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Sample records for analysis nuclear reaction

  1. Multilayer network analysis of nuclear reactions

    CERN Document Server

    Zhu, Liang; Chen, Qu; Han, Ding-Ding

    2016-01-01

    The nuclear reaction network is usually studied via precise calculation of differential equation sets, and much research interest has been focused on the characteristics of nuclides, such as half-life and size limit. In this paper, however, we adopt the methods from both multilayer and reaction networks, and obtain a distinctive view by mapping all the nuclear reactions in JINA REACLIB database into a directed network with 4 layers: neutron, proton, $^4$He and the remainder. The layer names correspond to reaction types decided by the currency particles consumed. This combined approach reveals that, in the remainder layer, the $\\beta$-stability has high correlation with node degree difference and overlapping coefficient. Moreover, when reaction rates are considered as node strength, we find that, at lower temperatures, nuclide half-life scales reciprocally with its out-strength. The connection between physical properties and topological characteristics may help to explore the boundary of the nuclide chart.

  2. Multilayer Network Analysis of Nuclear Reactions.

    Science.gov (United States)

    Zhu, Liang; Ma, Yu-Gang; Chen, Qu; Han, Ding-Ding

    2016-01-01

    The nuclear reaction network is usually studied via precise calculation of differential equation sets, and much research interest has been focused on the characteristics of nuclides, such as half-life and size limit. In this paper, however, we adopt the methods from both multilayer and reaction networks, and obtain a distinctive view by mapping all the nuclear reactions in JINA REACLIB database into a directed network with 4 layers: neutron, proton, (4)He and the remainder. The layer names correspond to reaction types decided by the currency particles consumed. This combined approach reveals that, in the remainder layer, the β-stability has high correlation with node degree difference and overlapping coefficient. Moreover, when reaction rates are considered as node strength, we find that, at lower temperatures, nuclide half-life scales reciprocally with its out-strength. The connection between physical properties and topological characteristics may help to explore the boundary of the nuclide chart. PMID:27558995

  3. Multilayer Network Analysis of Nuclear Reactions

    Science.gov (United States)

    Zhu, Liang; Ma, Yu-Gang; Chen, Qu; Han, Ding-Ding

    2016-01-01

    The nuclear reaction network is usually studied via precise calculation of differential equation sets, and much research interest has been focused on the characteristics of nuclides, such as half-life and size limit. In this paper, however, we adopt the methods from both multilayer and reaction networks, and obtain a distinctive view by mapping all the nuclear reactions in JINA REACLIB database into a directed network with 4 layers: neutron, proton, 4He and the remainder. The layer names correspond to reaction types decided by the currency particles consumed. This combined approach reveals that, in the remainder layer, the β-stability has high correlation with node degree difference and overlapping coefficient. Moreover, when reaction rates are considered as node strength, we find that, at lower temperatures, nuclide half-life scales reciprocally with its out-strength. The connection between physical properties and topological characteristics may help to explore the boundary of the nuclide chart. PMID:27558995

  4. Multilayer Network Analysis of Nuclear Reactions

    Science.gov (United States)

    Zhu, Liang; Ma, Yu-Gang; Chen, Qu; Han, Ding-Ding

    2016-08-01

    The nuclear reaction network is usually studied via precise calculation of differential equation sets, and much research interest has been focused on the characteristics of nuclides, such as half-life and size limit. In this paper, however, we adopt the methods from both multilayer and reaction networks, and obtain a distinctive view by mapping all the nuclear reactions in JINA REACLIB database into a directed network with 4 layers: neutron, proton, 4He and the remainder. The layer names correspond to reaction types decided by the currency particles consumed. This combined approach reveals that, in the remainder layer, the β-stability has high correlation with node degree difference and overlapping coefficient. Moreover, when reaction rates are considered as node strength, we find that, at lower temperatures, nuclide half-life scales reciprocally with its out-strength. The connection between physical properties and topological characteristics may help to explore the boundary of the nuclide chart.

  5. Optimizing Nuclear Reaction Analysis (NRA) using Bayesian Experimental Design

    OpenAIRE

    von Toussaint, U.; Schwarz-Selinger, T.; Gori, S.

    2008-01-01

    Nuclear Reaction Analysis with ${}^{3}$He holds the promise to measure Deuterium depth profiles up to large depths. However, the extraction of the depth profile from the measured data is an ill-posed inversion problem. Here we demonstrate how Bayesian Experimental Design can be used to optimize the number of measurements as well as the measurement energies to maximize the information gain. Comparison of the inversion properties of the optimized design with standard settings reveals huge possi...

  6. Nuclear reaction analysis (NRA) for trace element detection

    Energy Technology Data Exchange (ETDEWEB)

    Doebeli, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Noll, K. [Bern Univ. (Switzerland)

    1997-09-01

    Ion beam induced nuclear reactions can be used to analyse trace element concentrations in materials. The method is especially suited for the detection of light contaminants in heavy matrices. (author) 3 figs., 2 refs.

  7. Nuclear reaction

    CERN Multimedia

    Penwarden, C

    2001-01-01

    At the European Research Organization for Nuclear Research, Nobel laureates delve into the mysteries of particle physics. But when they invited artists from across the continent to visit their site in Geneva, they wanted a new kind of experiment.

  8. Ion beam analysis - development and application of nuclear reaction analysis methods, in particular at a nuclear microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Sjoeland, K.A.

    1996-11-01

    This thesis treats the development of Ion Beam Analysis methods, principally for the analysis of light elements at a nuclear microprobe. The light elements in this context are defined as having an atomic number less than approx. 13. The work reported is to a large extent based on multiparameter methods. Several signals are recorded simultaneously, and the data can be effectively analyzed to reveal structures that can not be observed through one-parameter collection. The different techniques are combined in a new set-up at the Lund Nuclear Microprobe. The various detectors for reaction products are arranged in such a way that they can be used for the simultaneous analysis of hydrogen, lithium, boron and fluorine together with traditional PIXE analysis and Scanning Transmission Ion Microscopy as well as photon-tagged Nuclear Reaction Analysis. 48 refs.

  9. Ion beam analysis - development and application of nuclear reaction analysis methods, in particular at a nuclear microprobe

    International Nuclear Information System (INIS)

    This thesis treats the development of Ion Beam Analysis methods, principally for the analysis of light elements at a nuclear microprobe. The light elements in this context are defined as having an atomic number less than approx. 13. The work reported is to a large extent based on multiparameter methods. Several signals are recorded simultaneously, and the data can be effectively analyzed to reveal structures that can not be observed through one-parameter collection. The different techniques are combined in a new set-up at the Lund Nuclear Microprobe. The various detectors for reaction products are arranged in such a way that they can be used for the simultaneous analysis of hydrogen, lithium, boron and fluorine together with traditional PIXE analysis and Scanning Transmission Ion Microscopy as well as photon-tagged Nuclear Reaction Analysis. 48 refs

  10. Nuclear reaction analysis for composition measurement of BN thin films

    International Nuclear Information System (INIS)

    The composition of the BN film was determined using Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA). RBS can provide all the constituent concentrations in the films and the absolute determination of the number of atoms/cm2. However RBS is not suited to detection of light atoms deposited on a substrate material of higher atomic mass. On the other hand, the NRA has the advantage that it allows to measure the areal concentrations of nitrogen and boron in BNx films on Si substrates, although calibration is required using standard specimens. These experiments were carried out on the 2 MeV Van de Graaff accelerator connected to an ultra high vacuum (UHV) chamber. For RBS measurement, a 42He+ beam at 2.0 MeV, a total scattering angle of 168° and a beam incident angle to the substrate normal or 60 deg. were used. Zr and Pt films, 1150 Å to 3300 Å in thickness, deposited on vitreous carbon plates were used as a substrate. NRA was performed using a deuteron beam of 1.7 MeV and a beam incident angle of 20 deg. A peak from 10B(d,α)8Be in an NRA spectrum of a standard sample appeared clearly without significant background, however a broad signal from 11B(d, α)9Be appeared overlapping with a peak from 14N(d, α)12C. Therefore the 10B(d, α)8Be and 14N(d, α)12C yields were estimated, since the ratio of 11B : 10B measured by RBS was 0.83 : 17, which is well consistent with the natural isotopic ratio, 11B : 10B =0.802 : 0.192. In the case of calculating the 14N(d, α)12C yields, the signal from 11B(d, α)9Be was deconvoluted by taking into account the shape of 11B(d, α)9Be signal. The areal ratio 14N/10B was 7.73 and the error was -3.5 to +3.2%. These values will be used for determining composition of BN films. The conversion factor allows obtaining the composition of BN thin films on Si substrate. (author)

  11. Nuclear structure, nuclear reaction

    OpenAIRE

    Etchegoyen, Maria Cristina Berisso de.; Sinclair, D.; Dr. D. Sinclair

    1982-01-01

    In this thesis, particle- particle angular correlations for reactions in non-zero degree geometry and with non-zero spin nuclei are performed and found to be a valuable tool for spin determination, (d-α) angular correlations in the reaction process 14N(6Li,d)18F* (α)14N are measured for three high excited states in 18F with a 6Li beam of 36MeV. Spins and parities for two of the observed states are determined, and in agreement with theoretical predictions, these states are s...

  12. Elemental analysis by nuclear reactions in selected mineral assemblages

    International Nuclear Information System (INIS)

    The sensitivity of proton induced X-ray emission (PIXE) as a multi-elemental analytical technique for application in geochemical studies has been investigated. The contribution and unique features of PIXE as compared with other well-established analytical techniques is discussed. One such contribution is the analysis of minute (few microgram) grains of separated mineral phases, where these have a low frequency of occurence on the one hand, and / or require meticulous separation or collection on the other hand, or if variations in composition from grain to grain are meaningful. Mineral separates used in the investigation were selected specifically for their significance in geochemical studies related to the mineralisation of the Witwatersrand goldbearing system. These include gold, zircon and chromite. The success of PIXE in the analysis of gold, zircon, chromite and diamond samples is discussed. Comparisons are made of single grain and bulk (many grain) sample analyses and of PIXE measurements on such samples with instrumental activation analysis (INAA). The contribution of such analysis to the study of the evolution of the Witwatersrand system is discussed. The specific features of PIXE were exploited in a search for superheavy elements. A monazite sample from Malaysia was investigated for the occurrence of the element Z = 126. An upper limit of 110 plus minus 33 ppm for the possible concentration of this superheavy element in monazite is deduced

  13. 16O thin film reference materials for nuclear reaction analysis

    International Nuclear Information System (INIS)

    Full text: Thin film Ta2O5 samples were distributed to CRP participants for use in the round-robin exercise. This appendix describes how these samples were prepared and characterized. Preparation was made using anodic oxidation of tantalum using an electrolyte solution of 4% ammonium citrate prepared with water of natural 16O isotopic composition. A constant anodising current of 4 mA/cm2 was maintained until the desired electrolysis v voltage was reached, then stopped immediately. The areal density of 16O in these thin Ta2O5 films was determined by NRA using the method described elsewhere and comparing the data with that from a primary anodic Ta2O5 standard kindly made available to us by Dr C. Ortega of GPS, Paris. The 16O(d,p1)14N reaction at 850 keV was used with the protons detected with a 300 mm2 silicon detector located at an angle of 150 deg. A 12 μm MylarTM foil covered the detector. Detector count rates were kept sufficiently low so that deadtime corrections are negligible. There are various sources of uncertainty which when compounded, produce the final uncertainty in the 16O areal density of the thin film samples. The major sources of uncertainty are: 1. The primary reference standard is estimated to have an absolute value that is within ± 3% of the true value. 2. There is a small low energy tail on the p1 peak in the NRA spectrum, most likely due to oxygen dissolved in the bulk tantalum. The counts in this tailing are less than 2% of the gross counts recorded in the spectrum peak, and similar in magnitude from sample to sample. We assign a systematic error of 0.5% to the background correction for all samples. There is negligible change in the total sample uncertainty when this systematic error is added in quadrature to the uncertainty of the primary reference standard. 3. The reproducibility of peak areas from several measurements was better than 1%. This indicates that sample homogeneity and current integration were both sufficiently good that their

  14. Astronomy with Radioactivities: Chapter 9, Nuclear Reactions

    OpenAIRE

    Wiescher, M.; Rauscher, T.

    2010-01-01

    Nuclear reaction rates determine the abundances of isotopes in stellar burning processes. A multitude of reactions determine the reaction flow pattern which is described in terms of reaction network simulations. The reaction rates are determined by laboratory experiments supplemented by nuclear reaction and structure theory. We will discuss the experimental approach as well as the theoretical tools for obtaining the stellar reaction rates. A detailed analysis of a reaction is only possible fo...

  15. Neutrino nuclear response and photo nuclear reaction

    OpenAIRE

    Ejiri, H.; Titov, A. I.; .Boswell, M; Young, A.

    2013-01-01

    Photo nuclear reactions are shown to be used for studying neutrino/weak nuclear responses involved in astro-neutrino nuclear interactions and double beta decays. Charged current weak responses for ground and excited states are studied by using photo nuclear reactions through isobaric analog states of those states, while neutral current weak responses for excited states are studied by using photo nuclear reactions through the excited states. The weak interaction strengths are studied by measur...

  16. Nuclear reactions an introduction

    CERN Document Server

    Paetz gen. Schieck, Hans

    2014-01-01

    Nuclei and nuclear reactions offer a unique setting for investigating three (and in some cases even all four) of the fundamental forces in nature. Nuclei have been shown – mainly by performing scattering experiments with electrons, muons, and neutrinos – to be extended objects with complex internal structures: constituent quarks; gluons, whose exchange binds the quarks together; sea-quarks, the ubiquitous virtual quark-antiquark pairs and, last but not least, clouds of virtual mesons, surrounding an inner nuclear region, their exchange being the source of the nucleon-nucleon interaction.   The interplay between the (mostly attractive) hadronic nucleon-nucleon interaction and the repulsive Coulomb force is responsible for the existence of nuclei; their degree of stability, expressed in the details and limits of the chart of nuclides; their rich structure and the variety of their interactions. Despite the impressive successes of the classical nuclear models and of ab-initio approaches, there is clearly no ...

  17. Direct mechanism in solar nuclear reactions

    OpenAIRE

    Oberhummer, H; Staudt, G.

    1994-01-01

    A short overview of the direct reaction mechanism and the models used for the analysis of such processes is given. Nuclear reactions proceeding through the direct mechanism and involved in solar hydrogen burning are discussed. The significance of these nuclear reactions with respect to the solar neutrino problem is investigated.

  18. Bulk Nuclear Properties from Reactions

    OpenAIRE

    Danielewicz, P.

    2002-01-01

    Extraction of bulk nuclear properties by comparing reaction observables to results from semiclassical transport-model simulations is discussed. Specific properties include the nuclear viscosity, incompressibility and constraints on the nuclear pressure at supranormal densities.

  19. Nuclear reactions in astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Arnould, M.; Rayet, M. (Universite Libre de Bruxelles (BE))

    1990-06-01

    At all times and at all astrophysical scales, nuclear reactions have played and continue to play a key role. This concerns the energetics as well as the production of nuclides (nucleosynthesis). After a brief review of the observed composition of various objects in the universe, and especially of the solar system, the basic ingredients that are required in order to build up models for the chemical evolution of galaxies are sketched. Special attention is paid to the evaluation of the stellar yields through an overview of the important burning episodes and nucleosynthetic processes that can develop in non-exploding or exploding stars. Emphasis is put on the remaining astrophysical and nuclear physics uncertainties that hamper a clear understanding of the observed characteristics, and especially compositions, of a large variety of astrophysical objects.

  20. Determination and theoretical analysis of the differential cross sections of the 2H(d,p reaction at energies and detection angles suitable for NRA (Nuclear Reaction Analysis

    Directory of Open Access Journals (Sweden)

    Paneta V.

    2014-03-01

    Full Text Available The accurate determination of deuteron depth profile presents a strong analytical challenge for all the principal IBA (Ion Beam Analysis techniques. As far as NRA (Nuclear Reaction Analysis is concerned, the 2H(d,p reaction, seems to be a promising candidate, especially in the case of complex matrices, or for the study of deep-implanted deuteron layers. In the present work differential cross-section values for the 2H(d,p reaction have been determined at 140°, 160° and 170°, for Ed,lab=900-1600 keV, with an energy step of 50 keV, using a well-characterized, thin C:D target deposited on a polished Si wafer. The experimental results were analyzed using the R-matrix calculations code AZURE.

  1. The nuclear reaction matrix

    Energy Technology Data Exchange (ETDEWEB)

    Krenciglowa, E.M.; Kung, C.L.; Kuo, T.T.S.; Osnes, E.

    1976-09-24

    Different definitions of the reaction matrix G appropriate to the calculation of nuclear structure are reviewed and discussed. Qualitative physical arguments are presented in support of a two-step calculation of the G-matrix for finite nuclei. In the first step the high-energy excitations are included using orthogonalized plane-wave intermediate states, and in the second step the low-energy excitations are added in, using harmonic oscillator intermediate states. Accurate calculations of G-matrix elements for nuclear structure calculations in the Aapprox. =18 region are performed following this procedure and treating the Pauli exclusion operator Q/sub 2//sub p/ by the method of Tsai and Kuo. The treatment of Q/sub 2//sub p/, the effect of the intermediate-state spectrum and the energy dependence of the reaction matrix are investigated in detail. The present matrix elements are compared with various matrix elements given in the literature. In particular, close agreement is obtained with the matrix elements calculated by Kuo and Brown using approximate methods. (AIP)

  2. Determination of the helium diffusion coefficient in nuclear waste storage ceramics by a nuclear reaction analysis method

    Science.gov (United States)

    Gosset, Dominique; Trocellier, Patrick; Serruys, Yves

    2002-06-01

    Host matrices for actinide immobilisation will undergo the formation of large helium quantities due to alpha decay. Helium diffusion rate has to be known in order to predict the long-term behaviour of the material, and particularly, the influence of helium accumulation on mechanical properties. A nuclear reaction analysis method, namely the 3He(d, p) 4He reaction, has been used to analyse the evolution of 3He profiles after ion implantations at 1 and 3 MeV in two materials, monoclinic ZrO 2 (as a test material) and Ca 9Nd(PO 4) 5(SiO 4)F 1.5(OH) 0.5 britholite (envisaged for Am and Pu long-term storage). Two data processing methods are used: the classical excitation curve (proton yields versus deuteron energy) and second, the proton energy spectrum for a given deuteron energy. The characteristics of the 3He profiles (depth, width) obtained by both methods are compared to SRIM estimations. Their evolution during subsequent annealings allows an estimation of the helium diffusion rate in the britholite: D ( cm2/ s)=(2.5±1.5)×10 -4exp(-(1.07±0.03 eV)/ kT) in the temperature range 200-400 °C, in agreement with previous results on similar materials. Moreover, the shape of the proton energy spectra suggests channeling effects in britholite.

  3. Compilation and R-matrix analysis of Big Bang nuclear reaction rates

    OpenAIRE

    Descouvemont, Pierre; Adahchour, Abderrahim; Angulo, Carmen; Coc, Alain; Vangioni-Flam, Elisabeth

    2004-01-01

    We use the R-matrix theory to fit low-energy data on nuclear reactions involved in Big Bang nucleosynthesis. A special attention is paid to the rate uncertainties which are evaluated on statistical grounds. We provide S factors and reaction rates in tabular and graphical formats. Comment: 40 pages, accepted for publication at ADNDT, web site at http://pntpm3.ulb.ac.be/bigbang

  4. Transfer reactions in nuclear astrophysics

    Science.gov (United States)

    Bardayan, D. W.

    2016-08-01

    To a high degree many aspects of the large-scale behavior of objects in the Universe are governed by the underlying nuclear physics. In fact the shell structure of nuclear physics is directly imprinted into the chemical abundances of the elements. The tranquility of the night sky is a direct result of the relatively slow rate of nuclear reactions that control and determines a star’s fate. Understanding the nuclear structure and reaction rates between nuclei is vital to understanding our Universe. Nuclear-transfer reactions make accessible a wealth of knowledge from which we can extract much of the required nuclear physics information. A review of transfer reactions for nuclear astrophysics is presented with an emphasis on the experimental challenges and opportunities for future development.

  5. Preequilibrium Nuclear Reactions

    International Nuclear Information System (INIS)

    After a survey on existing experimental data on precompound reactions and a description of preequilibrium reactions, theoretical models and quantum mechanical theories of preequilibrium emission are presented. The 25 papers of this meeting are analyzed separately

  6. Nuclear Reactions from Lattice QCD

    CERN Document Server

    Briceño, Raúl A; Luu, Thomas C

    2014-01-01

    One of the overarching goals of nuclear physics is to rigorously compute properties of hadronic systems directly from the fundamental theory of strong interactions, Quantum Chromodynamics (QCD). In particular, the hope is to perform reliable calculations of nuclear reactions which will impact our understanding of environments that occur during big bang nucleosynthesis, the evolution of stars and supernovae, and within nuclear reactors and high energy/density facilities. Such calculations, being truly ab initio, would include all two-nucleon and three- nucleon (and higher) interactions in a consistent manner. Currently, lattice QCD provides the only reliable option for performing calculations of some of the low- energy hadronic observables. With the aim of bridging the gap between lattice QCD and nuclear many-body physics, the Institute for Nuclear Theory held a workshop on Nuclear Reactions from Lattice QCD on March 2013. In this review article, we report on the topics discussed in this workshop and the path ...

  7. Application of evolved gas analysis to cold-cap reactions of melter feeds for nuclear waste vitrification

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, Albert A.; Chun, Jaehun; Hrma, Pavel R.; Rodriguez, Carmen P.; Schweiger, Michael J.

    2014-04-30

    In the vitrification of nuclear wastes, the melter feed (a mixture of nuclear waste and glass-forming and modifying additives) experiences multiple gas-evolving reactions in an electrical glass-melting furnace. We employed the thermogravimetry-gas chromatography-mass spectrometry (TGA-GC-MS) combination to perform evolved gas analysis (EGA). Apart from identifying the gases evolved, we performed quantitative analysis relating the weighed sum of intensities of individual gases linearly proportional with the differential themogravimetry. The proportionality coefficients were obtained by three methods based on the stoichiometry, least squares, and calibration. The linearity was shown to be a good first-order approximation, in spite of the complicated overlapping reactions.

  8. Nuclear astrophysics from direct reactions

    OpenAIRE

    2008-01-01

    Accurate nuclear reaction rates are needed for primordial nucleosynthesis and hydrostatic burning in stars. The relevant reactions are extremely difficult to measure directly in the laboratory at the small astrophysical energies. In recent years direct reactions have been developed and applied to extract low-energy astrophysical S-factors. These methods require a combination of new experimental techniques and theoretical efforts, which are the subject of this presentation.

  9. Neutron-induced complex reaction analysis with 3D nuclear track simulation

    International Nuclear Information System (INIS)

    Complex (multiple) etched tracks are analysed through digitised images and 3D simulation by a purpose-built algorithm. From a binary track image an unfolding procedure is followed to generate a 3D track model, from which several track parameters are estimated. The method presented here allows the deposited energy, that originated from particle fragmentation or carbon spallation by means of induced tracks in commercially available PADC detectors, to be estimated. Results of evaluated nuclear tracks related to 12C (n,3αn') reaction are presented here. The detectors were exposed on the ISS in 2001

  10. Detection of submonolayer oxygen-18 on a gold surface by nuclear reaction analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wielunski, L.S.; Kenny, M.J.; Wieczorek, L. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Lindfield, NSW (Australia). Div. of Applied Physics

    1993-12-31

    A gold substrate is the preferred solid surface for formation of an organic self-assembled monolayer ( SAM ). Device fabrication process may require the gold film to be exposed to photolithographic processing and plasma treatment prior to molecular assembly. It has been observed that oxygen plasma treatment prevents the formation of SAMs; however, subsequent treatment with an argon plasma allows assembly of the organic monolayers. To understand the mechanisms involved, a plasma containing 98% {sup 18}O was used and the film surface was analysed using the {sup 18}O (p,{alpha}){sup 15}N nuclear reaction. 5 refs., 1 tab., 3 figs.

  11. Analysis of nuclear reaction products and materials; Preliminary treatment of uranium analysis

    International Nuclear Information System (INIS)

    Pre-treatment of samples is necessary to be done in order to achieve the efficient steps and accurate results of uranium analysis. The pre-treatment is particularly affected by the type of sample, the uranium concentration predicated in the sample, and the uranium analytical method which will be applied. A brief discussion about the pre-treatment of uranium analysis in the uranium ore processing and the reprocessing of spent fuel is given. (author)

  12. Lattice location of O18 in ion implanted Fe crystals by Rutherford backscattering spectrometry, channeling and nuclear reaction analysis

    Science.gov (United States)

    Vairavel, Mathayan; Sundaravel, Balakrishnan; Panigrahi, Binaykumar

    2016-09-01

    There are contradictory theoretical predictions of lattice location of oxygen interstitial atom at tetrahedral and octahedral interstices in bcc Fe. For validating these predictions, 300 keV O18 ions with fluence of 5 × 1015 ions/cm2 are implanted into bcc Fe single crystals at room temperature and annealed at 400 °C. The Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA)/channeling measurements are carried out with 850 keV protons. The lattice location of implanted O18 is analysed using the α-particles yield from O18(p,α)N15 nuclear reaction. The tilt angular scans of α-particle yield along and axial directions are performed at room temperature. Lattice location of O18 is found to be at tetrahedral interstitial site by comparing the experimental scan with simulated scans using FLUX7 software.

  13. Statistical emission in nuclear reactions

    International Nuclear Information System (INIS)

    Statistical model in nuclear reactions has been extensively developed in the past decades, mainly by V. Weisskopf. However, a clear understanding of the experimental situation regarding low- and medium- energy nuclear reaction is not yet settled. The interpretation is complicated by the fact that often the reactions proceed via other mechanisms, for instance direct effects. The purpose 'of the present paper is to show how a great number of experiments can be put in agreement with the statistical formulas, and particularly the resonance measurements for slow neutrons, the evaporation spectra from medium-energy (n, n'), (p, n) and (n, p) reactions and the (n, p) cross-sections at 14 MeV. From the set of experiments discussed it is possible to obtain a consistent table of a, the parameter of the level density formula. (author)

  14. Development of automatic nuclear emulsion plate analysis system and its application to elementary particle reactions, 2

    International Nuclear Information System (INIS)

    This system is composed of precise coordinate measuring apparatuses, a stage controller and various peripherals, employing NOVA 4/C as the host computer. The analyzed results are given as the output to a printer or an XY plotter. The data required for experiment, sent from Nagoya University and others, are received by the host computer through an acoustic coupler, and stored in floppy disks. This paper contains simple explanation on the monitor for the events which occur immediately after the on-line measurement ''MTF 1'', the XY plotter and the acoustic coupler, which hold important position in the system in spite of low cost, due to the development of useful program, as those were not described in the previous paper. The three-dimensional reconstruction of tracks and various errors, corrective processing and analytical processing after corrective processing as off-line processing are also described. In addition, the application of the system was made to the E-531 neutrino experiment in Fermi National Accelerator Laboratory, which attempted to measure the life of the charm particles generated in neutrino reaction with a composite equipment composed of nuclear plates and various counters. First, the outline of the equipment, next, the location of neutrino reaction and the surveillance of charm particle decay using MTF program as the analyzing method at the target, and thirdly, the emulsion-counter data fitting are explained, respectively. (Wakatsuki, Y.)

  15. Application of evolved gas analysis to cold-cap reactions of melter feeds for nuclear waste vitrification

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Carmen P. [Pacific Northwest National Laboratory, 902 Battelle Blvd., P.O. Box 999, MSIN K6-24, Richland, WA 99352 (United States); Chun, Jaehun, E-mail: jaehun.chun@pnnl.gov [Pacific Northwest National Laboratory, 902 Battelle Blvd., P.O. Box 999, MSIN K6-24, Richland, WA 99352 (United States); Schweiger, Michael J. [Pacific Northwest National Laboratory, 902 Battelle Blvd., P.O. Box 999, MSIN K6-24, Richland, WA 99352 (United States); Kruger, Albert A. [U.S. Department of Energy Office of River Protection, Richland, WA 99352 (United States); Hrma, Pavel [Pacific Northwest National Laboratory, 902 Battelle Blvd., P.O. Box 999, MSIN K6-24, Richland, WA 99352 (United States); Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, Pohang (Korea, Republic of)

    2014-09-20

    Highlights: • We applied the TGA-GC–MS combination to perform EGA of glass batches. • We confirmed the proportionality between mass loss rate and gas evolution intensities. • Proportionality coefficients can be obtained via single-reaction calibration. • Quantitative EGA allows mass loss rates to be matched with evolution rates for gases. • Industrial and waste glass technology can benefit from quantitative EGA. - Abstract: In the vitrification of nuclear wastes, the melter feed (a mixture of nuclear waste and glass-forming and modifying additives) experiences multiple gas-evolving reactions in an electrical glass-melting furnace. We employed the thermogravimetry-gas chromatography–mass spectrometry (TGA-GC–MS) combination to perform evolved gas analysis (EGA). Along with identifying the gases evolved, we performed quantitative analysis relating the weighted sum of intensities of individual gases in linear proportion with the differential thermogravimetry. The proportionality coefficients were obtained by three methods based on the stoichiometry, least squares, and calibration. The linearity was shown to be a good first-order approximation, in spite of the complicated overlapping reactions.

  16. Study of the deuterated titanium Ti2Hx sample by using nuclear reaction analysis and material analysis methods

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Titanium is one of the best hydrogen loading material. The pre dicted maximum loading ratio of hydrogen in titanium may reach to 2.0. In this work, a titanium layer on molybdenum substrate was deuterated with the atomic ratio X =2H/Ti>1.6. The change of the surface topography and microstructure of the sample before and after loading was observed by using Scan Electron Microscopy (SEM). The surface segregation of the samples after deuteron bombardment was also observed. A fiuctuatingly-incrcasing trend of the deuterium density in titanium target was detected in the deuteron implantation experiments. which indicated a suddenly explosion (segregation) or fast diffusion of deuterium in the titanium. Significant amount of nitrogen contamination was found in the Ti2Hx sample by nuclear reaction analysis (NRA), which indicated that the Ti2Hx structure might have the feature to trap nitrogen from air. The nitrogen contamination in Ti2Hx significantly affects the increase of the atomic ratio X =2H/Ti.

  17. Nuclear reactions from lattice QCD

    Science.gov (United States)

    Briceño, Raúl A.; Davoudi, Zohreh; Luu, Thomas C.

    2015-02-01

    One of the overarching goals of nuclear physics is to rigorously compute properties of hadronic systems directly from the fundamental theory of strong interactions, quantum chromodynamics (QCD). In particular, the hope is to perform reliable calculations of nuclear reactions which will impact our understanding of environments that occur during big bang nucleosynthesis, the evolution of stars and supernovae, and within nuclear reactors and high energy/density facilities. Such calculations, being truly ab initio, would include all two-nucleon and three-nucleon (and higher) interactions in a consistent manner. Currently, lattice quantum chromodynamics (LQCD) provides the only reliable option for performing calculations of some of the low-energy hadronic observables. With the aim of bridging the gap between LQCD and nuclear many-body physics, the Institute for Nuclear Theory held a workshop on Nuclear Reactions from LQCD on March 2013. In this review article, we report on the topics discussed in this workshop and the path planned to move forward in the upcoming years.

  18. Nuclear Reactions for Astrophysics and Other Applications

    Energy Technology Data Exchange (ETDEWEB)

    Escher, J E; Burke, J T; Dietrich, F S; Scielzo, N D; Ressler, J J

    2011-03-01

    Cross sections for compound-nuclear reactions are required for many applications. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

  19. Asian collaboration on nuclear reaction data compilation

    International Nuclear Information System (INIS)

    Nuclear reaction data are essential for research and development in nuclear engineering, radiation therapy, nuclear physics and astrophysics. Experimental data must be compiled in a database and be accessible to nuclear data users. One of the nuclear reaction databases is the EXFOR database maintained by the International Network of Nuclear Reaction Data Centres (NRDC) under the auspices of the International Atomic Energy Agency. Recently, collaboration among the Asian NRDC members is being further developed under the support of the Asia-Africa Science Platform Program of the Japan Society for the Promotion of Science. We report the activity for three years to develop the Asian collaboration on nuclear reaction data compilation. (author)

  20. Fragmentation processes in nuclear reactions

    International Nuclear Information System (INIS)

    Fragmentation processes in nuclear collisions are reviewed. The main emphasis is put on light ion breakup at nonrelativistic energies. The post- and prior-form DWBA theories are discussed. The post-form DWBA, appropriate for the ''spectator breakup'' describes elastic as well as inelastic breakup modes. This theory can also account for the stripping to unbound states. The theoretical models are compared to typical experimental results to illustrate the various possible mechanisms. It is discussed, how breakup reactions can be used to study high-lying single particle strength in the continuum; how it can yield information about momentum distributions of fragments in the nucleus. (orig.)

  1. Quantum control in nuclear reaction

    International Nuclear Information System (INIS)

    A frontier field beyond atom and molecular control will be concentrated on the controlling of nuclei. Both theoretical design and laboratory experiments extremely need to be developed with the great progress of quantum physics and laser technology. This work is to focus on the computational approach to achieve the quantum control in nuclear reaction with a stable semi-discrete numerical paradigm in high dimensions. A reasonable physical model is established by multi-Klein–Gordon Schroedinger dynamics. Demonstrative experiments would provide the confident guidance to control quantum system at nuclei scale in real laboratory. (author)

  2. Photo nuclear reactions by QMD

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, Tomoyuki; Niita, Koji; Chiba, Satoshi; Maruyama, Toshiki; Iwamoto, Akira [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-05-01

    QMD (Quantum Molecular Dynamics) was applied to photo nuclear reaction. Advantages of QMD were explained. The cross section of (Cr, pX) at 375 MeV/c was simulated. The results showed three peaks, the peak in the lowest momentum indicated contribution of statistics decay and the middle one, the largest peak, was contribution of quasi-free process (QF) which consisted of two-step process. Then, the total cross section of {pi} photoproduction for three target nuclei (C, Al and Cu) was simulated by QMD. The obtained values were larger than the experimental values, so that the present QMD calculation showed small {pi} adsorption. (S.Y.)

  3. Forging the Link between Nuclear Reactions and Nuclear Structure

    CERN Document Server

    Dickhoff, W H

    2015-01-01

    A review of the recent applications of the dispersive optical model (DOM) is presented. Emphasis is on the nonlocal implementation of the DOM that is capable of describing ground-state properties accurately when data like the nuclear charge density are available. The DOM, conceived by Claude Mahaux, provides a unified description of both elastic nucleon scattering and structure information related to single-particle properties below the Fermi energy. We have recently introduced a nonlocal dispersive optical potential for both the real and imaginary part. Nonlocal absorptive potentials yield equivalent elastic differential cross sections for ${}^{40}$Ca as compared to local ones but change the $\\ell$-dependent absorption profile suggesting important consequences for the analysis of nuclear reactions. Below the Fermi energy, nonlocality is essential for an accurate representation of particle number and the nuclear charge density. Spectral properties implied by $(e,e'p)$ and $(p,2p)$ reactions are correctly desc...

  4. Astrophysical Reaction Rates as a Challenge for Nuclear Reaction Theory

    OpenAIRE

    Rauscher, T.

    2010-01-01

    The relevant energy ranges for stellar nuclear reactions are introduced. Low-energy compound and direct reactions are discussed. Stellar modifications of the cross sections are presented. Implications for experiments are outlined.

  5. Elements from chlorine to calcium nuclear reactions

    CERN Document Server

    Kunz, Wunibald

    1968-01-01

    Nuclear Tables: Part II Nuclear Reactions, Volume 3: The Elements from Chlorine to Calcium contains tabulations of the nuclear reaction values of elements chlorine, argon, potassium, and calcium. These tabulations provide the calculated Q-values of the elements and their isotopes. This book will be of value to general chemistry researchers.

  6. Sensitivity Analysis Applied to the Validation of the 10 B Capture Reaction in Nuclear Fuel Casks

    Energy Technology Data Exchange (ETDEWEB)

    Goluoglu, S

    2004-03-18

    Boron has commonly been used in nuclear fuel casks to ensure a sufficient margin of subcriticality. The amount of boron used in most casks far exceeds the amount of boron present in any of the available benchmark experiments. Such heavy loadings of boron in the casks may result in considerable spectral differences as compared to the benchmarks, resulting in boron sensitivities that are very different from those of the benchmarks. Before the calculations to determine the nuclear safety margin for various fuel loadings are deemed acceptable, as part of the safety basis, the computer code and cross sections must be validated against experimental benchmarks that cover the area of applicability of the proposed cask design. Therefore, this study was performed to determine if these available benchmarks can be used to validate a criticality code and neutron cross sections for the fuel casks. The sensitivity/uncertainty methodology has been applied to several application cask systems with different boron areal densities. Although, the sensitivities of the nuclear fuel cask applications are not completely covered by the set of benchmarks that were used in this study with regard to the 10B capture cross section, the effect of this lack of coverage on the keff is minimal. Thus, the experimental biases are determined to be appropriate for the cask systems, and no additional bias (penalty) due to high boron loading need be imposed.

  7. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    (full text) During the last year our activities were spread over the three major domains: nuclear, atomic and material physics. The nuclear physics experimental programme covered a broad range of nuclear reactions induced by light and heavy ions. New experiments were performed at the compact C-30 cyclotron at Swierk, at University of Jyvaeskylae, GSI Darmstadt, LN Saturne. Prospects for future experiments on nucleon structure at Forschungszentrum Juelich were open. The collaboration with INR Kiev was tightened and work was done in order to prepare experiments at the C-200 heavy ion cyclotron in Warsaw. An effort to install the ion guide isotope separator on line (IGISOL) at the C-200 cyclotron has also to be mentioned A half a year stay of Dr. Nicholas Keeley in the Department, who received The Royal Society/Polish Academy of Science grant, resulted in many interesting results on breakup of light nuclei. Details can be found in the short abstracts presented in this report. As far as atomic physics is concerned, the activity of a group lead by Prof. Marian Jaskola yielded various new results. The experiments were performed at the University of Erlangen, in close collaboration with the Pedagogical University in Kielce and the University of Basel. Fast neutrons generated in the 3H(d,n)4He reaction induced by the 2 MeV deuteron beam from the Van der Graaff accelerator at the Department were used to calibrate solid state-nuclear-track detectors. This was a very good year for material physics research: Jan Kaczanowski and Slawomir Kwiatkawski received Ph.D. degrees based on dissertation research performed in the material physics research programme, while Pawel Kolodziej completed his MSc. thesis in collaboration with the Institute of Electronic Materials Technology in Warsaw, Research Center Karlsruhe, University of Jena and CSNSM Orsay many results were obtained. Lech Nowicki and Prof. Andrzej Turos were awarded by the Director of the IPJ prizes for their scientific

  8. Hydrogen incorporation and radiation induced dynamics in metal-oxide-silicon structures. A study using nuclear reaction analysis

    International Nuclear Information System (INIS)

    Resonant nuclear reaction analysis, using the 1H(15N, αγ)12C reaction at 6.4 MeV, has been successfully applied to the investigation of hydrogen incorporation and radiation induced migration in metal-oxide-silicon structures. A preliminary study of the influence of processing parameters on the H content of thermal oxides, with and without gate material present, has been performed. It is found that the dominant source of hydrogen in Al gate devices and dry oxides is often contamination, likely in the form of adsorbed water vapor, formed upon exposure to room air after removal from the oxidation furnace. Concentrations of hydrogen in the bulk oxide as high as 3 1020 cm-3 (Al gate), and as low as 1 1018 cm-3 (poly Si-gate) have been observed. Hydrogen accumulation at the Si-SiO2 interface has been reproducibly demonstrated for as-oxidized samples, as well as for oxides exposed to H2 containing atmospheres during subsequent thermal processing. The migration of hydrogen, from the bulk oxide to the silicon-oxide interface during NRA, has been observed and intensively investigated. A direct correlation between the hydrogen content of the bulk oxide and the radiation generated oxide charges and interface states is presented. These data provide strong support for the important role of hydrogen in determining the radiation sensitivity of electronic devices. (orig.)

  9. [Electromagnetic studies of nuclear structure and reactions

    International Nuclear Information System (INIS)

    The experimental goals are focused on developing an understanding of strong interactions and the structure of hadronic systems by determination of the electromagnetic response; these goals will be accomplished through coincidence detection of final states. Nuclear modeling objectives are to organize and interpret the data through a consistent description of a broad spectrum of reaction observables; calculations are performed in a nonrelativistic diagrammatic framework as well as a relativistic QHD approach. Work is described according to the following arrangement: direct knockout reactions (completion of 16O(e,e'p), 12C(e,e'pp) progress, large acceptance detector physics simulations), giant resonance studies (intermediate-energy experiments with solid-state detectors, the third response function in 12C(e,e'p0) and 16O(e,e'p0), comparison of the 12C(e, e'p0) and 16O(e,e'p3) reactions, quadrupole strength in the 16O(e,e'α0) reaction, quadrupole strength in the 12C(e,e'α) reaction, analysis of the 12C(e,e'p1) and 16O(e,e'p3) angular distributions, analysis of the 40Ca(e,e'x) reaction at low q, analysis of the higher-q 12C(e,e'x) data from Bates), models of nuclear structure (experimental work, Hartree-Fock calculations, phonon excitations in spherical nuclei, shell model calculations, variational methods for relativistic fields), and instrumentation development efforts (developments at CEBAF, CLAS contracts, BLAST developments)

  10. Modelling of the spallation reaction: analysis and testing of nuclear models

    International Nuclear Information System (INIS)

    The spallation reaction is considered as a 2-step process. First a very quick stage (10-22, 10-29 s) which corresponds to the individual interaction between the incident projectile and nucleons, this interaction is followed by a series of nucleon-nucleon collisions (intranuclear cascade) during which fast particles are emitted, the nucleus is left in a strongly excited level. Secondly a slower stage (10-18, 10-19 s) during which the nucleus is expected to de-excite completely. This de-excitation is performed by evaporation of light particles (n, p, d, t, 3He, 4He) or/and fission or/and fragmentation. The HETC code has been designed to simulate spallation reactions, this simulation is based on the 2-steps process and on several models of intranuclear cascades (Bertini model, Cugnon model, Helder Duarte model), the evaporation model relies on the statistical theory of Weiskopf-Ewing. The purpose of this work is to evaluate the ability of the HETC code to predict experimental results. A methodology about the comparison of relevant experimental data with results of calculation is presented and a preliminary estimation of the systematic error of the HETC code is proposed. The main problem of cascade models originates in the difficulty of simulating inelastic nucleon-nucleon collisions, the emission of pions is over-estimated and corresponding differential spectra are badly reproduced. The inaccuracy of cascade models has a great impact to determine the excited level of the nucleus at the end of the first step and indirectly on the distribution of final residual nuclei. The test of the evaporation model has shown that the emission of high energy light particles is under-estimated. (A.C.)

  11. Department of Nuclear Reaction - Overview

    International Nuclear Information System (INIS)

    . The same effects can be crucial for the extraction of polarized quark distributions (spin puzzle) from semi-inclusive production of pions in DIS. It was carefully studied how production of dijets in real and virtual photoproduction provides new information on unintegrated gluon distribution. We have completed the construction of the Forward Wall detector for the CHICSi experiment at the Celsius synchrotron. First tests with 20Ne beam at 200 MeV/nucleon on 40Ar and 14N targets were performed. New results on the formation of dtμ, Muonic Molecule in Solid Hydrogen Target were obtained. First tests of the low energy spallation apparatus for measuring low energy spallation products emitted in proton induced reactions were performed using accelerator facilities at Catania (Italy). Further studies of statistical aspects of nuclear coupling to continuum were pursued. It was found that in the region of higher density of states the coupling to continuum is consistent with the statistical model. One Ph.D. thesis was completed under the supervision of Prof. Drozdz. The newly born doctor J. Kwapien was awarded The Henryk Niewodniczanski prize for his scientific achievement in studying the brain function. (author)

  12. Forging the link between nuclear reactions and nuclear structure

    CERN Document Server

    Mahzoon, M H; Dickhoff, W H; Dussan, H; Waldecker, S J

    2013-01-01

    A comprehensive description of all single-particle properties associated with the nucleus ${}^{40}$Ca is generated by employing a nonlocal dispersive optical potential capable of simultaneously reproducing all relevant data above and below the Fermi energy. The introduction of nonlocality in the absorptive potentials yields equivalent elastic differential cross sections as compared to local versions but changes the absorption profile as a function of angular momentum suggesting important consequences for the analysis of nuclear reactions. Below the Fermi energy, nonlocality is essential to allow for an accurate representation of particle number and the nuclear charge density. Spectral properties implied by $(e,e'p)$ and $(p,2p)$ reactions are correctly incorporated, including the energy distribution of about 10% high-momentum nucleons, as experimentally determined by data from Jefferson Lab. These high-momentum nucleons provide a substantial contribution to the energy of the ground state, indicating a residua...

  13. Student Reactions to Nuclear Education.

    Science.gov (United States)

    Christie, Daniel J.; Nelson, Linden

    1988-01-01

    Reports on a study that focused on the psychological impact of nuclear education curriculum on middle school students. Concluded that instruction about nuclear issues rarely increases students' fear or worry about nuclear war. (RT)

  14. Theoretical studies in nuclear reactions and nuclear structure

    International Nuclear Information System (INIS)

    This report discusses topics in the following areas: Hadronic structure; hadrons in nuclei; hot hadronic matter; relativistic nuclear physics and NN interaction; leptonic emissions from high-Z heavy ion collisions; theoretical studies of heavy ion dynamics; nuclear pre-equilibrium reactions; classical chaotic dynamics and nuclear structure; and, theory of nuclear fission

  15. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Full text: It is surprising how so few under-paid scientists could do so much. During 2004 the number of papers published or being in press exceeded fifty, making almost three papers per person employed in our department. Furthermore, among these papers one was published in Nature, the World's highest-ranked scientific journal. This is a result that will be difficult to beat. It is my pleasure to mention that one of our PhD students, Mr Sergiy Mezhevych, won a prestigious Heavy Ion Laboratory Prize founded by Prof. Inamura, for his experimental work using a beam from the Warsaw Cyclotron. Thanks to the effort of our colleagues the Hermes Collaboration Meeting organized by IPJ in Kazimierz Dolny (June 25 - July 1) turned out a success. The following short reports cover the three major domains of our scientific activities: nuclear, materials and atomic physics. -Nuclear physics - The structure of light nuclei, including exotic radioactive isotopes, was investigated both experimentally and theoretically. Some experimental studies were performed at the Heavy Ion Laboratory of Warsaw University in collaboration with scientists from the Institute of Nuclear Research in Kiev, Ukraine. The two reports present interesting results for the rare carbon isotope, 14C. In the framework of Feshbach, Kerman and Koonin theory the multistep emission of one particle as well as more complicated direct processes were studied. It was found that these more complex processes play an important role in proton induced reactions. Experimental data from projectile-multifragmentation experiments with stable and radioactive beams were analysed. Some preliminary results are presented. Using a proton beam provided by the C-30 compact cyclotron at Swierk, detectors consisting of a PWO scintillator coupled to avalanche photodiodes were tested. The aim of these tests was to find the best detectors for the large electromagnetic calorimeter which will be used in future PANDA Collaboration experiments

  16. Study of the diffusion behaviour of aluminium in silicon up to 900°C by nuclear reaction analysis

    Science.gov (United States)

    Hauser, T.; Friedland, E.; Naidoo, S. R.

