course contents are based on Spanish Regulations and on the Safety Guide, established by C.S.N., for approval Radioactive Installations Supervisors Training Courses. This guide includes General Topics for Radioactive Installations and Specific Subjects for Nuclear Medicine. (General topics) Basic knowledge on the fundamental concepts on the action and nature of Ionizing Radiations, their risks and preventions. The ionizing radiations. Biological effects of ionizing radiations. Radiological protection. Legislation on radioactive installations. (Specific Subjects) Knowledge on the radiological risks associated to the proper techniques in the specific field of application. In our case the specific field is Nuclear Medicine Installations, where the radioactive sources are used for diagnostic or for therapy. Specific legal and administrative aspects. Non-encapsulated radioactive sources. Associated radiological risks to the use of non-encapsulated sources. Installations design. Operative procedures

  2. Interactive virtual laboratory for distance education in nuclear engineering

    International Nuclear Information System (INIS)

    Jain, P.; Stubbins, J.; Uddin, R.

    2006-01-01

    A real time, distance lab module is being developed and implemented in the Dept. of Nuclear, Plasma and Radiological Engineering at the Univ. of Illinois at Urbana-Champaign. This internet based system allows remote personnel to watch the experiments, acquire data, and interact with on-site personnel. The e-lab broadcasts not only the live scenes of laboratory and experiments, but also the real time data and plots being measured and displayed in graphical and other formats. Moreover, use of LabVIEW's remote front panel feature allows communications between the local lab and remote client so that, if permitted, remote client can control part or all of the experiment in real-time. (authors)

  3. Interactive graphics analysis system for nuclear engineering applications

    International Nuclear Information System (INIS)

    Danchak, M.; Moyer, W.R.; Becker, M.

    1973-01-01

    From working with continuous slowing down theory, the need was recognized for a system which allowed rapid calculation of the theoretical flux, instant comparison with experiment and a simple means of iterating on the slowing down parameters to force flux agreement and reflect cross section modification. Similar requirements exist in other areas of nuclear work for streamlining and simplifying the data analysis process. As a solution, a unique interactive graphics analysis system (RIGAS) was devised to allow a user to calculate, display, compare, manipulate and modify his data without requiring any programming on his part. This was accomplished by establishing human primacy, through extensive human factor considerations, and designing a man-machine dialogue which responds to the mere push of a button. This system results in an instrument which maximizes man's decision making capability and the computer's speed to improve graphic communication and data analysis. (14 figs) (U.S.)

  4. Nuclear envelope and genome interactions in cell fate

    Science.gov (United States)

    Talamas, Jessica A.; Capelson, Maya

    2015-01-01

    The eukaryotic cell nucleus houses an organism’s genome and is the location within the cell where all signaling induced and development-driven gene expression programs are ultimately specified. The genome is enclosed and separated from the cytoplasm by the nuclear envelope (NE), a double-lipid membrane bilayer, which contains a large variety of trans-membrane and associated protein complexes. In recent years, research regarding multiple aspects of the cell nucleus points to a highly dynamic and coordinated concert of efforts between chromatin and the NE in regulation of gene expression. Details of how this concert is orchestrated and how it directs cell differentiation and disease are coming to light at a rapid pace. Here we review existing and emerging concepts of how interactions between the genome and the NE may contribute to tissue specific gene expression programs to determine cell fate. PMID:25852741

  5. Modelling operator cognitive interactions in nuclear power plant safety evaluation

    International Nuclear Information System (INIS)

    Senders, J.W.; Moray, N.; Smiley, A.; Sellen, A.

    1985-08-01

    The overall objectives of the study were to review methods which are applicable to the analysis of control room operator cognitive interactions in nuclear plant safety evaluations and to indicate where future research effort in this area should be directed. This report is based on an exhaustive search and review of the literature on NPP (Nuclear Power Plant) operator error, human error, human cognitive function, and on human performance. A number of methods which have been proposed for the estimation of data for probabilistic risk analysis have been examined and have been found wanting. None addresses the problem of diagnosis error per se. Virtually all are concerned with the more easily detected and identified errors of action. None addresses underlying cause and mechanism. It is these mechanisms which must be understood if diagnosis errors and other cognitive errors are to be controlled and predicted. We have attempted to overcome the deficiencies of earlier work and have constructed a model/taxonomy, EXHUME, which we consider to be exhaustive. This construct has proved to be fruitful in organizing our thinking about the kinds of error that can occur and the nature of self-correcting mechanisms, and has guided our thinking in suggesting a research program which can provide the data needed for quantification of cognitive error rates and of the effects of mitigating efforts. In addition a preliminary outline of EMBED, a causal model of error, is given based on general behavioural research into perception, attention, memory, and decision making. 184 refs

  6. Resonant Electromagnetic Interaction in Low Energy Nuclear Reactions

    Science.gov (United States)

    Chubb, Scott

    2008-03-01

    Basic ideas about how resonant electromagnetic interaction (EMI) can take place in finite solids are reviewed. These ideas not only provide a basis for conventional, electron energy band theory (which explains charge and heat transport in solids), but they also explain how through finite size effects, it is possible to create many of the kinds of effects envisioned by Giuliano Preparata. The underlying formalism predicts that the orientation of the external fields in the SPAWAR protocolootnotetextKrivit, Steven B., New Energy Times, 2007, issue 21, item 10. http://newenergytimes.com/news/2007/NET21.htm^,ootnotetextSzpak, S.; Mosier-Boss, P.A.; Gordon, F.E. Further evidence of nuclear reactions in the Pd lattice: emission of charged particles. Naturwissenschaften 94,511(2007)..has direct bearing on the emission of high-energy particles. Resonant EMI also implies that nano-scale solids, of a particular size, provide an optimal environment for initiating Low Energy Nuclear Reactions (LENR) in the PdD system.

  7. Nuclear interactions of high energy heavy ions and applications in astrophysics

    International Nuclear Information System (INIS)

    Wefel, J.P.

    1992-01-01

    This program was established for the purpose of studying projectile fragmentation; (1) as a function of energy, focusing first on the intermediate energy region, < 1 GeV/nucleon, where there have been few previous measurements and no systematic studies, and (2) as a function of projectile mass, starting with light beams and proceeding to species as heavy as nickel (and possibly beyond). The intermediate energy region is important as the transition between the lower energy data, where the interaction appears to be dominated by collective effects and the decay of excited nuclei, and the highest energy results, where nucleon-nucleon interactions are fundamental, ''limiting fragmentation'' applies, and the nucleus may well break-up before any de-excitation. The mass dependence of projectile fragmentation is largely unknown since most detailed work has involved light ion beams. Nuclear structure effects, for example, may well be quite prominent for heavier beams. Furthermore, the nuclear excitation functions for the production of different fragment isotopes have immediate application to the astrophysical interpretation of existing isotopic datasets obtained from balloon and satellite measurements of galactic cosmic rays

  8. Electron and nuclear spin interactions in the optical spectra of single GaAs quantum dots.

    Science.gov (United States)

    Gammon, D; Efros, A L; Kennedy, T A; Rosen, M; Katzer, D S; Park, D; Brown, S W; Korenev, V L; Merkulov, I A

    2001-05-28

    Fine and hyperfine splittings arising from electron, hole, and nuclear spin interactions in the magneto-optical spectra of individual localized excitons are studied. We explain the magnetic field dependence of the energy splitting through competition between Zeeman, exchange, and hyperfine interactions. An unexpectedly small hyperfine contribution to the splitting close to zero applied field is described well by the interplay between fluctuations of the hyperfine field experienced by the nuclear spin and nuclear dipole/dipole interactions.

  9. Nuclear interactions between cosmic radiation and interstellar gas, and nucleosynthesis of lithium, beryllium, and boron

    International Nuclear Information System (INIS)

    Meneguzzi, Maurice.

    1975-01-01

    The effects of nuclear interactions between the nuclei of cosmic radiation and those of interstellar gas were studied. The variation in the chemical composition of cosmic radiation with energy shows that the quantity of matter it passes through decreases between 1 and 100GeV/nucleon from 6 to 1g/cm 2 approximately. The chemical and isotopic composition for C, N and O suggests that the relative abundances of these nuclei at the source are much the same as the universal abundances except for the ratio C/O, higher by about a factor 1.5 in cosmic radiation sources. The enrichment of interstellar gas in light elements Li, Be and B was calculated. The value obtained accounts well for the universal abundances of the four isotopes 6 Li, 9 Be, 10 B, 11 B independently of the model used. It may be assumed that large fluxes of low-energy cosmic rays exist in the remains of supernovae and that 7 Li is produced in these objects and then spread out in the galaxy. These objects could be extended sources of nuclear γ's, which are observable, but the same process proves unable to produce sufficient quantities of the very heavy proton-rich elements of dubious origin. Inelastic collisions or spallation reactions between cosmic and interstellar gas nuclei induce a quantity of nuclear γ ray emission not necessarily undetectable. The position flux of a few MeV from the β + disintegration of unstable spallation products is too low on the other hand to give an estimate of the low-energy cosmic radiation flux in the interstellar medium [fr

  10. Interactive X-ray and proton therapy training and simulation.

    Science.gov (United States)

    Hamza-Lup, Felix G; Farrar, Shane; Leon, Erik

    2015-10-01

    External beam X-ray therapy (XRT) and proton therapy (PT) are effective and widely accepted forms of treatment for many types of cancer. However, the procedures require extensive computerized planning. Current planning systems for both XRT and PT have insufficient visual aid to combine real patient data with the treatment device geometry to account for unforeseen collisions among system components and the patient. The 3D surface representation (S-rep) is a widely used scheme to create 3D models of physical objects. 3D S-reps have been successfully used in CAD/CAM and, in conjunction with texture mapping, in the modern gaming industry to customize avatars and improve the gaming realism and sense of presence. We are proposing a cost-effective method to extract patient-specific S-reps in real time and combine them with the treatment system geometry to provide a comprehensive simulation of the XRT/PT treatment room. The X3D standard is used to implement and deploy the simulator on the web, enabling its use not only for remote specialists' collaboration, simulation, and training, but also for patient education. An objective assessment of the accuracy of the S-reps obtained proves the potential of the simulator for clinical use.

  11. X ray emission: a tool and a probe for laser - clusters interaction

    International Nuclear Information System (INIS)

    Prigent, Ch.

    2004-12-01

    In intense laser-cluster interaction, the experimental results show a strong energetic coupling between radiation and matter. We have measured absolute X-ray yields and charge state distributions under well control conditions as a function of physical parameters governing the interaction; namely laser intensity, pulse duration, wavelength or polarization state of the laser light, the size and the species of the clusters (Ar, Kr, Xe). We have highlighted, for the first time, an intensity threshold in the X-ray production very low (∼ 2.10 14 W/cm 2 for a pulse duration of 300 fs) which can results from an effect of the dynamical polarisation of clusters in an intense electric field. A weak dependence with the wavelength (400 nm / 800 nm) on the absolute X-ray yields has been found. Moreover, we have observed a saturation of the X-ray emission probability below a critical cluster size. (author)

  12. Human-machine interaction in nuclear power plants

    International Nuclear Information System (INIS)

    Yoshikawa, Hidekazu

    2005-01-01

    Advanced nuclear power plants are generally large complex systems automated by computers. Whenever a rate plant emergency occurs the plant operators must cope with the emergency under severe mental stress without committing any fatal errors. Furthermore, the operators must train to improve and maintain their ability to cope with every conceivable situation, though it is almost impossible to be fully prepared for an infinite variety of situations. In view of the limited capability of operators in emergency situations, there has been a new approach to preventing the human error caused by improper human-machine interaction. The new approach has been triggered by the introduction of advanced information systems that help operators recognize and counteract plant emergencies. In this paper, the adverse effect of automation in human-machine systems is explained. The discussion then focuses on how to configure a joint human-machine system for ideal human-machine interaction. Finally, there is a new proposal on how to organize technologies that recognize the different states of such a joint human-machine system

  13. GaAs low-energy X-ray radioluminescence nuclear battery

    Science.gov (United States)

    Zhang, Zheng-Rong; Liu, Yun-Peng; Tang, Xiao-Bin; Xu, Zhi-Heng; Yuan, Zi-Cheng; Liu, Kai; Chen, Wang

    2018-01-01

    The output properties of X-ray radioluminescence (RL) nuclear batteries with different phosphor layers were investigated by using low-energy X-ray. Results indicated that the values of electrical parameters increased as the X-ray energy increased, and the output power of nuclear battery with ZnS:Cu phosphor layer was greater than those of batteries with ZnS:Ag, (Zn,Cd)S:Cu or Y2O3:Eu phosphor layers under the same excitation conditions. To analyze the RL effects of the phosphor layers under X-ray excitation, we measured the RL spectra of the different phosphor layers. Their fluorescence emissions were absorbed by the GaAs device. In addition, considering luminescence utilization in batteries, we introduced an aluminum (Al) film between the X-ray emitter and phosphor layer. Al film is a high performance reflective material and can increase the fluorescence reaching the GaAs photovoltaic device. This approach significantly improved the output power of the battery.

  14. The interaction of x-rays and antimalarials

    International Nuclear Information System (INIS)

    Geoghegan, D.S.; Skinner-Adams, T.; Davis, T.M.E.

    2001-01-01

    Full text: The radiation sensitivity of malaria parasites has three potential clinical applications, namely i) to prevent the transmission of malaria by blood transfusion, ii) as adjunctive therapy when a radioactive isotope is complexed to a conventional antimalarial drug, and iii) to attenuate the pathogenicity of specific parasite stages as part of the development of a vaccine. In the first two applications, detailed information relating to parasite radiosensitivity and the interaction of ionising radiation with antimalarials is of vital importance because dosimetry must allow for the exposure of normal cells. Malaria parasite cultures (Plasmodium falciparum) were exposed to a logarithmic series of concentrations of antimalarial agents and irradiated using a Siemens Stabilipan orthovoltage radiotherapy unit. The irradiation was performed at room temperature and ambient oxygen concentration. Control samples were also irradiated. The DNA synthesis in each culture was measured 48 hours post irradiation by using a 3 H-hypoxanthine incorporation assay. The antimalarials studied are: artesunate, quinine, retinol and chloroquine. The radiosensitivity of Plasmodium falciparum is not dependent on the strain of parasite with the dose required to inhibit 50% of DNA synthesis (ID 50 ) equal to 24.7 ± 3.0 Gy. This applies equally for the drug resistant and drug sensitive strains studied. Because the measured radiosensitivity is dependent on the sera oxygen concentration, the reported value for the ID 50 may not apply in hypoxic situations. The interaction of ionising radiation with the antimalarials shows synergy with retinol and choloquine, additivity with quinine and slight antagonism with artesunate. Radionuclide therapy may emerge as a novel treatment for malaria. If this does occur, then, although all strains appear to be equally radiosensitive, care must be taken when combining ionising radiation with existing antimalarials for the treatment of malaria. Copyright

  15. Search for Erzion nuclear catalysis chains from cosmic ray Erzions stopping in organic scintillator

    International Nuclear Information System (INIS)

    Bazhutov, Yu.N.; Pletnikov, E.V.

    2006-01-01

    In the framework of Erzion model, charged cosmic ray Erzions stopping in organic substance begin to create Erzion nuclear catalysis chains with frequency of ∼ 100 MHz during ∼ 10-100 ms. Using an organic substance (plastic) scintillator we can observe long and flat (10-100 ms) pulses of large amplitude (∼100 MeV). No elementary particle can imitate such pulses. It is expected that such pulses in a plastic scintillator with mass of 100 kg will appear at the sea level every week. Such pulses can be observed every day with the Spectrometric Scintillation Super-Telescope (SSTIS) built at IZMIRAN for cosmic rays monitoring. (authors)

  16. Nuclear and particle physics with inverse compton γ-ray beam

    International Nuclear Information System (INIS)

    Fujiwara, Mamoru

    2004-01-01

    A new facility for GeV γ-ray beams in the energy range of 1.5 - 2.4 GeV is now used to develop hadron physics, and lead to an important finding of ''Penta-quark'' hadron, Θ + particle at 1540 MeV. The experimental results to observe φ and K + mesons guide us to a new look of quark dynamics with strangeness quarks. A beam line for MeV γ-rays is discussed in view of the observation of the parity violation due to the weak-strong coupling in nuclear medium. (author)

  17. Direct interaction in nuclear reactions: a theory; L'interaction directe dans les reactions nucleaires: theorie

    Energy Technology Data Exchange (ETDEWEB)

    Dominicis, C.T. de [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    General treatment of the foundations of direct interaction in nuclear reactions; representation of the instantaneous elastic scattering amplitude by the scattering amplitude due to a complex potential; expansion of the instantaneous inelastic scattering amplitude and discussion of the 1. Bohr approximation (distorted waves) contribution to individual and collective states of excitation. (author) [French] Expose general sur les fondements de l'interaction directe dans les reactions nucleaires; representation de l'amplitude de diffusion instantanee elastique par celle due a un potentiel complexe; developpement de l'amplitude de diffusion instantanee inelastique et discussion de la contribution de la premiere approximation de Bohr (sur des distendues) a l'excitation d'etats individuels et collectifs. (auteur)

  18. Composition of medium energy cosmic rays from silicon to nickel measured with nuclear emulsion

    International Nuclear Information System (INIS)

    Behrnetz, S.; Kristiansson, K.; Lindstam, S.; Soederstroem, K.

    1975-12-01

    The cosmic ray charge spectrum has been studied in three nuclear emulsion stacks exposed in balloon flights from Fort Churchill, Canada, in 1967 and 1970. The charge region is 14 <= Z < E 28 and the energy interval is about 400-800 MeV/Nucleon. The particles are identified by measurements with a nuclear track photometer which is described in some detail. The charge spectrum is extrapolated to the top of the atmosphere and comparisons with other measurements are made. Special emphasis is put on the abundance ratios (Sc-Mn)/Fe, (Sc+Ti)/(V+Cr) and Ni/Fe. (Auth.)

  19. Chemical Characterization of Nuclear Materials: Development a New Combined X-Ray Fluorescence and Raman Spectrometer

    International Nuclear Information System (INIS)

    Szaloki, I.; Gerenyi, A.

    2015-01-01

    New mobile analytical device based on combination of X-ray fluorescence and Raman spectrometer has been developed for prompt and quantitative characterization of chemical component from Al to U in nuclear waste or undeclared materials. The excitation source of the X-ray fluorescence spectrometer is an air-cooled X-ray tube with Ag transmission anode. For collection of secondary X-ray photons and data processing, a compact Amptek X-ray detector system is applied with silicon drift X-ray detector. The XRF system operates in confocal mode with focal volume around 1-4 mm 3 . Varying the geometrical position and orientation of the sample optional part of its surface can be analyzed. The Raman unit includes thermoelectrically cooled laser source having 500 mW power at wavelength 785 nm. In order to obtain spectral information from sample surface a reflection-type probe is connected by optical fibres to the Raman spectrometer. A mini focusing optics is set up to the sensor-fibre that provides the system to operate as confocal optical device in reflection mode. The XRF spectrometer with X-ray detector, Raman probe and X-ray tube are mechanically fixed and hermetically connected to an aluminium chamber, which can be optionally filled with helium. The chamber is mounted on a vertical stage that provides moving it to the sample surface. A new model and computer code have been developed for XRF quantitative analysis which describes the mathematical relationship between the concentration of sample elements and their characteristic X-ray intensities. For verification of the calculations standard reference alloy samples were measured. The results was in good agreement with certified concentrations in range of 0.001-100 w%. According to these numerical results this new method is successfully applicable for quick and non-destructive quantitative analysis of waste materials without using standard samples. (author)

  20. Resonant Interaction, Approximate Symmetry, and Electromagnetic Interaction (EMI) in Low Energy Nuclear Reactions (LENR)

    Science.gov (United States)

    Chubb, Scott

    2007-03-01

    Only recently (talk by P.A. Mosier-Boss et al, in this session) has it become possible to trigger high energy particle emission and Excess Heat, on demand, in LENR involving PdD. Also, most nuclear physicists are bothered by the fact that the dominant reaction appears to be related to the least common deuteron(d) fusion reaction,d+d ->α+γ. A clear consensus about the underlying effect has also been illusive. One reason for this involves confusion about the approximate (SU2) symmetry: The fact that all d-d fusion reactions conserve isospin has been widely assumed to mean the dynamics is driven by the strong force interaction (SFI), NOT EMI. Thus, most nuclear physicists assume: 1. EMI is static; 2. Dominant reactions have smallest changes in incident kinetic energy (T); and (because of 2), d+d ->α+γ is suppressed. But this assumes a stronger form of SU2 symmetry than is present; d+d ->α+γ reactions are suppressed not because of large changes in T but because the interaction potential involves EMI, is dynamic (not static), the SFI is static, and because the two incident deuterons must have approximate Bose Exchange symmetry and vanishing spin. A generalization of this idea involves a resonant form of reaction, similar to the de-excitation of an atom. These and related (broken gauge) symmetry EMI effects on LENR are discussed.

  1. Nuclear Gamma-Ray Spectroscopy at the Limit of Particle Stability

    International Nuclear Information System (INIS)

    Dr. Norbert Pietralla

    2006-01-01

    The research project ''Nuclear Gamma-Ray Spectroscopy at the Limit of Particle Stability'' with sponsor ID ''DE-FG02-04ER41334'' started late-summer 2004 and aims at the investigation of highly excited low-spin states of selected key-nuclei in the vicinity of the particle separation threshold by means of high-resolution gamma-ray spectroscopy in electromagnetic excitation reactions. This work addresses nuclear structures with excitation energies close to the binding energy or highly excited off-yrast states in accordance with the NSAC milestones. In 2005 the program was extended towards additional use of virtual photons and theoretical description of the low-lying collective excitations in the well deformed nuclei

  2. Collective effective dose in Europe from x-ray and nuclear medicine procedures

    International Nuclear Information System (INIS)

    Bly, R.; Jaervinen, H.; Jahnen, A.; Olerud, H.; Vassileva, J.; Vogiatzi, S.

    2015-01-01

    Population doses from radiodiagnostic (X-ray and nuclear medicine) procedures in Europe were estimated based on data collected from 36 European countries. For X-ray procedures in EU and EFTA countries (except Liechtenstein) the collective effective dose is 547 500 man Sv, resulting in a mean effective dose of 1.06 mSv per caput. For all European countries included in the survey the collective effective dose is 605 000 man Sv, resulting in a mean effective dose of 1.05 mSv per caput. For nuclear medicine procedures in EU countries and EFTA (except Liechtenstein) countries the collective effective dose is 30 700 man Sv, resulting in a mean effective dose of 0.06 mSv per caput. For all European countries included in the survey the collective effective dose is 31 100 man Sv, resulting in a mean effective dose of 0.05 mSv per caput. (authors)

  3. Energetic electron processes fluorescence effects for structured nanoparticles X-ray analysis and nuclear medicine applications

    Energy Technology Data Exchange (ETDEWEB)

    Taborda, A.; Desbrée, A. [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-HOM/SDI/LEDI, BP-17, 31, Avenue de la Division Leclerc, 92262 Fontenay-aux-Roses (France); Carvalho, A. [IEQUALTECS, Lda, Rua Dr. Francisco Sá Carneiro, 36, 2500-065 S. Gregório CLD (Portugal); Chaves, P.C. [C" 2TN, Campus Tecnológico e Nuclear, Instituto Superior Técnico, Universidade de Lisboa, EN10 km 139.7, 2685-066 Bobadela LRS (Portugal); Reis, M.A., E-mail: mareis@ctn.tecnico.ulisboa.pt [IEQUALTECS, Lda, Rua Dr. Francisco Sá Carneiro, 36, 2500-065 S. Gregório CLD (Portugal); C" 2TN, Campus Tecnológico e Nuclear, Instituto Superior Técnico, Universidade de Lisboa, EN10 km 139.7, 2685-066 Bobadela LRS (Portugal)

    2016-08-15

    Superparamagnetic iron oxide (SPIO) nanoparticles are widely used as contrast agents for nuclear magnetic resonance imaging (MRI), and can be modified for improved imaging or to become tissue-specific or even protein-specific. The knowledge of their detailed elemental composition characterisation and potential use in nuclear medicine applications, is, therefore, an important issue. X-ray fluorescence techniques such as particle induced X-ray emission (PIXE) or X-ray fluorescence spectrometry (XRF), can be used for elemental characterisation even in problematic situations where very little sample volume is available. Still, the fluorescence coefficient of Fe is such that, during the decay of the inner-shell ionised atomic structure, keV Auger electrons are produced in excess to X-rays. Since cross-sections for ionisation induced by keV electrons, for low atomic number atoms, are of the order of 10{sup 3} barn, care should be taken to account for possible fluorescence effects caused by Auger electrons, which may lead to the wrong quantification of elements having atomic number lower than the atomic number of Fe. Furthermore, the same electron processes will occur in iron oxide nanoparticles containing {sup 57}Co, which may be used for nuclear medicine therapy purposes. In the present work, simple approximation algorithms are proposed for the quantitative description of radiative and non-radiative processes associated with Auger electrons cascades. The effects on analytical processes and nuclear medicine applications are quantified for the case of iron oxide nanoparticles, by calculating both electron fluorescence emissions and energy deposition on cell tissues where the nanoparticles may be embedded.

  4. Measurement of plutonium in spent nuclear fuel by self-induced x-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Hoover, Andrew S [Los Alamos National Laboratory; Rudy, Cliff R [Los Alamos National Laboratory; Tobin, Steve J [Los Alamos National Laboratory; Charlton, William S [Los Alamos National Laboratory; Stafford, A [TEXAS A& M; Strohmeyer, D [TEXAS A& M; Saavadra, S [ORNL

    2009-01-01

    Direct measurement of the plutonium content in spent nuclear fuel is a challenging problem in non-destructive assay. The very high gamma-ray flux from fission product isotopes overwhelms the weaker gamma-ray emissions from plutonium and uranium, making passive gamma-ray measurements impossible. However, the intense fission product radiation is effective at exciting plutonium and uranium atoms, resulting in subsequent fluorescence X-ray emission. K-shell X-rays in the 100 keV energy range can escape the fuel and cladding, providing a direct signal from uranium and plutonium that can be measured with a standard germanium detector. The measured plutonium to uranium elemental ratio can be used to compute the plutonium content of the fuel. The technique can potentially provide a passive, non-destructive assay tool for determining plutonium content in spent fuel. In this paper, we discuss recent non-destructive measurements of plutonium X-ray fluorescence (XRF) signatures from pressurized water reactor spent fuel rods. We also discuss how emerging new technologies, like very high energy resolution microcalorimeter detectors, might be applied to XRF measurements.

  5. Establishment of Imaging Spectroscopy of Nuclear Gamma-Rays based on Geometrical Optics.

    Science.gov (United States)

    Tanimori, Toru; Mizumura, Yoshitaka; Takada, Atsushi; Miyamoto, Shohei; Takemura, Taito; Kishimoto, Tetsuro; Komura, Shotaro; Kubo, Hidetoshi; Kurosawa, Shunsuke; Matsuoka, Yoshihiro; Miuchi, Kentaro; Mizumoto, Tetsuya; Nakamasu, Yuma; Nakamura, Kiseki; Parker, Joseph D; Sawano, Tatsuya; Sonoda, Shinya; Tomono, Dai; Yoshikawa, Kei

    2017-02-03

    Since the discovery of nuclear gamma-rays, its imaging has been limited to pseudo imaging, such as Compton Camera (CC) and coded mask. Pseudo imaging does not keep physical information (intensity, or brightness in Optics) along a ray, and thus is capable of no more than qualitative imaging of bright objects. To attain quantitative imaging, cameras that realize geometrical optics is essential, which would be, for nuclear MeV gammas, only possible via complete reconstruction of the Compton process. Recently we have revealed that "Electron Tracking Compton Camera" (ETCC) provides a well-defined Point Spread Function (PSF). The information of an incoming gamma is kept along a ray with the PSF and that is equivalent to geometrical optics. Here we present an imaging-spectroscopic measurement with the ETCC. Our results highlight the intrinsic difficulty with CCs in performing accurate imaging, and show that the ETCC surmounts this problem. The imaging capability also helps the ETCC suppress the noise level dramatically by ~3 orders of magnitude without a shielding structure. Furthermore, full reconstruction of Compton process with the ETCC provides spectra free of Compton edges. These results mark the first proper imaging of nuclear gammas based on the genuine geometrical optics.

  6. Application of the nuclear x-ray fluorescence method to prospecting for gold in-situ

    International Nuclear Information System (INIS)

    Zhang, Y.; Xie, T.; Zhou, S.; Ge, L.

    1989-01-01

    Arsenic and chalcophile elements are often associated with gold, and can be considered indicator elements when prospecting for gold deposits. The nuclear geophysics X-ray fluorescence method can be used to search for hidden gold deposits by measuring fluorescence intensities of the indicator elements in situ. The method can speed geologic investigation and reduce exploration cost. Three types of portable radioisotope X-ray fluorescence analyzers, designed and manufactured by Chengdu College of Geology and Chongqing Geological Instrument Factory, are briefly introduced. These analyzers are widely used in different stages of geologic investigation for gold in China. In the two case histories presented five anomalous zones of X-ray fluorescence intensity related to gold mineralization are located and one hidden gold deposit is discovered with gold content of 23 g/t

  7. Interactions of Cosmic Rays around the Universe. Models for UHECR data interpretation

    Directory of Open Access Journals (Sweden)

    Boncioli Denise

    2017-01-01

    Full Text Available Ultra high energy cosmic rays (UHECRs are expected to be accelerated inastrophysical sources and to travel through extragalactic space before hitting the Earth atmosphere. They interact both with the environment in the source and with the intergalactic photon fields they encounter, causing different processes at various scales depending on the photon energy in the nucleus rest frame. UHECR interactions are sensitive to uncertainties in the extragalactic background spectrum and in the photo-disintegration models.

  8. Inverse Compton gamma-ray source for nuclear physics and related applications at the Duke FEL

    International Nuclear Information System (INIS)

    O'Shea, P.G.; Litvinenko, V.N.; Madey, J.M.J.

    1995-01-01

    In recent years the development of intense, short-wavelength FEL light sources has opened opportunities for the development new applications of high-energy Compton-backscattered photons. These applications range from medical imaging with X-ray photons to high-energy physics with γγ colliders. In this paper we discuss the possibilities for nuclear physics studies using polarized Compton backscattered γ-rays from the Duke storage-ring-driven UV-FEL. There are currently a number of projects that produce polarized γ-rays for nuclear physics studies. All of these facilities operate by scattering conventional laser-light against electrons circulating in a storage ring. In our scheme, intra-cavity scattering of the UV-FEL light will produce a γ-flux enhancement of approximately 10 3 over existing sources. The Duke ring can operate at energies up to 1.2 GeV and can produce FEL photons up to 12.5 eV. We plan to generate γ-rays up to 200 MeV in energy with an average flux in excess of 10 7 /s/MeV, using a modest scattering beam of 10-mA average stored current. The γ-ray energy may be tuned by varying the FEL wavelength or by adjusting the stored electron beam energy. Because of the intense flux, we can eliminate the need for photon energy tagging by collimating of the γ-ray beam. We will discuss the characteristics of the device and its research opportunities

  9. Studies of neutron emission from relativistic nuclear interactions

    CERN Document Server

    Guo, S L; Wang, Y L; Guo, H Y; Sá Ben-Hao; Zheng, Y M; Brandt, R; Vater, P; Wan, J S; Ochs, M; Kulakov, B A; Sosnin, A N; Krivopustov, M I; Butsev, V S; Bradnova, V

    1999-01-01

    Studies were carried out on the yields and spatial distributions of secondary neutrons produced in the relativistic nuclear interactions of 1.5 GeV to 14.4 GeV projectiles p, d and alpha-particles with targets Pb and U/Pb. CR-39 track detectors were used to measure the neutrons. It shows that: (1) Secondary neutrons are produced in the whole length of Pb or U targets having a thickness of 20 cm. The neutron intensities produced by proton bombardments are reduced along the proton beam direction in the targets. The higher the energy of protons, the lower the reduction rate of the neutrons. The reduction rate of neutrons in U target is higher than in Pb target for the same energy of protons. (2) The radial intensities of neutrons decrease as the distance increases from the target central line. (3) The neutron yield in U target by proton bombardments is approx 55% higher than in Pb target. (4) The ratio of neutron yield by 14.4 GeV alpha to 7.3 GeV d bombardment in Pb target is 1.74+-0.20.

  10. Heat energy from hydrogen-metal nuclear interactions

    Energy Technology Data Exchange (ETDEWEB)

    Hadjichristos, John [Defkalion GT SA, 1140 Homer Street, Suite 250, Vancouver BC V682X6 (Canada); Gluck, Peter [Retired from INCDTIM Cluj-Napoca in 1999 (Romania)

    2013-11-13

    The discovery of the Fleischmann-Pons Effect in 1989, a promise of an abundant, cheap and clean energy source was premature in the sense that theoretical knowledge, relative technologies and the experimental tools necessary for understanding and for scale-up still were not available. Therefore the field, despite efforts and diversification remained quasi-stagnant, the effect (a scientific certainty) being of low intensity leading to mainstream science to reject the phenomenon and not supporting its study. Recently however, the situation has changed, a new paradigm is in statunascendi and the obstacles are systematically removed by innovative approaches. Defkalion, a Greek company (that recently moved in Canada for faster progress) has elaborated an original technology for the Ni-H system [1-3]. It is about the activation of hydrogen and creation of nuclear active nano-cavities in the metal through a multi-stage interaction, materializing some recent breakthrough announcements in nanotechnology, superconductivity, plasma physics, astrophysics and material science. A pre-industrial generator and a novel mass-spectrometry instrumentations were created. Simultaneously, a meta-theory of phenomena was sketched in collaboration with Prof. Y. Kim (Purdue U)

  11. Nuclear many-body problem with repulsive hard core interactions

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, L M

    1965-07-01

    The nuclear many-body problem is considered using the perturbation-theoretic approach of Brueckner and collaborators. This approach is outlined with particular attention paid to the graphical representation of the terms in the perturbation expansion. The problem is transformed to centre-of-mass coordinates in configuration space and difficulties involved in ordinary methods of solution of the resulting equation are discussed. A new technique, the 'reference spectrum method', devised by Bethe, Brandow and Petschek in an attempt to simplify the numerical work in presented. The basic equations are derived in this approximation and considering the repulsive hard core part of the interaction only, the effective mass is calculated at high momentum (using the same energy spectrum for both 'particle' and 'hole' states). The result of 0.87m is in agreement with that of Bethe et al. A more complete treatment using the reference spectrum method in introduced and a self-consistent set of equations is established for the reference spectrum parameters again for the case of hard core repulsions. (author)

  12. Heat energy from hydrogen-metal nuclear interactions

    International Nuclear Information System (INIS)

    Hadjichristos, John; Gluck, Peter

    2013-01-01

    The discovery of the Fleischmann-Pons Effect in 1989, a promise of an abundant, cheap and clean energy source was premature in the sense that theoretical knowledge, relative technologies and the experimental tools necessary for understanding and for scale-up still were not available. Therefore the field, despite efforts and diversification remained quasi-stagnant, the effect (a scientific certainty) being of low intensity leading to mainstream science to reject the phenomenon and not supporting its study. Recently however, the situation has changed, a new paradigm is in statunascendi and the obstacles are systematically removed by innovative approaches. Defkalion, a Greek company (that recently moved in Canada for faster progress) has elaborated an original technology for the Ni-H system [1-3]. It is about the activation of hydrogen and creation of nuclear active nano-cavities in the metal through a multi-stage interaction, materializing some recent breakthrough announcements in nanotechnology, superconductivity, plasma physics, astrophysics and material science. A pre-industrial generator and a novel mass-spectrometry instrumentations were created. Simultaneously, a meta-theory of phenomena was sketched in collaboration with Prof. Y. Kim (Purdue U)

  13. Comparative analysis among X-ray mammographic findings, nuclear and histologic grading, and TNM staging of breast carcinoma

    International Nuclear Information System (INIS)

    Park, Jin Sook; Sung, Ki Joon; Cho, Mee Yon; Hong, In Soo; Kim, Myung Soon; Oh, Ki Keun

    1996-01-01

    The purpose of this study was to evaluate the prognosis of breast carcinoma by comparison with X-ray mammographic findings, nuclear and histologic grade, and TNM staging. We retrospectively reviewed 114 cases (113 patients) of breast carcinoma, analysing X-ray mammographic findings of all cases with regard to mass, calcification, and spiculation. In 80 cases of scirrhous invasive ductal breast carcinoma. Black's nuclear and Bloom-Richardson's histologic grade were also evaluated. Mammographic findings and nuclear and histologic grade were compared with TNM staging which might suggest the prognosis of breast carcinoma. X-ray mammographic findings (mass, calcification and spiculation) did not significantly correlate with T staging, but the clinical staging of the spiculation was advanced. These X-ray findings did not significantly correlate with the nuclear grading and the histologic grading. Nuclear grade did not correlate with T and M staging, but correlated significantly with N staging and clinical stage(p < 0.05). Histologic grade did not significantly correlate with TNM staging. The clinical staging of spiculation was advanced and nuclear grade correlated significantly with N stage and clinical staging. X-ray mammographic findings did not directly correlate with nuclear and histologic grading, but combined studies of the evaluation of mammographic findings and nuclear and histologic grade were useful for prognosing breast carcinoma

  14. The nuclear interaction analysis methods for diagnostics of high power ion beam technologies

    Energy Technology Data Exchange (ETDEWEB)

    Ryzhkov, V A; Grushin, I I; Remnev, G E [Nuclear Physics Inst., Tomsk (Russian Federation)

    1997-12-31

    The complex of Nuclear Interaction Analysis Methods including charged particle activation analysis (CPAA and HIAA), spectrometry of ion induced gamma-emission (PIGE and HIIGE) , characteristic X-ray emission (PIXE), and Rutherford Backscattering Spectrometry (RBS), have been used for diagnostics of the High Power Ion Beam (HPIB) assisted technologies. Accelerated ion beams from the EG-2.5 electrostatic generator and U-120 cyclotron were used for implementation of the techniques. The complex allows a lot of problems of elemental and isotopic analysis to be addressed. First, it is the determination of micro- and macrocomponents of modified materials; second, determination of surface density of thin films, multilayers and coatings, total surface gaseous contamination and amounts of the elements implanted in specimens; third, measurement of concentration depth profiles of the elements. Experiments have shown that the preferable application of nuclear analysis methods allows us to avoid the considerable errors arising when the concentration depth profiles of elements are measured by SIMS or AES in studies of mass transfer processes induced by HPIBs. (author). 1 tab., 2 figs., 3 refs.