    2000-03-01

    Diffusion behaviour of aluminium in silicon at temperatures up to T=900°C was investigated by nuclear reaction analysis (NRA). Previously published results predict diffusion coefficients ranging from 3×10 -15 to 1.3×10 -13 cm 2 s -1 at T=900°C. In a first series aluminium films were vapour deposited onto Si substrates, followed by isochronal annealing. The diffusion coefficient was found to be less than 10 -15 cm 2 s -1 at 900°C. In a second series Si and Si samples were implanted at room temperature and at 250°C with a fluence of 5×10 16 Al + cm -2. For the samples implanted at 250°C and subsequently annealed at 900°C, the diffusion coefficient was again found to be less than 10 -15 cm 2 s -1, while diffusion coefficients of the order of 10 -13 cm 2 s -1 were observed for the room-temperature implanted samples. Channeling analyses revealed extensive radiation damage in the latter samples, which was still present after annealing for 1 h at 900°C. In contrast to this, the samples implanted at 250°C were virtually defect-free. From this it is concluded that the high values observed for the room-temperature implants are due to defect-assisted diffusion.

  17. Study of non-1/ ν reaction nuclides using k0 - Neutron Activation Analysis at the Malaysian Nuclear Agency Research Reactor

    International Nuclear Information System (INIS)

    The modified spectral index r(α); the Westcott gLu(Tn) factor and absolute neutron temperature Tn were determined for the handling of non-1/ ν (n, γ) reaction based on the Westcott formalism using k0-neutron activation analysis (k0-NAA) method at the Malaysian Nuclear Agency (MNA) research reactor. The r(α) was determined by the bare bi-isotopic monitor method using measurement of radionuclides of 97Zr and 95Zr. The 176Lu as non-1/ ν and 197Au as 1/ ν monitors were utilized for determination of gLu(Tn). The r(α) and gLu(Tn) values ranged from 0.0715 to 0.1417 with a RSD of 15.24 % and from 1.7832 to 2.0149 with a RSD of 3.58 %, respectively. The accuracy of the method was evaluated based on the calculated absolute neutron temperature (Tn) value. The calculated average value of Tn was 40.56 ± 9.32 degree Celsius while the value reported by MNA was 40 degree Celsius, which represents an acceptable level of consistency. (author)

  18. Forging the link between nuclear reactions and nuclear structure

    Science.gov (United States)

    Dickhoff, W. H.

    2016-06-01

    A review of the recent applications of the dispersive optical model (DOM) is presented. Emphasis is on the nonlocal implementation of the DOM that is capable of describing ground-state properties accurately when data like the nuclear charge density are available. The present understanding of the role of short- and long-range physics in determining proton properties near the Fermi energy for stable closed-shell nuclei has relied mostly on data from the (e, e' p) reaction. Hadronic tools to extract such spectroscopic information have been hampered by the lack of a consistent reaction description that provides unambiguous and undisputed results. The DOM, conceived by Claude Mahaux, provides a unified description of both elastic nucleon scattering and structure information related to single-particle properties below the Fermi energy. We have recently introduced a nonlocal dispersive optical potential for both the real and imaginary part. Nonlocal absorptive potentials yield equivalent elastic differential cross sections for 40Ca as compared to local ones but change the l-dependent absorption profile suggesting important consequences for the analysis of nuclear reactions. Below the Fermi energy, nonlocality is essential for an accurate representation of particle number and the nuclear charge density. Spectral properties implied by (e, e' p) and (p, 2p) reactions are correctly described, including the energy distribution of about 10% high-momentum protons obtained at Jefferson Lab. The nonlocal DOM allows a complete description of experimental data both above (up to 200 MeV) and below the Fermi energy in 40Ca. It is further demonstrated that elastic nucleon-nucleus scattering data constrain the spectral strength in the continuum of orbits that are nominally bound in the independent-particle model. Extension of this analysis to 48Ca allows a prediction of the neutron skin of this nucleus that is larger than most predictions made so far.

  19. Nuclear effects in neutrino induced reactions

    CERN Document Server

    Vacas, M J Vicente; Geng, L S; Nieves, J; Valverde, M; Hirenzaki, S

    2008-01-01

    We discuss the relevance of nuclear medium effects in the analysis of some low and medium energy neutrino reactions of current interest. In particular, we study the Quasi-Elastic (QE) process, where RPA correlations and Final State Interactions (FSI) are shown to play a crucial role. We have also investigated the neutrino induced coherent pion production. We find a strong reduction of the cross section due to the distortion of the pion wave function and the modification of the production mechanisms in the nucleus. The sensitivity of the results to the axial $N\\Delta$ coupling $C_5^A(0)$ has been also investigated.

  20. Heavy ion induced nuclear reactions: cross-section measurements and its applicability in thin layer activation analysis

    International Nuclear Information System (INIS)

    Aiming to investigate the surface wear study, we have measured the cross-sections of various reactions from the 16O induced reactions on isotopically pure targets 130Te, 159Tb, 169Tm and 181Ta in order to apply HI activation in the TLA technique. The experimental cross-sections of nuclear reactions leading to residues are very important to be known for the yields of the products before its application in a particular material. The experiments have been performed, employing energetic 16O7+ beam, from the 15UD-Pelletron accelerator, of the IUAC, New Delhi, India. For the measurement of cross-sections, targets of 130Te, 159Tb, 169Tm and 181Ta of thicknesses ≈1.5-2.0 mg/cm2 have been used

  1. Nuclear reaction rates and the primordial nucleosynthesis

    OpenAIRE

    Mishra, Abhishek; Basu, D. N.

    2011-01-01

    The theoretical predictions of the primordial abundances of elements in the big-bang nucleosynthesis (BBN) are dominated by uncertainties in the input nuclear reaction rates. We investigate the effect of modifying these reaction rates on light element abundance yields in BBN by replacing the thirty-five reaction rates out of the existing eighty-eight. We have studied these yields as functions of evolution time or temperature. We find that using these new reaction rates results in only a littl...

  2. Towards Quantum Transport for Nuclear Reactions

    OpenAIRE

    Danielewicz, Pawel; Rios, Arnau; Barker, Brent

    2009-01-01

    Nonequilibrium Green's functions represent a promising tool for describing central nuclear reactions. Even at the single-particle level, though, the Green's functions contain more information that computers may handle in the foreseeable future. In this study, we investigate whether all the information contained in the Green's functions is necessarily relevant when describing the time evolution of nuclear reactions. For this, we carry out mean-field calculations of slab collisions in one dimen...

  3. Nuclear reactions video (knowledge base on low energy nuclear physics)

    International Nuclear Information System (INIS)

    The NRV (nuclear reactions video) is an open and permanently extended global system of management and graphical representation of nuclear data and video-graphic computer simulation of low energy nuclear dynamics. It consists of a complete and renewed nuclear database and well known theoretical models of low energy nuclear reactions altogether forming the 'low energy nuclear knowledge base'. The NRV solves two main problems: 1) fast and visualized obtaining and processing experimental data on nuclear structure and nuclear reactions; 2) possibility for any inexperienced user to analyze experimental data within reliable commonly used models of nuclear dynamics. The system is based on the realization of the following principal things: the net and code compatibility with the main existing nuclear databases; maximal simplicity in handling: extended menu, friendly graphical interface, hypertext description of the models, and so on; maximal visualization of input data, dynamics of studied processes and final results by means of real three-dimensional images, plots, tables and formulas and a three-dimensional animation. All the codes are composed as the real Windows applications and work under Windows 95/NT

  4. Hokkaido University Nuclear Reaction Data Centre (JCPRG)

    International Nuclear Information System (INIS)

    A research project to compile Charged-Particle Nuclear Reaction Data was initiated in 1974, which was approved by the Theoretical Nuclear Physics Society and the Experimental Nuclear Physics Society in Japan. When this project started, a mutual agreement with the JAERI Nuclear Data Centre was concluded; this Study Group would be responsible for Charged- Particle Nuclear Reaction Data while JAERI would be in charge of Nuclear Neutron Data. The original database (NRDF, Nuclear Reaction Data File) was devised by the Study Group under the sponsorship of the Japanese Ministry of Education, Science and Culture through the Grant-in-Aid for Scientific Research. With data storage and retrieval functions added to the original NRDF system, the project developed from the stage of research and development to the practical working stage of data compilation and data dissemination in 1987. Subsequently, the Study Group was reorganized to become the Japan Charged-Particle Nuclear Reaction Data Group (JCPRG) in NRDC, and was assigned an annual budget through the Nuclear Physics Laboratory, Department of Physics, Hokkaido University by the Ministry of Education, Science and Culture. This regular JCPRG budget ended in 2001, and was replaced by a yearly competitive process. The primary aims of JCPRG are to construct and provide an academic-oriented database according to an original and unique format by compiling and storing all charged-particle nuclear reaction data produced with Japanese accelerators. JCPRG is also responsible for transforming NRDF to EXFOR format, and sending these files to IAEA-NDS. On April 1, 2007, the Japan Charged-Particle Nuclear Reaction Data Group (JCPRG) was reorganized to the Hokkaido University Nuclear Reaction Data Centre (JCPRG) as a measure taken in the Faculty of Science, Hokkaido University. At the same time, the graduate school collaboration field ''Nuclear Data'' science with Japan Atomic Energy Agency (JAEA) was established in the Department of

  5. A comprehensive survey of nuclear reactions; Panorama des reactions nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Cugnon, J. [Liege Univ., IFPA, AGO Dept. (Belgium)

    2007-07-01

    The various mechanisms of nuclear reactions are surveyed and classified in different regimes, based on the notions of coherent mechanisms and hard versus soft processes. The emphasis is put on the concepts at the basis of the understanding of these regimes and on the elements of nuclear structure which are involved in these different regimes, as well as the on the possibility of extracting this information. Due to lack of space and for pedagogical reasons, the discussion is limited to nucleon-induced and light-ion-induced reactions. However, a few remarks are given concerning some specific probes, such as weakly bound projectiles or neutron-rich nuclei. (author)

  6. Nuclear phenomena in low-energy nuclear reaction research.

    Science.gov (United States)

    Krivit, Steven B

    2013-09-01

    This is a comment on Storms E (2010) Status of Cold Fusion, Naturwissenschaften 97:861-881. This comment provides the following remarks to other nuclear phenomena observed in low-energy nuclear reactions aside from helium-4 make significant contributions to the overall energy balance; and normal hydrogen, not just heavy hydrogen, produces excess heat.

  7. Nuclear excitations and reaction mechanisms

    International Nuclear Information System (INIS)

    This Progress Report describes the work of the Brown University Nuclear Theory Group for the period 1 August 1988--31 July 1989 under Grant FG02-87ER40334. Completed and on-going research includes various theoretical and numerical studies on: virtual photons, electric polarizability, the Cabibo-Radicati sum rule, photon scattering, electron scattering, electron scattering sum rules, muon catalyzed fusion, few body collisions and breakup phenomena. Since it accompanies the three-year Renewal Proposal of the Group, it goes into more detail than our typical one-year reports

  8. Kinetics of Cold-Cap Reactions for Vitrification of Nuclear Waste Glass Based on Simultaneous Differential Scanning Calorimetry - Thermogravimetry (DSC-TGA) and Evolved Gas Analysis (EGA)

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Carmen P.; Pierce, David A.; Schweiger, Michael J.; Kruger, Albert A.; Chun, Jaehun; Hrma, Pavel R.

    2013-12-03

    For vitrifying nuclear waste glass, the feed, a mixture of waste with glass-forming and modifying additives, is charged onto the cold cap that covers 90-100% of the melt surface. The cold cap consists of a layer of reacting molten glass floating on the surface of the melt in an all-electric, continuous glass melter. As the feed moves through the cold cap, it undergoes chemical reactions and phase transitions through which it is converted to molten glass that moves from the cold cap into the melt pool. The process involves a series of reactions that generate multiple gases and subsequent mass loss and foaming significantly influence the mass and heat transfers. The rate of glass melting, which is greatly influenced by mass and heat transfers, affects the vitrification process and the efficiency of the immobilization of nuclear waste. We studied the cold-cap reactions of a representative waste glass feed using both the simultaneous differential scanning calorimetry thermogravimetry (DSC-TGA) and the thermogravimetry coupled with gas chromatography-mass spectrometer (TGA-GC-MS) as complementary tools to perform evolved gas analysis (EGA). Analyses from DSC-TGA and EGA on the cold-cap reactions provide a key element for the development of an advanced cold-cap model. It also helps to formulate melter feeds for higher production rate.

  9. Nuclear structure and pion reactions

    International Nuclear Information System (INIS)

    Shell model analyses of inelastic pion and electron scattering are used to derive many body wave functions suitable for DCX studies of masses 14 and 18. These calculations show clear evidence for the need to include core-excitations in the wave functions of the ground and excited states of these nuclei. The appropriate enhancement and quenching of the isoscalar and isovector one-body density matrix elements are deduced, and their possible effects on DCX cross-sections discussed. Effective (q-dependent) transitions, obtained from microscopic core-polarization calculations, are found to give an excellent description of the pion angular distributions and π+/π- ratios in this mass region, justifying the use of effective charges in shell model studies of pion reactions. 13 refs., 12 figs

  10. A comprehensive survey of nuclear reactions

    International Nuclear Information System (INIS)

    The various mechanisms of nuclear reactions are surveyed and classified in different regimes, based on the notions of coherent mechanisms and hard versus soft processes. The emphasis is put on the concepts at the basis of the understanding of these regimes and on the elements of nuclear structure which are involved in these different regimes, as well as the on the possibility of extracting this information. Due to lack of space and for pedagogical reasons, the discussion is limited to nucleon-induced and light-ion-induced reactions. However, a few remarks are given concerning some specific probes, such as weakly bound projectiles or neutron-rich nuclei. (author)

  11. Quantitative Analysis of Plutonium Content in Particles Collected from a Certified Reference Material by Total Nuclear Reaction Energy (Q Value) Spectroscopy

    Science.gov (United States)

    Croce, M. P.; Hoover, A. S.; Rabin, M. W.; Bond, E. M.; Wolfsberg, L. E.; Schmidt, D. R.; Ullom, J. N.

    2016-08-01

    Microcalorimeters with embedded radioisotopes are an emerging category of sensor with advantages over existing methods for isotopic analysis of trace-level nuclear materials. For each nuclear decay, the energy of all decay products captured by the absorber (alpha particles, gamma rays, X-rays, electrons, daughter nuclei, etc.) is measured in one pulse. For alpha-decaying isotopes, this gives a measurement of the total nuclear reaction energy (Q value) and the spectra consist of well-separated, narrow peaks. We have demonstrated a simple mechanical alloying process to create an absorber structure consisting of a gold matrix with small inclusions of a radioactive sample. This absorber structure provides an optimized energy thermalization environment, resulting in high-resolution spectra with minimal tailing. We have applied this process to the analysis of particles collected from the surface of a plutonium metal certified reference material (CRM-126A from New Brunswick Laboratory) and demonstrated isotopic analysis by microcalorimeter Q value spectroscopy. Energy resolution from the Gaussian component of a Bortels function fit was 1.3 keV FWHM at 5244 keV. The collected particles were integrated directly into the detector absorber without any chemical processing. The ^{238}Pu/^{239}Pu and ^{240}Pu/^{239}Pu mass ratios were measured and the results confirmed against the certificate of analysis for the reference material. We also demonstrated inter-element analysis capability by measuring the ^{241}Am/^{239}Pu mass ratio.

  12. Quantitative Analysis of Plutonium Content in Particles Collected from a Certified Reference Material by Total Nuclear Reaction Energy (Q Value) Spectroscopy

    Science.gov (United States)

    Croce, M. P.; Hoover, A. S.; Rabin, M. W.; Bond, E. M.; Wolfsberg, L. E.; Schmidt, D. R.; Ullom, J. N.

    2016-03-01

    Microcalorimeters with embedded radioisotopes are an emerging category of sensor with advantages over existing methods for isotopic analysis of trace-level nuclear materials. For each nuclear decay, the energy of all decay products captured by the absorber (alpha particles, gamma rays, X-rays, electrons, daughter nuclei, etc.) is measured in one pulse. For alpha-decaying isotopes, this gives a measurement of the total nuclear reaction energy (Q value) and the spectra consist of well-separated, narrow peaks. We have demonstrated a simple mechanical alloying process to create an absorber structure consisting of a gold matrix with small inclusions of a radioactive sample. This absorber structure provides an optimized energy thermalization environment, resulting in high-resolution spectra with minimal tailing. We have applied this process to the analysis of particles collected from the surface of a plutonium metal certified reference material (CRM-126A from New Brunswick Laboratory) and demonstrated isotopic analysis by microcalorimeter Q value spectroscopy. Energy resolution from the Gaussian component of a Bortels function fit was 1.3 keV FWHM at 5244 keV. The collected particles were integrated directly into the detector absorber without any chemical processing. The ^{238} Pu/^{239} Pu and ^{240} Pu/^{239} Pu mass ratios were measured and the results confirmed against the certificate of analysis for the reference material. We also demonstrated inter-element analysis capability by measuring the ^{241} Am/^{239} Pu mass ratio.

  13. Experimental (Network) and Evaluated Nuclear Reaction Data at NDS

    International Nuclear Information System (INIS)

    Dr Simakov of Nuclear Data Services Unit in the Nuclear Data Section (NDS) gave a brief overview of the data compilation and evaluation activities in the nuclear data community: experimental nuclear reaction data (EXFOR, http://www-nds.iaea.org/exfor/) and evaluated nuclear reaction data (ENDF, http://www-nds.iaea.org/endf). The International Network of Nuclear Reaction Data Centres (NRDC) coordinated by NDS includes 14 Centres in 8 Countries (China, Hungary, India, Japan, Korea, Russian, Ukraine, USA) and 2 International Organizations (NEA, IAEA). It had the first meeting of four core centres (Brookhaven, Saclay, Obninsk, Vienna) in 1966 and the EXFOR was adopted as an official data exchange format. In 2000, IAEA implemented the EXFOR database as a relational multiform database and the EXFOR is a trusted, increasing and living database with 19100 experimental works (as of September 2011) and 141600 data tables. The EXFOR provides a compilation control system for selection of articles and compilation of data and the NRDC home page provides manuals, documents and codes. The nuclear data can be retrieved by the web-retrieval system or distributed on a DVD on request. The EXFOR data play a critical role in the development of evaluated nuclear reaction data. There are several major general purpose libraries: ENDF (US), CENDL (China), JEFF (EU), JENDL (Japan) and RUSFOND (Russia). In addition, there are special libraries for particular applications: EAF (European Activation File), FENDL (Fusion Evaluated Nuclear Data Library for ITER neutronics), IBANDL (Ion Beam Analysis Nuclear Data Library for surface analysis of solids), IRDF, DXS (Dosimetry, radiation damage and gas production data) and Medical portal. Dr V. Zerkin of NDS demonstrated the data retrieval from the EXFOR database and the ENDF library.

  14. Statistical theory of neutron-nuclear reactions

    International Nuclear Information System (INIS)

    In addition to the topics dealt with by the author in his lectures at the Joint IAEA/ICTP Course held at Trieste in 1978, recent developments in the statistical theory of multistep reactions are reviewed as well as the transport theory and intranuclear cascade approaches to the description of nuclear multi-step processes. (author)

  15. An updated nuclear reaction network for BBN

    OpenAIRE

    Serpico, P. D.

    2004-01-01

    The key Standard-Physics inputs of the Big Bang Nucleosynthesis (BBN) are the light nuclei reaction rates. Both the network and the nuclear rates have been recently reanalyzed and updated, and cosmological and New-Physics constraints (taking into account the WMAP Cosmic Microwave Background anisotropies measurement) obtained with a new code are presented.

  16. A Nuclear Reactions Primer with Computers.

    Science.gov (United States)

    Calle, Carlos I.; Roach, Jennifer A.

    1987-01-01

    Described is a microcomputer software program NUCLEAR REACTIONS designed for college level students and in use at Sweet Briar College (Sweet Briar, VA). The program is written in Microsoft Basic Version 2.1 for the Apple Macintosh Microcomputer. It introduces two conservation principles: (1) conservation of charge; and (2) conservation of nucleon…

  17. R-Matrix Analysis of Structures in Economic Indices: from Nuclear Reactions to High-Frequency Trading

    Science.gov (United States)

    Firk, Frank W. K.

    2014-03-01

    It is shown that the R-matrix theory of nuclear reactions is a viable mathematical theory for the description of the fine, intermediate and gross structure observed in the time-dependence of economic indices in general, and the daily Dow Jones Industrial Average in particular. A Lorentzian approximation to R-matrix theory is used to analyze the complex structures observed in the Dow Jones Industrial Average on a typical trading day. Resonant structures in excited nuclei are characterized by the values of their fundamental strength function, (average total width of the states)/(average spacing between adjacent states). Here, values of the ratios (average lifetime of individual states of a given component of the daily Dow Jones Industrial Average)/(average interval between the adjacent states) are determined. The ratios for the observed fine and intermediate structure of the index are found to be essentially constant throughout the trading day. These quantitative findings are characteristic of the highly statistical nature of many-body, strongly interacting systems, typified by daily trading. It is therefore proposed that the values of these ratios, determined in the first hour-or-so of trading, be used to provide valuable information concerning the likely performance of the fine and intermediate components of the index for the remainder of the trading day.

  18. Nuclear Reactions Used For Superheavy Element Research

    Science.gov (United States)

    Stoyer, Mark A.

    2008-04-01

    Some of the most fascinating questions about the limits of nuclear stability are confronted in the heaviest nuclei. How many more new elements can be synthesized? What are the nuclear and chemical properties of these exotic nuclei? Does the "Island of Stability" exist and can we ever explore the isotopes inhabiting that nuclear region? This paper will focus on the current experimental research on the synthesis and characterization of superheavy nuclei with Z>112 from the Dubna/Livermore collaboration. Reactions using 48Ca projectiles from the U400 cyclotron and actinide targets (233,238U, 237Np, 242,244Pu, 243Am, 245,248Cm, 249Cf) have been investigated using the Dubna Gas Filled Recoil Separator in Dubna over the last 8 years. In addition, several experiments have been performed to investigate the chemical properties of some of the observed longer-lived isotopes produced in these reactions. Some comments will be made on nuclear reactions used for the production of the heaviest elements. A summary of the current status of the upper end of the chart of nuclides will be presented.

  19. Towards Quantum Transport for Central Nuclear Reactions

    CERN Document Server

    Danielewicz, Pawel; Barker, Brent

    2016-01-01

    Nonequilibrium Green's functions represent a promising tool for describing central nuclear reactions. Even at the single-particle level, though, the Green's functions contain more information that computers may handle in the foreseeable future. In this study, we explore slab collisions in one dimension, first in the mean field approximation and demonstrate that only function elements close to the diagonal in arguments are relevant, in practice, for the reaction calculations. This bodes well for the application of the Green's functions to the reactions. Moreover we demonstrate that an initial state for a reaction calculation may be generated through adiabatic transformation of interactions. Finally, we report on our progress in incorporating correlations into the dynamic calculations.

  20. Aerosol simulation including chemical and nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Marwil, E.S.; Lemmon, E.C.

    1985-01-01

    The numerical simulation of aerosol transport, including the effects of chemical and nuclear reactions presents a challenging dynamic accounting problem. Particles of different sizes agglomerate and settle out due to various mechanisms, such as diffusion, diffusiophoresis, thermophoresis, gravitational settling, turbulent acceleration, and centrifugal acceleration. Particles also change size, due to the condensation and evaporation of materials on the particle. Heterogeneous chemical reactions occur at the interface between a particle and the suspending medium, or a surface and the gas in the aerosol. Homogeneous chemical reactions occur within the aersol suspending medium, within a particle, and on a surface. These reactions may include a phase change. Nuclear reactions occur in all locations. These spontaneous transmutations from one element form to another occur at greatly varying rates and may result in phase or chemical changes which complicate the accounting process. This paper presents an approach for inclusion of these effects on the transport of aerosols. The accounting system is very complex and results in a large set of stiff ordinary differential equations (ODEs). The techniques for numerical solution of these ODEs require special attention to achieve their solution in an efficient and affordable manner. 4 refs.

  1. Nuclear proliferation in the Near East. What is the reaction of the regional neighbors on Iran's nuclear program? An analysis based on the proliferation debate; Nukleare Proliferation im Nahen Osten. Wie reagieren die regionalen Nachbarn auf Irans Nuklearprogramm? Eine Analyse anhand der Proliferationsdebatte

    Energy Technology Data Exchange (ETDEWEB)

    Erny, Matthias [Zuericher Hochschule fuer Angewandte Wissenschaften (ZHAW), Winterthur (Switzerland)

    2012-07-01

    The booklet on the reactions of the neighbor states on Iran's nuclear program covers the following topics: Iran's position in the Near East: historical aspects, Iran's nuclear program. The nuclear proliferation and the theory debate: the role of nuclear weapons in the international policy, proliferation optimism, proliferation pessimism. Analysis of the players and theory criticism: nuclear states (Israel, Pakistan), emerging nuclear states (Saudi Arab, Egypt, Turkey, Syria), states without nuclear weapons (Iraq, Jordan, GCC states); analysis, theory criticism.

  2. $^{12}$C nuclear reaction measurements for hadrontherapy.

    CERN Document Server

    B. Braunn, B; G. Ban, G; J.Colin, J; D. Cussol, D; J.M. Fontbonne, J M; F.R.. Lecolley, F R; C. Pautard, C; Haas, F; Lebhertz, D; Rousseau, M; Stuttge, L; Chevallier, M; Dauvergne, D; Le Foulher, F; Ray, C; Testa, E; Testa, M; Salsac, M D

    2010-01-01

    Hadrontherapy treatments require a very high precision on the dose deposition ( 2.5% and 1-2mm) in order to keep the benefits of the precise ions’ ballistic. The largest uncertainty on the physical dose deposition is due to ion fragmentation. Up to now, the simulation codes are not able to reproduce the fragmentation process with the required precision. To constraint the nuclear models and complete fragmentation cross sections databases; our collaboration has performed an experiment on May 2008 at GANIL with a 95 MeV/u 12C beam. We have measured the fluence, energy and angular distributions of charged fragments and neutrons coming from nuclear reactions of incident 12C on thick water-like PMMA targets. Preliminary comparisons between GEANT4 (G4BinaryLightIonReaction) simulations and experimental data show huge discrepancies.

  3. Hadron Cancer Therapy: Role of Nuclear Reactions

    Science.gov (United States)

    Chadwick, M. B.

    2000-06-20

    Recently it has become feasible to calculate energy deposition and particle transport in the body by proton and neutron radiotherapy beams, using Monte Carlo transport methods. A number of advances have made this possible, including dramatic increases in computer speeds, a better understanding of the microscopic nuclear reaction cross sections, and the development of methods to model the characteristics of the radiation emerging from the accelerator treatment unit. This paper describes the nuclear reaction mechanisms involved, and how the cross sections have been evaluated from theory and experiment, for use in computer simulations of radiation therapy. The simulations will allow the dose delivered to a tumor to be optimized, whilst minimizing the dos given to nearby organs at risk.

  4. Breakup fusion theory of nuclear reactions

    International Nuclear Information System (INIS)

    Continuum spectra of particles emitted in incomplete fusion reactions are one of the major interests in current nuclear reaction studies. Based on an idea of the so-called breakup fusion (BF) reaction, several authors derived closed formulas for the singles cross section of the particles that are emitted. There have been presented, however, two conflicting cross section formulas for the same BF reaction. For convenience, we shall call one of them the IAV (Ichimura, Austern and Vincent) and the other UT (Udagawa and Tamura) cross section formulas. In this work, the formulation of the UT cross section formula (prior-form) is presented, and the post-form version of the IAV cross section formula is evaluted for a few α- and d-induced reactions based on the exact finite range method. It is shown that the values thus calculated are larger by an order of magnitude as compared with the experimental cross sections for the α-induced reactions, while they are comparable with the experimental cross sections for the d-induced reactions. A possible origin of why such a large cross section is resulted in the case of α-induced reactions is also discussed. Polarization of the residual compound nucleus produced in breakup fusion reactions are calculated and compared with experiments. It is shown that the polarization is rather sensitive to the deflection angles of the strongly absortive partial waves and to obtain a good fit with the experimental data a l-dependent potential in the incident channel is needed in order to stress the lower partial waves

  5. Images of mycobacterium for nuclear reactions

    International Nuclear Information System (INIS)

    According to the World Health Organization (WHO) tuberculosis is responsible for 2.9 million deaths annually worldwide. The necessity for optimizing time to detect the tuberculosis bacillus (mycobacterium tuberculosis) in the sputum samples of affected individuals (TB patients) led to the development of a methodology based on the doping with boron of the bacillus, submission of the samples to thermal neutron beam and ionizing particles, generating nuclear reactions of the types: 10B (n,α)7Li and 10 B(α, p)13C. Images of these bacilli are obtained by means of the nuclear tracks produced in the CR-39 detector for particles products of these nuclear reactions, α and p. When the CR-39 is submitted to a chemical attack the traces are developed and the images of the microorganisms registered in the detector can be observed with a conventional light microscope, characterizing them by morphology. The use of this methodology results in images of the mycobacterium tuberculosis becoming more defined and enlarged than those obtained by bacilloscopy, in which the sample is submitted to the method of coloration of Ziehl-Neelsen (ZN) and observed in light microscopy. (author)

  6. Effect of nuclear-reaction mechanisms on the population of excited nuclear states and isomeric ratios

    Science.gov (United States)

    Skobelev, N. K.

    2016-07-01

    Experimental data on the cross sections for channels of fusion and transfer reactions induced by beams of radioactive halo nuclei and clustered and stable loosely bound nuclei were analyzed, and the results of this analysis were summarized. The interplay of the excitation of single-particle states in reaction-product nuclei and direct reaction channels was established for transfer reactions. Respective experiments were performed in stable (6Li) and radioactive (6He) beams of the DRIBs accelerator complex at the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, and in deuteron and 3He beams of the U-120M cyclotron at the Nuclear Physics Institute, Academy Sciences of Czech Republic (Řež and Prague, Czech Republic). Data on subbarrier and near-barrier fusion reactions involving clustered and loosely bound light nuclei (6Li and 3He) can be described quite reliably within simple evaporation models with allowance for different reaction Q-values and couple channels. In reactions involving halo nuclei, their structure manifests itself most strongly in the region of energies below the Coulomb barrier. Neutron transfer occurs with a high probability in the interactions of all loosely bound nuclei with light and heavy stable nuclei at positive Q-values. The cross sections for such reactions and the respective isomeric ratios differ drastically for nucleon stripping and nucleon pickup mechanisms. This is due to the difference in the population probabilities for excited single-particle states.

  7. High energy nuclear collective effects in photo-nuclear reactions

    International Nuclear Information System (INIS)

    High energy nuclear collective effects in (γ,p) reactions on medium weight nuclei have been studied. Incident photon energies, which are determined with a photon tagging system, are from 327 to 527 MeV with a 40 MeV step. Inclusive proton momentum spectra covered from 300 to 900 MeV/c at backward angles, 90 deg to 150 deg, are analyzed in terms of a local equilibrium model. The size and effective mass of a localized hot nuclear matter (fireball) created in the target nucleus are estimated from their recoil velocity, which is determined to fit the proton spectrum based on an evaporation model. Also estimated are the thermodynamical properties, such as the temperature, energy density, lifetime, relaxation time etc. The temperature of the excited nuclear matter extracted from the proton spectrum is much lower, about 30 % typically, than that expected from the deposited energy by the reaction. It suggests that the temperature of the created matter is reduced by the sudden change of the density. Accordingly, the nuclear thermal compressibility is estimated to be about 230 MeV from the information of the temperature, pressure and density. On the space-time consideration, however, many difficulities appear in the fireball formation, which may be universal in all of the hadron statistical model. A new collective model in high energy nuclear structure is proposed within the framework of quantum chromodynamics (QCD) to describe the fireball formation mechanism and their decay process, based on a bag picture including their space-time properties. (author)

  8. Performance Improvements for Nuclear Reaction Network Integration

    CERN Document Server

    Longland, Richard; José, Jordi

    2014-01-01

    Aims: The aim of this work is to compare the performance of three reaction network integration methods used in stellar nucleosynthesis calculations. These are the Gear's backward differentiation method, Wagoner's method (a 2nd-order Runge-Kutta method), and the Bader-Deuflehard semi-implicit multi-step method. Methods: To investigate the efficiency of each of the integration methods considered here, a test suite of temperature and density versus time profiles is used. This suite provides a range of situations ranging from constant temperature and density to the dramatically varying conditions present in white dwarf mergers, novae, and x-ray bursts. Some of these profiles are obtained separately from full hydrodynamic calculations. The integration efficiencies are investigated with respect to input parameters that constrain the desired accuracy and precision. Results: Gear's backward differentiation method is found to improve accuracy, performance, and stability in integrating nuclear reaction networks. For te...

  9. Recent Developments in the Experimental Nuclear Reaction Data Library EXFOR

    OpenAIRE

    Semkova Valentina; Otuka Naohiko; Simakov Stanislav; Zerkin Viktor

    2014-01-01

    The International Network of Nuclear Reaction Data Centres (NRDC) provides nuclear reaction data services to users through collection and compilation of experimental nuclear reaction data in the EXFOR database. The database includes neutron-induced, charged-particle-induced, and photonuclear data for projectile energies up to 1 GeV. Sophisticated search options and user-friendly retrieval interface for downloading data in different formats have been developed at IAEA Nuclear Data Section. Add...

  10. Low energy nuclear reactions: 2007 update

    International Nuclear Information System (INIS)

    Introduction: This paper presents an overview of the field of low energy nuclear reactions (LENR), a branch of condensed matter nuclear science. It explains some of the various terminologies that have been used to describe this field since it debuted as 'cold fusion' in 1989. The paper also reviews some of the most interesting news and developments regarding low energy nuclear reaction experiments and theory, and some of the sociological and political trends that have affected the field over the last 18 years. It concludes with a list of resources and information for scientists, journalists and decision makers. Understanding the Nature of the Reactions The worldwide LENR research effort includes 200 researchers in 13 nations. Over the last 18 years, 12 international conferences have been held, as well as 7 regional conferences in Italy, 14 in Russia and 7 in Japan. The significant questions that face this field of research are: a) Are LENRs a genuine nuclear reaction? b) If so, is there a release of excess energy? and c) Are transmutations possible? If the answers to these questions turn out to be positive, the next questions will be: d) Is the energy release cost-effective? and e) Are the transmutations useful? Despite the fact that repeatability and reproducibility are challenging, the required parameters for achieving the excess heat effect are well understood. First, a high atomic loading ratio of D into Pd is required. In most conditions, 0.90 is the minimum threshold required to produce an excess heat effect. Second, a high electrical current density in the cathode is needed, 250 mA/cm2 under most conditions. The third requirement is for some kind of dynamic trigger to impose a deuterium flux in, on or around the cathode. The challenge that researchers face is how to achieve these conditions. Some of the Most Interesting Research Developments Work by Stanislaw Szpak, Pamela Boss and Frank Gordon at the U.S. Navy's SPAWAR Systems Center in San Diego has

  11. Nuclear reactions in Monte Carlo codes

    CERN Document Server

    Ferrari, Alfredo

    2002-01-01

    The physics foundations of hadronic interactions as implemented in most Monte Carlo codes are presented together with a few practical examples. The description of the relevant physics is presented schematically split into the major steps in order to stress the different approaches required for the full understanding of nuclear reactions at intermediate and high energies. Due to the complexity of the problem, only a few semi-qualitative arguments are developed in this paper. The description will be necessarily schematic and somewhat incomplete, but hopefully it will be useful for a first introduction into this topic. Examples are shown mostly for the high energy regime, where all mechanisms mentioned in the paper are at work and to which perhaps most of the readers are less accustomed. Examples for lower energies can be found in the references. (43 refs) .

  12. Prompt nuclear analysis bibliography 1976

    International Nuclear Information System (INIS)

    A prompt nuclear analysis bibliography published in 1974 has been updated to include literature up to the end of 1976. The number of publications has more than doubled since mid-1973. The bibliography is now operated as a computer file and searches can be made on key words and parameters. Tables of references are given for each of the categories: backscattering, ion-ion, ion-gamma, ion-neutron, neutron-gamma, neutron-neutron and gamma-ray-induced reactions

  13. Thermal release of tritium implanted in graphite studied by T(d,α)n nuclear reaction depth profiling analysis

    International Nuclear Information System (INIS)

    Specimens of graphite from limiter tiles in JET were implanted at room temperature with HT+ and DT+ ions at energies in the range 10-50 keV and at fluences between 5x1014 and 3x1016 ions/cm2, using the isotope separator. Depth profiles of tritium were measured by the T(d,α)n reaction using glancing incidence of the incoming 500 keV D2+ ions and detecting the outgoing α particles in a forward direction. Considerable broadening of the experimentally obtained depth profiles was observed as compared to calculated ones. For a specimen implanted with 5x1015 HT+ ions/cm2 at 40 keV, the depth profiles of tritium were studied as a function of isochronal annealing in vacuum up to ≅ 700 K. It was found that the release of tritium proceeds essentially without any change in the depth profile. Implanted tritium stars to be detrapped around 600 K, reaches a maximum in its release rate at 1100-1400 K and is 95% released at 1600 K. The obtained release curve is consistent with that obtained by other investigators for deuterium implanted at fluences of ≅ 1016-1017 D+ ions/cm2, and it is shifted to ≅ 200-300 K higher temperatures compared to the case of ≅ 1018-1019/cm2 deuterium fluences. The observed behaviour is believed to be indicative of a single-step detrapping and recombination mechanism of implanted tritium ions, and its subsequent fast transgranular diffusion as molecules. (orig.)

  14. Reactions of charged and neutral recoil particles following nuclear transformations

    International Nuclear Information System (INIS)

    The status of the following programs is reported: study of the stereochemistry of halogen atom or ion reactions produced via (eta,γ) or (IT) nuclear reactions with diastereomeric molecules; study of nuclear decay induced reactions of halogen species with organic compounds in the gas phase; decay-induced labelling of compounds of biochemical interest; energetics and mechanisms involved in the reactions of highly energetic carbon-11 atoms with simple organic molecules; and chemistry of the positronium. (LK)

  15. Identifying Understudied Nuclear Reactions by Text-mining the EXFOR Experimental Nuclear Reaction Library

    Science.gov (United States)

    Hirdt, J. A.; Brown, D. A.

    2016-01-01

    The EXFOR library contains the largest collection of experimental nuclear reaction data available as well as the data's bibliographic information and experimental details. We text-mined the REACTION and MONITOR fields of the ENTRYs in the EXFOR library in order to identify understudied reactions and quantities. Using the results of the text-mining, we created an undirected graph from the EXFOR datasets with each graph node representing a single reaction and quantity and graph links representing the various types of connections between these reactions and quantities. This graph is an abstract representation of the connections in EXFOR, similar to graphs of social networks, authorship networks, etc. We use various graph theoretical tools to identify important yet understudied reactions and quantities in EXFOR. Although we identified a few cross sections relevant for shielding applications and isotope production, mostly we identified charged particle fluence monitor cross sections. As a side effect of this work, we learn that our abstract graph is typical of other real-world graphs.

  16. Theoretical studies in nuclear reactions and nuclear structure: Progress report

    International Nuclear Information System (INIS)

    This report discusses topics in nuclear theory. These general topics are: Quark physics, Quantum field theory, Relativistic nuclear physics, Nuclear dynamics, and Few-body problems and nonrelativistic methods

  17. Deexcitation Modes in Spallation Nuclear Reactions

    Science.gov (United States)

    Velasco, F. G.; Guzmán, F.; Rodriguez, O.; Tumbarell, O.; Souza, D. A.; Samana, A. R.; Andrade-II, E.; Bernal Castillo, J. L.; Deppman, A.

    2016-08-01

    Spallation nuclear reactions in the range of 0.2 to 1.2 GeV are studied using the CRISP code. A new approach for the deexcitation stage of the compound nucleus was introduced. For the calculations of the level densities, this approach is based on the Back-shifted Fermi gas model (BSFG), which takes into account pairing effects and shell corrections, whereas the calculation of the fission barriers were performed by means of the Extended Thomas-Fermi plus Strutinsky Integral (ETFSI) method, which is a high-speed approximation to the Hartree-Fock method with pairing correlations treated as in the usual BCS plus blocking approach. This procedure is more appropriate to calculate level densities for exotic nuclei. Satisfactory results were obtained and compared with experimental data obtained in the GSI experiments. As another important result, we highlight some directions for the development of a qualitatively superior version of the CRISP code with the implementation of more realistic and suitable physical models to be applied in stable and exotic nuclei that participate in the process. This new version of the code includes several substantial changes in the decay of the hot compound nucleus which allow satisfactory agreement with the experimental data and a reduction of the adjustment parameters.

  18. Solar He-3: Information from nuclear reactions in flares

    Science.gov (United States)

    Ramaty, R.; Kozlovsky, B.

    1974-01-01

    Information on solar He-3 from nuclear reactions in flares was considered. Consideration was also given to the development of models for these reactions as well as the abundance of He-3 in the photosphere. Data show that abundances may be explained by nuclear reactions of flare acceleration protons and alpha particles with the ambient atmosphere, provided that various assumptions are made on the directionality of the interacting beams and acceleration of the particles after production.

  19. [Reaction mechanism studies of heavy ion induced nuclear reactions

    International Nuclear Information System (INIS)

    This report contains papers that discuss: Target Dependence of Complex Fragment Emission in 47-MeV/u La-Induced Reactions; Deconvolution of Time-of-Flight Data to Improve Mass Identification; and Study of the Reaction of La + Al at E/A = 50 MeV with Landau-Vlasov Dynamics

  20. Low energy reaction data relevant for nuclear energy systems

    International Nuclear Information System (INIS)

    The study of the nuclear data for both the light and heavy ion induced reactions has been a topic of interest not only from the basic physics point of view, but also due to the requirement of such data for the research and development of various nuclear energy systems. As such, the data particularly the nuclear reaction cross-sections are needed over a wide range of energy and projectile-target combinations. The topic of research in this field has been of interest recently, due to the research and development of recently proposed Accelerator Driven Sub-critical (ADS) reactor systems. However, the design of ADS is not plausible with limited nuclear reaction cross-section data. Hence, more experimental data is required to determine the optimum irradiation conditions for producing radioactive isotopes of interest. Though, measurement and analysis of the production of fusion and fission residues in heavy ion (HI) interactions have been extensively carried out during the last few years but proper understanding of dynamics of HI reactions is still lacking. Reactions induced by HIs are important, because large input angular momentum is involved and, therefore, the composite system may be produced with relatively high spin. Also, HIs have been used as projectile to study the splitting of excited composite system leading to the production of fusion-fission or quasi-fission events over a wide range of fissility (Z2/A), excitation energy (E*) and entrance channel angular momentum. In view of the above, experimental studies for 13C+169Tm system have been performed at the Inter University Accelerator Centre (IUAC), New Delhi, India using the recoil-catcher technique followed by off-line γ - spectroscopy. In the present work, production cross-section of a large number of fission-like residues have been measured at ≈ 85 MeV, projectile energy. Distribution of the cross-section with respect to the mass number (A) of the residues has been studied in order to understand the route

  1. Nuclear Fission: Reaction to the Discovery in 1939

    OpenAIRE

    Hodes, Elizabeth; Tiddens, Adolph; Badash, Lawrence

    1985-01-01

    An examination of the initial reactions to the first laboratory based fission reaction, this document parallels the event to the openning of Pandora's box. Not only are the reactions to the benefits of Nuclear power analyzed but also the detrimental effects and negative applications.

  2. Effects of Neutron Skin Thickness in Peripheral Nuclear Reactions

    Institute of Scientific and Technical Information of China (English)

    FANG De-Qing; MA Yu-Gang; CAI Xiang-Zhou; TIAN Wen-Dong; WANG Hong-Wei

    2011-01-01

    Effects of neutron skin thickness in peripheral nuclear collisions are investigated using the statistical abrasion ablation (SAA) model. The reaction cross section, neutron (proton) removal cross section, one-neutron (proton) removal cross section as well as their ratios for nuclei with different neutron skin thickness are studied. It is demonstrated that there are good linear correlations between these observables and the neutron skin thickness for neutron-rich nuclei. The ratio between the (one-)neutron and proton removal cross section is found to be the most sensitive observable of neutron skin thickness. Analysis shows that the relative increase of this ratio could be used to determine the neutron skin size in neutron-rich nuclei.%Effects of neutron skin thickness in peripheral nuclear collisions are investigated using the statistical abrasion ablation (SAA ) model.The reaction cross section,neutron (proton) removal cross section,one-neutron (proton) removal cross section as well as their ratios for nuclei with different neutron skin thickness are studied.It is demonstrated that there are good linear correlations between these observables and the neutron skin thickness for neutron-rich nuclei.The ratio between the (one-)neutron and proton removal cross section is found to be the most sensitive observable of neutron skin thickness.Analysis shows that the relative increase of this ratio could be used to determine the neutron skin size in neutron-rich nuclei.Determining the size and shape of a nucleus is one of the most important subjects since the discovery of atomic nuclei.The rms radii of the neutron (rn) and proton (rp) density distributions are among the most prominent observables for this purpose.Studies for stable nuclei have shown that the nuclear radii are proportional to A1/3,with A being the nuclear mass number.Meanwhile,the density distributions of neutrons and protons in stable nuclei are very similar.

  3. Materials analysis with a nuclear microprobe

    International Nuclear Information System (INIS)

    The ability to produce focused beams of a few MeV light ions from Van de Graaff accelerators has resulted in the development of nuclear microprobes. Rutherford backscattering, nuclear reactions, and particle-induced x-ray emission are used to provide spatially resolved information from the near surface region of materials. Rutherford backscattering provides nondestructive depth and mass resolution. Nuclear reactions are sensitive to light elements (Z < 15). Particle-induced x-ray analysis is similar to electron microprobe analysis, but 2 orders of magnitude more sensitive. The focused beams are usually produced with specially designed multiplets of magnetic quadrupoles. The LASL microprobe uses a superconducting solenoid as a final lens. The data are acquired by a computer interfaced to the experiment with CAMAC. The characteristics of the information acquired with a nuclear microprobe are discussed; the means of producing the beams of nuclear particles are described; and the limitations and applications of such systems are given

  4. Reaction matrix in nuclear shell theory

    Energy Technology Data Exchange (ETDEWEB)

    Macfarlane, M.H.

    1967-09-01

    Lectures are given in which the nuclear shell model is discussed as a link between the properties of complex nuclei and the free-nucleon interaction. A version of the shell model is derived from nuclear many-body theory, and also this version is compared and contrasted with phenomenological shell theory. Attention is focused on oxygen-18 and fluorine-18. 76 references. (JFP)

  5. Nuclear reaction modeling, verification experiments, and applications

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, F.S.

    1995-10-01

    This presentation summarized the recent accomplishments and future promise of the neutron nuclear physics program at the Manuel Lujan Jr. Neutron Scatter Center (MLNSC) and the Weapons Neutron Research (WNR) facility. The unique capabilities of the spallation sources enable a broad range of experiments in weapons-related physics, basic science, nuclear technology, industrial applications, and medical physics.

  6. BRUSLIB and NETGEN: the Brussels nuclear reaction rate library and nuclear network generator for astrophysics

    OpenAIRE

    Aikawa, M.; Arnould, M.; Goriely, S.; Jorissen, A.; Takahashi, K.