  15. ANALYSIS AND MITIGATION OF X-RAY HAZARD GENERATED FROM HIGH INTENSITY LASER-TARGET INTERACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, R.; Liu, J.C.; Prinz, A.A.; Rokni, S.H.; Woods, M.; Xia, Z.; /SLAC

    2011-03-21

    Interaction of a high intensity laser with matter may generate an ionizing radiation hazard. Very limited studies have been made, however, on the laser-induced radiation protection issue. This work reviews available literature on the physics and characteristics of laser-induced X-ray hazards. Important aspects include the laser-to-electron energy conversion efficiency, electron angular distribution, electron energy spectrum and effective temperature, and bremsstrahlung production of X-rays in the target. The possible X-ray dose rates for several femtosecond Ti:sapphire laser systems used at SLAC, including the short pulse laser system for the Matter in Extreme Conditions Instrument (peak power 4 TW and peak intensity 2.4 x 10{sup 18} W/cm{sup 2}) were analysed. A graded approach to mitigate the laser-induced X-ray hazard with a combination of engineered and administrative controls is also proposed.

  16. Interaction of electromagnetic pulse with commercial nuclear-power-plant systems

    Energy Technology Data Exchange (ETDEWEB)

    Ericson, D.M. Jr.; Strawe, D.F.; Sandberg, S.J.; Jones, V.K.; Rensner, G.D.; Shoup, R.W.; Hanson, R.J.; Williams, C.B.

    1983-02-01

    This study examines the interaction of the electromagnetic pulse from a high altitude nuclear burst with commercial nuclear power plant systems. The potential vulnerability of systems required for safe shutdown of a specific nuclear power plant are explored. EMP signal coupling, induced plant response and component damage thresholds are established using techniques developed over several decades under Defense Nuclear Agency sponsorship. A limited test program was conducted to verify the coupling analysis technique as applied to a nuclear power plant. The results are extended, insofar as possible, to other nuclear plants.

  17. Interaction of electromagnetic pulse with commercial nuclear-power-plant systems

    International Nuclear Information System (INIS)

    Ericson, D.M. Jr.; Strawe, D.F.; Sandberg, S.J.; Jones, V.K.; Rensner, G.D.; Shoup, R.W.; Hanson, R.J.; Williams, C.B.

    1983-02-01

    This study examines the interaction of the electromagnetic pulse from a high altitude nuclear burst with commercial nuclear power plant systems. The potential vulnerability of systems required for safe shutdown of a specific nuclear power plant are explored. EMP signal coupling, induced plant response and component damage thresholds are established using techniques developed over several decades under Defense Nuclear Agency sponsorship. A limited test program was conducted to verify the coupling analysis technique as applied to a nuclear power plant. The results are extended, insofar as possible, to other nuclear plants

  18. RADIO AND X-RAY OBSERVATIONS OF SN 2006jd: ANOTHER STRONGLY INTERACTING TYPE IIn SUPERNOVA

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, Poonam [Department of Physics, Royal Military College of Canada, Kingston, ON K7K 7B4 (Canada); Chevalier, Roger A.; Irwin, Christopher M. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Chugai, Nikolai [Institute of Astronomy of Russian Academy of Sciences, Pyatnitskaya Street 48, 109017 Moscow (Russian Federation); Fransson, Claes [Department of Astronomy, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Soderberg, Alicia M. [Smithsonian Astrophysical Observatory, 60 Garden Street, MS-20, Cambridge, MA 02138 (United States); Chakraborti, Sayan [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Colaba, Mumbai 400005 (India); Immler, Stefan, E-mail: Poonam.Chandra@rmc.ca [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2012-08-20

    We report four years of radio and X-ray monitoring of the Type IIn supernova SN 2006jd at radio wavelengths with the Very Large Array, Giant Metrewave Radio Telescope, and Expanded Very Large Array; at X-ray wavelengths with Chandra, XMM-Newton, and Swift-XRT. We assume that the radio and X-ray emitting particles are produced by shock interaction with a dense circumstellar medium. The radio emission shows an initial rise that can be attributed to free-free absorption by cool gas mixed into the nonthermal emitting region; external free-free absorption is disfavored because of the shape of the rising light curves and the low gas column density inferred along the line of sight to the emission region. The X-ray luminosity implies a preshock circumstellar density {approx}10{sup 6} cm{sup -3} at a radius r {approx} 2 Multiplication-Sign 10{sup 16} cm, but the column density inferred from the photoabsorption of X-rays along the line of sight suggests a significantly lower density. The implication may be an asymmetry in the interaction. The X-ray spectrum shows Fe line emission at 6.9 keV that is stronger than is expected for the conditions in the X-ray emitting gas. We suggest that cool gas mixed into the hot gas plays a role in the line emission. Our radio and X-ray data both suggest the density profile is flatter than r{sup -2} because of the slow evolution of the unabsorbed emission.

  19. Investigation Study on Gamma Ray Imaging Technology for Nuclear Power Plant Decommissioning

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Guk; Jeong, Woo Tae [Machinery and Materials Laboratory, Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2014-10-15

    The gamma ray imaging system provides an estimated dose-rate of the source at 30 cm above. The gamma detector is a terbium activated glass scintillator. The system is capable of producing a color two dimensional image of a radiation field superimposed on a black and white visual image. The system used in US power plants consists of a portable sensor head that contains both gamma ray and visual imaging systems and a portable control computer. The gamma ray imaging system has been successfully used as an ALARA tool for identifying source terms and determining the adequacy of existing shielding. Because the control system can be positioned away from the camera, the radiation exposure to personnel can be reduced without extensive shielding requirements. The gamma ray imaging system has been used to date in the decommissioning of Maine Yankee, Big Rock point,Trojan, San Onofre1, and Millstone 1. The equipment has also been used at normal refueling outages at a number of commercial nuclear power plants and at several Department of Energy Decommissioning sites. This paper is intended to review the applicability of gamma ray imaging system as decommissioning tool. In order to review the actual applicability, we are going to introduce applications for US power plants.

  20. Study of electrons distribution produced by laser-plasma interaction on x-ray generation

    International Nuclear Information System (INIS)

    Nikzad, L.; Sadighi-Bonabi, R.

    2010-01-01

    Complete text of publication follows. In the present work, X-ray beams are generated from interaction of relativistic electron beams produced by interaction of 500 mJ, 30 femtosecond Ti:sapphire laser pulses with thin solid targets such as lead, molybdenum and tungsten. After interaction of an intense pulsed laser with He gas-jet, a micron-scale laser produced plasma, creates and accelerates electron bunches, which propagate in the ion channel produced in the wake of the laser pulse. When an electron bunch is injected into the bubble in phase with its field, it will gain relativistic energies within very short distance. These accelerated electrons with Megaelectron-Volt energy and different distributions, can interact with targets to generate X-ray radiation with Kiloelectron-Volt energy, providing to be close enough to the gas-jet, where the relativistic accelerated electrons exist. Here, to determine the results, Monte Carlo simulation (MCNP-4C code) is employed to present Bremsstrahlung and characteristic X-ray production by quasi-Maxwellian and quasi-monoenergetic electron beams for three samples with different thicknesses. The outcome shows that for one specific electron spectrum and one definite target, the energy which the maximum characteristic x-ray flux takes place, varies with thickness. Also, for each material the energy which this maximum happens is constant for all thicknesses, for both produced electron spectra. For each sample, x-ray flux is calculated for different thicknesses and the thickness which the maximum characteristic x-ray flux occurs is obtained. Besides, it is concluded that by increasing the atomic number of the target, maximum X-ray flux moves towards higher energy. Also, comparison of the results for three targets and two electron distributions shows that by using quasi-monoenergetic electron spectra, more intense and narrower characteristic X-ray can be produced compared to the quasi-Maxwellian electron distribution, almost for all

  1. Effects of film/foil interactions on X-ray image quality - experimental studies

    International Nuclear Information System (INIS)

    Maurer, H.J.; Goos, F.

    1985-01-01

    When assessing the quality of X-ray images, the interaction between film and foil should never be left out of account. Except for the case of green-emitting foils which require green-emitting films, films and foils are normally regarded separately, so that many variations are possible. The authors review the interaction between film and foil under practical aspects. Studies published so far have concentrated either on the amplification factor of foils or an the object imaging characteristics of certain films. Systematic studies on the interaction between film and foil have never been carried out. (orig.) [de

  2. X- and γ-ray interaction characteristics of Griffith, Alderson, Frigerio, Goodman and Rossi tissue substitutes

    International Nuclear Information System (INIS)

    Singh, V. P.; Badiger, N. M.; Vega C, H. R.

    2015-10-01

    Detailed information of radiation interaction, exposure and dose delivery to tissue substitutes is necessary for various branches of radiation physics. In the present investigation X- and γ-ray interaction characteristics of some tissue substitutes such as Griffith, Alderson, Frigerio, Goodman and Rossi have been studied and compared with standard tissues. Effective atomic numbers and air-kerma have been computed using mass attenuation coefficients and mass energy-absorption coefficients, respectively. Energy-absorption buildup factors for photon energy 0.015 to 15 MeV up to 40 mean free path were calculated using G-P fitting method. These investigations provide further information on the X- and γ-ray interaction of tissue substitutes for various applications in radiation physics and medical physics. (Author)

  3. X- and γ-ray interaction characteristics of Griffith, Alderson, Frigerio, Goodman and Rossi tissue substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Singh, V. P.; Badiger, N. M. [Karnatak University, Department of Physics, Dharwad-580003, Karnataka (India); Vega C, H. R., E-mail: kudphyvps@rediffmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2015-10-15

    Detailed information of radiation interaction, exposure and dose delivery to tissue substitutes is necessary for various branches of radiation physics. In the present investigation X- and γ-ray interaction characteristics of some tissue substitutes such as Griffith, Alderson, Frigerio, Goodman and Rossi have been studied and compared with standard tissues. Effective atomic numbers and air-kerma have been computed using mass attenuation coefficients and mass energy-absorption coefficients, respectively. Energy-absorption buildup factors for photon energy 0.015 to 15 MeV up to 40 mean free path were calculated using G-P fitting method. These investigations provide further information on the X- and γ-ray interaction of tissue substitutes for various applications in radiation physics and medical physics. (Author)

  4. A High Performance Block Eigensolver for Nuclear Configuration Interaction Calculations

    International Nuclear Information System (INIS)

    Aktulga, Hasan Metin; Afibuzzaman, Md.; Williams, Samuel; Buluc, Aydin; Shao, Meiyue

    2017-01-01

    As on-node parallelism increases and the performance gap between the processor and the memory system widens, achieving high performance in large-scale scientific applications requires an architecture-aware design of algorithms and solvers. We focus on the eigenvalue problem arising in nuclear Configuration Interaction (CI) calculations, where a few extreme eigenpairs of a sparse symmetric matrix are needed. Here, we consider a block iterative eigensolver whose main computational kernels are the multiplication of a sparse matrix with multiple vectors (SpMM), and tall-skinny matrix operations. We then present techniques to significantly improve the SpMM and the transpose operation SpMM T by using the compressed sparse blocks (CSB) format. We achieve 3-4× speedup on the requisite operations over good implementations with the commonly used compressed sparse row (CSR) format. We develop a performance model that allows us to correctly estimate the performance of our SpMM kernel implementations, and we identify cache bandwidth as a potential performance bottleneck beyond DRAM. We also analyze and optimize the performance of LOBPCG kernels (inner product and linear combinations on multiple vectors) and show up to 15× speedup over using high performance BLAS libraries for these operations. The resulting high performance LOBPCG solver achieves 1.4× to 1.8× speedup over the existing Lanczos solver on a series of CI computations on high-end multicore architectures (Intel Xeons). We also analyze the performance of our techniques on an Intel Xeon Phi Knights Corner (KNC) processor.

  5. Antiproton-nucleus interaction and nuclear E2 resonance effect in molybdenum and neodymium isotopes

    International Nuclear Information System (INIS)

    Kanert, W.

    1986-01-01

    Antiprotonix X-radiation from 92 Mo, 94 Mo, 95 Mo, 98 Mo, 100 Mo and 146 Nd, 148 Nd was measured with Ge detectors at the LEAR (CERN). The nuclear E2 resonance effect (configuration mixing by dynamic electric quadrupole interaction) was for the first time observed in antiprotonic atoms. It effects in 94 Mo, 95 Mo, and 98 Mo a mixing of the atomic levels (7,6) and (5,4). From the resulting weakening of the antiprotonic X-ray line (7→6) in comparison with the nonresonant isotope 92 Mo information on the effects of the strong interaction in the (5,4) level was obtained which is in Mo not directly observable. The absorption widths by strong interactions in the level (6,5) resulted for 92 Mo, 94 Mo, 95 Mo, and 98 Mo to 1.4±0.3 keV, 2.3±0.9 keV, 1.9±0.4 keV, and 2.3±0.7 keV, the energy shifts by strong interactions to 0.46±0.08 keV, 0.64±0.22 keV, 0.74±0.12 keV, and 0.55±0.16 keV. In the nonresonant isotope 92 Mo the absorption width of the level (7,6) to 19.5±1.2 eV. A fit of the effective scattering length to the data for 92 Mo resulted anti a = (0.25+3.05i) fm. In 100 Mo the predicted case of strong coupling could be experimentally established by the nearly complete extinction of the line (8→7) and the broadening of the line (9→8). In 148 Nd the nuclear E2 resonance effect effects a mixing of the levels (9,8) and (8,6) and by this a reduction of the line (9→8) in comparison to 146 Nd. For this isotope information on the effects of the strong interaction could be extracted separately for the fine structure components. (orig.) [de

  6. Interactions of cosmic ray hadrons from 104 to 106 GeV

    International Nuclear Information System (INIS)

    Gaisser, T.K.

    1977-01-01

    Three topics from the field of high energy cosmic rays that are relevant to properties of hadronic interactions at energies not accessible to existing accelerators are discussed. In each case, the implications for future experiments at ISABELLE and other accelerators planned to probe the energy range of E/sub Lab/ approximately 10 4 GeV and beyond are evaluated. A systematic analysis of inclusive distributions of photons produced in collisions of hadrons with light nuclei is given. The overall conclusion is that, although the data is consistent with scaling for small x in the fragmentation region, the plateau appears to rise significantly beyond ISR energies with a correspondingly rapid increase in multiplicity. The situation in the more controversial field of high p/sub T/ in cosmic rays is summarized. If the suggestions of some experiments are correct, then the high p/sub T/ component of hadronic interactions must become much more important relative to the normal component for E/sub Lab/ > 10 4 GeV than would be expected by extrapolating accelerator data on high p/sub T/ using fits of the form p/sub T/ -8 . Some analyses of atmospheric cascades produced by interactions of cosmic rays of E greater than or equal to 10 6 GeV are briefly reviewed. The interpretation of these experiments is ambiguous because the primary composition of cosmic rays is unknown at these energies. It is, however, possible to draw conclusions corresponding to various assumptions about the primary composition

  7. Developing a Laue Lens for Nuclear Astrophysics: The Challenge of Focusing Soft Gamma-rays

    Science.gov (United States)

    Barriere, Nicolas

    Soft gamma rays provide a unique window on the high-energy Universe, especially for studying nuclear astrophysics through nuclear line emission. However, the sensitivity of state-of-the-art gamma-ray telescopes is severely limited by the intense instrumental background when flown in space. A solution is to decouple the photon collection area from the photon detection area. Focusing source photons from a large collection area onto a small detector volume would dramatically improve the signal-to-noise ratio, and hence provide the long awaited sensitivity leap in this challenging energy band. Laue crystal diffraction can be utilized to focus soft gamma rays when configured in a Laue lens. While this technology has been demonstrated on balloon flights, the type of crystals used and the process of assembling many crystals into a lens have not been optimized yet. We propose to address all the technical aspects of the construction of a scientifically exploitable Laue lens in order to bring this technology to TRL-6. To this end, two small prototypes representative of the diversity of Laue lenses will be built and tested in relevant environments, leveraging the work accomplished under a previous APRA grant. This project will establish the real performances, the cost, and the construction duration of a full-scale lens, allowing us to propose a Laue lens telescope for suborbital or satellite missions.

  8. Statistical methods applied to gamma-ray spectroscopy algorithms in nuclear security missions.

    Science.gov (United States)

    Fagan, Deborah K; Robinson, Sean M; Runkle, Robert C

    2012-10-01

    Gamma-ray spectroscopy is a critical research and development priority to a range of nuclear security missions, specifically the interdiction of special nuclear material involving the detection and identification of gamma-ray sources. We categorize existing methods by the statistical methods on which they rely and identify methods that have yet to be considered. Current methods estimate the effect of counting uncertainty but in many cases do not address larger sources of decision uncertainty, which may be significantly more complex. Thus, significantly improving algorithm performance may require greater coupling between the problem physics that drives data acquisition and statistical methods that analyze such data. Untapped statistical methods, such as Bayes Modeling Averaging and hierarchical and empirical Bayes methods, could reduce decision uncertainty by rigorously and comprehensively incorporating all sources of uncertainty. Application of such methods should further meet the needs of nuclear security missions by improving upon the existing numerical infrastructure for which these analyses have not been conducted. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Measurement of gamma ray flux within the containment building at the first unit of Kori nuclear power station

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T. W.; Kim, K. D.; Yoon, C. H.; Han, J. M.; Hu, Y. H. [Korea Hydraulic and Nuclear Power Company, Taejon (Korea, Republic of)

    2004-07-01

    To evaluate gamma ray dose response of GM counter being used for monitoring of gamma ray field in nuclear power plants, gamma ray energy spectra and fluxes were obtained for three positions at the unit 1 of the Kori nuclear power station. By applying the response values of Eberline's E112B survey meter to the results, the doses represented on the survey meter were overestimated from 1.31 to 1.37 times when compared to the real doses for these three positions.

  10. The quadrupole moment and strong interaction parameters from muonic and pionic X-ray studies of 237Np

    International Nuclear Information System (INIS)

    Laat, C.T.A.M. de; Taal, A.; Duinker, W.; Konijn, J.; Petitjean, C.; Reist, H.W.; Mueller, W.; Commission of the European Communities, Geel

    1987-01-01

    The X-ray spectrum of muonic and pionic 237 Np has been investigated with muons and pions stopped in a NpO 2 target. The nuclear spectroscopic quadrupole moment was determined to be Q=3.886±0.006 b from the splittings of the muonic 5g→4f hyperfine complexes. The B(E2)↓-values for the first and second excited states were evaluated as 3.17±0.08 and 2.77±0.10 e 2 b 2 , respectively. A comparison between the muonic and pionic 5g→4f hyperfine complexes yields the strong interaction parameter for the pionic 4f state. For the first time a change of sign as function of Z for the strong interaction quadrupole shift ε 2 (4f) has been observed. The standard optical model predictions agree reasonably well with the measured strong interaction monopole shift, ε 0 (4f), and width, Γ 0 (4f), while they disagree with the experimental value for ε 2 . A stronger s-wave repulsion in the optical potential could explain this effect. (orig.)

  11. REVEALING TYPE Ia SUPERNOVA PHYSICS WITH COSMIC RATES AND NUCLEAR GAMMA RAYS

    International Nuclear Information System (INIS)

    Horiuchi, Shunsaku; Beacom, John F.

    2010-01-01

    Type Ia supernovae (SNe Ia) remain mysterious despite their central importance in cosmology and their rapidly increasing discovery rate. The progenitors of SNe Ia can be probed by the delay time between progenitor birth and explosion as SNe Ia. The explosions and progenitors of SNe Ia can be probed by MeV nuclear gamma rays emitted in the decays of radioactive nickel and cobalt into iron. We compare the cosmic star formation and SN Ia rates, finding that their different redshift evolution requires a large fraction of SNe Ia to have large delay times. A delay-time distribution of the form t -α with α = 1.0 ± 0.3 provides a good fit, implying that 50% of SNe Ia explode more than ∼1 Gyr after progenitor birth. The extrapolation of the cosmic SN Ia rate to z = 0 agrees with the rate we deduce from catalogs of local SNe Ia. We investigate prospects for gamma-ray telescopes to exploit the facts that escaping gamma rays directly reveal the power source of SNe Ia and uniquely provide tomography of the expanding ejecta. We find large improvements relative to earlier studies by Gehrels et al. in 1987 and Timmes and Woosley in 1997 due to larger and more certain SN Ia rates and advances in gamma-ray detectors. The proposed Advanced Compton Telescope, with a narrow-line sensitivity ∼60 times better than that of current satellites, would, on an annual basis, detect up to ∼100 SNe Ia (3σ) and provide revolutionary model discrimination for SNe Ia within 20 Mpc, with gamma-ray light curves measured with ∼10σ significance daily for ∼100 days. Even more modest improvements in detector sensitivity would open a new and invaluable astronomy with frequent SN Ia gamma-ray detections.

  12. Gamma-ray induced Doppler broadening and the determination of lifetimes of excited nuclear states

    International Nuclear Information System (INIS)

    Boerner, H.G.; Jolie, J.; Robinson, S.J.; Kessler, E.G.; Dewey, S.M.; Greene, G.; Deslattes, R.; Ulbig, S.; Lieb, K.P.; Casten, R.F.; Krusche, B.; Cizewski, J.A.

    1990-01-01

    Measurements of lifetimes of excited states in nuclei yield crucial information for sensitive tests of nuclear models. Here a novel method will be discussed which involves the GRID (Gamma Ray Induced Doppler broadening) technique, in which Doppler broadening is observed in a transition from a nucleus recoiling from the emission of a previous gamma ray. As the recoil energy is extremely small, ultra-high energy resolving power has to be used. To date all such experiments have been carried out at ILL using the GAMS4 double flat crystal spectrometer which is operated in a NIST-ILL collaboration. The method can be used for all lifetimes below a few picoseconds. The wide range of applicability, together with the very exhaustive set of data often obtained, is an advantage with respect to many other methods. The characteristic features of GRID will be discussed using some selected examples. 21 refs., 8 figs

  13. Delayed Gamma-Ray Spectroscopy for Non-Destructive Assay of Nuclear Materials

    Energy Technology Data Exchange (ETDEWEB)

    Ludewigt, Bernhard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mozin, Vladimir [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Campbell, Luke [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Favalli, Andrea [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hunt, Alan W. [Idaho State Univ., Pocatello, ID (United States); Reedy, Edward T. [Idaho State Univ., Pocatello, ID (United States); Seipel, Heather A. [Idaho State Univ., Pocatello, ID (United States)

    2015-06-01

    Modeling capabilities were added to an existing framework and codes were adapted as needed for analyzing experiments and assessing application-specific assay concepts including simulation of measurements over many short irradiation/spectroscopy cycles. The code package was benchmarked against the data collected at the IAC for small targets and assembly-scale data collected at LANL. A study of delayed gamma-ray spectroscopy for nuclear safeguards was performed for a variety of assemblies in the extensive NGSI spent fuel library. The modeling results indicate that delayed gamma-ray responses can be collected from spent fuel assemblies with statistical quality sufficient for analyzing their isotopic composition using a 1011 n/s neutron generator and COTS detector instrumentation.

  14. Estimation of the self-attenuation correction factor for gamma rays emission from nuclear materials

    International Nuclear Information System (INIS)

    Badawy, A.; El-Gammal, W.A.

    2001-01-01

    This work presents an investigation of the self-attenuation of gamma-rays emission from nuclear materials (NMs) for measuring the U-235 enrichment, U-235 mass content and isotopic composition of NMs by non-destructive assay technique [NDA]. The measurements then would not need the use of suitable NM Standards which may not be available in many situations. The self-attenuation correction factor (F) may be estimated by the use of the linear attenuation factor of the assayed sample, the geometrical configuration of the assay set-up and the position of the assayed sample relative to the detector. A developed mathematical analysis makes use of specific parameters which affect the estimation of the self-attenuation of the source-detector system which emits passive gamma-rays at certain prominent signatures

  15. Nuclear charge radii from X-ray transitions in muonic C, O and N

    CERN Document Server

    Dubler, T; Schellenberg, L; Schneuwly, H; Vuilleumier, J L; Walter, H K

    1973-01-01

    Energies of muonic X-rays permit an almost model independent determination of nuclear root mean square (rms) radii for light and medium nuclei, which can be compared to those obtained from elastic electron scattering experiments at low momentum transfer. In the present experiment the X-ray energies of the K series of C, N and O up to the 6p-1s transition are determined with an accuracy of +or-15 eV from which rms radii are deduced comparable in precision to the electron scattering data. Muons from the CERN muon channel were stopped in a target, which contained 70 gr dimethylglyoxim (C/sub 4/H /sub 8/N/sub 2/O/sub 2/) and 18 gr rhodium powder. (0 refs).

  16. Advances in gamma ray resonant scattering and absorption long-lived isomeric nuclear states

    CERN Document Server

    Davydov, Andrey V

    2015-01-01

    This book presents the basics and advanced topics of research of gamma ray physics. It describes measuring of  Fermi surfaces with gamma resonance spectroscopy and the theory of angular distributions of resonantly scattered gamma rays. The dependence of excited-nuclei average lifetime on the shape of the exciting-radiation spectrum and electron binding energies in the spectra of scattered gamma rays is described. Resonant excitation by gamma rays of nuclear isomeric states with long lifetime leads to the emission and absorption lines. In the book, a new gamma spectroscopic method, gravitational gamma spectrometry, is developed. It has a resolution hundred million times higher than the usual Mössbauer spectrometer. Another important topic of this book is resonant scattering of annihilation quanta by nuclei with excited states in connection with positron annihilation. The application of the methods described is to explain the phenomenon of Coulomb fragmentation of gamma-source molecules and resonant scatt...

  17. Design and construction of a Cherenkov imager for charge measurement of nuclear cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Bourrion, O; Bernard, C; Bondoux, D; Bouly, J L; Bouvier, J; Boyer, B; Brinet, M; Buenerd, M; Damieux, G; Derome, L; Eraud, L; Foglio, R; Fombaron, D; Grondin, D; Marton, M; Pelissier, A [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53, rue des Martyrs, Grenoble (France); Lee, M H; Lutz, L [University of Maryland, College Park MD 20742 (United States); Menchaca-Rocha, A [Instituto de Fisica, UNAM, A.P. 20-364, 01000 Mexico DF (Mexico); Perie, J N, E-mail: olivier.bourrion@lpsc.in2p3.fr [Universite de Toulouse, INSA, UPS, Mines Albi, ISAE, ICA (Institut Clement Ader), 133, avenue de Rangueil, F-31077 Toulouse (France)

    2011-06-15

    A proximity focusing Cherenkov imager called CHERCAM, has been built for the charge measurement of nuclear cosmic rays with the CREAM instrument. It consists of a silica aerogel radiator plane across from a detector plane equipped with 1,600 1'' diameter photomultipliers. The two planes are separated by a ring expansion gap. The Cherenkov light yield is proportional to the charge squared of the incident particle. The expected relative light collection accuracy is in the few percents range. It leads to an expected single element separation over the range of nuclear charge Z of main interest 1 {<=} Z{approx}<26. CHERCAM is designed to fly with the CREAM balloon experiment. The design of the instrument and the implemented technical solutions allowing its safe operation in high altitude conditions (radiations, low pressure, cold) are presented.

  18. Design and construction of a Cherenkov imager for charge measurement of nuclear cosmic rays

    International Nuclear Information System (INIS)

    Bourrion, O; Bernard, C; Bondoux, D; Bouly, J L; Bouvier, J; Boyer, B; Brinet, M; Buenerd, M; Damieux, G; Derome, L; Eraud, L; Foglio, R; Fombaron, D; Grondin, D; Marton, M; Pelissier, A; Lee, M H; Lutz, L; Menchaca-Rocha, A; Perie, J N

    2011-01-01

    A proximity focusing Cherenkov imager called CHERCAM, has been built for the charge measurement of nuclear cosmic rays with the CREAM instrument. It consists of a silica aerogel radiator plane across from a detector plane equipped with 1,600 1'' diameter photomultipliers. The two planes are separated by a ring expansion gap. The Cherenkov light yield is proportional to the charge squared of the incident particle. The expected relative light collection accuracy is in the few percents range. It leads to an expected single element separation over the range of nuclear charge Z of main interest 1 ≤ Z∼<26. CHERCAM is designed to fly with the CREAM balloon experiment. The design of the instrument and the implemented technical solutions allowing its safe operation in high altitude conditions (radiations, low pressure, cold) are presented.

  19. Particle induced X-ray emission and complementary nuclear methods for trace element determination; Plenary lecture

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, S A.E. [Lund Univ. (Sweden). Dept. of Nuclear Physics

    1992-03-01

    In this review the state-of-the-art of particle induced X-ray emission (PIXE) methods for the determination of trace elements is described. The developmental work has mostly been carried out in nuclear physics laboratories, where accelerators are available, but now the increased interest has led to the establishment of other dedicated PIXE facilities. The reason for this interest is the versatility, high sensitivity and multi-element capability of PIXE analysis. A further very important advantage is that PIXE can be combined with the microbeam technique, which makes elemental mapping with a spatial resolution of about 1 {mu}m possible. As a technique, PIXE can also be combined with other nuclear reactions such as elastic scattering and particle-induced gamma emission, so that light elements can be determined. The usefulness of PIXE is illustrated by a number of typical applications in biology, medicine, geology, air pollution research, archaeology and the arts. (author).

  20. Nuclear structure and shapes from prompt gamma ray spectroscopy of fission products

    International Nuclear Information System (INIS)

    Ahmad, I.; Morss, L.R.; Durell, J.L.

    1996-01-01

    Many nuclear shape phenomena are predicted to occur in neutron-rich nuclei. The best source for the production of these nuclides is the spontaneous fission which produces practically hundreds of nuclides with yields of greater than 0.1 % per decay. Measurements of coincident gamma rays with large Ge arrays have recently been made to obtain information on nuclear structures and shapes of these neutron- rich nuclei. Among the important results that have been obtained from such measurements are octupole correlations in Ba isotopes, triaxial shapes in Ru nuclei, two-phonon vibrations in 106 Mo and level lifetimes and quadrupole moments in Nd isotopes and A=100 nuclei. These data have been used to test theoretical models

  1. Effects and radiation protection aspects of Gamma-rays in Nuclear Medicine: A review

    International Nuclear Information System (INIS)

    Begum, Ferdousi; Paul, Ashoke Kumar; Miah, Md. Sayedur Rahman; Rahman, Hosne Ara

    2004-01-01

    In Nuclear Medicine Centre of Bangladesh the radioisotope like ''1''3''1I, ''1''2''5I, ''9''9''mTc and ''9''0Sr are mainly used. These isotopes radiate gamma and /or beta rays. Ionizing radiation cannot be sensed or identified without special knowledge and scientific instruments. The radiation, unless properly controlled, causes harm to special type and nature to the patients, worker, public and environment. It causes somatic and genetic effects. (author) 5 tabs., 8 refs

  2. Approximate techniques for calculating gamma ray dose rates in nuclear power plants

    International Nuclear Information System (INIS)

    Lahti, G.P.

    1986-01-01

    Although today's computers have made three-dimensional discrete ordinates transport codes a virtual reality, there is still a need for approximate techniques for estimating radiation environments. This paper discusses techniques for calculating gamma ray dose rates in nuclear power plants where Compton scattering is the dominant attenuation mechanism. The buildup factor method is reviewed; its use and misuse are discussed. Several useful rules-of-thumb are developed. The paper emphasizes the need for understanding the fundamental physics and draws heavily on the old, classic references

  3. Wide Field-of-View Soft X-Ray Imaging for Solar Wind-Magnetosphere Interactions

    Science.gov (United States)

    Walsh, B. M.; Collier, M. R.; Kuntz, K. D.; Porter, F. S.; Sibeck, D. G.; Snowden, S. L.; Carter, J. A.; Collado-Vega, Y.; Connor, H. K.; Cravens, T. E.; hide

    2016-01-01

    Soft X-ray imagers can be used to study the mesoscale and macroscale density structures that occur whenever and wherever the solar wind encounters neutral atoms at comets, the Moon, and both magnetized and unmagnetized planets. Charge exchange between high charge state solar wind ions and exospheric neutrals results in the isotropic emission of soft X-ray photons with energies from 0.1 to 2.0 keV. At Earth, this process occurs primarily within the magnetosheath and cusps. Through providing a global view, wide field-of-view imaging can determine the significance of the various proposed solar wind-magnetosphere interaction mechanisms by evaluating their global extent and occurrence patterns. A summary of wide field-of-view (several to tens of degrees) soft X-ray imaging is provided including slumped micropore microchannel reflectors, simulated images, and recent flight results.

  4. Delayed Gamma-Ray Spectroscopy for Non-Destructive Assay of Nuclear Materials

    International Nuclear Information System (INIS)

    Ludewigt, Bernhard; Mozin, Vladimir; Campbell, Luke; Favalli, Andrea; Hunt, Alan W.; Reedy, Edward T.E.; Seipel, Heather

    2015-01-01

    High-energy, beta-delayed gamma-ray spectroscopy is a potential, non-destructive assay techniques for the independent verification of declared quantities of special nuclear materials at key stages of the fuel cycle and for directly assaying nuclear material inventories for spent fuel handling, interim storage, reprocessing facilities, repository sites, and final disposal. Other potential applications include determination of MOX fuel composition, characterization of nuclear waste packages, and challenges in homeland security and arms control verification. Experimental measurements were performed to evaluate fission fragment yields, to test methods for determining isotopic fractions, and to benchmark the modeling code package. Experimental measurement campaigns were carried out at the IAC using a photo-neutron source and at OSU using a thermal neutron beam from the TRIGA reactor to characterize the emission of high-energy delayed gamma rays from 235 U, 239 Pu, and 241 Pu targets following neutron induced fission. Data were collected for pure and combined targets for several irradiation/spectroscopy cycle times ranging from 10/10 seconds to 15/30 minutes.The delayed gamma-ray signature of 241 Pu, a significant fissile constituent in spent fuel, was measured and compared to 239 Pu. The 241 Pu/ 239 Pu ratios varied between 0.5 and 1.2 for ten prominent lines in the 2700-3600 keV energy range. Such significant differences in relative peak intensities make it possible to determine relative fractions of these isotopes in a mixed sample. A method for determining fission product yields by fitting the energy and time dependence of the delayed gamma-ray emission was developed and demonstrated on a limited 235 U data set. De-convolution methods for determining fissile fractions were developed and tested on the experimental data. The use of high count-rate LaBr 3 detectors was investigated as a potential alternative to HPGe detectors. Modeling capabilities were added to an

  5. Delayed Gamma-Ray Spectroscopy for Non-Destructive Assay of Nuclear Materials

    Energy Technology Data Exchange (ETDEWEB)

    Ludewigt, Bernhard [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mozin, Vladimir [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Campbell, Luke [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Favalli, Andrea [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hunt, Alan W. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Reedy, Edward T.E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Seipel, Heather [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-06-01

    High-­energy, beta-delayed gamma-­ray spectroscopy is a potential, non-­destructive assay techniques for the independent verification of declared quantities of special nuclear materials at key stages of the fuel cycle and for directly assaying nuclear material inventories for spent fuel handling, interim storage, reprocessing facilities, repository sites, and final disposal. Other potential applications include determination of MOX fuel composition, characterization of nuclear waste packages, and challenges in homeland security and arms control verification. Experimental measurements were performed to evaluate fission fragment yields, to test methods for determining isotopic fractions, and to benchmark the modeling code package. Experimental measurement campaigns were carried out at the IAC using a photo-­neutron source and at OSU using a thermal neutron beam from the TRIGA reactor to characterize the emission of high-­energy delayed gamma rays from 235U, 239Pu, and 241Pu targets following neutron induced fission. Data were collected for pure and combined targets for several irradiation/spectroscopy cycle times ranging from 10/10 seconds to 15/30 minutes.The delayed gamma-ray signature of 241Pu, a significant fissile constituent in spent fuel, was measured and compared to 239Pu. The 241Pu/239Pu ratios varied between 0.5 and 1.2 for ten prominent lines in the 2700-­3600 keV energy range. Such significant differences in relative peak intensities make it possible to determine relative fractions of these isotopes in a mixed sample. A method for determining fission product yields by fitting the energy and time dependence of the delayed gamma-­ray emission was developed and demonstrated on a limited 235U data set. De-­convolution methods for determining fissile fractions were developed and tested on the experimental data. The use of high count-­rate LaBr3 detectors

  6. Progress in Gamma Ray Measurement Information Barriers for Nuclear Material Transparency Monitoring

    International Nuclear Information System (INIS)

    Wolford, J.K.; White, G.K.

    2000-01-01

    Negotiations between technical representatives of the US and the Russian Federation in support of several pending nuclear arms and nuclear material control agreements must take account of the need for assurances against the release of sensitive information. Most of these agreements involve storing nuclear material and in some cases nuclear components from stockpile weapons in specially designed containers. Strategies for monitoring the agreements typically include measuring neutron and gamma radiation from the controlled items to verify declared attributes of plutonium or highly enriched uranium. If accurate enough to be useful, these measurements will contain information about the design of the component being monitored, information considered sensitive by one or both parties to the agreement. Safeguards have evolved to prevent disclosure of this information during inspections. These measures combine hardware, software, and procedural measures to contain the sensitive data, presenting only the results needed for verification. Custom features preserve data security and guard against disclosure in case of failure. This paper summarizes the general problem and discusses currently developing solutions for a high resolution gamma ray detection system. It argues for the simplest possible implementation of several key system components

  7. ROLE OF LINE-OF-SIGHT COSMIC-RAY INTERACTIONS IN FORMING THE SPECTRA OF DISTANT BLAZARS IN TeV GAMMA RAYS AND HIGH-ENERGY NEUTRINOS

    International Nuclear Information System (INIS)

    Essey, Warren; Kusenko, Alexander; Kalashev, Oleg; Beacom, John F.

    2011-01-01

    Active galactic nuclei (AGNs) can produce both gamma rays and cosmic rays. The observed high-energy gamma-ray signals from distant blazars may be dominated by secondary gamma rays produced along the line of sight by the interactions of cosmic-ray protons with background photons. This explains the surprisingly low attenuation observed for distant blazars, because the production of secondary gamma rays occurs, on average, much closer to Earth than the distance to the source. Thus, the observed spectrum in the TeV range does not depend on the intrinsic gamma-ray spectrum, while it depends on the output of the source in cosmic rays. We apply this hypothesis to a number of sources and, in every case, we obtain an excellent fit, strengthening the interpretation of the observed spectra as being due to secondary gamma rays. We explore the ramifications of this interpretation for limits on the extragalactic background light and for the production of cosmic rays in AGNs. We also make predictions for the neutrino signals, which can help probe the acceleration of cosmic rays in AGNs.

  8. Molecular interactions of the combined effects of bleomycin and x-rays on mammalian cell survival

    International Nuclear Information System (INIS)

    Byfield, J.E.; Lee, Y.C.; Tu, L.; Kulhanian, F.