    2005-01-01

    Nuclear reaction rates are quantities of fundamental importance in astrophysics. Substantial efforts have been devoted in the last decades to measure or calculate them. The present paper presents for the first time a detailed description of the Brussels nuclear reaction rate library BRUSLIB and of the nuclear network generator NETGEN so as to make these nuclear data packages easily accessible to astrophysicists for a large variety of applications. BRUSLIB is made of two parts. The first one c...

  7. Theoretical studies in nuclear reactions and nuclear structure

    International Nuclear Information System (INIS)

    Research in the Maryland Nuclear Theory Group focusses on problems in four basic areas of current relevance. Hadrons in nuclear matter; the structure of hadrons; relativistic nuclear physics and heavy ion dynamics and related processes. The section on hadrons in nuclear matter groups together research items which are aimed at exploring ways in which the properties of nucleons and the mesons which play a role in the nuclear force are modified in the nuclear medium. A very interesting result has been the finding that QCD sum rules supply a new insight into the decrease of the nucleon's mass in the nuclear medium. The quark condensate, which characterizes spontaneous chiral symmetry breaking of the late QCD vacuum, decreases in nuclear matter and this is responsible for the decrease of the nucleon's mass. The section on the structure of hadrons contains progress reports on our research aimed at understanding the structure of the nucleon. Widely different approaches are being studied, e.g., lattice gauge calculations, QCD sum rules, quark-meson models with confinement and other hedgehog models. A major goal of this type of research is to develop appropriate links between nuclear physics and QCD. The section on relativistic nuclear physics represents our continuing interest in developing an appropriate relativistic framework for nuclear dynamics. A Lorentz-invariant description of the nuclear force suggests a similar decrease of the nucleon's mass in the nuclear medium as has been found from QCD sum rules. Work in progress extends previous successes in elastic scattering to inelastic scattering of protons by nuclei. The section on heavy ion dynamics and related processes reports on research into the e+e- problem and heavy ion dynamics

  8. Microscopic effective reaction theory for direct nuclear reactions

    Directory of Open Access Journals (Sweden)

    Ogata Kazuyuki

    2016-01-01

    Full Text Available Some recent activities with the microscopic effective reaction theory (MERT on elastic, inelastic, breakup, transfer, and knockout processes are reviewed briefly. As a possible alternative to MERT, a description of elastic and inelastic scattering with the continuum particle-vibration coupling (cPVC method is also discussed.

  9. International conference: Features of nuclear excitation states and mechanisms of nuclear reactions. 51. Meeting on nuclear spectroscopy and nuclear structure. The book of abstracts

    International Nuclear Information System (INIS)

    Results of the LI Meeting on Nuclear Spectroscopy and Nuclear Structure are presented. Properties of excited states of atomic nuclei and mechanisms of nuclear reactions are considered. Studies on the theory of nucleus and fundamental interactions pertinent to experimental study of nuclei properties and mechanisms of nuclear reactions, technique and methods of experiment, application of nuclear-physical method, are provided

  10. Key nuclear reaction experiments discoveries and consequences

    CERN Document Server

    Paetz gen. Schieck, Hans

    2015-01-01

    In this book the author charts the developments in nuclear physics since its inception around a century ago by reviewing the key experiments that helped drive and shape our understanding of the field, especially in the context of the wider developments in physics in the early 20th Century. In addition to providing a path through the field and the crucial events it looks at how these experiments not only answered key questions at the time but presented new challenges to the contemporary perception of the nuclear and sub-atomic worlds and how they helped develop our present understanding of nuclear physics.

  11. The nuclear structure and low-energy reactions (NSLER) collaboration

    Science.gov (United States)

    Dean, D. J.; NSLER Collaboration

    2006-09-01

    The long-term vision of the Nuclear Structure and Low-Energy Reactions (NSLER) collaboration is to arrive at a comprehensive and unified description of nuclei and their reactions that is grounded in the interactions between the constituent nucleons. For this purpose, we will develop a universal energy density functional for nuclei and replace current phenomenological models of nuclear structure and reactions with a well-founded microscopic theory that will deliver maximum predictive power with minimal uncertainties that are well quantified. Nuclear structure and reactions play an essential role in the science to be investigated at rare isotope facilities, and in nuclear physics applications to the Science-Based Stockpile Stewardship Program, next-generation reactors, and threat reduction. We anticipate an expansion of the computational techniques and methods we currently employ, and developments of new treatments, to take advantage of petascale architectures and demonstrate the capability of the leadership class machines to deliver new science heretofore impossible.

  12. BRUSLIB and NETGEN: the Brussels nuclear reaction rate library and nuclear network generator for astrophysics

    CERN Document Server

    Aikawa, M; Goriely, S; Jorissen, A; Takahashi, K

    2005-01-01

    Nuclear reaction rates are quantities of fundamental importance in astrophysics. Substantial efforts have been devoted in the last decades to measure or calculate them. The present paper presents for the first time a detailed description of the Brussels nuclear reaction rate library BRUSLIB and of the nuclear network generator NETGEN so as to make these nuclear data packages easily accessible to astrophysicists for a large variety of applications. BRUSLIB is made of two parts. The first one contains the 1999 NACRE compilation based on experimental data for 86 reactions with (mainly) stable targets up to Si. The second part of BRUSLIB concerns nuclear reaction rate predictions calculated within a statistical Hauser-Feshbach approximation, which limits the reliability of the rates to reactions producing compound nuclei with a high enough level density. These calculations make use of global and coherent microscopic nuclear models for the quantities entering the rate calculations. The use of such models is utterl...

  13. Electromagnetic studies of nuclear structure and reactions

    International Nuclear Information System (INIS)

    This report contains papers on the following topics: giant resonance studies; deep inelastic scattering studies; high resolution nuclear structure work; and relativistic RPA; and field theory in the Schroedinger Representation

  14. Electromagnetic studies of nuclear structure and reactions

    Energy Technology Data Exchange (ETDEWEB)

    Hersman, F.W.; Dawson, J.F.; Heisenberg, J.H.; Calarco, J.R.

    1990-06-01

    This report contains papers on the following topics: giant resonance studies; deep inelastic scattering studies; high resolution nuclear structure work; and relativistic RPA; and field theory in the Schroedinger Representation.

  15. Theoretical studies in nuclear reactions and nuclear structure

    International Nuclear Information System (INIS)

    During the past year, research in theoretical nuclear physics at the University of Maryland attained a number of exciting and important results. These are described in some detail throughout the report, but some of the highlights are as follows: large Nc QCD has been shown to place strong constraints on vacuum effects of hadronic field theories; color dielectric models of hadrons have been understood in terms of lattice QCD; we have completed a relativistic analysis of proton scattering to test virtual pair contributions; we have also re-derived the Mandelzweig-Wallace two-body Dirac equation in covariant form, and applied it to the atomic two-body bound states: hydrogen, muonium and positronium; we have carried out the first calculation of the triton binding energy with a realistic quark-based nucleon-nucleon interaction and have learned that new kinds of nonlocalities in the tensor force may produce unexpected results; and we have shown that the Quadronium Conjecture can lead to spontaneous creation of the atom with low momentum as required by the observations, and are constructing a model to quantify the Quadronium phenomenology of the e+e- Puzzle

  16. Charged-Particle Thermonuclear Reaction Rates: III. Nuclear Physics Input

    OpenAIRE

    Iliadis, Christian; Longland, Richard; Champagne, Art; Coc, Alain

    2010-01-01

    The nuclear physics input used to compute the Monte Carlo reaction rates and probability density functions that are tabulated in the second paper of this series (Paper II) is presented. Specifically, we publish the input files to the Monte Carlo reaction rate code RatesMC, which is based on the formalism presented in the first paper of this series (Paper I). This data base contains overwhelmingly experimental nuclear physics information. The survey of literature for this review was concluded ...

  17. Direct reactions for nuclear structure and nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Katherine Louise [Univ. of Tennessee, Knoxville, TN (United States)

    2014-12-18

    Direct reactions are powerful probes for studying the atomic nucleus. Modern direct reaction studies are illuminating both the fundamental nature of the nucleus and its role in nucleosynthetic processes occurring in the cosmos. This report covers experiments using knockout reactions on neutron-deficient fragmentation beams, transfer reactions on fission fragment beams, and theoretical sensitivity studies relating to the astrophysical r-process. Results from experiments on 108,106Sn at the NSCL, and on 131Sn at HRIBF are presented as well as the results from the nucleosynthesis study.

  18. A method of analysing experimental data of nuclear reaction cross sections

    Institute of Scientific and Technical Information of China (English)

    FengJun; ShenWen-Qing

    1997-01-01

    A method of analysing experimental data of nuclear reaction cross sections σr induced by radioactive beam is described.It can be used in analysis of experimental unclear reaction cross section data obtained by Na-isopope radioactive beams on different targets.Neutron halo has not been found in these nuclei.

  19. Unitary correlation in nuclear reaction theory

    OpenAIRE

    Mukhamedzhanov, A. M.; Kadyrov, A. S.

    2010-01-01

    We prove that the amplitudes for the (d,p), (d,pn) and (e,e'p) reactions determining the asymptotic behavior of the exact scattering wave functions in the corresponding channels are invariant under unitary correlation operators while the spectroscopic factors are not. Moreover, the exact reaction amplitudes are not parametrized in terms of the spectroscopic factors and cannot provide a tool to determine the spectroscopic factors.

  20. Three-body direct nuclear reactions: Nonlocal optical potential

    OpenAIRE

    Deltuva, A

    2009-01-01

    The calculations of three-body direct nuclear reactions with nonlocal optical potentials are performed for the first time using the framework of Faddeev-type scattering equations. Important nonlocality effect is found for transfer reactions like d+16O -> p + 17O often improving the description of the experimental data.

  1. Nuclear Many-Body Physics Where Structure And Reactions Meet

    OpenAIRE

    Ahsan, Naureen; Volya, Alexander

    2009-01-01

    The path from understanding a simple reaction problem of scattering or tunneling to contemplating the quantum nuclear many-body system, where structure and continuum of reaction-states meet, overlap and coexist, is a complex and nontrivial one. In this presentation we discuss some of the intriguing aspects of this route.

  2. Economic Analysis of Nuclear Energy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Man Ki; Moon, K. H.; Kim, S. S.; Lim, C. Y.; Oh, K. B

    2006-12-15

    It has been well recognized that securing economic viabilities along with technologies are very important elements in the successful implementation of nuclear R and D projects. The objective of the Project is to help nuclear energy to be utilized in an efficient way by analyzing major issues related with nuclear economics. The study covers following subjects: the role of nuclear in the future electric supply system, economic analysis of nuclear R and D project, contribution to the regional economy from nuclear power. In addition, the study introduces the international cooperation in the methodological area of efficient use of nuclear energy by surveying the international activities related with nuclear economics.

  3. Studying Nuclear Level Densities of 238U in the Nuclear Reactions within the Macroscopic Nuclear Models

    Science.gov (United States)

    Razavi, Rohallah; Rahmatinejad, Azam; Kakavand, Tayeb; Taheri, Fariba; Aghajani, Maghsood; Khooy, Asghar

    2016-02-01

    In this work the nuclear level density parameters of 238U have been extracted in the back-shifted Fermi gas model (BSFGM), as well as the constant temperature model (CTM), through fitting with the recent experimental data on nuclear level densities measured by the Oslo group. The excitation functions for 238U(p,2nα)233Pa, and 238U(p,4n)235Np reactions and the fragment yields for the fragments of the 238U(p,f) reaction have been calculated using obtained level density parameters. The results are compared to their corresponding experimental values. It was found that the extracted excitation functions and the fragment yields in the CTM coincide well with the experimental values in the low-energy region. This finding is according to the claim made by the Oslo group that the extracted level densities of 238U show a constant temperature behaviour.

  4. Opportunities in nuclear structure and reactions

    Science.gov (United States)

    Nunes, Filomena

    2015-10-01

    The last decade has seen important advances in the area of low energy nuclear physics. New measurements have provided crucial insight into the behavior of nuclei at the limits of stability, including the mapping of the neutron dripline up to Oxygen, investigations of unbound nuclear states, and the discovery of new super-heavy elements. In parallel we have seen a revolution in low-energy nuclear theory, moving toward quantified predictability, rooted in the underlying inter-nucleon forces. But the next decade offers even more opportunities with a new generation factory of rare isotopes, and the anticipated developments in high performance computing. The Facility for Rare Isotope Beams coupled with new state-of-the-art detectors will allow us to access a large fraction of the necessary information for the r-process responsible for making at least half of the heavy elements in our universe. FRIB will provide the needed intensities to study global nuclear properties, shell structure, and collective phenomena far from stability. Key measurements are anticipated, at various facilities, which will inform symmetry tests with rare isotopes. We expect to put strict constraints on the equation of state. These and many other opportunities will be highlighted in this overview talk.

  5. From Stopping to Viscosity in Nuclear Reactions

    OpenAIRE

    Danielewicz, P.; Barker, B.; Shi, L.

    2009-01-01

    Data on stopping in intermediate-energy central heavy-ion collisions are analyzed following transport theory based on the Boltzmann equation. In consequence, values of nuclear shear viscosity are inferred. The inferred values are significantly larger than obtained for free nucleon dispersion relations and free nucleon-nucleon cross sections.

  6. Physical Mechanism of Nuclear Reactions at Low Energies

    CERN Document Server

    Oleinik, V P; Arepjev, Yu.D

    2002-01-01

    The physical mechanism of nuclear reactions at low energies caused by spatial extension of electron is considered. Nuclear reactions of this type represent intra-electronic processes, more precisely, the processes occurring inside the area of basic localization of electron. Distinctive characteristics of these processes are defined by interaction of the own field produced by electrically charged matter of electron with free nuclei. Heavy nucleus, appearing inside the area of basic localization of electron, is inevitably deformed because of interaction of protons with the adjoining layers of electronic cloud, which may cause nuclear fission. If there occur "inside" electron two or greater number of light nuclei, an attractive force appears between the nuclei which may result in the fusion of nuclei. The intra-electronic mechanism of nuclear reactions is of a universal character. For its realization it is necessary to have merely a sufficiently intensive stream of free electrons, i.e. heavy electric current, an...

  7. High energy photons production in nuclear reactions

    International Nuclear Information System (INIS)

    Hard photon production, in nucleus-nucleus collisions, were studied at beam energies between 10 and 125 MeV. The main characteristics of the photon emission are deduced. They suggest that the neutron-proton collisions in the early stage of the reaction are the main source of high energy gamma-rays. An overview of the theoretical approaches is given and compared with experimental results. Theoretical attempts to include the contribution of charged pion exchange currents to photon production, in calculations of proton-nucleus-gamma and nucleus-nucleus-gamma reactions, showed suitable fitting with experimental data

  8. Opportunities for nuclear reaction studies at future facilities

    CERN Document Server

    Veselsky, Martin; Vujisicova, Nikoleta; Souliotis, Georgios A

    2016-01-01

    Opportunities for investigations of nuclear reactions at the future nuclear physics facilities such as radioactive ion beam facilities and high-power laser facilities are considered. Post-accelerated radioactive ion beams offer possibilities for study of the role of isospin asymmetry in the reaction mechanisms at various beam energies. Fission barrier heights of neutron-deficient nuclei can be directly determined at low energies. Post-accelerated radioactive ion beams, specifically at the future facilities such as HIE-ISOLDE, SPIRAL-2 or RAON-RISP can be also considered as a candidate for production of very neutron-rich nuclei via mechanism of multi-nucleon transfer. High-power laser facilities such as ELI-NP offer possibilities for nuclear reaction studies with beams of unprecedented properties. Specific cases such as ternary reactions or even production of super-heavy elements are considered.

  9. Nuclear excitations and reaction mechanisms: Progress report

    International Nuclear Information System (INIS)

    This report describes activities of the Nuclear Theory Group at Brown University during the period 1 August 1987-31 July 1988, under Grant FG02-87ER40334. Completed and on-going research includes various theoretical and numerical studies on: parity non-conserving interactions in a relativistic system, processes involving virtual photons and real photons, deuteron-nucleus and neutron-deuteron collisions systems, and muon-catalyzed fusion

  10. Derivation of Energy Generated by Nuclear Fission-Fusion Reaction

    OpenAIRE

    Kayano, Hideo; Teshigawara, Makoto; Konashi, Kenji; Yamamoto, Takuya

    1994-01-01

    In the solids which contain fissionable elements and deuterium, it is expected that the energy generated by nuclear fission contributes to the promotion of the D-D nuclear fusion in the solids. When nuclear fission occurs by neutrons in the solid, the fissionable elements divide into two fission product nuclei having the energy of 100MeV, respectively. It is expected that the hige energy fission products promote rapidly nuclear fision reaction by knocking out the D atoms in the solids and by ...

  11. Experimental approaches to nuclear reactions involved in explosive stellar binaries

    Energy Technology Data Exchange (ETDEWEB)

    Blackmon, J.C. [Physics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6354 (United States)]. E-mail: blackmon@ornl.gov; Angulo, C. [Centre de Recherches du Cyclotron, Universite catholique de Louvain, 2 Chemin du Cyclotron, B-1348 Louvain-la-Neuve (Belgium); Shotter, A.C. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada)

    2006-10-17

    Explosive stellar environments such as novae and X-ray bursts are currently among the most exciting topics in nuclear astrophysics. Reactions on unstable nuclei play a crucial role in energy generation and nucleosynthesis due to the high temperatures and short reaction time scales in these events, but substantial uncertainties exist in nuclear reaction rates on unstable nuclei resulting from limited experimental data. In recent years some remarkable developments in radioactive ion beam production and experimental techniques have allowed many key reaction rates to be experimentally determined with reasonable accuracy for the first time. In this paper we review experimental methods that have recently been exploited to study reactions important in explosive binaries, highlight some key examples of recent results, and outline remaining experimental challenges.

  12. Improved predictions of nuclear reaction rates with the TALYS reaction code for astrophysical applications

    OpenAIRE

    Goriely, S.; Hilaire, S; Koning, A.J.

    2008-01-01

    Nuclear reaction rates of astrophysical applications are traditionally determined on the basis of Hauser-Feshbach reaction codes. These codes adopt a number of approximations that have never been tested, such as a simplified width fluctuation correction, the neglect of delayed or multiple-particle emission during the electromagnetic decay cascade, or the absence of the pre-equilibrium contribution at increasing incident energies. The reaction code TALYS has been recently updated to estimate t...

  13. Excitation function calculations for α + 93Nb nuclear reactions

    Science.gov (United States)

    Yiğit, M.; Tel, E.; Sarpün, İ. H.

    2016-10-01

    In this study, the excitation functions of alpha-induced reactions on the 93Nb target nucleus were calculated by using ALICE-ASH code. The hybrid model, Weisskopf-Ewing model and geometry dependent hybrid model in this code were used to understand the alpha-niobium interaction. The contribution on the nuclear interaction of compound and pre-compound processes, with variation of the incident alpha particle energy, was presented. Furthermore, the reaction cross sections were calculated by using different level density models such as Superfluid nuclear model, Fermi gas model and Kataria-Ramamurthy Fermi gas model. Obtaining a good agreement between the calculated and the measured cross sections, the exciton numbers and the nuclear level density models were varied. Finally, the proper choice of the exciton numbers and the nuclear level density models was found to be quite important in order to obtain the more realistic cross section values.

  14. EXFOR SYSTEMS MANUAL NUCLEAR REACTION DATA EXCHANGE FORMAT.

    Energy Technology Data Exchange (ETDEWEB)

    MCLANE,V.; NUCLEAR DATA CENTER NETWORK

    2000-05-19

    EXFOR is an exchange format designed to allow transmission of nuclear reaction data between the members of the Nuclear Data Centers Network. This document has been written for use by the members of the Network and includes matters of procedure and protocol, as well as detailed rules for the compilation of data. Users may prefer to consult EXFOR Basics' for a brief description of the format.

  15. Development of the Experimental Photo-Nuclear Reaction Database in Hokkaido University

    Science.gov (United States)

    Makinaga, A.

    2015-10-01

    Nuclear databases are important tools to apply nuclear phenomena to various fields of nuclear engineering. It is now recognized that the databases must be further developed for photo-nuclear reaction data for nuclear security, safety and nonproliferation applications. Hokkaido University Nuclear Reaction Data Centre (JCPRG) has contributed to the Experimental Nuclear Reaction Data Library (EXFOR) which is developed by the International Network of Nuclear Reaction Data Centres under coordination by IAEA. We report here on the recent compilation of the nuclear data files for the photonuclear reaction.

  16. Development of nuclear reaction data retrieval system on Meme media

    International Nuclear Information System (INIS)

    A newly designed retrieval system of charged particle nuclear reaction data is developed on Meme media architecture. We designed the network-based (client-server) retrieval system. The server system is constructed on a UNIX workstation with a relational database, and the client system is constructed on Microsoft Windows PC using an IntelligentPad software package. The IntelligentPad is currently available as developing Meme media. We will develop the system to realize effective utilization of nuclear reaction data: I. 'Re-production, Re-edit, Re-use', II. 'Circulation, Coordination and Evolution', III. 'Knowledge discovery'. (author)

  17. Concrete alkali-silica reaction and nuclear radiation damage

    International Nuclear Information System (INIS)

    The deterioration of concrete by alkali-silica reaction of aggregates (ASR) and the effect of nuclear radiations on the ASR have been reviewed based on our studies on the mechanism of ASR and the effect of nuclear radiations on the resistivity of minerals to alkaline solution. It has been found that the ASR is initiated by the attack of alkaline solution in concrete to silicious aggregates to convert them into hydrated alkali silicate. The consumption of alkali hydroxide by the aggregates induces the dissolution of Ca2+ ions into the solution. The alkali silicate surrounding the aggregates then reacts with Ca2+ ions to convert to insoluble tight and rigid reaction rims. The reaction rim allows the penetration of alkaline solution but prevents the leakage of viscous alkali silicate, so that alkali silicate generated afterward is accumulated in the aggregate to give an expansive pressure enough for cracking the aggregate and the surrounding concrete. The effect of nuclear radiation on the reactivity of quartz and plagioclase, a part of major minerals composing volcanic rocks as popular aggregates, to alkaline solution has been examined for clarifying whether nuclear radiations accelerates the ASR. It has been found that the irradiation of these minerals converts them into alkali-reactive amorphous ones. The radiation dose for plagioclase is as low as 108 Gy, which suggests that the ASR of concrete surrounding nuclear reactors is possible to be accelerated by nuclear radiation. (author)

  18. Relaxation times for angular momentum in damped nuclear reactions

    International Nuclear Information System (INIS)

    The evolution of the angular momentum distribution in damped nuclear reactions is discussed within the framework of the nucleon exchange transport model. First order equations are derived for the time evolution of the mean values and covariances of the spin variables. Solutions are given for 1400 MeV 165Ho + 165Ho reactions at various values of total angular momentum and total kinetic energy loss. Spin dispersions are well described by the calculations

  19. Nuclear reactions induced by high-energy alpha particles

    Science.gov (United States)

    Shen, B. S. P.

    1974-01-01

    Experimental and theoretical studies of nuclear reactions induced by high energy protons and heavier ions are included. Fundamental data needed in the shielding, dosimetry, and radiobiology of high energy particles produced by accelerators were generated, along with data on cosmic ray interaction with matter. The mechanism of high energy nucleon-nucleus reactions is also examined, especially for light target nuclei of mass number comparable to that of biological tissue.

  20. Research in Heavy Ion Nuclear Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Petitt, G.A.; Nelson, W.H.; He, Xiaochun; Lee, W.

    1999-04-14

    This is the final progress report for the experimental nuclear physics program at Georgia State University (GSU) under the leadership of Gus Petitt. In June, 1996, Professor Petitt retired for health reasons and the DOE contract was extended for another year to enable the group to continue it's work. This year has been a productive one. The group has been heavily involved in the E866 experiment at Fermilab where we have taken on the responsibility of developing a new level-3 trigger for the experiment. Bill Lee, the graduate student in our group expects to obtain his thesis data from the run extension currently in progress, which focuses on the A dependence of J/{psi}'s and {Upsilon}'s from beryllium, tungsten, and iron targets. In the past year and a half the GSU group has led the development of a new level-3 software trigger system for E866. Our work on this project is described.

  1. A new Ti/H phase transformation in the H sub 2 sup + titanium alloy studied by x-ray diffraction, nuclear reaction analysis, elastic recoil detection analysis and scanning electron microscopy

    CERN Document Server

    Wang, T; Grambole, D; Grötzschel, R; Herrmann, F; Kreissig, U; Möller, Wolfhard

    2002-01-01

    The titanium hydrogenation process in the H sub 2 sup + implanted Ti225 titanium alloy has been studied in this work. The Ti/H phase transformation from hydrogen solid solution (hcp) to gamma phase titanium hydride (TiH(gamma)) with a primitive tetragonal structure and then to a titanium dihydride (TiH sub 2 (x)) with a body centred tetragonal structure has been characterized by x-ray diffraction, nuclear reaction analysis and elastic recoil detection analysis. This process is very different from the usual hydrogenation mechanism, in which the delta phase titanium dihydride (TiH sub 2 (delta)) with a face centred cubic structure is always involved. Both of the TiH(gamma) and TiH sub 2 (x) are rare phases, which are formed under extreme conditions. The TiH(gamma) was considered to be a metastable phase in low hydrogen concentration titanium, and the TiH sub 2 (x) phase has not yet been notated in the present Ti/H phase list. The characteristics of the TiH sub 2 (x) are unclear, but it is very stable at room te...

  2. Towards a More Complete and Accurate Experimental Nuclear Reaction Data Library (EXFOR). International Collaboration Between Nuclear Reaction Data Centres (NRDC)

    Energy Technology Data Exchange (ETDEWEB)

    Otuka, N.; Pritychenko, B.; Otuka, N.; Dupont, E.; Semkova, V.; Pritychenko, B.; Blokhin, A. I.; Aikawa, M.; Babykina, S.; Bossant, M.; Chen, G.; Dunaeva, S.; Forrest, R. A.; Fukahori, T.; Furutachi, N.; Ganesan, S.; Ge, Z.; Gritzay, O. O.; Herman, M.; Hlavac, S.; Kato, K.; Lalremruata, B.; Lee, Y. O.; Makinaga, A.; Matsumoto, K.; Mikhaylyukova, M.; Pikulina, G.; Pronyaev, V. G.; Saxena, A.; Schwerer, O.; Simakov, S. P.; Soppera, N.; Suzuki, R.; Takacs, S.; Tao, X.; Taova, S.; Tarkanyi, F.; Varlamov, V. V.; Wang, J.; Yang, S. C.; Zerkin, V.; Zhuang, Y.

    2014-06-01

    The International Network of Nuclear Reaction Data Centres (NRDC) coordinated by the IAEA Nuclear Data Section (NDS) successfully collaborates in the maintenance and development of the EXFOR library. Likewise, as the scope of published data expands (e.g. to higher energy, to heavier projectile) to meet the needs of research and applications, it has become a challenging task to maintain both the completeness and accuracy of the EXFOR library. Evolution of the library highlighting recent developments is described.

  3. Towards a More Complete and Accurate Experimental Nuclear Reaction Data Library (EXFOR): International Collaboration Between Nuclear Reaction Data Centres (NRDC)

    Energy Technology Data Exchange (ETDEWEB)

    Otuka, N., E-mail: n.otsuka@iaea.org [Nuclear Data Section (NDS), International Atomic Energy Agency, A-1400 Vienna (Austria); Dupont, E. [OECD Nuclear Energy Agency Data Bank (NEA DB), F-92130 Issy-les-Moulineaux (France); Semkova, V. [Nuclear Data Section (NDS), International Atomic Energy Agency, A-1400 Vienna (Austria); Pritychenko, B. [National Nuclear Data Center (NNDC), Brookhaven National Laboratory, Upton, NY 11973 (United States); Blokhin, A.I. [Nuclear Data Centre (CJD), Institute for Physics and Power Engineering, 249033 Obninsk (Russian Federation); Aikawa, M. [Nuclear Reaction Data Centre (JCPRG), Hokkaido University, Sapporo 060-0810 (Japan); Babykina, S. [Centre for Nuclear Structure and Reaction Data (CAJaD), Kurchatov Institute, 123182 Moscow (Russian Federation); Bossant, M. [OECD Nuclear Energy Agency Data Bank (NEA DB), F-92130 Issy-les-Moulineaux (France); Chen, G. [China Nuclear Data Centre (CNDC), China Institute of Atomic Energy, Beijing 102413 (China); Dunaeva, S. [Centre of Nuclear Physics Data (CNPD), All-Russian Research Institute of Experimental Physics (VNIIEF), 607190 Sarov (Russian Federation); Forrest, R.A. [Nuclear Data Section (NDS), International Atomic Energy Agency, A-1400 Vienna (Austria); Fukahori, T. [Nuclear Data Center, Japan Atomic Energy Agency (JAEA), Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Furutachi, N. [Nuclear Reaction Data Centre (JCPRG), Hokkaido University, Sapporo 060-0810 (Japan); Ganesan, S. [Bhabha Atomic Research Centre, Mumbai 400085 (India); Ge, Z. [China Nuclear Data Centre (CNDC), China Institute of Atomic Energy, Beijing 102413 (China); Gritzay, O.O. [Ukrainian Nuclear Data Centre (UkrNDC), Institute for Nuclear Research, 03680 Kiev (Ukraine); Herman, M. [National Nuclear Data Center (NNDC), Brookhaven National Laboratory, Upton, NY 11973 (United States); Hlavač, S. [Department of Nuclear Physics, Institute of Physics, Slovak Academy of Sciences, 845 11 Bratislava (Slovakia); and others

    2014-06-15

    The International Network of Nuclear Reaction Data Centres (NRDC) coordinated by the IAEA Nuclear Data Section (NDS) successfully collaborates in the maintenance and development of the EXFOR library. As the scope of published data expands (e.g. to higher energy, to heavier projectile) to meet the needs of research and applications, it has become a challenging task to maintain both the completeness and accuracy of the EXFOR library. Evolution of the library highlighting recent developments is described.

  4. Towards a More Complete and Accurate Experimental Nuclear Reaction Data Library (EXFOR): International Collaboration Between Nuclear Reaction Data Centres (NRDC)

    International Nuclear Information System (INIS)

    The International Network of Nuclear Reaction Data Centres (NRDC) coordinated by the IAEA Nuclear Data Section (NDS) successfully collaborates in the maintenance and development of the EXFOR library. As the scope of published data expands (e.g. to higher energy, to heavier projectile) to meet the needs of research and applications, it has become a challenging task to maintain both the completeness and accuracy of the EXFOR library. Evolution of the library highlighting recent developments is described

  5. Transformation of Symmetrization Order to Nuclear-Spin Magnetization by Chemical Reaction and Nuclear Magnetic Resonance

    OpenAIRE

    Bowers, C. Russell; Weitekamp, Daniel P.

    1986-01-01

    A method of obtaining very large nuclear-spin polarizations is proposed and illustrated by density-operator calculations. The prediction is that chemical reaction and rf irradiation can convert the scalar parahydrogen state into polarization of order unity on the nuclear spins of the products of molecular-hydrogen addition reactions. A means of extending the resultant sensitivity enhancement to other spins is proposed in which the transfer of order occurs through population differences not as...

  6. High energy gamma-ray production in nuclear reactions

    International Nuclear Information System (INIS)

    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

  7. Nuclear data needs for material analysis

    International Nuclear Information System (INIS)

    Nuclear data for material analysis using neutron-based methods are examined. Besides a critical review of the available data, emphasis is given to emerging application areas and new experimental techniques. Neutron scattering and reaction data, as well as decay data for delayed and prompt gamma activation analysis are all discussed in detail. Conclusions are formed concerning the need of new measurement, calculation, evaluation and dissemination activities. (author)

  8. Nuclear reaction effects in use of newly recommended quality factor

    Science.gov (United States)

    Shinn, Judy L.; Wilson, John W.

    1991-01-01

    The biological risk for energetic ion exposure cannot be reliably estimated exclusive of the target nuclear reaction products produced within the local tissue. A theoretical basis is derived for evaluating target fragment contributions that are evaluated for the newly proposed quality factor.

  9. Direct reactions involving pion production in hot nuclear matter

    Energy Technology Data Exchange (ETDEWEB)

    Voskresenskii, D.N.; Kolomeitsev, E.E. [Moscow Institute of Engineering Physics (Russian Federation)

    1995-01-01

    Probabilities and differential cross sections for the production of {pi}{sup {minus}} mesons in direct NN {yields} NN{pi}{sup {minus}lk} reactions are calculated with allowance for a change in the NN interaction in nuclear matter. The results are obtained in an analytic form for arbitrary temperatures of matter and arbitrary energies and momenta of pions. 13 refs.

  10. People's Reactions to Nuclear War: Implications for Psychologists.

    Science.gov (United States)

    Fiske, Susan T.

    1987-01-01

    Reviews available data documenting modal adults' beliefs, feelings, and actions regarding nuclear war. Examines discrepancies between peoples's beliefs and their relative lack of affective and behavioral response. Reviews data on possible psychological and social sources of those reactions. Contrasts average citizens, antinuclear activists, and…

  11. A Laboratory Experiment on the Statistical Theory of Nuclear Reactions

    Science.gov (United States)

    Loveland, Walter

    1971-01-01

    Describes an undergraduate laboratory experiment on the statistical theory of nuclear reactions. The experiment involves measuring the relative cross sections for formation of a nucleus in its meta stable excited state and its ground state by applying gamma-ray spectroscopy to an irradiated sample. Involves 3-4 hours of laboratory time plus…

  12. Nuclear reactions of high energy deuterons with medium mass targets

    International Nuclear Information System (INIS)

    Formation cross sections of product nuclides in the nuclear reactions of medium mass targets by 10 GeV deuterons were measured with a gamma-ray spectroscopy. The measured data were compared with the cross sections of 12 GeV protons. (author)

  13. A primer for electroweak induced low-energy nuclear reactions

    Indian Academy of Sciences (India)

    Y N Srivastava; A Widom; L Larsen

    2010-10-01

    Under special circumstances, electromagnetic and weak interactions can induce low-energy nuclear reactions to occur with observable rates for a variety of processes. A common element in all these applications is that the electromagnetic energy stored in many relatively slow-moving electrons can – under appropriate circumstances – be collectively transferred into fewer, much faster electrons with energies sufficient for the latter to combine with protons (or deuterons, if present) to produce neutrons via weak interactions. The produced neutrons can then initiate low-energy nuclear reactions through further nuclear transmutations. The aim of this paper is to extend and enlarge upon various examples analysed previously, present order of magnitude estimates for each and to illuminate a common unifying theme amongst all of them.

  14. Studies of 3He Induced Nuclear Reactions on Cadmium

    International Nuclear Information System (INIS)

    Excitation functions of 3He induced nuclear reactions on natural cadmium were measured using the standard stacked foil technique and high resolution gamma ray spectroscopy. The experimental cross sections for the nuclear reactions natCd(3He,xnp )117m,g,116m115m,114m,113m,111,110m,g,109,108,107 In were measured from their threshold energy up to 27 MeV. The integral yields for some medically important products were determined. Theoretical calculations using the nuclear codes ALICE- IPPE, TAL YS, and EMPIRE-3 were used to describe the formation of these products. Theoretical and experimental results were compared with each other. K

  15. Neutrino-induced Reactions and Neutrino Scattering with Nuclear Targets

    Science.gov (United States)

    Cheoun, Myung-Ki; Ha, Eunja; Yang, Ghil-Seok; Kim, Kyungsik; Kajino, T.

    2016-02-01

    We reviewed present status regarding experimental data and theoretical approaches for neutrino-induced reactions and neutrino scattering. With a short introduction of relevant data, our recent calculations by distorted-wave Born approximation for quasielastic region are presented for MiniBooNE data. For much higher energy neutrino data, such as NOMAD data, elementary process approach was shown to be useful instead of using complicated nuclear models. But, in the low energy region, detailed nuclear structure model, such as QRPA and shell model, turn out to be inescapable to explain the reaction data. Finally, we discussed that one step-process in the reaction is comparable to the two-step process, which has been usually used in the neutrino-nucleosynthesis.

  16. Neutrino-induced Reactions and Neutrino Scattering with Nuclear Targets

    Directory of Open Access Journals (Sweden)

    Cheoun Myung-Ki

    2016-01-01

    Full Text Available We reviewed present status regarding experimental data and theoretical approaches for neutrino-induced reactions and neutrino scattering. With a short introduction of relevant data, our recent calculations by distorted-wave Born approximation for quasielastic region are presented for MiniBooNE data. For much higher energy neutrino data, such as NOMAD data, elementary process approach was shown to be useful instead of using complicated nuclear models. But, in the low energy region, detailed nuclear structure model, such as QRPA and shell model, turn out to be inescapable to explain the reaction data. Finally, we discussed that one step-process in the reaction is comparable to the two-step process, which has been usually used in the neutrino-nucleosynthesis.

  17. Ranking the importance of nuclear reactions for activation and transmutation events

    CERN Document Server

    Arter, Wayne; Relton, Samuel D; Higham, Nicholas J

    2015-01-01

    Pathways-reduced analysis is one of the techniques used by the Fispact-II nuclear activation and transmutation software to study the sensitivity of the computed inventories to uncertainties in reaction cross-sections. Although deciding which pathways are most important is very helpful in for example determining which nuclear data would benefit from further refinement, pathways-reduced analysis need not necessarily define the most critical reaction, since one reaction may contribute to several different pathways. This work examines three different techniques for ranking reactions in their order of importance in determining the final inventory, viz. a pathways based metric (PBM), the direct method and one based on the Pearson correlation coefficient. Reasons why the PBM is to be preferred are presented.

  18. Third international workshop on compound nuclear reactions and related topics. Book of abstracts

    International Nuclear Information System (INIS)

    The conference was divided into the following sections: Fission; Surrogate reactions; Heavy ion reactions; Neutron-induced reactions; Gamma-ray strength functions; Nuclear astrophysics; Superheavy nuclei; Nuclear level density; Various nuclear reactions; Optical model simulations; and Pre-equilibrium. The publication contains 82 abstracts. (P.A.)

  19. Unified ab initio approaches to nuclear structure and reactions

    Science.gov (United States)

    Navrátil, Petr; Quaglioni, Sofia; Hupin, Guillaume; Romero-Redondo, Carolina; Calci, Angelo

    2016-05-01

    The description of nuclei starting from the constituent nucleons and the realistic interactions among them has been a long-standing goal in nuclear physics. In addition to the complex nature of the nuclear forces, with two-, three- and possibly higher many-nucleon components, one faces the quantum-mechanical many-nucleon problem governed by an interplay between bound and continuum states. In recent years, significant progress has been made in ab initio nuclear structure and reaction calculations based on input from QCD-employing Hamiltonians constructed within chiral effective field theory. After a brief overview of the field, we focus on ab initio many-body approaches—built upon the no-core shell model—that are capable of simultaneously describing both bound and scattering nuclear states, and present results for resonances in light nuclei, reactions important for astrophysics and fusion research. In particular, we review recent calculations of resonances in the 6He halo nucleus, of five- and six-nucleon scattering, and an investigation of the role of chiral three-nucleon interactions in the structure of 9Be. Further, we discuss applications to the 7Be {({{p}},γ )}8{{B}} radiative capture. Finally, we highlight our efforts to describe transfer reactions including the 3H{({{d}},{{n}})}4He fusion.

  20. Nuclear medium effects on pre-equilibrium nucleon emission reactions

    International Nuclear Information System (INIS)

    Nuclear medium modifies the free nucleon-nucleon interaction cross section. The modified value of the cross section has its own impact on the preequilibrium emission spectrum. Such effect increases or decreases the tendency on neutron emission in comparative with proton emission. Several model of the in-medium nucleon-nucleon interaction cross sections are used in the calculation of the neutron emission spectra for some proton induced reactions. Results showed that as the mass of the target nucleus increases, the nuclear medium produces lesser influence than it does for smaller mass nuclei.

  1. Sigma: Web Retrieval Interface for Nuclear Reaction Data

    Energy Technology Data Exchange (ETDEWEB)

    Pritychenko,B.; Sonzogni, A.A.

    2008-06-24

    The authors present Sigma, a Web-rich application which provides user-friendly access in processing and plotting of the evaluated and experimental nuclear reaction data stored in the ENDF-6 and EXFOR formats. The main interface includes browsing using a periodic table and a directory tree, basic and advanced search capabilities, interactive plots of cross sections, angular distributions and spectra, comparisons between evaluated and experimental data, computations between different cross section sets. Interactive energy-angle, neutron cross section uncertainties plots and visualization of covariance matrices are under development. Sigma is publicly available at the National Nuclear Data Center website at www.nndc.bnl.gov/sigma.

  2. Retrieval transmutation and decay process of nuclides using nuclear reaction database on internet

    International Nuclear Information System (INIS)

    In the data system for alloy design and selection of materials used in various nuclear reactors, huge material databases and several kinds of tools for data analysis or simulation code of the phenomena under neutron irradiation are required. A nuclear reaction database system based on the data of FENDL-II on the Internet has been developed in NRIM site of Data-Free-Way'. The user interface in this database was made for the retrieval of the necessary data and for the expression of the graph of the relation between the nuclear energy spectrum of neutron and neutron capture cross section. It is indicated that using the database, the possibility of chemical compositional change and radioactivity in a material caused by nuclear reactions can be easily retrieved, though the evaluation is qualitatively. (author)

  3. Importance of ORELA for Developing Nuclear Reaction Models

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, F S

    2005-12-08

    Because of its excellent energy resolution, ORELA is particularly well suited for measurements in the resolved resonance region that impact nuclear reaction model calculations. These measurements allow the determination of average level widths, level densities, and cross sections for potential scattering and radiative capture. These quantities can be used to determine parameters in reaction models (such as the optical model and Hauser-Feshbach calculations) and to understand the limitations imposed on these models. Particular attention is given to the importance of improved experimental data to characterize intermediate structure (or doorway states).

  4. BRUSLIB and NETGEN: the Brussels nuclear reaction rate library and nuclear network generator for astrophysics

    Science.gov (United States)

    Aikawa, M.; Arnould, M.; Goriely, S.; Jorissen, A.; Takahashi, K.

    2005-10-01

    Nuclear reaction rates are quantities of fundamental importance in astrophysics. Substantial efforts have been devoted in the last decades to measuring or calculating them. This paper presents a detailed description of the Brussels nuclear reaction rate library BRUSLIB and of the nuclear network generator NETGEN. BRUSLIB is made of two parts. The first one contains the 1999 NACRE compilation based on experimental data for 86 reactions with (mainly) stable targets up to Si. BRUSLIB provides an electronic link to the published, as well as to a large body of unpublished, NACRE data containing adopted rates, as well as lower and upper limits. The second part of BRUSLIB concerns nuclear reaction rate predictions to complement the experimentally-based rates. An electronic access is provided to tables of rates calculated within a statistical Hauser-Feshbach approximation, which limits the reliability of the rates to reactions producing compound nuclei with a high enough level density. These calculations make use of global and coherent microscopic nuclear models for the quantities entering the rate calculations. The use of such models makes the BRUSLIB rate library unique. A description of the Nuclear Network Generator NETGEN that complements the BRUSLIB package is also presented. NETGEN is a tool to generate nuclear reaction rates for temperature grids specified by the user. The information it provides can be used for a large variety of applications, including Big Bang nucleosynthesis, the energy generation and nucleosynthesis associated with the non-explosive and explosive hydrogen to silicon burning stages, or the synthesis of the heavy nuclides through the s-, α- and r-, rp- or p-processes.

  5. Nuclear Reactor Engineering Analysis Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Carlos Chavez-Mercado; Jaime B. Morales-Sandoval; Benjamin E. Zayas-Perez

    1998-12-31

    The Nuclear Reactor Engineering Analysis Laboratory (NREAL) is a sophisticated computer system with state-of-the-art analytical tools and technology for analysis of light water reactors. Multiple application software tools can be activated to carry out different analyses and studies such as nuclear fuel reload evaluation, safety operation margin measurement, transient and severe accident analysis, nuclear reactor instability, operator training, normal and emergency procedures optimization, and human factors engineering studies. An advanced graphic interface, driven through touch-sensitive screens, provides the means to interact with specialized software and nuclear codes. The interface allows the visualization and control of all observable variables in a nuclear power plant (NPP), as well as a selected set of nonobservable or not directly controllable variables from conventional control panels.

  6. Approximate penetration factors for nuclear reactions of astrophysical interest

    Science.gov (United States)

    Humblet, J.; Fowler, W. A.; Zimmerman, B. A.

    1987-01-01

    The ranges of validity of approximations of P(l), the penetration factor which appears in the parameterization of nuclear-reaction cross sections at low energies and is employed in the extrapolation of laboratory data to even lower energies of astrophysical interest, are investigated analytically. Consideration is given to the WKB approximation, P(l) at the energy of the total barrier, approximations derived from the asymptotic expansion of G(l) for large eta, approximations for small values of the parameter x, applications of P(l) to nuclear reactions, and the dependence of P(l) on channel radius. Numerical results are presented in tables and graphs, and parameter ranges where the danger of serious errors is high are identified.

  7. Exponential enhancement of nuclear reactions in condensed matter environment

    CERN Document Server

    Kuchiev, M Yu; Flambaum, V V

    2003-01-01

    A mechanism that uses the environment to enhance the probability of the nuclear reaction when a beam of accelerated nuclei collides with a target nucleus implanted in condensed matter is suggested. The effect considered is exponentially large for low collision energies. For t + p collision the mechanism becomes effective when the energy of the projectile tritium is below $\\sim$ 1 Kev per nucleon. The gain in probability of the nuclear reaction is due to a redistribution of energy and momentum of the projectile in several ``preliminary'' elastic collisions with the target nucleus and the environmental nuclei in such a way that the final inelastic projectile-target collision takes place at a larger relative velocity, which is accompanied by a decrease of the center of mass energy. The gain of the relative velocity exponentially increases the penetration through the Coulomb barrier.

  8. Coulomb and nuclear effects in breakup and reaction cross sections

    CERN Document Server

    Descouvemont, Pierre; Hussein, Mahir S

    2016-01-01

    We use a three-body Continuum Discretized Coupled Channel (CDCC) model to investigate Coulomb and nuclear effects in breakup and reaction cross sections. The breakup of the projectile is simulated by a finite number of square integrable wave functions. First we show that the scattering matrices can be split in a nuclear term, and in a Coulomb term. This decomposition is based on the Lippmann-Schwinger equation, and requires the scattering wave functions. We present two different methods to separate both effects. Then, we apply this separation to breakup and reaction cross sections of 7Li + 208Pb. For breakup, we investigate various aspects, such as the role of the alpha + t continuum, the angular-momentum distribution, and the balance between Coulomb and nuclear effects. We show that there is a large ambiguity in defining the 'Coulomb' and 'nuclear' breakup cross sections, since both techniques, although providing the same total breakup cross sections, strongly differ for the individual components. We suggest...

  9. Unified ab initio approaches to nuclear structure and reactions

    CERN Document Server

    Navratil, Petr; Hupin, Guillaume; Romero-Redondo, Carolina; Calci, Angelo

    2016-01-01

    The description of nuclei starting from the constituent nucleons and the realistic interactions among them has been a long-standing goal in nuclear physics. In addition to the complex nature of the nuclear forces, with two-, three- and possibly higher many-nucleon components, one faces the quantum-mechanical many-nucleon problem governed by an interplay between bound and continuum states. In recent years, significant progress has been made in {\\em ab initio} nuclear structure and reaction calculations based on input from QCD-employing Hamiltonians constructed within chiral effective field theory. After a brief overview of the field, we focus on ab initio many-body approaches - built upon the No-Core Shell Model - that are capable of simultaneously describing both bound and scattering nuclear states, and present results for resonances in light nuclei, reactions important for astrophysics and fusion research. In particular, we review recent calculations of resonances in the $^6$He halo nucleus, of five- and six...