    1976-01-01

    The interactions between bleomycin and x-ray damage and repair have been examined in rat and human tumor cells. Bleomycin itself induces extensive DNA single-strand breaks but does not appear to inhibit the repair of x-ray-induced DNA single-strand breaks. Quantitative analysis of these interactions is complicated by the retention of active bleomycin within cells that remains capable of further DNA degradation even under the conditions of alkaline sucrose gradient cell lysis. DNA double-strand breaks and/or disruptions of DNA-lipid complexes also occur following bleomycin exposure. X-ray-induced excision repair replication is only minimally influenced by even high concentrations of bleomycin. A small amount of excision repair is demonstrable in nonirradiated cells treated with high concentrations of bleomycin consistent with repair of bleomycin-induced nucleotide damage in cellular DNA by a ''cut and patch'' repair mechanism. Repair of bleomycin-induced DNA single-strand breaks also occurs. The data indicate that bleomycin and x-ray damage are quite similar both in their induction and repair, but that lesions occur and are repaired independently. The enzymatic mechanisms appear similar in the two cell types despite substantial differences in their sensitivity to bleomycin

  9. Bright ultrashort x-rays from intense subpicosecond laser-plasma interactions

    International Nuclear Information System (INIS)

    Umstadter, D.

    1995-01-01

    Short-pulse, high-intensity lasers interacting with solid targets make possible the study of a new class of laser-plasma interactions. They are unique because during the ultrashort laser pulse relatively little expansion occurs, and the density scale length remains much less than the laser wavelength. This makes possible the direct deposition of a significant amount of the laser energy at close to solid density. Steep plasma temperature and density gradients subsequently cause rapid cooling, resulting in highly non-equilibrium conditions and the concurrent emission of extremely bright ultrashort x-ray pulses. In this study, the latter are investigated experimentally with temporally and spectrally resolved soft x-ray diagnostics. The emitted x-ray spectra from solid targets with various atomic numbers are characterized for a laser pulse width τ l ∼ 400 fs. These ultrashort x rays may be used as (1) a diagnostic of solid-density plasma conditions, (2) a tool for the study of radiation hydrodynamics in a parameter regime that is otherwise inaccessible, and (3) a source for time-resolved diffraction, spectroscopy, or microscopy studies of transient chemical, biological or physical phenomena

  10. Synchrotron X-ray Investigations of Mineral-Microbe-Metal Interactions

    International Nuclear Information System (INIS)

    Kemner, Kenneth M.; O'Loughlin, Edward J.; Kelly, Shelly D.; Boyanov, Maxim I.

    2005-01-01

    Interactions between microbes and minerals can play an important role in metal transformations (i.e. changes to an element's valence state, coordination chemistry, or both), which can ultimately affect that element's mobility. Mineralogy affects microbial metabolism and ecology in a system; microbes, in turn, can affect the system's mineralogy. Increasingly, synchrotron-based X-ray experiments are in routine use for determining an element's valence state and coordination chemistry, as well as for examining the role of microbes in metal transformations.

  11. Charge exchange signatures in x-ray line emission accompanying plasma-wall interaction

    Czech Academy of Sciences Publication Activity Database

    Renner, Oldřich; Dalimier, E.; Liska, R.; Oks, E.; Šmíd, Michal

    2012-01-01

    Roč. 397, č. 1 (2012), s. 1-6 ISSN 1742-6588 R&D Projects: GA ČR GAP205/10/0814; GA ČR GAP208/10/2302; GA AV ČR IAAX00100903 Institutional research plan: CEZ:AV0Z10100523 Keywords : laser-produced plasma * particle jets generation * plasma-wall interaction * x-ray spectroscopy * charge exchange Subject RIV: BL - Plasma and Gas Discharge Physics

  12. Velocity gradient induced line splitting in x-ray emission accompanying plasma-wall interaction

    Czech Academy of Sciences Publication Activity Database

    Šmíd, Michal; Renner, Oldřich; Liska, R.

    2013-01-01

    Roč. 125, Aug (2013), s. 38-44 ISSN 0022-4073 R&D Projects: GA ČR GAP205/10/0814; GA ČR GAP205/11/0571 Institutional support: RVO:68378271 Keywords : laser-produced plasmas * x-ray spectroscopy * plasma-wall interaction * spectral line profiles * Doppler shift * ion velocity gradients Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.288, year: 2013

  13. Monte Carlo calculation of the total probability for gamma-Ray interaction in toluene

    International Nuclear Information System (INIS)

    Grau Malonda, A.; Garcia-Torano, E.

    1983-01-01

    Interaction and absorption probabilities for gamma-rays with energies between 1 and 1000 KeV have been computed and tabulated. Toluene based scintillator solution has been assumed in the computation. Both, point sources and homogeneously dispersed radioactive material have been assumed. These tables may be applied to cylinders with radii between 1.25 cm and 0.25 cm and heights between 4.07 cm and 0.20 cm. (Author) 26 refs

  14. X-ray comb generation from nuclear-resonance-stabilized x-ray free-electron laser oscillator for fundamental physics and precision metrology

    Directory of Open Access Journals (Sweden)

    B. W. Adams

    2015-03-01

    Full Text Available An x-ray free-electron laser oscillator (XFELO is a next-generation x-ray source, similar to free-electron laser oscillators at VUV and longer wavelengths but using crystals as high-reflectivity x-ray mirrors. Each output pulse from an XFELO is fully coherent with high spectral purity. The temporal coherence length can further be increased drastically, from picoseconds to microseconds or even longer, by phase-locking successive XFELO output pulses, using the narrow nuclear resonance lines of nuclei such as ^{57}Fe as a reference. We show that the phase fluctuation due to the seismic activities is controllable and that due to spontaneous emission is small. The fluctuation of electron-bunch spacing contributes mainly to the envelope fluctuation but not to the phase fluctuation. By counting the number of standing-wave maxima formed by the output of the nuclear-resonance-stabilized (NRS XFELO over an optically known length, the wavelength of the nuclear resonance can be accurately measured, possibly leading to a new length or frequency standard at x-ray wavelengths. A NRS-XFELO will be an ideal source for experimental x-ray quantum optics as well as other fundamental physics. The technique can be refined for other, narrower resonances such as ^{181}Ta or ^{45}Sc.

  15. Interaction of the IAEA and the United States in controlling nuclear weapons proliferation

    International Nuclear Information System (INIS)

    Tape, G.F.

    1977-01-01

    The emphasis of this paper is on those aspects of the U. S.-IAEA interactions that pertain to the control and assurance of non-diversion of special nuclear materials. Some background information on the IAEA is given

  16. Interaction of Proliferating Cell Nuclear Antigen With DNA at the Single Molecule Level

    KAUST Repository

    Raducanu, Vlad-Stefan

    2016-01-01

    Proliferating cell nuclear antigen (PCNA) is a key factor involved in Eukaryotic DNA replication and repair, as well as other cellular pathways. Its importance comes mainly from two aspects: the large numbers of interacting partners

  17. Novel nuclear-cytoplasmic interaction in wheat (Triticum aestivum) induces vigorous plants

    Science.gov (United States)

    Interspecific hybridization can be considered an accelerator of evolution, otherwise a slow process, solely dependent on mutation and recombination. Upon interspecific hybridization, several novel interactions between nuclear and cytoplasmic genomes emerge which provide additional sources of diversi...

  18. Antiferromagnetism of nuclear matter in the model with effective Gogny interaction

    International Nuclear Information System (INIS)

    Isayev, A.A.; Yang, J.

    2006-01-01

    The possibility of ferromagnetic (FM) antiferromagnetic (AFM) phase transitions in symmetric nuclear matter is analyzed within the framework of a Fermi-liquid theory with the effective Gogny interaction. It is shown that at some critical density nuclear matter undergoes a phase transition to the AFM spin state. The self-consistent equations of spin-polarized nuclear matter have no solutions corresponding to FM spin ordering and, hence, the FM transition does not appear. The AFM spin state properties are investigated [ru

  19. Nuclear matter properties using different sets of parameters in the Gogny interaction

    International Nuclear Information System (INIS)

    Ramadan, Kh.A.; Mansour, H.M.M.

    2002-01-01

    In the present work we use the finite range density dependent effective Gogny interaction to study the equation of state of polarized nuclear matter. Six sets of the interaction parameters are used and a comparison is made with the calculations of Friedman and Pandharipande using a realistic interaction. One of the parameter sets (D1) gives similar results for the properties of polarized nuclear matter while the other parameter sets (D1S, D250, D260, D280 and D300) yield results which are reasonably comparable with the realistic interaction calculation of Friedman and Pandharipande. (author)

  20. Microscopy based studies on the interaction of bio-based silver nanoparticles with Bombyx mori Nuclear Polyhedrosis virus.

    Science.gov (United States)

    Tamilselvan, Selvaraj; Ashokkumar, Thirunavukkarasu; Govindaraju, Kasivelu

    2017-04-01

    In the present investigation, silver nanoparticles (AgNPs) interactions with Bombyx mori Nuclear Polyhedrosis virus (BmNPV) were characterized using High-Resolution Scanning Electron Microscopy (HR-SEM), Energy Dispersive X-ray Analysis (EDAX), Transmission Electron Microscopy (TEM), Atomic Force Microcopy (AFM) and Confocal Microscope (CM). HR-SEM study reveals that the biosynthesized AgNPs have interacted with BmNPV and were found on the surface. TEM micrographs of normal and viral polyhedra treated with AgNPs showed that the nanoparticles were accumulated in the membrane and it was noted that some of the AgNPs successfully penetrated the membrane by reaching the capsid of BmNPV. AFM and confocal microscopy studies reveal that the disruption in the shell membrane tends to lose its stability due to exposure of AgNPs to BmNPV. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. X-ray computed tomography uncovers root-root interactions: quantifying spatial relationships between interacting root systems in three dimensions.

    Science.gov (United States)

    Paya, Alexander M; Silverberg, Jesse L; Padgett, Jennifer; Bauerle, Taryn L

    2015-01-01

    Research in the field of plant biology has recently demonstrated that inter- and intra-specific interactions belowground can dramatically alter root growth. Our aim was to answer questions related to the effect of inter- vs. intra-specific interactions on the growth and utilization of undisturbed space by fine roots within three dimensions (3D) using micro X-ray computed tomography. To achieve this, Populus tremuloides (quaking aspen) and Picea mariana (black spruce) seedlings were planted into containers as either solitary individuals, or inter-/intra-specific pairs, allowed to grow for 2 months, and 3D metrics developed in order to quantify their use of belowground space. In both aspen and spruce, inter-specific root interactions produced a shift in the vertical distribution of the root system volume, and deepened the average position of root tips when compared to intra-specifically growing seedlings. Inter-specific interactions also increased the minimum distance between root tips belonging to the same root system. There was no effect of belowground interactions on the radial distribution of roots, or the directionality of lateral root growth for either species. In conclusion, we found that significant differences were observed more often when comparing controls (solitary individuals) and paired seedlings (inter- or intra-specific), than when comparing inter- and intra-specifically growing seedlings. This would indicate that competition between neighboring seedlings was more responsible for shifting fine root growth in both species than was neighbor identity. However, significant inter- vs. intra-specific differences were observed, which further emphasizes the importance of biological interactions in competition studies.

  2. DARC: Mapping Surface Topography by Ray-Casting for Effective Virtual Screening at Protein Interaction Sites.

    Science.gov (United States)

    Gowthaman, Ragul; Miller, Sven A; Rogers, Steven; Khowsathit, Jittasak; Lan, Lan; Bai, Nan; Johnson, David K; Liu, Chunjing; Xu, Liang; Anbanandam, Asokan; Aubé, Jeffrey; Roy, Anuradha; Karanicolas, John

    2016-05-12

    Protein-protein interactions represent an exciting and challenging target class for therapeutic intervention using small molecules. Protein interaction sites are often devoid of the deep surface pockets presented by "traditional" drug targets, and crystal structures reveal that inhibitors typically engage these sites using very shallow binding modes. As a consequence, modern virtual screening tools developed to identify inhibitors of traditional drug targets do not perform as well when they are instead deployed at protein interaction sites. To address the need for novel inhibitors of important protein interactions, here we introduce an alternate docking strategy specifically designed for this regime. Our method, termed DARC (Docking Approach using Ray-Casting), matches the topography of a surface pocket "observed" from within the protein to the topography "observed" when viewing a potential ligand from the same vantage point. We applied DARC to carry out a virtual screen against the protein interaction site of human antiapoptotic protein Mcl-1 and found that four of the top-scoring 21 compounds showed clear inhibition in a biochemical assay. The Ki values for these compounds ranged from 1.2 to 21 μM, and each had ligand efficiency comparable to promising small-molecule inhibitors of other protein-protein interactions. These hit compounds do not resemble the natural (protein) binding partner of Mcl-1, nor do they resemble any known inhibitors of Mcl-1. Our results thus demonstrate the utility of DARC for identifying novel inhibitors of protein-protein interactions.

  3. Radioisotope identification method for poorly resolved gamma-ray spectrum of nuclear security concern

    International Nuclear Information System (INIS)

    Ninh, Giang Nguyen; Phongphaeth, Pengvanich; Nares, Chankow; Hao, Quang Nguyen

    2016-01-01

    Gamma-ray signal can be used as a fingerprint for radioisotope identification. In the context of radioactive and nuclear materials security at the border control point, the detection task can present a significant challenge due to various constraints such as the limited measurement time, the shielding conditions, and the noise interference. This study proposes a novel method to identify the signal of one or several radioisotopes from a poorly resolved gamma-ray spectrum. In this method, the noise component in the raw spectrum is reduced by the wavelet decomposition approach, and the removal of the continuum background is performed using the baseline determination algorithm. Finally, the identification of radioisotope is completed using the matrix linear regression method. The proposed method has been verified by experiments using the poorly resolved gamma-ray signals from various scenarios including single source, mixing of natural uranium with five of the most common industrial radioactive sources (57Co, 60Co, 133Ba, 137Cs, and 241Am). The preliminary results show that the proposed algorithm is comparable with the commercial method

  4. Radioisotope identification method for poorly resolved gamma-ray spectrum of nuclear security concern

    Energy Technology Data Exchange (ETDEWEB)

    Ninh, Giang Nguyen; Phongphaeth, Pengvanich, E-mail: phongphaeth.p@chula.ac.th; Nares, Chankow [Nuclear Engineering Department, Faculty of Engineering, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330 (Thailand); Hao, Quang Nguyen [Vietnam Atomic Energy Institute, Ministry of Science and Technology, Hanoi (Viet Nam)

    2016-01-22

    Gamma-ray signal can be used as a fingerprint for radioisotope identification. In the context of radioactive and nuclear materials security at the border control point, the detection task can present a significant challenge due to various constraints such as the limited measurement time, the shielding conditions, and the noise interference. This study proposes a novel method to identify the signal of one or several radioisotopes from a poorly resolved gamma-ray spectrum. In this method, the noise component in the raw spectrum is reduced by the wavelet decomposition approach, and the removal of the continuum background is performed using the baseline determination algorithm. Finally, the identification of radioisotope is completed using the matrix linear regression method. The proposed method has been verified by experiments using the poorly resolved gamma-ray signals from various scenarios including single source, mixing of natural uranium with five of the most common industrial radioactive sources (57Co, 60Co, 133Ba, 137Cs, and 241Am). The preliminary results show that the proposed algorithm is comparable with the commercial method.

  5. Systematics of gamma-ray energy spectra for classification of workplaces around a nuclear facility

    International Nuclear Information System (INIS)

    Urabe, Itsumasa; Tsujimoto, Tadashi; Katsurayama, Kousuke

    1988-01-01

    Radiation dosimetry in workplaces has been carried out both for assurance of the doses complying with the acceptable values and for improvement of protection methods to minimise detriments of the exposed population. This means that it is very important not only to determine dosimetric quantities in workplaces but also to know features of radiation levels because information for radiation protection can often be derived from the radiometric quantities. Classification of workplaces based on the feature of gamma-ray energy spectra is one of the practical ways to realise radiation protection being taken into consideration of the radiometric quantities. Furthermore, demarcation of workplaces based on these radiometric quantities may be effective for improvement of radiation protection practice such as estimation of radiation doses, designing of radiation shields and other activities. From these points of view, gamma-ray energy spectra have been determined in various workplaces in nuclear facilities, and systematics of gamma-ray fields were tried for classification of workplaces on the basis of the feature appeared in health physical quantities such as effective dose equivalents and responses of dosemeters

  6. Wavelength Dispersive X-ray Fluorescence Analysis of Actinides in Dissolved Nuclear Fuels

    Energy Technology Data Exchange (ETDEWEB)

    O' Hara, David [Parallax Research, Inc., Tallahassee, FL (United States)

    2015-10-15

    There is an urgent need for an instrument that can quickly measure the concentration of Plutonium and other Actinides mixed with Uranium in liquids containing dissolved spent fuel rods. Parallax Research, Inc. proposes to develop an x-ray spectrometer capable of measuring U, Np and Pu in dissolved nuclear fuel rod material to less than 10 ppm levels to aid in material process control for these nuclear materials. Due to system noise produced by high radioactivity, previous x-ray spectrometers were not capable of low level measurements but the system Parallax proposed has no direct path for undesired radiation to get to the detector and the detector in the proposed device is well shielded from scatter and has very low dark current. In addition, the proposed spectrometer could measure these three elements simultaneously, also measuring background positions with an energy resolution of roughly 100 eV making it possible to see a small amount of Pu that would be hidden under the tail of the U peak in energy dispersive spectrometers. Another nearly identical spectrometer could be used to target Am and Cm if necessary. The proposed spectrometer needs only a tiny sample of roughly 1 micro-liter (1 mm3) and the measurement can be done with the liquid flowing in a radiation and chemical immune quartz capillary protected by a stainless steel rod making it possible to continuously monitor the liquid or to use a capillary manifold to measure other liquid streams. Unlike other methods such as mass spectroscopy where the sample must be taken to a remote facility and might take days for turn-around, the proposed measurement should take less than an hour. This spectrometer could enable near real-time measurement of U, Pu and Np in dilute dissolved spent nuclear fuel rod streams.

  7. The role of non-specific interactions in nuclear organization

    NARCIS (Netherlands)

    Nooijer, de S.

    2010-01-01

    The most important organelle in eukaryotic cells is the nucleus. Many processes occurring within the nucleus depend on spatial organization of the nucleus. The spatial organization of the eukaryotic nucleus derives from interactions between its constituents. Both specific interactions, for instance

  8. Heterogeneous nuclear ribonucleoprotein D/AUF1 interacts with ...

    Indian Academy of Sciences (India)

    SEARCHU

    Ribonucleic acids (RNAs) in cells are bound to proteins. Heterogeneous nuclear ribonucleoprotein (hnRNP) is one of the representative proteins bound to RNAs in eukaryotic cells. More than 30 hnRNPs have been determined to exist in human nuclei, and are referred to as hnRNPs A1 through U (Choi and Dreyfuss 1984; ...

  9. [Electroweak and other interactions in medium-energy nuclear physics

    International Nuclear Information System (INIS)

    Mukhopadhyay, N.C.

    1993-01-01

    This report discusses the following topics: spectrum generating algebra; vibrational spectra in the heavy quarkonia; chiral soliton model; pion neutral photoproduction from proton with polarized photons in the delta-1232 region; compton scattering in the delta- 1232 region; nucleon magnetic polarizability and the role of the delta resonance; eta photo- and electroproduction; perturbative QCD; and nuclear muon capture

  10. Alpha Particles and X Rays Interact in Inducing DNA Damage in U2OS Cells.

    Science.gov (United States)

    Sollazzo, Alice; Brzozowska, Beata; Cheng, Lei; Lundholm, Lovisa; Haghdoost, Siamak; Scherthan, Harry; Wojcik, Andrzej

    2017-10-01

    Survivors of the atomic bombings of Hiroshima and Nagasaki are monitored for health effects within the Life Span Study (LSS). The LSS results represent the most important source of data about cancer effects from ionizing radiation exposure, which forms the foundation for the radiation protection system. One uncertainty connected to deriving universal risk factors from these results is related to the problem of mixed radiation qualities. The A-bomb explosions generated a mixed beam of the sparsely ionizing gamma radiation and densely ionizing neutrons. However, until now the possible interaction of the two radiation types of inducing biological effects has not been taken into consideration. The existence of such interaction would suggest that the application of risk factors derived from the LSS to predict cancer effects after pure gamma-ray irradiation (such as in the Fukushima prefecture) leads to an overestimation of risk. To analyze the possible interaction of radiation types, a mixed-beam exposure facility was constructed where cells can be exposed to sparsely ionizing X rays and densely ionizing alpha particles. U2OS cells were used, which are stably transfected with a plasmid coding for the DNA repair gene 53BP1 coupled to a gene coding for the green fluorescent protein (GFP). The induction and repair of DNA damage, which are known to be related to cancer induction, were analyzed. The results suggest that alpha particles and X rays interact, leading to cellular and possibly cancer effects, which cannot be accurately predicted based on assuming simple additivity of the individual mixed-beam components.

  11. Nuclear fuel rod with burnable plate and pellet-clad interaction fix

    International Nuclear Information System (INIS)

    Boyle, R.F.

    1987-01-01

    This patent describes a nuclear fuel rod comprising a metallic tubular cladding containing nuclear fuel pellets, the pellets containing enriched uranium-235. The improvement described here comprises: ceramic wafers, each wafter comprising a sintered mixture of gadolinium oxide and uranium dioxide, the uranium oxide having no more uranium-235 than is present in natural uranium dioxide. Each of the wafers is axially disposed between a major portion of adjacent the nuclear fuel pellets, whereby the wafers freeze out volatile fission products produced by the nuclear fuel and prevent interaction of the fission products with the metallic tubing cladding

  12. Interaction of x-rays and food pyrolysis products in producing oncogenic transformation in vitro

    International Nuclear Information System (INIS)

    Borek, C.; Ong, A.

    1981-01-01

    In recent years it has become evident from epidemiological and experimental data that a large number of environmental factors, including diet, play a role in modifying the incidence of cancer. Cell culture systems in which oncogenic transformation serves as an end point are powerful tools for evaluating these questions. Using such systems it has been shown recently that pyrolysis products from charred surfaces of broiled meat and fish can transform hamster embryo cells in vitro as well as produce tumors in the animal. Our studies in vitro have demonstrated the oncogenic potential of ionizing radiation in both hamster and human cells and have established in hamster cells the dose response relationship at doses ranging from 1 to 600 rad for x-rays and 0.1 to 150 rad for neutrons. The present work was aimed at evaluating whether there exists a cocarcinogenic interaction between a pyrolysis product and x-rays in their ability to transform hamster embryo cells in vitro. We have found that when cells are exposed to x-rays prior to treatment with the pyrolysis product there appears to be a synergistic interaction between the two agents in their ability to transform the cells

  13. Crystallization and X-ray diffraction studies of crustacean proliferating cell nuclear antigen

    International Nuclear Information System (INIS)

    Carrasco-Miranda, Jesus S.; Cardona-Felix, Cesar S.; Lopez-Zavala, Alonso A.; Re Vega, Enrique de la; De la Mora, Eugenio; Rudiño-Piñera, Enrique; Sotelo-Mundo, Rogerio R.; Brieba, Luis G.

    2012-01-01

    Proliferating cell nuclear antigen from Litopenaeus vannamei was recombinantly expressed, purified and crystallized. Diffraction data were obtained and processed to 3 Å. Proliferating cell nuclear antigen (PCNA), a member of the sliding clamp family of proteins, interacts specifically with DNA replication and repair proteins through a small peptide motif called the PCNA-interacting protein or PIP box. PCNA is recognized as one of the key proteins involved in DNA metabolism. In the present study, the recombinant PCNA from Litopenaeus vannamei (LvPCNA) was heterologously overexpressed and purified using metal ion-affinity chromatography. Crystals suitable for diffraction grew overnight using the hanging-drop vapour-diffusion method. LvPCNA crystals belong to space group C2 with unit-cell parameters a = 144.6, b = 83.4, c = 74.3 Å, β = 117.6°. One data set was processed to 3 Å resolution, with an overall R meas of 0.09 and a completeness of 93.3%. Initial phases were obtained by molecular replacement using a homology model of LvPCNA as the search model. Refinement and structural analysis are underway. This report is the first successful crystallographic analysis of a marine crustacean decapod shrimp (L. vannamei) proliferating cell nuclear antigen

  14. Jaw1/LRMP has a role in maintaining nuclear shape via interaction with SUN proteins.

    Science.gov (United States)

    Kozono, Takuma; Tadahira, Kazuko; Okumura, Wataru; Itai, Nao; Tamura-Nakano, Miwa; Dohi, Taeko; Tonozuka, Takashi; Nishikawa, Atsushi

    2018-06-06

    Jaw1/LRMP is characterized as a type II integral membrane protein that is localized to endoplasmic reticulum (ER), however, its physiological functions have been poorly understood. An alignment of amino acid sequence of Jaw1 with KASH proteins, outer nuclear membrane proteins, revealed that Jaw1 has a partial homology to the KASH domain. Here, we show that the function of Jaw1 is to maintain nuclear shape in mouse melanoma cell line. The siRNA-mediated knockdown of Jaw1 caused a severe defect in nuclear shape, and the defect was rescued by ectopic expression of siRNA-resistant Jaw1. Since co-immunoprecipitation assay indicates that Jaw1 interacts with SUN proteins that are inner nuclear proteins and microtubules, this study suggests that Jaw1 has a role in maintaining nuclear shape via interactions with SUN proteins and microtubules.

  15. X-RAY ABSORPTION, NUCLEAR INFRARED EMISSION, AND DUST COVERING FACTORS OF AGNs: TESTING UNIFICATION SCHEMES

    Energy Technology Data Exchange (ETDEWEB)

    Mateos, S.; Carrera, F. J.; Alonso-Herrero, A.; Hernán-Caballero, A.; Barcons, X. [Instituto de Física de Cantabria (CSIC-Universidad de Cantabria), E-39005, Santander (Spain); Ramos, A. Asensio; Almeida, C. Ramos [Instituto de Astrofísica de Canarias, E-38205, La Laguna, Tenerife (Spain); Watson, M. G.; Blain, A. [Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Caccianiga, A.; Ballo, L. [INAF-Osservatorio Astronomico di Brera, via Brera 28, I-20121 Milano (Italy); Braito, V., E-mail: mateos@ifca.unican.es [INAF-Osservatorio Astronomico di Brera, Via Bianchi 46, I-23807 Merate (Italy)

    2016-03-10

    We present the distributions of the geometrical covering factors of the dusty tori (f{sub 2}) of active galactic nuclei (AGNs) using an X-ray selected complete sample of 227 AGNs drawn from the Bright Ultra-hard XMM-Newton Survey. The AGNs have z from 0.05 to 1.7, 2–10 keV luminosities between 10{sup 42} and 10{sup 46} erg s{sup −1}, and Compton-thin X-ray absorption. Employing data from UKIDSS, 2MASS, and the Wide-field Infrared Survey Explorer in a previous work, we determined the rest-frame 1–20 μm continuum emission from the torus, which we model here with the clumpy torus models of Nenkova et al. Optically classified type 1 and type 2 AGNs are intrinsically different, with type 2 AGNs having, on average, tori with higher f{sub 2} than type 1 AGNs. Nevertheless, ∼20% of type 1 AGNs have tori with large covering factors, while ∼23%–28% of type 2 AGNs have tori with small covering factors. Low f{sub 2} are preferred at high AGN luminosities, as postulated by simple receding torus models, although for type 2 AGNs the effect is certainly small. f{sub 2} increases with the X-ray column density, which implies that dust extinction and X-ray absorption take place in material that share an overall geometry and most likely belong to the same structure, the putative torus. Based on our results, the viewing angle, AGN luminosity, and also f{sub 2} determine the optical appearance of an AGN and control the shape of the rest-frame ∼1–20 μm nuclear continuum emission. Thus, the torus geometrical covering factor is a key ingredient of unification schemes.

  16. Experimental study of nuclear models. I. Decay schemes and nuclear reactions. II. Muonic x-ray studies. Progress report, October 1, 1974--September 30, 1975

    International Nuclear Information System (INIS)

    Sheline, R.K.

    1975-01-01

    Progress on the research on our AT-(40-1)-2434 Contract is summarized for the twelve month contract year beginning October 1, 1974, and ending September 30, 1975. The main emphasis of our research continues to be an experimental study of nuclear models. Some change of emphasis is occurring. In the past, the emphasis has been overwhelmingly nuclear reaction spectroscopy and comparison with theoretical models. This year an increasing percentage of the emphasis (perhaps 25 percent) is on the study of nuclear structure from the view point of muonic x-ray spectroscopy. A list of publications is included. (U.S.)

  17. On the systematic behaviour of the intermittency-induces in nuclear interactions

    International Nuclear Information System (INIS)

    Adamovich, M.I.; Aggarwal, M.M.; Alexandrov, Y.A.; Andreeva, N.P.; Anson, Z.V.; Arora, R.; Avetyan, F.A.; Badyal, S.K.; Basova, E.; Bhalla, K.B.; Bhasin, A.; Bhatia, V.S.; Bogdanov, V.G.; Bubnov, V.I.; Burnett, T.H.; Cai, X.; Chasnikov, I.Y.; Chernova, L.P.; Chernyavski, M.M.; Dressel, B.; Eligbaeva, G.Z.; Eremenko, L.E.; Friedlander, E.M.; Gaitinov, A.S.; Ganssauge, E.R.; Garpman, S.; Gerassimov, S.G.; Grote, J.; Gulamov, K.G.; Gupta, S.K.; Gupta, V.; Heckman, H.H.; Huang, H.; Jakobsson, B.; Judek, B.; Kachroo, S.; Kadyrov, F.G.; Kalyachkina, G.S.; Kanygina, E.K.; Karabova, M.; Kaul, G.L.; Kaur, M.; Kharlamov, S.P.; Koss, T.; Krasnov, S.A.; Kumar, V.; Lal, P.; Larionova, V.G.; Lepetan, V.N.; Lindstrom, P.J.; Liu, L.S.; Lokanathan, S.; Lord, J.; Lukicheva, N.S.; Luo, S.B.; Mangotra, L.K.; Marutyan, N.A.; Maslennikova, N.V.; Mittra, I.S.; Mookerjee, S.; Mueller, C.; Nasrulaeva, H.; Nasyrov, S.H.; Navotny, V.S.; Orlova, G.I.; Otterlund, I.; Palsania, H.S.; Peresadko, N.G.; Petrov, N.V.; Plyushchev, V.A.; Qian, W.Y.; Raniwala, R.; Raniwala, S.; Rao, N.K.; Rappoport, V.M.; Rhee, J.T.; Saidkhanov, N.; Salmanova, N.A.; Sarkisova, L.G.; Sarkisyan, V.R.; Schulz, W.; Shabratova, G.S.; Shakhova, T.I.; Singh, B.; Skelding, D.; Soederstroem, K.; Solovjeva, Z.I.; Stenlund, E.; Strausz, S.C.; Sun, J.F.; Svechnikova, L.N.; Tolstov, K.D.; Tretyakova, M.I.; Trofimova, T.P.; Tuleeva, U.; Vokal, S.; Wang, H.Q.; Weng, Z.Q.; Wilkes, R.J.; Xu, G.F.; Zhang, D.H.; Zheng, P.Y.; Zhochova, S.I.; Zhou, D.C.; Zhou, J.C.

    1991-01-01

    The non-statistical fluctuations observed in nuclear interactions, as described by the intermittency-indices from scaled factorial moment analyses, are found to follow a systematic behaviour. The heaviest systems studied, i.e. interactions with sulfur projectiles, are found to have fluctuations which are larger than expected from simple scaling rules. (orig.)

  18. Effects of isospin and momentum dependent interactions on thermal properties of asymmetric nuclear matter

    International Nuclear Information System (INIS)

    Xu Jun; Ma Hongru; Chen Liewen; Li Baoan

    2008-01-01

    Thermal properties of asymmetric nuclear matter are studied within a self-consistent thermal model using an isospin and momentum-dependent interaction (MDI) constrained by the isospin diffusion data in heavy-ion collisions, a momentum-independent interaction (MID), and an isoscalar momentum-dependent interaction (eMDYI). In particular, we study the temperature dependence of the isospin-dependent bulk and single-particle properties, the mechanical and chemical instabilities, and liquid-gas phase transition in hot asymmetric nuclear matter. Our results indicate that the temperature dependence of the equation of state and the symmetry energy are not so sensitive to the momentum dependence of the interaction. The symmetry energy at fixed density is found to generally decrease with temperature and for the MDI interaction the decrement is essentially due to the potential part. It is further shown that only the low momentum part of the single-particle potential and the nucleon effective mass increases significantly with temperature for the momentum-dependent interactions. For the MDI interaction, the low momentum part of the symmetry potential is significantly reduced with increasing temperature. For the mechanical and chemical instabilities as well as the liquid-gas phase transition in hot asymmetric nuclear matter, our results indicate that the boundaries of these instabilities and the phase-coexistence region generally shrink with increasing temperature and are sensitive to the density dependence of the symmetry energy and the isospin and momentum dependence of the nuclear interaction, especially at higher temperatures

  19. On the systematic behaviour of the intermittency-induces in nuclear interactions

    Energy Technology Data Exchange (ETDEWEB)

    Adamovich, M I; Aggarwal, M M; Alexandrov, Y A; Andreeva, N P; Anson, Z V; Arora, R; Avetyan, F A; Badyal, S K; Basova, E; Bhalla, K B; Bhasin, A; Bhatia, V S; Bogdanov, V G; Bubnov, V I; Burnett, T H; Cai, X; Chasnikov, I Y; Chernova, L P; Chernyavski, M M; Dressel, B; Eligbaeva, G Z; Eremenko, L E; Friedlander, E M; Gaitinov, A S; Ganssauge, E R; Garpman, S; Gerassimov, S G; Grote, J; Gulamov, K G; Gupta, S K; Gupta, V; Heckman, H H; Huang, H; Jakobsson, B; Judek, B; Kachroo, S; Kadyrov, F G; Kalyachkina, G S; Kanygina, E K; Karabova, M; Kaul, G L; Kaur, M; Kharlamov, S P; Koss, T; Krasnov, S A; Kumar, V; Lal, P; Larionova, V G; Lepetan, V N; Lindstrom, P J; Liu, L S; Lokanathan, S; Lord, J; Lukicheva, N S; Luo, S B; Mangotra, L K; Marutyan, N A; Maslennikova, N V; Mittra, I S; Mookerjee, S; Mueller, C; Nasrulaeva, H; Nasyrov, S H; Navotny, V S; Orlova, G I; Otterlund, I; Palsania, H S; Peresadko, N G; Petrov, N V; EMU01 Collaboration

    1991-07-18

    The non-statistical fluctuations observed in nuclear interactions, as described by the intermittency-indices from scaled factorial moment analyses, are found to follow a systematic behaviour. The heaviest systems studied, i.e. interactions with sulfur projectiles, are found to have fluctuations which are larger than expected from simple scaling rules. (orig.).

  20. Nuclear interaction potential in a folded-Yukawa model with diffuse densities

    International Nuclear Information System (INIS)

    Randrup, J.

    1975-09-01

    The folded-Yukawa model for the nuclear interaction potential is generalized to diffuse density distributions which are generated by folding a Yukawa function into sharp generating distributions. The effect of a finite density diffuseness or of a finite interaction range is studied. The Proximity Formula corresponding to the generalized model is derived and numerical comparison is made with the exact results. (8 figures)

  1. Calculation of nuclear moment of inertia with proper treatment of pairing interaction

    International Nuclear Information System (INIS)

    Tazaki, S.; Ando, Y.; Hasegawa, M.

    1997-01-01

    An attempt to calculate nuclear moments of inertia treating the pairing interaction exactly is reported. As usual, hamiltonian is composed of the Nilsson's singleparticle energies and the pairing interaction, but the eigenstates and the eigenvalues are calculated exactly in a realistic, sufficiently large model space. The method of calculating the moment of inertia is presented. (author)

  2. Interaction between adrenaline and dibenzo-18-crown-6: Electrochemical, nuclear magnetic resonance, and theoretical study

    Science.gov (United States)

    Yu, Zhang-Yu; Liu, Tao; Wang, Xue-Liang

    2014-12-01

    The interaction between adrenaline (Ad) and dibenzo-18-crown-6 (DB18C6) was studied by cyclic voltammetry, nuclear magnetic resonance spectroscopy, and the theoretical calculations, respectively. The results show that DB18C6 will affect the electron transfer properties of Ad. DB18C6 can form stable supramolecular complexes with Ad through ion-dipole and hydrogen bond interactions.

  3. Tensor quasiparticle interaction and spin-isospin sound in nuclear matter

    International Nuclear Information System (INIS)

    Haensel, P.

    1979-01-01

    The effect of the tensor components of the quasiparticle interaction in nuclear matter on the spin-isospin sound type excitations is studied. Numerical results are obtained using a simplified model of the quasiparticle interaction in nuclear matter. The quasiparticle distribution matrix corresponding to the spin-isospin sound is found to be qualitatively different from that obtained for purely central quasiparticle interaction. The macroscopic effects, however, are restricted to a small change in the phase velocity of the spin-isospin sound. (Auth.)

  4. Interaction Profiling Identifies the Human Nuclear Exosome Targeting Complex

    DEFF Research Database (Denmark)

    Lubas, Michal Szymon; Christensen, Marianne Skovgaard; Kristiansen, Maiken Søndergaard

    2011-01-01

    from nucleoli, and consistently NEXT is specifically required for the exosomal degradation of promoter upstream transcripts (PROMPTs). We also detect putative homolog TRAMP subunits hTRF4-2 (Trf4p) and ZCCHC7 (Air2p) in hRRP6 and hMTR4 precipitates. However, at least ZCCHC7 function is restricted...... to nucleoli. Our results suggest that human nuclear exosome degradation pathways comprise modules of spatially organized cofactors that diverge from the yeast model....

  5. Mito-Nuclear Interactions Affecting Lifespan and Neurodegeneration in a Drosophila Model of Leigh Syndrome.

    Science.gov (United States)

    Loewen, Carin A; Ganetzky, Barry

    2018-04-01

    Proper mitochondrial activity depends upon proteins encoded by genes in the nuclear and mitochondrial genomes that must interact functionally and physically in a precisely coordinated manner. Consequently, mito-nuclear allelic interactions are thought to be of crucial importance on an evolutionary scale, as well as for manifestation of essential biological phenotypes, including those directly relevant to human disease. Nonetheless, detailed molecular understanding of mito-nuclear interactions is still lacking, and definitive examples of such interactions in vivo are sparse. Here we describe the characterization of a mutation in Drosophila ND23 , a nuclear gene encoding a highly conserved subunit of mitochondrial complex 1. This characterization led to the discovery of a mito-nuclear interaction that affects the ND23 mutant phenotype. ND23 mutants exhibit reduced lifespan, neurodegeneration, abnormal mitochondrial morphology, and decreased ATP levels. These phenotypes are similar to those observed in patients with Leigh syndrome, which is caused by mutations in a number of nuclear genes that encode mitochondrial proteins, including the human ortholog of ND23 A key feature of Leigh syndrome, and other mitochondrial disorders, is unexpected and unexplained phenotypic variability. We discovered that the phenotypic severity of ND23 mutations varies depending on the maternally inherited mitochondrial background. Sequence analysis of the relevant mitochondrial genomes identified several variants that are likely candidates for the phenotypic interaction with mutant ND23 , including a variant affecting a mitochondrially encoded component of complex I. Thus, our work provides an in vivo demonstration of the phenotypic importance of mito-nuclear interactions in the context of mitochondrial disease. Copyright © 2018 by the Genetics Society of America.

  6. Aerial Neutron Detection of Cosmic-Ray Interactions with the Earth's Surface

    International Nuclear Information System (INIS)

    Richard Maurer

    2008-01-01

    We have demonstrated the ability to measure the neutron flux produced by the cosmic-ray interaction with nuclei in the ground surface using aerial neutron detection. High energy cosmic-rays (primarily muons with GeV energies) interact with the nuclei in the ground surface and produce energetic neutrons via spallation. At the air-surface interface, the neutrons produced by spallation will either scatter within the surface material, become thermalized and reabsorbed, or be emitted into the air. The mean free path of energetic neutrons in air can be hundreds of feet as opposed to a few feet in dense materials. As such, the flux of neutrons escaping into the air provides a measure of the surface nuclei composition. It has been demonstrated that this effect can be measured at long range using neutron detectors on low flying helicopters. Radiological survey measurements conducted at Government Wash in Las Vegas, Nevada, have shown that the neutron background from the cosmic-soil interactions is repeatable and directly correlated to the geological data. Government Wash has a very unique geology, spanning a wide variety of nuclide mixtures and formations. The results of the preliminary measurements are presented

  7. FTZ-Factor1 and Fushi tarazu interact via conserved nuclear receptor and coactivator motifs

    Science.gov (United States)

    Schwartz, Carol J.E.; Sampson, Heidi M.; Hlousek, Daniela; Percival-Smith, Anthony; Copeland, John W.R.; Simmonds, Andrew J.; Krause, Henry M.

    2001-01-01

    To activate transcription, most nuclear receptor proteins require coactivators that bind to their ligand-binding domains (LBDs). The Drosophila FTZ-Factor1 (FTZ-F1) protein is a conserved member of the nuclear receptor superfamily, but was previously thought to lack an AF2 motif, a motif that is required for ligand and coactivator binding. Here we show that FTZ-F1 does have an AF2 motif and that it is required to bind a coactivator, the homeodomain-containing protein Fushi tarazu (FTZ). We also show that FTZ contains an AF2-interacting nuclear receptor box, the first to be found in a homeodomain protein. Both interaction motifs are shown to be necessary for physical interactions in vitro and for functional interactions in developing embryos. These unexpected findings have important implications for the conserved homologs of the two proteins. PMID:11157757

  8. X-ray diagnostics for laser matter interaction experiments; Diagnostics X pour les experiences d'interaction laser-matiere

    Energy Technology Data Exchange (ETDEWEB)

    Troussel, Ph

    2000-07-01

    Advances in the field of laser-driven inertially confined thermonuclear fusion research since the early 1990's are reviewed. It covers the experimental techniques used to study the interaction of laser radiation with matter and high density plasma. A high performance instrumentation (diagnostics) for observation of X radiation (from a few eV to a few keV) will be required to understand the physical processes involved in the interaction. This paper is a three-part: first part, describes diagnostics metrology realized around different X-ray sources (synchrotron, laser plasma...); a second part, synthesizes theoretical and experimental X-ray optics studies and show the interest for direct applications as X-ray spectroscopy and X-ray imaging around laser-produced plasma; a third part, is a review of high resolution X-ray imaging, performances of these optical system were summarized. (author)

  9. Study of fission products (Cs, Ba, Mo, Ru) behaviour in irradiated and simulated nuclear fuels during severe accidents using X-ray absorption Spectroscopy, SIMS and EPMA

    International Nuclear Information System (INIS)

    Geiger, Ernesto

    2016-01-01

    The identification of Fission Products (FP) release mechanism from irradiated nuclear fuels during a severe accident is of main importance for the development of codes for the estimation of the source-term (nature and quantity of radionuclides released into the environment). among the many FP Ba, Cs, Mo and Ru present a particular interest, since they may interact with each other or other elements and thus affect their release. In the framework of this thesis, two work axes have been set up in order to identify, firstly, the chemical phases initially present before the accident and, secondly, their evolution during the accident itself. The experimental approach consisted in reproducing nuclear severe accidents conditions at laboratory scale using both irradiated fuels and model materials (natural UO_2 doped with 12 FP). The advantage of these latter is the possibility of using characterization methods such as X-ray absorption Spectroscopy which are not available for irradiated fuels. Three irradiated fuel samples have been studied, representative to an initial state (before the accident), to an intermediate stage (1773 K) and to an advanced stage (2873 K) of a nuclear severe accident. Regarding to model materials, many accident sequences have been carried out, from 573 to 1973 K. Experimental results have allowed to establish a new release mechanism, considering both reducing and oxidizing conditions during an accident. These results have also demonstrated the importance of model materials as a complement to irradiated nuclear fuels in the study of nuclear severe accidents. (author) [fr

  10. Role of base damage in aberration formation: interaction of aphidicolin and x-rays

    International Nuclear Information System (INIS)

    Bender, M.A.; Preston, R.J.

    1981-01-01

    The base analog cytosine arabinoside (CA) is an inhibitor of DNA synthesis that is able to induce chromosomal aberrations not only in the DNA synthetic (S) phase of the cell cycle but in cells in the pre- (G 0 or G 1 ) and in the post-DNA-synthetic (G 2 ) phases of the cell cycle as well. Incubation of human peripheral lymphocytes in CA following either G 0 or G 2 x irradiation causes a synergistic increase in chromosomal aberration frequency. CA is believed to preferentially inhibit DNA polymerase α. It is suggested that it is inhibition of the repair of x-ray-induced base damage that is responsible for the synergistic effect on chromosomal aberration production observed with x-ray and CA treatment of human peripheral lymphocytes. It has also been observed that CA induces sister chromatid exchanges (SCE) in mammalian cells when present during normal DNA replication and that it also interacts synergistically with uv in the induction of SCE. A number of other inhibitors of DNA synthesis were also tested, one, aphidicolin (APC), did produce effects similar to CA at the same concentration. Aphidicolin is a tetracyclic diterpinoid that inhibits the growth of eukaryotic cells by inhibition of DNA synthesis. This action has been shown to result from specific inhibition of DNA polymerase α, but not of polymerases β or γ. Unlike CA, it seems likely that APC inhibits by binding to and inactivating the DNA-α polymerase complex. Because both CA and APC are α polymerase inhibitors and because both interact synergistically with uv in the production of SCE, studies were conducted to determine whether APC also shares other cytogenetic properties of CA. Results to date have shown that, like CA, APC is clastogenic in both G 0 and G 2 , and it also interacts synergistically with x rays to increase chromosomal aberration production in both G 0 and G 2

  11. Production of particle clustern in 50 GeV/cπ- -N and cosmic ray interactions

    International Nuclear Information System (INIS)

    Kaul, S.K.

    1977-01-01

    The role of particle clusters in multiple-pion production at accelerator and cosmic ray energies is studied employing the high multiplicity (nsub(c) > = 9) accelerator data at 50 GeV/c, and cosmic ray α-N and N-N data at 0.1-1.21 TeV and 0.25-42.3 TeV respectively. The clusters in individual interactions have been identified by employing three methods. In interactions where the measurement of the secondaries was possible, the parameters of the clusters were found from the kinematics of the cluster production process and in it rest of the cases the parameters were determined by the conventional method. A phenomeological investigation of the following aspects has been made: (i) mass and decay particles of the cluster, (ii) transverse momentum of the cluster, (iii) angular distribution of the secondary particles in the cluster system, and (iv) average momentum (Psub(0)) of the pions in the cluster-rest system. In majority of the events of each type of interactions, at least one cluster is emitted. The average characteristics of clusters produced in double and single cluster events have been found to be similar. The average mass of the cluster and the number of its charged decay particles have been found to be 1.79 +- 0.2 GeV and 5.78 +- 0.4 GeV respectively. Value of (Psub(0)) has been found to be (161.2 +- 12) MeV/c. It has been observed that the features of the clusters at accelerator and cosmic ray energies are almost similar. (author)

  12. Interaction effect of gamma rays and thermal neutrons on the inactivation of odontoglossum ringspot virus isolated from orchid

    International Nuclear Information System (INIS)

    Mori, Itsuhiko; Inouye, Narinobu.

    1977-01-01

    The effect of gamma rays or thermal neutrons and their interaction effects on the inactivation of the infectivity of Odontoglossum ringspot virus (ORSV) in buffered crude sap of the plant tissue were studied. The inactivation effect of gamma ray on ORSV varied in different ionic strength of the phosphate buffer solutions. Borax enhanced this effect. In interaction effect of gamma and neutron irradiation, irradiation orders, that is, n → γ and γ → n, gave different inactivation pattern. (author)

  13. Nuclear Material Accountability Applications of a Continuous Energy and Direction Gamma Ray Detector

    International Nuclear Information System (INIS)

    Gerts, David; Bean, Robert; Paff, Marc

    2010-01-01

    The Idaho National Laboratory has recently developed a detector system based on the principle of a Wilson cloud chamber that gives the original energy and direction to a gamma ray source. This detector has the properties that the energy resolution is continuous and the direction to the source can be resolved to desired fidelity. Furthermore, the detector has low power requirements, is durable, operates in widely varying environments, and is relatively cheap to produce. This detector is expected, however, to require significant time to perform measurements. To mitigate the significant time for measurements, the detector is expected to scale to very large sizes with a linear increase in cost. For example, the proof of principle detector is approximately 30,000 cm3. This work describes the technical results that lead to these assertions. Finally, the applications of this detector are described in the context of nuclear material accountability.

  14. Determination of trace metals in nuclear-grade uranium dioxide by X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Salvador, V.L.R.; Imakuma, K.

    1988-04-01

    A method is described for the simultaneous determination of low concentrations of Ca, Cr, Cu, Fe, Mn and Ni in nuclear-grade uranium dioxide by X-ray fluorescence spectrometry, without the use of chemical treatment. The lower limits of detection range from 2 μg g -1 for nickel and manganese to 5 μg g -1 for copper. Samples are prepared in the form of double-layer pellets with boric acid as a binding agent. Standards are prepared in a U 3 O 8 matrix, which is more chemically stable than UO 2 and has similar matrix behaviour. The correlation coefficients for calibration curves are better than 0.999. Erros range from 2.4 % for chromium to 6.8 % for nickel. (author) [pt

  15. Some notes on data analysis for nuclear resonant inelastic x-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Michael Y., E-mail: myhu@aps.anl.gov [Argonne National Laboratory (United States)

    2016-12-15

    Nuclear Resonant Inelastic X-ray Scattering (NRIXS) is a spectroscopy method to study atomic vibrations and dynamics, currently done with synchrotron radiation at a few high energy third generation facilities. It finds a wide range of applications in condensed matter physics, materials science, chemistry, biophysics, geosciences, and high-pressure researches. Many atomic dynamics and lattice thermodynamics information can be derived from NRIXS measurements. Phonon Density of States (DOS) characterizes lattice dynamics of a material and can be derived under the quasi-harmonic approximation. Combined with modeling and simulations, results from NRIXS can provide unique and clarifying insights into many fields of research. As for a spectroscopic technique, in order to be able to provide reliable information, close attention should be paid to many issues during experiments and data analysis afterwards. Here we discuss several issues relevant to its data analysis, namely, those of multiple sites, background treatments, and error estimates for some derived quantities.

  16. Analyses of Interaction Phases of U Mo Dispersion Fuel by Synchrotron X ray Diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Woo Jeong; Nam, Ji Min; Ryu, Ho Jin; Park, Jong Man [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Herve, Palancher; Charollais, Francois [Saint Paul Lez Durance Cedex, Rhone (France); Bonnin, Anne; Honkimaeki, Veijo [Grenoble Cedex, Grenoble (France); Patrick Lemoined [Gif sur Yvette, Paris (France)

    2012-10-15

    Gamma phase U Mo alloys are one of the promising candidates to be used as advanced high uranium density fuel for high power research reactors due to their excellent irradiation performance. However, formation of interaction layers between the U Mo particles and Al matrix degrades the irradiation performance of U Mo dispersion fuel. One of the remedies to the interaction problem is a Si addition to the Al matrix. Recent irradiation tests have shown that the use of Al (2{approx}5wt%)Si matrices retarded the growth of interaction layers effectively during irradiation. Recently, KAERI has proposed silicide or nitride coated U Mo fuel for the minimization of the interaction layer growth. The silicide or nitride coatings are expected to act as interdiffusion barriers and their out of pile tests showed the improved diffusion barrier performances of the silicide and nitride layers. In order to characterize constituent phases in the coated layers on U Mo particles and the interaction layers of coated U Mo particle dispersed fuel, synchrotron X ray diffraction experiments have been performed at the ESRF (European Synchrotron Radiation Facility), France as a KAERI CEA cooperation program.

  17. Lunar and Martian environmental interactions with nuclear power system radiators

    International Nuclear Information System (INIS)

    Perez-Davis, M.E.; Gaier, J.R.; Katzan, C.M.

    1994-01-01

    In the foreseeable future, NASA space milestones include a permanent manned presence on the Moon and an expedition to the planet Mars. Such steps will require careful consideration of environmental interactions in the selection and design of required power systems. Several environmental constituents may be hazardous to performance integrity. Potential threats common to both the Moon and Mars are low ambient temperatures, wide daily temperature swings, solar flux, and large quantities of dust. The surface of Mars provides the additional challenges of dust storms, winds, and a carbon dioxide atmosphere. In this review, the anticipated environmental interactions with surface power system radiators are described, as well as the impacts of these interactions on radiator durability, which have been identified at NASA Lewis Research Center

  18. The proton-neutron interaction and nuclear collectivity

    International Nuclear Information System (INIS)

    Casten, R.F.

    1987-01-01

    A review is given of several aspects, and empirical consequences, of the p-n interaction as it relates to the structure, phase transitions and collectivity of medium and heavy nuclei. The N/sub p/N/sub n/ scheme is reviewed as background material while the emphasis centers on a discussion of a related quantity, the P factor, and on the relationship of the integrated strength of the p-n interaction to the empirically observed ''saturation'' of B(E2) values in the mid-shell regions of deformed nuclei. 19 refs., 13 figs

  19. Azimuthal asymmetry of slow particles in high energy nuclear interaction

    International Nuclear Information System (INIS)

    Sarkar, Subir; Goswami, T.D.

    2002-01-01

    An asymmetry in the angular distribution of slow particles in the azimuthal plane has been observed during high energy nuclear disintegration of photo emulsion nuclei exposed to 1.8 GeV/c k - and 20 GeV/c protons. The mechanism of disintegration is not in accordance with the cascade-evaporation model, which is based on isotropic emission of slow particles. Deviation from isotropy indicates that some of the slow particles might be emitted well before the thermal equilibrium is reached in the disintegrating system. (author)

  20. DNA-nuclear matrix interactions and ionizing radiation sensitivity

    International Nuclear Information System (INIS)

    Schwartz, J.L.; Vaughan, A.T.M.

    1993-01-01

    The association between inherent ionizing radiation sensitivity and DNA supercoil unwinding in mammalian cells suggests that the organization of the DNA in chromosomes plays an important role in radiation responses. In this paper, a model is proposed which suggests that these DNA unwinding alterations reflect differences in the attachment of DNA to the nuclear matrix. In radioresistant cells, the MAR structure might exist in a more stable, open configuration, limiting DNA unwinding following strand break induction and influencing the rate and nature of DNA double-strand break rejoining

  1. DNA-nuclear matrix interactions and ionizing radiation sensitivity

    International Nuclear Information System (INIS)

    Schwartz, J.L.; Chicago Univ., IL; Vaughan, A.T.M.

    1993-01-01

    The association between inherent ionizing radiation sensitivity and DNA supercoil unwinding in mammalian cells suggests that the DNA-nuclear matrix attachment region (MAR) plays an important role in radiation response. In radioresistant cells, the MAR structure may exist in a more stable, open configuration, limiting DNA unwinding following strand break induction and maintaining DNA ends in close proximity for more rapid and accurate rejoining. In addition, the open configuration at these matrix attachment sites may serve to facilitate rapid DNA processing of breaks by providing (1) sites for repair proteins to collect and (2) energy to drive enzymatic reactions

  2. Water penetration mechanisms in nuclear glasses by X-ray and neutron reflectometry

    International Nuclear Information System (INIS)

    Rebiscoul, D.; Rieutord, F.; Ne, F.; Frugier, P.; Gin, S.; Cubitt, R.

    2007-01-01

    To determine the water diffusion at the early stage of the alteration, X-ray and neutron reflectometry have been performed on altered simplified glasses and the SON68 glass (an inactive R7T7-type French nuclear glass). For the first experiment, the simplified and SON68 glasses were altered at pH 3 and pH 6 and characterized by X-ray reflectometry as a function of the alteration duration. The evolutions of the electron density profile obtained from the reflectivity curves simulations have allowed the determination of the layers compositions. At the beginning of the alteration and for pH 3, the altered surface layer is constituted of a dealkalized zone. Upon alteration progress, the water diffuses inside the layer and hydrolyzes the Si-O-B bonds. For the second experiment, glasses were altered in D 2 O (pD 3) and analyzed in D 2 O saturated cell. After a D 2 O/H 2 O substitution, the samples were characterized one more time in H 2 O saturated cell. The evolution of the scattering length density shows that in the first stage of the alteration, the layer is constituted of two parts: a dealkalized glass and a dealkalized and boron depleted glass where water has diffused. According to the glass composition and after few hours of alteration, this dealkalized glass part can disappear. (authors)

  3. Nuclear and atomic physics governing changes in the composition of relativistic cosmic rays

    International Nuclear Information System (INIS)

    Wilson, L.W.

    1978-05-01

    Many quantitative studies of relativistic cosmic ray propagation exist in which ''standard'' values for the input quantities are adopted in an uncritical manner. In contrast, the major emphasis of this study is on developing the proper set of formulae and error estimates for each of the atomic and nuclear processes that govern the composition of the cosmic rays between lithium and nickel. In particular, it is shown that errors of approximately a factor of two exist in the standard (Bohr) cross sections for stripping, that the correction function from high energy photoionization needs to be introduced into the standard cross section for radiative attachment, and that because the half-life of a fast nucleus with at most one K-shell electron can differ from the half-life of a neutral atom, several laboratory-based values need correction. The framework used to assemble and correct these quantities is a matrix formalism for the leaky box model similar to that used by Cowsik and Wilson in their ''nested leaky box'' model. It is shown that once the assumption of species-independent leakage is introduced, the matrix formalism becomes virtually identical with the standard exponential path length formalism. 87 references

  4. Laue optics for nuclear astrophysics: New detector requirements for focused gamma-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Barriere, N. [INAF - IASF Roma, via Fosso del Cavaliere 100, 00133 Roma (Italy)], E-mail: nicolas.barriere@iasf-roma.inaf.it; Ballmoos, P. von [CESR - UMR 5187, 9 Av. du Colonel Roche, 31028 Toulouse (France); Abrosimov, N.V. [IKZ, Max Born-Str. 2, D-12489 Berlin (Germany); Bastie, P. [LSP UMR 5588, 140 Av. de la physique, 38402 Saint Martin d' Heres (France); Camus, T. [CESR - UMR 5187, 9 Av. du Colonel Roche, 31028 Toulouse (France); Courtois, P.; Jentschel, M. [ILL, 6 rue Jules Horowitz, 38042 Grenoble (France); Knoedlseder, J. [CESR - UMR 5187, 9 Av. du Colonel Roche, 31028 Toulouse (France); Natalucci, L. [INAF - IASF Roma, via Fosso del Cavaliere 100, 00133 Roma (Italy); Roudil, G.; Rousselle, J. [CESR - UMR 5187, 9 Av. du Colonel Roche, 31028 Toulouse (France); Wunderer, C.B. [SSL, University of California at Berkeley, CA 94708 (United States); Kurlov, V.N. [Institute of Solid State Physics of Russian Academy of Sciences, 142432 Chernogolovka (Russian Federation)

    2009-10-21

    Nuclear astrophysics presents an extraordinary scientific potential for the study of the most powerful sources and the most violent events in the Universe. But in order to take full advantage of this potential, telescopes should be at least an order of magnitude more sensitive than present technologies. Today, Laue lenses have demonstrated their capability of focusing gamma-rays in the 100 keV-1 MeV domain, enabling the possibility of building a new generation of instruments for which sensitive area is decoupled from collecting area. Thus we have now the opportunity of dramatically increase the signal/background ratio and hence improve significantly the sensitivity. With a lens, the best detector is no longer the largest possible within a mission envelope. The point spread function of a Laue lens measures a few centimeters in diameter, but the field of view is limited by the detector size. Requirements for a focal plane instrument are presented in the context of the Gamma-Ray Imager mission (proposed to European Space Agency, ESA in the framework of the first Cosmic Vision AO): a 15-20 cm a side finely pixellated detector capable of Compton events reconstruction seems to be optimal, giving polarization and background rejection capabilities and 30 arcsec of angular resolution within a field of view of 5 arc min.

  5. Mean multiplicity of secondary particles in hadron-nuclear interactions

    International Nuclear Information System (INIS)

    Alaverdyan, G.B.; Pak, A.S.

    1980-01-01

    The mean multiplicity of secondary particles in hA interactions is examined in the framework of the multiplex scattering theory. The dependence of the secondary particle multiplicity coefficient Rsub(6)=anti nsub(hA)/anti nsub(hN) (where anti nsub(hA) and anti nsub(hN) are mean multiplicities of secondary relativistic particles in hA and hN interactions, respectively) on the energy and type of incident particles and atomic number of a target nucleus is analysed. It is shown that predictions of the leading particle cascade model are in satisfactory agreement with the experimental data if the uncertainties of the inelasticity in hN interactions are taken into account. The value Rsub(A) weakly depends both on the incident particle energy and the form of parametrization anti nsub(hN)(E). Allowance of energy losses fluctuation of leading particle results in the Rsub(A) value decrease. From the model of leading particles it does not follow that Rsub(a) strictly depends on the type of incident particles at the fixed value of mean number of collisions. But quantitative values of Rsub(A) for different types of particles and at one value of anti ν, (i.e. at properly chosen value) coincide. The value of Rsub(A) is profoundly dependent on the values of inelasticity factor in hN interactions

  6. Detecting special nuclear materials in suspect containers using high-energy gamma rays emitted by fission products

    Science.gov (United States)

    Norman, Eric B [Oakland, CA; Prussin, Stanley G [Kensington, CA

    2009-01-27

    A method and a system for detecting the presence of special nuclear materials in a suspect container. The system and its method include irradiating the suspect container with a beam of neutrons, so as to induce a thermal fission in a portion of the special nuclear materials, detecting the gamma rays that are emitted from the fission products formed by the thermal fission, to produce a detector signal, comparing the detector signal with a threshold value to form a comparison, and detecting the presence of the special nuclear materials using the comparison.

  7. X-Ray Emission from the Nuclear Region of Arp 220

    Science.gov (United States)

    Paggi, Alessandro; Fabbiano, Giuseppina; Risaliti, Guido; Wang, Junfeng; Karovska, Margarita; Elvis, Martin; Maksym, W. Peter; McDowell, Jonathan; Gallagher, Jay

    2017-05-01

    We present an imaging and spectral analysis of the nuclear region of the ultraluminous infrared galaxy merger of Arp 220, using deep Chandra-ACIS observations summing up to ˜ 300 {{ks}}. Narrowband imaging with subpixel resolution of the innermost nuclear region reveals two distinct Fe-K emitting sources, coincident with the infrared and radio nuclear clusters. These sources are separated by 1‧ (˜380 pc). The X-ray emission is extended and elongated in the eastern (E) nucleus, like the disk emission observed in millimeter radio images, suggesting a starburst dominance in this region. We estimate an Fe-K equivalent width of ≳ 1 {keV} for both sources and observe 2-10 keV luminosities of ˜ 2× {10}40 {{erg}} {{{s}}}-1 (western, W) and ˜ 3× {10}40 {{erg}} {{{s}}}-1 (E). In the 6-7 keV band the emission from these regions is dominated by the 6.7 keV Fe xxv line, suggesting a contribution from collisionally ionized gas. The thermal energy content of this gas is consistent with the kinetic energy injection in the interstellar medium by SNe II. However, nuclear winds from a hidden active galactic nucleus (AGN) (\\upsilon ˜ 2000 {{km}} {{{s}}}-1) cannot be excluded. The 3σ upper limits on the neutral Fe-Kα flux of the nuclear regions correspond to the intrinsic AGN 2-10 keV luminosities of < 1× {10}42 {{erg}} {{{s}}}-1 (W) and < 0.4× {10}42 {{erg}} {{{s}}}-1 (E). For typical AGN spectral energy distributions the bolometric luminosities are < 3× {10}43 {{erg}} {{{s}}}-1 (W) and < 8× {10}43 {{erg}} {{{s}}}-1 (E), and black hole masses of < 1× {10}5 {M}⊙ (W) and < 5× {10}5 {M}⊙ (E) are evaluated for Eddington limited AGNs with a standard 10% efficiency.

  8. Evaluation of the total gamma-ray production cross-sections for nonelastic interaction of fast neutrons with iron nuclei

    International Nuclear Information System (INIS)

    Savin, M.V.; Nefedov, Yu.Ya; Livke, A.V.; Zvenigorodskij, A.G.

    2001-01-01

    Experimental data on the total gamma-ray production cross-sections for inelastic interaction of fast neutrons with iron nuclei were analysed. The total gamma-ray production cross-sections, grouped according to E γ , were evaluated in the neutron energy range 0.5-19 MeV. The statistical spline approximation method was used to evaluate the experimental data. Evaluated data stored in the ENDF, JENDL, BROND, and other libraries on gamma-ray production spectra and cross-sections for inelastic interaction of fast neutrons with iron nuclei, were analysed. (author)

  9. Towards modeling of nonlinear laser-plasma interactions with hydrocodes: The thick-ray approach

    Science.gov (United States)

    Colaïtis, A.; Duchateau, G.; Nicolaï, P.; Tikhonchuk, V.

    2014-03-01

    This paper deals with the computation of laser beam intensity in large-scale radiative hydrocodes applied to the modeling of nonlinear laser-plasma interactions (LPIs) in inertial confinement fusion (ICF). The paraxial complex geometrical optics (PCGO) is adapted for light waves in an inhomogeneous medium and modified to include the inverse bremsstrahlung absorption and the ponderomotive force. This thick-ray model is compared to the standard ray-tracing (RT) approach, both in the chic code. The PCGO model leads to different power deposition patterns and better diffraction modeling compared to standard RT codes. The intensity-reconstruction technique used in RT codes to model nonlinear LPI leads to artificial filamentation and fails to reproduce realistic ponderomotive self-focusing distances, intensity amplifications, and density channel depletions, whereas PCGO succeeds. Bundles of Gaussian thick rays can be used to model realistic non-Gaussian ICF beams. The PCGO approach is expected to improve the accuracy of ICF simulations and serve as a basis to implement diverse LPI effects in large-scale hydrocodes.

  10. A prototype scintillating-fibre tracker for the cosmic-ray muon tomography of legacy nuclear waste containers

    Energy Technology Data Exchange (ETDEWEB)

    Mahon, D.F., E-mail: David.Mahon@Glasgow.ac.uk [Nuclear Physics Group, University of Glasgow, Kelvin Building, University Avenue, Glasgow, G12 8QQ Scotland (United Kingdom); Clarkson, A.; Hamilton, D.J.; Hoek, M.; Ireland, D.G. [Nuclear Physics Group, University of Glasgow, Kelvin Building, University Avenue, Glasgow, G12 8QQ Scotland (United Kingdom); Johnstone, J.R. [National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, Cumbria, CA20 1PG England (United Kingdom); Kaiser, R.; Keri, T.; Lumsden, S.; McKinnon, B.; Murray, M.; Nutbeam-Tuffs, S. [Nuclear Physics Group, University of Glasgow, Kelvin Building, University Avenue, Glasgow, G12 8QQ Scotland (United Kingdom); Shearer, C.; Staines, C. [National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, Cumbria, CA20 1PG England (United Kingdom); Yang, G. [Nuclear Physics Group, University of Glasgow, Kelvin Building, University Avenue, Glasgow, G12 8QQ Scotland (United Kingdom); Zimmerman, C. [National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, Cumbria, CA20 1PG England (United Kingdom)

    2013-12-21

    Cosmic-ray muons are highly penetrative charged particles observed at sea level with a flux of approximately 1 cm{sup −2} min{sup −1}. They interact with matter primarily through Coulomb scattering which can be exploited in muon tomography to image objects within industrial nuclear waste containers. A prototype scintillating-fibre detector has been developed for this application, consisting of two tracking modules above and below the volume to be assayed. Each module comprises two orthogonal planes of 2 mm fibres. The modular configuration allows the reconstruction of the initial and scattered muon trajectories which enable the container content, with respect to atomic number Z, to be determined. Fibre signals are read out by Hamamatsu H8500 MAPMTs with two fibres coupled to each pixel via dedicated pairing schemes developed to avoid space point ambiguities and retain the high spatial resolution of the fibres. A likelihood-based image reconstruction algorithm was developed and tested using a GEANT4 simulation of the prototype system. Images reconstructed from this simulation are presented in comparison with experimental results taken with test objects. These results verify the simulation and show discrimination between the low, medium and high-Z materials imaged.

  11. Heat shock-induced interactions among nuclear HSFs detected by fluorescence cross-correlation spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Pack, Chan-Gi, E-mail: changipack@amc.seoul.kr [Asan Institute for Life Sciences, University of Ulsan, College of Medicine, Asan Medical Center, Seoul 138-736 (Korea, Republic of); Ahn, Sang-Gun [Dept. of Pathology, College of Dentistry, Chosun University, Seosuk-dong, Dong-gu, Gwangju 501-759 (Korea, Republic of)

    2015-07-31

    The cellular response to stress is primarily controlled in cells via transcriptional activation by heat shock factor 1 (HSF1). HSF1 is well-known to form homotrimers for activation upon heat shock and subsequently bind to target DNAs, such as heat-shock elements, by forming stress granules. A previous study demonstrated that nuclear HSF1 and HSF2 molecules in live cells interacted with target DNAs on the stress granules. However, the process underlying the binding interactions of HSF family in cells upon heat shock remains unclear. This study demonstrate for the first time that the interaction kinetics among nuclear HSF1, HSF2, and HSF4 upon heat shock can be detected directly in live cells using dual color fluorescence cross-correlation spectroscopy (FCCS). FCCS analyses indicated that the binding between HSFs was dramatically changed by heat shock. Interestingly, the recovery kinetics of interaction between HSF1 molecules after heat shock could be represented by changes in the relative interaction amplitude and mobility. - Highlights: • The binding interactions among nuclear HSFs were successfully detected. • The binding kinetics between HSF1s during recovery was quantified. • HSF2 and HSF4 strongly formed hetero-complex, even before heat shock. • Nuclear HSF2 and HSF4 bound to HSF1 only after heat shock.

  12. Fanconi Anemia Proteins FANCA, FANCC, and FANCG/XRCC9 Interact in a Functional Nuclear Complex

    OpenAIRE

    Garcia-Higuera, Irene; Kuang, Yanan; Näf, Dieter; Wasik, Jennifer; D’Andrea, Alan D.

    1999-01-01

    Fanconi anemia (FA) is an autosomal recessive cancer susceptibility syndrome with at least eight complementation groups (A to H). Three FA genes, corresponding to complementation groups A, C, and G, have been cloned, but their cellular function remains unknown. We have previously demonstrated that the FANCA and FANCC proteins interact and form a nuclear complex in normal cells, suggesting that the proteins cooperate in a nuclear function. In this report, we demonstrate that the recently clone...

  13. Shocks from high-energy nuclear-interacting particles in the mountain Chakaltajya

    Energy Technology Data Exchange (ETDEWEB)

    Kamata, K [Tokyo Univ. (Japan)

    1975-06-01

    Experimental investigations of extensive air showers at the height of 5200 m above the sea level have been performed. The behaviour of high energy nuclear active particles in the cores of the showers has been studied using the nuclear knock-on method. The cross section of the proton inelastic interaction with the air is shown to increase with energy in the energy range of 3-9 TeV.

  14. Modeling nuclear weak-interaction processes with relativistic energy density functionals

    International Nuclear Information System (INIS)

    Paar, N.; Marketin, T.; Vale, D.; Vretenar, D.

    2015-01-01

    Relativistic energy density functionals have become a standard framework for nuclear structure studies of ground state properties and collective excitations over the entire nuclide chart. In this paper, we review recent developments in modeling nuclear weak-interaction processes: Charge-exchange excitations and the role of isoscalar proton–neutron pairing, charged-current neutrino–nucleus reactions relevant for supernova evolution and neutrino detectors and calculation of β-decay rates for r-process nucleosynthesis. (author)

  15. Man-machine interaction in Canadian nuclear power plants

    International Nuclear Information System (INIS)

    Olmstead, R.A.

    1994-01-01

    The design of man-machine interaction in the CANDU plants has evolved considerably over several generations of plants, from the first Douglas Point plant through to the next generation of plants represented by new designs like CANDU 3. In the early plants, the control room configuration was based on designers' projections of control interface requirements. With succeeding generations of designs, there has been an evolution towards a more systematic consideration of human strengths and weaknesses, increasing attention to formal requirements definition, and incorporation of a larger base of operational experience. This paper describes the design of the man-machine interaction for third generation CANDU-3 control rooms for improved operator reliability and reduced costs. (author). 13 refs., 3 figs

  16. Reduction of nuclear moment of inertia due to pairing interaction

    International Nuclear Information System (INIS)

    Zeng, J.Y.; Jin, T.H.; Zhao, Z.J.

    1994-01-01

    The BCS theoretical values of the moments of inertia of even-even nuclei are systematically smaller than the experimental ones by a factor of 10--40%. This long-standing discrepancy disappears in the particle-number-conserving treatment for the cranked shell model, in which the blocking effects are taken into account exactly. The calculated moments of inertia satisfactorily reproduce the experimental data covering a large number of rare-earth even-even nuclei, whose deformations and single-particle states are well characterized (Lund systematics). The pairing interaction strength G is unambiguously determined by the even-odd mass difference. The reduction of the moment of inertia due to the antialignment effect of pairing interaction is discussed and no systematic excessive reduction is found

  17. Concealed nuclear material identification via combined fast-neutron/γ-ray computed tomography (FNGCT): a Monte Carlo study

    Science.gov (United States)

    Licata, M.; Joyce, M. J.

    2018-02-01

    The potential of a combined and simultaneous fast-neutron/γ-ray computed tomography technique using Monte Carlo simulations is described. This technique is applied on the basis of a hypothetical tomography system comprising an isotopic radiation source (americium-beryllium) and a number (13) of organic scintillation detectors for the production and detection of both fast neutrons and γ rays, respectively. Via a combination of γ-ray and fast neutron tomography the potential is demonstrated to discern nuclear materials, such as compounds comprising plutonium and uranium, from substances that are used widely for neutron moderation and shielding. This discrimination is achieved on the basis of the difference in the attenuation characteristics of these substances. Discrimination of a variety of nuclear material compounds from shielding/moderating substances (the latter comprising lead or polyethylene for example) is shown to be challenging when using either γ-ray or neutron tomography in isolation of one another. Much-improved contrast is obtained for a combination of these tomographic modalities. This method has potential applications for in-situ, non-destructive assessments in nuclear security, safeguards, waste management and related requirements in the nuclear industry.

  18. Binding energies of hypernuclei and Λ-nuclear interactions

    International Nuclear Information System (INIS)

    Bodmer, A.R.; Usmani, Q.N.

    1984-01-01

    Variational calculations indicate that a reasonable description of Λp scattering and of Λ separation energies can be obtained in terms of ΛN plus dispersive and TPE ΛNN forces. Results for the ΛΛ interaction and for 6 /sub Λ/He obtained from an analysis of 10 /sub ΛΛ/Be are discussed. Coulomb and ΛN charge symmetry breaking effects in the A = 4 hypernuclei are discussed

  19. Development of EPSILON. A gamma ray imaging system for the nuclear industry

    International Nuclear Information System (INIS)

    Durrant, P.T.

    1999-06-01

    In recent years, much effort has been focused on the need to characterise, stabilise, decontaminate and eventually decommission radioactively contaminated nuclear facilities. These tasks can be complex and hazardous and are often hampered by a lack of knowledge of the nature and distribution of the contamination. A gamma-ray imaging system, capable of remotely mapping a contaminated scene, could be a useful tool in many tasks related to the decommissioning of nuclear facilities. This thesis describes and discusses the design, development, commissioning and characterisation of EPSILON, a multipurpose gamma-ray imaging system designed to meet the needs of a range of applications in the nuclear industry. Following a review of the range of potential applications and a critical assessment of the imaging systems available at the time, a set of design criteria for a multi-purpose gamma-ray imaging system are identified. The design and development of an imaging system to meet these criteria is described in detail. Suitable image-formation techniques are discussed and a pinhole collimator selected as the most appropriate. Consideration is given to the use of a scintillator-photodiode array as the imager detection plane but this option is rejected in favour of a position-sensitive photomultiplier tube (PSPMT). The development of two data-acquisition systems is described and comparisons made between the performance of these two techniques. The factors affecting the performance and image quality of this pinhole imaging system are discussed and a prototype design presented for a well-shielded, high-sensitivity imager. Experimental results obtained with this prototype are presented. These results demonstrate a good angular resolution of 1.6 deg across a 12.8 deg FOV and a factor of 7 improvement in sensitivity over a comparable resolution, single-pixel scanning-system. The spectral resolution of this prototype imager did not meet the design criteria. A modified design is

  20. Nuclear structure calculations in the dynamic-interaction propagator approach

    International Nuclear Information System (INIS)

    Engelbrecht, C.A.; Hahne, F.J.W.; Heiss, W.D.

    1978-01-01

    The dynamic-interaction propagator approach provides a natural method for the handling of energy-dependent effective two-body interactions induced by collective excitations of a many-body system. In this work this technique is applied to the calculation of energy spectra and two-particle strengths in mass-18 nuclei. The energy dependence is induced by the dynamic exchange of the lowest 3 - octupole phonon in O 16 , which is described within a normal static particle-hole RPA. This leads to poles in the two-body self-energy, which can be calculated if other fermion lines are restricted to particle states. The two-body interaction parameters are chosen to provide the correct phonon energy and reasonable negative-parity mass-17 and positive-parity mass-18 spectra. The fermion lines must be dressed consistently with the same exchange phonon to avoid redundant solutions or ghosts. The negative-parity states are then calculated in a parameter-free way which gives good agreement with the observed spectra [af

  1. The Origin of the Extra-nuclear X-ray Emission in the Seyfert Galaxy NGC 2992

    Science.gov (United States)

    Colbert, E. J. M.; Strickland, D. K.; Veilleux, S.; Weaver, K. A.