  10. Analysis of Nuclear Reactions Used for the Synthesis of Heavy and Superheavy Elements in the Framework of the Dinuclear System Concept

    CERN Document Server

    Volkov, V V

    2003-01-01

    Reactions used for the synthesis of heavy and superheavy elements are analyzed within the framework of the dinuclear system concept. The important role of quasi- fission and the inner fusion potential barrier is emphasized. The results of calculation of the production cross sections for heavy and superheavy elements synthesized in cold and hot fusion reactions are given in comparison with experimental data. The minimum value of compound nucleus excitation energy is calculated for elements from 104 to 114, produced in cold fusion reactions. This article is a short survey of some results obtained by a group of physicists, using the dinuclear system concept.

  11. Measurement of anomalous nuclear reaction in deuterium-loaded metal

    Institute of Scientific and Technical Information of China (English)

    Jiang Song-Sheng; Li Jing-Huai; Wang Jian-Qing; He Ming; Wu Shao-Yong; Zhang Hong-Tao; Yao Shun-He; Zhao Yong-Gang

    2009-01-01

    This paper reports on an experiment for testing natural nuclear fusion at low temperature searching for evidence of the origin of 3He from natural nuclear fusion in deep Earth.The experiment was carried out using deuterium-loaded titanium foil samples and powder sample.Detection of charged particle was carried out using a low-level charged particle spectrometer.An Al foil was used as an energy absorber for identification of charged particle.Although the counting rate is very low in the experiment,the emission of energetic particle from the sample is obscrved and the particle is identified as a proton having energy about 2.8 MeV after exiting the titanium sample.This work provides a positive result for the emission of charged particle in the deuterium-loaded titanium foil samples at low temperature,but a negative result for the deuterium-loaded titanium powder sample.The average reaction yield is deduced to be(0.46±0.08)protons/h for the foil samples.With the suggestion that the proton originates from d-d reaction,we of the deuterium-loaded titanium powder sample suggests that the reaction yield might be correlated with the density or microscopic variables of deuterium-loaded titanium materials.The negative result also indicates that d-d reaction catalysed by μ-meson from cosmic ray can be excluded in the samples in this experiment.

  12. Low-energy nuclear reactions with double-solenoid- based radioactive nuclear beam

    Indian Academy of Sciences (India)

    Valdir Guimarães

    2010-07-01

    The University of Notre Dame, USA (Becchetti et al, Nucl. Instrum. Methods Res. A505, 377 (2003)) and later the University of São Paulo, Brazil (Lichtenthaler et al, Eur. Phys. J. A25, S-01, 733 (2005)) adopted a system based on superconducting solenoids to produce low-energy radioactive nuclear beams. In these systems the solenoids act as thick lenses to collect, select, and focus the secondary beam into a scattering chamber. Many experiments with radioactive light particle beams (RNB) such as 6He, 7Be, 8Li, 8B have been performed at these two facilities. These low-energy RNB have been used to investigate low-energy reactions such as elastic scattering, transfer and breakup, providing useful information on the structure of light nuclei near the drip line and on astrophysics. Total reaction cross-sections, derived from elastic scattering analysis, have also been investigated for light system as a function of energy and the role of breakup of weakly bound or exotic nuclei is discussed.

  13. Visualized kinematics code for two-body nuclear reactions

    Science.gov (United States)

    Lee, E. J.; Chae, K. Y.

    2016-05-01

    The one or few nucleon transfer reaction has been a great tool for investigating the single-particle properties of a nucleus. Both stable and exotic beams are utilized to study transfer reactions in normal and inverse kinematics, respectively. Because many energy levels of the heavy recoil from the two-body nuclear reaction can be populated by using a single beam energy, identifying each populated state, which is not often trivial owing to high level-density of the nucleus, is essential. For identification of the energy levels, a visualized kinematics code called VISKIN has been developed by utilizing the Java programming language. The development procedure, usage, and application of the VISKIN is reported.

  14. Mean-field instabilities and cluster formation in nuclear reactions

    CERN Document Server

    Colonna, M; Baran, V

    2016-01-01

    We review recent results on intermediate mass cluster production in heavy ion collisions at Fermi energy and in spallation reactions. Our studies are based on modern transport theories, employing effective interactions for the nuclear mean-field and incorporating two-body correlations and fluctuations. Namely we will consider the Stochastic Mean Field (SMF) approach and the recently developed Boltzmann-Langevin One Body (BLOB) model. We focus on cluster production emerging from the possible occurrence of low-density mean-field instabilities in heavy ion reactions. Within such a framework, the respective role of one and two-body effects, in the two models considered, will be carefully analysed. We will discuss, in particular, fragment production in central and semi-peripheral heavy ion collisions, which is the object of many recent experimental investigations. Moreover, in the context of spallation reactions, we will show how thermal expansion may trigger the development of mean-field instabilities, leading to...

  15. Supporting the Josephson Interpretation of Low Energy Nuclear Reactions and Stabilization of Nuclear Waste

    Directory of Open Access Journals (Sweden)

    F. Osman

    2005-01-01

    Full Text Available Brian Josephson appealed at the meeting of the Nobel Laureates July 2004 against the ignorance of physicist to the phenomenon of cold fusion. Though there are good reasons against many publications on this topic but not for all what was reported. It seems to be indicated to summarize the following serious, reproducible and confirmed observations on the reactions of protons or deuterons incorporated in host metals such as palladium, nickel and other metals. We underline the confusing discovery by Cockroft and Oliphant with the anomalous low energy for nuclear reactions which was hundred times lower than in the usual cases when smashing nuclei against their Coulomb potential. A similar unexpected result was that of Otto Hahn’s-the chemist!-Discovery of fission that had changed the world. A significant result of cold fusion was seen in gaseous atmosphere or discharges between palladium targets, rather significant and fully reproducible, e.g. From the “life after death” heat production of such high values per host atom that only nuclear reactions can be involved. This supports the earlier evaluation of neutron generation in fully reversible experiments with gas discharges hinting that a reasonable screening effect-preferably in the swimming electron layer-may lead to reactions at nuclear distances d of picometers with reaction probability times U off about mega seconds similar to the K-shell capture radioactivity. Further electrolytic experiments led to Low Energy Nuclear Reactions (LENR where the involvement of pollution could be excluded from the generation of very seldom rare earth elements. A basically new theory for DD cross sections is used to confirm the picometer-mega second reactions of cold fusion. Other theoretical aspects are given from measured heavy element distributions similar to the standard abundance distribution, SAD, in the Universe with consequences on endothermic heavy nucleus generation, magic numbers and to quark

  16. Rydberg phases of Hydrogen and low energy nuclear reactions

    Science.gov (United States)

    Olafsson, Sveinn; Holmlid, Leif

    2016-03-01

    For over the last 26 years the science of cold fusion/LENR has been researched around the world with slow pace of progress. Modest quantity of excess heat and signatures of nuclear transmutation and helium production have been confirmed in experiments and theoretical work has only resulted in a large flora of inadequate theoretical scenarios. Here we review current state of research in Rydberg matter of Hydrogen that is showing strong signature of nuclear processes. In the presentation experimental behavior of Rydberg matter of hydrogen is described. An extensive collaboration effort of surface physics, catalysis, atomic physics, solid state physics, nuclear physics and quantum information is need to tackle the surprising experimental results that have so far been obtained. Rydberg matter of Hydrogen is the only known state of matter that is able to bring huge collection of protons to so short distances and for so long time that tunneling becomes a reasonable process for making low energy nuclear reactions. Nuclear quantum entanglement can also become realistic process at theses conditions.

  17. VizieR Online Data Catalog: Brussels nuclear reaction rate library (Aikawa+, 2005)

    Science.gov (United States)

    Aikawa, M.; Arnould, M.; Goriely, S.; Jorissen, A.; Takahashi, K.

    2005-07-01

    The present data is part of the Brussels nuclear reaction rate library (BRUSLIB) for astrophysics applications and concerns nuclear reaction rate predictions calculated within the statistical Hauser-Feshbach approximation and making use of global and coherent microscopic nuclear models for the quantities (nuclear masses, nuclear structure properties, nuclear level densities, gamma-ray strength functions, optical potentials) entering the rate calculations. (4 data files).

  18. Dynamical calculations of nuclear fission and heavy-ion reactions

    International Nuclear Information System (INIS)

    With the goal of determining the magnitude and mechanism of nuclear dissipation from comparisons of predictions with experimental data, we describe recent calculations in a unified macroscopic-microscopic approach to large-amplitude collective nuclear motion such as occurs in fission and heavy-ion reactions. We describe the time dependence of the distribution function in phase space of collective coordinates and momenta by a generalized Fokker-Planck equation. The nuclear potential energy of deformation is calculated as the sum of repulsive Coulomb and centrifugal energies and an attractive Yukawa-plus-exponential potential, the inertia tensor is calculated for a superposition of rigid-body rotation and incompressible, nearly irrotational flow by use of the Werner-Wheeler method, and the dissipation ensor that describes the conversion of collective energy into single-particle excitation energy is calculated for two prototype mechanisms that represent opposite extremes of large and small dissipation. We solve the generalized Hamilton equations of motion for the first moments of the distribution function to obtain the mean translational fission-fragment kinetic energy and mass of a third fragment that sometimes forms between the two end fragments, as well as dynamical thresholds, capture cross sections, and ternary events in heavy-ion reactions. 33 references

  19. Microscopic Nuclear Structure and Reaction Calculations in the FMD Approach

    Science.gov (United States)

    Neff, T.; Feldmeier, H.; Langanke, K.

    We present here a first application of the Fermionic Molecular Dynamics (FMD) approach to low-energy nuclear reactions, namely the $^3$He($\\alpha$,$\\gamma$)$^7$Be radiative capture reaction. We divide the Hilbert space into an external region where the system is described as $^3$He and $^4$He clusters interacting only via the Coulomb interaction and an internal region where the nuclear interaction will polarize the clusters. Polarized configurations are obtained by a variation after parity and angular momentum projection procedure with respect to the parameters of all single particle states. A constraint on the radius of the intrinsic many-body state is employed to obtain polarized clusters at desired distances. The boundary conditions for bound and scattering states are implemented using the Bloch operator. The FMD calculations reproduce the correct energy for the centroid of the $3/2^-$ and $1/2^-$ bound states in $^7$Be. The charge radius of the ground state is in good agreement with recent experimental results. The FMD calculations also describe well the experimental phase shift data in the $1/2^+$, $3/2^+$ and $5/2^+$ channels that are important for the capture reaction at low energies. Using the bound and scattering many-body wave functions we calculate the radiative capture cross section. The calculated $S$ factor agrees very well, both in absolute normalization and energy dependence, with the recent experimental data from the Weizmann, LUNA, Seattle and ERNA experiments.

  20. Trojan Horse technique to measure nuclear astrophysics rearrangement reactions

    Science.gov (United States)

    Spitaleri, Claudio

    2013-03-01

    The knowledge of nucleosynthesis and of energy production in stars requires an increasingly precise measurement of nuclear fusion reactions at the Gamow energy. Because of the Coulomb barrier reaction cross sections in astrophysics cannot be accessed directly at ultra -low energies, unless very favorable conditions are met. Moreover, the energies characterizing nuclear processes in several astrophysical contexts are so low that the presence of atomic electrons must be taken into account. Theoretical extrapolations of available data are then needed to derive astrophysical S(E)-factors. To overcome these experimental difficulties the Trojan Horse Method (THM) has been introduced. The method provides a valid alternative path to measure unscreened low-energy cross sections of reactions between charged particles, and to retrieve information on the electron screening potential when ultra-low energy direct measurements are available. While the theory has been discussed in detail in some theoretical works, present in the scientific literature, also in relation to different types of excitation functions (e.g. non-resonant and resonant), work on detailed methodology used to extract the events to be considered for the bare nucleus cross section measurements is still on going. In this work we will present some critical points in the application of THM that deserve to be discussed in more detail.

  1. MSU SINP CDFE nuclear data activities in the nuclear reaction data centres network

    International Nuclear Information System (INIS)

    This paper is the progress report of the Centre for Photonuclear Experiments Data, Moscow. It is a short review of the works carried out by the CDFE concerning the IAEA nuclear reaction data centers network activities from May 2001 until May 2002. and the description of the main results obtained. (a.n.)

  2. Legendre Analysis of Hadronic Reactions

    CERN Document Server

    Azimov, Ya I

    2016-01-01

    Expansions over Legendre functions are suggested as a model-independent way of compact presentation of modern precise and high-statistics data for two-hadron reactions. Some properties of the expansions are described.

  3. Manual on usage of the Nuclear Reaction Data File (NRDF)

    International Nuclear Information System (INIS)

    In the computer in the Institute for Nuclear Study, University of Tokyo, there is set up a Nuclear Reaction Data File (NRDF) which has been built in Hokkaido University. While the data base is growing year after year, its trial usage is for the purpose of joint utilization by educational institutions. In section 1, examples of the retrieval are presented to have the user familiarize with NRDF. In section 2, the terms used in retrieval are given in table. Then, in section 3, as a summary of the examples, structure of the retrieval commands is explained. In section 4, for the retrieval results on a CRT, cautions in reading are given. Finally, in section 5, general cautions in usage of NRDF are given. (Mori, K.)

  4. Ab Initio Calculations Of Nuclear Reactions And Exotic Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Quaglioni, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-05-05

    Our ultimate goal is to develop a fundamental theory and efficient computational tools to describe dynamic processes between nuclei and to use such tools toward supporting several DOE milestones by: 1) performing predictive calculations of difficult-to-measure landmark reactions for nuclear astrophysics, such as those driving the neutrino signature of our sun; 2) improving our understanding of the structure of nuclei near the neutron drip line, which will be the focus of the DOE’s Facility for Rare Isotope Beams (FRIB) being constructed at Michigan State University; but also 3) helping to reveal the true nature of the nuclear force. Furthermore, these theoretical developments will support plasma diagnostic efforts at facilities dedicated to the development of terrestrial fusion energy.

  5. Ab Initio Calculations Of Nuclear Reactions And Exotic Nuclei

    International Nuclear Information System (INIS)

    Our ultimate goal is to develop a fundamental theory and efficient computational tools to describe dynamic processes between nuclei and to use such tools toward supporting several DOE milestones by: 1) performing predictive calculations of difficult-to-measure landmark reactions for nuclear astrophysics, such as those driving the neutrino signature of our sun; 2) improving our understanding of the structure of nuclei near the neutron drip line, which will be the focus of the DOE's Facility for Rare Isotope Beams (FRIB) being constructed at Michigan State University; but also 3) helping to reveal the true nature of the nuclear force. Furthermore, these theoretical developments will support plasma diagnostic efforts at facilities dedicated to the development of terrestrial fusion energy.

  6. One, two, infinity: A pragmatic approach to nuclear precompound reactions

    International Nuclear Information System (INIS)

    Single scattering dominates nucleon-nucleus inclusive cross sections for energies between 15 and 100 MeV. We prove this claim by formulating a multiple scattering expansion. It contains single, double and multiple collisions and converges very rapidly, so that triple and higher-order collisions can be treated as compound-nucleus formation and decay. The only imput parameter in the calculation is the mean free path, for which values between 3 and 5 fm are used. The approach predicts absolute values of inclusive cross sections dsigma/dΩdE for (p,p'), (n,n') and (p,n') reactions. Our approach fits experiments as well as other approaches. We analyse also new experiments. The transparency and simplicity of the approach and its success draw attention to some simple basic features in nuclear precompound reactions. (orig.)

  7. Theory of nuclear structure and reactions. Annual technical progress report, April 1, 1985-March 31, 1986

    International Nuclear Information System (INIS)

    In the period covered by this report (April 1, 1985 to March 31, 1986), work focused on five main areas: (A) relativistic effects in medium-energy nuclear reactions; (B) the role of quarks and gluons in nuclear physics; (C) quantum hadrodynamics and relativistic nuclear structure theory; (D) structure and reaction effects in intermediate-energy nuclear reactions; and (E) weak and electromagnetic interactions in nuclei. Results and publications in these areas are summarized

  8. Investigations of nuclear structure and nuclear reactions induced by complex projectiles

    International Nuclear Information System (INIS)

    The research program described touches five areas of nuclear physics: nuclear structure studies at high spin (hyperdeformation in the mass A ≅ 182 region, structure of 182Hg and 182Au at high spin, a highly deformed band in 136Pm and the anomalous h11/2 proton crossing in the A∼135 superdeformed region), studies at the interface between structure and reactions (population of entry states in heavy-ion fusion reactions, nuclear structure effects in proton evaporation spectra, nuclear structure- dependent entry state population by total spectroscopy, entrance channel effects in fusion near the barrier, lifetimes of subbarrier α particles by the atomic clock method), production and study of hot nuclei (the statistical model evaporation code EVAP, statistical emission of deuterons and tritons from highly excited compound nuclei, heavy-fragment emission as a probe of the thermal properties of highly excited compound nuclei, use of incoming-wave boundary condition transmission coefficients in the statistical model: implications in the particle evaporation spectra, study of transparency in the optical model), reaction mechanism studies (binary character of highly dissipative 209Bi + 136Xe collisions at E/A=28.2 MeV), and development and use of novel techniques and instrumentation in these areas of research (including a 4π channel selection device, a novel x-ray detector, and a simple channel-selecting detector)

  9. Economic analysis of nuclear energy

    International Nuclear Information System (INIS)

    This study identified the role of nuclear energy in the following three major aspects. First of all, this study carried out cost effectiveness of nuclear as a CDM technology, which is one of means of GHG emission reduction in UNFCCC. Secondly, environmental externalities caused by air pollutants emitted by power options were estimated. The 'observed market behaviour' method and 'responses to hypothetical market' method were used to estimate objectively the environmental external costs by electric source, respectively. Finally, the role of nuclear power in securing electricity supply in a liberalized electricity market was analyzed. This study made efforts to investigate whether nuclear power generation with high investment cost could be favored in a liberalized market by using 'option value' analysis of investments

  10. Economic analysis of nuclear energy

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ki Dong; Lee, M. K.; Moon, K. H.; Kim, S. S.; Lim, C. Y.; Kim, H. S

    2000-12-01

    This study identified the role of nuclear energy in the following three major aspects. First of all, this study carried out cost effectiveness of nuclear as a CDM technology, which is one of means of GHG emission reduction in UNFCCC. Secondly, environmental externalities caused by air pollutants emitted by power options were estimated. The 'observed market behaviour' method and 'responses to hypothetical market' method were used to estimate objectively the environmental external costs by electric source, respectively. Finally, the role of nuclear power in securing electricity supply in a liberalized electricity market was analyzed. This study made efforts to investigate whether nuclear power generation with high investment cost could be favored in a liberalized market by using 'option value' analysis of investments.

  11. Ab Initio Nuclear Structure and Reaction Calculations for Rare Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Draayer, Jerry P. [Louisiana State Univ., Baton Rouge, LA (United States)

    2014-09-28

    We have developed a novel ab initio symmetry-adapted no-core shell model (SA-NCSM), which has opened the intermediate-mass region for ab initio investigations, thereby providing an opportunity for first-principle symmetry-guided applications to nuclear structure and reactions for nuclear isotopes from the lightest p-shell systems to intermediate-mass nuclei. This includes short-lived proton-rich nuclei on the path of X-ray burst nucleosynthesis and rare neutron-rich isotopes to be produced by the Facility for Rare Isotope Beams (FRIB). We have provided ab initio descriptions of high accuracy for low-lying (including collectivity-driven) states of isotopes of Li, He, Be, C, O, Ne, Mg, Al, and Si, and studied related strong- and weak-interaction driven reactions that are important, in astrophysics, for further understanding stellar evolution, X-ray bursts and triggering of s, p, and rp processes, and in applied physics, for electron and neutrino-nucleus scattering experiments as well as for fusion ignition at the National Ignition Facility (NIF).

  12. Microscopic Nuclear Structure and Reaction Calculations in the FMD Approach

    CERN Document Server

    Neff, Thomas; Langanke, Karlheinz

    2010-01-01

    We present here a first application of the Fermionic Molecular Dynamics (FMD) approach to low-energy nuclear reactions, namely the $^3$He($\\alpha$,$\\gamma$)$^7$Be radiative capture reaction. We divide the Hilbert space into an external region where the system is described as $^3$He and $^4$He clusters interacting only via the Coulomb interaction and an internal region where the nuclear interaction will polarize the clusters. Polarized configurations are obtained by a variation after parity and angular momentum projection procedure with respect to the parameters of all single particle states. A constraint on the radius of the intrinsic many-body state is employed to obtain polarized clusters at desired distances. The boundary conditions for bound and scattering states are implemented using the Bloch operator. The FMD calculations reproduce the correct energy for the centroid of the $3/2^-$ and $1/2^-$ bound states in $^7$Be. The charge radius of the ground state is in good agreement with recent experimental re...

  13. On microscopic theory of radiative nuclear reaction characteristics

    CERN Document Server

    Kamerdzhiev, Sergei; Avdeenkov, Alexander; Goriely, Stephane

    2015-01-01

    A survey of some results in the modern microscopic theory of properties of nuclear reactions with gamma-rays is given. First of all, we discuss the impact of phonon coupling (PC) on the photon strength function (PSF) because it represents the most natural physical source of additional strength found for Sn isotopes in recent experiments that could not be explained within the stan- dard HFB+QRPA approach. The self-consistent version of the Extended Theory of Finite Fermi Systems in the Quasiparticle Time Blocking Approximation, or simply QTBA, is applied. It uses the HFB mean field and includes both the QRPA and PC effects on the basis of the SLy4 Skyrme force. With our microscopic E1 PSFs, the following properties have been calculated for many stable and unstable even-even semi-magic Sn and Ni isotopes as well as for double-magic 132Sn and 208Pb using the reaction codes EMPIRE and TALYS with several nuclear level density (NLD) models: 1) the neutron capture cross sections, 2) the corresponding neutron capture...

  14. Probing the Nuclear Symmetry Energy with Heavy-Ion Reactions Induced by Neutron-Rich Nuclei

    OpenAIRE

    Chen, Lie-Wen; Ko, Che Ming; Li, Bao-An; Yong, Gao-Chan

    2007-01-01

    Heavy-ion reactions induced by neutron-rich nuclei provide a unique means to investigate the equation of state of isospin-asymmetric nuclear matter, especially the density dependence of the nuclear symmetry energy. In particular, recent analyses of the isospin diffusion data in heavy-ion reactions have already put a stringent constraint on the nuclear symmetry energy around the nuclear matter saturation density. We review this exciting result and discuss its implications on nuclear effective ...

  15. Modelling of the spallation reaction: analysis and testing of nuclear models; Simulation de la spallation: analyse et test des modeles nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Toccoli, C

    2000-04-03

    The spallation reaction is considered as a 2-step process. First a very quick stage (10{sup -22}, 10{sup -29} s) which corresponds to the individual interaction between the incident projectile and nucleons, this interaction is followed by a series of nucleon-nucleon collisions (intranuclear cascade) during which fast particles are emitted, the nucleus is left in a strongly excited level. Secondly a slower stage (10{sup -18}, 10{sup -19} s) during which the nucleus is expected to de-excite completely. This de-excitation is performed by evaporation of light particles (n, p, d, t, {sup 3}He, {sup 4}He) or/and fission or/and fragmentation. The HETC code has been designed to simulate spallation reactions, this simulation is based on the 2-steps process and on several models of intranuclear cascades (Bertini model, Cugnon model, Helder Duarte model), the evaporation model relies on the statistical theory of Weiskopf-Ewing. The purpose of this work is to evaluate the ability of the HETC code to predict experimental results. A methodology about the comparison of relevant experimental data with results of calculation is presented and a preliminary estimation of the systematic error of the HETC code is proposed. The main problem of cascade models originates in the difficulty of simulating inelastic nucleon-nucleon collisions, the emission of pions is over-estimated and corresponding differential spectra are badly reproduced. The inaccuracy of cascade models has a great impact to determine the excited level of the nucleus at the end of the first step and indirectly on the distribution of final residual nuclei. The test of the evaporation model has shown that the emission of high energy light particles is under-estimated. (A.C.)

  16. Isospin dynamics on neck fragmentation in isotopic nuclear reactions

    CERN Document Server

    Feng, Zhao-Qing

    2016-01-01

    The neck dynamics in Fermi-energy heavy-ion collisions, to probe the nuclear symmetry energy in the domain of sub-saturation densities, is investigated within an isospin dependent transport model. The single and double ratios of neutron/proton from free nucleons and light clusters (complex particles) in the isotopic reactions are analyzed systematically. Isospin effects of particles produced from the neck fragmentations are explored, which are constrained within the midrapidities ($|y/y_{proj}|<$0.3) and azimuthal angles (70$^{o}\\sim$110$^{o}$, 250$^{o}\\sim$290$^{o}$) in semiperipheral nuclear collisions. It is found that the ratios of the energetic isospin particles strongly depend on the stiffness of nuclear symmetry energy and the effects increase with softening the symmetry energy, which would be a nice probe for extracting the symmetry energy below the normal density in experimentally. A flat structure appears at the tail spectra from the double ratio distributions. The neutron to proton ratio of ligh...

  17. Redox reaction and foaming in nuclear waste glass melting

    International Nuclear Information System (INIS)

    This document was prepared by Pacific Northwest Laboratory (PNL) and is an attempt to analyze and estimate the effects of feed composition variables and reducing agent variables on the expected chemistry of reactions occurring in the cold cap and in the glass melt in the nuclear waste glass Slurry-fed, joule-heated melters as they might affect foaming during the glass-making process. Numerous redox reactions of waste glass components and potential feed additives, and the effects of other feed variables on these reactions are reviewed with regard to their potential effect on glass foaming. A major emphasis of this report is to examine the potential positive or negative aspects of adjusting feed with formic acid as opposed to other feed modification techniques including but not limited to use of other reducing agents. Feed modification techniques other than the use of reductants that should influence foaming behavior include control of glass melter feed pH through use of nitric acid. They also include partial replacement of sodium salts by lithium salts. This latter action (b) apparently lowers glass viscosity and raises surface tension. This replacement should decrease foaming by decreasing foam stability

  18. Redox reaction and foaming in nuclear waste glass melting

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, J.L.

    1995-08-01

    This document was prepared by Pacific Northwest Laboratory (PNL) and is an attempt to analyze and estimate the effects of feed composition variables and reducing agent variables on the expected chemistry of reactions occurring in the cold cap and in the glass melt in the nuclear waste glass Slurry-fed, joule-heated melters as they might affect foaming during the glass-making process. Numerous redox reactions of waste glass components and potential feed additives, and the effects of other feed variables on these reactions are reviewed with regard to their potential effect on glass foaming. A major emphasis of this report is to examine the potential positive or negative aspects of adjusting feed with formic acid as opposed to other feed modification techniques including but not limited to use of other reducing agents. Feed modification techniques other than the use of reductants that should influence foaming behavior include control of glass melter feed pH through use of nitric acid. They also include partial replacement of sodium salts by lithium salts. This latter action (b) apparently lowers glass viscosity and raises surface tension. This replacement should decrease foaming by decreasing foam stability.

  19. Probing anharmonic properties of nuclear surface vibration by heavy-ion fusion reactions

    OpenAIRE

    Takigawa, N.; Hagino, K.; Kuyucak, S

    1997-01-01

    Describing fusion reactions between ^{16}O and ^{154}Dy and, between ^{16}O and ^{144}Sm by the $sd-$ and $sdf-$ interacting boson model, we show that heavy-ion fusion reactions are strongly affected by anharmonic properties of nuclear surface vibrations and nuclear shape, and thus provide a powerful method to study details of nuclear structure and dynamics.

  20. Vision of nuclear physics with photo-nuclear reactions by laser-driven gamma beams

    Energy Technology Data Exchange (ETDEWEB)

    Habs, D.; Tajima, T.; Schreiber, J.; Thirolf, P.G. [Munchen Ludwig-Maximilians-Univ., Faculty of Physics, Garching (Germany); Habs, D. [Max-Planck Institute of Quantum Optics, Garching (Germany); Fujiwara, M. [Osaka Univ., Research Center Nuclear Physics (Japan); Barty, C.P.J. [Lawrence Livermore National Laboratory, National Ignition Facility, Livermore CA (United States)

    2009-11-15

    A laser-accelerated dense electron sheet with an energy E equals gammamc{sup 2} can be used as a relativistic mirror to coherently reflect a second laser with photon energy Planck constantomega, thus generating by the Doppler brilliant high-energy photon beams with Planck constant equals 4gamma{sup 2}Planck constantomega and short duration for many new nuclear physics experiments. While the shortest-lived atomic levels are in the atto-second range, nuclear levels can have lifetimes down to zepto-seconds. We discuss how the modulation of electron energies in phase-locked laser fields used for as-measurements can be carried over to the new direct measurement of fs-zs nuclear lifetimes by modulating the energies of accompanying conversion electrons or emitted protons. In the field of nuclear spectroscopy we discuss the new perspective as a function of increasing photon energy. In nuclear systems a much higher sensitivity is predicted to the time variation of fundamental constants compared to atomic systems. For energies up to 50 keV Moessbauer-like recoilless absorption allows to produce nuclear bosonic ensembles with many delocalized coherent polaritons for the first time. Using the (gamma,n) reaction to produce cold, polarized neutrons with a focusing ellipsoidal device, brilliant cold polarized micro-neutron beams become available. The compact and relatively cheap laser-generated gamma beams may serve for extended studies at university-based facilities. (authors)

  1. GRAPE, System for Pre-compound and Compound Nuclear Reactions

    International Nuclear Information System (INIS)

    1 - Description of program or function: The GRAPE code system for the calculation of pre-compound and compound nuclear reactions. The main code in this system is GRYPHON. The statistical exciton model following the master-equation approach has been improved and extended for application as an evaluation tool of double- differential reaction cross sections at incident nucleon energies of 5 to 50 MeV. For this purpose the code system GRAPE has been developed, which combines a number of interesting features such as: unified treatment of pre-equilibrium and equilibrium processes, renormalized exciton state-densities summing up to the back-shifted Fermi-gas formula, a new model for the internal transition rates based upon the nucleon mean free path in nuclear matter, angle-energy distributions based on intra-nuclear scattering in nuclear matter, account of discrete-level excitations, a new model for gamma-ray competition, inclusion of multi-particle emission, and various sorting options with code output in the new ENDF-VI format. An important characteristic of the proposed model is that consistency with equilibrium models has been demanded for the summed exciton-state densities as well as for the particle and gamma-ray emission cross sections. Consistency with the adopted state densities has also been imposed upon the internal transition rates. A survey of the theory is given and structure of the GRYPHON code is described. This report also contains a user' manual for GRYPHON. 2 - Method of solution: The master equations are solved with a fast algorithm, without approximations. 3 - Restrictions on the complexity of the problem: - exciton model without spin-parity conservation; - incoming or outgoing particles: a, p, alpha, 3He, d, t, and gamma-rays; - the code has been tested for incoming neutrons only; - not more than 5 multi-particle emissions; - not more than 100 energy points (variable grid); - no calculation of full gamma-ray cascade; - maximum energy of composite

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

    International Nuclear Information System (INIS)

    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)

  3. {sup 14}N depth profiles in Ti and Ti6Al4V nitrided by various methods, measured by nuclear reaction analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vickridge, I.; Trompetter, B. [Institute of Geological and Nuclear Sciences Ltd., Lower Hutt (New Zealand); Brown, I. [Industrial Research Ltd, Lower Hutt (New Zealand)

    1993-12-31

    Titanium alloys have desirable mechanical properties for applications in many areas, but their surface properties, such as friction coefficient, hardness, and wear and corrosion resistance often need to be enhanced. This may be accomplished by forming a thin layer of titanium nitride on the surface, by such methods as thermal nitriding, Ion Beam Assisted Deposition (IBAD), sol-gel technology, or ion implantation. Ion Beam Analysis is assuming an increasing importance for characterising the composition of the outer few microns since it is the only technique that can rapidly yield quantitative concentration depth profiles of {sup 14}N with minimal disruption of the analysed region. 8 refs., 7 figs.

  4. Excitation Functions of Deuteron Induced Nuclear Reactions on Iron

    International Nuclear Information System (INIS)

    The excitation functions were measured for nuclear reactions induced by deuterons on natural iron leading to the production of 52g,54Mn and 55,56,57,58gCo radionuclides in the energy range from threshold energy up to 10 MeV. The measured data were compared with other measured data and also with the results of theoretical calculations using the default parameters of the codes EMPIRE-3.0 and TALYS. The coulomb barrier Bc for iron target was calculated and the excitation curves were discussed taking in consideration the deuteron breakup and the pre-equilibrium emission processes. The integral yields of 55,56,57,58gCO radionuclides were calculated as a function of deuteron energy

  5. Impact of phonon coupling on the radiative nuclear reaction characteristics

    CERN Document Server

    Achakovskiy, Oleg; Kamerdzhiev, Sergei

    2015-01-01

    The pygmy dipole resonance and photon strength functions (PSF) in stable and unstable Ni and Sn isotopes are calculated within the microscopic self-consistent version of the extended theory of finite fermi systems in the quasiparticle time blocking approximation. The approach includes phonon coupling (PC) effects in addition to the standard QRPA approach. The Skyrme force SLy4 is used. A pygmy dipole resonance in 72Ni is predicted at the mean energy of 12.4 MeV exhausting 25.7% of the total energy-weighted sum rule. With our microscopic E1 PSFs in the EMPIRE 3.1 code, the following radiative nuclear reaction characteristics have been calculated for several stable and unstable even-even Sn and Ni isotopes: 1) neutron capture cross sections, 2) corresponding neutron capture gamma-spectra, 3) average radiative widths of neutron resonances. Here, three variants of the microscopic nuclear level density models have been used and a comparison with the phenomenological generalized superfluid model (GSM) has been perf...

  6. Nuclear reactions with radioactive and stable beams (Part I)

    International Nuclear Information System (INIS)

    At the present time there is a great interest at world level in experiments, with accelerated nuclei of short half life. The dispersion, fusion, transfer and break processes in the interaction of weakly light projectiles bounded with targets of Z great its have been object of intense recent investigation, at world level. Our group, in collaboration with the University of Notre Dame, it has measured and analyzed these processes for weakly bound systems as: 6He + 209Bi, 8Li + 208Pb, 10Be + 208Pb. On the other hand a research line that has wakened up great interest, it is that of studies of resonant reactions using the Inverse Kinematics technique with thick targets. The use of this technique allows to measure an entire excitation function with a single bombardment. Our group has carried out, in the ININ, preliminary bombardments for the system 12C + 4He. This allowed to establish the feasibility of implementing this technique in our Laboratory. The application of this and other techniques to different systems like 18O + 4He, 12C + 12C, 12C + 16O, 16O + 16O, it opens the possibility to measure the fusion of these systems at very low energy and to deepen in the knowledge of the nuclear structure and the nuclear astrophysics. In this technical report, the activities carried out by our group during 2004 are described.(Author)

  7. Impact of phonon coupling on the radiative nuclear reaction characteristics

    Directory of Open Access Journals (Sweden)

    Achakovskiy Oleg

    2016-01-01

    Full Text Available The pygmy dipole resonance and photon strength functions (PSF in stable and unstable Ni and Sn isotopes are calculated within the microscopic self-consistent version of the extended theory of finite Fermi systems in the quasiparticle time blocking approximation. The approach includes phonon coupling (PC effects in addition to the standard QRPA approach. The Skyrme force SLy4 is used. A pygmy dipole resonance in 72Ni is predicted at the mean energy of 12.4 MeV exhausting 25.7% of the total energy-weighted sum rule. With our microscopic E1 PSFs in the EMPIRE 3.1 code, the following radiative nuclear reaction characteristics have been calculated for several stable and unstable even-even Sn and Ni isotopes: 1 neutron capture cross sections, 2 corresponding neutron capture gamma-spectra, 3 average radiative widths of neutron resonances. Here, three variants of the microscopic nuclear level density models have been used and a comparison with the phenomenological generalized superfluid model has been performed. In all the considered properties, including the recent experimental data for PSF in Sn isotopes, the PC contributions turned out to be significant, as compared with the QRPA one, and necessary to explain the available experimental data.

  8. The nuclear fusion reaction rate based on relativistic equilibrium velocity distribution

    OpenAIRE

    Liu, Jian-Miin

    2002-01-01

    The Coulomb barrier is in general much higher than thermal energy. Nuclear fusion reactions occur only among few protons and nuclei with higher relative energies than Coulomb barrier. It is the equilibrium velocity distribution of these high-energy protons and nuclei that participates in determining the rate of nuclear fusion reactions. In the circumstance it is inappropriate to use the Maxwellian velocity distribution for calculating the nuclear fusion reaction rate. We use the relativistic ...

  9. Nuclear reactions with 14 MeV neutrons and bremsstrahlungs in giant dipole resonance (GDR) region using small accelerators

    Science.gov (United States)

    Thiep, Tran Duc; Van Do, Nguyen; An, Truong Thi; Son, Nguyen Ngoc

    2003-07-01

    In 1974 an accelerator of deterium, namely neutron generator NA-3-C was put into operation and in 1982 another accelerator of electron Microtron MT-17 started its work in the Institute of Physics. Though very modest these accelerators are useful for developing countries as Vietnam in both Nuclear Physics Research and Training. In this report we present some results obtained in studies on Nuclear Data, Nuclear Reactions as well as nuclear activation analysis methods. We also would like to discuss about the possibilities of collaboration in the future.

  10. Computer subroutines for the estimation of nuclear reaction effects in proton-tissue-dose calculations

    Science.gov (United States)

    Wilson, J. W.; Khandelwal, G. S.

    1976-01-01

    Calculational methods for estimation of dose from external proton exposure of arbitrary convex bodies are briefly reviewed. All the necessary information for the estimation of dose in soft tissue is presented. Special emphasis is placed on retaining the effects of nuclear reaction, especially in relation to the dose equivalent. Computer subroutines to evaluate all of the relevant functions are discussed. Nuclear reaction contributions for standard space radiations are in most cases found to be significant. Many of the existing computer programs for estimating dose in which nuclear reaction effects are neglected can be readily converted to include nuclear reaction effects by use of the subroutines described herein.

  11. The nuclear reaction n + 3He -> 1H + 3H as proximity reaction

    International Nuclear Information System (INIS)

    The present thesis tries to give by means of the nuclear reaction n + 3He -> 1H + 3H as proximity reaction on the three-particle system 3He + 9Be -> 1H + 3H + 8Be an experimental verification to the second term of a multiple scattering series. The study of these rescattering effects is of great interest for the present theory of the final-state interaction. At three incident energies (7.08 MeV, 8.98 MeV, and 6.37 MeV) to detector telescopes identify the exit channel of the three-particle system in list-mode coincidence experiments according to protons and tritons. Peaks on the kinematical curves occur. The detailed study of their kinematic behaviour allows to exclude the inconcurrence to the proximity reaction lying cascade decays via intermediate states in 4He, 9B, and 11B. Regarding the Coulomb interaction the experimental results can be also explained in the sense of the classical kinematics by the proximity model. (orig.)

  12. Studying nuclear level densities of {sup 238}U in the nuclear reactions within the macroscopic nuclear models

    Energy Technology Data Exchange (ETDEWEB)

    Razavi, Rohallah; Aghajani, Maghsood; Khooy, Asghar [Imam Hossein Comprehensive Univ., Tehran (Iran, Islamic Republic of). Dept. of Physics; Rahmatinejad, Azam; Taheri, Fariba [Univ. of Zanjan (Iran, Islamic Republic of). Dept. of Physics; Kakavand, Tayeb [Imam Khomeini International Univ., Qazvin (Iran, Islamic Republic of). Dept. of Physics

    2016-05-01

    In this work the nuclear level density parameters of {sup 238}U have been extracted in the back-shifted Fermi gas model (BSFGM), as well as the constant temperature model (CTM), through fitting with the recent experimental data on nuclear level densities measured by the Oslo group. The excitation functions for {sup 238}U(p,2nα){sup 233}Pa, and {sup 238}U(p,4n){sup 235}Np reactions and the fragment yields for the fragments of the {sup 238}U(p,f) reaction have been calculated using obtained level density parameters. The results are compared to their corresponding experimental values. It was found that the extracted excitation functions and the fragment yields in the CTM coincide well with the experimental values in the low-energy region. This finding is according to the claim made by the Oslo group that the extracted level densities of {sup 238}U show a constant temperature behaviour.

  13. The US nuclear reaction data network. Summary of the first meeting, March 13 & 14 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    The first meeting of the US Nuclear Reaction Data Network (USNRDN) was held at the Colorado School of Mines, March 13-14, 1996 chaired by F. Edward Cecil. The Agenda of the meeting is attached. The Network, its mission, products and services; related nuclear data and data networks, members, and organization are described in Attachment 1. The following progress reports from the members of the USNRDN were distributed prior to the meeting and are given as Attachment 2. (1) Measurements and Development of Analytic Techniques for Basic Nuclear Physics and Nuclear Applications; (2) Nuclear Reaction Data Activities at the National Nuclear Data Center; (3) Studies of nuclear reactions at very low energies; (4) Nuclear Reaction Data Activities, Nuclear Data Group; (5) Progress in Neutron Physics at Los Alamos - Experiments; (6) Nuclear Reaction Data Activities in Group T2; (7) Progress Report for the US Nuclear Reaction Data Network Meeting; (8) Nuclear Astrophysics Research Group (ORNL); (9) Progress Report from Ohio University; (10) Exciton Model Phenomenology; and (11) Progress Report for Coordination Meeting USNRDN.

  14. The US nuclear reaction data network. Summary of the first meeting, March 13 ampersand 14 1996

    International Nuclear Information System (INIS)

    The first meeting of the US Nuclear Reaction Data Network (USNRDN) was held at the Colorado School of Mines, March 13-14, 1996 chaired by F. Edward Cecil. The Agenda of the meeting is attached. The Network, its mission, products and services; related nuclear data and data networks, members, and organization are described in Attachment 1. The following progress reports from the members of the USNRDN were distributed prior to the meeting and are given as Attachment 2. (1) Measurements and Development of Analytic Techniques for Basic Nuclear Physics and Nuclear Applications; (2) Nuclear Reaction Data Activities at the National Nuclear Data Center; (3) Studies of nuclear reactions at very low energies; (4) Nuclear Reaction Data Activities, Nuclear Data Group; (5) Progress in Neutron Physics at Los Alamos - Experiments; (6) Nuclear Reaction Data Activities in Group T2; (7) Progress Report for the US Nuclear Reaction Data Network Meeting; (8) Nuclear Astrophysics Research Group (ORNL); (9) Progress Report from Ohio University; (10) Exciton Model Phenomenology; and (11) Progress Report for Coordination Meeting USNRDN

  15. Nuclear Parton Distributions and the Drell-Yan Reaction

    OpenAIRE

    S. A. Kulagin(INR, Moscow); Petti, R.

    2015-01-01

    We discuss the nuclear parton distribution functions on the basis of our recently developed semi-microscopic model, which takes into account a number of nuclear effects including Fermi motion and nuclear binding, nuclear meson-exchange currents and off-shell corrections to bound nucleon distributions as well as nuclear shadowing effect. We also discuss application to the nuclear Drell-Yan process and compare our predictions with data from the E772 and E866 experiments.

  16. Nuclear Futures Analysis and Scenario Building

    International Nuclear Information System (INIS)

    This LDRD project created and used advanced analysis capabilities to postulate scenarios and identify issues, externalities, and technologies associated with future ''things nuclear''. ''Things nuclear'' include areas pertaining to nuclear weapons, nuclear materials, and nuclear energy, examined in the context of future domestic and international environments. Analysis tools development included adaptation and expansion of energy, environmental, and economics (E3) models to incorporate a robust description of the nuclear fuel cycle (both current and future technology pathways), creation of a beginning proliferation risk model (coupled to the (E3) model), and extension of traditional first strike stability models to conditions expected to exist in the future (smaller force sizes, multipolar engagement environments, inclusion of actual and latent nuclear weapons (capability)). Accomplishments include scenario development for regional and global nuclear energy, the creation of a beginning nuclear architecture designed to improve the proliferation resistance and environmental performance of the nuclear fuel cycle, and numerous results for future nuclear weapons scenarios

  17. A study of heavy-heavy nuclear reactions. [nuclear research/nuclear particles

    Science.gov (United States)

    Khandelwal, G. S.

    1975-01-01

    Calculations are presented for the reaction products in high energy collisions and of the atmospheric transport of particles such as protons, neutrons and other nucleons. The magnetic moments of charmed baryons are examined. Total cross sections which are required for cosmic heavy ion transport and shielding studies are also examined.

  18. Vision of nuclear physics with photo-nuclear reactions by laser-driven γ beams

    Science.gov (United States)

    Habs, D.; Tajima, T.; Schreiber, J.; Barty, C. P. J.; Fujiwara, M.; Thirolf, P. G.

    2009-11-01

    A laser-accelerated dense electron sheet with an energy E=tilde{γ} mc^2 can be used as a relativistic mirror to coherently reflect a second laser with photon energy ħω, thus generating by the Doppler boost [A. Einstein, Annalen der Physik 17, 891 (1905); D. Habs et al., Appl. Phys. B 93, 349 (2008)] brilliant high-energy photon beams with hbarω^'=4tilde{γ}^2hbarω and short duration for many new nuclear physics experiments. While the shortest-lived atomic levels are in the atto-second range, nuclear levels can have lifetimes down to zeptoseconds. We discuss how the modulation of electron energies in phase-locked laser fields used for as-measurements [E. Goulielmakis et al., Science 317, 769 (2007)] can be carried over to the new direct measurement of fs-zs nuclear lifetimes by modulating the energies of accompanying conversion electrons or emitted protons. In the field of nuclear spectroscopy we discuss the new perspective as a function of increasing photon energy. In nuclear systems a much higher sensitivity is predicted to the time variation of fundamental constants compared to atomic systems [V. Flambaum, arXiv:nucl-th/0801.1994v1 (2008)]. For energies up to 50 keV Mössbauer-like recoilless absorption allows to produce nuclear bosonic ensembles with many delocalized coherent polaritons [G.V. Smirnov et al., Phys. Rev. A 71, 023804 (2005)] for the first time. Using the ( γ, n) reaction to produce cold, polarized neutrons with a focusing ellipsoidal device [P. Böni, Nucl. Instrum. Meth. A 586, 1 (2008); Ch. Schanzer et al., Nucl. Instrum. Meth. 529, 63 (2004)], brilliant cold polarized micro-neutron beams become available. The compact and relatively cheap laser-generated γ beams may serve for extended studies at university-based facilities.

  19. Compilation status and research topics in Hokkaido University nuclear reaction data centre

    International Nuclear Information System (INIS)

    The Hokkaido University Nuclear Reaction Data Centre (JCPRG) is a member of the International Network of Nuclear Reaction Data Centres (NRDC) under the auspices of the International Atomic Energy Agency (IAEA). JCPRG contributes about 10 percent of the data on charged-particle nuclear reactions in the EXFOR. In addition to the worldwide collaboration of compilation, Asian collaboration on compilation and evaluation was also promoted. As a result of this promotion, a research on the 9Be+n reaction was launched between Hokkaido University and Al-Farabi Kazakh National University. Beryllium is one of essential materials as a target window and a reflector for a spallation neutron source. The theoretical study and evaluation of the 9Be+n reaction are indispensable for nuclear engineering. We report current status of our activity and collaboration on compilation and evaluation of nuclear reaction data. (author)

  20. Laser-initiated primary and secondary nuclear reactions in Boron-Nitride

    Science.gov (United States)

    Labaune, C.; Baccou, C.; Yahia, V.; Neuville, C.; Rafelski, J.