    2004-12-01

    We present an analysis of a Chandra ACIS observation of the edge-on Seyfert galaxy NGC 2992. We find extended X-ray emission with Lx(total) in excess of 10**40 erg/s. The brightest nebula is positioned a few 100 pc from the X-ray core, and is spatially coincident with optical line and radio emission. This emission nebula may be energized by the AGN, as opposed to a nuclear starburst. The expected kpc-scale X-ray emission due to a starburst-driven wind is larger than a few 10**39 erg/s, and we present large-scale X-ray emission that may be associated with such an outflow. The extra-nuclear emission has a very soft spectrum. Chandra and XMM spectra of the total nuclear region show a very prominent ``soft excess'' below 2-3 keV. We shall discuss the spectral properties of this soft excess, and will compare with the results from the spatial analysis, and with AGN and starburst models for extranuclear X-ray nebulae.

  2. Interactions of rat repetitive sequence MspI8 with nuclear matrix proteins during spermatogenesis

    International Nuclear Information System (INIS)

    Rogolinski, J.; Widlak, P.; Rzeszowska-Wolny, J.

    1996-01-01

    Using the Southwestern blot analysis we have studied the interactions between rat repetitive sequence MspI8 and the nuclear matrix proteins of rats testis cells. Starting from 2 weeks the young to adult animal showed differences in type of testis nuclear matrix proteins recognizing the MspI8 sequence. The same sets of nuclear matrix proteins were detected in some enriched in spermatocytes and spermatids and obtained after fractionation of cells of adult animal by the velocity sedimentation technique. (author). 21 refs, 5 figs

  3. The electron-spin--nuclear-spin interaction studied by polarized neutron scattering.

    Science.gov (United States)

    Stuhrmann, Heinrich B

    2007-11-01

    Dynamic nuclear spin polarization (DNP) is mediated by the dipolar interaction of paramagnetic centres with nuclear spins. This process is most likely to occur near paramagnetic centres at an angle close to 45 degrees with respect to the direction of the external magnetic field. The resulting distribution of polarized nuclear spins leads to an anisotropy of the polarized neutron scattering pattern, even with randomly oriented radical molecules. The corresponding cross section of polarized coherent neutron scattering in terms of a multipole expansion is derived for radical molecules in solution. An application using data of time-resolved polarized neutron scattering from an organic chromium(V) molecule is tested.

  4. Mutations induced by X-rays and UV radiation during the nuclear cycle in the yeast Schizosarccharomyces pombe

    International Nuclear Information System (INIS)

    Barale, R.; Rusciano, D.; Loprieno, N.

    1982-01-01

    The availability of a cell-division-cycle (cdc) mutant in the fission yeast S. pombe, wee 1-50, has made possible the production of a large population of G 1 nuclear-stage synchronized cells. During their development, yeast cells from the G 1 into the G 2 nuclear stages were treated with X-rays and UV radiation at various doses. The DNA pre-replicative and replicative phases were the most sensitive to both cell lethality and mutant induction with either X-rays or UV radiation. The trends of induced biological effects that were observed suggest that the induction of mutations is dependent on the number of unrepaired DNA lesions that reach the replicating fork or of those that occur at that time. The X-ray-induced mutations were earlier saturated, possibly because of the higher number of lethal lesions so induced. (orig.)

  5. Nuclear effect study on nucleon structure functions, in comparison with antineutrino interactions on neon and deuterium

    International Nuclear Information System (INIS)

    Vallee, C.

    1984-03-01

    We have studied the nuclear effects on high energy antineutrino charged current interactions by comparing the data which were taken in the Bubble Chamber BEBC filled with Neon and Deuterium. On the one hand, the study of nuclear reinteractions gave us the possibility to estimate the formation time of hadrons. On the other hand, the comparison of structure functions does not show any significant difference between Neon and Deuterium. Though this result does not contradict the effects observed with charged leptons by the EMC and SLAC experiments, it is strongly incompatible with certain theoretical interpretations which implied a stronger effect in antineutrino interactions [fr

  6. Rapid, portable detection of endocrine disrupting chemicals through ligand-nuclear hormone receptor interactions.

    Science.gov (United States)

    Hunt, J Porter; Schinn, Song-Min; Jones, Matthew D; Bundy, Bradley C

    2017-12-04

    Endocrine disrupting chemicals (EDC) are structurally diverse compounds that can interact with nuclear hormone receptors, posing significant risk to human and ecological health. Unfortunately, many conventional biosensors have been too structure-specific, labor-intensive or laboratory-oriented to detect broad ranges of EDC effectively. Recently, several technological advances are providing more rapid, portable, and affordable detection of endocrine-disrupting activity through ligand-nuclear hormone receptor interactions. Here, we overview these recent advances applied to EDC biosensors - including cell lyophilization, cell immobilization, cell-free systems, smartphone-based signal detection, and improved competitive binding assays.

  7. RanBP3 influences interactions between CRM1 and its nuclear protein export substrates

    OpenAIRE

    Englmeier, Ludwig; Fornerod, Maarten; Bischoff, F. Ralf; Petosa, Carlo; Mattaj, Iain W.; Kutay, Ulrike

    2001-01-01

    We investigated the role of RanBP3, a nuclear member of the Ran-binding protein 1 family, in CRM1-mediated protein export in higher eukaryotes. RanBP3 interacts directly with CRM1 and also forms a trimeric complex with CRM1 and RanGTP. However, RanBP3 does not bind to CRM1 like an export substrate. Instead, it can stabilize CRM1–export substrate interaction. Nuclear RanBP3 stimulates CRM1-dependent protein export in permeabilized cells. These data indicate that RanBP3 functions by a novel mec...

  8. Two pion mediated scalar isoscalar NN interaction in the nuclear medium

    International Nuclear Information System (INIS)

    Kaskulov, Murat M.; Oset, E.; Vacas, M.J. Vicente

    2006-01-01

    We study the modification of the nucleon-nucleon interaction in a nuclear medium in the scalar isoscalar channel, mediated by the exchange of two correlated (σ channel) or uncorrelated pions. For this purpose we use a standard approach for the renormalization of pions in nuclei. The corrections obtained for the NN interaction in the medium in this channel are of the order of 20% of the free one in average, and the consideration of short-range correlations plays an important role in providing these moderate changes. Yet, the corrections are sizable enough to suggest further studies of the stability and properties of nuclear matter

  9. X ray emission: a tool and a probe for laser - clusters interaction; L'emission X: un outil et une sonde pour l'interaction laser - agregats

    Energy Technology Data Exchange (ETDEWEB)

    Prigent, Ch

    2004-12-01

    In intense laser-cluster interaction, the experimental results show a strong energetic coupling between radiation and matter. We have measured absolute X-ray yields and charge state distributions under well control conditions as a function of physical parameters governing the interaction; namely laser intensity, pulse duration, wavelength or polarization state of the laser light, the size and the species of the clusters (Ar, Kr, Xe). We have highlighted, for the first time, an intensity threshold in the X-ray production very low ({approx} 2.10{sup 14} W/cm{sup 2} for a pulse duration of 300 fs) which can results from an effect of the dynamical polarisation of clusters in an intense electric field. A weak dependence with the wavelength (400 nm / 800 nm) on the absolute X-ray yields has been found. Moreover, we have observed a saturation of the X-ray emission probability below a critical cluster size. (author)

  10. Nuclear deformation in the configuration-interaction shell model

    Science.gov (United States)

    Alhassid, Y.; Bertsch, G. F.; Gilbreth, C. N.; Mustonen, M. T.

    2018-02-01

    We review a method that we recently introduced to calculate the finite-temperature distribution of the axial quadrupole operator in the laboratory frame using the auxiliary-field Monte Carlo technique in the framework of the configuration-interaction shell model. We also discuss recent work to determine the probability distribution of the quadrupole shape tensor as a function of intrinsic deformation β,γ by expanding its logarithm in quadrupole invariants. We demonstrate our method for an isotope chain of samarium nuclei whose ground states describe a crossover from spherical to deformed shapes.

  11. Searches for T-odd interactions in nuclear processes: Review of the theory

    International Nuclear Information System (INIS)

    Herczeg, P.

    1995-01-01

    CP-violation has been seen so far only in the neutral kaon system. Its origin is still unknown. If the CPT theorem holds, as is the case in gauge theories, CP-violating interactions violate also time reversal (T) invariance. Regarding the CPT theorem there is some experimental evidence that the interaction responsible for the observed CP-violation violates T-invariance. The observed CP-violation may just be a manifestation of the weak interaction of the Standard Model (SM), or it is due to an interaction beyond the SM. In both cases some of the new interactions may give rise to observable CP-violation where the SM contribution is invisible. This underlines the importance of searching for CP-violating and T-violating effects in many processes. In this talk we shall review what has been learned about T-violating interactions that can be probed in nuclear processes from experiments outside of and within nuclear physics, and consider the role of nuclear physics experiments in obtaining further information on such interactions

  12. NUCLEAR CHEMISTRY ANNUAL REPORT 1970

    Energy Technology Data Exchange (ETDEWEB)

    Authors, Various

    1971-05-01

    Papers are presented for the following topics: (1) Nuclear Structure and Nuclear Properties - (a) Nuclear Spectroscopy and Radioactivity; (b) Nuclear Reactions and Scattering; (c) Nuclear Theory; and (d) Fission. (2) Chemical and Atomic Physics - (a) Atomic and Molecular Spectroscopy; and (b) Hyperfine Interactions. (3) Physical, Inorganic, and Analytical Chemistry - (a) X-Ray Crystallography; (b) Physical and Inorganic Chemistry; (c) Radiation Chemistry; and (d) Chemical Engineering. (4) Instrumentation and Systems Development.

  13. Estimation of nuclear destruction in high energy nucleus-nucleus interactions

    International Nuclear Information System (INIS)

    Uzhinskij, V.V.

    1995-01-01

    It is assumed that: 1) a projectile particle invokes into target nucleus a cascade of quark-gluon exchanges; 2) the nucleons involved in the cascade are ejected from the nucleus which leads to the nuclear destruction. On these bases a simple model to estimate the nuclear destruction at the fast stage of the interaction is proposed. The allowed region of the model parameters is determined at the proton-emulsion high-energy interaction data analysis: an analysis of gold interactions with nuclei at an energy of 600 MeV/nucleon fixes the parameter values. The distributions on the energy in zero degree calorimeter (T ZDC ) in the interactions of Si+Al, Cu, Pb (14 GeV/nucleon) and Au+Au (10 GeV/nucleon) calculated in the framework of the model and in the cascade-evaporation model (CEM) are presented. The proposed model describes the nuclear destruction at intermediate and high energies better than CEM does. The estimation of the average values of impact parameter and the number of intra-nuclear collisions for Au+Au interactions in the events with different T ZDC is given. 34 refs., 11 figs

  14. Nuclear thermal rocket plume interactions with spacecraft. Final report

    International Nuclear Information System (INIS)

    Mauk, B.H.; Gatsonis, N.A.; Buzby, J.; Yin, X.

    1997-01-01

    This is the first study that has treated the Nuclear Thermal Rocket (NTR) effluent problem in its entirety, beginning with the reactor core, through the nozzle flow, to the plume backflow. The summary of major accomplishments is given below: (1) Determined the NTR effluents that include neutral, ionized and radioactive species, under typical NTR chamber conditions. Applied an NTR chamber chemistry model that includes conditions and used nozzle geometries and chamber conditions typical of NTR configurations. (2) Performed NTR nozzle flow simulations using a Navier-Stokes solver. We assumed frozen chemistry at the chamber conditions and used nozzle geometries and chamber conditions typical of NTR configurations. (3) Performed plume simulations using a Direct Simulation Monte Carlo (DSMC) code with chemistry. In order to account for radioactive trace species that may be important for contamination purposes we developed a multi-weighted DSMC methodology. The domain in our simulations included large regions downstream and upstream of the exit. Inputs were taken from the Navier-Stokes solutions

  15. Intensity of the absorbing dose of the gamma rays in the air of Krusevac during and after nuclear accident in Chernobil

    International Nuclear Information System (INIS)

    Fortuna, D.

    1997-01-01

    In this paper are compared overage daily values of the intensity of the absorbing doses of the gamma rays in the air of Krusevac, during and after nuclear accident in Cernobil. Average daily values of intensity of the absorbing doses of gamma rays in the air of Krusevac, immediately after nuclear accident in Cernobil were, three to seven time higher than of the average daily values of the natural rays. (author)

  16. STAR-JET INTERACTIONS AND GAMMA-RAY OUTBURSTS FROM 3C454.3

    Energy Technology Data Exchange (ETDEWEB)

    Khangulyan, D. V. [Institute of Space and Astronautical Science/JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Barkov, M. V. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Bosch-Ramon, V. [Departament d' Astronomia i Meteorologia, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona (IEEC-UB), Marti i Franques 1, E-08028 Barcelona (Spain); Aharonian, F. A. [Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland); Dorodnitsyn, A. V. [Laboratory for High Energy Astrophysics, NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)

    2013-09-10

    We propose a model to explain the ultra-bright GeV gamma-ray flares observed from the blazar 3C454.3. The model is based on the concept of a relativistic jet interacting with compact gas condensations produced when a star (a red giant) crosses the jet close to the central black hole. The study includes an analytical treatment of the evolution of the envelope lost by the star within the jet, and calculations of the related high-energy radiation. The model readily explains the day-long that varies on timescales of hours, GeV gamma-ray flare from 3C454.3, observed during 2010 November on top of a plateau lasting weeks. In the proposed scenario, the plateau state is caused by a strong wind generated by the heating of the stellar atmosphere due to nonthermal particles accelerated at the jet-star interaction region. The flare itself could be produced by a few clouds of matter lost by the red giant after the initial impact of the jet. In the framework of the proposed scenario, the observations constrain the key model parameters of the source, including the mass of the central black hole: M{sub BH} {approx_equal} 10{sup 9} M{sub Sun }, the total jet power: L{sub j} {approx_equal} 10{sup 48} erg s{sup -1}, and the Doppler factor of the gamma-ray emitting clouds: {delta} {approx_equal} 20. Whereas we do not specify the particle acceleration mechanisms, the potential gamma-ray production processes are discussed and compared in the context of the proposed model. We argue that synchrotron radiation of protons has certain advantages compared to other radiation channels of directlyaccelerated electrons. An injected proton distribution {proportional_to}E {sup -1} or harder below the relevant energies would be favored to alleviate the tight energetic constraints and to avoid the violation of the observational low-energy constraints.

  17. Use of Second Life for interactive instruction and distance learning in nuclear physics and technology

    Science.gov (United States)

    Amme, Robert C.

    2009-05-01

    The developing nuclear power renaissance, coupled with related environmental consequences, is forcing a re-examination of the manner in which nuclear science and technology is (or is not) being taught in the United States. The 20-year hiatus of the nuclear power industry has been a decided factor in the relatively stagnant growth of nuclear physics and nuclear technology instruction, from middle school to graduate education. Furthermore, the general public remains fairly ignorant of the various features of nuclear power, at best having been briefly exposed to the subject only in a middle-school course in Physical Science. Essential to this renaissance is the capacity to deal with the regulatory environment and safety standards that must be addressed prior to new plant certification. Regrettably, too few individuals who are trained in environmental science are adequately prepared in the basic concepts of nuclear physics to deal with such issues as radioactive waste storage and transportation, biological effects of ionizing radiation, geological repositories, nuclear fuel reprocessing, etc. which are of great concern to the Nuclear Regulatory Commission. We are developing a master's degree, to be taught online, in the area of environmental impact assessment as it relates to these and other issues. To accommodate the need for laboratory exercises, we have adopted the virtual world developed by Linden Laboratory entitled Second Life; it is here that the student, as an avatar, will gain knowledge of the nature of ionizing radiation, radioactive half-lives, gamma and beta ray spectroscopy, neutron activation, and radiation shielding, using virtual apparatus and virtual radiation sources. Additionally, a virtual Generation III+ power reactor has been constructed on an adjoining Second Life island (entitled Science School II) which provides the visitor with a realistic impression of its inner workings. This presentation will provide the details of this construct and how it

  18. Semihard interactions in nuclear collisions based on a unified approach to high energy scattering

    International Nuclear Information System (INIS)

    Drescher, H.J.; Hladik, M.; Werner, K.; Ostapchenko, S.; Centre National de la Recherche Scientifique, 44 - Nantes

    1998-01-01

    Our ultimate goal is the construction of a model for interactions of two nuclei in the energy range between several tens of GeV up to several TeV per nucleon in the centre-of-mass system. Such nuclear collisions are very complex, being composed of many components, and therefore some strategy is needed to construct a reliable model. The central point of our approach is the hypothesis, that the behavior of high energy interactions is universal (universality hypothesis). A model for nuclear interactions in a modular fashion is proposed. The individual modules, based on the universality hypothesis, are identified as building blocks for more elementary interactions (like e + e - , lepton-proton), and can therefore be studied in a much simpler context. With these building blocks under control, a quite reliable model is developed for nucleus-nucleus scattering, providing in particular very useful tests for the complicated numerical procedures using Monte Carlo techniques. (author)

  19. Binding energies of hypernuclei and Λ-nuclear interactions

    International Nuclear Information System (INIS)

    Bodmer, A.R.; Usmani, Q.N.

    1985-01-01

    Variational Monte Carlo calculations have been made for the s-shell hypernuclei and also of 9 Be hypernuclei with a 2α + Λ model. The well depth is calculated variationally with the Fermi hypernetted chain method. A satisfactory description of all the relevant experimental Λ separation energies and also of the Λp scattering can be obtained with reasonable TPE ΛN and ΛNN forces and strongly repulsive dispersive ΛNN forces which are preferred to be spin dependent. We discuss variational calculations for 6 He and 10 Be hypernuclei with α + 2Λ and 2α + 2Λ models, and the results obtained for the ΛΛ interaction and for 6 He hypernuclei from analysis of 10 Be hypernuclei Coulomb effects and charge symmetry breaking in the A = 4 hypernuclei are discussed. 24 refs., 5 figs

  20. Binding energies of hypernuclei and. lambda. -nuclear interactions

    Energy Technology Data Exchange (ETDEWEB)

    Bodmer, A.R.; Usmani, Q.N.

    1985-01-01

    Variational Monte Carlo calculations have been made for the s-shell hypernuclei and also of /sup 9/Be hypernuclei with a 2..cap alpha.. + ..lambda.. model. The well depth is calculated variationally with the Fermi hypernetted chain method. A satisfactory description of all the relevant experimental ..lambda.. separation energies and also of the ..lambda..p scattering can be obtained with reasonable TPE ..lambda..N and ..lambda..NN forces and strongly repulsive dispersive ..lambda..NN forces which are preferred to be spin dependent. We discuss variational calculations for /sup 6/He and /sup 10/Be hypernuclei with ..cap alpha.. + 2..lambda.. and 2..cap alpha.. + 2..lambda.. models, and the results obtained for the ..lambda lambda.. interaction and for /sup 6/He hypernuclei from analysis of /sup 10/Be hypernuclei Coulomb effects and charge symmetry breaking in the A = 4 hypernuclei are discussed. 24 refs., 5 figs.

  1. Nuclear weak interactions, supernova nucleosynthesis and neutrino oscillation

    Science.gov (United States)

    Kajino, Toshitaka

    2013-07-01

    We study the nuclear weak response in light-to-heavy mass nuclei and calculate neutrino-nucleus cross sections. We apply these cross sections to the explosive nucleosynthesis in core-collapse supernovae and find that several isotopes of rare elements 7Li, 11B, 138La, 180Ta and several others are predominantly produced by the neutrino-process nucleosynthesis. We discuss how to determine the suitable neutrino spectra of three different flavors and their anti-particles in order to explain the observed solar system abundances of these isotopes, combined with Galactic chemical evolution of the light nuclei and the heavy r-process elements. Light-mass nuclei like 7Li and 11B, which are produced in outer He-layer, are strongly affected by the neutrino flavor oscillation due to the MSW (Mikheyev-Smirnov-Wolfenstein) effect, while heavy-mass nuclei like 138La, 180Ta and r-process elements, which are produced in the inner O-Ne-Mg layer or the atmosphere of proto-neutron star, are likely to be free from the MSW effect. Using such a different nature of the neutrino-process nucleosynthesis, we study the neutrino oscillation effects on their abundances, and propose a new novel method to determine the unknown neutrino oscillation parameters, θ13 and mass hierarchy, simultaneously. There is recent evidence that some SiC X grains from the Murchison meteorite may contain supernova-produced neutrino-process 11B and 7Li encapsulated in the grains. Combining the recent experimental constraints on θ13, we show that although the uncertainties are still large, our method hints at a marginal preference for an inverted neutrino mass hierarchy for the first time.

  2. Automated system for processing nuclear emulsion data on nuclear-nuclear interactions for EMU-15 CERN experiment

    International Nuclear Information System (INIS)

    Aleksandrov, A.B.; Azarenkova, I.Yu.; Feinberg, E.L.; Goneharova, L.A.; Martynov, A.G.; Polukhina, N.G.; Starkov, N.I.

    2004-01-01

    The EMU-15 experiment has been performed at CERN by the LPI group with the aim of studying characteristics of high-density and high-temperature nuclear matter, in particular, for searching for manifestation of quark-gluon plasma. The main problem inherent in these investigations is a large amount of track measurements in nuclear emulsions. A very efficient Completely Automated Measuring Complex (Russian abbreviation sounds as P AVICOM ) for track-detector data processing in nuclear and high-energy particle physics is operating at the Lebedev Physical Institute. The PAVICOM provides essential improving the efficiency of experimental studies performed not only by the LPI group, but also by many Russian Institutes

  3. Nuclear structure with unitarily transformed two-body plus phenomenological three-body interactions

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Anneke

    2011-02-02

    The importance of three-nucleon forces for a variety of nuclear structure phenomena is apparent in various investigations. This thesis provides a first step towards the inclusion of realistic three-nucleon forces by studying simple phenomenological threebody interactions. The Unitary Correlation Operator Method (UCOM) and the Similarity Renormalization Group (SRG) provide two different approaches to derive soft phase-shift equivalent nucleon-nucleon (NN) interactions via unitary transformations. Although their motivations are quite different the NN interactions obtained with the two methods exhibit some similarities. The application of the UCOM- or SRG-transformed Argonne V18 potential in the Hartree-Fock (HF) approximation and including the second-order energy corrections emerging from many-body perturbation theory (MBPT) reveals that the systematics of experimental ground-state energies can be reproduced by some of the interactions considering a series of closed-shell nuclei across the whole nuclear chart. However, charge radii are systematically underestimated, especially for intermediate and heavy nuclei. This discrepancy to experimental data is expected to result from neglected three-nucleon interactions. As first ansatz for a three-nucleon force, we consider a finite-range three-body interaction of Gaussian shape. Its influence on ground-state energies and charge radii is discussed in detail on the basis of HF plus MBPT calculations and shows a significant improvement in the description of experimental data. As the handling of the Gaussian three-body interaction is time-extensive, we show that it can be replaced by a regularized three-body contact interaction exhibiting a very similar behavior. An extensive study characterizes its properties in detail and confirms the improvements with respect to nuclear properties. To take into account information of an exact numerical solution of the nuclear eigenvalue problem, the No-Core Shell Model is applied to

  4. Mutagenic interactions between maleic hydrazide and X rays in the stamen hairs of Tradescantia clone BNL 4430

    International Nuclear Information System (INIS)

    Xiao, Ling-Zhi; Ichikawa, Sadao

    1995-01-01

    Mutagenic interactions between maleic hydrazide (MH; a promutagen known to be activated into a mutagen in plant cells) and X rays were studied in the stamen hairs of Tradescantia clone BNL 4430, a blue/pink heterozygote. The young inflorescence-bearing shoots with roots cultivated in the nutrient solution circulating growth chamber were used as tester plants. After determining dose-response curves for X rays and for MH, nine combined treatments with MH (0.5 and 1 mM) and X rays (292 to 1,240 mGy) were conducted, exposing to X rays either 20 or 44 h before, at the midpoint of, or 2 or 44 h after the MH treatments for 4h. Clear synergistic effects in inducing somatic pink mutations were detected when X rays were given before the MH treatments. On the contrary, however, antagonistic effects were often observed when X-ray treatments were carried out during or after the MH treatments. The synergistic effects detected were thought to be the results of interactions between DNA strand breaks (and the resultant chromosomal breaks) induced by X rays and those by MH, whereas the antagonistic effects observed were presumed to have resulted from X-ray-caused inhibition of the activation of MH in the stamen-hair cells. (author)

  5. A sensitivity study of seismic structure-soil-structure interaction problems for nuclear power plants

    International Nuclear Information System (INIS)

    Matthees, W.; Magiera, G.

    1982-01-01

    A sensitivity study for the interaction effects of adjacent structures of nuclear power plants caused by horizontal seismic excitation has been performed. The key structural and soil parameters for linear and for nonlinear behaviour were varied within their applicable bandwidth. It has been shown that the interaction phenomena can contribute to the response of structures to such a large extent that it cannot be disregarded. (orig.)

  6. Interactive and automated systems for nuclear track measurements with applications to fast neutron dosimetry

    International Nuclear Information System (INIS)

    Roberts, J.H.; Gold, R.; McNeece, J.P.; Preston, C.C.; Ruddy, F.H.

    1983-12-01

    Interactive and automatic track measuring systems have been developed primarily for fast neutron dosimetry in and around reactors. The interactive system is used for proton recoil measurements in nuclear research emulsions and the automatic systems for counting fission fragment tracks in Muscovite mica. The status of these systems, along with illustrative applications, are presented, particularly with regard to their relationship to neutron personnel dosimetry. 16 references, 12 figures

  7. Nuclear quadrupole-quadrupole interaction in the inelastic scattering of aligned deuterons from deformed nuclei

    International Nuclear Information System (INIS)

    Clement, H.; Frick, R.; Graw, G.; Schiemenz, P.; Seichert, N.

    1983-01-01

    The 2 1 + -excitation of deformed nuclei by tensor polarized deuterons provides an alignment of both nuclei and thus a means to study specifically the quadrupole-quadrupole interaction between both nuclei. The tensor analyzing power Asub(xz)(theta) has been measured for the elastic and inelastic scattering on 24 Mg and 28 Si. The coupled channel analysis including a deformed tensor potential reveals a clear signature of the quadrupole-quadrupole part of the nuclear projectile-target interaction. (orig.)

  8. High-Energy X-Ray Imaging Applied to Nondestructive Characterization of Large Nuclear Waste Drums

    Science.gov (United States)

    Estre, Nicolas; Eck, Daniel; Pettier, Jean-Luc; Payan, Emmanuel; Roure, Christophe; Simon, Eric

    2015-12-01

    As part of its R&D programs on non-destructive testing of nuclear waste drums, CEA is commissioning an irradiation cell named CINPHONIE, at Cadarache. This cell allows high-energy imaging (radiography and tomography) on large volumes (up to 5 m3) and heavy weights (up to 5 tons). A demonstrator has been finalized, based on existing components. The X-ray source is a 9 MeV LINAC which produces Bremsstrahlung X-rays (up to 23 Gy/min at 1 meter in the beam axis). The mechanical bench is digitally controlled on three axes (translation, rotation, elevation) and can handle objects up to 2 t. This bench performs trajectories necessary for acquisition of projections (sinograms) according to different geometries: Translation-Rotation, Fan-Beam and Cone-Beam. Two detection systems both developed by CEA-Leti are available. The first one is a large GADOX scintillating screen ( 800 ×600 mm2) coupled to a low-noise pixelated camera. The second one is a multi-CdTe semiconductor detector, offering measurements up to 5 decades of attenuation (equivalent to 25 cm of lead or 180 cm of standard concrete). At the end of the acquisition, a Filtered Back Projection-based algorithm is performed. Then, a density slice (fan-beam tomography) or a density volume (cone-beam tomography or helical tomography) is produced and used to examine the waste. Characterization of LINAC, associated detectors as well as the full acquisition chain, are presented. Experimental performances on phantoms and real drum are discussed and expected limits on defect detectability are evaluated by simulation. The final system, designed to handle objects up to 5 tons is then presented.

  9. 3D gamma-ray imaging systems in nuclear medicine and collimator purposes

    International Nuclear Information System (INIS)

    Strocovsky, S.G.; Otero, D.

    2013-01-01

    Single photon gamma-ray imaging systems, currently used in Nuclear Medicine, are fundamentally based on the Gamma Camera (CG) and their associated SPECT technique. The modern CG presents no essential changes in the method used to form the image compared to the camera designed by H. O. Anger (Pat US 3.011.057, 1961).The current CG, as well as the proposed by Anger, uses a collimator for the formation of images. However, this element imposes a severe limit on the maximum attainable spatial resolution and dramatically decreases the sensitivity of the whole system. As a result, CG images are, generally, low quality with high Poisson noise. On the other hand, Strocovsky, S. and D. Otero, have presented the principles of a new technique, called Full Aperture Imaging (FAI) based on a novel coded imaging technique and differential detection. FAI does not use a collimator and outperforms the CG, in sensitivity and spatial resolution. In addition, FAI allows to register 3D information in a single acquisition, while SPECT requires sequential acquisition of images for the same purpose. In this paper, a review of the gamma-ray imaging systems developed to the present is made. Several types of SPECT systems, coded imaging systems, diffractive lenses, Compton camera, multiple no-planar detectors/collimators modules and the new FAI system are included. The role of collimators in the formation of CG images is critically examined and compared to the method used in FAI. Simulated Monte Carlo Images that allow to compare CG versus FAI in identical conditions are shown. We propose a novel use of collimators in FAI, for reduction of the field of view, with 100% collection efficiency. FAI is based on data-intensive computing and in proven conventional planar detectors of CG technology, so FAI surpasses the other described systems in the combination of sensitivity, spatial resolution, 3D information acquisition, and simplicity of design. (author)

  10. Experiments on the nuclear interactions of pions and electrons

    International Nuclear Information System (INIS)

    Minehart, R.C.; Ziock, K.O.H.

    1989-07-01

    We have completed the analysis of the 3 He(π + ,pp)n reaction, and are working on the analysis of data for the 3 He(π - ,pn)p reaction. An experiment to study the π + d → 2p reaction at LAMPF was successful in studying incident pion energies as low as 6 MeV. Preliminary results have been reported, and work is continuing to improve the accuracy in the calculation of the fraction of pions in the incident beam. A proposal has been accepted by LAMPF for a new experiment, scheduled to run in the summer of 1990, to study pion absorption in 3 He and 4 He using an extensive scintillator time-of-flight system capable of detecting neutrons as well as charged particles. We are continuing to analyze data obtained in PSI in the search for the admixture of massive neutrinos in pion decay and have continued the search for fractionally charged particles. We are also fully involved in some major collaborations: the search for the decay μ + → e + + γ, and the study of anti-proton absorption in heavy nuclei. We are taking part in a U.Va.-PSI collaboration to measure pion beta decay to an accuracy of about 1%, using a large acceptance CsI detector to measure the π 0 following decay of stopped π + mesons. We have also been working on experiments to study electron scattering, using the SLAC-NPAS facility for nuclear physics and the electron accelerator at SACLAY in France. Data from experiment NE-9 at SLAC are being analyzed. This experiment, which was run near the end of 1987, is intended to separate the transverse and longitudinal cross sections for inclusive electron scattering in the QFS region. Experiment NE-8 measured the cross section for photo-disintegration of the deuteron in the GeV range. Some design work was carried out this year on Experiment NE-16 at SLAC, a study of the (e,e'p) reaction in 4 He, expected to run late in 1990

  11. Quantitative x-ray diffraction analyses of samples used for sorption studies by the Isotope and Nuclear Chemistry Division, Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Chipera, S.J.; Bish, D.L.

    1989-09-01

    Yucca Mountain, Nevada, is currently being investigated to determine its suitability to host our nation's first geologic high-level nuclear waste repository. As part of an effort to determine how radionuclides will interact with rocks at Yucca Mountain, the Isotope and Nuclear Chemistry (INC) Division of Los Alamos National Laboratory has conducted numerous batch sorption experiments using core samples from Yucca Mountain. In order to understand better the interaction between the rocks and radionuclides, we have analyzed the samples used by INC with quantitative x-ray diffraction methods. Our analytical methods accurately determine the presence or absence of major phases, but we have not identified phases present below ∼1 wt %. These results should aid in understanding and predicting the potential interactions between radionuclides and the rocks at Yucca Mountain, although the mineralogic complexity of the samples and the lack of information on trace phases suggest that pure mineral studies may be necessary for a more complete understanding. 12 refs., 1 fig., 1 tab

  12. Gamma-ray burst jet dynamics and their interaction with the progenitor star.

    Science.gov (United States)

    Lazzati, Davide; Morsony, Brian J; Begelman, Mitchell C

    2007-05-15

    The association of at least some long gamma-ray bursts with type Ic supernova explosions has been established beyond reasonable doubt. Theoretically, the challenge is to explain the presence of a light hyper-relativistic flow propagating through a massive stellar core without losing those properties. We discuss the role of the jet-star interaction in shaping the properties of the outflow emerging on the surface of the star. We show that the nature of the inner engine is hidden from the observer for most of the evolution, well beyond the time of the jet breakout on the stellar surface. The discussion is based on analytical considerations as well as high resolution numerical simulations. Finally, the observational consequences of the scenario are addressed in light of the present capabilities.

  13. Ray tracing method for simulation of laser beam interaction with random packings of powders

    Science.gov (United States)

    Kovalev, O. B.; Kovaleva, I. O.; Belyaev, V. V.

    2018-03-01

    Selective laser sintering is a technology of rapid manufacturing of a free form that is created as a solid object by selectively fusing successive layers of powder using a laser. The motivation of this study is due to the currently insufficient understanding of the processes and phenomena of selective laser melting of powders whose time scales differ by orders of magnitude. To construct random packings from mono- and polydispersed solid spheres, the algorithm of their generation based on the discrete element method is used. A numerical method of ray tracing is proposed that is used to simulate the interaction of laser radiation with a random bulk packing of spherical particles and to predict the optical properties of the granular layer, the extinction and absorption coefficients, depending on the optical properties of a powder material.

  14. Search for a Signature of Interaction between Relativistic Jet and Progenitor in Gamma-Ray Bursts

    Science.gov (United States)

    Yoshida, Kazuki; Yoneoku, Daisuke; Sawano, Tatsuya; Ito, Hirotaka; Matsumoto, Jin; Nagataki, Shigehiro

    2017-11-01

    The time variability of prompt emission in gamma-ray bursts (GRBs) is expected to originate from the temporal behavior of the central engine activity and the jet propagation in the massive stellar envelope. Using a pulse search algorithm for bright GRBs, we investigate the time variability of gamma-ray light curves to search a signature of the interaction between the jet and the inner structure of the progenitor. Since this signature might appear in the earlier phase of prompt emission, we divide the light curves into the initial phase and the late phase by referring to the trigger time and the burst duration of each GRB. We also adopt this algorithm for GRBs associated with supernovae/hypernovae that certainly are accompanied by massive stars. However, there is no difference between each pulse interval distribution described by a lognorma distribution in the two phases. We confirm that this result can be explained by the photospheric emission model if the energy injection of the central engine is not steady or completely periodic but episodic and described by the lognormal distribution with a mean of ˜1 s.

  15. Search for a Signature of Interaction between Relativistic Jet and Progenitor in Gamma-Ray Bursts

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Kazuki; Yoneoku, Daisuke; Sawano, Tatsuya [College of Science and Engineering, School of Mathematics and Physics, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192 (Japan); Ito, Hirotaka; Matsumoto, Jin; Nagataki, Shigehiro, E-mail: yoshida@astro.s.kanazawa-u.ac.jp, E-mail: yonetoku@astro.s.kanazawa-u.ac.jp [Astrophysical Big Ban Laboratory, RIKEN, Saitama 351-0198 (Japan)

    2017-11-01

    The time variability of prompt emission in gamma-ray bursts (GRBs) is expected to originate from the temporal behavior of the central engine activity and the jet propagation in the massive stellar envelope. Using a pulse search algorithm for bright GRBs, we investigate the time variability of gamma-ray light curves to search a signature of the interaction between the jet and the inner structure of the progenitor. Since this signature might appear in the earlier phase of prompt emission, we divide the light curves into the initial phase and the late phase by referring to the trigger time and the burst duration of each GRB. We also adopt this algorithm for GRBs associated with supernovae/hypernovae that certainly are accompanied by massive stars. However, there is no difference between each pulse interval distribution described by a lognorma distribution in the two phases. We confirm that this result can be explained by the photospheric emission model if the energy injection of the central engine is not steady or completely periodic but episodic and described by the lognormal distribution with a mean of ∼1 s.

  16. GALACTIC COSMIC-RAY INTENSITY MODULATION BY COROTATING INTERACTION REGION STREAM INTERFACES AT 1 au

    Energy Technology Data Exchange (ETDEWEB)

    Guo, X. [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing, 100190 (China); Florinski, V. [Center for Space Plasma and Aeronomic Research, University of Alabama, Huntsville, AL 35899 (United States)

    2016-07-20

    We present a new model that couples galactic cosmic-ray (GCR) propagation with magnetic turbulence transport and the MHD background evolution in the heliosphere. The model is applied to the problem of the formation of corotating interaction regions (CIRs) during the last solar minimum from the period between 2007 and 2009. The numerical model simultaneously calculates the large-scale supersonic solar wind properties and its small-scale turbulent content from 0.3 au to the termination shock. Cosmic rays are then transported through the background, and thus computed, with diffusion coefficients derived from the solar wind turbulent properties, using a stochastic Parker approach. Our results demonstrate that GCR variations depend on the ratio of diffusion coefficients in the fast and slow solar winds. Stream interfaces inside the CIRs always lead to depressions of the GCR intensity. On the other hand, heliospheric current sheet (HCS) crossings do not appreciably affect GCR intensities in the model, which is consistent with the two observations under quiet solar wind conditions. Therefore, variations in diffusion coefficients associated with CIR stream interfaces are more important for GCR propagation than the drift effects of the HCS during a negative solar minimum.

  17. GALACTIC COSMIC-RAY INTENSITY MODULATION BY COROTATING INTERACTION REGION STREAM INTERFACES AT 1 au

    International Nuclear Information System (INIS)

    Guo, X.; Florinski, V.

    2016-01-01

    We present a new model that couples galactic cosmic-ray (GCR) propagation with magnetic turbulence transport and the MHD background evolution in the heliosphere. The model is applied to the problem of the formation of corotating interaction regions (CIRs) during the last solar minimum from the period between 2007 and 2009. The numerical model simultaneously calculates the large-scale supersonic solar wind properties and its small-scale turbulent content from 0.3 au to the termination shock. Cosmic rays are then transported through the background, and thus computed, with diffusion coefficients derived from the solar wind turbulent properties, using a stochastic Parker approach. Our results demonstrate that GCR variations depend on the ratio of diffusion coefficients in the fast and slow solar winds. Stream interfaces inside the CIRs always lead to depressions of the GCR intensity. On the other hand, heliospheric current sheet (HCS) crossings do not appreciably affect GCR intensities in the model, which is consistent with the two observations under quiet solar wind conditions. Therefore, variations in diffusion coefficients associated with CIR stream interfaces are more important for GCR propagation than the drift effects of the HCS during a negative solar minimum.