    2016-02-01

    Nuclear reactions initiated by laser-accelerated particle beams are a promising new approach to many applications, from medical radioisotopes to aneutronic energy production. We present results demonstrating the occurrence of secondary nuclear reactions, initiated by the primary nuclear reaction products, using multicomponent targets composed of either natural boron (B) or natural boron nitride (BN). The primary proton-boron reaction (p + 11B → 3 α + 8.7 MeV), is one of the most attractive aneutronic fusion reaction. We report radioactive decay signatures in targets irradiated at the Elfie laser facility by laser-accelerated particle beams which we interpret as due to secondary reactions induced by alpha (α) particles produced in the primary reactions. Use of a second nanosecond laser beam, adequately synchronized with the short laser pulse to produce a plasma target, further enhanced the reaction rates. High rates and chains of reactions are essential for most applications.

  1. A study on nuclear specific material detection technique using nuclear resonance reactions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y. K.; Ha, J. H.; Cho, Y. S.; Choi, B. H. [KAERI, Taejon (Korea, Republic of)

    2001-10-01

    The non-destructive nuclear material detection technique is one of the novel methods under somewhat dangerous environments, for example, high level radiation or landmine areas. Specially, the detection of a landmine is a hot issue on the peaceful use of nuclear technology for human welfare. Generally, the explosives contain specific elements such as {sup 14}N or {sup 35}Cl. The photo-nuclear resonance gamma-rays are produced by nuclear reaction {sup 13}C(p , {gamma}){sup 14}N or {sup 34}S(p, {gamma}){sup 35}Cl in which target is bombarded by about 2MeV proton beam extracted from the proton accelerator. To avoid other neighboring resonant gamma-rays, we selected a higher resonant energy above 5MeV. The resonance gamma rays produced are absorbed or scattered when they react with {sup 14}N or {sup 35}Cl included in the mines and explosive. We can determine existence and position of mines or explosives by detecting the absorption and scattering gamma-ray signals.

  2. Nuclear viscosity and heavy-ion fusion-fission reactions

    International Nuclear Information System (INIS)

    Recently measured properties of the pre-scission particle emission from heavy-ion fusion-fission reactions of systems with A ∼ 200 were analysed using the latest version of the statistical model code JOANNE. Simultaneous fits to the multiplicities of pre-scission neutrons, protons and alpha-particles and their mean kinetic energies can be obtained when the deformation dependence of both the particle transmission coefficients and particle binding energies are taken into account. The emission of protons and alpha-particles is found to be suppressed relative to the neutron emission with increasing nuclear deformation. If the Fermi-gas level density parameter α is assumed to be independent of deformation then the experimental pre-scission particle data are consistent with α = A/(8.8± 0.5) MeV-1, a total fission dynamical time scale of 18 ± 5X10-21 s with a pre-saddle time of 5 ± 2x10-21 s and a saddle-to-scission transition time of 13 ±4x10-21 s. These time scales, along with the widths of isoscalar giant quadrupole and octupole resonances and the kinetic energy of fission fragments from systems with A ∼ 200, are consistent with the surface-plus-window dissipation model with the full one-body wall formula scaling factor ks ∼ 0.3 for compact configurations and ks ∼ 0.6 for highly deformed nuclear shapes. 25 refs., 1 tab., 10 figs

  3. Nuclear reactions with radioactive and stable beams (Part II)

    International Nuclear Information System (INIS)

    At the present time there is a great interest at world level in experiments, with accelerated nuclei of short half life. The dispersion, fusion, transfer and break processes in the interaction of weakly light projectiles bounded with targets of Z great its have been object of intense recent investigation, at world level. Our group, in collaboration with the University of Notre Dame, it has measured and analyzed these processes for weakly bound systems as: 6He + 209Bi, 8Li + 208Pb, 10Be + 208Pb. On the other hand a research line that has wakened up great interest, it is that of studies of resonant reactions using the Inverse Kinematics technique with thick targets. The use of this technique allows to measure an entire excitation function with a single bombardment. Our group has carried out, in the ININ, preliminary bombardments for the system 12C + 4He. This allowed to establish the feasibility of implementing this technique in our Laboratory. The application of this and other techniques to different systems like 18O + 4He, 12C + 12C, 12C + 16O, 16O + 16O, it opens the possibility to measure the fusion of these systems at very low energy and to deepen in the knowledge of the nuclear structure and the nuclear astrophysics. In this technical report, the activities carried out by our group during the second stage of this project, considered for 2005 are described. Also in that year, our group carries out a research stay in the University of Notre Dame, during this stay, the angular distribution of the projectiles of 8B dispersed in an enriched target of 58Ni was measured. The same as in the previous experiments, in this occasion it was also possible to measure those angular distributions of the projectiles of 7Be and 6Li dispersed in this same target. In this same one our stay group participates in other three experiments proposed by collaborators of other institutions (University of Notre Dame, University of Sao Paulo), where the products of the reactions 6Li, 7Be and

  4. Reaction dynamics and nuclear structure of moderately neutron-rich Ne isotopes by heavy ion reactions

    Directory of Open Access Journals (Sweden)

    Bottoni S.

    2014-03-01

    Full Text Available The heavy ion reaction 22Ne+208Pb at 128 MeV of bombarding energy has been studied using the PRISMA-CLARA experimental setup at Legnaro National Laboratories. Elastic, inelastic and one nucleon transfer cross sections have been measured. The experimental results are presented in parallel with the analysis on existing data for the unstable 24Ne nucleus, from the reaction 24Ne+208Pb at 182 MeV (measured at SPIRAL with the VAMOS-EXOGAM setup. The β2C charge deformation parameter for both 22Ne and 24Ne has been determined by a DWBA analysis of the experimental angular dis- tributions, showing a strong reduction for 24Ne.

  5. Exclusive measurements of nuclear breakup reactions of 17Ne

    Directory of Open Access Journals (Sweden)

    Wamers F.

    2014-03-01

    Full Text Available We have studied one-proton-removal reactions of about 500MeV/u 17Ne beams on a carbon target at the R3B/LAND setup at GSI by detecting beam-like 15O-p and determining their relative-energy distribution. We exclusively selected the removal of a 17Ne halo proton, and the Glauber-model analysis of the 16F momentum distribution resulted in an s2 contribution in the 17Ne ground state of about 40%.

  6. Towards an unified microscopic approach of the description of the nuclear structure and reaction

    International Nuclear Information System (INIS)

    This thesis contains 3 main parts. The first one: nuclear matter. The motivation of the study is to establish a link between the bare nucleon-nucleon interaction and nuclear matter properties. The properties of nuclear matter are examined using finite range effective interactions either derived from the Brueckner theory or determined in a purely phenomenological way. Skyrme-type interactions are also used for comparison. We have focused our discussion on several main aspects: the pressure ins symmetric nuclear matter and in neutron matter, the density dependence of the symmetric energy S and the nuclear matter incompressibility. The second part: the structure of finite nuclei and of the inner crust of neutrons stars. We present the non-relativistic HF and HF-BCS approaches in coordinate representation using finite-range density-dependent interactions in both the mean field and pairing channels. An iterative scheme is used for solving the integral-differential HF equations. We have studied the doubly magic nuclei, the Sn isotopes and the possible occurrence of bubble structures in the nuclei O22, Si34, Ar46 and Ar68. We have also examined the different zones of the inner crust of neutron stars. The third part: nuclear reactions. Using the same effective interactions derived from the Brueckner theory we have performed a coupled channel analysis of (p,n) charge exchange reactions at 35 and 45 MeV incident energies on Ca48, Zr90, Sn120 and Pb208 targets leading to isobaric analog states. (A.C.)

  7. RIPL - Reference Input Parameter Library for Calculation of Nuclear Reactions and Nuclear Data Evaluations

    Science.gov (United States)

    Capote, R.; Herman, M.; Obložinský, P.; Young, P. G.; Goriely, S.; Belgya, T.; Ignatyuk, A. V.; Koning, A. J.; Hilaire, S.; Plujko, V. A.; Avrigeanu, M.; Bersillon, O.; Chadwick, M. B.; Fukahori, T.; Ge, Zhigang; Han, Yinlu; Kailas, S.; Kopecky, J.; Maslov, V. M.; Reffo, G.; Sin, M.; Soukhovitskii, E. Sh.; Talou, P.

    2009-12-01

    We describe the physics and data included in the Reference Input Parameter Library, which is devoted to input parameters needed in calculations of nuclear reactions and nuclear data evaluations. Advanced modelling codes require substantial numerical input, therefore the International Atomic Energy Agency (IAEA) has worked extensively since 1993 on a library of validated nuclear-model input parameters, referred to as the Reference Input Parameter Library (RIPL). A final RIPL coordinated research project (RIPL-3) was brought to a successful conclusion in December 2008, after 15 years of challenging work carried out through three consecutive IAEA projects. The RIPL-3 library was released in January 2009, and is available on the Web through http://www-nds.iaea.org/RIPL-3/. This work and the resulting database are extremely important to theoreticians involved in the development and use of nuclear reaction modelling (ALICE, EMPIRE, GNASH, UNF, TALYS) both for theoretical research and nuclear data evaluations. The numerical data and computer codes included in RIPL-3 are arranged in seven segments: MASSES contains ground-state properties of nuclei for about 9000 nuclei, including three theoretical predictions of masses and the evaluated experimental masses of Audi et al. (2003). DISCRETE LEVELS contains 117 datasets (one for each element) with all known level schemes, electromagnetic and γ-ray decay probabilities available from ENSDF in October 2007. NEUTRON RESONANCES contains average resonance parameters prepared on the basis of the evaluations performed by Ignatyuk and Mughabghab. OPTICAL MODEL contains 495 sets of phenomenological optical model parameters defined in a wide energy range. When there are insufficient experimental data, the evaluator has to resort to either global parameterizations or microscopic approaches. Radial density distributions to be used as input for microscopic calculations are stored in the MASSES segment. LEVEL DENSITIES contains

  8. Tables of nuclear cross sections and reaction rates: An addendum to the paper 'Astrophysical reaction rates from satistical model calculations'

    International Nuclear Information System (INIS)

    In a previous publication (ATOMIC DATA AND NUCLEAR DATA TABLES75, 1 (2000)), we gave seven-parameter analytical fits to theoretical reaction rates derived from nuclear cross sections calculated in the statistical model (Hauser-Feshbach formalism) for targets with 10≤Z≤83 (Ne to Bi) and for a mass range reaching the neutron and proton driplines. Reactions considered were (n,γ), (n,p), (n,α), (p,γ), (p,α), (α,γ), and their inverse reactions. Here, we present the theoretical nuclear cross sections and astrophysical reaction rates from which those rate fits were derived, and we provide these data as on-line electronic files. Corresponding to the fitted rates, two complete data sets are provided, one of which includes a phenomenological treatment of shell quenching for neutron-rich nuclei

  9. A taxonomy of integral reaction path analysis

    Energy Technology Data Exchange (ETDEWEB)

    Grcar, Joseph F.; Day, Marcus S.; Bell, John B.

    2004-12-23

    W. C. Gardiner observed that achieving understanding through combustion modeling is limited by the ability to recognize the implications of what has been computed and to draw conclusions about the elementary steps underlying the reaction mechanism. This difficulty can be overcome in part by making better use of reaction path analysis in the context of multidimensional flame simulations. Following a survey of current practice, an integral reaction flux is formulated in terms of conserved scalars that can be calculated in a fully automated way. Conditional analyses are then introduced, and a taxonomy for bidirectional path analysis is explored. Many examples illustrate the resulting path analysis and uncover some new results about nonpremixed methane-air laminar jets.

  10. Search for K(bar) nuclear clusters in proton induced reactions with FOPI at GSI

    International Nuclear Information System (INIS)

    Full text: Recently the existence of exotic nuclear states involving K(bar) was predicted. It was argued that the attractive I = 0 K(bar) N force acts as a mediator, which allows the formation of deeply bound kaonic states which are commonly referred to as kaonic nuclear clusters. The lightest of these systems, K-pp was predicted to exist with a mass of 2.32 GeV/c2, a width of 61 MeV and with an average density of 3 times the normal nuclear density. Independent calculations confirmed the possible existence of these states, however with varying properties. Different techniques to produce and measure kaonic nuclear clusters have been proposed and a few attempts have been made to experimentally prove their existence. However, the results so far are not conclusive. In 2005 we started a program at GSI with the goal to produce K-pp in p+d/C reactions and to verify its creation with the FOPI detector by means of an invariant mass and missing mass analysis. A first test experiment was carried out in Fall 2005. Based on this experience a new proposal was worked out to investigate the reaction p + p → K-pp + K+, which was approved by the Program Advisory Committee of GSI. In this talk we will report on the results from the test experiment and line out the concepts of the newly proposed experiment.With the limited statistics obtained during the test experiment it was not possible to verify or rule out the existence of kaonic nuclear clusters. However, the data was used to test data analysis concepts and allowed to identify possibilities for improvement of the experimental setup for the follow-up experiment. (author)

  11. Introduction to the cluster formation theory. Application to the nuclear fragmentation reactions

    International Nuclear Information System (INIS)

    This course reviews the theory of geometrical models of cluster formation in nuclear reactions. After an elementary introduction to the theory of critical phenomena, illustrated by percolation models, we discuss kinetic theories of aggregation and fragmentation. The realization of these ideas in the context of nuclear fragmentation reactions and the search of signals of phase transitions is also reviewed

  12. Nuclear Reactions: Studying Peaceful Applications in the Middle and Secondary School.

    Science.gov (United States)

    Szymanski Sunal, Cynthia; Sunal, Dennis W.

    1999-01-01

    Asserts that students must learn about nuclear fission and fusion in the social studies curriculum to help them develop a foundation for considering the social issues associated with the everyday use of nuclear reactions. Gives background on the two types of reactions and provides three lessons for middle and secondary classrooms. (CMK)

  13. The analysis of Al-based alloys by calorimetry: quantitative analysis of reactions and reaction kinetics

    OpenAIRE

    Starink, M.J.

    2004-01-01

    Differential scanning calorimetry (DSC) and isothermal calorimetry have been applied extensively to the analysis of light metals, especially Al based alloys. Isothermal calorimetry and differential scanning calorimetry are used for analysis of solid state reactions, such as precipitation, homogenisation, devitrivication and recrystallisation; and solid–liquid reactions, such as incipient melting and solidification, are studied by differential scanning calorimetry. In producing repeatable calo...

  14. Nuclear Proliferation Technology Trends Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zentner, Michael D.; Coles, Garill A.; Talbert, Robert J.

    2005-10-04

    A process is underway to develop mature, integrated methodologies to address nonproliferation issues. A variety of methodologies (both qualitative and quantitative) are being considered. All have one thing in common, a need for a consistent set of proliferation related data that can be used as a basis for application. One approach to providing a basis for predicting and evaluating future proliferation events is to understand past proliferation events, that is, the different paths that have actually been taken to acquire or attempt to acquire special nuclear material. In order to provide this information, this report describing previous material acquisition activities (obtained from open source material) has been prepared. This report describes how, based on an evaluation of historical trends in nuclear technology development, conclusions can be reached concerning: (1) The length of time it takes to acquire a technology; (2) The length of time it takes for production of special nuclear material to begin; and (3) The type of approaches taken for acquiring the technology. In addition to examining time constants, the report is intended to provide information that could be used to support the use of the different non-proliferation analysis methodologies. Accordingly, each section includes: (1) Technology description; (2) Technology origin; (3) Basic theory; (4) Important components/materials; (5) Technology development; (6) Technological difficulties involved in use; (7) Changes/improvements in technology; (8) Countries that have used/attempted to use the technology; (9) Technology Information; (10) Acquisition approaches; (11) Time constants for technology development; and (12) Required Concurrent Technologies.

  15. Power Installations based on Activated Nuclear Reactions of Fission and Synthesis

    CERN Document Server

    Grigoriev, Yuriy

    2016-01-01

    The general scheme of power installations based on nuclear reactions of fission and synthesis activated by external sources is analyzed. The external activation makes possible to support nuclear reactions at temperatures and pressures lower than needed for chain reactions, so simplifies considerably practical realization of power installations. The possibility of operation on subcritical masses allows making installations compact and safe at emergency situations. Installations are suitable for transmutation of radioactive nuclides, what solves the problem of utilization of nuclear waste products. It is proposed and considered schemes of power installations based on nuclear reactions of fission and fusion, activated by external sources, different from ADS systems. Variants of activation of nuclear reactions of fission (U-235, 238, Pu-239) and fusion (Li-6,7, B-10,11) are considered.

  16. Uncovering Special Nuclear Materials by Low-energy Nuclear Reaction Imaging

    Science.gov (United States)

    Rose, P. B.; Erickson, A. S.; Mayer, M.; Nattress, J.; Jovanovic, I.

    2016-01-01

    Weapons-grade uranium and plutonium could be used as nuclear explosives with extreme destructive potential. The problem of their detection, especially in standard cargo containers during transit, has been described as “searching for a needle in a haystack” because of the inherently low rate of spontaneous emission of characteristic penetrating radiation and the ease of its shielding. Currently, the only practical approach for uncovering well-shielded special nuclear materials is by use of active interrogation using an external radiation source. However, the similarity of these materials to shielding and the required radiation doses that may exceed regulatory limits prevent this method from being widely used in practice. We introduce a low-dose active detection technique, referred to as low-energy nuclear reaction imaging, which exploits the physics of interactions of multi-MeV monoenergetic photons and neutrons to simultaneously measure the material’s areal density and effective atomic number, while confirming the presence of fissionable materials by observing the beta-delayed neutron emission. For the first time, we demonstrate identification and imaging of uranium with this novel technique using a simple yet robust source, setting the stage for its wide adoption in security applications. PMID:27087555

  17. Uncovering Special Nuclear Materials by Low-energy Nuclear Reaction Imaging

    Science.gov (United States)

    Rose, P. B.; Erickson, A. S.; Mayer, M.; Nattress, J.; Jovanovic, I.

    2016-04-01

    Weapons-grade uranium and plutonium could be used as nuclear explosives with extreme destructive potential. The problem of their detection, especially in standard cargo containers during transit, has been described as “searching for a needle in a haystack” because of the inherently low rate of spontaneous emission of characteristic penetrating radiation and the ease of its shielding. Currently, the only practical approach for uncovering well-shielded special nuclear materials is by use of active interrogation using an external radiation source. However, the similarity of these materials to shielding and the required radiation doses that may exceed regulatory limits prevent this method from being widely used in practice. We introduce a low-dose active detection technique, referred to as low-energy nuclear reaction imaging, which exploits the physics of interactions of multi-MeV monoenergetic photons and neutrons to simultaneously measure the material’s areal density and effective atomic number, while confirming the presence of fissionable materials by observing the beta-delayed neutron emission. For the first time, we demonstrate identification and imaging of uranium with this novel technique using a simple yet robust source, setting the stage for its wide adoption in security applications.

  18. Uncovering Special Nuclear Materials by Low-energy Nuclear Reaction Imaging.

    Science.gov (United States)

    Rose, P B; Erickson, A S; Mayer, M; Nattress, J; Jovanovic, I

    2016-04-18

    Weapons-grade uranium and plutonium could be used as nuclear explosives with extreme destructive potential. The problem of their detection, especially in standard cargo containers during transit, has been described as "searching for a needle in a haystack" because of the inherently low rate of spontaneous emission of characteristic penetrating radiation and the ease of its shielding. Currently, the only practical approach for uncovering well-shielded special nuclear materials is by use of active interrogation using an external radiation source. However, the similarity of these materials to shielding and the required radiation doses that may exceed regulatory limits prevent this method from being widely used in practice. We introduce a low-dose active detection technique, referred to as low-energy nuclear reaction imaging, which exploits the physics of interactions of multi-MeV monoenergetic photons and neutrons to simultaneously measure the material's areal density and effective atomic number, while confirming the presence of fissionable materials by observing the beta-delayed neutron emission. For the first time, we demonstrate identification and imaging of uranium with this novel technique using a simple yet robust source, setting the stage for its wide adoption in security applications.

  19. Uncovering Special Nuclear Materials by Low-energy Nuclear Reaction Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Rose Jr., P.B.; Erickson, A. S.; Mayer, Michael F.; Nattress, J.; Jovanovic , I

    2016-04-18

    Weapons-grade uranium and plutonium could be used as nuclear explosives with extreme destructive potential. The problem of their detection, especially in standard cargo containers during transit, has been described as “searching for a needle in a haystack” because of the inherently low rate of spontaneous emission of characteristic penetrating radiation and the ease of its shielding. Currently, the only practical approach for uncovering well-shielded special nuclear materials is by use of active interrogation using an external radiation source. However, the similarity of these materials to shielding and the required radiation doses that may exceed regulatory limits prevent this method from being widely used in practice. We introduce a low-dose active detection technique, referred to as low-energy nuclear reaction imaging, which exploits the physics of interactions of multi-MeV monoenergetic photons and neutrons to simultaneously measure the material’s areal density and effective atomic number, while confirming the presence of fissionable materials by observing the beta-delayed neutron emission. For the first time, we demonstrate identification and imaging of uranium with this novel technique using a simple yet robust source, setting the stage for its wide adoption in security applications.

  20. Analysis of transfer reactions: determination of spectroscopic factors

    Energy Technology Data Exchange (ETDEWEB)

    Keeley, N. [CEA Saclay, Dept. d' Astrophysique, de Physique des Particules de Physique Nucleaire et de l' Instrumentation Associee (DSM/DAPNIA/SPhN), 91- Gif sur Yvette (France); The Andrzej So an Institute for Nuclear Studies, Dept. of Nuclear Reactions, Warsaw (Poland)

    2007-07-01

    An overview of the most popular models used for the analysis of direct reaction data is given, concentrating on practical aspects. The 4 following models (in order of increasing sophistication): the distorted wave born approximation (DWBA), the adiabatic model, the coupled channels born approximation, and the coupled reaction channels are briefly described. As a concrete example, the C{sup 12}(d,p)C{sup 13} reaction at an incident deuteron energy of 30 MeV is analysed with progressively more physically sophisticated models. The effect of the choice of the reaction model on the spectroscopic information extracted from the data is investigated and other sources of uncertainty in the derived spectroscopic factors are discussed. We have showed that the choice of the reaction model can significantly influence the nuclear structure information, particularly the spectroscopic factors or amplitudes but occasionally also the spin-parity, that we wish to extract from direct reaction data. We have also demonstrated that the DWBA can fail to give a satisfactory description of transfer data but when the tenets of the theory are fulfilled DWBA can work very well and will yield the same results as most sophisticated models. The use of global rather than fitted optical potentials can also lead to important differences in the extracted spectroscopic factors.

  1. Investigations of nuclear structure and nuclear reactions induced by complex projectiles. Technical progress report, November 1, 1978-October 31, 1979. [Summaries of research activities at Washington Univ

    Energy Technology Data Exchange (ETDEWEB)

    Sarantites, D.G.

    1979-01-01

    Experimental research on nuclear structure and reactions both published and in progress is summarized. Included are fusion reactions, strongly damped heavy ion collisions, and nuclear structure at high angular momentum. A list of publications is included. (JFP)

  2. MFE damage analysis program nuclear data needs

    International Nuclear Information System (INIS)

    Nuclear data needs for the ERDA-DMFE Damage Analysis and Fundamental Studies program fall into three categories: reaction cross sections for dosimetry, cross sections for transmutation reactions, especially those producing helium and hydrogen, and differential scattering cross sections and emitted particle angular and energy distributions for calculating primary recoil spectra. The ENDF/B Dosimetry File must be expanded and extended to 30 to 40 MeV (specific reactions are given); integral testing of cross sections in high energy fields is especially needed. Gas production files must also be extended to 30 to 40 MeV although high accuracy is not generally needed. Direct measurements of accumulated helium can be made. Cross sections must be adequate in the 15 to 40 MeV range to estimate solid transmutant concentrations as well. Sensitivity studies are desirable to assess needed accuracies of cross sections and emission spectra for damage calculations. For this application, it may be that theoretical calculations, supplemented by a limited experimental program, will suffice

  3. Modeled Neutron Induced Nuclear Reaction Cross Sections for Radiochemistry in the region of Iriduim and Gold

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, R D; Dietrich, F S; Kelley, K; Escher, J; Bauer, R; Mustafa, M

    2008-02-26

    We have developed a set of modeled nuclear reaction cross sections for use in radiochemical diagnostics. Systematics for the input parameters required by the Hauser-Feshbach statistical model were developed and used to calculate neutron induced nuclear reaction cross sections for targets ranging from osmium (Z = 76) to gold (Z = 79). Of particular interest are the cross sections on Ir and Au including reactions on isomeric targets.

  4. Investigations of nuclear projectile break-up reactions

    International Nuclear Information System (INIS)

    The cross sections for radiative capture of α-particles, deuterons and protons by light nuclei at very low relative energies are of particular importance for the understanding of the nucleosynthesis of chemical elements and for determining the relative elemental abundances in stellar burning processes at various astrophysical sites. As example we quote the reactions α+d → 6Li+γ, α+3He → 7Be+γ, or α+12C → 16O+γ. As an alternative to the direct experimental study of these processes we consider the inverse process, the photodisintegration, by means of the virtual photons provided by a nuclear Coulomb field: Z+a → Z+b+c. The radiative capture process b+c → a+γ is related to the inverse process, the photodisintegration γ+a → b+c by the detailed balance theorem. Except for the extreme case very close to the threshold the phase space favours the photodisintegration cross section as compared to the radiative capture. The Coulomb dissociation cross section proves to be enhanced due to the large virtual photon number, seen by the passing projectile, and the kinematics of the process leads to particular advantages for studies of the interaction of the two break-up fragments at small relative energies Ebc. The conditions of dedicated experimental investigations are discussed and demonstrated by recent experimental and theoretical studies of the break-up of 156 MeV 6Li projectiles. In addition, a brief review about general features of break-up processes of light ions in the field of atomic nuclei is given. (orig.)

  5. The effect of nuclear structure in the emission of reaction products in heavy-ion reactions

    Indian Academy of Sciences (India)

    Samir Kundu

    2014-04-01

    Study of intermediate mass fragments (IMFs) and light charged particles (LCPs) emission has been carried out for a few reactions involving -cluster and non--cluster systems to see how the emission processes are affected by nuclear clustering. Li, Be, B and -particles have been studied from α-clustered system 16O + 12C for 117, 125, 145 and 160 MeV bombarding energies respectively. The enhanced yields of near-entrance channel fragment B and large quadrupole deformation of the produced composite 28Si* extracted from LCP spectra indicate the survival of orbiting-like process in 16O + 12C system at these energies. The same IMFs emitted from the -cluster system 12C (77 MeV) + 28Si and nearby non- cluster 11B (64 MeV) + 28Si and 12C (73 MeV) + 27Al (all having the same excitation energy of ∼67 MeV) have also been studied. The fully energy damped (fusion–fission) and the partially energy damped (deep inelastic) components of the fragment energy spectra have been extracted. It has been found that the yields of the fully energy damped fragments for all the above reactions are in conformity with the respective statistical model predictions. The time-scales of various deep inelastic fragment emissions have been extracted from the angular distribution data. The angular momentum dissipation in deep inelastic collisions has been estimated from the data and it has been found to be close to the corresponding sticking limit value.

  6. Nuclear-Pumped Lasers. [efficient conversion of energy liberated in nuclear reactions to coherent radiation

    Science.gov (United States)

    1979-01-01

    The state of the art in nuclear pumped lasers is reviewed. Nuclear pumped laser modeling, nuclear volume and foil excitation of laser plasmas, proton beam simulations, nuclear flashlamp excitation, and reactor laser systems studies are covered.

  7. Stimulated Emission of Radiation in a Nuclear Fusion Reaction

    OpenAIRE

    Duren, Michael

    1999-01-01

    This letter claims that process of stimulated emission of radiation can be used to induce a fusion reaction in a HD molecule to produce Helium-3. An experimental set-up for this reaction is presented. It is proposed to study the technical potential of this reaction as an energy amplifier.

  8. Effective interaction: From nuclear reactions to neutron stars

    Indian Academy of Sciences (India)

    D N Basu

    2014-05-01

    An equation of state (EoS) for symmetric nuclear matter is constructed using the density-dependent M3Y effective interaction and extended for isospin asymmetric nuclear matter. Theoretically obtained values of symmetric nuclear matter incompressibility, isobaric incompressibility, symmetry energy and its slope agree well with experimentally extracted values. Folded microscopic potentials using this effective interaction, whose density dependence is determined from nuclear matter calculations, provide excellent descriptions for proton, alpha and cluster radioactivities, elastic and inelastic scattering. The nuclear deformation parameters extracted from inelastic scattering of protons agree well with other available results. The high density behaviour of symmetric and asymmetric nuclear matter satisfies the constraints from the observed flow data of heavy-ion collisions. The neutron star properties studied using -equilibrated neutron star matter obtained from this effective interaction reconcile with the recent observations of the massive compact stars.

  9. TALYS-1.0, computes nuclear reactions cross-sections, yields and spectra via a comprehensive set of nuclear models

    International Nuclear Information System (INIS)

    1 - Description of program or function: TALYS is software for the simulation of nuclear reactions. Many state-of-the-art nuclear models are included to cover all main reaction mechanisms encountered in light particle-induced nuclear reactions. TALYS provides a complete Description of all reaction channels and observables. It is a versatile tool to analyse basic microscopic experiments and to generate nuclear data for applications. Specific features of the TALYS package : - an exact implementation of many of the latest nuclear models for direct, compound, pre-equilibrium and fission reactions. - a continuous, smooth Description of reaction mechanisms over a wide energy range (0.001- 200 MeV) and mass number range (12 < A < 339). - completely integrated optical model and coupled-channels calculations by the ECIS-06 code - incorporation of recent optical model parameterizations for many nuclei, both phenomenological (optionally including dispersion relations) and microscopical. - total and partial cross sections, energy spectra, angular distributions, double-differential spectra and recoils. - discrete and continuum photon production cross sections. - excitation functions for residual nuclide production, including isomeric cross sections. - exact modeling of exclusive channel cross sections, e.g. (n; 2np), spectra, and recoils. - automatic reference to nuclear structure parameters as masses, discrete levels, resonances, level density parameters, deformation parameters, fission barrier and gamma-ray parameters, generally from the IAEA Reference Input Parameter Library - various width fluctuation models for binary compound reactions and, at higher energies, multiple Hauser-Feshbach emission until all reaction channels are closed. - various phenomenological and microscopic level density models. - various fission models to predict cross sections and fission fragment and product yields. - models for pre-equilibrium reactions, and multiple pre-equilibrium reactions up to

  10. 11. IAEA consultants' meeting of the nuclear reaction data centers. Obninsk, 7-11 October 1991

    International Nuclear Information System (INIS)

    This report summarizes the 1991 co-ordination meeting in Obninsk, Russia, of the national and regional nuclear reaction data centers, convened by the IAEA at regular intervals. The main topics are: the international exchange of nuclear reaction data by means of the ''EXFOR'' system, and the further development of this system; the ''CINDA'' system as an international index and bibliography to neutron reaction data; the sharing of the workload for speedy and reliable nuclear data compilation; the exchanged and documentation of evaluated data libraries in ENDF format, with the goal of rendering data center services to data users in IAEA Member States by means of computer retrievals, online services and printed materials

  11. Impact of Nuclear Reaction Uncertainties on AGB Nucleosynthesis Models

    CERN Document Server

    Bisterzo, S; Kaeppeler, F; Wiescher, M; Travaglio, C

    2012-01-01

    Asymptotic giant branch (AGB) stars with low initial mass (1 - 3 Msun) are responsible for the production of neutron-capture elements through the main s-process (main slow neutron capture process). The major neutron source is 13C(alpha, n)16O, which burns radiatively during the interpulse periods at about 8 keV and produces a rather low neutron density (10^7 n/cm^3). The second neutron source 22Ne(alpha, n)25Mg, partially activated during the convective thermal pulses when the energy reaches about 23 keV, gives rise to a small neutron exposure but a peaked neutron density (Nn(peak) > 10^11 n/cm^3). At metallicities close to solar, it does not substantially change the final s-process abundances, but mainly affects the isotopic ratios near s-path branchings sensitive to the neutron density. We examine the effect of the present uncertainties of the two neutron sources operating in AGB stars, as well as the competition with the 22Ne(alpha, gamma)26Mg reaction. The analysis is carried out on AGB the main-s process...

  12. Databases and tools for nuclear astrophysics applications BRUSsels Nuclear LIBrary (BRUSLIB), Nuclear Astrophysics Compilation of REactions II (NACRE II) and Nuclear NETwork GENerator (NETGEN)

    CERN Document Server

    Xu, Yi; Jorissen, Alain; Chen, Guangling; Arnould, Marcel; 10.1051/0004-6361/201220537

    2012-01-01

    An update of a previous description of the BRUSLIB+NACRE package of nuclear data for astrophysics and of the web-based nuclear network generator NETGEN is presented. The new version of BRUSLIB contains the latest predictions of a wide variety of nuclear data based on the most recent version of the Brussels-Montreal Skyrme-HFB model. The nuclear masses, radii, spin/parities, deformations, single-particle schemes, matter densities, nuclear level densities, E1 strength functions, fission properties, and partition functions are provided for all nuclei lying between the proton and neutron drip lines over the 8<=Z<=110 range, whose evaluation is based on a unique microscopic model that ensures a good compromise between accuracy, reliability, and feasibility. In addition, these various ingredients are used to calculate about 100000 Hauser-Feshbach n-, p-, a-, and gamma-induced reaction rates based on the reaction code TALYS. NACRE is superseded by the NACRE II compilation for 15 charged-particle transfer react...

  13. The CCONE Code System and its Application to Nuclear Data Evaluation for Fission and Other Reactions

    Science.gov (United States)

    Iwamoto, O.; Iwamoto, N.; Kunieda, S.; Minato, F.; Shibata, K.

    2016-01-01

    A computer code system, CCONE, was developed for nuclear data evaluation within the JENDL project. The CCONE code system integrates various nuclear reaction models needed to describe nucleon, light charged nuclei up to alpha-particle and photon induced reactions. The code is written in the C++ programming language using an object-oriented technology. At first, it was applied to neutron-induced reaction data on actinides, which were compiled into JENDL Actinide File 2008 and JENDL-4.0. It has been extensively used in various nuclear data evaluations for both actinide and non-actinide nuclei. The CCONE code has been upgraded to nuclear data evaluation at higher incident energies for neutron-, proton-, and photon-induced reactions. It was also used for estimating β-delayed neutron emission. This paper describes the CCONE code system indicating the concept and design of coding and inputs. Details of the formulation for modelings of the direct, pre-equilibrium and compound reactions are presented. Applications to the nuclear data evaluations such as neutron-induced reactions on actinides and medium-heavy nuclei, high-energy nucleon-induced reactions, photonuclear reaction and β-delayed neutron emission are mentioned.

  14. Co-ordination of the nuclear reaction data centers. Report on an IAEA advisory group meeting

    International Nuclear Information System (INIS)

    This report summarizes the 1996 co-ordination meeting in Brookhaven, U.S.A., of the national and regional nuclear reaction data center, convened by the IAEA at regular intervals. The main topics are: the international exchange of nuclear reaction data by means of the ''EXFOR'' system, and the further development of this system; the ''CINDA'' system as an international index and bibliography to neutron reaction data; the sharing of the workload for speedy and reliable nuclear data compilation and data center services; the exchange and documentation of evaluated data libraries in ''ENDF'' format; the rapid advances of online electronic information technologies, with the goal of rendering data center services to data users in IAEA Member States by means of computer retrievals, online services and printed materials. The scope of data covers microscopic cross-sections and related parameters of nuclear reactions induced by neutrons, charged-particles and photons. (author). Refs, figs, tabs

  15. Co-ordination of the nuclear reactions data centers. Report on an IAEA advisory group meeting

    International Nuclear Information System (INIS)

    This report summarizes the 1998 co-ordination meeting at the IAEA Headquarters in Vienna of the regional, national and specialized nuclear reaction data centers, concerned by the IAEA at two-year intervals. The main topics are: the international exchange of nuclear reaction data by means of the ''EXFOR'' system, and the further development of this system; the ''CINDA'' system as an international index and bibliography to neutron reaction data; the sharing of the workload for speedy and reliable nuclear data compilation and data center services; the exchange and documentation of evaluated data libraries in ''ENDF'' format; the rapid advances of online electronic information technologies, with goal of rendering data center services to data users in IAEA Member States by means of computer retrievals, online services and printed materials. The scope of data covers microscopic cross-sections and related parameters of nuclear reactions induced by neutrons, charged-particles and photons. (author)

  16. Nuclear excitations and reaction mechanisms: Progress report: [1 August 1986-31 July 1987

    International Nuclear Information System (INIS)

    Completed and ongoing research includes various theoretical and numerical studies of few-nucleon systems; nuclear reaction models; photon scattering from nuclei, including sum rules and current conservation; and properties of the pion

  17. Surveillance of nuclear instruments by noise analysis

    International Nuclear Information System (INIS)

    The neutron noise analysis allows the surveillance of nuclear instruments. The method consists in the calculation of an indicator of detector good operating by a signal analysis technique. A change of this indicator shows a degradation of the static and dynamic detector behaviour. Examples of applications in nuclear plants are given

  18. Summary Report of the Workshop on The Experimental Nuclear Reaction Data Database

    Energy Technology Data Exchange (ETDEWEB)

    Semkova, V. [IAEA Nuclear Data Section, Vienna (Austria); Pritychenko, B. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-10-10

    The Workshop on the Experimental Nuclear Reaction Data Database (EXFOR) was held at IAEA Headquarters in Vienna from 6 to 10 October 2014. The workshop was organized to discuss various aspects of the EXFOR compilation process including compilation rules, different techniques for nuclear reaction data measurements, software developments, etc. A summary of the presentations and discussions that took place during the workshop is reported here.

  19. Shell and explosive hydrogen burning. Nuclear reaction rates for hydrogen burning in RGB, AGB and Novae

    Energy Technology Data Exchange (ETDEWEB)

    Boeltzig, A. [Gran Sasso Science Institute, L' Aquila (Italy); Bruno, C.G.; Davinson, T. [University of Edinburgh, SUPA, School of Physics and Astronomy, Edinburgh (United Kingdom); Cavanna, F.; Ferraro, F. [Dipartimento di Fisica, Universita di Genova (Italy); INFN, Genova (Italy); Cristallo, S. [Osservatorio Astronomico di Collurania, INAF, Teramo (Italy); INFN, Napoli (Italy); Depalo, R. [Dipartimento di Fisica e Astronomia, Universita di Padova, Padova (Italy); INFN, Padova (Italy); DeBoer, R.J.; Wiescher, M. [University of Notre Dame, Institute for Structure and Nuclear Astrophysics, Joint Institute for Nuclear Astrophysics, Notre Dame, Indiana (United States); Di Leva, A.; Imbriani, G. [Dipartimento di Fisica, Universita di Napoli Federico II, Napoli (Italy); INFN, Napoli (Italy); Marigo, P. [Dipartimento di Fisica e Astronomia, Universita di Padova, Padova (Italy); Terrasi, F. [Dipartimento di Matematica e Fisica Seconda Universita di Napoli, Caserta (Italy); INFN, Napoli (Italy)

    2016-04-15

    The nucleosynthesis of light elements, from helium up to silicon, mainly occurs in Red Giant and Asymptotic Giant Branch stars and Novae. The relative abundances of the synthesized nuclides critically depend on the rates of the nuclear processes involved, often through non-trivial reaction chains, combined with complex mixing mechanisms. In this paper, we summarize the contributions made by LUNA experiments in furthering our understanding of nuclear reaction rates necessary for modeling nucleosynthesis in AGB stars and Novae explosions. (orig.)

  20. The reaction mechanism of the (3HE,T) reaction and applications to nuclear structure

    NARCIS (Netherlands)

    1986-01-01

    In this thesis we present a study on the reaction meachanism of the (3He,t) reaction at 70-80 MeV bombarding energy and on structures of the residual nuclei excited in this reaction: 24-Al, 26-Al, 28-P, 32-Cl, 40-Sc, 42-Sc and 58-Cu... Zie: Summary

  1. Total Nuclear Reaction Cross Section Induced by Halo Nuclei and Stable Nuclei

    Institute of Scientific and Technical Information of China (English)

    GUO Wen-Jun; JIANG Huan-Qing; LIU Jian-Ye; ZUO Wei; REN Zhong-Zhou; LEE Xi-Guo

    2003-01-01

    We develop a method for calculation of the total reaction cross sections induced by the halo nuclei and stable. nuclei. This approach is based on the Glauber theory, which is valid for nuclear reactions at high energies. It is extended for nuclear reactions at low energies and intermediate energies by including both the quantum correction and Coulomb correction under the assumption of the effective nuclear density distribution. The calculated results of the total reaction cross section induced by stable nuclei agree well with 30 experimental data within 10 percent accuracy. The comparison between the numerical results and 20 experimental data for the total nuclear reaction cross section induced by the neutron halo nuclei and the proton halo nuclei indicates a satisfactory agreement after considering the halo structure of these nuclei, which implies quite different mean fields for the nuclear reactions induced by halo nuclei and stable nuclei. The halo nucleon distributions and the root-mean-square radii of these nuclei can be extracted from the above comparison based on the improved Glauber model, which indicates clearly the halo structures of these nuclei. Especially,it is clear to see that the medium correction of the nucleon-nucleon collision has little effect on the total reaction cross sections induced by the halo nuclei due to the very weak binding and the very extended density distribution.

  2. Economic analysis of nuclear energy

    International Nuclear Information System (INIS)

    The objective of this study is to analyze how the economics of nuclear power generation are affected by the change in nuclear environmental factors and then, to suggest desirable policy directions to improve the efficiency of the use of nuclear energy resources in korea. This study focused to analyze the impact of the change in 3 major nuclear environmental factors in Korea on the economics of nuclear power generation. To do this, environmental external cost, nuclear R and fund, and carbon emission control according to UNFCCC were selected as the major factors. First of all, this study evaluated the impacts on the health and the environment of air pollutants emitted from coal power plant and nuclear power plant, two major electric power generating options in Korea. Then, the environmental external costs of those two options were estimated by transforming the health and environmental impact in to monetary values. To do this, AIRPACTS and 'Impacts of atmospheric release' model developed by IAEA were used. Secondly, the impact of nuclear R and D fund raised by the utility on the increment of nuclear power generating cost was evaluated. Then, the desirable size of the fund in Korea was suggested by taking into consideration the case of Japan. This study also analyzed the influences of the fund on the economics of nuclear power generation. Finally, the role of nuclear power under the carbon emission regulation was analyzed. To do this, the econometric model was developed and the impact of the regulation on the national economy was estimated. Further efforts were made to estimate the role by developing CGE model in order to improve the reliability of the results from the econometric model

  3. Study of components and statistical reaction mechanism in simulation of nuclear process for optimized production of 64Cu and 67Ga medical radioisotopes using TALYS, EMPIRE and LISE++ nuclear reaction and evaporation codes

    International Nuclear Information System (INIS)

    Production of medical radioisotopes is one of the most important tasks in the field of nuclear technology. These radioactive isotopes are mainly produced through variety nuclear process. In this research, excitation functions and nuclear reaction mechanisms are studied for simulation of production of these radioisotopes in the TALYS, EMPIRE and LISE++ reaction codes, then parameters and different models of nuclear level density as one of the most important components in statistical reaction models are adjusted for optimum production of desired radioactive yields

  4. EXFOR basics. A short guide to the nuclear reaction data exchange format

    International Nuclear Information System (INIS)

    EXFOR is the agreed exchange format for the transmission of experimental nuclear reaction data between national and international nuclear data centers for the benefit of nuclear data users in all countries. This report is intended as a guide to data users. For a complete guide to the EXFOR system see: EXFOR Systems Manual, IAEA-NDS-207 (BNL-NCS-63330-00/04-Rev.) (author)

  5. Nuclear parton distribution functions and energy loss effect in the Drell-Yan reaction off nuclei

    OpenAIRE

    Duan, ChunGui; Song, Lihua; Wang, ShuoHe; Li, Guanglie

    2006-01-01

    The energy loss effect in nuclear matter is another nuclear effect apart from the nuclear effects on the parton distribution as in deep inelastic scattering process. The quark energy loss can be measured best by the nuclear dependence of the high energy nuclear Drell-Yan process. By means of two typical kinds of quark energy loss parametrization and the different sets of nuclear parton distribution functions, we present a analysis of the E866 experiments on the nuclear dependence of Drell-Yan...

  6. Databases and tools for nuclear astrophysics applications. BRUSsels Nuclear LIBrary (BRUSLIB), Nuclear Astrophysics Compilation of REactions II (NACRE II) and Nuclear NETwork GENerator (NETGEN)

    Science.gov (United States)

    Xu, Y.; Goriely, S.; Jorissen, A.; Chen, G. L.; Arnould, M.

    2013-01-01

    An update of a previous description of the BRUSLIB + NACRE package of nuclear data for astrophysics and of the web-based nuclear network generator NETGEN is presented. The new version of BRUSLIB contains the latest predictions of a wide variety of nuclear data based on the most recent version of the Brussels-Montreal Skyrme-Hartree-Fock-Bogoliubov model. The nuclear masses, radii, spin/parities, deformations, single-particle schemes, matter densities, nuclear level densities, E1 strength functions, fission properties, and partition functions are provided for all nuclei lying between the proton and neutron drip lines over the 8 ≤ Z ≤ 110 range, whose evaluation is based on a unique microscopic model that ensures a good compromise between accuracy, reliability, and feasibility. In addition, these various ingredients are used to calculate about 100 000 Hauser-Feshbach neutron-, proton-, α-, and γ-induced reaction rates based on the reaction code TALYS. NACRE is superseded by the NACRE II compilation for 15 charged-particle transfer reactions and 19 charged-particle radiative captures on stable targets with mass numbers A < 16. NACRE II features the inclusion of experimental data made available after the publication of NACRE in 1999 and up to 2011. In addition, the extrapolation of the available data to the very low energies of astrophysical relevance is improved through the systematic use of phenomenological potential models. Uncertainties in the rates are also evaluated on this basis. Finally, the latest release v10.0 of the web-based tool NETGEN is presented. In addition to the data already used in the previous NETGEN package, it contains in a fully documented form the new BRUSLIB and NACRE II data, as well as new experiment-based radiative neutron capture cross sections. The full new versions of BRUSLIB, NACRE II, and NETGEN are available electronically from the nuclear database at http://www.astro.ulb.ac.be/NuclearData. The nuclear material is presented in

  7. Cutaneous reactions in nuclear, biological and chemical warfare

    Directory of Open Access Journals (Sweden)

    Arora Sandeep

    2005-03-01

    Full Text Available Nuclear, biological and chemical warfare have in recent times been responsible for an increasing number of otherwise rare dermatoses. Many nations are now maintaining overt and clandestine stockpiles of such arsenal. With increasing terrorist threats, these agents of mass destruction pose a risk to the civilian population. Nuclear and chemical attacks manifest immediately while biological attacks manifest later. Chemical and biological attacks pose a significant risk to the attending medical personnel. The large scale of anticipated casualties in the event of such an occurrence would need the expertise of all physicians, including dermatologists, both military and civilian. Dermatologists are uniquely qualified in this respect. This article aims at presenting a review of the cutaneous manifestations in nuclear, chemical and biological warfare and their management.

  8. Reactions of charged and neutral recoil particles following nuclear transformations. Progress report No. 10

    International Nuclear Information System (INIS)

    The status of the following programs is reported: study of the stereochemistry of halogen atom reactions produced via (n,γ) nuclear reactions with diastereomeric molecules in the condensed phase; decay-induced labelling of compounds of biochemical interest; and chemistry of positronium

  9. Multi-detector setup for nuclear astrophysical reaction studies on the low energy ion beam

    International Nuclear Information System (INIS)

    The multi-detector setup assembled on the basis of the ion beam from 'SOKOL' electrostatic accelerator is described. The setup allows one to measure three various spectra in a single experiment: prompt gamma-quanta from nuclear reactions, positrons from the decays of radioactive nuclei formed in the reactions and coincidence spectrum of annihilation gamma-quanta. (authors)

  10. Direct Reactions with Exotic Nuclei, Nuclear Structure and Astrophysics

    CERN Document Server

    Baur, G

    2006-01-01

    Intermediate energy Coulomb excitation and dissociation is a useful tool for nuclear structure and astrophysics studies. Low-lying strength in nuclei far from stability was discovered by this method. The effective range theory for low-lying strength in one-neutron halo nuclei is summarized and extended to two-neutron halo nuclei. This is of special interest in view of recent rather accurate experimental results on the low-lying electric dipole strength in $^{11}$Li. Another indirect approach to nuclear astrophysics is the Trojan horse method. It is pointed out that it is a suitable tool to investigate subthreshold resonances.

  11. Prospective analysis. Nuclear deterrence in 2030

    International Nuclear Information System (INIS)

    This study is a prospective analysis of the long-term future of nuclear weapons, and particularly the future of French nuclear deterrence after 2015. The selected time period is 2025-2030. The principal objective is to reflect on what the nuclear world might look like during the first part of the 21 st century, beyond the modernization decisions already planned or envisaged, and to draw conclusions for the future of the French deterrent. (author)

  12. Neutron Transfer Reactions: Surrogates for Neutron Capture for Basic and Applied Nuclear Science

    Science.gov (United States)

    Cizewski, J. A.; Jones, K. L.; Kozub, R. L.; Pain, S. D.; Peters, W. A.; Adekola, A.; Allen, J.; Bardayan, D. W.; Becker, J. A.; Blackmon, J. C.; Chae, K. Y.; Chipps, K. A.; Erikson, L.; Gaddis, A.; Harlin, C.; Hatarik, R.; Howard, J.; Jandel, M.; Johnson, M. S.; Kapler, R.; Krolas, W.; Liang, F.; Livesay, R. J.; Ma, Z.; Matei, C.; Matthews, C.; Moazen, B.; Nesaraja, C. D.; O'Malley, P.; Patterson, N.; Paulauskas, S. V.; Pelham, T.; Pittman, S. T.; Radford, D.; Rogers, J.; Schmitt, K.; Shapira, D.; Shriner, J. F.; Sissom, D. J.; Smith, M. S.; Swan, T.; Thomas, J. S.; Vieira, D. J.; Wilhelmy, J. B.; Wilson, G. L.

    2009-03-01

    Neutron capture reactions on unstable nuclei are important for both basic and applied nuclear science. A program has been developed at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory to study single-neutron transfer (d,p) reactions with rare isotope beams to provide information on neutron-induced reactions on unstable nuclei. Results from (d,p) studies on 130,132Sn, 134Te and 75As are discussed.

  13. Neutron transfer reactions: Surrogates for neutron capture for basic and applied nuclear science

    Energy Technology Data Exchange (ETDEWEB)

    Cizewski, J. A. [Rutgers University; Jones, K. L. [University of Tennessee; Kozub, R. L. [Tennessee Technological University; Pain, Steven D [ORNL; Peters, W. A. [Rutgers University; Adekola, Aderemi S [ORNL; Allen, J. [Rutgers University; Bardayan, Daniel W [ORNL; Becker, J. [Lawrence Livermore National Laboratory (LLNL); Blackmon, Jeff C [ORNL; Chae, K. Y. [University of Tennessee; Chipps, K. [Colorado School of Mines, Golden; Erikson, Luke [Colorado School of Mines, Golden; Gaddis, A. L. [Furman University; Harlin, Christopher W [ORNL; Hatarik, Robert [Rutgers University; Howard, Joshua A [ORNL; Jandel, M. [Los Alamos National Laboratory (LANL); Johnson, Micah [ORNL; Kapler, R. [University of Tennessee; Krolas, W. [University of Warsaw; Liang, J Felix [ORNL; Livesay, Jake [ORNL; Ma, Zhanwen [ORNL; Matei, Catalin [Oak Ridge Associated Universities (ORAU); Matthews, C. [Rutgers University; Moazen, Brian [University of Tennessee; Nesaraja, Caroline D [ORNL; O' Malley, Patrick [Rutgers University; Patterson, N. P. [University of Surrey, UK; Paulauskas, Stanley [University of Tennessee; Pelham, T. [University of Surrey, UK; Pittman, S. T. [University of Tennessee, Knoxville (UTK); Radford, David C [ORNL; Rogers, J. [Tennessee Technological University; Schmitt, Kyle [University of Tennessee; Shapira, Dan [ORNL; ShrinerJr., J. F. [Tennessee Technological University; Sissom, D. J. [Tennessee Technological University; Smith, Michael Scott [ORNL; Swan, T. P. [University of Surrey, UK; Thomas, J. S. [Rutgers University; Vieira, D. J. [Los Alamos National Laboratory (LANL); Wilhelmy, J. B. [Los Alamos National Laboratory (LANL); Wilson, Gemma L [ORNL

    2009-04-01

    Neutron capture reactions on unstable nuclei are important for both basic and applied nuclear science. A program has been developed at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory to study single-neutron transfer (d,p) reactions with rare isotope beams to provide information on neutron-induced reactions on unstable nuclei. Results from (d,p) studies on {sup 130,132}Sn, {sup 134}Te and {sup 75}As are discussed.

  14. The methods of multiparameter correlation measurements for the study of nuclear reactions

    International Nuclear Information System (INIS)

    The methods and procedures of multi-parameter correlation experiments for the study of nuclear reactions are developed. Computerized measurement system allows to determine the energy of reaction products, their charge and mass, to register and analyze the time and energy correlations of two- or three-particle coincident events. Developed system was tested and used in the experiments for the study of binary and three particle reactions d + 6Li and α + 7Li

  15. Oxygen determination in materials by 18O(p,αγ)15N nuclear reaction

    Science.gov (United States)

    Kumar, Sanjiv; Sunitha, Y.; Reddy, G. L. N.; Sukumar, A. A.; Ramana, J. V.; Sarkar, A.; Verma, Rakesh

    2016-07-01

    The paper presents a proton induced γ-ray emission method based on 18O(p,αγ)15N nuclear reaction to determine bulk oxygen in materials. The determination involves the measurement of 5.27 MeV γ-rays emitted following the de-excitation of 15N nuclei. A description of the energetics of the reaction is given to provide an insight into the origin of 5.27 MeV γ-rays. In addition, thick target γ-ray yields and the limits of detection are measured to ascertain the analytical potential of the reaction. The thick-target γ-ray yields are measured with a high purity germanium detector and a bismuth germanate detector at 0° as well as 90° angles in 3.0-4.2 MeV proton energy region. The best limit of detection of about 1.3 at.% is achieved at 4.2 MeV proton energy for measurements at 0° as well 90° angles with the bismuth germanate detector while the uncertainty in quantitative analysis is methodology is demonstrated by determining oxygen in several oxide as well as non-oxide materials.

  16. Isospin transport and reaction mechanism in nuclear reactions in the range 20-40 MeV/n

    Science.gov (United States)

    Barlini, S.; Piantelli, S.; Casini, G.; Olmi, A.; Bini, M.; Pasquali, G.; Poggi, G.; Stefanini, A. A.; Bougault, R.; Bonnet, E.; Borderie, B.; Chibhi, A.; Frankland, J. D.; Gruyer, D.; Lopez, O.; Le Neindre, N.; Parlog, M.; Rivet, M. F.; Vient, E.; Rosato, E.; Vigilante, M.; Bruno, M.; Marchi, T.; Morelli, L.; Cinausero, M.; Degerlier, M.; Gramegna, F.; Kozik, T.; Twarog, T.; Fabris, D.; Valdré, S.; Pastore, G.

    2015-10-01

    In recent years, many efforts have been devoted to the investigation of the isospin degree of freedom in nuclear reactions. Comparing systems involving partners with different N/Z, it has been possible to investigate the isospin transport process and its influence on the final products population. This can be then related to the symmetry energy term of the nuclear EOS. From the experimental point of view, this task requires detectors able to measure both charge and mass of the emitted products, in the widest possible range of energy and size of the fragments. With this objective, the FAZIA and GARFIELD+RCo apparatus have been used with success in some recent experiments.

  17. Isospin transport and reaction mechanism in nuclear reactions in the range 20–40 MeV/n

    Energy Technology Data Exchange (ETDEWEB)

    Barlini, S., E-mail: barlini@fi.infn.it; Piantelli, S.; Casini, G.; Olmi, A.; Bini, M.; Pasquali, G.; Poggi, G.; Stefanini, A. A.; Valdré, S.; Pastore, G. [Dipartimento di Fisica ed Astronomia dell’Università and INFN Sezione di Firenze, Firenze (Italy); Bougault, R.; Lopez, O.; Le Neindre, N.; Parlog, M.; Vient, E. [LPC, IN2P3-CNRS, ENSICAEN et Université de Caen, F-14050 Caen-Cedex (France); Bonnet, E.; Chibhi, A.; Frankland, J. D. [GANIL, CEA/DSM-CNRS/IN2P3, B.P.5027, F-14076 Caen cedex (France); Borderie, B.; Rivet, M. F. [Institut de Physique Nucléaire, CNRS/IN2P3, Université Paris-Sud 11, F-91406 Orsay cedex (France); and others

    2015-10-15

    In recent years, many efforts have been devoted to the investigation of the isospin degree of freedom in nuclear reactions. Comparing systems involving partners with different N/Z, it has been possible to investigate the isospin transport process and its influence on the final products population. This can be then related to the symmetry energy term of the nuclear EOS. From the experimental point of view, this task requires detectors able to measure both charge and mass of the emitted products, in the widest possible range of energy and size of the fragments. With this objective, the FAZIA and GARFIELD+RCo apparatus have been used with success in some recent experiments.

  18. LDRD Final Report: Surrogate Nuclear Reactions and the Origin of the Heavy Elements (04-ERD-057)

    Energy Technology Data Exchange (ETDEWEB)

    Escher, J E; Bernstein, L A; Bleuel, D; Burke, J; Church, J A; Dietrich, F S; Forssen, C; Gueorguiev, V; Hoffman, R D

    2007-02-23

    Research carried out in the framework of the LDRD project ''Surrogate Nuclear Reactions and the Origin of the Heavy Elements'' (04-ERD-057) is summarized. The project was designed to address the challenge of determining cross sections for nuclear reactions involving unstable targets, with a particular emphasis on reactions that play a key role in the production of the elements between Iron and Uranium. This report reviews the motivation for the research, introduces the approach employed to address the problem, and summarizes the resulting scientific insights, technical findings, and related accomplishments.

  19. Nuclear excitations and reaction mechanisms. Progress report, 1 November 1979-30 September 1980

    International Nuclear Information System (INIS)

    Among the topics investigated were the following: photon scattering and consistency condition between seagull quadrupole terms and the absorption sum rule; Raman scattering to negative-parity states; nonlocal terms due to exchange and retardation effects in charge-transfer reactions; consistency and meaning of various approximate channel coupling array equations; derivation of equations used in empirical nuclear reaction analyses; multicluster, n-particle scattering theory; converged molecular bound state calculations; consistency of approximate channel coupling array equations; derivations of equations used in empirical nuclear reaction analyses; and WKB-type approximation in angular momenta for central potentials. References to publications are given

  20. Report on the 9. IAEA consultants' meeting of the nuclear reaction data centres

    International Nuclear Information System (INIS)

    This report summarizes the 1987 co-ordination meeting of the national and regional nuclear reaction data centers, convened by the IAEA at regular intervals. The main topics are: the international exchange of nuclear reaction data by means of the ''EXFOR'' system, and the further development of this system; the ''CINDA'' system as an international index and bibliography to neutron reaction data; the sharing of the workload for speedy and reliable data compilation; the exchange and documentation of evaluated data libraries in ENDF format, with the goal of rendering data center services to data users in IAEA Member States by means of computer retrievals and printed materials. (author). Refs, figs and tabs

  1. Dependence of X-Ray Burst Models on Nuclear Reaction Rates

    Science.gov (United States)

    Cyburt, R. H.; Amthor, A. M.; Heger, A.; Johnson, E.; Keek, L.; Meisel, Z.; Schatz, H.; Smith, K.

    2016-10-01

    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.

  2. Nuclear reaction mechanisms. Progress report, June 1975--May 1976

    Energy Technology Data Exchange (ETDEWEB)

    Blann, M.

    1976-01-01

    Research under the subject contract has been directed along two major lines: (1) development and exploration of pre-equilibrium statistical models; (2) experimental measurement and theoretical investigation of heavy ion reaction mechanisms, with emphasis on the limits on compound nucleus formation. Much of the work under this contract has been published and a list of publications is part of this report. This work is not otherwise summarized herein. New unpublished results on heavy ion reactions are briefly summarized, as are results of precompound ..cap alpha.. emission. Colloquia and addresses are also summarized. Separate abstracts appear in ERA for six of the papers in this report.

  3. Analysis of archaeological pieces with nuclear techniques

    International Nuclear Information System (INIS)

    In this work nuclear techniques such as Neutron Activation Analysis, PIXE, X-ray fluorescence analysis, Metallography, Uranium series, Rutherford Backscattering for using in analysis of archaeological specimens and materials are described. Also some published works and thesis about analysis of different Mexican and Meso american archaeological sites are referred. (Author)

  4. Safety analysis of nuclear power plants

    International Nuclear Information System (INIS)

    A study about the safety analysis of nuclear power plant, giving emphasis to how and why to do is presented. The utilization of the safety analysis aiming to perform the licensing requirements is discussed, and an example of the Angra 2 and 3 safety analysis is shown. Some presented tendency of the safety analysis are presented and examples are shown.(E.G.)

  5. Neutrino nuclear responses for double beta decays and astro neutrinos by charge exchange reactions

    Science.gov (United States)

    Ejiri, Hiroyasu

    2014-09-01

    Neutrino nuclear responses are crucial for neutrino studies in nuclei. Charge exchange reactions (CER) are shown to be used to study charged current neutrino nuclear responses associated with double beta decays(DBD)and astro neutrino interactions. CERs to be used are high energy-resolution (He3 ,t) reactions at RCNP, photonuclear reactions via IAR at NewSUBARU and muon capture reactions at MUSIC RCNP and MLF J-PARC. The Gamow Teller (GT) strengths studied by CERs reproduce the observed 2 neutrino DBD matrix elements. The GT and spin dipole (SD) matrix elements are found to be reduced much due to the nucleon spin isospin correlations and the non-nucleonic (delta isobar) nuclear medium effects. Impacts of the reductions on the DBD matrix elements and astro neutrino interactions are discussed.

  6. Low-energy nuclear reactions with hydrogen isotopes

    International Nuclear Information System (INIS)

    Using the Los Alamos Low-Energy Fusion Cross-Section Facility (LEFCS), we have completed the study of the D(t,α)n reaction from E/sub t/ = 12.5 to 117 keV, and now have measured angular distributions of the reactions D(d,p)T and D(d,3He)n from E/sub d/ = 20 to 117 keV. The experimental equipment features a windowless cryogenic target, a precision beam-intensity calorimeter, a 10- to 120-keV accelerator producing negative tritium ins, an accurate target gas-flow and temperature system, and a tritium gas-handling system. Most of the quite anisotropic angular distributions of the D + D reactions have relative errors of about 1% and the integrated cross sections have absolut errors of about 1.5%. Astrophysical S functions extracted from the data and also from a least-squares fit of a + b cos2theta to the data show a curious behavior with energy. The cross sections, which agree with previous but less accurate data, are compared with R-Matrix calculations. We also show preliminary results for alpha-particle spectra of the T(t,α)nn reaction. A feature of this experiment is the flow through our windowless target of 1.5 standard liters of tritium gas per day

  7. DPA calculation for the D-D nuclear fusion reaction in the KSTAR PFC

    International Nuclear Information System (INIS)

    The interactions of fusion reaction products such as 2.45-MeV and 14.06-MeV neutrons and 3.05-MeV protons with the KSTAR PFC (plasma facing component) are analyzed using Monte Carlo codes. The dpa (displacement per atom) values in the three-layered PFC of graphite, Cu, and SS316L are calculated, and the depth profile was analyzed for different-type secondary particles. The PHITS code was used for this study. The deposited energy was also calculated for analysis of the nuclear heating effect. The serious irradiation condition of the International Thermonuclear Experimental Reactor (ITER) parameter, a neutron flux of 3.5 x 1013 neutrons/cm2·sec, was applied. The dpa values during one year operation were estimated as 0.75 dpa for graphite, 4.57 dpa for Cu, and 2.69 dpa for SS316L.

  8. High energy halogen atom reactions activated by nuclear transformations

    International Nuclear Information System (INIS)

    This program, which has been supported for twenty-four years by the Us Atomic Energy Commission and its successor agencies, has produced significant advances in the understanding of the mechanisms of chemical activation by nuclear processes; the stereochemistry of radioactivity for solution of specific problems. This program was contributed to the training of approximately seventy scientists at various levels. This final report includes a review of the areas of research and chronological tabulation of the publications

  9. Isovector spin observables in nuclear charge reactions at LAMPF

    International Nuclear Information System (INIS)

    LAMPF has undertaken a major development program to upgrade facilities for nuclear charge-exchange studies at intermediate energies. The major components of this upgrade are a medium-resolution spectrometer and neutron time-of-flight system for good resolution (δ E < 1 MeV) charge-exchange perograms in (n,p) and (p,n) respectively. Major emphasis is placed on polarization phenomena using polarized beams and analyzing the polarization of the outgoing particle

  10. Nuclear reaction mechanisms. Progress report, June 1976--July 1977

    Energy Technology Data Exchange (ETDEWEB)

    Blann, M.

    1977-01-01

    Research under the subject contract is on heavy ion induced reactions, both on experimental measurement and theoretical interpretation. Measurements have included determination of elastic scattering, evaporation residue, fission, quasi elastic and deep inelastic scattering cross sections. From these data we have extracted information on fusion barrier heights and radii, nucleus-nucleus potentials and fission parameterizations at high angular momenta. We have started investigating influence of excitation energies on inverse cross sections and of precompound decay in heavy ion reactions, and have investigated multidimensional potential energy surfaces for heavy ion collisions. Work which has been published is listed in the Publications Section; work not yet published and/or in progress is discussed herein.

  11. Stochastic aspects of multiparticle production in relativistic nuclear reactions

    International Nuclear Information System (INIS)

    Midrapidity multiparticle production process in ordinary hadron and heavy-ion induced reactions at sufficiently high incident energies are analyzed. It is shown that stochastic aspects of multiparticle production process in relativistic range plays a dominating role in understanding the observable phenomena. The basic idea and the main results of the multisource model for hadron-nucleus and nucleus-nucleus collisions are shown. The concept of the NES (number of effective sources) scaling is discussed. 16 refs.; 7 figs

  12. Reaction kinetic analysis of reactor surveillance data

    Energy Technology Data Exchange (ETDEWEB)

    Yoshiie, T., E-mail: yoshiie@rri.kyoto-u.ac.jp [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka-fu 590-0494 (Japan); Sato, K.; Xu, Q. [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka-fu 590-0494 (Japan); Nagai, Y. [The Oarai Center, Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan)

    2015-06-01

    In reactor pressure vessel surveillance data, it was found that the concentration of matrix defects was very low even after nearly 40 years of operation, though a large number of precipitates existed. In this paper, defect structures obtained from surveillance data of A533B (high Cu concentration) were simulated using reaction kinetic analysis with 11 rate equations. The coefficients used in the equations were quite different from those obtained by fitting a Fe-0.6 wt%Cu alloy irradiated by the Kyoto University Reactor. The difference was mainly caused by alloying elements in A533B, and the effect of alloying elements was extracted. The same code was applied to low-Cu A533B irradiated with high irradiation damage rate, and the formation of voids was correctly simulated.

  13. Study of Nuclear Reactions with 11C and 15O Radioactive Ion Beams

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dongwon [Univ. of California, Berkeley, CA (United States)

    2007-05-14

    Nuclear reaction study with radioactive ion beams is one of the most exciting research topics in modern nuclear physics. The development of radioactive ion beams has allowed nuclear scientists and engineers to explore many unknown exotic nuclei far from the valley of nuclear stability, and to further our understanding of the evolution of the universe. The recently developed radioactive ion beam facility at the Lawrence Berkeley National Laboratory's 88-inch cyclotron is denoted as BEARS and provides 11C, 14O and 15O radioactive ion beams of high quality. These moderate to high intensity, proton-rich radioactive ion beams have been used to explore the properties of unstable nuclei such as 12N and 15F. In this work, the proton capture reaction on 11C has been evaluated via the indirect d(11C, 12N)n transfer reaction using the inverse kinematics method coupled with the Asymptotic Normalization Coefficient (ANC) theoretical approach. The total effective 12N → 11C+p ANC is found to be (C eff12N = 1.83 ± 0.27 fm-1. With the high 11C beam intensity available, our experiment showed excellent agreement with theoretical predictions and previous experimental studies. This study also indirectly confirmed that the 11C(p,γ) reaction is a key step in producing CNO nuclei in supermassive low-metallicity stars, bypassing the slow triple alpha process. The newly developed 15O radioactive ion beam at BEARS was used to study the poorly known level widths of 16F via the p(15O,15O)p reaction. Among the nuclei in the A=16, T=1 isobaric triad, many states in 16N and 16O have been well established, but less has been reported on 16F. Four states of 16F below 1 MeV have been identified experimentally: 0-, 1

  14. Economic Analysis of Nuclear Energy

    International Nuclear Information System (INIS)

    This study consists of various issues as follows; electricity price regulation in the liberalized electricity market, establishment of carbon emission limit in national electricity sector, the role of nuclear power as an future energy supply option, the future prospect of CO2 capture and sequestration and current research status of that area in Korea, and Preliminary economic feasibility study of MIP(Medical Isotopes Producer). In the price regulation in the liberalized electricity market, the characteristic of liberalized electricity market in terms of regulation was discussed. The current status and future projection of GHG emission in Korean electricity sector was also investigated. After that, how to set the GHG emission limit in the national electricity sector was discussed. The characteristic of nuclear technology and the research in progress were summarized with the suggestion of the possible new application of nuclear power. The current status and future prospect of the CO2 capture and sequestration research was introduced and current research status of that area in Korea was investigated. Preliminary economic feasibility study of MIP(Medical Isotopes Producer), using liquid nuclear fuel to produce medical isotopes of Mo-99 and Sr-89, was performed

  15. Investigations of nuclear structure and nuclear reactions induced by complex projectiles. Progress report, September 1, 1991--August 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Sarantites, D.G.

    1992-12-01

    The research program described touches five areas of nuclear physics: nuclear structure studies at high spin (hyperdeformation in the mass A {approx_equal} 182 region, structure of {sup 182}Hg and {sup 182}Au at high spin, a highly deformed band in {sup 136}Pm and the anomalous h{sub 11/2} proton crossing in the A{approximately}135 superdeformed region), studies at the interface between structure and reactions (population of entry states in heavy-ion fusion reactions, nuclear structure effects in proton evaporation spectra, nuclear structure- dependent entry state population by total spectroscopy, entrance channel effects in fusion near the barrier, lifetimes of subbarrier {alpha} particles by the atomic clock method), production and study of hot nuclei (the statistical model evaporation code EVAP, statistical emission of deuterons and tritons from highly excited compound nuclei, heavy-fragment emission as a probe of the thermal properties of highly excited compound nuclei, use of incoming-wave boundary condition transmission coefficients in the statistical model: implications in the particle evaporation spectra, study of transparency in the optical model), reaction mechanism studies (binary character of highly dissipative {sup 209}Bi + {sup 136}Xe collisions at E/A=28.2 MeV), and development and use of novel techniques and instrumentation in these areas of research (including a 4{pi} channel selection device, a novel x-ray detector, and a simple channel-selecting detector).

  16. Investigations of nuclear structure and nuclear reactions induced by complex projectiles. [Dept. of Chemistry, Washington Univ. , St. Louis, Mo

    Energy Technology Data Exchange (ETDEWEB)

    Sarantites, D.G.

    1992-01-01

    The research program described touches five areas of nuclear physics: nuclear structure studies at high spin (hyperdeformation in the mass A [approx equal] 182 region, structure of [sup 182]Hg and [sup 182]Au at high spin, a highly deformed band in [sup 136]Pm and the anomalous h[sub 11/2] proton crossing in the A[approximately]135 superdeformed region), studies at the interface between structure and reactions (population of entry states in heavy-ion fusion reactions, nuclear structure effects in proton evaporation spectra, nuclear structure- dependent entry state population by total spectroscopy, entrance channel effects in fusion near the barrier, lifetimes of subbarrier [alpha] particles by the atomic clock method), production and study of hot nuclei (the statistical model evaporation code EVAP, statistical emission of deuterons and tritons from highly excited compound nuclei, heavy-fragment emission as a probe of the thermal properties of highly excited compound nuclei, use of incoming-wave boundary condition transmission coefficients in the statistical model: implications in the particle evaporation spectra, study of transparency in the optical model), reaction mechanism studies (binary character of highly dissipative [sup 209]Bi + [sup 136]Xe collisions at E/A=28.2 MeV), and development and use of novel techniques and instrumentation in these areas of research (including a 4[pi] channel selection device, a novel x-ray detector, and a simple channel-selecting detector).

  17. Dynamical Behavior of Core 3 He Nuclear Reaction-Diffusion Systems and Sun's Gravitational Field

    Institute of Scientific and Technical Information of China (English)

    DU Jiulin; SHEN Hong

    2005-01-01

    The coupling of the sun's gravitational field with processes of diffusion and convection exerts a significant influence on the dynamical behavior of the core 3He nuclear reaction-diffusion system. Stability analyses of the system are made in this paper by using the theory of nonequilibrium dynamics. It is showed that, in the nuclear reaction regions extending from the center to about 0.38 times of the radius of the sun, the gravitational field enables the core 3He nuclear reaction-diffusion system to become unstable and, after the instability, new states to appear in the system have characteristic of time oscillation. This may change the production rates of both 7Be and 8B neutrinos.

  18. Entrance channel effects in fusion reactions near the barrier: Reaction dynamics or nuclear structure?

    International Nuclear Information System (INIS)

    The origin of previously reported entrance channel effects by symmetric and asymmetric fusion reactions leading to rare earth nuclei near the Coulomb barrier is critically reviewed. Possible influences of reaction dynamics or structure effects due to the proximity of superdeformation are discussed using new charged-particle spectra and angular distributions associated with specific axn exit channels. For axn channels, nonstatistical effects in the fusion of the asymmetric entrance channel are responsible for the large difference in the spin distributions in the evaporation residues formed by symmetric and asymmetric entrance channels. Whereas GDR spectra show significant entrance channel effects, the authors find no influence on the subbarrier α spectra from possible elongated shapes associated with early reaction dynamics. New data and analyses of γ-ray multiplicity distributions from the xn exit channels show that previously reported entrance channel effects are due to mapping from l to residue spin and then to γ-ray multiplicity

  19. Activation cross sections of $\\alpha$-particle induced nuclear reactions on hafnium and deuteron induced nuclear reaction on tantalum: production of $^{178}$W/$^{178m}$Ta generator

    CERN Document Server

    Tárk'anyi, F; Ditrói, F; Hermanne, A; Ignatyuk, A V; Uddin, M S

    2014-01-01

    In the frame of a systematic study of charged particle production routes of medically relevant radionuclei, the excitation function for indirect production of $^{178m}$Ta through $^{nat}$Hf($\\alpha$,xn)$^{178}$W-$^{178m}$Ta nuclear reaction was measured for the first time up to 40 MeV. In parallel, the side reactions $^{nat}$Hf($\\alpha$,x)$^{179,177,176,175}$W, $^{183,182,178g,177,176,175}$Ta, $^{179m,177m,175}$Hf were also assessed. Stacked foil irradiation technique and $\\gamma$-ray spectrometry were used. New experimental cross section data for the $^{nat}$Ta(d,xn)$^{178}$W reaction are also reported up to 40 MeV. The measured excitation functions are compared with the results of the ALICE-IPPE, and EMPIRE nuclear reaction model codes and with the TALYS 1.4 based data in the TENDL-2013 library. The thick target yields were deduced and compared with yields of other charged particle ((p,4n), (d,5n) and ($^3$He,x)) production routes for $^{178}$W.

  20. Dependence of X-Ray Burst Models on Nuclear Reaction Rates

    OpenAIRE

    Cyburt, R. H.; Amthor, A. M.; Heger, A.; Johnson, E.; Keek, L.; Meisel, Z.; Schatz, H.; Smith, K

    2016-01-01

    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,$\\gamma$), ($\\alpha$,$\\gamma$), and ($\\alpha$,p) nuclear reaction rates using fully self-consistent burst models that account for the feedbacks between changes in nuclear energy generation and changes in astrophy...

  1. Report on the IAEA technical meeting on network of nuclear reaction data centres

    International Nuclear Information System (INIS)

    An IAEA Technical Meeting on the Network of Nuclear Reaction Data Centres (and the biennial Data Centre Heads' Meeting) was held at the OECD Nuclear Energy Agency, Issy-les-Moulineaux (near Paris), France, from 27 to 30 May 2002. The meeting was attended by 21 participants from 12 co-operating data centres of six Member States and two international organizations. This report contains the meeting summary, conclusions and actions, status reports of the participating data centres, and working papers considered. (author)

  2. Autoclave nuclear criticality safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    D`Aquila, D.M. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States); Tayloe, R.W. Jr. [Battelle, Columbus, OH (United States)

    1991-12-31

    Steam-heated autoclaves are used in gaseous diffusion uranium enrichment plants to heat large cylinders of UF{sub 6}. Nuclear criticality safety for these autoclaves is evaluated. To enhance criticality safety, systems are incorporated into the design of autoclaves to limit the amount of water present. These safety systems also increase the likelihood that any UF{sub 6} inadvertently released from a cylinder into an autoclave is not released to the environment. Up to 140 pounds of water can be held up in large autoclaves. This mass of water is sufficient to support a nuclear criticality when optimally combined with 125 pounds of UF{sub 6} enriched to 5 percent U{sup 235}. However, water in autoclaves is widely dispersed as condensed droplets and vapor, and is extremely unlikely to form a critical configuration with released UF{sub 6}.

  3. Nuclear Reaction Rates in a Plasma The Effect of Highly Damped Modes

    CERN Document Server

    Opher, M; Opher, Merav; Opher, Reuven

    2000-01-01

    The fluctuation-dissipation theorem is used to evaluate the screening factor of nuclear reactions due to the electromagnetic fluctuations in a plasma. We show that the commonly used Saltpeter factor is obtained if only fluctuations near the plasma eigenfrequency are assumed to be important (\\omega \\sim \\omega_{pe}\\ll T (\\hbar=k_{B}=1)). By taking into account all the fluctuations, the highly damped ones, with \\omega >\\omega_{pe}, as well as those with \\omega\\leq\\omega_{pe}, we find that nuclear reaction rates are higher than those obtained using the Saltpeter factor, for many interesting plasmas.

  4. Nuclear fusion reactions involving weakly bound nuclei at near barrier energies

    International Nuclear Information System (INIS)

    The studies on nuclear fusion reactions involving loosely bound nuclei around barrier energies have attracted significant attention since last almost three decades. One of the primary aim of these studies is to investigate the role of unique characteristics features of nuclei lying in the close vicinity of drip lines in determination of the fusion cross section. The static effects arising because of large spatial extension of some highly neutron-rich or proton-rich nuclear isotopes have been found to enhance the fusion cross section due to barrier lowering. However regarding the role of various channel coupling dynamical effects in the description of fusion reactions conflicting results have been observed

  5. Chemical modeling of irreversible reactions in nuclear waste-water-rock systems

    International Nuclear Information System (INIS)

    Chemical models of aqueous geochemical systems are usually built on the concept of thermodynamic equilibrium. Though many elementary reactions in a geochemical system may be close to equilibrium, others may not be. Chemical models of aqueous fluids should take into account that many aqueous redox reactions are among the latter. The behavior of redox reactions may critically affect migration of certain radionuclides, especially the actinides. In addition, the progress of reaction in geochemical systems requires thermodynamic driving forces associated with elementary reactions not at equilibrium, which are termed irreversible reactions. Both static chemical models of fluids and dynamic models of reacting systems have been applied to a wide spectrum of problems in water-rock interactions. Potential applications in nuclear waste disposal range from problems in geochemical aspects of site evaluation to those of waste-water-rock interactions. However, much further work in the laboratory and the field will be required to develop and verify such applications of chemical modeling

  6. Recent research on nuclear reaction using high-energy proton and neutron

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, Tokushi [Tokyo Univ., Tanashi (Japan). Inst. for Nuclear Study

    1997-11-01

    The presently available high-energy neutron beam facilities are introduced. Then some interesting research on nuclear reaction using high-energy protons are reported such as the intermediate mass fragments emission and neutron spectrum measurements on various targets. As the important research using high-energy neutron, the (p,n) reactions on Mn, Fe, and Ni, the elastic scattering of neutrons, and the shielding experiments are discussed. (author)

  7. Cross Sections Calculations of ( d, t) Nuclear Reactions up to 50 MeV

    Science.gov (United States)

    Tel, E.; Yiğit, M.; Tanır, G.

    2013-04-01

    In nuclear fusion reactions two light atomic nuclei fuse together to form a heavier nucleus. Fusion power is the power generated by nuclear fusion processes. In contrast with fission power, the fusion reaction processes does not produce radioactive nuclides. The fusion will not produce CO2 or SO2. So the fusion energy will not contribute to environmental problems such as particulate pollution and excessive CO2 in the atmosphere. Fusion powered electricity generation was initially believed to be readily achievable, as fission power had been. However, the extreme requirements for continuous reactions and plasma containment led to projections being extended by several decades. In 2010, more than 60 years after the first attempts, commercial power production is still believed to be unlikely before 2050. Although there have been significant research and development studies on the inertial and magnetic fusion reactor technology, there is still a long way to go to penetrate commercial fusion reactors to the energy market. In the fusion reactor, tritium self-sufficiency must be maintained for a commercial power plant. Therefore, for self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. Working out the systematics of ( d, t) nuclear reaction cross sections is of great importance for the definition of the excitation function character for the given reaction taking place on various nuclei at different energies. Since the experimental data of charged particle induced reactions are scarce, self-consistent calculation and analyses using nuclear theoretical models are very important. In this study, ( d, t) cross sections for target nuclei 19F, 50Cr, 54Fe, 58Ni, 75As, 89Y, 90Zr, 107Ag, 127I, 197Au and 238U have been investigated up to 50 MeV deuteron energy. The excitation functions for ( d, t) reactions have been calculated by pre-equilibrium reaction mechanism. Calculation results have been also compared with the available measurements in

  8. Nuclear Reaction Rate Uncertainties and their effects on Nova Nucleosynthesis Modeling

    OpenAIRE

    Hix, W. Raphael; Smith, Michael S.; Mezzacappa, Anthony; Starrfield, Sumner; Smith, Donald L.

    2001-01-01

    The nucleosynthesis and other observable consequences of a nova outburst depend sensitively on the details of the thermonuclear runaway which initiates the outburst. One important source of uncertainty in our current models is the nuclear reaction data used as input for the evolutionary calculations. We present preliminary results of the first analyses of the impact on nova nucleosynthesis of all reaction rate uncertainties considered simultaneously.

  9. Coulomb interaction effects in many-particle nuclear reactions with two-fragment resonance formation

    International Nuclear Information System (INIS)

    The modified final-state interaction theory taking into consideration the Coulomb interaction between two-fragment nuclear resonance decay products and accompanying reaction products is developed including the case of near-threshold resonances. The branching ratio change is also studied for the near-threshold resonance 7Li*(Ex = 7.45 MeV), which is formed in the reaction 7Li(α,α)7Li*at Eα = 27.2 MeV

  10. Euclidean resonance and a new type of nuclear reactions

    CERN Document Server

    Ivlev, B I

    2003-01-01

    The extremely small probability of quantum tunneling through an almost classical potential barrier may become not small under the action of the specially adapted nonstationary field. The tunneling rate has a sharp peak as a function of the particle energy when it is close to the certain resonant value defined by the nonstationary field (Euclidean resonance). Alpha decay of nuclei has a small probability since the alpha particle should tunnel through a very nontransparent Coulomb barrier. The incident proton, due to the Coulomb interaction with the tunneling alpha particle, plays the role of a nonstationary field which may result in Euclidean resonance in tunneling of the alpha particle. At the resonant proton energy, which is of the order of 0.2 Mev, the alpha particle escapes the nucleus and goes to infinity with no influence of the nuclear Coulomb barrier. The process is inelastic since the alpha particle releases energy and the proton gains it. This stimulation of alpha decay by a proton constitutes a new ...

  11. Consequences of wave function orthogonality for medium energy nuclear reactions

    International Nuclear Information System (INIS)

    In the usual models of high-energy bound-state to continuum transitions no account is taken of the orthogonality of the bound and continuum wave functions. This orthogonality induces considerable cancellations in the overlap integrals expressing the transition amplitudes for reactions such as (e,e'p), (γ,p), and (π,N), which are simply not included in the distorted-wave Born-approximation calculations which to date remain the only computationally feasible heirarchy of approximations. The object of this paper is to present a new formulation of the bound-state to continuum transition problem, based upon flux conservation, in which the orthogonality of wave functions is taken into account ab initio. The new formulation, while exact if exact wave functions are used, offers the possibility of using approximate wave functions for the continuum states without doing violence to the cancellations induced by orthogonality. The method is applied to single-particle states obeying the Schroedinger and Dirac equations, as well as to a coupled-channel model in which absorptive processes can be described in a fully consistent manner. Several types of absorption vertex are considered, and in the (π,N) case the equivalence of pseudoscalar and pseudovector πNN coupling is seen to follow directly from wave function orthogonality

  12. Nuclear Image Analysis Study of Neuroendocrine Tumors

    OpenAIRE

    Park, Meeja; Baek, Taehwa; Baek, Jongho; Son, Hyunjin; Kang, Dongwook; Kim, Jooheon; Lee, Hyekyung

    2012-01-01

    Background There is a subjective disagreement about nuclear chromatin in the field of pathology. Objective values of red, green, and blue (RGB) light intensities for nuclear chromatin can be obtained through a quantitative analysis using digital images. Methods We examined 10 cases of well differentiated neuroendocrine tumors of the rectum, small cell lung carcinomas, and moderately differentiated squamous cell lung carcinomas respectively. For each case, we selected 30 representative cells a...

  13. Low-energy heavy-ion reactions: a link between nuclear structure and reaction dynamics

    CERN Document Server

    Corradi, L; Beghini, S; Lin, C J; Montagnoli, G; Pollarolo, G; Scarlassara, F; Segato, G F; Stefanini, A M; Zheng, L F

    1999-01-01

    High precision data recently obtained in the study of multinucleon transfer and sub-barrier fusion reactions at LNL are presented. The studies of transfer channels in the systems sup 4 sup 0 sup , sup 4 sup 8 Ca+ sup 1 sup 2 sup 4 Sn and sup 6 sup 4 Ni+ sup 2 sup 3 sup 8 U revealed important effects not identified in the past, and demonstrated the possibility of a quantitative understanding of the role played by the various degrees of freedom in the reaction mechanism. Evidence of their influence on the fusion enhancements seem to show-up in the systems sup 4 sup 0 Ca+ sup 1 sup 2 sup 4 sup , sup 1 sup 1 sup 6 Sn and sup 4 sup 0 Ca+ sup 9 sup 0 sup , sup 9 sup 6 Zr, but, in general, the data still escape a consistent treatment.

  14. Nuclear class 1 piping stress analysis

    International Nuclear Information System (INIS)

    A nuclear class 1 piping stress analysis, according to the ASME code, is presented. The TRHEAT computer code has been used to determine the piping wall thermal gradient. The Nupipe computer code was employed for the piping stress analysis. Computer results were compared with the allowable criteria from the ASME code. (Author)

  15. Direct nuclear-pumped lasers using the He-3/n,p/H-3 reaction

    Science.gov (United States)

    Deyoung, R. J.; Jalufka, N. W.; Hohl, F.

    1978-01-01

    A description is presented of experimental results concerning a specific class of direct nuclear-pumped lasers classified as 'volumetric nuclear lasers'. In the considered laser system a fissioning gas, He-3, is mixed with the lasing gas to form a homogeneous mixture, resulting in uniform volume excitation. In typical volumetric nuclear lasers a fast-burst reactor is used as a source of neutrons which penetrate a polyethylene moderator. Here the fast neutrons are thermalized. After thermalization, neutrons scatter into the laser cell. Nuclear reactions produce a proton of 0.56 MeV and a tritium ion of 0.19. These ions produce secondary electrons which pump the laser medium creating a population inversion. The results reported demonstrate direct nuclear pumping of He-3-Ar, Xe, Kr, and Cl with the considered system.

  16. Reaction path analysis of sodium-water chemical reaction field using laser diagnostics

    International Nuclear Information System (INIS)

    In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. Therefore, the study on sodium-water chemical reactions is of importance for security reasons. This study aims to clarify the gas phase sodium-water reaction path and reaction products. Na, Na2, H2O, and reaction products in the counter-flow sodium-water reaction field were measured using laser diagnostics such as Raman scattering and photo-fragmentation. The main product in the sodium-water reaction was determined to be NaOH and its reaction path was discussed using Na-H2O elementally reaction analysis. (author)

  17. The ``light-est'' of all Projectiles: Nuclear Structure Studies Using Photonuclear Reactions

    Science.gov (United States)

    Pietralla, Norbert

    2014-03-01

    Nuclear reactions induced by photons have had and continue to have a large impact on the course of nuclear physics. Photons interact purely electromagnetically with the atomic nucleus and induce minimal momentum transfer at given excitation energy. Photonuclear reaction processes can be expanded in terms of QED and photonuclear excitations are by far dominated by one-step processes. They allow for a model independent measurement of nuclear observables and, hence, for a clean characterization of effective nuclear forces. Apart from the pioneering photonuclear reactions by Bothe and Gentner in the 1930s, bremsstrahlung has been used most widely as an intense source of gamma-rays for photonuclear reactions from the 1940s until today. The nuclear dipole strength distribution has largely been mapped out at bremsstrahlung facilities. While the continuous-energy distribution of bremsstrahlung photons offers a complete view of the spectrum of photonuclear excitations, it suffers from a poor sensitivity to specific energy intervals. Intense, energy-tunable, quasi-monochromatic gamma-ray beams from laser-Compton backscattering processes have revolutionized the field of photonuclear reactions for the last ten years. A set of new techniques is under development and new information on fundamental nuclear modes, such as the IVGDR, IVGQR, Pygmy Dipole Resonance, and the Scissors Mode, has recently been obtained. We will attempt to give a brief overview of the state of the art and dare an outlook at the research opportunities at the next generation of gamma-ray facilities under construction in the U.S. and Europe. Supported by the DFG under grant No. SFB634.

  18. Analysis of cross sections using various nuclear potential

    International Nuclear Information System (INIS)

    The relevant astrophysical reaction rates which are derived from the reaction cross sections are necessary input to the reaction network. In this work, we analyse several theoretical models of the nuclear potential which give better prediction of the cross sections for some selected reactions

  19. Economic analysis of nuclear reactors

    International Nuclear Information System (INIS)

    The report presents several methods for estimating the power costs of nuclear reactors. When based on a consistent set of economic assumptions, total power costs may be useful in comparing reactor alternatives. The principal items contributing to the total power costs of a nuclear power plant are: (1) capital costs, (2) fuel cycle costs, (3) operation and maintenance costs, and (4) income taxes and fixed charges. There is a large variation in capital costs and fuel expenses among different reactor types. For example, the standard once-through LWR has relatively low capital costs; however, the fuel costs may be very high if U3O8 is expensive. In contrast, the FBR has relatively high capital costs but low fuel expenses. Thus, the distribution of expenses varies significantly between these two reactors. In order to compare power costs, expenses and revenues associated with each reactor may be spread over the lifetime of the plant. A single annual cost, often called a levelized cost, may be obtained by the methods described. Levelized power costs may then be used as a basis for economic comparisons. The paper discusses each of the power cost components. An exact expression for total levelized power costs is derived. Approximate techniques of estimating power costs will be presented

  20. Uncovering Special Nuclear Materials by Low-energy Nuclear Reaction Imaging

    OpenAIRE

    P. B. Rose; Erickson, A. S.; Mayer, M.; Nattress, J.; Jovanovic, I

    2016-01-01

    Weapons-grade uranium and plutonium could be used as nuclear explosives with extreme destructive potential. The problem of their detection, especially in standard cargo containers during transit, has been described as “searching for a needle in a haystack” because of the inherently low rate of spontaneous emission of characteristic penetrating radiation and the ease of its shielding. Currently, the only practical approach for uncovering well-shielded special nuclear materials is by use of act...

  1. High energy nuclear reactions ('Spallation') and their application in calculation of the Acceleration Driven Systems (ADS)

    International Nuclear Information System (INIS)

    This work presents a study of high energy nuclear reactions which are fundamental to dene the source term in accelerator driven systems. These nuclear reactions, also known as spallation, consist in the interaction of high energetic hadrons with nucleons in the atomic nucleus. The phenomenology of these reactions consist in two step. In the rst, the proton interacts through multiple scattering in a process called intra-nuclear cascade. It is followed by a step in which the excited nucleus, coming from the intranuclear cascade, could either, evaporates particles to achieve a moderate energy state or fission. This process is known as competition between evaporation and fission. In this work the main nuclear models, Bertini and Cugnon are reviewed, since these models are fundamental for design purposes of the source term in ADS, due to lack of evaluated nuclear data for these reactions. The implementation and validation of the calculation methods for the design of the source is carried out to implement the methodology of source design using the program MCNPX (Monte Carlo N-Particle eXtended), devoted to calculation of transport of these particles and the validation performed by an international cooperation together with a Coordinated Research Project (CRP) of the International Atomic Energy Agency and available jobs, in order to qualify the calculations on nuclear reactions and the de-excitation channels involved, providing a state of the art of design and methodology for calculating external sources of spallation for source driven systems. The CRISP, is a brazilian code for the phenomenological description of the reactions involved and the models implemented in the code were reviewed and improved to continue the qualification process. Due to failure of the main models in describing the production of light nuclides, the multifragmentation reaction model was studied. Because the discrepancies in the calculations of production of these nuclides are attributes to the

  2. Nuclear Matter Incompressibility Effect on the Cross Section of Fusion Reactions with a weakly bound projectile

    CERN Document Server

    Seyyedi, S A

    2015-01-01

    Fusion reactions with a weakly bound projectile are studied using the double-folding model along with a repulsive interaction modifying term. Using this modified potential, including nuclear matter incompressibility effects, the fusion reaction cross sections and suppression parameters are calculated for 9Be +209Bi,208Pb,29Si and 27Al reactions. The results show that applying these effects at energies near the Coulomb barrier improves the agreement between the calculated and experimental cross sections, and modifies the mean values of the suppression parameter.