  18. Cosmic-Ray Transport in Heliospheric Magnetic Structures. II. Modeling Particle Transport through Corotating Interaction Regions

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, Andreas [Université Libre de Bruxelles, Service de Physique Statistique et des Plasmas, CP 231, B-1050 Brussels (Belgium); Wiengarten, Tobias; Fichtner, Horst [Institut für Theoretische Physik IV, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Effenberger, Frederic [Department of Physics and KIPAC, Stanford University, Stanford, CA 94305 (United States); Kühl, Patrick; Heber, Bernd [Institut für Experimentelle und Angewandte Physik, Christian-Albrecht-Universität zu Kiel, D-24098 Kiel (Germany); Raath, Jan-Louis; Potgieter, Marius S. [Centre for Space Research, North-West University, 2520 Potchefstroom (South Africa)

    2017-03-01

    The transport of cosmic rays (CRs) in the heliosphere is determined by the properties of the solar wind plasma. The heliospheric plasma environment has been probed by spacecraft for decades and provides a unique opportunity for testing transport theories. Of particular interest for the three-dimensional (3D) heliospheric CR transport are structures such as corotating interaction regions (CIRs), which, due to the enhancement of the magnetic field strength and magnetic fluctuations within and due to the associated shocks as well as stream interfaces, do influence the CR diffusion and drift. In a three-fold series of papers, we investigate these effects by modeling inner-heliospheric solar wind conditions with the numerical magnetohydrodynamic (MHD) framework Cronos (Wiengarten et al., referred as Paper I), and the results serve as input to a transport code employing a stochastic differential equation approach (this paper). While, in Paper I, we presented results from 3D simulations with Cronos, the MHD output is now taken as an input to the CR transport modeling. We discuss the diffusion and drift behavior of Galactic cosmic rays using the example of different theories, and study the effects of CIRs on these transport processes. In particular, we point out the wide range of possible particle fluxes at a given point in space resulting from these different theories. The restriction of this variety by fitting the numerical results to spacecraft data will be the subject of the third paper of this series.

  19. Compact X-ray sources. Simulating the electron/strong laser interaction

    Energy Technology Data Exchange (ETDEWEB)

    Hartin, Anthony [DESY, CFEL, Hamburg (Germany)

    2016-07-01

    The collision of an intense laser with an electron bunch can be used to produce X-rays via the inverse Compton scattering (ICS) mechanism. The ICS can be simulated via either a classical theory in which electrons and photons are treated in terms of classical electromagnetic waves - or a quantum theory in which charged particles interact with strong electromagnetic fields. The laser intensity used in a practical ICS collision is likely to be at such a level that quantum effects may be significant and the use of quantum theory may become a necessity. A simulation study is presented here comparing the classical and quantum approaches to the ICS. A custom particle-in-cell (PIC) software code, with photon generation by monte carlo of the exact quantum transition probability is used to simulate the quantum treatment. Peak resonant energies and the angular distribution of the X-rays are obtained and compared with those predicted by the classical theory. The conditions under which significant differences between the two theories emerges is obtained.

  20. Interactions between nuclear polyhedrosis virus and Nosema sp. infecting gypsy moth

    Science.gov (United States)

    L. S. Bauer; M. McManus; J. Maddox

    1991-01-01

    Nuclear polyhedrosis virus (NPV) is the only entomopathogen that plays an important role in the natural regulation of North American gypsy moth populations. Recent European studies suggest that populations of gypsy moth in Eurasia are regulated primarily by the interactions between NPV and several species of microsporidia. Researchers have proposed that the...

  1. Nuclear interaction contribution to SEUs in heavy ion energy deposition in the ESA monitor

    CERN Document Server

    Bahamonde, Cristina

    2013-01-01

    The effects of nuclear interactions inducing Single Event Upsets in ESA SEU monitor are explored for heavy ion beams of different energies. The experimental and simulated results are compared, the possible causes of disagreement are suggested as well as the future steps to take.

  2. The Insulator Protein SU(HW) Fine-Tunes Nuclear Lamina Interactions of the Drosophila Genome

    NARCIS (Netherlands)

    Van Bemmel, J.G.; Pagie, L.; Braunschweig, U.; Brugman, W.; Meuleman, W.; Kerkhoven, R.M.; Van Steensel, B.

    2010-01-01

    Specific interactions of the genome with the nuclear lamina (NL) are thought to assist chromosome folding inside the nucleus and to contribute to the regulation of gene expression. High-resolution mapping has recently identified hundreds of large, sharply defined lamina-associated domains (LADs) in

  3. Secondary phases formed during nuclear waste glass-water interactions: Thermodynamic and derived properties

    International Nuclear Information System (INIS)

    McKenzie, W.F.

    1992-08-01

    The thermodynamic properties of secondary phases observed to form during nuclear waste glass-water interactions are of particular interest as it is with the application of these properties together with the thermodynamic properties of other solid phases, fluid phases, and aqueous species that one may predict the environmental consequences of introducing radionuclides contained in the glass into groundwater at a high-level nuclear waste repository. The validation of these predicted consequences can be obtained from laboratory experiments and field observations at natural analogue sites. The purpose of this report is to update and expand the previous compilation (McKenzie, 1991) of thermodynamic data retrieved from the literature and/or estimated for secondary phases observed to form (and candidate phases from observed chemical compositions) during nuclear waste glass-water interactions. In addition, this report includes provisionally recommended thermodynamic data of secondary phases

  4. Nuclear chemistry progress report

    International Nuclear Information System (INIS)

    1976-01-01

    A brief administrative review is given of work in the following areas: investigations of the chemical effects accompanying muon capture in atoms and molecules, quadrupole interaction in metal and semimetal systems using perturbed gamma-ray angular correlation, and nuclear structure research using nuclear reaction spectroscopy. Detailed research reports were published in appropriate places; a publication list is included. 2 figures

  5. Study of plasmas created by X-ray laser-matter interaction

    International Nuclear Information System (INIS)

    Galtier, E.

    2010-11-01

    This thesis took advantage of the emerging newly developed 4. generation sources of light, namely the free electron lasers, to create and characterize a state of matter under extreme conditions which is still obscure: the warm dense matter (WDM). WDM is found in giant planets and is also produced in inertial fusion. An experiment allowed to study the transitions between the different phases, solid/WDM/plasma, and characterize the mechanism responsible for the equilibration. The laser pulse FLASH, of duration and energy equal to about 20 femto-seconds and 30 μJ respectively, is micro-focussed on a solid target producing an isochoric heating. The intensity, greater than 10 16 W.cm -2 , has never been reached in such an experimental context so far. Emission spectra from an aluminium plasma are studied with a code coupling a genetic algorithm and a code of atomic physics, in order to interpret the whole temporal evolution of the XUV laser-matter interaction for the first time, despite the time integration of the experimental spectra. The first experimental proof of the important contribution of the Auger effect in the isochoric heating of an aluminium target is established. The first observation of the X-ray emission of a boron nitride target under extreme conditions has been investigated by a preliminary study. Additionally, the effect of hot electrons on the electron population distribution in the energy levels of the ions is analysed and shows an important similarity with the photo-ionization process occurring in XUV/X-ray laser-matter interaction. (author)

  6. Interaction of femtosecond X-ray pulses with periodical multilayer structures

    International Nuclear Information System (INIS)

    Ksenzov, Dmitry

    2010-01-01

    The VUV Free Electron Laser FLASH operates in soft X-ray range and produces high-intensive pulse trains with few tens femtoseconds duration. The transversely fully coherent beam will open new experiments in solid state physics which can not be studied with present radiation sources. The study of the time dependent response of the multilayer to the X-ray pulse can provide insights into the process of interaction of highly intense FEL radiation with matter. To test the influence of electron excitation on the optical properties of boron carbide, the refractive index of B 4 C was measured near B K-edge by energy-resolved photon-in-photon-out method probing a Bragg reflection from periodical multilayers. The measured data clearly show that the variation of the fine structure of the Kabsorption edges due to the chemical nature of the absorber element. The knowledge obtained from experiments with continuous radiation was used to design the respective experiments with pulse from the FEL. In my thesis, it is proposed that the geometrical setup, where the incident pulse arrives from the FEL under the angle close to the 1st order ML Bragg peak, provides the most valuable information. Preliminary simulation considering form factors of neutral and ionized boron showed that due to ionization, pronounced changes in the reflectivity curve are expected. The proposed scheme can be the powerful tool to study the various processes within the electronic subsystem of the FEL pulse interaction with matter. This type of investigations gives a deep understanding of the nature of the electronic excitation and the recombination at the femtosecond scale. (orig.)

  7. Interaction of femtosecond X-ray pulses with periodical multilayer structures

    Energy Technology Data Exchange (ETDEWEB)

    Ksenzov, Dmitry

    2010-07-01

    The VUV Free Electron Laser FLASH operates in soft X-ray range and produces high-intensive pulse trains with few tens femtoseconds duration. The transversely fully coherent beam will open new experiments in solid state physics which can not be studied with present radiation sources. The study of the time dependent response of the multilayer to the X-ray pulse can provide insights into the process of interaction of highly intense FEL radiation with matter. To test the influence of electron excitation on the optical properties of boron carbide, the refractive index of B{sub 4}C was measured near B K-edge by energy-resolved photon-in-photon-out method probing a Bragg reflection from periodical multilayers. The measured data clearly show that the variation of the fine structure of the Kabsorption edges due to the chemical nature of the absorber element. The knowledge obtained from experiments with continuous radiation was used to design the respective experiments with pulse from the FEL. In my thesis, it is proposed that the geometrical setup, where the incident pulse arrives from the FEL under the angle close to the 1st order ML Bragg peak, provides the most valuable information. Preliminary simulation considering form factors of neutral and ionized boron showed that due to ionization, pronounced changes in the reflectivity curve are expected. The proposed scheme can be the powerful tool to study the various processes within the electronic subsystem of the FEL pulse interaction with matter. This type of investigations gives a deep understanding of the nature of the electronic excitation and the recombination at the femtosecond scale. (orig.)

  8. The interaction of a very large interplanetary magnetic cloud with the magnetosphere and with cosmic rays

    International Nuclear Information System (INIS)

    Lepping, R.P.; Burlaga, L.F.; Ogilvie, K.W.; Tsurutani, B.T.; Lazarus, A.J.; Evans, D.S.; Klein, L.W.

    1991-01-01

    A large interplanetary magnetic cloud has been observed in the mid-December 1982 data from ISEE 3. It is estimated to have a heliocentric radial extent of approx-gt 0.4 AU, making it one of the largest magnetic clouds yet observed at 1 AU. The magnetic field measured throughout the main portion of the cloud was fairly tightly confined to a plane as it changed direction by 174 degree while varying only moderately in magnitude. Throughout nearly the entire duration of the cloud's passage, IMP 8 was located in the Earth's dawn magnetosheath providing observations of this cloud's interaction with the bow shock and magnetopause; the cloud is shown to maintain its solar wind characteristics during the interaction. Near the end of the cloud passage, at 0806 UT on December 17, ISEE 3 (and IMP 8 at nearly the same time) observed an oblique fast forward interplanetary shock closely coincident in time with a geomagnetic storm sudden commencement. The shock, moving much faster than the cloud (radial speeds of 700 and 390 km/s, respectively, on the average), was in the process of overtaking the cloud. The index Dst decreased monotonically by ∼ 130 nT during the 2-day cloud passage by the Earth and was well correlated with the B z component of the interplanetary magnetic field. There was no significant decrease in the cosmic ray intensity recorded by ground-based neutron monitors at this time of rather strong, smoothly changing fields. However, a Forbush decrease did occur immediately after the interplanetary shock, during a period of significant field turbulence. Thus a large, smooth, interplanetary helical magnetic field configuration engulfing the Earth does not necessarily deflect cosmic rays sufficiently to cause a Forbush decrease, but there is a suggestion that such a decrease may be caused by particle scattering by turbulent magnetic fields

  9. Experiments on the nuclear interactions of pions and electrons

    International Nuclear Information System (INIS)

    Minehart, R.C.; Ziock, K.O.H.

    1992-08-01

    The analysis of the deuterium content in the CD target used in an experiment to study the π + d → 2p reaction at incident pion energies from 4 to 20 MeV was completed. The final paper describing this experiment will be submitted for publication this summer. Analysis of LAMPF Exp. on pion absorption in 4 He is continuing. In 1991, we collaborated with D. Pocanic from the Univ. of Virginia on a measurement at LAMPF of the π 0 production in π + p interactions. This run proved the validity of the method and additional data were obtained in a second run during the summer of 1992, using a new target. Current collaborations at LAMPF include the search for the decay μ + → e + + γ(MEGA) and a measurement of the Michel ρ parameter in the decay μ → e + v + v. A U.Va.--PSI collaboration is measuring pion beta decay to an accuracy of less than 1%, using a large acceptance CsI detector to measure the π 0 following decay of stopped π + mesons. Most of the U.Va. effort is devoted to the CEBAF Large Acceptance Spectrometer (CLAS) program to the construction of the CLAS forward calorimeter. An apparatus to measure the properties of the scintillators with light from a N 2 laser was built in the spring of 1992. The electronic circuitry for the energy signal from the EGN detector and the circuitry needed to route the signals from the all the photomultipliers to the TDC and ADC circuits are being developed. Experimental proposals for the study of electroproduction of nucleon resonances at CEBAF, including measurements with polarized beam and targets, are being developed

  10. Practical training in the operation of nuclear power plants with Interactive Graphic Simulator of Zorita

    International Nuclear Information System (INIS)

    Cuervo, D.; Garcia-Herranz, N.; Garcia, S.; Davila, R.; Ahnert, C.; Aragones, J. M.; Cabellos, O.; Gallego, E.; Lorente, A.; Minguez, E.; Rebollo, L.; Blanco, J.

    2010-01-01

    In April 2008 a collaboration agreement was signed between Gas Natural Union Fenosa and the Universad Politecnica de Madrid for the creation of the Aula Jose Cabrera dedicated to train professionals in the field of nuclear technology. The Classroom located in the Department of Nuclear Engineering, has been equipped with the Interactive Graphic Simulator of Zorita (SGIZ). The use of the simulator intended to improve the quality of teaching in the area of Nuclear Engineering. It integrates in the teachings of Industrial Engineering degree and the Master of Nuclear Science and Technology. Different manuals are under preparation to make it a suitable tool for teaching purpose. These manuals will guide the student so that learning takes place both through the guidance of the teacher as independently. (Author) 3 refs.

  11. Delayed gamma-ray spectroscopy with lanthanum bromide detector for non-destructive assay of nuclear material

    Science.gov (United States)

    Favalli, Andrea; Iliev, Metodi; Ianakiev, Kiril; Hunt, Alan W.; Ludewigt, Bernhard

    2018-01-01

    High-energy delayed γ-ray spectroscopy is a potential technique for directly assaying spent fuel assemblies and achieving the safeguards goal of quantifying nuclear material inventories for spent fuel handling, interim storage, reprocessing facilities, repository sites, and final disposal. Requirements for the γ-ray detection system, up to ∼6 MeV, can be summarized as follows: high efficiency at high γ-ray energies, high energy resolution, good linearity between γ-ray energy and output signal amplitude, ability to operate at very high count rates, and ease of use in industrial environments such as nuclear facilities. High Purity Germanium Detectors (HPGe) are the state of the art and provide excellent energy resolution but are limited in their count rate capability. Lanthanum Bromide (LaBr3) scintillation detectors offer significantly higher count rate capabilities at lower energy resolution. Thus, LaBr3 detectors may be an effective alternative for nuclear spent-fuel applications, where count-rate capability is a requirement. This paper documents the measured performance of a 2" (length) × 2" (diameter) of LaBr3 scintillation detector system, coupled to a negatively biased PMT and a tapered active high voltage divider, with count-rates up to ∼3 Mcps. An experimental methodology was developed that uses the average current from the PMT's anode and a dual source method to characterize the detector system at specific very high count rate values. Delayed γ-ray spectra were acquired with the LaBr3 detector system at the Idaho Accelerator Center, Idaho State University, where samples of ∼3g of 235U were irradiated with moderated neutrons from a photo-neutron source. Results of the spectroscopy characterization and analysis of the delayed γ-ray spectra acquired indicate the possible use of LaBr3 scintillation detectors when high count rate capability may outweigh the lower energy resolution.

  12. Gamma-ray production cross sections for 0.9 to 20 MeV neutron interactions with 10B

    International Nuclear Information System (INIS)

    Bywater, R.L. Jr.

    1986-09-01

    Gamma-ray spectral data previously obtained at the 20-meter station of the Oak Ridge Electron Linear Accelerator flight-path 8 were studied to determine cross sections for 0.9- to 20-MeV neutron interactions with 10 B. Data reduction techniques, including those for determination of incident neutron fluences as well as those to compensate for Doppler-broadened gamma-ray-detection responses, are given in some detail in this report. 9 refs., 4 figs., 2 tabs

  13. An X-ray photoelectron spectroscopy study of the products of the interaction of gaseous IrF6 with fine UO2F2

    Directory of Open Access Journals (Sweden)

    Prusakov Vladimir N.

    2007-01-01

    Full Text Available Nuclear fuel reprocessing by fluorination, a dry method of regeneration of spent nuclear fuel, uses UO2F2 for the separation of plutonium from gaseous mixtures. Since plutonium requires special treatment, IrF6 was used as a thermodynamic model of PuF6. The model reaction of the interaction of gaseous IrF6 with fine UO2F2 in the sorption column revealed a change of color of the sorption column contents from pale-yellow to gray and black, indicating the formation of products of such an interaction. The X-ray photoelectron spectroscopy study showed that the interaction of gaseous IrF6 with fine UO2F2 at 125 °C results in the formation of stable iridium compounds where the iridium oxidation state is close to Ir3+. The dependence of the elemental compositions of the layers in the sorption column on the penetration depth of IrF6 was established.

  14. On screening for Special Nuclear Materials (SNMs) with X-ray diffraction

    International Nuclear Information System (INIS)

    Harding, G.

    2010-01-01

    A novel detection technique employing X-ray diffraction (XRD) to screen for Special Nuclear Materials (SNMs), in particular for uranium, has been recently proposed. It is based on the interesting fact that uranium (and incidentally, plutonium) has a non-cubic lattice structure, in contrast to all other non-SNM, high-density elements of the Periodic Table. The principle of this screening technique is briefly elucidated by comparing the XRD lines of uranium with those of lead, a material of high atomic number (Z) commonly found in container traffic. Several physical conditions that must be satisfied to enable XRD for SNM screening are considered. To achieve adequate penetration, both of suspicious high-Z materials and their containers, photon energies of 1 MeV and above must be employed. Implications from partial coherence theory for the XRD measurement geometry at such photon energies are presented. The question of multiple scatter degradation of the coherent scatter signal is addressed. Technological considerations relevant to performing XRD at 1 MeV, particularly regarding the radiation source and detector, are discussed. A novel secondary aperture scheme permitting high energy XRD is presented. It is concluded that the importance of the application and the prospect of its feasibility are sufficient to warrant experimental verification.

  15. Monte Carlo simulation on hard X-ray dose produced in interaction between high intensity laser and solid target

    International Nuclear Information System (INIS)

    Yang Bo; Qiu Rui; Li Junli; Zhang Hui

    2014-01-01

    The X-ray dose produced in the interaction between high intensity laser and solid target was studied by simulation using Monte Carlo code. Compared with experimental results, the calculation model was verified. The calculation model was used to study the effect on X-ray dose with different electron temperatures, target materials (including Au, Cu and PE) and thicknesses. The results indicate that the X-ray dose is mainly determined by the electron temperature, and will be affected by the target parameters. X-ray dose of Au is about 1.2 times that of Cu, and is about 5 times that of PE (polyethylene). In addition, compared with other target thickness, when target thickness is the mean range of electron in the target, X-ray dose is relatively large. These results will provide references on evaluating the ionizing radiation dose for laser devices. (authors)

  16. Fermi LAT Observation of Diffuse Gamma-Rays Produced through Interactions Between Local Interstellar Matter and High Energy Cosmic Rays

    Energy Technology Data Exchange (ETDEWEB)

    Abdo, A.A.; /Naval Research Lab, Wash., D.C. /Federal City Coll.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Ajello, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U. /Stockholm U., OKC; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bloom, E.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bregeon, J.; /INFN, Pisa; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, T.H.; /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /Milan Polytechnic /Royal Inst. Tech., Stockholm /Stockholm U., OKC /DAPNIA, Saclay /INFN, Perugia /Perugia U. /NASA, Goddard /Naval Research Lab, Wash., D.C. /George Mason U. /NASA, Goddard /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Stockholm U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /ASDC, Frascati /Naval Research Lab, Wash., D.C. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /CENBG, Gradignan /CENBG, Gradignan /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Trieste /Hiroshima U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Bari U. /INFN, Bari /INFN, Bari; /more authors..

    2012-03-30

    Observations by the Large Area Telescope (LAT) on the Fermi mission of diffuse {gamma}-rays in a mid-latitude region in the third quadrant (Galactic longitude l from 200{sup o} to 260{sup o} and latitude |b| from 22{sup o} to 60{sup o}) are reported. The region contains no known large molecular cloud and most of the atomic hydrogen is within 1 kpc of the solar system. The contributions of {gamma}-ray point sources and inverse Compton scattering are estimated and subtracted. The residual {gamma}-ray intensity exhibits a linear correlation with the atomic gas column density in energy from 100 MeV to 10 GeV. The measured integrated {gamma}-ray emissivity is (1.63 {+-} 0.05) x 10{sup -26} photons s{sup -1}sr{sup -1} H-atom{sup -1} and (0.66 {+-} 0.02) x 10{sup -26} photons s{sup -1}sr{sup -1} H-atom{sup -1} above 100 MeV and above 300 MeV, respectively, with an additional systematic error of {approx}10%. The differential emissivity from 100 MeV to 10 GeV agrees with calculations based on cosmic ray spectra consistent with those directly measured, at the 10% level. The results obtained indicate that cosmic ray nuclei spectra within 1 kpc from the solar system in regions studied are close to the local interstellar spectra inferred from direct measurements at the Earth within {approx}10%.

  17. Effect of nonlinearity of spin interaction with electromagnetic resonance field on characteristics of polarized nuclear target

    International Nuclear Information System (INIS)

    Vertij, A.A.; Gavrilov, S.P.; Shestopalov, V.P.

    1990-01-01

    Interaction of incident nuclear particle beam with J = 1/2 (neutrons) spin and (J = 1/2) protons with the target substance is considered. It is shown that neutron polarization at the target exit and neutron transparency (G) of the target depend significantly on incident wave amplitude level and physical parameter values which characterize the target, such as target temperature, resonator mirror reflection factor, number of spins interacting with the field, etc. Under interaction of neutrons with a target resonator which features a high mirror reflection factor and low losses for absorption which is not related to magnetic dipole absorption, a bistable response of neutron polarization and G manifests itself. 1 ref

  18. Comparisons of experimental beta-ray spectra important to decay heat predictions with ENSDF [Evaluated Nuclear Structure Data File] evaluations

    International Nuclear Information System (INIS)

    Dickens, J.K.

    1990-03-01

    Graphical comparisons of recently obtained experimental beta-ray spectra with predicted beta-ray spectra based on the Evaluated Nuclear Structure Data File are exhibited for 77 fission products having masses 79--99 and 130--146 and lifetimes between 0.17 and 23650 sec. The comparisons range from very poor to excellent. For beta decay of 47 nuclides, estimates are made of ground-state transition intensities. For 14 cases the value in ENSDF gives results in very good agreement with the experimental data. 12 refs., 77 figs., 1 tab

  19. Average Nuclear Level Densities and Radiative Strength Functions in 56,57FE from Primary (Gamma)-Ray Spectra

    International Nuclear Information System (INIS)

    Tavukcu, E.; Becker, J.A.; Bernstein, L.A.; Garrett, P.E.; Guttormsen, M.; Mitchell, G.E.; Rekstad, J.; Schiller, A.; Siem, S.; Voinov, A.; Younes, W.

    2002-01-01

    An experimental primary γ-ray spectrum vs. excitation-energy bin (P(E x , E γ ) matrix) in a light-ion reaction is obtained for 56,57 Fe isotopes using a subtraction method. By factorizing the P(E x , E γ ) matrix according to the Axel-Brink hypothesis the nuclear level density and the radiative strength function (RSF) in 56,57 Fe are extracted simultaneously. A step structure is observed in the level density for both isotopes, and is interpreted as the breaking of Cooper pairs. The RSFs for 56,57 Fe reveal an anomalous enhancement at low γ-ray energies

  20. Influence of hadronic interaction models and the cosmic ray spectrum on the high energy atmospheric muon and neutrino flux

    OpenAIRE

    Fedynitch, Anatoli; Tjus, Julia Becker; Desiati, Paolo

    2012-01-01

    The recent observations of muon charge ratio up to about 10 TeV and of atmospheric neutrinos up to energies of about 400 TeV has triggered a renewed interest into the high-energy interaction models and cosmic ray primary composition. A reviewed calculation of lepton spectra produced in cosmic ray induced extensive air showers is carried out with a primary cosmic ray spectrum that fits the latest direct measurements below the knee. In order to achieve this, we used a full Monte Carlo method to...

  1. Note: Diagnosing femtosecond laser-solid interactions with monochromatic Kα imager and x-ray pinhole camera

    International Nuclear Information System (INIS)

    Lin, X. X.; Li, Y. T.; Liu, F.; Du, F.; Wang, S. J.; Chen, L. M.; Zhang, L.; Zheng, Y.; Liu, X.; Liu, X. L.; Wang, Z. H.; Ma, J. L.; Wei, Z. Y.; Liu, B. C.; Zhang, J.

    2011-01-01

    An x-ray pinhole camera and a monochromatic K α imager are used to measure the interactions of intense femtosecond laser pulses with Cu foil targets. The two diagnostics give different features in the spot size and the laser energy scaling, which are resulted from different physical processes. Under our experimental conditons, the K α emission is mainly excited by the fast electrons transporting inside the cold bulk target. In contrast, the x-ray pinhole signals are dominated by the broadband thermal x-ray emission from the hot plasma at the front target surface.

  2. Nuclear data relevant to single event upsets in semiconductor memories induced by cosmic-ray neutrons and protons

    International Nuclear Information System (INIS)

    Watanabe, Yukinobu

    2008-01-01

    The role of nuclear data is examined in the study of single event upset (SEU) phenomena in semiconductor memories caused by cosmic-ray neutrons and protons. Neutron and proton SEU cross sections are calculated with a simplified semi-empirical model using experimental heavy-ion SEU cross-sections and a dedicated database of neutron and proton induced reactions on 28 Si. Some impacts of the nuclear reaction data on SEU simulation are analyzed by investigating relative contribution of secondary ions and neutron elastic scattering to SEU and influence of simultaneous multiple ions emission on SEU. (author)

  3. gamma-Hadron family description by quasi-scaling model at normal nuclear composition of primary cosmic rays

    CERN Document Server

    Kalmakhelidze, M; Svanidze, M

    2002-01-01

    Primary Cosmic Rays Nuclear Composition was investigated in energy region 10 sup 1 sup 5 -10 sup 1 sup 6 eV. The study is based on comparison of gamma hadron families observed by Pamir and Pamir-Chacaltaya collaborations with those generated by means of quasi-scaling model MC0 at different nuclear compositions. It was shown that all characteristics of the observed families (including their intensity) are in very good agreement with properties of simulated events MC0 at normal composition and are in disagreement at heavy dominant compositions

  4. Tissue-specific interactions between nuclear proteins and the aminopeptidase N promoter

    DEFF Research Database (Denmark)

    Kärnström, U; Sjöström, H; Norén, O

    1991-01-01

    Aminopeptidase N/CD13 is a metallopeptidase found in many tissues. Aminopeptidase N activity is high in the small intestinal mucosa, moderate in the liver, and low in the spleen. Using DNase I footprinting and electrophoretic mobility shift assays with nuclear extracts from these tissues, three cis...... elements (DF, LF-B1, UF) were identified in the aminopeptidase N promoter. The DF region (-53 to -30) interacts with the ubiquitously expressed transcription factor Sp1. The LF-B1 region (-85 to -58) interacts with the liver transcription factor LF-B1 (HNF-1) which was detected as well in nuclei from small...... intestinal mucosa. The UF region (-112 to -90) interacts with nuclear factors which seem to be expressed differentially in the liver and the small intestine. Transfection of promoter deletions into HepG2 cells showed that the LF-B1 region is necessary for high expression of the aminopeptidase N gene in liver...

  5. Contribution of the residue at position 4 within classical nuclear localization signals to modulating interaction with importins and nuclear targeting.

    Science.gov (United States)

    Smith, Kate M; Di Antonio, Veronica; Bellucci, Luca; Thomas, David R; Caporuscio, Fabiana; Ciccarese, Francesco; Ghassabian, Hanieh; Wagstaff, Kylie M; Forwood, Jade K; Jans, David A; Palù, Giorgio; Alvisi, Gualtiero

    2018-08-01

    Nuclear import involves the recognition by importin (IMP) superfamily members of nuclear localization signals (NLSs) within protein cargoes destined for the nucleus, the best understood being recognition of classical NLSs (cNLSs) by the IMPα/β1 heterodimer. Although the cNLS consensus [K-(K/R)-X-(K/R) for positions P2-P5] is generally accepted, recent studies indicated that the contribution made by different residues at the P4 position can vary. Here, we apply a combination of microscopy, molecular dynamics, crystallography, in vitro binding, and bioinformatics approaches to show that the nature of residues at P4 indeed modulates cNLS function in the context of a prototypical Simian Virus 40 large tumor antigen-derived cNLS (KKRK, P2-5). Indeed, all hydrophobic substitutions in place of R impaired binding to IMPα and nuclear targeting, with the largest effect exerted by a G residue at P4. Substitution of R with neutral hydrophobic residues caused the loss of electrostatic and van der Waals interactions between the P4 residue side chains and IMPα. Detailed bioinformatics analysis confirmed the importance of the P4 residue for cNLS function across the human proteome, with specific residues such as G being associated with low activity. Furthermore, we validate our findings for two additional cNLSs from human cytomegalovirus (HCMV) DNA polymerase catalytic subunit UL54 and processivity factor UL44, where a G residue at P4 results in a 2-3-fold decrease in NLS activity. Our results thus showed that the P4 residue makes a hitherto poorly appreciated contribution to nuclear import efficiency, which is essential to determining the precise nuclear levels of cargoes. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Configuration interaction calculations and excitation rates of X-ray and EUV transitions in sulfurlike manganese

    Energy Technology Data Exchange (ETDEWEB)

    El-Maaref, A.A., E-mail: ahmed.maaref@azhar.edu.eg; Saddeek, Y.B.; Abou halaka, M.M.

    2017-02-15

    Highlights: • Fine-structure calculations of sulfurlike Mn have been performed using configuration interaction technique, CI. • The relativistic effects, Breit-Pauli Hameltonian, have been correlated to the CI calculations. • Excitation rates by electron impact of the Mn X ion have been evaluated up to ionization potential. - Abstract: Fine-structure calculations of energies and transition parameters have been performed using the configuration interaction technique (CI) as implemented in CIV3 code for sulfurlike manganese, Mn X. The calculations are executed in an intermediate coupling scheme using the Breit-Pauli Hamiltonian. As well as, energy levels and oscillator strengths are calculated using LANL code, where the calculations by LANL have been used to estimate the accuracy of the present CI calculations. The calculated energy levels, oscillator strengths, and lifetimes are in reasonable agreement with the published experimental and theoretical values. Electron impact excitation rates of the transitions emit soft X-ray and extreme ultraviolet (EUV) wavelengths have been evaluated. The level population densities are calculated using the collisional radiative model (CRM), as well. The collisional excitation rates and collision strengths have been calculated in the electron temperature range ≤ the ionization potential, ∼1–250 eV.

  7. FT-IR and X-ray spectroscopic investigations of Na-diclofenac-cyclodextrins interactions

    Science.gov (United States)

    Bratu, I.; Astilean, S.; Ionesc, Corina; Indrea, E.; Huvenne, J. P.; Legrand, P.

    1998-01-01

    The association of DCF-Na (the salt of the 2-[(2,6-dichlorophenyl)amino]-phenyl-acetic acid) with β-CD (cyclodextrin) in some therapeutic formulas can contribute to the optimisation of the physico-chemical and pharmaceutical properties of the parent drug. The understanding of the interaction between DCF with β-CD represents the objective of this study. FT-IR spectroscopy is one of the methods which clarify the nature of these interactions in complexes of such type. Therefore the changes in FT-IR spectra of binary dispersed systems DCF/ β-CD in physical mixture and coprecipitate from methanol (molar ratios: 1/1, 1/2, 2/3, 3/4, 7/4) were analysed. The analysis of the broadening of the X-ray powder diffraction line has been applied to investigate the average effective crystallite size, the mean square of the microstrain caused by distortions within β-CD crystallite and the fault probability in the binary dispersed DCF/ β-CD coprecipitate system.

  8. Communication: Hydrogen bonding interactions in water-alcohol mixtures from X-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Royce K.; Smith, Jacob W.; Saykally, Richard J., E-mail: saykally@berkeley.edu [Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2016-05-21

    While methanol and ethanol are macroscopically miscible with water, their mixtures exhibit negative excess entropies of mixing. Despite considerable effort in both experiment and theory, there remains significant disagreement regarding the origin of this effect. Different models for the liquid mixture structure have been proposed to address this behavior, including the enhancement of the water hydrogen bonding network around the alcohol hydrophobic groups and microscopic immiscibility or clustering. We have investigated mixtures of methanol, ethanol, and isopropanol with water by liquid microjet X-ray absorption spectroscopy on the oxygen K-edge, an atom-specific probe providing details of both inter- and intra-molecular structure. The measured spectra evidence a significant enhancement of hydrogen bonding originating from the methanol and ethanol hydroxyl groups upon the addition of water. These additional hydrogen bonding interactions would strengthen the liquid-liquid interactions, resulting in additional ordering in the liquid structures and leading to a reduction in entropy and a negative enthalpy of mixing, consistent with existing thermodynamic data. In contrast, the spectra of the isopropanol-water mixtures exhibit an increase in the number of broken alcohol hydrogen bonds for mixtures containing up to 0.5 water mole fraction, an observation consistent with existing enthalpy of mixing data, suggesting that the measured negative excess entropy is a result of clustering or micro-immiscibility.

  9. Communication: Hydrogen bonding interactions in water-alcohol mixtures from X-ray absorption spectroscopy

    Science.gov (United States)

    Lam, Royce K.; Smith, Jacob W.; Saykally, Richard J.

    2016-05-01

    While methanol and ethanol are macroscopically miscible with water, their mixtures exhibit negative excess entropies of mixing. Despite considerable effort in both experiment and theory, there remains significant disagreement regarding the origin of this effect. Different models for the liquid mixture structure have been proposed to address this behavior, including the enhancement of the water hydrogen bonding network around the alcohol hydrophobic groups and microscopic immiscibility or clustering. We have investigated mixtures of methanol, ethanol, and isopropanol with water by liquid microjet X-ray absorption spectroscopy on the oxygen K-edge, an atom-specific probe providing details of both inter- and intra-molecular structure. The measured spectra evidence a significant enhancement of hydrogen bonding originating from the methanol and ethanol hydroxyl groups upon the addition of water. These additional hydrogen bonding interactions would strengthen the liquid-liquid interactions, resulting in additional ordering in the liquid structures and leading to a reduction in entropy and a negative enthalpy of mixing, consistent with existing thermodynamic data. In contrast, the spectra of the isopropanol-water mixtures exhibit an increase in the number of broken alcohol hydrogen bonds for mixtures containing up to 0.5 water mole fraction, an observation consistent with existing enthalpy of mixing data, suggesting that the measured negative excess entropy is a result of clustering or micro-immiscibility.

  10. Interactive real-time nuclear plant simulations on a UNIX based supercomputer

    International Nuclear Information System (INIS)

    Behling, S.R.

    1990-01-01

    Interactive real-time nuclear plant simulations are critically important to train nuclear power plant engineers and operators. In addition, real-time simulations can be used to test the validity and timing of plant technical specifications and operational procedures. To accurately and confidently simulate a nuclear power plant transient in real-time, sufficient computer resources must be available. Since some important transients cannot be simulated using preprogrammed responses or non-physical models, commonly used simulation techniques may not be adequate. However, the power of a supercomputer allows one to accurately calculate the behavior of nuclear power plants even during very complex transients. Many of these transients can be calculated in real-time or quicker on the fastest supercomputers. The concept of running interactive real-time nuclear power plant transients on a supercomputer has been tested. This paper describes the architecture of the simulation program, the techniques used to establish real-time synchronization, and other issues related to the use of supercomputers in a new and potentially very important area. (author)

  11. X-ray spectroscopy of highly ionized heavy ions as an advanced research for controlled nuclear fusion power

    International Nuclear Information System (INIS)

    Zschornack, G.; Musiol, G.

    1988-01-01

    Diagnostics and modelling of nuclear fusion plasmas require a detailed knowledge of atomic and molecular data for highly ionized heavy ions. Experimental verification of atomic data is made on the basis of IAEA recommendations using the method of high-resolution wavelength-dispersive X-ray spectroscopy in order to obtain contributions extensioning the available atomic data lists. Basic facilities for producing highly charged heavy ions are the electron-ion rings of the heavy ion collective accelerator and the electron beam ion source KRYON-2 at the Joint Institute for Nuclear Research at Dubna. For high-resolution X-ray spectroscopy with these sources a computer-aided crystal diffraction spectrometer has been developed the precision of which is achieved by using advanced principles of measurement and control. Relativistic atomic structure calculations have been carried out for a great number of elements and configurations to obtain data in ionization regions heavily accessible to the experiment. (author)

  12. X-ray optical diagnostic of laser produced plasmas for nuclear fusion and X-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Butzbach, R.

    2001-07-01

    In the present work, the conception, design and appliance of toroidally bent crystals for the X-ray optical diagnostics of laser produced plasmas is discussed. The first part of this work deals with the development, design and characterization of an X-Ray microscope for the observation of Rayleigh-Taylor instabilities, which act against the confinement and ignition of the fuel in the inertial confinement fusion process. The aim of the second part of the present work was the diagnostic of the lasing medium for amplified spontaneous emission close to the water window. For this purpose, an one-dimensionally (1-D) imaging X-ray spectrometer based on toroidally bent quartz crystals was developed for the observation of the Ni-like 4f-3d transition of Yb, Hf, Ta, and W ions, which should be related to the amplified 4d-4p emission, since the 4f niveau is very close to the 4d niveau. Thus, the 4f-3d transition can serve as an indicator for the population of the 4d niveau. (orig.)