  3. Presentation of a reference material for the spatially resolved hydrogen analytics in near-surface layers by means of nuclear-reaction analysis; Darstellung eines Referenzmaterials fuer die ortsaufgeloeste Wasserstoffanalytik in oberflaechennahen Schichten mittels Kernreaktionsanalyse

    Energy Technology Data Exchange (ETDEWEB)

    Reinholz, U.

    2005-10-03

    The object of the thesis is the presentation of the theory of the {sup 15}N-reaction analysis (NRA), the experiemental construction of the corresponding beam pipe at the ion accelerator of the BAM and the evaluation of the measurement results. The aim is the first characterization of a reference material for the H analytics on the base of amorphous silicon (aSi) on a Si[100] substrate. The homogeneity of the aSi:H layers deposited by means of CVD was studied. For this pro substrate for about 30 samples the hydrogen depth profiles were measures, folded by means of a program created within the thesis and subjected to a statistical evaluation. The result were mean value ans standard deviation of the hydrogen concentration as well as an estimator for the contribution of the inhomogeneity to the measurement uncertainty. The stability of the potential reference material was proved by the constancy of result of repeated measurements of the hydrogen concentration during the application of a large dose of {sup 15}N ions. In an international ring experiment the reproducibility of the measurement results was proved. For the characterization of the aSi:H layers beside the NRA the white-light interferometry, ellipsometry, profilometry, and X-ray reflectometry, as well as the IR and Raman spectroscopy were used. The stoichiometry of the applied standard material kapton was checked by means of NMR spectroscopy and CHN analysis.

  4. High sensitivity boron quantification in bulk silicon using the 11B(p,α0)8Be nuclear reaction

    International Nuclear Information System (INIS)

    There is a great need to quantify sub-ppm levels of boron in bulk silicon. There are several methods to analyze B in Si: Nuclear Reaction Analysis using the 11B(p,α0)8Be reaction exhibits a quantification limit of some hundreds ppm of B in Si. Heavy Ion Elastic Recoil Detection Analysis offers a detection limit of 5 to 10 at. ppm. Secondary Ion Mass Spectrometry is the method of choice of the semiconductor industry for the analysis of B in Si. This work verifies the use of NRA to quantify B in Si, and the corresponding detection limits. Proton beam with 1.6 up to 2.6 MeV was used to obtain the cross-section of the 11B(p,α0)8Be nuclear reaction at 170° scattering angle. The results show good agreementwith literature indicating that the quantification of boron in silicon can be achieved at 100 ppm level (high sensitivity) at LAMFI-IFUSP with about 16% uncertainty. Increasing the detection solid angle and the collected beam charge, can reduce the detection limit to less than 100 ppm meeting present technological needs.

  5. Extracting nuclear sizes of medium to heavy nuclei from total reaction cross sections

    Science.gov (United States)

    Horiuchi, W.; Hatakeyama, S.; Ebata, S.; Suzuki, Y.

    2016-04-01

    Background: Proton and neutron radii are fundamental quantities of atomic nuclei. To study the sizes of short-lived unstable nuclei, there is a need for an alternative to electron scattering. Purpose: The recent paper by Horiuchi et al. [Phys. Rev. C 89, 011601(R) (2014)], 10.1103/PhysRevC.89.011601 proposed a possible way of extracting the matter and neutron-skin thickness of light- to medium-mass nuclei using total reaction cross section, σR. The analysis is extended to medium to heavy nuclei up to lead isotopes with due attention to Coulomb breakup contributions as well as density distributions improved by paring correlation. Methods: We formulate a quantitative calculation of σR based on the Glauber model including the Coulomb breakup. To substantiate the treatment of the Coulomb breakup, we also evaluate the Coulomb breakup cross section due to the electric dipole field in a canonical-basis-time-dependent-Hartree-Fock-Bogoliubov theory in the three-dimensional coordinate space. Results: We analyze σR's of 103 nuclei with Z =20 , 28, 40, 50, 70, and 82 incident on light targets, H,21, 4He, and 12C. Three kinds of Skyrme interactions are tested to generate those wave functions. To discuss possible uncertainty due to the Coulomb breakup, we examine its dependence on the target, the incident energy, and the Skyrme interaction. The proton is a most promising target for extracting the nuclear sizes as the Coulomb excitation can safely be neglected. We find that the so-called reaction radius, aR=√{σR/π } , for the proton target is very well approximated by a linear function of two variables, the matter radius and the skin thickness, in which three constants depend only on the incident energy. We quantify the accuracy of σR measurements needed to extract the nuclear sizes. Conclusions: The proton is the best target because, once the incident energy is set, its aR is very accurately determined by only the matter radius and neutron-skin thickness. If σR's at

  6. Summary report on [IAEA] technical meeting of the International Network of Nuclear Reaction Data Centres

    International Nuclear Information System (INIS)

    An IAEA Technical Meeting of the International Network of Nuclear Reaction Data Centres was held at the IAEA Headquarters in Vienna from 25 to 26 May 2009. The meeting was attended by 23 participants from 13 cooperating data centres. A summary of the meeting is given in this report, along with the conclusions, actions, and status report of the participating data centres. (author)

  7. Nuclear reactions in astrophysics: Recent experimental and theoretical studies, and further quests

    Energy Technology Data Exchange (ETDEWEB)

    Arnould, M. (Inst. d' Astronomie et d' Astrophysique, Univ. Libre, Brussels (Belgium))

    1992-03-09

    A brief review is presented of recent theoretical and experimental efforts that have led to an improvement in our knowledge of nuclear reaction rates of interest in astrophysics. Emphasis is also put on the still existing (sometimes very large) uncertainties that affect some important rates. This is especially the case when short-lived nuclei are involved in the entrance channel. (orig.).

  8. Quantum, Multi-Body Effects and Nuclear Reaction Rates in Plasmas

    OpenAIRE

    Savchenko, V. I.

    2000-01-01

    Detailed calculations of the contribution from off-shell effects to the quasiclassical tunneling of fusing particles are provided. It is shown that these effects change the Gamow rates of certain nuclear reactions in dense plasma by several orders of magnitude.

  9. Assessment and Requirements of Nuclear Reaction Databases for GCR Transport in the Atmosphere and Structures

    Science.gov (United States)

    Cucinotta, F. A.; Wilson, J. W.; Shinn, J. L.; Tripathi, R. K.

    1998-01-01

    The transport properties of galactic cosmic rays (GCR) in the atmosphere, material structures, and human body (self-shielding) am of interest in risk assessment for supersonic and subsonic aircraft and for space travel in low-Earth orbit and on interplanetary missions. Nuclear reactions, such as knockout and fragmentation, present large modifications of particle type and energies of the galactic cosmic rays in penetrating materials. We make an assessment of the current nuclear reaction models and improvements in these model for developing required transport code data bases. A new fragmentation data base (QMSFRG) based on microscopic models is compared to the NUCFRG2 model and implications for shield assessment made using the HZETRN radiation transport code. For deep penetration problems, the build-up of light particles, such as nucleons, light clusters and mesons from nuclear reactions in conjunction with the absorption of the heavy ions, leads to the dominance of the charge Z = 0, 1, and 2 hadrons in the exposures at large penetration depths. Light particles are produced through nuclear or cluster knockout and in evaporation events with characteristically distinct spectra which play unique roles in the build-up of secondary radiation's in shielding. We describe models of light particle production in nucleon and heavy ion induced reactions and make an assessment of the importance of light particle multiplicity and spectral parameters in these exposures.

  10. A global DGLAP analysis of nuclear PDFs

    Science.gov (United States)

    Eskola, K. J.; Kolhinen, V. J.; Paukkunen, H.; Salgado, C. A.

    2008-05-01

    In this talk, we shortly report results from our recent global DGLAP analysis of nuclear parton distributions. This is an extension of our former EKS98-analysis improved with an automated χ2 minimization procedure and uncertainty estimates. Although our new analysis show no significant deviation from EKS98, a sign of a significantly stronger gluon shadowing could be seen in the RHIC BRAHMS data.

  11. Completing the nuclear reaction puzzle of the nucleosynthesis of 92Mo

    CERN Document Server

    Tveten, G M; Schwengner, R; Naqvi, F; Larsen, A C; Eriksen, T K; Garrote, F L Bello; Bernstein, L A; Bleuel, D L; Campo, L Crespo; Guttormsen, M; Giacoppo, F; Görgen, A; Hagen, T W; Hadynska-Klek, K; Klintefjord, M; Meyer, B S; Nyhus, H T; Renstrøm, T; Rose, S J; Sahin, E; Siem, S; Tornyi, T G

    2016-01-01

    One of the greatest questions for modern physics to address is how elements heavier than iron are created in extreme, astrophysical environments. A particularly challenging part of that question is the creation of the so-called p-nuclei, which are believed to be mainly produced in some types of supernovae. The lack of needed nuclear data presents an obstacle in nailing down the precise site and astrophysical conditions. In this work, we present for the first time measurements on the nuclear level density and average strength function of $^{92}$Mo. State-of-the-art p-process calculations systematically underestimate the observed solar abundance of this isotope. Our data provide stringent constraints on the $^{91}$Nb$(p,{\\gamma})^{92}$Mo reaction rate, which is the last unmeasured reaction in the nucleosynthesis puzzle of $^{92}$Mo. Based on our results, we conclude that the $^{92}$Mo abundance anomaly is not due to the nuclear physics input to astrophysical model calculations.

  12. Completing the nuclear reaction puzzle of the nucleosynthesis of 92Mo

    Science.gov (United States)

    Tveten, G. M.; Spyrou, A.; Schwengner, R.; Naqvi, F.; Larsen, A. C.; Eriksen, T. K.; Bello Garrote, F. L.; Bernstein, L. A.; Bleuel, D. L.; Crespo Campo, L.; Guttormsen, M.; Giacoppo, F.; Görgen, A.; Hagen, T. W.; Hadynska-Klek, K.; Klintefjord, M.; Meyer, B. S.; Nyhus, H. T.; Renstrøm, T.; Rose, S. J.; Sahin, E.; Siem, S.; Tornyi, T. G.

    2016-08-01

    One of the greatest questions for modern physics to address is how elements heavier than iron are created in extreme astrophysical environments. A particularly challenging part of that question is the creation of the so-called p -nuclei, which are believed to be mainly produced in some types of supernovae. The lack of needed nuclear data presents an obstacle in nailing down the precise site and astrophysical conditions. In this work, we present for the first time measurements on the nuclear level density and average γ strength function of 92Mo. State-of-the-art p -process calculations systematically underestimate the observed solar abundance of this isotope. Our data provide stringent constraints on the 91Nb(p ,γ )92Mo reaction rate, which is the last unmeasured reaction in the nucleosynthesis puzzle of 92Mo. Based on our results, we conclude that the 92Mo abundance anomaly is not due to the nuclear physics input to astrophysical model calculations.

  13. Further evidence of nuclear reactions in the Pd/D lattice: emission of charged particles.

    Science.gov (United States)

    Szpak, Stanislaw; Mosier-Boss, Pamela A; Gordon, Frank E

    2007-06-01

    Almost two decades ago, Fleischmann and Pons reported excess enthalpy generation in the negatively polarized Pd/D-D2O system, which they attributed to nuclear reactions. In the months and years that followed, other manifestations of nuclear activities in this system were observed, viz. tritium and helium production and transmutation of elements. In this report, we present additional evidence, namely, the emission of highly energetic charged particles emitted from the Pd/D electrode when this system is placed in either an external electrostatic or magnetostatic field. The density of tracks registered by a CR-39 detector was found to be of a magnitude that provides undisputable evidence of their nuclear origin. The experiments were reproducible. A model based upon electron capture is proposed to explain the reaction products observed in the Pd/D-D2O system.

  14. Microscopic calculations of the characteristics of radiative nuclear reactions for double-magic nuclei

    CERN Document Server

    Achakovskiy, Oleg; Tselyaev, Victor; Shitov, Mikhail

    2015-01-01

    The neutron capture cross sections and average radiative widths of neutron resonances for two double-magic nuclei 132Sn and 208Pb have been calculated using the microscopic photon strength functions, which were obtained within the microscopic self-consistent version of the extended theory of finite Fermi systems in the time blocking approximation. For the first time, the microscopic PSFs have been obtained within the fully self-consistent approach with exact accounting for the single particle continuum (for 208Pb). The approach includes phonon coupling effects in addition to the standard RPA approach. The known Skyrme force has been used. The calculations of nuclear reaction characteristics have been performed with the EMPIRE 3.1 nuclear reaction code. Here, three nuclear level density (NLD) models have been used: the so-called phenomenological GSM, the EMPIRE specific (or Enhanced GSM) and the microscopical combinatorial HFB NLD models. For both considered characteristics we found a significant disagreement ...

  15. Applying some methods to process the data coming from the nuclear reactions

    International Nuclear Information System (INIS)

    Full text : The methods of a posterior increasing the resolution of the spectral lines are offered to process the data coming from the nuclear reactions. The methods have applied to process the data coming from the nuclear reactions at high energies. They give possibilities to get more detail information on a structure of the spectra of particles emitted in the nuclear reactions. The nuclear reactions are main source of the information on the structure and physics of the atomic nuclei. Usually the spectrums of the fragments of the reactions are complex ones. Apparently it is not simple to extract the necessary for investigation information. In the talk we discuss the methods of a posterior increasing the resolution of the spectral lines. The methods could be useful to process the complex data coming from the nuclear reactions. We consider the Fourier transformation method and maximum entropy one. The complex structures were identified by the method. One can see that at lest two selected points are indicated by the method. Recent we presented a talk where we shown that the results of the analyzing the structure of the pseudorapidity spectra of charged relativistic particles with ≥ 0.7 measured in Au+Em and Pb+Em at AGS and SPS energies using the Fourier transformation method and maximum entropy one. The dependences of these spectra on the number of fast target protons were studied. These distribution shown visually some plateau and shoulder that was at least three selected points on the distributions. The plateaus become wider in PbEm reactions. The existing of plateau is necessary for the parton models. The maximum entropy method could confirm the existing of the plateau and the shoulder on the distributions. The figure shows the results of applying the maximum entropy method. One can see that the method indicates several clean selected points. Some of them same with observed visually ones. We would like to note that the Fourier transformation method could not

  16. Charged particle assisted nuclear reactions in solid state environment: renaissance of low energy nuclear physics

    CERN Document Server

    Kálmán, Péter

    2015-01-01

    The features of electron assisted neutron exchange processes in crystalline solids are survayed. It is stated that, contrary to expectations, the cross section of these processes may reach an observable magnitude even in the very low energy case because of the extremely huge increment caused by the Coulomb factor of the electron assisted processes and by the effect of the crystal-lattice. The features of electron assisted heavy charged particle exchange processes, electron assisted nuclear capure processes and heavy charged particle assisted nuclear processes are also overviewed. Experimental observations, which may be related to our theoretical findings, are dealt with. The anomalous screening phenomenon is related to electron assisted neutron and proton exchange processes in crystalline solids. A possible explanation of observations by Fleischmann and Pons is presented. The possibility of the phenomenon of nuclear transmutation is qualitatively explained with the aid of usual and charged particle assisted r...

  17. Neutron activation analysis: nuclear interference from iron in manganese

    International Nuclear Information System (INIS)

    In the present work, the contribution of iron was verified in the analysis of manganese through the reaction of interference by fast neutron. The irradiation of the samples was accomplished in the channel IC-40 of the rotary rack of the TRIGA MARK I IPR-R1 research reactor, located at Nuclear Technology Development Centre/Brazilian Commission for Nuclear Energy, CDTN/CNEN. In this irradiation device, the average thermal neutron flux is 6.69 x 1011 neutron cm-2 s-1 and fast neutron flux is 7.37 x 1010 neutron cm-2 s-1. Manganese was determined through 56Mn induced by thermal neutron flux according to the reaction 55Mn(n, γ)56Mn. In the analysis of manganese, the contribution of iron was investigated according to the reaction of interference 56Fe(n, p)56Mn produced by the fast neutron. It was verified that the contribution of 1 g of iron is 20 μg of manganese. (author)

  18. Nuclear charge and neutron radii and nuclear matter: trend analysis

    CERN Document Server

    Reinhard, P -G

    2016-01-01

    Radii of charge and neutron distributions are fundamental nuclear properties. They depend on both nuclear interaction parameters related to the equation of state of infinite nuclear matter and on quantal shell effects, which are strongly impacted by the presence of nuclear surface. In this work, by studying the dependence of charge and neutron radii, and neutron skin, on nuclear matter parameters, we assess different mechanisms that drive nuclear sizes. We apply nuclear density functional theory using a family of Skyrme functionals obtained by means of different optimization protocols targeting specific nuclear properties. By performing the Monte-Carlo sampling of reasonable functionals around the optimal parametrization, we study correlations between nuclear matter paramaters and observables characterizing charge and neutron distributions. We demonstrate the existence of the strong converse relation between the nuclear charge radii and the saturation density of symmetric nuclear matter and also between the n...

  19. Investigating resonances above and below the threshold in nuclear reactions of astrophysical interest and beyond

    Energy Technology Data Exchange (ETDEWEB)

    La Cognata, M., E-mail: lacognata@lns.infn.it [Laboratori Nazionali del Sud - INFN, Catania (Italy); Kiss, G. G. [ATOMKI, Debrecen (Hungary); Mukhamedzhanov, A. M. [Cyclotron Institute, Texas A& M University, College Station, Texas (United States); Spitaleri, C. [Laboratori Nazionali del Sud - INFN, Catania (Italy); Department of Physics and Astronomy, University of Catania, Catania (Italy); Trippella, O. [Sezione di Perugia - INFN, Perugia (Italy)

    2015-10-15

    Resonances in nuclear cross sections dramatically change their trends. Therefore, the presence of unexpected resonances might lead to unpredicted consequences on astrophysics and nuclear physics. In nuclear physics, resonances allow one to study states in the intermediate compound systems, to evaluate their cluster structure, for instance, especially in the energy regions approaching particle decay thresholds. In astrophysics, resonances might lead to changes in the nucleosynthesis flow, determining different isotopic compositions of the nuclear burning ashes. For these reasons, the Trojan Horse method has been modified to investigate resonant reactions. Thanks to this novel approach, for the first time normalization to direct data might be avoided. Moreover, in the case of sub threshold resonances, the Trojan Horse method modified to investigate resonances allows one to deduce the asymptotic normalization coefficient, showing the close connection between the two indirect approaches.

  20. Investigating resonances above and below the threshold in nuclear reactions of astrophysical interest and beyond

    Science.gov (United States)

    La Cognata, M.; Kiss, G. G.; Mukhamedzhanov, A. M.; Spitaleri, C.; Trippella, O.

    2015-10-01

    Resonances in nuclear cross sections dramatically change their trends. Therefore, the presence of unexpected resonances might lead to unpredicted consequences on astrophysics and nuclear physics. In nuclear physics, resonances allow one to study states in the intermediate compound systems, to evaluate their cluster structure, for instance, especially in the energy regions approaching particle decay thresholds. In astrophysics, resonances might lead to changes in the nucleosynthesis flow, determining different isotopic compositions of the nuclear burning ashes. For these reasons, the Trojan Horse method has been modified to investigate resonant reactions. Thanks to this novel approach, for the first time normalization to direct data might be avoided. Moreover, in the case of sub threshold resonances, the Trojan Horse method modified to investigate resonances allows one to deduce the asymptotic normalization coefficient, showing the close connection between the two indirect approaches.

  1. Analysis of nuclear power plant component failures

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    Items are shown that have caused 90% of the nuclear unit outages and/or deratings between 1971 and 1980 and the magnitude of the problem indicated by an estimate of power replacement cost when the units are out of service or derated. The funding EPRI has provided on these specific items for R and D and technology transfer in the past and the funding planned in the future (1982 to 1986) are shown. EPRI's R and D may help the utilities on only a small part of their nuclear unit outage problems. For example, refueling is the major cause for nuclear unit outages or deratings and the steam turbine is the second major cause for nuclear unit outages; however, these two items have been ranked fairly low on the EPRI priority list for R and D funding. Other items such as nuclear safety (NRC requirements), reactor general, reactor and safety valves and piping, and reactor fuel appear to be receiving more priority than is necessary as determined by analysis of nuclear unit outage causes.

  2. Informatics for analysis of nuclear experiments: TOUTATIX

    International Nuclear Information System (INIS)

    For several years in connection with the migration towards UNIX system, software tools have been developed in the laboratory. They allow the nuclear physicist community to achieve the complete analysis of experimental data. They comply with the requirements imposed by the development of multi-detectors. A special attention has been devoted to ergonomic aspects and configuration possibilities. (authors)

  3. Principal component analysis within nuclear structure

    CERN Document Server

    Al-Sayed, A

    2015-01-01

    The principal component analysis (PCA) of different parameters affecting collectivity of nuclei predicted to be candidate of the interacting boson model dynamical symmetries are performed. The results show that, the use of PCA within nuclear structure can give us a simple way to identify collectivity together with the parameters simultaneously affecting it.

  4. Calculation of photo-nuclear reaction cross sections for 16O

    Directory of Open Access Journals (Sweden)

    Arasoglu Ali

    2015-01-01

    Full Text Available Because of the high thermal expansion coefficient of uranium, the fuel used in nuclear power plants is usually in the form of UO2 which has ceramic structure and small thermal expansion coefficient. UO2 include one uranium atom and two oxygen atoms. After fission progress, total energy values of emitted gamma are about 14 MeV. This gamma energy may cause transmutation of 16O isotopes. Transmutation of 16O isotopes changes physical properties of nuclear fuel. Due to above explanations, it is very important to calculate photo-nuclear reaction cross sections of 16O. In this study; for (γ,p, (γ,np, (γ,n and (γ,2n reactions of 16O, photo-nuclear reaction cross-sections were calculated using different models for pre-equilibrium and equilibrium effects. Taking incident gamma energy values up to 40 MeV, Hybrid and Cascade Exciton Models were used for pre-equilibrium calculations and Weisskopf-Ewing (Equilibrium Model was used for equilibrium model calculations. Calculation results were compared with experimental and theoretical data. While experimental results were obtained from EXFOR, TENDL-2013, JENDL/PD-2004 and ENDF/B VII.1 data base were used to get theoretical results.

  5. Molecular forensic science analysis of nuclear materials

    Science.gov (United States)

    Reilly, Dallas David

    Concerns over the proliferation and instances of nuclear material in the environment have increased interest in the expansion of nuclear forensics analysis and attribution programs. A new related field, molecular forensic science (MFS) has helped meet this expansion by applying common scientific analyses to nuclear forensics scenarios. In this work, MFS was applied to three scenarios related to nuclear forensics analysis. In the first, uranium dioxide was synthesized and aged at four sets of static environmental conditions and studied for changes in chemical speciation. The second highlighted the importance of bulk versus particle characterizations by analyzing a heterogeneous industrially prepared sample with similar techniques. In the third, mixed uranium/plutonium hot particles were collected from the McGuire Air Force Base BOMARC Site and analyzed for chemical speciation and elemental surface composition. This work has identified new signatures and has indicated unexpected chemical behavior under various conditions. These findings have lead to an expansion of basic actinide understanding, proof of MFS as a tool for nuclear forensic science, and new areas for expansion in these fields.

  6. On the nuclear $(n;t)-$reaction in the three-electron ${}^{6}$Li atom

    CERN Document Server

    Frolov, Alexei M

    2012-01-01

    The nuclear $(n;t)-$reaction of the three-electron ${}^{6}$Li atom with thermal/slow neutrons is considered. An effective method has been developed for determining the probabilities of formation of various atoms and ions in different bound states. We discuss a number of fundamental questions directly related to numerical computations of the final state atomic probabilities. A few appropriate variational expansions for atomic wave functions of the incident lithium atom and final helium atom and/or tritium negatively charged ion are discussed. It appears that the final ${}^4$He atom arising during the nuclear $(n,{}^{6}$Li; ${}^4$He$,t)$-reaction in the three-electron Li atom can also be created in its triplet states. The formation of the quasi-stable three-electron $e^{-}_3$ during the nuclear $(n; t)-$reaction at the Li atom is briefly discussed. Bremsstrahlung emitted by atomic electrons accelerated by the rapidly moving fragments from this reaction is analyzed. The frequency spectrum of the emitted radiatio...

  7. Dependence of X-Ray Burst Models on Nuclear Reaction Rates

    CERN Document Server

    Cyburt, R H; Heger, A; Johnson, E; Keek, L; Meisel, Z; Schatz, H; Smith, K

    2016-01-01

    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,$\\gamma$), ($\\alpha$,$\\gamma$), and ($\\alpha$,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 highest impact reaction rate changes were then repeated in the 1D multi-zone model. We find a number of uncertain reac...

  8. Nuclear spectrum analysis by using microcomputer

    International Nuclear Information System (INIS)

    A method is presented for analysis of nuclear spectra by using microcomputer. A nonlinear least square fit of a mathematical model with observed spectrum is performed with variable metric method. The linear search procedure of the variable metric method has been modified so that the algorithm needs less program space and computational time both of which are important for microcomputer implementation. This widely used peak analysis method can now be made available in microcomputer based multichannel analysers. (author)

  9. Report on the consultants' meeting on technical aspects of the co-operation of nuclear reaction data centers

    International Nuclear Information System (INIS)

    The IAEA Nuclear Data Section convenes in annual intervals coordination meetings of the Network of the Nuclear Reaction Data Center. The present meeting dealt with technical matters of the nuclear data compilation and exchange by means of the jointly operated computerized systems CINDA, EXFOR, ENDF and others. Refs, figs and tabs

  10. Experimental studies of keV energy neutron-induced reactions relevant to astrophysics and nuclear physics

    Energy Technology Data Exchange (ETDEWEB)

    Shima, T.; Kii, T.; Kikuchi, T.; Okazaki, F.; Kobayashi, T.; Baba, T.; Nagai, Y. [Tokyo Inst. of Tech. (Japan). Faculty of Science; Igashira, M.

    1997-03-01

    Nuclear reactions induced by keV energy neutrons provide a plenty of informations for studies of both astrophysics and nuclear physics. In this paper we will show our experimental studies of neutron- induced reactions of light nuclei in the keV energy region by means of a pulsed keV neutron beam and high-sensitivity detectors. Also we will discuss astrophysical and nuclear-physical consequences by using the obtained results. (author)

  11. EXFOR basics: A short guide to the nuclear reaction data exchange format

    International Nuclear Information System (INIS)

    This manual is intended as a guide to users of nuclear reaction data compiled in the EXFOR format, and is not intended as a complete guide to the EXFOR System. EXFOR is the exchange format designed to allow transmission of nuclear data between the Nuclear Reaction Data Centers. In addition to storing the data and its' bibliographic information, experimental information, including source of uncertainties, is also compiled. The status and history of the data set is also included, e.g., the source of the data, any updates which have been made, and correlations to other data sets. EXFOR is designed for flexibility in order to meet the diverse needs of the nuclear data compilation centers. This format should not be confused with a center-to-user format. Although users may obtain data from the centers in the EXFOR format, other center-to-user formats have been developed to meet the needs of the users within each center's own sphere of responsibility. The exchange format, as outlined, allows a large variety of numerical data tables with explanatory and bibliographic information to be transmitted in an easily machine-readable format (for checking and indicating possible errors) and a format that can be read by personnel (for passing judgment on and correcting any errors indicated by the machine). The data presently included in the EXFOR exchange include: a complete compilation of experimental neutron-induced reaction data, a selected compilation of charged-particle induced reaction data, a selected compilation of photon-induced reaction data

  12. EXFOR basics: A short guide to the nuclear reaction data exchange format

    Energy Technology Data Exchange (ETDEWEB)

    McLane, V.

    1996-07-01

    This manual is intended as a guide to users of nuclear reaction data compiled in the EXFOR format, and is not intended as a complete guide to the EXFOR System. EXFOR is the exchange format designed to allow transmission of nuclear data between the Nuclear Reaction Data Centers. In addition to storing the data and its` bibliographic information, experimental information, including source of uncertainties, is also compiled. The status and history of the data set is also included, e.g., the source of the data, any updates which have been made, and correlations to other data sets. EXFOR is designed for flexibility in order to meet the diverse needs of the nuclear data compilation centers. This format should not be confused with a center-to-user format. Although users may obtain data from the centers in the EXFOR format, other center-to-user formats have been developed to meet the needs of the users within each center`s own sphere of responsibility. The exchange format, as outlined, allows a large variety of numerical data tables with explanatory and bibliographic information to be transmitted in an easily machine-readable format (for checking and indicating possible errors) and a format that can be read by personnel (for passing judgment on and correcting any errors indicated by the machine). The data presently included in the EXFOR exchange include: a complete compilation of experimental neutron-induced reaction data, a selected compilation of charged-particle induced reaction data, a selected compilation of photon-induced reaction data.

  13. Reactions analysis of di-pions production

    International Nuclear Information System (INIS)

    After a discussion of ambiguities in the methods used to obtain informations on the ππ diffusion from the reaction π-p→π+π-n with unpolarized targets, a model-independent method is proposed to determine experimentally the cross section for the S-wave production in the reaction π+p→π+π-Δ++. Comparing the S-wave di-pion production in the ζ-mass region from the recent experimental results on the reactions π+p→π=π-Δ++ and π-p→π-π+n on a polarized target, it is found that the amount of S-wave production is generally consistent with the lower bound obtained from the di-pion decay moments

  14. Compound-nuclear reactions with unstable nuclei: Constraining theory through innovative experimental approaches

    Directory of Open Access Journals (Sweden)

    Escher J. E.

    2016-01-01

    Full Text Available Cross sections for compound-nuclear reactions involving unstable targets are important for many applications, but can often not be measured directly. Several indirect methods have recently been proposed to determine neutron capture cross sections for unstable isotopes. We consider three approaches that aim at constraining statistical calculations of capture cross sections with data obtained from the decay of the compound nucleus relevant to the desired reaction. Each method produces this compound nucleus in a different manner (via a light-ion reaction, a photon-induced reaction, or β-decay and requires additional ingredients to yield the sought-after cross section. We give a brief outline of the approaches and employ preliminary results from recent measurements to illustrate the methods. We discuss the main advantages and challenges of each approach.

  15. Absorption-Fluctuation Theorem for Nuclear Reactions: Brink-Axel, Incomplete Fusion and All That

    International Nuclear Information System (INIS)

    We discuss the connection between absorption, averages and fluctuations in nuclear reactions. The fluctuations in the entrance channel result in the compound-nucleus Hauser-Feshbach cross section, and the fluctuations in the intermediate channels result in modifications of multistep reaction cross sections, while the fluctuations in the final channel result in hybrid cross sections that can be used to describe incomplete fusion reactions. We discuss the latter in detail and comment on the validity of the assumptions used in the development of the Surrogate method. We also discuss the theory of multistep reactions with regards to intermediate state fluctuations and the energy dependence and non-locality of the intermediate-channel optical potentials

  16. Evolutionary implications of the new triple-alpha nuclear reaction rate for low mass stars

    CERN Document Server

    Dotter, Aaron

    2009-01-01

    Context: Ogata et al. (2009; hereafter OKK) presented a theoretical determination of the triple-alpha nuclear reaction rate. Their rate differs from the NACRE rate by many orders of magnitude at temperatures relevant for low mass stars. Aims: We explore the evolutionary implications of adopting the OKK triple-alpha reaction rate in low mass stars and compare the results with those obtained using the NACRE rate. Methods: The triple-alpha reaction rates are compared by following the evolution of stellar models at 1 and 1.5 Msol with Z=0.0002 and Z=0.02. Results: Results show that the OKK rate has severe consequences for the late stages of stellar evolution in low mass stars. Most notable is the shortening--or disappearance--of the red giant phase. Conclusions: The OKK triple-alpha reaction rate is incompatible with observations of extended red giant branches and He burning stars in old stellar systems.

  17. Compound-nuclear reactions with unstable nuclei: Constraining theory through innovative experimental approaches

    Science.gov (United States)

    Escher, J. E.; Tonchev, A. P.; Burke, J. T.; Bedrossian, P.; Casperson, R. J.; Cooper, N.; Hughes, R. O.; Humby, P.; Ilieva, R. S.; Ota, S.; Pietralla, N.; Scielzo, N. D.; Werner, V.

    2016-06-01

    Cross sections for compound-nuclear reactions involving unstable targets are important for many applications, but can often not be measured directly. Several indirect methods have recently been proposed to determine neutron capture cross sections for unstable isotopes. We consider three approaches that aim at constraining statistical calculations of capture cross sections with data obtained from the decay of the compound nucleus relevant to the desired reaction. Each method produces this compound nucleus in a different manner (via a light-ion reaction, a photon-induced reaction, or β-decay) and requires additional ingredients to yield the sought-after cross section. We give a brief outline of the approaches and employ preliminary results from recent measurements to illustrate the methods. We discuss the main advantages and challenges of each approach.

  18. Squids, supercurrents, and slope anomalies: Nuclear structure from heavy-ion transfer reactions

    International Nuclear Information System (INIS)

    Within the past five years we have developed experimental techniques to study heavy-ion transfer reactions to high spin states in deformed nuclei. These methods have been turned into a quantitative tool to assess the influence of collective excitation on single-particle and pairing structure. I discuss some of the nuclear structure questions which are being answered in these experiments: How strong is ground state pairing? How does pairing change with angular momentum? Why is two-neutron transfer much stronger than expected at large radial separation? What is the evidence for a nuclear Josephson Effect? What is the evidence for a nuclear Berry phase effect (nuclear SQUID)? Why does one-neutron transfer populate much higher spins than would be naively expected? Conversely, why does two-neutron transfer populate much lower spins than anyone expected? The answer to each of these questions involves the influence of detailed nuclear structure on transfer reactions, and represents quantitative new information about the effect of angular momentum and excitation energy on many-body systems with a finite number of particles. 8 refs., 6 figs

  19. The Legnaro National Laboratories and the SPES facility: nuclear structure and reactions today and tomorrow

    Science.gov (United States)

    de Angelis, Giacomo; Fiorentini, Gianni

    2016-11-01

    There is a very long tradition of studying nuclear structure and reactions at the Legnaro National Laboratories (LNL) of the Istituto Nazionale di Fisica Nucleare (Italian Institute of Nuclear Physics). The wide expertise acquired in building and running large germanium arrays has made the laboratories one of the most advanced research centers in γ-ray spectroscopy. The ’gamma group’ has been deeply involved in all the national and international developments of the last 20 years and is currently one of the major contributors to the AGATA project, the first (together with its American counterpart GRETINA) γ-detector array based on γ-ray tracking. This line of research is expected to be strongly boosted by the coming into operation of the SPES radioactive ion beam project, currently under construction at LNL. In this report, written on the occasion of the 40th anniversary of the Nobel prize awarded to Aage Bohr, Ben R Mottelson and Leo Rainwater and particularly focused on the physics of nuclear structure, we intend to summarize the different lines of research that have guided nuclear structure and reaction research at LNL in the last decades. The results achieved have paved the way for the present SPES facility, a new laboratories infrastructure producing and accelerating radioactive ion beams of fission fragments and other isotopes.

  20. Comparative Studies of Chemical Effects following Nuclear Reactions and Transformations on Metal Organic Phenyl Compounds

    International Nuclear Information System (INIS)

    A study of the chemical effects created by the energetic recoil atoms of nuclear reactions in solids and liquids was made on the basis of a broad comparison of the products formed by (n, γ) and (n, 2n) processes in the metalphenyl compounds of germanium, tin, lead, arsenic and antimony. In addition, the radioactive recoil products formed after the K-capture process on Ge68 - tetraphenyl are compared with the results from the (n, γ) -process on Ga-triphenyl and the (n,p) process on Ge-tetra phenyl. Finally, the studies include the β- transition on Ge77-tetraphenyl to As77. Applying different separation methods, e.g. adsorption chromatography on alumina, ion exchange and electrophoresis, the various radioactive recoil products were separated and the individual yields determined. It was found that in nuclear reactions the compounds of the mentioned metals having identical ligands formed practically the same classes of recoil products. The yield distribution however reveals characteristic alterations between the (n, γ) and (n, 2n) reaction. Only a small influence on the yields is perceptible when irradiations are performed in liquids and solutions. The large differences found for the new compounds formed by nuclear transformations are striking, not only in the kind of typical products but also in their percentage yields. Thus, several recoil products of Ge and Ga with metalorganic character were found by nuclear reactions on Ge-tetraphenyl that could not be detected at all by the K-capture process on Ge68-tetraphenyl. The β- decay on Ge77-tetraphenyl produces practically the same chemical compounds as were observed by nuclear reactions. However, a remarkable increase in the portion of the labelled parent molecules (retention) is typical for the β- transition. The results are discussed on the basis of theoretical considerations of the amount of kinetic energy transferred to the reacting molecule by the nuclear recoil and the resulting excitation. The hypothesis is

  1. Nuclear radiation analysis for TFTR

    International Nuclear Information System (INIS)

    A multi-dimensional analysis of the radiation problems was performed for TFTR using the system established at PPPL. Simple, clean geometries were first used to establish the expected reference level. Different calculational models were compared. The characteristics of streaming and activation were then studied. It is shown that the objectives set forth for the TFTR shielding design are not entirely satisfied, based on our calculation. Using the results of this study as a baseline, a review of the shielding for TFTR and its upgrade, TFM, has been initiated with the objective of a shielding design modified to satisfy both modes of operation

  2. Economic analysis of nuclear power generation

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ki Dong; Choi, Young Myung; Kim, Hwa Sup; Lee, Man Ki; Moon, Kee Hwan; Kim, Seung Su; Chae, Kyu Nam

    1996-12-01

    The major contents in this study are as follows : (1) Efforts are made to examine the role of nuclear energy considering environmental regulation. An econometric model for energy demand and supply including carbon tax imposition is established. (2) Analysis for the learning effect of nuclear power plant operation is performed. The study is focused to measure the effect of technology homogeneity on the operation performance. (3) A preliminary capital cost of the KALIMER is estimated by using cost computer program, which is developed in this study. (author). 36 refs.,46 tabs., 15 figs.

  3. Activation Analysis and Nuclear Research in Burma

    International Nuclear Information System (INIS)

    Research endeavours in the field of Nuclear Sciences in Burma appear to be concentrated in three main Institutions. These are the Chemistry and Physics Departments of the Rangoon Arts & Science University and the Union of Burma Applied Research Institute (UBARI). In view of possible forthcoming developments an expanded research programme, which is to be implemented on the basis of a five year plan, has been drawn up. Research topics included in this programme are predominantly of practical interest and aimed at a contribution by nuclear methods, in particular activation analysis, to the technological and industrial needs of the country

  4. Nuclear fragmentation reactions in extended media studied with Geant4 toolkit

    CERN Document Server

    Pshenichnov, Igor; Mishustin, Igor; Greiner, Walter

    2009-01-01

    It is well known from numerous experiments that nuclear multifragmentation is a dominating mechanism for production of intermediate-mass fragments in nucleus-nucleus collisions at energies above 100 A MeV. In this paper we investigate the validity and performance of the Fermi break-up model and the statistical multifragmentation model implemented as parts of the Geant4 toolkit. We study the impact of violent nuclear disintegration reactions on the depth-dose profiles and yields of secondary fragments for beams of light and medium-weight nuclei propagating in extended media. Implications for ion-beam cancer therapy and shielding from cosmic radiation are discussed.

  5. Effect of nuclear spin symmetry in cold and ultracold reactions: D + para/ortho-H$_2$

    OpenAIRE

    Simbotin, I.; Côté, R

    2015-01-01

    We report results for reaction and vibrational quenching of the collision D with para-H$_2$($v,j=0$) and ortho-H$_2$($v,j=1$) at cold and ultracold temperatures. We investigate the effect of nuclear spin symmetry for barrier dominated processes ($0\\le v\\le 4$) and for one barrierless case ($v=5$). We find resonant structures for energies in the range corresponding to 0.01--10 K, which depend on the nuclear spin of H$_2$, arising from contributions of specific partial waves. We discuss the imp...

  6. Effect of nuclear spin symmetry in cold and ultracold reactions: D + para/ortho-H$_2$

    CERN Document Server

    Simbotin, I

    2015-01-01

    We report results for reaction and vibrational quenching of the collision D with para-H$_2$($v,j=0$) and ortho-H$_2$($v,j=1$) at cold and ultracold temperatures. We investigate the effect of nuclear spin symmetry for barrier dominated processes ($0\\le v\\le 4$) and for one barrierless case ($v=5$). We find resonant structures for energies in the range corresponding to 0.01--10 K, which depend on the nuclear spin of H$_2$, arising from contributions of specific partial waves. We discuss the implications on the results in this benchmark system for ultracold chemistry.

  7. Sunflower oil ozonation. Following of the reaction by proton Nuclear Magnetic Resonance

    International Nuclear Information System (INIS)

    Previous studies have demonstrated that the technique of Proton Nuclear Magnetic Resonance can be used for the pursuit of the reaction between the ozone and the unsaturated fatty acids. It's carried out the sunflower oil ozonization to different applied dose of ozone and the index of peroxides and the concentration of aldehydes are determined. The main reaction products were identified by Proton Nuclear Magnetic Resonance Spectroscopy (NMR 1 H). The intensities of the signs were used to follow the advance of the reaction between the ozone and the sunflower oil. It is was carried out until obtaining an index of peroxides of 1 202 mmol-equiv/kg. The intensities of the signs of the olefinic protons diminish with a gradual increment in the dose of applied ozone, but without ending up disappearing completely. The ozonides of Criegee obtained to applied dose of ozone of 107,1 mg/g were approximately bigger 7,4 times that those obtained at the beginning from the reaction to applied dose of ozone of 15,3 mg/g. The aldehydes protons were observed as a sign of weak intensity in all the spectra. The signs belonging to the olenifics protons of the hydroperoxides in d = 5,55 ppm increases with the increment of the applied dose of ozone. You concludes that to higher applied dose of ozone, haggler is the advance of the ozonization reaction, what belongs together with a bigger formation of oxygenated compounds

  8. Supporting the Josephson Interpretation of Low Energy Nuclear Reactions and Stabilization of Nuclear Waste

    OpenAIRE

    Osman, F; Hora, H.; Li, X Z; Miley, G. H.; J. C. Kelly

    2005-01-01

    Brian Josephson appealed at the meeting of the Nobel Laureates July 2004 against the ignorance of physicist to the phenomenon of cold fusion. Though there are good reasons against many publications on this topic but not for all what was reported. It seems to be indicated to summarize the following serious, reproducible and confirmed observations on the reactions of protons or deuterons incorporated in host metals such as palladium, nickel and other metals. We underline the confusing discovery...

  9. Error analysis of nuclear forces and effective interactions

    CERN Document Server

    Perez, R Navarro; Arriola, E Ruiz

    2014-01-01

    The Nucleon-Nucleon interaction is the starting point for ab initio Nuclear Structure and Nuclear reactions calculations. Those are effectively carried out via effective interactions fitting scattering data up to a maximal center of mass momentum. However, NN interactions are subjected to statistical and systematic uncertainties which are expected to propagate and have some impact on the predictive power and accuracy of theoretical calculations, regardless on the numerical accuracy of the method used to solve the many body problem. We stress the necessary conditions required for a correct and self-consistent statistical interpretation of the discrepancies between theory and experiment which enable a subsequent statistical error propagation and correlation analysis. We comprehensively discuss an stringent and recently proposed tail-sensitive normality test and provide a simple recipe to implement it. As an application, we analyze the deduced uncertainties and correlations of effective interactions in terms of ...

  10. Investigation of Proton Emission Spectra of Some Nuclear Reactor Materials for (p,xp) Reactions

    OpenAIRE

    Aynur TATAR; Tel, Eyyup

    2010-01-01

    Proton-emission spectra produced by (p,xp) reactions for some nuclear reactor and particle accelerator material 56Fe and 60Ni target nuclei have been investigated by a proton beam up to 50 MeV. In these calculations, the pre-equilibrium effects have been investigated. The calculated results are compared with the experimental data taken from literature. Key words: (p,xp) reactions, Weisskopf-Ewing model, Full- Exciton model Bazı Nükleer Reaktör Materyallerinin (p,xp) Reaksiyonlarının ...

  11. Quantitative Analysis in Nuclear Medicine Imaging

    CERN Document Server

    2006-01-01

    This book provides a review of image analysis techniques as they are applied in the field of diagnostic and therapeutic nuclear medicine. Driven in part by the remarkable increase in computing power and its ready and inexpensive availability, this is a relatively new yet rapidly expanding field. Likewise, although the use of radionuclides for diagnosis and therapy has origins dating back almost to the discovery of natural radioactivity itself, radionuclide therapy and, in particular, targeted radionuclide therapy has only recently emerged as a promising approach for therapy of cancer and, to a lesser extent, other diseases. As effort has, therefore, been made to place the reviews provided in this book in a broader context. The effort to do this is reflected by the inclusion of introductory chapters that address basic principles of nuclear medicine imaging, followed by overview of issues that are closely related to quantitative nuclear imaging and its potential role in diagnostic and therapeutic applications. ...

  12. Bimodal Nuclear Thermal Rocket Analysis Developments

    Science.gov (United States)

    Belair, Michael; Lavelle, Thomas; Saimento, Charles; Juhasz, Albert; Stewart, Mark

    2014-01-01

    Nuclear thermal propulsion has long been considered an enabling technology for human missions to Mars and beyond. One concept of operations for these missions utilizes the nuclear reactor to generate electrical power during coast phases, known as bimodal operation. This presentation focuses on the systems modeling and analysis efforts for a NERVA derived concept. The NERVA bimodal operation derives the thermal energy from the core tie tube elements. Recent analysis has shown potential temperature distributions in the tie tube elements that may limit the thermodynamic efficiency of the closed Brayton cycle used to generate electricity with the current design. The results of this analysis are discussed as well as the potential implications to a bimodal NERVA type reactor.

  13. Nuclear Level Densities for Modeling Nuclear Reactions: An Efficient Approach Using Statistical Spectroscopy

    International Nuclear Information System (INIS)

    The general goal of the project is to develop and implement computer codes and input files to compute nuclear densities of state. Such densities are important input into calculations of statistical neutron capture, and are difficult to access experimentally. In particular, we will focus on calculating densities for nuclides in the mass range A ∼ 50-100. We use statistical spectroscopy, a moments method based upon a microscopic framework, the interacting shell model. Second year goals and milestones: Develop two or three competing interactions (based upon surface-delta, Gogny, and NN-scattering) suitable for application to nuclei up to A = 100. Begin calculations for nuclides with A = 50-70

  14. Reaction mechanisms in transport theories: a test of the nuclear effective interaction

    CERN Document Server

    Colonna, M; Di Toro, M; Frecus, B; Zhang, Y X

    2012-01-01

    We review recent results concerning collective excitations in neutron-rich systems and reactions between charge asymmetric systems at Fermi energies. Solving numerically self-consistent transport equations for neutrons and protons with specific initial conditions, we explore the structure of the different dipole vibrations in the $^{132}Sn$ system and investigate their dependence on the symmetry energy. We evidence the existence of a distinctive collective mode, that can be associated with the Pygmy Dipole Resonance, with an energy well below the standard Giant Dipole Resonance and isoscalar-like character, i.e. very weakly dependent on the isovector part of the nuclear effective interaction. At variance, the corresponding strength is rather sensitive to the behavior of the symmetry energy below saturation, which rules the number of excess neutrons in the nuclear surface. In reactions between charge asymmetric systems at Fermi energies, we investigate the interplay between dissipation mechanisms and isospin e...