  13. Nuclear level densities and γ-ray strength functions of 180,181Ta and neutron capture cross sections

    Science.gov (United States)

    Malatji, K. L.; Kheswa, B. V.; Wiedeking, M.; Bello Garrote, F. L.; Brits, C. P.; Bleuel, D. L.; Giacoppo, F.; Görgen, A.; Guttormsen, M.; Hadynska-Klek, K.; Hagen, T. W.; Ingeberg, V. W.; Klintefjord, M.; Larsen, A. C.; Nyhus, H. T.; Renstrøm, T.; Rose, S.; Sahin, E.; Siem, S.; Tveten, G. M.; Zeiser, F.

    2017-09-01

    The γ-ray strength functions and nuclear level densities in the quasi-continuum of 180,181Ta are extracted from particle-γ coincidence events with the Oslo Method, below the Sn. The data were used as input in the TALYS reaction code for calculations of the astrophysical Maxwellian-averaged (n,γ) cross-sections to investigate nucleosynthesis of nature's rarest stable isotope 180Ta.

  14. Nuclear level densities and γ-ray strength functions of 180,181Ta and neutron capture cross sections

    Directory of Open Access Journals (Sweden)

    Malatji K.L.

    2017-01-01

    Full Text Available The γ-ray strength functions and nuclear level densities in the quasi-continuum of 180,181Ta are extracted from particle-γ coincidence events with the Oslo Method, below the Sn. The data were used as input in the TALYS reaction code for calculations of the astrophysical Maxwellian-averaged (n,γ cross-sections to investigate nucleosynthesis of nature's rarest stable isotope 180Ta.

  15. The CCR4-NOT complex physically and functionally interacts with TRAMP and the nuclear exosome.

    Directory of Open Access Journals (Sweden)

    Nowel Azzouz

    Full Text Available BACKGROUND: Ccr4-Not is a highly conserved multi-protein complex consisting in yeast of 9 subunits, including Not5 and the major yeast deadenylase Ccr4. It has been connected functionally in the nucleus to transcription by RNA polymerase II and in the cytoplasm to mRNA degradation. However, there has been no evidence so far that this complex is important for RNA degradation in the nucleus. METHODOLOGY/PRINCIPAL FINDINGS: In this work we point to a new role for the Ccr4-Not complex in nuclear RNA metabolism. We determine the importance of the Ccr4-Not complex for the levels of non-coding nuclear RNAs, such as mis-processed and polyadenylated snoRNAs, whose turnover depends upon the nuclear exosome and TRAMP. Consistently, mutation of both the Ccr4-Not complex and the nuclear exosome results in synthetic slow growth phenotypes. We demonstrate physical interactions between the Ccr4-Not complex and the exosome. First, Not5 co-purifies with the exosome. Second, several exosome subunits co-purify with the Ccr4-Not complex. Third, the Ccr4-Not complex is important for the integrity of large exosome-containing complexes. Finally, we reveal a connection between the Ccr4-Not complex and TRAMP through the association of the Mtr4 helicase with the Ccr4-Not complex and the importance of specific subunits of Ccr4-Not for the association of Mtr4 with the nuclear exosome subunit Rrp6. CONCLUSIONS/SIGNIFICANCE: We propose a model in which the Ccr4-Not complex may provide a platform contributing to dynamic interactions between the nuclear exosome and its co-factor TRAMP. Our findings connect for the first time the different players involved in nuclear and cytoplasmic RNA degradation.

  16. A redefinition of the energy ansata, leading to a fundamentally new class of nuclear interactions

    International Nuclear Information System (INIS)

    Bearden, T.E.

    1992-01-01

    Utilizing fundamental new definitions for energy, potential, and scalar potential, the mass of the atomic nucleus may be considered a powerful electrostatic scalar potential, referred to as the mass potential. The Whittaker EM biwave structure of the scalar potential then becomes a new and universal internal EM structure for mass, including the atomic nucleus. This structure can be directly manipulated electromagnetically, which allows direct EM alteration of the mass potential , and the nucleus itself. This totally new class of nuclear interactions is briefly explored in this paper, and several hypothesized mechanisms advanced for neutralizing or processing nuclear wastes. Additional applications are hypothesized for experimental falsification or verification

  17. Validation of seismic soil structure interaction (SSI) methodology for a UK PWR nuclear power station

    International Nuclear Information System (INIS)

    Llambias, J.M.

    1993-01-01

    The seismic loading information for use in the seismic design of equipment and minor structures within a nuclear power plant is determined from a dynamic response analysis of the building in which they are located. This dynamic response analysis needs to capture the global response of both the building structure and adjacent soil and is commonly referred to as a soil structure interaction (SSI) analysis. NNC have developed a simple and cost effective methodology for the seismic SSI analysis of buildings in a PWR nuclear power station at a UK soft site. This paper outlines the NNC methodology and describes the approach adopted for its validation

  18. Investigation of the proton-neutron interaction by high-precision nuclear mass measurements

    CERN Multimedia

    Savreux, R P; Akkus, B

    2007-01-01

    We propose to measure the atomic masses of a series of short-lived nuclides, including $^{70}$Ni, $^{122-130}$Cd, $^{134}$Sn, $^{138,140}$Xe, $^{207-210}$Hg, and $^{223-225}$Rn, that contribute to the investigation of the proton-neutron interaction and its role in nuclear structure. The high-precision mass measurements are planned for the Penning trap mass spectrometer ISOLTRAP that reaches the required precision of 10 keV in the nuclear mass determination.

  19. Nuclear Malaysia Plasma Focus Device as a X-ray Source For Radiography Applications

    International Nuclear Information System (INIS)

    Rokiah Mohd Sabri; Abdul Halim Baijan; Siti Aiasah Hashim; Mohd Rizal Mohd Chulan; Wah, L.K.; Mukhlis Mokhtar; Azaman Ahmad; Rosli Che Ros

    2013-01-01

    A 3.375 kJ plasma focus is designed to operate at 13.5 kV for the purpose of studying x-ray source for radiography in Argon discharge. X-rays is detected by using x-ray film from the mammography radiographic plate. The feasibility of the plasma focus as a high intensity flash x-ray source for good contrast in radiography image is presented. (author)

  20. Genome-Nuclear Lamina Interactions Regulate Cardiac Stem Cell Lineage Restriction.

    Science.gov (United States)

    Poleshko, Andrey; Shah, Parisha P; Gupta, Mudit; Babu, Apoorva; Morley, Michael P; Manderfield, Lauren J; Ifkovits, Jamie L; Calderon, Damelys; Aghajanian, Haig; Sierra-Pagán, Javier E; Sun, Zheng; Wang, Qiaohong; Li, Li; Dubois, Nicole C; Morrisey, Edward E; Lazar, Mitchell A; Smith, Cheryl L; Epstein, Jonathan A; Jain, Rajan

    2017-10-19

    Progenitor cells differentiate into specialized cell types through coordinated expression of lineage-specific genes and modification of complex chromatin configurations. We demonstrate that a histone deacetylase (Hdac3) organizes heterochromatin at the nuclear lamina during cardiac progenitor lineage restriction. Specification of cardiomyocytes is associated with reorganization of peripheral heterochromatin, and independent of deacetylase activity, Hdac3 tethers peripheral heterochromatin containing lineage-relevant genes to the nuclear lamina. Deletion of Hdac3 in cardiac progenitor cells releases genomic regions from the nuclear periphery, leading to precocious cardiac gene expression and differentiation into cardiomyocytes; in contrast, restricting Hdac3 to the nuclear periphery rescues myogenesis in progenitors otherwise lacking Hdac3. Our results suggest that availability of genomic regions for activation by lineage-specific factors is regulated in part through dynamic chromatin-nuclear lamina interactions and that competence of a progenitor cell to respond to differentiation signals may depend upon coordinated movement of responding gene loci away from the nuclear periphery. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Additional mitochondrial DNA influences the interactions between the nuclear and mitochondrial genomes in a bovine embryo model of nuclear transfer.

    Science.gov (United States)

    Srirattana, Kanokwan; St John, Justin C

    2018-05-08

    We generated cattle embryos using mitochondrial supplementation and somatic cell nuclear transfer (SCNT), named miNT, to determine how additional mitochondrial DNA (mtDNA) modulates the nuclear genome. To eliminate any confounding effects from somatic cell mtDNA in intraspecies SCNT, donor cell mtDNA was depleted prior to embryo production. Additional oocyte mtDNA did not affect embryo development rates but increased mtDNA copy number in blastocyst stage embryos. Moreover, miNT-derived blastocysts had different gene expression profiles when compared with SCNT-derived blastocysts. Additional mtDNA increased expression levels of genes involved in oxidative phosphorylation, cell cycle and DNA repair. Supplementing the embryo culture media with a histone deacetylase inhibitor, Trichostatin A (TSA), had no beneficial effects on the development of miNT-derived embryos, unlike SCNT-derived embryos. When compared with SCNT-derived blastocysts cultured in the presence of TSA, additional mtDNA alone had beneficial effects as the activity of glycolysis may increase and embryonic cell death may decrease. However, these beneficial effects were not found with additional mtDNA and TSA together, suggesting that additional mtDNA alone enhances reprogramming. In conclusion, additional mtDNA increased mtDNA copy number and expression levels of genes involved in energy production and embryo development in blastocyst stage embryos emphasising the importance of nuclear-mitochondrial interactions.

  2. Nuclear scaffold organization in the X-ray sensitive Chinese hamster mutant cell line, xrs-5

    International Nuclear Information System (INIS)

    Yasui, L.S.; Fink, T.J.; Enrique, A.M.

    1994-01-01

    Nuclear organization was probed in the radiation-sensitive Chinese hamster ovary (CHO) cell line, xrs-5, and compared with parental CHO K1 cells using the resinless section technique and DNase I digestions. The resinless section data showed no gross morphological differences in core filaments from the nuclear scaffolds of unirradiated CHO K1 and xrs-5 cells. However, the nuclear scaffolds of irradiated xrs-5 cells (1 Gy) had significantly increased ground substance. Irradiated and unirradiated CHO K1 cell nuclear scaffolds were morphologically identical. These data suggest that both CHO K1 and xrs-5 cell nuclear scaffolds had internal nuclear scaffolding networks that could provide DNA attachment sites. (author)

  3. High-resolution multi-MeV x-ray radiography using relativistic laser-solid interaction

    International Nuclear Information System (INIS)

    Courtois, C.; Compant La Fontaine, A.; Barbotin, M.; Bazzoli, S.; Brebion, D.; Bourgade, J. L.; Gazave, J.; Lagrange, J. M.; Landoas, O.; Le Dain, L.; Lefebvre, E.; Pichoff, N.; Edwards, R.; Aedy, C.; Biddle, L.; Drew, D.; Gardner, M.; Ramsay, M.; Simons, A.; Sircombe, N.

    2011-01-01

    When high intensity (≥10 19 W cm -2 ) laser light interacts with matter, multi-MeV electrons are produced. These electrons can be utilized to generate a MeV bremsstrahlung x-ray emission spectrum as they propagate into a high-Z solid target positioned behind the interaction area. The short duration ( 2 ) object is then performed with few hundred microns spatial resolution.

  4. Nondestructive Inspection System for Special Nuclear Material Using Inertial Electrostatic Confinement Fusion Neutrons and Laser Compton Scattering Gamma-Rays

    Science.gov (United States)

    Ohgaki, H.; Daito, I.; Zen, H.; Kii, T.; Masuda, K.; Misawa, T.; Hajima, R.; Hayakawa, T.; Shizuma, T.; Kando, M.; Fujimoto, S.

    2017-07-01

    A Neutron/Gamma-ray combined inspection system for hidden special nuclear materials (SNMs) in cargo containers has been developed under a program of Japan Science and Technology Agency in Japan. This inspection system consists of an active neutron-detection system for fast screening and a laser Compton backscattering gamma-ray source in coupling with nuclear resonance fluorescence (NRF) method for precise inspection. The inertial electrostatic confinement fusion device has been adopted as a neutron source and two neutron-detection methods, delayed neutron noise analysis method and high-energy neutron-detection method, have been developed to realize the fast screening system. The prototype system has been constructed and tested in the Reactor Research Institute, Kyoto University. For the generation of the laser Compton backscattering gamma-ray beam, a race track microtron accelerator has been used to reduce the size of the system. For the NRF measurement, an array of LaBr3(Ce) scintillation detectors has been adopted to realize a low-cost detection system. The prototype of the gamma-ray system has been demonstrated in the Kansai Photon Science Institute, National Institutes for Quantum and Radiological Science and Technology. By using numerical simulations based on the data taken from these prototype systems and the inspection-flow, the system designed by this program can detect 1 kg of highly enriched 235U (HEU) hidden in an empty 20-ft container within several minutes.

  5. New parameterizations of the Gogny effective nuclear interaction; Nouvelles parametrisations de l'interaction nucleaire effective de Gogny

    Energy Technology Data Exchange (ETDEWEB)

    Chappert, F

    2007-06-15

    The effective interaction between nucleons is the basic input to microscopic calculations in nuclear structure. One of the forms used since the 1970's is the phenomenological effective force proposed by D. Gogny. This force gives excellent results in nuclei at the mean-field approximation. The presence of contact terms does not allow, however, to use it for the description of beyond mean-field correlations present in nuclei. In this work, we investigate some extensions of the Gogny force, and especially a generalization in which the zero range density dependent term has been replaced by a finite range term. The parameters occurring in the analytical form of the force have been adjusted on symmetric infinite nuclear matter and neutron matter properties, and on some selected observables for stable nuclei, especially those related to pairing correlations. We present the method to include this kind of force in Hartree-Fock-Bogoliubov calculations and we analyze the results obtained for various nuclei. The new versions of the Gogny force allow us to reproduce nuclear structure properties with improved accuracy as compared to the former version. (author)

  6. A dated molecular phylogeny of manta and devil rays (Mobulidae) based on mitogenome and nuclear sequences.

    Science.gov (United States)

    Poortvliet, Marloes; Olsen, Jeanine L; Croll, Donald A; Bernardi, Giacomo; Newton, Kelly; Kollias, Spyros; O'Sullivan, John; Fernando, Daniel; Stevens, Guy; Galván Magaña, Felipe; Seret, Bernard; Wintner, Sabine; Hoarau, Galice

    2015-02-01

    Manta and devil rays are an iconic group of globally distributed pelagic filter feeders, yet their evolutionary history remains enigmatic. We employed next generation sequencing of mitogenomes for nine of the 11 recognized species and two outgroups; as well as additional Sanger sequencing of two mitochondrial and two nuclear genes in an extended taxon sampling set. Analysis of the mitogenome coding regions in a Maximum Likelihood and Bayesian framework provided a well-resolved phylogeny. The deepest divergences distinguished three clades with high support, one containing Manta birostris, Manta alfredi, Mobula tarapacana, Mobula japanica and Mobula mobular; one containing Mobula kuhlii, Mobula eregoodootenkee and Mobula thurstoni; and one containing Mobula munkiana, Mobula hypostoma and Mobula rochebrunei. Mobula remains paraphyletic with the inclusion of Manta, a result that is in agreement with previous studies based on molecular and morphological data. A fossil-calibrated Bayesian random local clock analysis suggests that mobulids diverged from Rhinoptera around 30 Mya. Subsequent divergences are characterized by long internodes followed by short bursts of speciation extending from an initial episode of divergence in the Early and Middle Miocene (19-17 Mya) to a second episode during the Pliocene and Pleistocene (3.6 Mya - recent). Estimates of divergence dates overlap significantly with periods of global warming, during which upwelling intensity - and related high primary productivity in upwelling regions - decreased markedly. These periods are hypothesized to have led to fragmentation and isolation of feeding regions leading to possible regional extinctions, as well as the promotion of allopatric speciation. The closely shared evolutionary history of mobulids in combination with ongoing threats from fisheries and climate change effects on upwelling and food supply, reinforces the case for greater protection of this charismatic family of pelagic filter feeders

  7. Plastid-Nuclear Interaction and Accelerated Coevolution in Plastid Ribosomal Genes in Geraniaceae.

    Science.gov (United States)

    Weng, Mao-Lun; Ruhlman, Tracey A; Jansen, Robert K

    2016-06-27

    Plastids and mitochondria have many protein complexes that include subunits encoded by organelle and nuclear genomes. In animal cells, compensatory evolution between mitochondrial and nuclear-encoded subunits was identified and the high mitochondrial mutation rates were hypothesized to drive compensatory evolution in nuclear genomes. In plant cells, compensatory evolution between plastid and nucleus has rarely been investigated in a phylogenetic framework. To investigate plastid-nuclear coevolution, we focused on plastid ribosomal protein genes that are encoded by plastid and nuclear genomes from 27 Geraniales species. Substitution rates were compared for five sets of genes representing plastid- and nuclear-encoded ribosomal subunit proteins targeted to the cytosol or the plastid as well as nonribosomal protein controls. We found that nonsynonymous substitution rates (dN) and the ratios of nonsynonymous to synonymous substitution rates (ω) were accelerated in both plastid- (CpRP) and nuclear-encoded subunits (NuCpRP) of the plastid ribosome relative to control sequences. Our analyses revealed strong signals of cytonuclear coevolution between plastid- and nuclear-encoded subunits, in which nonsynonymous substitutions in CpRP and NuCpRP tend to occur along the same branches in the Geraniaceae phylogeny. This coevolution pattern cannot be explained by physical interaction between amino acid residues. The forces driving accelerated coevolution varied with cellular compartment of the sequence. Increased ω in CpRP was mainly due to intensified positive selection whereas increased ω in NuCpRP was caused by relaxed purifying selection. In addition, the many indels identified in plastid rRNA genes in Geraniaceae may have contributed to changes in plastid subunits. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  8. Plastid–Nuclear Interaction and Accelerated Coevolution in Plastid Ribosomal Genes in Geraniaceae

    Science.gov (United States)

    Weng, Mao-Lun; Ruhlman, Tracey A.; Jansen, Robert K.

    2016-01-01

    Plastids and mitochondria have many protein complexes that include subunits encoded by organelle and nuclear genomes. In animal cells, compensatory evolution between mitochondrial and nuclear-encoded subunits was identified and the high mitochondrial mutation rates were hypothesized to drive compensatory evolution in nuclear genomes. In plant cells, compensatory evolution between plastid and nucleus has rarely been investigated in a phylogenetic framework. To investigate plastid–nuclear coevolution, we focused on plastid ribosomal protein genes that are encoded by plastid and nuclear genomes from 27 Geraniales species. Substitution rates were compared for five sets of genes representing plastid- and nuclear-encoded ribosomal subunit proteins targeted to the cytosol or the plastid as well as nonribosomal protein controls. We found that nonsynonymous substitution rates (dN) and the ratios of nonsynonymous to synonymous substitution rates (ω) were accelerated in both plastid- (CpRP) and nuclear-encoded subunits (NuCpRP) of the plastid ribosome relative to control sequences. Our analyses revealed strong signals of cytonuclear coevolution between plastid- and nuclear-encoded subunits, in which nonsynonymous substitutions in CpRP and NuCpRP tend to occur along the same branches in the Geraniaceae phylogeny. This coevolution pattern cannot be explained by physical interaction between amino acid residues. The forces driving accelerated coevolution varied with cellular compartment of the sequence. Increased ω in CpRP was mainly due to intensified positive selection whereas increased ω in NuCpRP was caused by relaxed purifying selection. In addition, the many indels identified in plastid rRNA genes in Geraniaceae may have contributed to changes in plastid subunits. PMID:27190001

  9. Mitochondrial-nuclear genome interactions in non-alcoholic fatty liver disease in mice.

    Science.gov (United States)

    Betancourt, Angela M; King, Adrienne L; Fetterman, Jessica L; Millender-Swain, Telisha; Finley, Rachel D; Oliva, Claudia R; Crowe, David R; Ballinger, Scott W; Bailey, Shannon M

    2014-07-15

    NAFLD (non-alcoholic fatty liver disease) involves significant changes in liver metabolism characterized by oxidative stress, lipid accumulation and fibrogenesis. Mitochondrial dysfunction and bioenergetic defects also contribute to NAFLD. In the present study, we examined whether differences in mtDNA influence NAFLD. To determine the role of mitochondrial and nuclear genomes in NAFLD, MNX (mitochondrial-nuclear exchange) mice were fed an atherogenic diet. MNX mice have mtDNA from C57BL/6J mice on a C3H/HeN nuclear background and vice versa. Results from MNX mice were compared with wild-type C57BL/6J and C3H/HeN mice fed a control or atherogenic diet. Mice with the C57BL/6J nuclear genome developed more macrosteatosis, inflammation and fibrosis compared with mice containing the C3H/HeN nuclear genome when fed the atherogenic diet. These changes were associated with parallel alterations in inflammation and fibrosis gene expression in wild-type mice, with intermediate responses in MNX mice. Mice with the C57BL/6J nuclear genome had increased State 4 respiration, whereas MNX mice had decreased State 3 respiration and RCR (respiratory control ratio) when fed the atherogenic diet. Complex IV activity and most mitochondrial biogenesis genes were increased in mice with the C57BL/6J nuclear or mitochondrial genome, or both fed the atherogenic diet. These results reveal new interactions between mitochondrial and nuclear genomes and support the concept that mtDNA influences mitochondrial function and metabolic pathways implicated in NAFLD.

  10. Mitochondrial-nuclear genome interactions in nonalcoholic fatty liver disease in mice

    Science.gov (United States)

    Betancourt, Angela M.; King, Adrienne L.; Fetterman, Jessica L.; Millender-Swain, Telisha; Finley, Rachel D.; Oliva, Claudia R.; Crowe, David Ralph; Ballinger, Scott W.; Bailey, Shannon M.

    2014-01-01

    Nonalcoholic fatty liver disease (NAFLD) involves significant changes in liver metabolism characterized by oxidative stress, lipid accumulation, and fibrogenesis. Mitochondrial dysfunction and bioenergetic defects also contribute to NAFLD. Herein, we examined whether differences in mtDNA influence NAFLD. To determine the role of mitochondrial and nuclear genomes in NAFLD, Mitochondrial-Nuclear eXchange (MNX) mice were fed an atherogenic diet. MNX mice have mtDNA from C57BL/6J mice on a C3H/HeN nuclear background and vice versa. Results from MNX mice were compared to wild-type C57BL/6J and C3H/HeN mice fed a control or atherogenic diet. Mice with the C57BL/6J nuclear genome developed more macrosteatosis, inflammation, and fibrosis compared with mice containing the C3H/HeN nuclear genome when fed the atherogenic diet. These changes were associated with parallel alterations in inflammation and fibrosis gene expression in wild-type mice, with intermediate responses in MNX mice. Mice with the C57BL/6J nuclear genome had increased State 4 respiration, whereas MNX mice had decreased State 3 respiration and RCR when fed the atherogenic diet. Complex IV activity and most mitochondrial biogenesis genes were increased in mice with the C57BL/6J nuclear or mitochondrial genome, or both fed the atherogenic diet. These results reveal new interactions between mitochondrial and nuclear genomes and support the concept that mtDNA influences mitochondrial function and metabolic pathways implicated in NAFLD. PMID:24758559

  11. Verification of Spent Nuclear Fuel in Sealed Dry Storage Casks via Measurements of Cosmic-Ray Muon Scattering

    Science.gov (United States)

    Durham, J. M.; Poulson, D.; Bacon, J.; Chichester, D. L.; Guardincerri, E.; Morris, C. L.; Plaud-Ramos, K.; Schwendiman, W.; Tolman, J. D.; Winston, P.

    2018-04-01

    Most of the plutonium in the world resides inside spent nuclear reactor fuel rods. This high-level radioactive waste is commonly held in long-term storage within large, heavily shielded casks. Currently, international nuclear safeguards inspectors have no stand-alone method of verifying the amount of reactor fuel stored within a sealed cask. Here we demonstrate experimentally that measurements of the scattering angles of cosmic-ray muons, which pass through a storage cask, can be used to determine if spent fuel assemblies are missing without opening the cask. This application of technology and methods commonly used in high-energy particle physics provides a potential solution to this long-standing problem in international nuclear safeguards.

  12. Determining of the nuclear composition of primary cosmic rays from the experimental distributions of multiple muons in atmospheric showers

    International Nuclear Information System (INIS)

    Beshtoev, Kh.M.

    1993-01-01

    Various approaches are discussed for determining the nuclear composition of the primary cosmic radiation from the distributions of multiple muons. Results are presented of calculations of the distributions of multiple muons for A 1 , A 4 , A 14 , A 26 , A 56 nuclei for an infinite plane and for the underground scintillation telescope of the Institute for Nuclear Research of the Academy of Sciences of Russia.The most suitable technique for determination of the primary nuclear composition of cosmic rays from the distribution of multiple muons is shown to be the approximate solution of a set of N equations, in which the respective coefficients of the contributions of various nuclei A i (i=1-N) to the primary composition serve as variables, while the remaining parts of these equations are the distributions of multiple muons obtained experimentally. 7 refs.; 2 tabs

  13. Standard test method for nondestructive assay of special nuclear material holdup using Gamma-Ray spectroscopic methods

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This test method describes gamma-ray methods used to nondestructively measure the quantity of 235U, or 239Pu remaining as holdup in nuclear facilities. Holdup occurs in all facilities where nuclear material is processed, in process equipment, in exhaust ventilation systems and in building walls and floors. 1.2 This test method includes information useful for management, planning, selection of equipment, consideration of interferences, measurement program definition, and the utilization of resources (1, 2, 3, 4). 1.3 The measurement of nuclear material hold up in process equipment requires a scientific knowledge of radiation sources and detectors, transmission of radiation, calibration, facility operations and error analysis. It is subject to the constraints of the facility, management, budget, and schedule; plus health and safety requirements; as well as the laws of physics. The measurement process includes defining measurement uncertainties and is sensitive to the form and distribution of the material...

  14. FENDL/E. Evaluated nuclear data library of neutron nuclear interaction cross-sections and photon production cross-sections and photon-atom interaction cross sections for fusion applications. Version 1.1 of November 1994

    International Nuclear Information System (INIS)

    Pashchenko, A.B.; Wienke, H.; Ganesan, S.; McLaughlin, P.K.

    1996-01-01

    This document presents the description of a physical tape containing the basic evaluated nuclear data library of neutron nuclear interaction cross-sections and photon production cross-sections and photon-atom interaction cross-sections for fusion applications. It is part of FENDL, the evaluated nuclear data library for fusion applications. The nuclear data are available cost-free for distribution to interested scientists upon request. The data can also be retrieved by the user via online access through international computer networks. (author). 11 refs, 1 tab

  15. The nuclear equation of state: A tool to constrain in-medium hadronic interactions

    International Nuclear Information System (INIS)

    Sammarruca, F.; Krastev, P. G.

    2006-01-01

    Recently we have been concerned with the properties of the nuclear equation of state (EOS), a relation between thermodynamic variables characterizing a medium. At zero temperature, such relation can be expressed in terms of energy (or pressure) as a function of density. Mechanisms such as isospin and/or spin asymmetry can have a dramatic impact on the equation of state. After briefly reviewing our previous work concerning the isospin asymmetries of the EOS, we will concentrate on our most recent results and their relevance towards a better understanding of the nuclear force in exotic matter. The approach we take is microscopic and relativistic. The calculated EOS properties are derived self-consistently from realistic nucleon-nucleon interactions. This makes it possible to understand the predictions in terms of specific features of the nuclear force model.

  16. Antiferromagnetic spin phase transition in nuclear matter with effective Gogny interaction

    International Nuclear Information System (INIS)

    Isayev, A.A.; Yang, J.

    2004-01-01

    The possibility of ferromagnetic and antiferromagnetic phase transitions in symmetric nuclear matter is analyzed within the framework of a Fermi liquid theory with the effective Gogny interaction. It is shown that at some critical density nuclear matter with the D1S effective force undergoes a phase transition to the antiferromagnetic spin state (opposite directions of neutron and proton spins). The self-consistent equations of spin polarized nuclear matter with the D1S force have no solutions corresponding to ferromagnetic spin ordering (the same direction of neutron and proton spins) and, hence, the ferromagnetic transition does not appear. The dependence of the antiferromagnetic spin polarization parameter as a function of density is found at zero temperature

  17. Time-domain soil-structure interaction analysis of nuclear facilities

    International Nuclear Information System (INIS)

    Coleman, Justin L.; Bolisetti, Chandrakanth; Whittaker, Andrew S.

    2016-01-01

    The Nuclear Regulatory Commission (NRC) regulation 10 CFR Part 50 Appendix S requires consideration of soil-structure interaction (SSI) in nuclear power plant (NPP) analysis and design. Soil-structure interaction analysis for NPPs is routinely carried out using guidance provided in the ASCE Standard 4-98 titled “Seismic Analysis of Safety-Related Nuclear Structures and Commentary”. This Standard, which is currently under revision, provides guidance on linear seismic soil-structure-interaction (SSI) analysis of nuclear facilities using deterministic and probabilistic methods. A new appendix has been added to the forthcoming edition of ASCE Standard 4 to provide guidance for time-domain, nonlinear SSI (NLSSI) analysis. Nonlinear SSI analysis will be needed to simulate material nonlinearity in soil and/or structure, static and dynamic soil pressure effects on deeply embedded structures, local soil failure at the foundation-soil interface, nonlinear coupling of soil and pore fluid, uplift or sliding of the foundation, nonlinear effects of gaps between the surrounding soil and the embedded structure and seismic isolation systems, none of which can be addressed explicitly at present. Appendix B of ASCE Standard 4 provides general guidance for NLSSI analysis but will not provide a methodology for performing the analysis. This paper provides a description of an NLSSI methodology developed for application to nuclear facilities, including NPPs. This methodology is described as series of sequential steps to produce reasonable results using any time-domain numerical code. These steps require some numerical capabilities, such as nonlinear soil constitutive models, which are also described in the paper.

  18. Institutional interactions in developing a transportation system under the Nuclear Waste Policy Act

    International Nuclear Information System (INIS)

    Denny, S.H.

    1986-01-01

    The Department of Energy (DOE) recognizes that the success of its efforts to develop and operate a system for transporting nuclear waste under the provisions of the Nuclear Waste Policy Act of 1982 (NWPA) depends in large measure on the effectiveness of Departmental interactions with the affected parties. To ensure the necessary network of communication, the DOE is establishing lines of contact with those who are potential participants in the task of developing the policies and procedures for the NWPA transportation system. In addition, a number of measures have been initiated to reinforce broad-based involvement in program development. The Transportation Institutional Plan provides a preliminary road map of DOE's projected interactions over the next decade and is discussed in this paper

  19. Azimuthal angle dependence of Coulomb and nuclear interactions between two deformed nuclei

    International Nuclear Information System (INIS)

    Ismail, M.; Ellithi, A. Y.; Botros, M. M.; Mellik, A. E.

    2007-01-01

    The azimuthal angle (φ) variation of the Coulomb and nuclear heavy ion (HI) potentials is studied in the framework of the double folding model, which is derived from realistic nuclear density distributions and a nucleon-nucleon (NN) interaction. The present calculation shows that the variation of HI potentials with the azimuthal angle depends strongly on the range of the NN forces. For the long-range Coulomb force, the maximum variation with φ is about 0.9%, and for HI potential derived from zero-range NN interaction the φ-variation can reach up to 90.0%. Our calculations are compared with the recent φ-dependence of the HI potential derived from proximity method. The present realistic φ-dependence calculations of the HI potential is completely different from the results of the proximity calculations

  20. A full-configuration-interaction nuclear orbital approach and application for small doped He clusters

    Energy Technology Data Exchange (ETDEWEB)

    Lara-Castells, M. P. de, E-mail: delara@iff.csic.es; Aguirre, N. F., E-mail: delara@iff.csic.es; Delgado-Barrio, G., E-mail: delara@iff.csic.es; Villarreal, P., E-mail: delara@iff.csic.es [Instituto de Física Fundamental (CSIC), Serrano 123, 28006 Madrid (Spain); Mitrushchenkov, A. O. [Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 bd Descartes, 77454 Marne-la-Vallée (France)

    2015-01-22

    An efficient full-configuration-interaction 'nuclear orbital' treatment was developed as a benchmark quantum-chemistry-like method to calculate, ground and excited, fermionic 'solvent' wave-functions and applied to {sup 3}He{sub N} clusters with atomic or molecular impurities [J. Chem. Phys. (Communication) 125, 221101 (2006)]. The main difficulty in handling doped {sup 3}He{sub N} clusters lies in the Fermi-Dirac nuclear statistics, the wide amplitudes of the He-dopant and He-He motions, and the hard-core He-He interaction at short distances. This paper overviews the theoretical approach and its recent applications to energetic, structural and spectroscopic aspects of different dopant-{sup 3}He{sub N} clusters. Preliminary results by using the latest version of the FCI-NO computational implementation, to bosonic Cl{sub 2}(X)-({sup 4}He){sub N} clusters, are also shown.

  1. Materials interactions relating to long-term geologic disposal of nuclear waste glass

    International Nuclear Information System (INIS)

    Bibler, N.E.; Jantzen, C.M.

    1987-01-01

    In the geologic disposal of nuclear waste glass, the glass will eventually interact with groundwater in the repository system. Interactions can also occur between the glass and other waste package materials that are present. These include the steel canister that holds the glass, the metal overpack over the canister, backfill materials that may be used, and the repository host rock. This review paper systematizes the additional interactions that materials in the waste package will impose on the borosilicate glass waste form-groundwater interactions. The repository geologies reviewed are tuff, salt, basalt, and granite. The interactions emphasized are those appropriate to conditions expected after repository closure, e.g. oxic vs anoxic conditions. Whenever possible, the effect of radiation from the waste form on the interactions is examined. The interactions are evaluated based on their effect on the release and speciation of various elements including radionuclides from the glass. It is noted when further tests of repository interactions are needed before long-term predictions can be made. 63 references, 1 table

  2. Non-statistical fluctuations in fragmentation of target nuclei in high energy nuclear interactions

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Dipak; Ghosh, Premomoy; Ghosh, Alokananda; Roy, Jaya [Jadavpur Univ., Calcutta (India)

    1994-07-01

    Analysis of target fragmented ''black'' particles in nuclear emulsion from high energy relativistic interactions initiated by [sup 16]O at 2.1 GeV/nucleon and [sup 12]C and [sup 24]Mg at 4.5 GeV/nucleon reveal the existence of non-statistical fluctuations in the azimuthal plane of interaction. The asymmetry or the non-statistical fluctuations, while found to be independent of projectile mass or incident energy, are dependent on the excitation energy of the target nucleus. (Author).

  3. Non-statistical fluctuations in fragmentation of target nuclei in high energy nuclear interactions

    International Nuclear Information System (INIS)

    Ghosh, Dipak; Ghosh, Premomoy; Ghosh, Alokananda; Roy, Jaya

    1994-01-01

    Analysis of target fragmented ''black'' particles in nuclear emulsion from high energy relativistic interactions initiated by 16 O at 2.1 GeV/nucleon and 12 C and 24 Mg at 4.5 GeV/nucleon reveal the existence of non-statistical fluctuations in the azimuthal plane of interaction. The asymmetry or the non-statistical fluctuations, while found to be independent of projectile mass or incident energy, are dependent on the excitation energy of the target nucleus. (Author)

  4. Measurement of Nuclear Interaction Rates in Crystal Using the CERN-SPS North Area Test Beams

    CERN Document Server

    Losito, R; Taratin, A

    2010-01-01

    A number of tests were performed in the North area of the SPS in view of investigating crystal-particles interactions for future application in hadron colliders. The rate of nuclear interactions was measured with 400 GeV proton beams directed into a silicon bent crystal. In this way the background induced by the crystal either in amorphous or in channeling orientation was revealed. The results provide fundamental information to put in perspective the use of silicon crystals to assist halo collimation in hadron colliders, whilst minimizing the induced loss.

  5. Percolation Model of Nuclear Multifragmentation in High Energy Nucleus-Nucleus Interactions

    International Nuclear Information System (INIS)

    Abdel-Waged, Kh.

    1994-01-01

    A hybrid model based on Reggeon theory inspired model of nuclear distribution, which was successful in explaining the cascading of particles in high energy nucleus-nucleus interactions, and percolation model is proposed. In the framework of this model the yield of the fragment in p + Ag, Au at 350 GeV and C + Ag, Au at 3.6 GeV/nucleon as well as the charge distribution of fragments in Kr, Xe and U interactions with emulsion at ∼ 1 GeV/nucleon is correctly described. 32 refs., 3 figs

  6. Interaction between core analysis methodology and nuclear design: some PWR examples

    International Nuclear Information System (INIS)

    Rothleder, B.M.; Eich, W.J.

    1982-01-01

    The interaction between core analysis methodology and nuclear design is exemplified by PSEUDAX, a major improvement related to the Advanced Recycle methodology program (ARMP) computer code system, still undergoing development by the Electric Power Research Institute. The mechanism of this interaction is explored by relating several specific nulcear design changes to the demands placed by these changes on the ARMP system, and by examining the meeting of these demands, first within the standard ARMP methodology and then through augmentation of the standard methodology by development of PSEUDAX

  7. On evaluation of the nuclear interaction effect on muon sticking in μ-catalyzed dt synthesis

    International Nuclear Information System (INIS)

    Khiger, L.Ya.

    1994-01-01

    The effect of nucler interaction on the muon -alpha-particle sticking coefficient is considered on the basis of the previously developed formalism of description of the deuterium and tritium nuclei muon catalysed fusion. The account of Coulomb interaction between the muon and nuclear subsystem in the intermediate state is shown to change substantially this coefficient. The results of numerical calculations of the sticking coefficient are presented, the value of the coefficient turns out to be 3 - 4% higher than that found in the sudden approximation

  8. Double-Lambda hypernuclei and the nuclear medium effective Lambda Lambda interaction

    OpenAIRE

    Caro, José; García Recio, Carmen; Nieves Pamplona, Juan Miguel

    1999-01-01

    We fit the $^1 S_0 \\Lambda\\Lambda$ interaction in the nuclear medium to the masses of the experimentally known double-$\\Lambda$ hypernuclei: $^{\\phantom{6}6}_{\\Lambda\\Lambda}$He, $^{10}_{\\Lambda\\Lambda}$Be and $^{13}_{\\Lambda\\Lambda}$B. We derive this effective interaction from OBE J\\"ulich $\\Lambda\\Lambda$-type potentials and using both Hartree-Fock and variational approaches. We find that the inclusion of $\\Lambda\\Lambda$ correlations in the variational scheme leads to significant differenc...

  9. In-medium eta N interactions and eta nuclear bound states

    Czech Academy of Sciences Publication Activity Database

    Cieplý, Aleš; Friedman, E.; Gal, A.; Mareš, Jiří

    2014-01-01

    Roč. 925, MAY (2014), s. 126-140 ISSN 0375-9474 R&D Projects: GA ČR(CZ) GAP203/12/2126; GA MŠk LG14038 Institutional support: RVO:61389005 Keywords : N(star) (1535 resonance * meson-baryon interactions * mesons in nuclear matter * mesic nuclei Subject RIV: BE - Theoretical Physics Impact factor: 2.202, year: 2014

  10. Nuclear quadrupole interactions in ferroelectric compounds of HF/sup 181/

    Energy Technology Data Exchange (ETDEWEB)

    Kunzler, J V

    1971-01-01

    Measurements of nuclear quadrupole interaction constants in perovkite-type compounds of PbHfO/sub 3/, SnhfO/sub 3/, CaHfO/sub 3/ e SrHfO/sub 3/ have been performed using the perturbed angular correlation technique. A range of fundamental frequencies from 150 to 550 Megaradians per second was determined. The variation of quadrupole constants has been discussed through the molecular orbital theory.

  11. The proteins of intra-nuclear bodies: a data-driven analysis of sequence, interaction and expression

    Directory of Open Access Journals (Sweden)

    Bodén Mikael

    2010-04-01

    Full Text Available Abstract Background Cajal bodies, nucleoli, PML nuclear bodies, and nuclear speckles are morpohologically distinct intra-nuclear structures that dynamically respond to cellular cues. Such nuclear bodies are hypothesized to play important regulatory roles, e.g. by sequestering and releasing transcription factors in a timely manner. While the nucleolus and nuclear speckles have received more attention experimentally, the PML nuclear body and the Cajal body are still incompletely characterized in terms of their roles and protein complement. Results By collating recent experimentally verified data, we find that almost 1000 proteins in the mouse nuclear proteome are known to associate with one or more of the nuclear bodies. Their gene ontology terms highlight their regulatory roles: splicing is confirmed to be a core activity of speckles and PML nuclear bodies house a range of proteins involved in DNA repair. We train support-vector machines to show that nuclear proteins contain discriminative sequence features that can be used to identify their intra-nuclear body associations. Prediction accuracy is highest for nucleoli and nuclear speckles. The trained models are also used to estimate the full protein complement of each nuclear body. Protein interactions are found primarily to link proteins in the nuclear speckles with proteins from other compartments. Cell cycle expression data provide support for increased activity in nucleoli, nuclear speckles and PML nuclear bodies especially during S and G2 phases. Conclusions The large-scale analysis of the mouse nuclear proteome sheds light on the functional organization of physically embodied intra-nuclear compartments. We observe partial support for the hypothesis that the physical organization of the nucleus mirrors functional modularity. However, we are unable to unambiguously identify proteins' intra-nuclear destination, suggesting that critical drivers behind of intra-nuclear translocation are yet to

  12. Exploring Light’s Interactions with Bubbles and Light Absorbers in Photoelectrochemical Devices using Ray Tracing

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, John Colby [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). The Joint Center for Artificial Photosynthesis; Univ. of California, Berkeley, CA (United States). Dept. of Mechanical Engineering

    2012-12-01

    Ray tracing was used to perform optical optimization of arrays of photovoltaic microrods and explore the interaction between light and bubbles of oxygen gas on the surface of the microrods. The incident angle of light was varied over a wide range. The percent of incident light absorbed by the microrods and reflected by the bubbles was computed over this range. It was found that, for the 10 μm diameter, 100 μm tall SrTiO3 microrods simulated in the model, the optimal center-­to-­center spacing was 14 μm for a square grid. This geometry produced 75% average and 90% maximum absorbance. For a triangular grid using the same microrods, the optimal center-­to-­center spacing was 14 μm. This geometry produced 67% average and 85% maximum absorbance. For a randomly laid out grid of 5 μm diameter, 100 μm tall SrTiO3 microrods with an average center-­to-­center spacing of 20 μm, the average absorption was 23% and the maximum absorption was 43%. For a 50% areal coverage fraction of bubbles on the absorber surface, between 2%-­20% of the incident light energy was reflected away from the rods by the bubbles, depending upon incident angle and bubble morphology.

  13. Heliospheric current sheet and effects of its interaction with solar cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Malova, H. V., E-mail: hmalova@yandex.ru [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation); Popov, V. Yu.; Grigorenko, E. E.; Dunko, A. V.; Petrukovich, A. A. [Russian Academy of Sciences, Space Research Institute (Russian Federation)

    2016-08-15

    The effects of interaction of solar cosmic rays (SCRs) with the heliospheric current sheet (HCS) in the solar wind are analyzed. A self-consistent kinetic model of the HCS is developed in which ions with quasiadiabatic dynamics can present. The HCS is considered an equilibrium embedded current structure in which two main plasma species with different temperatures (the low-energy background plasma of the solar wind and the higher energy SCR component) contribute to the current. The obtained results are verified by comparing with the results of numerical simulations based on solving equations of motion by the particle tracing method in the given HCS magnetic field with allowance for SCR particles. It is shown that the HCS is a relatively thin multiscale current configuration embedded in a thicker plasma layer. In this case, as a rule, the shear (tangential to the sheet current) component of the magnetic field is present in the HCS. Taking into account high-energy SCR particles in the HCS can lead to a change of its configuration and the formation of a multiscale embedded structure. Parametric family of solutions is considered in which the current balance in the HCS is provided at different SCR temperatures and different densities of the high-energy plasma. The SCR densities are determined at which an appreciable (detectable by satellites) HCS thickening can occur. Possible applications of this modeling to explain experimental observations are discussed.

  14. An interactive gamma-ray burst educational text for the world wide-web

    Science.gov (United States)

    Horack, John M.; Rizvi, Sherene; Friend, Labraunna

    1996-08-01

    In order to strengthen education and scientific literacy among the general public, it is important to communicate the results NASA has obtained, as well as the excitement of doing world-class science. The NASA Strategic Plan specifically mandates that new opportunities and pathways be found to disseminate scientific information for consumption by the general public. We therefore announce the release of A Major League Puzzle, an interactive educational text for the WWW. A Major League Puzzle is a seven-chapter introduction to the gamma-ray burst phenomenon presented to the user through the paradigms of baseball. This resource is intended for the general public who are interested in but have not received specific training in the sciences, and is targeted to reach students at the high-school level. Using a Web-browser program such as Netscape or Mosaic, A Major League Puzzle can be accessed at ``http://wwwssl.msfc.nasa.gov/ssl/pad/astro/batse/foreword.htm.'' This work is one product of the Summer High School Apprenticeship Research Program (SHARP) conducted at the Marshall Space Flight Center in the Summer of 1995.

  15. The search for primary particle tracks in nucleon-nucleus interactions with gamma ray energy ΣEγ ≥ 3 TeV registered in stratospheric X-ray emulsion chambers using data of the RUNJOB experiment

    Directory of Open Access Journals (Sweden)

    Zayarnaya I.S.

    2017-01-01

    Full Text Available We present here the result of a retreatment of data from the RUNJOB (RUssia-Nippon JOint Balloon experiment of nucleon-nucleus interactions registered in stratospheric X-ray emulsion chambers (REC using a new method for searching and tracing of galactic particles in nuclear emulsions. In about halfcof these interactions (∼ 50 recorded in REC RUNJOB‘96-3B, RUNJOB‘97-6A and RUNJOB‘99-11A,B with energy released in the electromagnetic component ΣEγ ≥ 3 TeV and ΣEγ ≥ 5 TeV respectively, single charged particle tracks are not found within the search area defined individually by the particle track location accuracy. The absence of primary proton tracks is consistent with the original treatment of the RUNJOB experimental data. There is a difference in the zenith angular distribution for two groups of events in which a single charged particle track is observed or absent. The average penetration depth of the primary particles in REC to the interaction vertex in the zenith angle range from 60∘ to 79∘ differs by a factor two for these groups.

  16. Effects of nuclear structure in the spin-dependent scattering of weakly interacting massive particles

    Science.gov (United States)

    Nikolaev, M. A.; Klapdor-Kleingrothaus, H. V.

    1993-06-01

    We present calculations of the nuclear from factors for spin-dependent elastic scattering of dark matter WIMPs from123Te and131Xe isotopes, proposed to be used for dark matter detection. A method based on the theory of finite Fermi systems was used to describe the reduction of the single-particle spin-dependent matrix elements in the nuclear medium. Nucleon single-particle states were calculated in a realistic shell model potential; pairing effects were treated within the BCS model. The coupling of the lowest single-particle levels in123Te to collective 2+ excitations of the core was taken into account phenomenologically. The calculated nuclear form factors are considerably less then the single-particle ones for low momentum transfer. At high momentum transfer some dynamical amplification takes place due to the pion exchange term in the effective nuclear interaction. But as the momentum transfer increases, the difference disappears, the momentum transfer increases and the quenching effect disappears. The shape of the nuclear form factor for the131Xe isotope differs from the one obtained using an oscillator basis.

  17. Effects of nuclear structure in the spin-dependent scattering of weakly interacting massive particles

    International Nuclear Information System (INIS)

    Nikolaev, M.A.; Klapdor-Kleingrothaus, H.V.

    1993-01-01

    We present calculations of the nuclear from factors for spin-dependent elastic scattering of dark matter WIMPs from 123 Te and 131 Xe isotopes, proposed to be used for dark matter detection. A method based on the theory of finite Fermi systems was used to describe the reduction of the single-particle spin-dependent matrix elements in the nuclear medium. Nucelon single-particle states were calculated in a realistic shell model potential; pairing effects were treated within the BCS model. The coupling of the lowest single-particle levels in 123 Te to collective 2 + excitations of the core was taken into account phenomenologically. The calculated nuclear form factors are considerably less then the single-particle ones for low momentum transfer. At high momentum transfer some dynamical amplification takes place due to the pion exchange term in the effective nuclear interaction. But as the momentum transfer increases, the difference disappears, the momentum transfer increases and quenching effect disappears. The shape of the nuclear form factor for the 131 Xe isotope differs from the one obtained using an oscillator basis. (orig.)

  18. New approach to the interaction of cosmic rays with nuclei in spacecraft shielding and the human body

    International Nuclear Information System (INIS)

    Bush, B.W.; Nix, J.R.

    1993-01-01

    The interaction of high-energy cosmic rays with nuclei in spacecraft shielding and the human body is important for manned interplanetary missions and is not well understood either experimentally or theoretically. We present a new theoretical approach to this problem based on classical hadrodynamics for extended nucleons, which treats nucleons of finite size interacting with massive meson fields. This theory represents the classical analogue of the quantum hadrodynamics of Serot and Walecka without the assumptions of the mean-field approximation and point nucleons. It provides a natural covariant microscopic approach to collisions between cosmic rays and nuclei that automatically includes space-time non-locality and retardation, nonequilibrium phenomena, interactions among all nucleons, and particle production. Unlike previous models, this approach is manifestly Lorentz covariant and satisfies a priori the basic conditions that are present when cosmic rays collide with nuclei, namely an interaction time that is extremely short and a nucleon mean-free path, force range, and internucleon separation that are all comparable in size. We review the history of classical meson-field theory and derive the classical relativistic equations of motion for nucleons of finite size interacting with massive scalar and vector meson fields

  19. Time resolved, 2-D hard X-ray imaging of relativistic electron-beam target interactions on ETA-II

    International Nuclear Information System (INIS)

    Crist, C.E.; Sampayan, S.; Westenskow, G.; Caporaso, G.; Houck, T.; Weir, J.; Trimble, D.; Krogh, M.

    1998-01-01

    Advanced radiographic applications require a constant source size less than 1 mm. To study the time history of a relativistic electron beam as it interacts with a bremsstrahlung converter, one of the diagnostics they use is a multi-frame time-resolved hard x-ray camera. They are performing experiments on the ETA-II accelerator at Lawrence Livermore National Laboratory to investigate details of the electron beam/converter interactions. The camera they are using contains 6 time-resolved images, each image is a 5 ns frame. By starting each successive frame 10 ns after the previous frame, they create a 6-frame movie from the hard x-rays produced from the interaction of the 50-ns electron beam pulse

  20. No interaction between X-ray induced lesions in maternal and paternal chromosomes in inseminated eggs of Drosophila melanogaster

    International Nuclear Information System (INIS)

    Wuergler, F.E.; Graf, U.; Jeanneret, P.

    1978-01-01

    X-ray induced premutational lesions persist in mature gametes of drosophila until fertilization. Repairable lesions in sperm and oocyte chromosomes are repaired exclusively by maternal repair systems in the inseminated egg. Interactions between irradiated genomes in inseminated eggs might result in additional lethality if breaks induced in separate nuclei, which would normally be repaired, could interact to form dicentric chromosomes. Adult drosophila flies were X-irradiated (up to 5 kR), individual females crossed to three or four males, and the dose-response curves for dominant lethals (embryonic lethality) compared. The results indicate thet the potentially lethal damage present in irradiated sperm chromosomes was expressed independently of whether or not the oocyte was also irradiated. There were no (or only very few) interactions between maternal and paternal chromosome complements, and the maternal repair systems acting on radiation-induced chromosome breaks in sperm were resistant to X-rays. (U.K.)

  1. A new method for imaging nuclear threats using cosmic ray muons

    OpenAIRE

    Morris, C. L.; Bacon, Jeffrey; Borozdin, Konstantin; Miyadera, Haruo; Perry, John; Rose, Evan; Watson, Scott; White, Timothy; Aberle, Derek; Green, J. Andrew; McDuff, George G.; Lukić, Zarija; Milner, Edward C.

    2013-01-01

    Muon tomography is a technique that uses cosmic ray muons to generate three dimensional images of volumes using information contained in the Coulomb scattering of the muons. Advantages of this technique are the ability of cosmic rays to penetrate significant overburden and the absence of any additional dose delivered to subjects under study above the natural cosmic ray flux. Disadvantages include the relatively long exposure times and poor position resolution and complex algorithms needed for...

  2. Education and training of future nuclear engineers through the use of an interactive plant simulator

    International Nuclear Information System (INIS)

    Ahnert, C.; Cuervo, D.; Garcia-Herranz, N.; Aragones, J.M.; Cabellos, O.; Gallego, E.; Minguez, E.; Lorente, A.; Piedra, D.; Rebollo, L.; Blanco, J.

    2010-01-01

    The International Atomic Energy Agency (IAEA) sponsors the development of nuclear reactor simulators for education, or arranges the supply of such simulation programs. Aware of this, the Department of Nuclear Engineering of the Universidad Politecnica de Madrid was provided in 2008 with the Interactive Graphical Simulator of the Spanish nuclear power plant Jose Cabrera, whose operation ceased definitively in 2006. According with the IAEA-TECDOC- 1411, the simulator is a Graphical Simulator, used for training of main control room personnel, technical support engineers, and operations management. This paper presents all the work performed at the Department to turn the simulator into a teaching/learning tool, to be use in the nuclear engineering studies following guidance found in: Shtub, A. Parush, T.T. Hewett 'The use of simulation in learning and teaching' (Int. J. Eng. Educ., 25(2), 2009, pp. 206-208). The experience obtained so far with the use of the simulator has been very successful. The graduate students involved in the development of the projects, practices and documents related with the simulator show a great interest for the work that they are doing making that the laboratory where the simulator is installed to be busy place. Regarding the undergraduate students, the practices in the simulator encourage them to follow the Nuclear Energy studies in the Engineering Schools, what is very rewarding for the Department professors. The simulator has proved to be an optimal tool to transfer the knowledge of the physical phenomena that are involved in the nuclear power plants, from the nuclear reactor to the whole set of systems and equipments on a nuclear power plant. It is also a relevant tool for motivation of the students, and to complete the theoretical lessons. This use of the simulator in the learning-teaching process meats also the criteria recommended for the Bologna adapted studies, as it helps to increase the private hands-on work of the student, and

  3. Study by nuclear techniques of the impurity-defect interaction in implanted metals

    International Nuclear Information System (INIS)

    Thome, Lionel.

    1978-01-01

    The properties of out equilibrium alloys formed by impurity implantation are strongly influenced by radiation damage created during implantation. This work presents a study, via hyperfine interaction and lattice location experiments, of the impurity-defect interaction in ion implanted metals. When the impurity and defect concentrations in the implanted layer are small, i.e. when impurities are uniformly recoil implanted in the whole crystal volume following a nuclear reaction (Aq In experiments), the impurity interacts with its own damage cascade. In this case, a vacancy is found to be trapped by a fraction of impurities during an athermal process. The value of this fraction does not seem to depend critically on impurity and host. When the impurity and defect concentrations are such that defect cascades interact, i.e. when impurities are implanted with an isotope separator (Fe Yb experiments), the observed impurity-vacancy (or vacancy cluster) interactions depend then strongly on the nature of impurity and host. An empirical relation, which indicates the importance of elastic effects, has been found between the proportion of impurities interacting with defects and the difference between impurity and host atom radii. At implantation temperature such that vacancies are mobile, the impurity-defect interaction depends essentially on vacancy migration. A model based on chemical kinetics has been developed to account for the variation with temperature of measured quantities [fr

  4. Influence of nuclear interactions in body tissues on tumor dose in carbon-ion radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Inaniwa, T., E-mail: taku@nirs.go.jp; Kanematsu, N. [Medical Physics Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555 (Japan); Tsuji, H.; Kamada, T. [Hospital, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

    2015-12-15

    Purpose: In carbon-ion radiotherapy treatment planning, the planar integrated dose (PID) measured in water is applied to the patient dose calculation with density scaling using the stopping power ratio. Since body tissues are chemically different from water, this dose calculation can be subject to errors, particularly due to differences in inelastic nuclear interactions. In recent studies, the authors proposed and validated a PID correction method for these errors. In the present study, the authors used this correction method to assess the influence of these nuclear interactions in body tissues on tumor dose in various clinical cases. Methods: Using 10–20 cases each of prostate, head and neck (HN), bone and soft tissue (BS), lung, liver, pancreas, and uterine neoplasms, the authors first used treatment plans for carbon-ion radiotherapy without nuclear interaction correction to derive uncorrected dose distributions. The authors then compared these distributions with recalculated distributions using the nuclear interaction correction (corrected dose distributions). Results: Median (25%/75% quartiles) differences between the target mean uncorrected doses and corrected doses were 0.2% (0.1%/0.2%), 0.0% (0.0%/0.0%), −0.3% (−0.4%/−0.2%), −0.1% (−0.2%/−0.1%), −0.1% (−0.2%/0.0%), −0.4% (−0.5%/−0.1%), and −0.3% (−0.4%/0.0%) for the prostate, HN, BS, lung, liver, pancreas, and uterine cases, respectively. The largest difference of −1.6% in target mean and −2.5% at maximum were observed in a uterine case. Conclusions: For most clinical cases, dose calculation errors due to the water nonequivalence of the tissues in nuclear interactions would be marginal compared to intrinsic uncertainties in treatment planning, patient setup, beam delivery, and clinical response. In some extreme cases, however, these errors can be substantial. Accordingly, this correction method should be routinely applied to treatment planning in clinical practice.

  5. High resolution γ spectra of 40-44 MeV γ photon activation products: Part 3 - a summary of γ rays, radionuclides and nuclear interferences observed

    International Nuclear Information System (INIS)

    Williams, D.R.; Hislop, J.S.

    1980-09-01

    A table of γ rays observed in the high resolution γ ray spectra of 40 to 44 MeV γ photon activation products is presented. This table is arranged in order of increasing γ ray energy and the parent isotopes, their half-lives and their inactive precursors are identified. Nuclear interferences caused by production of an active isotope from different parent elements have been identified and evaluated quantitatively. These are also tabulated. (author)

  6. Soil-structure interaction in nuclear power plants: a comparison of methods

    International Nuclear Information System (INIS)

    Wight, L.H.

    1976-06-01

    We performed an extensive parametric survey to analyze the differences between two methods of calculating soil-structure interaction. One method involves discretizing the soil-structure system and solving for the complete response with the LUSH computer code. The other method solves for the lumped mass structural response with Whitman soil springs. Twelve soil-structure interaction problems are solved by each of these methods. Representative results are presented and discussed. The debate within the nuclear industry in the United States over the relative merits of various methods of calculating soil-structure interaction has intensified over the last three years. The debate is largely the result of the U.S. Nuclear Regulatory Commission's position generally favoring the finite element approach. Certain sectors of the industry claim that this ruling is without technical basis, that it requires unnecessary expense, and that it inhibits the judgment of the analyst. We have addressed each of these points through lumped mass and finite element calculations on a set of twelve soil-structure interaction problems. The results of these calculations indicate some of the consequences of the choice of method

  7. Radiation interaction with substance and simulation of the nuclear geophysical problems

    International Nuclear Information System (INIS)

    Pshenichnyj, G.A.

    1982-01-01

    Main processes of interaction of various types of nuclear radiation (NR) with substance, NR transport theory and physical- mathematical simulation of basic problems of nuclear geophysics (NG) are considered. General classification of NG methods according to the type of the detected radiation with a more detailed division according to the physical essence of the interaction process employed is given. Direct NG problems are related to the study of space- energy radiation distribution in substance under certain cross sections of elementary interaction processes, substance properties and specified geometric conditions. The theoretical solution of the direct problems is based on using mathematical models of radiation transport in specified media. The NG inverse problems consist in determining element composition and other medium properties by data of integral or spectral characteristics of NR fields measurements. The NR in the course of its transport in substance can experience dozens of elementary interaction processes, the predominance of this or that process depending on NR energy, medium properties and geometric measurement conditions. This explains a wide NG method diversity. The Monte Carlo method application in the NR transport theory and various methods of decreasing calculations labour input are considered [ru

  8. Computerized tomography with X-rays: an instrument in the analysis physico-chemical between formations and drilling fluids interactions

    International Nuclear Information System (INIS)

    Coelho, Marcus Vinicius Cavalcante

    1998-01-01

    In this study it is demonstrated the applicability of the Computerized Tomography technique with x-rays to evaluate the reactivity degree between various drilling fluids and argillaceous sediments (Shales and Sandstones). The research has been conducted in the Rock-Fluid Interaction Pressure Simulator (RFIPS), where the possible physico-chemical alterations can be observed through successive tomography images, which are obtained during the flow of the fluid through the samples. In addition, it was noticed the formation of mud cake in Berea Sandstones samples in the RFIPS, though the Computerized Tomography with X-rays, when utilizing drilling fluids weighted with the baryte. (author)

  9. Microorganisms in potential host rocks for geological disposal of nuclear waste and their interactions with radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Cherkouk, A.; Liebe, M.; Luetke, L.; Moll, H.; Stumpf, T. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Resource Ecology

    2015-07-01

    The long-term safety of nuclear waste in a deep geological repository is an important issue in our society. Microorganisms indigenous to potential host rocks are able to influence the oxidation state, speciation and therefore the mobility of radionuclides as well as gas generation or canister corrosion. Therefore, for the safety assessment of such a repository it is necessary to know which microorganisms are present in the potential host rocks (e.g. clay, salt) and if these microorganisms can influence the performance of a repository. Microbial diversity in potential host rocks for geological disposal of nuclear waste was analyzed by culture-independent molecular biological methods (e.g. 16S rRNA gene retrieval) as well as enrichment and isolation of indigenous microbes. Among other isolates, a Paenibacillus strain, as a representative of Firmicutes, was recovered in R2A media under anaerobic conditions from Opalinus clay from the Mont Terri in Switzerland. Accumulation experiments and potentiometric titrations showed a strong interaction of Paenibacillus sp. cells with U(VI) within a broad pH range (3-7). Additionally, the interactions of the halophilic archaeal strain Halobacterium noricense DSM 15987, a salt rock representative reference strain, with U(VI) at high ionic strength was investigated. After 48 h the cells were still alive at uranium concentrations up to 60 μM, which demonstrates that Halobacterium noricense can tolerate uranium concentrations up to this level. The formed uranium sorption species were examined with time-resolved laser-induced fluorescence spectroscopy (TRLFS). The results about the microbial communities present in potential host rocks for nuclear waste repositories and their interactions with radionuclides contribute to the safety assessment of a prospective nuclear waste repository.

  10. Interaction of HTLV-1 Tax protein with calreticulin: implications for Tax nuclear export and secretion.

    Science.gov (United States)

    Alefantis, Timothy; Flaig, Katherine E; Wigdahl, Brian; Jain, Pooja

    2007-05-01

    Human T cell leukemia virus type 1 (HTLV-1) is the etiologic agent of adult T cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The HTLV-1 transcriptional transactivator protein Tax plays an integral role in virus replication and disease progression. Traditionally, Tax is described as a nuclear protein where it performs its primary role as a transcriptional transactivator. However, recent studies have clearly shown that Tax can also be localized to the cytoplasm where it has been shown to interact with a number of host transcription factors most notably NF-kappaB, constitutive expression of which is directly related to the T cell transforming properties of Tax in ATL patients. The presence of a functional nuclear export signal (NES) within Tax and the secretion of full-length Tax have also been demonstrated previously. Additionally, release of Tax from HTLV-1-infected cells and the presence of cell-free Tax was demonstrated in the CSF of HAM/TSP patients suggesting that the progression to HAM/TSP might be mediated by the ability of Tax to function as an extracellular cytokine. Therefore, in both ATL and HAM/TSP Tax nuclear export and nucleocytoplasmic shuttling may play a critical role, the mechanism of which remains unknown. In this study, we have demonstrated that the calcium binding protein calreticulin interacts with Tax by co-immunoprecipitation. This interaction was found to localize to a region at or near the nuclear membrane. In addition, differential expression of calreticulin was demonstrated in various cell types that correlated with their ability to retain cytoplasmic Tax, particularly in astrocytes. Finally, a comparison of a number of HTLV-1-infected T cell lines to non-infected T cells revealed higher expression of calreticulin in infected cells implicating a direct role for this protein in HTLV-1 infection.

  11. Microorganisms in potential host rocks for geological disposal of nuclear waste and their interactions with radionuclides

    International Nuclear Information System (INIS)

    Cherkouk, A.; Liebe, M.; Luetke, L.; Moll, H.; Stumpf, T.

    2015-01-01

    The long-term safety of nuclear waste in a deep geological repository is an important issue in our society. Microorganisms indigenous to potential host rocks are able to influence the oxidation state, speciation and therefore the mobility of radionuclides as well as gas generation or canister corrosion. Therefore, for the safety assessment of such a repository it is necessary to know which microorganisms are present in the potential host rocks (e.g. clay, salt) and if these microorganisms can influence the performance of a repository. Microbial diversity in potential host rocks for geological disposal of nuclear waste was analyzed by culture-independent molecular biological methods (e.g. 16S rRNA gene retrieval) as well as enrichment and isolation of indigenous microbes. Among other isolates, a Paenibacillus strain, as a representative of Firmicutes, was recovered in R2A media under anaerobic conditions from Opalinus clay from the Mont Terri in Switzerland. Accumulation experiments and potentiometric titrations showed a strong interaction of Paenibacillus sp. cells with U(VI) within a broad pH range (3-7). Additionally, the interactions of the halophilic archaeal strain Halobacterium noricense DSM 15987, a salt rock representative reference strain, with U(VI) at high ionic strength was investigated. After 48 h the cells were still alive at uranium concentrations up to 60 μM, which demonstrates that Halobacterium noricense can tolerate uranium concentrations up to this level. The formed uranium sorption species were examined with time-resolved laser-induced fluorescence spectroscopy (TRLFS). The results about the microbial communities present in potential host rocks for nuclear waste repositories and their interactions with radionuclides contribute to the safety assessment of a prospective nuclear waste repository.

  12. Thermoluminescence dosimetry of gamma rays from the fallout of the Semipalatinsk nuclear tests

    International Nuclear Information System (INIS)

    Takada, J.; Hoshi, M.; Endo, S.; Yamamoto, M.; Nagatomo, T.; Gusev, B.I.; Rozenson, R.I.; Apsalikov, K.N.; Tchaijunusova, N.J.

    1996-01-01

    Field missions were sent to several settlements near the Semipalatinsk nuclear test site out in order to investigate dosimetry for the residents in 1995. The results of measurements of environmental radiation doses and thermoluminescence dosimetry in some villages near the Semipalatinsk nuclear test site are presented. The radiation levels in several villages are the natural background level in 1995, 6 years after the final nuclear explosion. On the other hand, thermoluminescence dosimetry revealed significant radiation exposure to residents in this area due to nuclear tests. (author)

  13. Nuclear import of transcription factor BR-C is mediated by its interaction with RACK1.

    Science.gov (United States)

    Cheng, Daojun; Qian, Wenliang; Wang, Yonghu; Meng, Meng; Wei, Ling; Li, Zhiqing; Kang, Lixia; Peng, Jian; Xia, Qingyou

    2014-01-01

    The transcription factor Broad Complex (BR-C) is an early ecdysone response gene in insects and contains two types of domains: two zinc finger domains for the activation of gene transcription and a Bric-a-brac/Tramtrack/Broad complex (BTB) domain for protein-protein interaction. Although the mechanism of zinc finger-mediated gene transcription is well studied, the partners interacting with the BTB domain of BR-C has not been elucidated until now. Here, we performed a yeast two-hybrid screen using the BTB domain of silkworm BR-C as bait and identified the receptor for activated C-kinase 1 (RACK1), a scaffolding/anchoring protein, as the novel partner capable of interacting with BR-C. The interaction between BR-C and RACK1 was further confirmed by far-western blotting and pull-down assays. Importantly, the disruption of this interaction, via RNAi against the endogenous RACK1 gene or deletion of the BTB domain, abolished the nuclear import of BR-C in BmN4 cells. In addition, RNAi against the endogenous PKC gene as well as phosphorylation-deficient mutation of the predicted PKC phosphorylation sites at either Ser373 or Thr406 in BR-C phenocopied RACK1 RNAi and altered the nuclear localization of BR-C. However, when BTB domain was deleted, phosphorylation mimics of either Ser373 or Thr406 had no effect on the nuclear import of BR-C. Moreover, mutating the PKC phosphorylation sites at Ser373 and Thr406 or deleting the BTB domain significantly decreased the transcriptional activation of a BR-C target gene. Given that RACK1 is necessary for recruiting PKC to close and phosphorylate target proteins, we suggest that the PKC-mediated phosphorylation and nuclear import of BR-C is determined by its interaction with RACK1. This novel finding will be helpful for further deciphering the mechanism underlying the role of BR-C proteins during insect development.

  14. Nuclear import of transcription factor BR-C is mediated by its interaction with RACK1.

    Directory of Open Access Journals (Sweden)

    Daojun Cheng

    Full Text Available The transcription factor Broad Complex (BR-C is an early ecdysone response gene in insects and contains two types of domains: two zinc finger domains for the activation of gene transcription and a Bric-a-brac/Tramtrack/Broad complex (BTB domain for protein-protein interaction. Although the mechanism of zinc finger-mediated gene transcription is well studied, the partners interacting with the BTB domain of BR-C has not been elucidated until now. Here, we performed a yeast two-hybrid screen using the BTB domain of silkworm BR-C as bait and identified the receptor for activated C-kinase 1 (RACK1, a scaffolding/anchoring protein, as the novel partner capable of interacting with BR-C. The interaction between BR-C and RACK1 was further confirmed by far-western blotting and pull-down assays. Importantly, the disruption of this interaction, via RNAi against the endogenous RACK1 gene or deletion of the BTB domain, abolished the nuclear import of BR-C in BmN4 cells. In addition, RNAi against the endogenous PKC gene as well as phosphorylation-deficient mutation of the predicted PKC phosphorylation sites at either Ser373 or Thr406 in BR-C phenocopied RACK1 RNAi and altered the nuclear localization of BR-C. However, when BTB domain was deleted, phosphorylation mimics of either Ser373 or Thr406 had no effect on the nuclear import of BR-C. Moreover, mutating the PKC phosphorylation sites at Ser373 and Thr406 or deleting the BTB domain significantly decreased the transcriptional activation of a BR-C target gene. Given that RACK1 is necessary for recruiting PKC to close and phosphorylate target proteins, we suggest that the PKC-mediated phosphorylation and nuclear import of BR-C is determined by its interaction with RACK1. This novel finding will be helpful for further deciphering the mechanism underlying the role of BR-C proteins during insect development.

  15. Direct Measurement of Nuclear Dependence of Charged Current Quasielasticlike Neutrino Interactions Using MINERvA

    Science.gov (United States)

    Betancourt, M.; Ghosh, A.; Walton, T.; Altinok, O.; Bellantoni, L.; Bercellie, A.; Bodek, A.; Bravar, A.; Cai, T.; Martinez Caicedo, D. A.; Carneiro, M. F.; Dytman, S. A.; Díaz, G. A.; Felix, J.; Fields, L.; Fine, R.; Galindo, R.; Gallagher, H.; Ghosh, A.; Golan, T.; Gran, R.; Harris, D. A.; Higuera, A.; Hurtado, K.; Kiveni, M.; Kleykamp, J.; Le, T.; Maher, E.; Manly, S.; Mann, W. A.; Marshall, C. M.; McFarland, K. S.; McGivern, C. L.; McGowan, A. M.; Messerly, B.; Miller, J.; Mislivec, A.; Morfín, J. G.; Mousseau, J.; Naples, D.; Nelson, J. K.; Norrick, A.; Nuruzzaman, Patrick, C. E.; Perdue, G. N.; Ramírez, M. A.; Ren, L.; Rimal, D.; Rodrigues, P. A.; Ruterbories, D.; Schellman, H.; Sobczyk, J. T.; Solano Salinas, C. J.; Sánchez Falero, S.; Valencia, E.; Wolcott, J.; Wospakrik, M.; Yaeggy, B.; Minerva Collaboration

    2017-08-01

    Charged-current νμ interactions on carbon, iron, and lead with a final state hadronic system of one or more protons with zero mesons are used to investigate the influence of the nuclear environment on quasielasticlike interactions. The transferred four-momentum squared to the target nucleus, Q2, is reconstructed based on the kinematics of the leading proton, and differential cross sections versus Q2 and the cross-section ratios of iron, lead, and carbon to scintillator are measured for the first time in a single experiment. The measurements show a dependence on the atomic number. While the quasielasticlike scattering on carbon is compatible with predictions, the trends exhibited by scattering on iron and lead favor a prediction with intranuclear rescattering of hadrons accounted for by a conventional particle cascade treatment. These measurements help discriminate between different models of both initial state nucleons and final state interactions used in the neutrino oscillation experiments.

  16. Assessment of soil/structure interaction analysis procedures for nuclear power plant structures

    International Nuclear Information System (INIS)

    Young, G.A.; Wei, B.C.

    1977-01-01

    The paper presents an assessment of two state-of-the-art soil/structure interaction analysis procedures that are frequently used to provide seismic analyses of nuclear power plant structures. The advantages of large three-dimensional, elastic, discrete mass models and two-dimensional finite element models are compared. The discrete mass models can provide three-dimensional response capability with economical computer costs but only fair soil/structure interaction representation. The two-dimensional finite element models provide good soil/structure interaction representation, but cannot provide out-of-plane response. Three-dimensional finite element models would provide the most informative and complete analyses. For this model, computer costs would be much greater, but modeling costs would be approximately the same as those required for three-dimensional discrete mass models

  17. Detecting Structural Damage of Nuclear Power Plant by Interactive Data Mining Approach

    International Nuclear Information System (INIS)

    Yufei Shu

    2006-01-01

    This paper presents a nonlinear structural damage identification technique, based on an interactive data mining approach, which integrates a human cognitive model in a data mining loop. A mining control agent emulating human analysts is developed, which directly interacts with the data miner, analyzing and verifying the output of the data miner and controlling the data mining process. Additionally, an artificial neural network method, which is adopted as a core component of the proposed interactive data mining method, is evolved by adding a novelty detecting and retraining function for handling complicated nuclear power plant quake-proof data. Plant quake-proof testing data has been applied to the system to show the validation of the proposed method. (author)

  18. Equations of the quasiparticle-phonon nuclear model with effective finite-rank separable interactions

    International Nuclear Information System (INIS)

    Solov'ev, V.G.

    1989-01-01

    Basic equations are derived for the quasiparticle-phonon nuclear model for the finite-rank separable isoscalar and isovector multipole and spin-multipole and isovector tensor particle-hole and particle-particle interactions between quasiparticles. For even-even spherical nuclei it is shown that in the calculation of single-phonon states in the random phase approximation a significant complication arises due to the finite rank n max >1 of separable interactions. Taking into account separable interactions with n max >1 does not lead to significant difficulties in the calculation of fragmentation of quasiparticle and collective states. It is asserted that the model can be used as a basis for calculations of many characteristics of complex nuclei

  19. Effects of isospin and momentum-dependent interactions on thermal properties of nuclear matter

    International Nuclear Information System (INIS)

    Xu Jun; Ma Hongru; Chen Liewen; Li Baoan

    2009-01-01

    In this article, three models with different isospin and momentum dependence are used to study the thermodynamical properties of asymmetric nuclear matter. They are isospin and momentum-dependent MDI interaction constrained by the isospin diffusion data of heavy ion collision, the momentum-independent MID interaction and the isoscalar momentum-dependent eMDYI interaction. Temperature effects of symmetry energy, mechanical and chemical instability and liquid-gas phase transition are analyzed. It is found that for MDI model the temperature effects of the symmetry energy attribute from both the kinetic and potential energy, while only potential part contributes to the decreasing of the symmetry energy for MID and eMDYI models. We also find that the mechanical instability, chemical instability and liquid-gas phase transition are all sensitive to the isospin and momentum dependence and the density dependence of the symmetry energy. (authors)

  20. Coordinated rates of evolution between interacting plastid and nuclear genes in Geraniaceae.

    Science.gov (United States)

    Zhang, Jin; Ruhlman, Tracey A; Sabir, Jamal; Blazier, J Chris; Jansen, Robert K

    2015-03-01

    Although gene coevolution has been widely observed within individuals and between different organisms, rarely has this phenomenon been investigated within a phylogenetic framework. The Geraniaceae is an attractive system in which to study plastid-nuclear genome coevolution due to the highly elevated evolutionary rates in plastid genomes. In plants, the plastid-encoded RNA polymerase (PEP) is a protein complex composed of subunits encoded by both plastid (rpoA, rpoB, rpoC1, and rpoC2) and nuclear genes (sig1-6). We used transcriptome and genomic data for 27 species of Geraniales in a systematic evaluation of coevolution between genes encoding subunits of the PEP holoenzyme. We detected strong correlations of dN (nonsynonymous substitutions) but not dS (synonymous substitutions) within rpoB/sig1 and rpoC2/sig2, but not for other plastid/nuclear gene pairs, and identified the correlation of dN/dS ratio between rpoB/C1/C2 and sig1/5/6, rpoC1/C2 and sig2, and rpoB/C2 and sig3 genes. Correlated rates between interacting plastid and nuclear sequences across the Geraniales could result from plastid-nuclear genome coevolution. Analyses of coevolved amino acid positions suggest that structurally mediated coevolution is not the major driver of plastid-nuclear coevolution. The detection of strong correlation of evolutionary rates between SIG and RNAP genes suggests a plausible explanation for plastome-genome incompatibility in Geraniaceae. © 2015 American Society of Plant Biologists. All rights reserved.