  15. Isospin aspects in nuclear reactions involving Ca beams at 25 MeV/nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Lombardo, I., E-mail: ilombardo@lns.infn.it; Agodi, C.; Alba, R.; Amorini, F.; Anzalone, A. [INFN Laboratori Nazionali del Sud (Italy); Auditore, L. [Universita di Messina, and INFN-Gr. Coll. Messina, Dipartimento di Fisica (Italy); Berceanu, I. [Institute for Physics and Nuclear Engineering (Romania); Cardella, G. [INFN, Sezione di Catania (Italy); Cavallaro, S. [INFN Laboratori Nazionali del Sud (Italy); Chatterjee, M. B. [Saha Institute of Nuclear Physics (India); Filippo, E. De [INFN, Sezione di Catania (Italy); Di Pietro, A.; Figuera, P. [INFN Laboratori Nazionali del Sud (Italy); Giuliani, G.; Geraci, E.; Grassi, L. [Dipartimento di Fisica e Astronomia Universita di Catania (Italy); Grzeszczuk, A. [University of Silesia, Institute of Physics (Poland); Han, J. [INFN Laboratori Nazionali del Sud (Italy); La Guidara, E. [INFN, Sezione di Catania (Italy); Lanzalone, G. [INFN Laboratori Nazionali del Sud (Italy); and others

    2011-11-15

    Isospin dependence of dynamical and thermodynamical properties observed in reactions {sup 40}Ca+ {sup 40,48}Ca and {sup 40}Ca + {sup 46}Ti at 25 MeV/nucleon has been studied. We used the CHIMERA multi-detector array. Strong isospin effects are seen in the isotopic distributions of light nuclei and in the competition between different reaction mechanisms in semi-central collisions. We will show also preliminary results obtained in nuclear collision {sup 48}Ca + {sup 48}Ca at 25MeV/nucleon, having very high N/Z value in the entrance channel (N/Z = 1.4). The enhancement of evaporation residue production confirms the strong role played by the N/Z degree of freedom in nuclear dynamics.

  16. Spallation reaction and the probe of nuclear dissipation with excitation energy at scission

    International Nuclear Information System (INIS)

    We study in the framework of the Langevin model the influence of initial excitation energy (E*) of Hg compound nuclei (CNs) on the sensitivity of the excitation energy at scission (Esc*) to the nuclear friction strength (β). It is shown that the sensitivity is enhanced substantially with increasing E*. Moreover, we find that the significant sensitivity of Esc* to β at high E* is little affected by a marked difference in the neutron-to-proton ratio of a CN and in its size and fissility. Our findings suggest that, on the experimental side, a measurement of Esc* in energetic proton-induced spallation reactions can provide not only a sensitive but also a robust probe of nuclear dissipation in fission of highly excited nuclei. Further development of a suitable approach to spallation reaction is discussed. (authors)

  17. The Trojan Horse method for nuclear astrophysics: Recent results on resonance reactions

    Science.gov (United States)

    La Cognata, M.; Spitaleri, C.; Cherubini, S.; Gulino, M.; Lamia, L.; Pizzone, R. G.; Romano, S.; Tumino, A.

    2014-05-01

    Nuclear astrophysics aims to measure nuclear-reaction cross sections of astrophysical interest to be included into models to study stellar evolution and nucleosynthesis. Low energies, Trojan Horse Method have been devised yielding new cutting-edge results. In particular, I will focus on the application of this indirect method to resonance reactions. Resonances might dramatically enhance the astrophysical S(E)-factor so, when they occur right at astrophysical energies, their measurement is crucial to pin down the astrophysical scenario. Unknown or unpredicted resonances might introduce large systematic errors in nucleosynthesis models. These considerations apply to low-energy resonances and to sub-threshold resonances as well, as they may produce sizable modifications of the S-factor due to, for instance, destructive interference with another resonance.

  18. Report on the IAEA technical meeting of the International Network of Nuclear Reaction Data Centres

    International Nuclear Information System (INIS)

    An IAEA Technical Meeting of the International Network of Nuclear Reaction Data Centres was held at IAEA Headquarters, Vienna, Austria, from 8 to 10 October 2007. The meeting was attended by 19 participants from 11 cooperating data centres of six Member States and two international organizations. A summary of the meeting is given in this report, along with the conclusions, actions, and status reports of the participating data centres. (author)

  19. Report on the IAEA advisory group meeting on network of nuclear reaction data centres

    International Nuclear Information System (INIS)

    This report summarizes the IAEA Advisory Group Meeting (AGM) on Network of Nuclear Reaction Data Centres, hold at the Institute of Physics and Power Engineering, Obninsk, Russia, 15 to 19 May 2000. The meeting was attended by 28 participants from 13 co-operating data centres from seven Member States and two International Organizations. The report contains a meeting summary, the conclusions and actions, progress and status reports of the participating data centres and working papers considered at the meeting. (author)

  20. Summary Report of the Technical Meeting on International Network of Nuclear Reaction Data Centres

    International Nuclear Information System (INIS)

    This report summarizes the IAEA Technical Meeting on the International Network of Nuclear Reaction Data Centres, held at the IAEA Headquarters in Vienna, Austria from 23 to 25 April 2013. The meeting was attended by 24 participants representing 13 cooperative centres from 8 Member States and 2 International Organisations. A summary of the meeting is given in this report along with the conclusions and actions. (author)

  1. Report on the IAEA technical meeting on network of nuclear reaction data centres

    International Nuclear Information System (INIS)

    An IAEA Technical Meeting on the Network of Nuclear Reaction Data Centres (biennial Data Centre Heads Meeting) was held at IAEA Headquarters, Vienna, Austria, from 25 to 28 September 2006. The meeting was attended by 19 participants from 10 cooperating data centres of six Member States and two international organizations. A summary of the meeting is given in this report, along with the conclusions, actions, and status reports of the participating data centres. (author)

  2. Report on the IAEA technical meeting on the network of nuclear reaction data centres

    International Nuclear Information System (INIS)

    Results of the IAEA Technical meeting on the Network of Nuclear Reaction Data Centres held at the IAEA Headquarters, Vienna, Austria, 12 to 14 October 2005, are summarized in this report. The meeting was attended by 16 participants from 11 co-operating data centres of six Member States and two International Organizations. The report contains a summary of the meeting, the conclusions and actions, and status reports of the participating data centres. (author)

  3. Nuclear analysis methods in monitoring occupational health

    International Nuclear Information System (INIS)

    With the increasing industrialisation of the world has come an increase in exposure to hazardous chemicals. Their effect on the body depends upon the concentration of the element in the work environment; its chemical form; the possible different routes of intake; and the individual's biological response to the chemical. Nuclear techniques of analysis such as neutron activation analysis (NAA) and proton induced X-ray emission analysis (PIXE), have played an important role in understanding the effects hazardous chemicals can have on occupationally exposed workers. In this review, examples of their application, mainly in monitoring exposure to heavy metals is discussed

  4. Pion-nucleus inelastic scattering: Reaction contributions and nuclear spin determinations

    International Nuclear Information System (INIS)

    Formulas for pion-nucleus inelastic scattering are presented in a form that may suggest experiments to isolate various contributions to the reaction, including S-wave, P-wave spin and nonspin flip, and effects of nucleon Fermi motion. Adopting a form of the distorted wave impulse appoximation, we obtain an expression for inelastic cross sections that clearly separate the pion laboratory energy (E), three-momentum transfer (q), and scattering angle (theta) dependences. The result is similar to the separation of longitudinal and transverse form factors in inelastic electron scattering. By varying the energy of the incident pion, but working at fixed q, one can determine whether a given nuclear excitation has natural or unnatural parity. By working at fixed theta, and varying E and thus q, one can isolate different reaction contributions: spin, scalar, and ''convection current.'' We also discuss the potential usefulness of studying the energy dependence of angle-integrated differential cross sections at fixed energy loss. The predictions of our formulas are in good agreement with recent data on natural and unnatural parity excitations in 12C(π,π')12C*. Thus, this approach may be useful in analyzing future data in which the final nuclear spin is uncertain. Future experiments with selective q, E, and theta variations to separate nuclear structure from reaction-mechanism uncertainties are suggested

  5. Experimental and phenomenological comparison between Piezonuclear reactions and Condensed Matter Nuclear Science phenomenology

    CERN Document Server

    Cardone, F; Petrucci, A

    2011-01-01

    The purpose of this paper is to place side by side the experimental results of Piezonu- clear reactions, which have been recently unveiled, and those collected during the last twenty years of experiments on low energy nuclear reactions (LENR). We will briefy re- port the results of our campaign of piezonuclear reactions experiments where ultrasounds and cavitation were applied to solutions of stable elements. These outcomes will be shown to be compatible with the results and evidences obtained from low energy nuclear reac- tion experiments. Some theoretical concepts and ideas, on which our experiments are grounded, will be sketched and it will be shown that, in order to trigger our measured effects, it exists an energy threshold, that has to be overcome, and a maximum inter- val of time for this energy to be released to the nuclear system. Eventually, a research hypothesis will be put forward about the chance to raise the level of analogy from the mere comparison of results up to the phenomenological level. H...

  6. Charged particle-induced nuclear fission reactions – Progress and prospects

    Indian Academy of Sciences (India)

    S Kailas; K Mahata

    2014-12-01

    The nuclear fission phenomenon continues to be an enigma, even after nearly 75 years of its discovery. Considerable progress has been made towards understanding the fission process. Both light projectiles and heavy ions have been employed to investigate nuclear fission. An extensive database of the properties of fissionable nuclei has been generated. The theoretical developments to describe the fission phenomenon have kept pace with the progress in the corresponding experimental measurements. As the fission process initiated by the neutrons has been well documented, the present article will be restricted to charged particle-induced fission reactions. The progress made in recent years and the prospects in the area of nuclear fission research will be the focus of this review.

  7. Nuclear model calculations on the production of {sup 119}Sb via various nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Mahdi, E-mail: msadeghi@nrcam.org [Agricultural, Medical and Industrial Research School, Nuclear Science and Technology Research Institute, P.O. Box 31485/498, Karaj (Iran, Islamic Republic of); Enferadi, Milad [Research and Science Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2011-04-15

    Only very few radionuclides exist that decay exclusively by EC-mode without accompanying radiation, {sup 119}Sb is one of them. Auger emitter {sup 119}Sb (T{sub 1/2} = 38.9 h, I{sub EC} = 100%) is a potent nuclide for targeted radionuclide therapy based on theoretical dosimetry calculations at a subcellular scale. Auger electron emitting radionuclides in cancer therapy offer the opportunity to deliver a high radiation dose to the tumor cells with high radiotoxicity while minimizing toxicity to normal tissue. {sup 119}Sb excitation function via {sup 119}Sn(p,n){sup 119}Sb, {sup 120}Sn(p,2n){sup 119}Sb, {sup 121}Sb(p,3n){sup 119}Te {yields} {sup 119}Sb, {sup 122}Sn(p,4n){sup 119}Sb, {sup 119}Sn(d,2n){sup 119}Sb and {sup 117}Sn({alpha},2n){sup 119}Te {yields} {sup 119}Sb reactions were calculated by ALICE/91, ALICE/ASH (GDH Model and Hybrid Model) and TALYS-1.0 (equilibrium and pre-equilibrium) codes. Requisite thicknesses of targets were obtained by SRIM code for each reaction.

  8. Nuclear model calculations on the production of 119Sb via various nuclear reactions

    International Nuclear Information System (INIS)

    Only very few radionuclides exist that decay exclusively by EC-mode without accompanying radiation, 119Sb is one of them. Auger emitter 119Sb (T1/2 = 38.9 h, IEC = 100%) is a potent nuclide for targeted radionuclide therapy based on theoretical dosimetry calculations at a subcellular scale. Auger electron emitting radionuclides in cancer therapy offer the opportunity to deliver a high radiation dose to the tumor cells with high radiotoxicity while minimizing toxicity to normal tissue. 119Sb excitation function via 119Sn(p,n)119Sb, 120Sn(p,2n)119Sb, 121Sb(p,3n)119Te → 119Sb, 122Sn(p,4n)119Sb, 119Sn(d,2n)119Sb and 117Sn(α,2n)119Te → 119Sb reactions were calculated by ALICE/91, ALICE/ASH (GDH Model and Hybrid Model) and TALYS-1.0 (equilibrium and pre-equilibrium) codes. Requisite thicknesses of targets were obtained by SRIM code for each reaction.

  9. Advancing the Theory of Nuclear Reactions with Rare Isotopes: From the Laboratory to the Cosmos

    Energy Technology Data Exchange (ETDEWEB)

    Elster, Charlotte [Ohio Univ., Athens, OH (United States)

    2015-06-01

    The mission of the TORUS Topical Collaboration is to develop new methods that will advance nuclear reaction theory for unstable isotopes by using three-body techniques to improve direct-reaction calculations, and, by using a new partial-fusion theory, to integrate descriptions of direct and compound-nucleus reactions. Ohio University concentrates its efforts on the first part of the mission. Since direct measurements are often not feasible, indirect methods, e.g. (d,p) reactions, should be used. Those (d,p) reactions may be viewed as three-body reactions and described with Faddeev techniques. Faddeev equations in momentum space have a long tradition of utilizing separable interactions in order to arrive at sets of coupled integral equations in one variable. While there exist several separable representations for the nucleon-nucleon interaction, the optical potential between a neutron (proton) and a nucleus is not readily available in separable form. For this reason we first embarked in introducing a separable representation for complex phenomenological optical potentials of Woods-Saxon type.

  10. Information Services at the Nuclear Safety Analysis Center.

    Science.gov (United States)

    Simard, Ronald

    This paper describes the operations of the Nuclear Safety Analysis Center. Established soon after an accident at the Three Mile Island nuclear power plant near Harrisburg, Pennsylvania, its efforts were initially directed towards a detailed analysis of the accident. Continuing functions include: (1) the analysis of generic nuclear safety issues,…

  11. Nuclear Structure and Reaction Properties of Ne, Mg and Si Isotopes with RMF Densities

    CERN Document Server

    Panda, R N; Patra, S K

    2013-01-01

    We have studied nuclear structure and reaction properties of Ne, Mg and Si isotopes, using relativistic mean field densities, in the frame work of Glauber model. Total reaction cross section $\\sigma_R$ for Ne isotopes on 12C target have been calculated at incident energy 240 MeV. The results are compared with the experimental data and with the recent theoretical study [W. Horiuchi et al., Phys. Rev. C, 86, 024614 (2012)]. Study of $\\sigma_R$ using deformed densities have shown a good agreement with the data. We have also predicted total reaction cross section $\\sigma_R$ for Ne, Mg and Si isotopes as projectiles and 12C as target at different incident energies.

  12. γ-Particle coincidence technique for the study of nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Zagatto, V.A.B., E-mail: vinicius.zagatto@gmail.com [Instituto de Física da Universidade de São Paulo (Brazil); Oliveira, J.R.B.; Allegro, P.R.P.; Chamon, L.C.; Cybulska, E.W.; Medina, N.H.; Ribas, R.V.; Seale, W.A.; Silva, C.P.; Gasques, L.R. [Instituto de Física da Universidade de São Paulo (Brazil); Zahn, G.S.; Genezini, F.A.; Shorto, J.M.B. [Instituto de Pesquisas Energéticas e Nucleares (Brazil); Lubian, J.; Linares, R. [Instituto de Física da Universidade Federal Fluminense (Brazil); Toufen, D.L. [Instituto Federal de Educação, Ciência e Tecnologia (Brazil); Silveira, M.A.G. [Centro Universitário da FEI (Brazil); Rossi, E.S. [Centro Universitário FIEO – UNIFIEO (Brazil); Nobre, G.P. [Lawrence Livermore National Laboratory (United States)

    2014-06-01

    The Saci-Perere γ ray spectrometer (located at the Pelletron AcceleratorLaboratory – IFUSP) was employed to implement the γ-particle coincidence technique for the study of nuclear reaction mechanisms. For this, the {sup 18}O+{sup 110}Pd reaction has been studied in the beam energy range of 45–54 MeV. Several corrections to the data due to various effects (energy and angle integrations, beam spot size, γ detector finite size and the vacuum de-alignment) are small and well controlled. The aim of this work was to establish a proper method to analyze the data and identify the reaction mechanisms involved. To achieve this goal the inelastic scattering to the first excited state of {sup 110}Pd has been extracted and compared to coupled channel calculations using the São Paulo Potential (PSP), being reasonably well described by it.

  13. Nonelastic nuclear reactions induced by light ions with the BRIEFF code

    CERN Document Server

    Duarte, H

    2010-01-01

    The intranuclear cascade (INC) code BRIC has been extended to compute nonelastic reactions induced by light ions on target nuclei. In our approach the nucleons of the incident light ion move freely inside the mean potential of the ion in its center-of-mass frame while the center-of-mass of the ion obeys to equations of motion dependant on the mean nuclear+Coulomb potential of the target nucleus. After transformation of the positions and momenta of the nucleons of the ion into the target nucleus frame, the collision term between the nucleons of the target and of the ion is computed taking into account the partial or total breakup of the ion. For reactions induced by low binding energy systems like deuteron, the Coulomb breakup of the ion at the surface of the target nucleus is an important feature. Preliminary results of nucleon production in light ion induced reactions are presented and discussed.

  14. Microscopic approaches for nuclear Many-Body dynamics: applications to nuclear reactions

    CERN Document Server

    Simenel, Cédric; Lacroix, Denis

    2008-01-01

    These lecture notes are addressed to PhD student and/or researchers who want a general overview of microscopic approaches based on mean-field and applied to nuclear dynamics. Our goal is to provide a good description of low energy heavy-ion collisions. We present both formal aspects and practical applications of the time-dependent Hartree-Fock (TDHF) theory. The TDHF approach gives a mean field dynamics of the system under the assumption that particles evolve independently in their self-consistent average field. As an example, we study the fusion of both spherical and deformed nuclei with TDHF. We also focus on nucleon transfer which may occur between nuclei below the barrier. These studies allow us to specify the range of applications of TDHF in one hand, and, on the other hand, its intrinsic limitations: absence of tunneling below the Coulomb barrier, missing dissipative effects and/or quantum fluctuations. Time-dependent mean-field theories should be improved to properly account for these effects. Several ...

  15. Analysis on Japanese nuclear industrial technologies and their military implications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H. S.; Yang, M. H.; Kim, H. J. and others

    2000-10-01

    This study covered the following scopes : analysis of Japan's policy trend on the development and utilization of nuclear energy, international and domestic viewpoint of Japan's nuclear weapon capability, Japan's foreign affairs and international cooperation, status of Japan's nuclear technology development and its level, status and level of nuclear core technologies such as nuclear reactor and related fuel cycle technologies. Japan secures the whole spectrum of nuclear technologies including core technologies through the active implementation of nuclear policy for the peaceful uses of nuclear energy during the past five decades. Futhermore, as the result of the active cultivation of nuclear industry, Japan has most nuclear-related facilities and highly advanced nuclear industrial technologies. Therefore, it is reasonable that Japan might be recognized as one of countries having capability to get nuclear capability in several months.

  16. Nuclear fuel cycle facility accident analysis handbook

    International Nuclear Information System (INIS)

    The Accident Analysis Handbook (AAH) covers four generic facilities: fuel manufacturing, fuel reprocessing, waste storage/solidification, and spent fuel storage; and six accident types: fire, explosion, tornado, criticality, spill, and equipment failure. These are the accident types considered to make major contributions to the radiological risk from accidents in nuclear fuel cycle facility operations. The AAH will enable the user to calculate source term releases from accident scenarios manually or by computer. A major feature of the AAH is development of accident sample problems to provide input to source term analysis methods and transport computer codes. Sample problems and illustrative examples for different accident types are included in the AAH

  17. Nuclear fuel cycle facility accident analysis handbook

    Energy Technology Data Exchange (ETDEWEB)

    Ayer, J E; Clark, A T; Loysen, P; Ballinger, M Y; Mishima, J; Owczarski, P C; Gregory, W S; Nichols, B D

    1988-05-01

    The Accident Analysis Handbook (AAH) covers four generic facilities: fuel manufacturing, fuel reprocessing, waste storage/solidification, and spent fuel storage; and six accident types: fire, explosion, tornado, criticality, spill, and equipment failure. These are the accident types considered to make major contributions to the radiological risk from accidents in nuclear fuel cycle facility operations. The AAH will enable the user to calculate source term releases from accident scenarios manually or by computer. A major feature of the AAH is development of accident sample problems to provide input to source term analysis methods and transport computer codes. Sample problems and illustrative examples for different accident types are included in the AAH.

  18. Dynamic analysis of Leningrad nuclear power plant

    International Nuclear Information System (INIS)

    Within the scope of this study a preliminary dynamic analysis for the detonation explosion and earthquake load cases was carried out for the Leningrad Nuclear Power Plant. A soil model was added to the three-dimensional shell model which was taken over from IVO (Finland). During this Research Program the model was translated into the STARDYNE program and was investigated by means of time history modal analysis. Since the status quo of the documentation available at that time had to be completed through useful technical assumptions this report only considers exemplary selected results

  19. Distributed computing and nuclear reactor analysis

    International Nuclear Information System (INIS)

    Large-scale scientific and engineering calculations for nuclear reactor analysis can now be carried out effectively in a distributed computing environment, at costs far lower than for traditional mainframes. The distributed computing environment must include support for traditional system services, such as a queuing system for batch work, reliable filesystem backups, and parallel processing capabilities for large jobs. All ANL computer codes for reactor analysis have been adapted successfully to a distributed system based on workstations and X-terminals. Distributed parallel processing has been demonstrated to be effective for long-running Monte Carlo calculations

  20. The Nuclear Family: Correspondence in Cognitive and Affective Reactions to the Threat of Nuclear War among Older Adolescents and Their Parents.

    Science.gov (United States)

    Hamilton, Scott B.; And Others

    1986-01-01

    In order to assess the relationship between family members' cognitive and affective responses to nuclear war issues, 317 college students and their parents independently completed a multifaceted questionnaire that included items concerning personal reactions, predictions, opinions, and attitudes about nuclear war. (Author/LMO)

  1. MCNPX simulations of the silicon carbide semiconductor detector response to fast neutrons from D-T nuclear reaction

    Science.gov (United States)

    Sedlačková, Katarína; Šagátová, Andrea; Zat'ko, Bohumír; Nečas, Vladimír; Solar, Michael; Granja, Carlos

    2016-09-01

    Silicon Carbide (SiC) has been long recognized as a suitable semiconductor material for use in nuclear radiation detectors of high-energy charged particles, gamma rays, X-rays and neutrons. The nuclear interactions occurring in the semiconductor are complex and can be quantified using a Monte Carlo-based computer code. In this work, the MCNPX (Monte Carlo N-Particle eXtended) code was employed to support detector design and analysis. MCNPX is widely used to simulate interaction of radiation with matter and supports the transport of 34 particle types including heavy ions in broad energy ranges. The code also supports complex 3D geometries and both nuclear data tables and physics models. In our model, monoenergetic neutrons from D-T nuclear reaction were assumed as a source of fast neutrons. Their energy varied between 16 and 18.2 MeV, according to the accelerating voltage of the deuterons participating in D-T reaction. First, the simulations were used to calculate the optimum thickness of the reactive film composed of High Density PolyEthylene (HDPE), which converts neutral particles to charged particles and thusly enhancing detection efficiency. The dependency of the optimal thickness of the HDPE layer on the energy of the incident neutrons has been shown for the inspected energy range. Further, from the energy deposited by secondary charged particles and recoiled ions, the detector response was modeled and the effect of the conversion layer on detector response was demonstrated. The results from the simulations were compared with experimental data obtained for a detector covered by a 600 and 1300 μm thick conversion layer. Some limitations of the simulations using MCNPX code are also discussed.

  2. Quantitative differential thermal analysis study of the U3O8-Al thermite reaction

    International Nuclear Information System (INIS)

    Concerns about proliferation resistance of nuclear fuel cycles and fuels have prompted a reinvestigation of U3O8-Al cermet fuels currently being used in research and test reactors. In particular, higher loadings of U3O8 are being considered. These new fuel compositions are in the region of maximum possible thermal energy release from the high-temperature thermite reaction between the U3O8 and aluminum components. This study was initiated to quantitatively measure the amount of reaction heat evolved. A differential thermal analysis system was calibrated with materials of known heat of reaction. Subsequently, specimens of high-uranium-loaded U3O8-Al powder mixtures were analyzed. Thermite reaction heat measured for these specimens was much lower than expected. Specimens of simulated fuel plates showed similar low results. Possible reasons for this behavior are discussed

  3. Quantitative differential thermal analysis study of the U3O8-Al thermite reaction

    International Nuclear Information System (INIS)

    Concerns about proliferation resistance of nuclear fuel cycles and fuels have prompted a reinvestigation of U3O8-Al cermet fuels currently being used in research and test reactors. In particular, higher loadings of U3O8 are being considered. These new fuel compositions are in the region of maximum possible thermal energy release from the high-temperature thermite reaction between the U3O8 and aluminum components. This study was initiated to quantitatively measure the amount of reaction heat evolved. A differential thermal analysis system was calibrated with materials of known heat of reaction. Subsequently, specimens of high-uranium-loaded U3O8-Al powder mixtures were analyzed. Thermite reaction heat measured for these specimens was much lower than expected. Possible reason(s) for this behavior are discussed in the report

  4. NUCLEAR FORENSICS ANALYSIS CENTER FORENSIC ANALYSIS TO DATA INTERPRETATION

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, T.

    2011-02-07

    The Nuclear Forensics Analysis Center (NFAC) is part of Savannah River National Laboratory (SRNL) and is one of only two USG National Laboratories accredited to perform nuclear forensic analyses to the requirements of ISO 17025. SRNL NFAC is capable of analyzing nuclear and radiological samples from bulk material to ultra-trace samples. NFAC provides analytical support to the FBI's Radiological Evidence Examination Facility (REEF), which is located within SRNL. REEF gives the FBI the capability to perform traditional forensics on material that is radiological and/or is contaminated. SRNL is engaged in research and development efforts to improve the USG technical nuclear forensics capabilities. Research includes improving predictive signatures and developing a database containing comparative samples.

  5. Exergoeconomic analysis of a nuclear power plant

    Science.gov (United States)

    Moreno, Roman Miguel

    Exergoeconomic analysis of a nuclear power plant is a focus of this dissertation. Specifically, the performance of the Palo Verde Nuclear Power Plant in Arizona is examined. The analysis combines thermodynamic second law exergy analysis with economics in order to assign costs to the loss and destruction of exergy. This work was done entirely with an interacting spreadsheets notebook. The procedures are to first determine conventional energy flow, where the thermodynamic stream state points are calculated automatically. Exergy flow is then evaluated along with destruction and losses. The capital cost and fixed investment rate used for the economics do not apply specifically to the Palo Verde Plant. Exergy costing is done next involving the solution of about 90 equations by matrix inversion. Finally, the analysis assigns cost to the exergy destruction and losses in each component. In this work, the cost of electricity (exergy), including capital cost, leaving the generator came to 38,400 /hr. The major exergy destruction occurs in the reactor where fission energy transfer is limited by the maxiμm permissible clad temperature. Exergy destruction costs were: reactor--18,207 hr, the low pressure turbine-2,000 /hr, the condenser--1,700 hr, the steam generator-1,200 $/hr. The inclusion of capital cost and O&M are important in new system design assessments. When investigating operational performance, however, these are sunk costs; only fuel cost needs to be considered. The application of a case study is included based on a real modification instituted at Palo Verde to reduce corrosion steam generator problems; the pressure in the steam generator was reduced from 1072 to 980 psi. Exergy destruction costs increased in the low pressure turbine and in the steam generator, but decreased in the reactor vessel and the condenser. The dissertation demonstrates the procedures and tools required for exergoeconomic analysis whether in the evaluation of a new nuclear reactor system

  6. Nuclear spectrometry for environmental analysis and mapping

    International Nuclear Information System (INIS)

    Full text: The International Atomic Energy Agency (IAEA) helps countries to mobilize peaceful applications of nuclear science and technology. The three main pillars of the activities are: safety and security; science and technology; and safeguards and verification. As part of the science and technology pillar, the Physics Section supports Member States regarding utilization of particle accelerators and research reactors, applications of nuclear instrumentation, and controlled nuclear fusion research. Support is provided to the Member States in the form of capacity building, knowledge transfer and networking. The IAEA's coordinated research activities are designed to contribute to this mandate, by stimulating and coordinating research in IAEA Member States in selected nuclear fields. These coordinated research activities are normally implemented through Coordinated Research Projects that bring together research institutes from both developing and developed Member States to collaborate on the research topic of interest. The establishment of sustainable education and training programmes is fundamental for the safe, secure and efficient development of the nuclear field. The lAEA offers a wide spectrum of activities in support of education, training, human resource development and capacity building including interregional, regional and national training courses and workshops; assists visits and reviews services; initiates, formulates and runs programmes; networks managers and specialists for sharing good practices; assists in publications that compile the best international practices; supplies training materials and training tools; and supports internship programmes for the young generations of scientists and fellows. For the developing countries, the Technical Cooperation Programme provides the necessary skills and equipment to establish sustainable technology in the counterpart country or region through training courses, expert missions, fellowships, scientific

  7. High energy halogen atom reactions activated by nuclear transformations. Progress report, February 15, 1978--February 14, 1979

    International Nuclear Information System (INIS)

    High energy reactions of halogen atoms or ions, activated by nuclear transformations, were studied in gaseous, high pressure and condensed phase saturated and unsaturated hydrocarbons, halomethanes and other organic systems in order to better understand the mechanisms and dynamics of high energy monovalent species. The experimental and theoretical program consists of six interrelated areas: (1) the reactions of iodine with alkenes and alkynes activated by radiative neutron capture and isomeric transition in low pressure gaseous systems employing additives and rare gas moderators, high pressure and liquid systems; (2) the gas to condensed state transition in halogen high chemistry, involving bromine activated by the (n,γ) and (I.T.) processes in ethane was investigated in more detail; (3) systematics of halogen hot atom reactions. The reactions of 80Br/sup m/, 80Br, 82Br/sup m/ + 82Br, 82Br, 128I, 130I, and 130I/sup m/ + 130I activated by radiative neutron capture or isomeric transition in hydrocarbons and halo-substituted alkanes in low pressure and high pressure gaseous systems employing additives and rare gas moderators; (4) kinetic theory applications of high energy reactions and mathematical development of caging mechanisms were developed; (5) the sterochemistry of 38Cl substitution reactions involving diastereomeric 1,2-dichloro-1,2-difluorethane in liquid mixtures was completed, suggesting that the stereochemical course of the substitution process is controlled by the properties of the solvent molecules; and (6) the applications of high energy chemistry techniques and theory to neutron activation analysis of biological systems was continued, especially involving aluminum and vanadium trace determinations

  8. Coupled seismic analysis of nuclear safety systems

    International Nuclear Information System (INIS)

    Seismic responses of structural systems obtained on the basis of coupled analysis (selected equipment modelled along with the civil structures) results in lower responses and economical designs when compared with uncoupled analysis. For Nuclear Safety Related Structures, from considerations of limiting problem size for analysis and also to reduce modelling efforts, it is necessary to select which equipment needs to be modelled with its supports so as to adequately obtain the response of the structural system with interaction of such equipment. Coupled analysis of a primary structure and secondary system is necessary when the effects of interaction between them are significant. This paper attempts to study the structural response of Reactor Building structures of PHWR as well as PFBR to arrive at specific conclusions with respect to effect of coupling of secondary systems. The paper presents an approach followed to evolve a rational basis for inclusion or non-inclusion of such equipment in the coupled model of the primary system. (author)

  9. Advancing the Theory of Nuclear Reactions with Rare Isotopes. From the Laboratory to the Cosmos

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Filomena [Michigan State Univ., East Lansing, MI (United States)

    2015-06-01

    The mission of the Topical Collaboration on the Theory of Reactions for Unstable iSotopes (TORUS) was to develop new methods to advance nuclear reaction theory for unstable isotopes—particularly the (d,p) reaction in which a deuteron, composed of a proton and a neutron, transfers its neutron to an unstable nucleus. After benchmarking the state-of-the-art theories, the TORUS collaboration found that there were no exact methods to study (d,p) reactions involving heavy targets; the difficulty arising from the long-range nature of the well known, yet subtle, Coulomb force. To overcome this challenge, the TORUS collaboration developed a new theory where the complexity of treating the long-range Coulomb interaction is shifted to the calculation of so-called form-factors. An efficient implementation for the computation of these form factors was a major achievement of the TORUS collaboration. All the new machinery developed are essential ingredients to analyse (d,p) reactions involving heavy nuclei relevant for astrophysics, energy production, and stockpile stewardship.

  10. Reaction of reference commercial nuclear waste glasses during gamma irradiation in a saturated tuff environment

    International Nuclear Information System (INIS)

    The effects of gamma irradiation on groundwater and the reaction between groundwater and glass have been investigated at radiation exposure rates of 2 x 105 , 1 x 103 , and 0 R/h. These experiments, which bound the conditions that may occur in a high-level nuclear waste repository located in tuff, have been performed using the actinide-containing glasses ATM-1c and ATM-8, and have been performed for time periods up to 278 days. The experimental results indicate that when only the repository groundwater is present, the pH of the system remains near-neutral, regardless of the radiation field, due to the buffering capacity of the solution. When glass is added to the system, the subsequent reaction is governed by the solution chemistry, which results from a complex interaction between radiolysis products, glass reaction products, and groundwater components. While no long-term reaction trends have been extracted from the current data, it is noted that there are no outstanding differences in the reaction of the glasses as measured by the release of the soluble components B, Mo, and Na, as a function of radiation exposure rate. However, there is a marked difference in the amount of U, Np, and Pu released from the glasses as a function of radiation exposure rate. This difference can be correlated with the pH values of the leachate, with more basic solutions resulting in lower actinide release

  11. Trends in nuclear systems design and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Casini, G. (Commission of the European Communities, Joint Research Centre/Ispra Establishment, Inst. for Systems Engineering and Design (Italy))

    1991-12-01

    The papers presented at the poster session 'Nuclear Systems Design and Analyses' are reviewed and trends discussed. The attention is focussed on the following areas: (i) Reactor Studies and (ii) Neutronic Tests and Analysis. Present studies on D-T power reactor conceptual designs should be encouraged. Recent conceptual studies on D-{sup 3}He systems seem adequate to identify the critical issues. The economic feasibility of {sup 3}He supply from the moon should be assessed. Contributions on Neutronics are found to be of particular relevance and represent an important step towards the implementation of data base for nuclear design of plasma facing and breeding blanket components. (orig.).

  12. Analysis of nuclear-power construction costs

    International Nuclear Information System (INIS)

    This paper discusses the use of regression analysis for estimating construction costs. The estimate is based on an historical data base and quantification of key factors considered external to project management. This technique is not intended as a replacement for detailed cost estimates but can provide information useful to the cost-estimating process and to top management interested in evaluating project management. The focus of this paper is the nuclear-power construction industry but the technique is applicable beyond this example. The approach and critical assumptions are also useful in a public-policy situation where utility commissions are evaluating construction in prudence reviews and making comparisons to other nuclear projects. 13 references, 2 figures

  13. The Trojan Horse method for nuclear astrophysics: Recent results on resonance reactions

    Energy Technology Data Exchange (ETDEWEB)

    Cognata, M. La; Pizzone, R. G. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania (Italy); Spitaleri, C.; Cherubini, S.; Romano, S. [Dipartimento di Fisica e Astronomia, Università di Catania, Catania, Italy and Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania (Italy); Gulino, M.; Tumino, A. [Kore University, Enna, Italy and Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania (Italy); Lamia, L. [Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy)

    2014-05-09

    Nuclear astrophysics aims to measure nuclear-reaction cross sections of astrophysical interest to be included into models to study stellar evolution and nucleosynthesis. Low energies, < 1 MeV or even < 10 keV, are requested for this is the window where these processes are more effective. Two effects have prevented to achieve a satisfactory knowledge of the relevant nuclear processes, namely, the Coulomb barrier exponentially suppressing the cross section and the presence of atomic electrons. These difficulties have triggered theoretical and experimental investigations to extend our knowledge down to astrophysical energies. For instance, indirect techniques such as the Trojan Horse Method have been devised yielding new cutting-edge results. In particular, I will focus on the application of this indirect method to resonance reactions. Resonances might dramatically enhance the astrophysical S(E)-factor so, when they occur right at astrophysical energies, their measurement is crucial to pin down the astrophysical scenario. Unknown or unpredicted resonances might introduce large systematic errors in nucleosynthesis models. These considerations apply to low-energy resonances and to sub-threshold resonances as well, as they may produce sizable modifications of the S-factor due to, for instance, destructive interference with another resonance.

  14. Microscopic calculations of the characteristics of radiative nuclear reactions for double-magic nuclei

    Directory of Open Access Journals (Sweden)

    Achakovskiy Oleg

    2016-01-01

    Full Text Available The neutron capture cross sections and average radiative widths Γγ of neutron resonances for two double-magic nuclei 132Sn and 208Pb have been calculated using the microscopic photon strength functions (PSF, which were obtained within the microscopic self-consistent version of the extended theory of finite Fermi systems in the time blocking approximation. For the first time, the microscopic PSFs have been obtained within the fully self-consistent approach with exact accounting for the single particle continuum (for 208Pb. The approach includes phonon coupling effects in addition to the standard RPA approach. The known Skyrme force has been used. The calculations of nuclear reaction characteristics have been performed with the EMPIRE 3.1 nuclear reaction code. Here, three nuclear level density (NLD models have been used: the so-called phenomenological GSM, the EMPIRE specific (or Enhanced GSM and the microscopical combinatorial HFB NLD models. For both considered characteristics we found a significant disagreement between the results obtained with the GSM and HFB NLD models. For 208Pb, a reasonable agreement has been found with systematic for the Γγ values with HFB NLD and with the experimental data for the HFB NLD average resonance spacing D0, while for these two quantities the differences between the values obtained with GSM and HFB NLD are of several orders of magnitude. The discrepancies between the results with the phenomenological EGLO PSF and microscopic RPA or TBA are much less for the same NLD model.

  15. Heavy-ion double charge exchange reactions: A tool toward 0 νββ nuclear matrix elements

    Energy Technology Data Exchange (ETDEWEB)

    Cappuzzello, F.; Bondi, M. [Universita di Catania, Dipartimento di Fisica e Astronomia, Catania (Italy); INFN, Laboratori Nazionali del Sud, Catania (Italy); Cavallaro, M.; Agodi, C.; Carbone, D.; Cunsolo, A. [INFN, Laboratori Nazionali del Sud, Catania (Italy); Foti, A. [Universita di Catania, Dipartimento di Fisica e Astronomia, Catania (Italy); INFN, Sezione di Catania, Catania (Italy)

    2015-11-15

    The knowledge of the nuclear matrix elements for the neutrinoless double beta decay is fundamental for neutrino physics. In this paper, an innovative technique to extract information on the nuclear matrix elements by measuring the cross section of a double charge exchange nuclear reaction is proposed. The basic point is that the initial- and final-state wave functions in the two processes are the same and the transition operators are similar. The double charge exchange cross sections can be factorized in a nuclear structure term containing the matrix elements and a nuclear reaction factor. First pioneering experimental results for the {sup 40}Ca({sup 18}O,{sup 18}Ne){sup 40}Ar reaction at 270 MeV incident energy show that such cross section factorization reasonably holds for the crucial 0{sup +} → 0{sup +} transition to {sup 40}Ar{sub gs}, at least at very forward angles. (orig.)

  16. Heavy-ion double charge exchange reactions: a tool towards 0v\\b{eta}\\b{eta} nuclear matrix elements

    CERN Document Server

    Cappuzzello, F; Agodi, C; Bond`ı, M; Carbone, D; Cunsolo, A; Foti, A

    2015-01-01

    The knowledge of the nuclear matrix elements for the neutrinoless double beta decay is fundamental for neutrino physics. In this paper, an innovative technique to extract information on the nuclear matrix elements by measuring the cross section of a double charge exchange nuclear reaction is proposed. The basic point is that the initial and final state wave functions in the two processes are the same and the transition operators are similar. The double charge exchange cross sections can be factorized in a nuclear structure term containing the matrix elements and a nuclear reaction factor. First pioneering experimental results for the 40Ca(18O,18Ne)40Ar reaction at 270 MeV incident energy show that such cross section factorization reasonably holds for the crucial 0+ --> 0+ transition to 40Args, at least at very forward angles.

  17. Theoretical Analysis on I-S Influence to Water Thermolysis Temperature in Nuclear Hydrogen Production

    International Nuclear Information System (INIS)

    The abundant amount of energy which is resulted from nuclear reaction has been used to generate electricity, powering aircraft ships, submarine and many others application. In spite of those utilities, the thermal efficiency of nuclear reactor is only 30 %. To increase the efficiency and flexibility, the nuclear energy could be converted to be a hydrogen fuel. The use of hydrogen fuel will be a solution for two global issues at once i.e., to anticipate the shortening of oil reserve and to stop the global warming. The use of nuclear heat increases the possibility of hydrogen production in a massive scale. Through water thermolysis, the nuclear energy which is released as heat can be altered to form a chemical energy which is kept in hydrogen molecules. When it is required, the energy can be released again by oxidizing these hydrogens. Hydrogen is a very gracious fuel for the environment because its waste is water. But a direct water thermolysis reaction should meet a very high temperature of 5,000 °C which caused many difficulties. Therefore, it is well known in the last recent years an indirect technique for water thermolysis through a series of reactions which can be carried out at lower temperature. The reactions form a closed cycle with I-S (Iodine-Sulphure) catalyst as a mediator so that the technique is called I-S cycle. This paper contains theorytical analysis on I-S (Iodine-Sulphure) cycle influence to the temperature lowering in water thermolysis reaction for hydrogen production which exploites the heat of nuclear reaction in a NPS (Nuclear (Generated) Power Station). Thermodynamic variables determination showed that the indirect water thermolysis through I-S catalized reaction cycle can be carried out spontantly at a relatively low temperature, i.e. 900 °C maximally. (author)

  18. Sealing analysis for nuclear vessel of PWR

    International Nuclear Information System (INIS)

    Although design by analysis of pressure vessel has become a requirement in all codes for more than 20 years, sealing design for nuclear components is still too complicated and there are yet no criteria about this aspect, even though in the well-known ASME Boiler and Pressure Vessel Code. Thus it is of significance to undertake researches of transient sealing tests and analysis for nuclear vessel. Since 1960s great progress has been made in analytic computer program, which takes flange as a rigid ring. Actually, however, there are elastic or elastoplastic contacts on flange mating surface. Chen (1979) gave a mixed finite element method, using a condensing flexible matrix skill, to solve two-body contact problem. On the basis of axisymmetric stress and thermal analysis of finite element method and on accepting Chen's (1979) idea of mixed finite element method, we have developed a computer program for sealing analysis, named SMEC, which considers bolt loading changes and temperature effects. (orig./GL)

  19. Diffusion induced nuclear reactions in metals: a possible source of heat in the core

    International Nuclear Information System (INIS)

    It has recently been proposed that diffusion of light nuclei in metals can give rise to unusual electrical charge distributions in their lattice structures, inducing thereby certain nuclear reactions that are otherwise uncommon. In the light of these results we advance the hypothesis that such nuclear reactions take place in the metal rich core of the earth, based on following observations: 1 - The solubility of hydrogen in metals is relatively high compared to that in silicates. 2 - Studies of rare gas samples in intraplate volcanos and diamonds show that 3He/ He ratio increases with depth in the mantle. 3 - There are indications that He is positively correlated with enrichment of metals in lavas. We propose that hydrogen incorporated into metallic phases at the time of planetary accretion was carried to the core by downward migration of metal rich melts during the early states of proto-earth. Preliminary estimates suggest that cold fusion reactions can give rise to an average rate of heat generation of 8.2x1012 W and may thus serve as a supplementary source of energy for the geomagnetic dynamo. (author)

  20. The use of low energy, ion induced nuclear reactions for proton radiotherapy applications

    International Nuclear Information System (INIS)

    Medical radiotherapy has traditionally relied upon the use of external photon beams and internally implanted radioisotopes as the chief means of irradiating tumors. However, advances in accelerator technology and the exploitation of novel means of producing radiation may provide useful alternatives to some current modes of medical radiation delivery with reduced total dose to surrounding healthy tissue, reduced expense, or increased treatment accessibility. This paper will briefly overview currently established modes of radiation therapy, techniques still considered experimental but in clinical use, innovative concepts under study that may enable new forms of treatment or enhance existing ones. The potential role of low energy, ion-induced nuclear reactions in radiotherapy applications is examined specifically for the 650 keV d(3He,p)4He nuclear reaction. This examination will describe the basic physics associated with this reaction's production of 17.4 MeV protons and the processes used to fabricate the necessary materials used in the technique. Calculations of the delivered radiation dose, heat generation, and required exposure times are presented. Experimental data are also presented validating the dose calculations. The design of small, lower cost ion accelerators, as embodied in 'nested'-tandem and radio frequency quadrupole accelerators is examined, as is the potential use of high-output 3He and deuterium ion sources. Finally, potential clinical applications are discussed in terms of the advantages and disadvantages of this technique with respect to current radiotherapy methods and equipment

  1. Momentum-space approach to nuclear reaction studies: opportunities and perspectives

    International Nuclear Information System (INIS)

    The application of momentum-space three- and four-body scattering equations to the description of nuclear reactions involving systems of three and four nucleons is reviewed, and major achievements and challenges are identified. The calculations include realistic state-of-the-art interactions between nucleon pairs, together with the Coulomb interaction between protons. The effect of including three- and four-nucleon forces is discussed. Further calculations are shown involving the study of nuclear reactions where three-body degrees of freedom play a significant role. These studies involve not just an attempt to describe data in terms of a full three-body model that is solved numerically in a converged way, but also to use this exact framework to validade and test the accuracy of approximate reaction methods such as continuum discretized coupled channel (CDCC), distorted wave impulse approximation (DWIA), plane-wave impulse approximation (PWIA) and the Glauber multiple scattering approach. These comparisons are able to teach researchers under which conditions approximate methods can be used to extract important structural information about exotic nuclei. Prospects and challenges are discussed. (paper)

  2. Strong screening effects on resonant nuclear reaction 23Mg (p, γ) 24Al in the surface of magnetars

    Science.gov (United States)

    Liu, Jing-Jing

    2016-05-01

    Based on the theory of relativistic superstrong magnetic fields (SMFs), by using the method of Thomas-Fermi-Dirac approximations, we investigate the problem of strong electron screening (SES) in SMFs and the influence of SES on the nuclear reaction of 23Mg (p, γ)24Al. Our calculations show that the nuclear reaction will be markedly effected by the SES in SMFs in the surface of magnetars. Our calculated screening rates can increase two orders of magnitude due to SES in SMFs.

  3. Nuclear clusters as a probe for expansion flow in heavy ion reactions at 10-15A GeV

    CERN Document Server

    Mattiello, R; Stöcker, H; Greiner, W

    1996-01-01

    A phase space coalescence description based on the Wigner-function method for cluster formation in relativistic nucleus-nucleus collisions is presented. The momentum distributions of nuclear clusters d,t and He are predicted for central Au(11.6AGeV)Au and Si(14.6AGeV)Si reactions in the framework of the RQMD transport approach. Transverse expansion leads to a strong shoulder-arm shape and different inverse slope parameters in the transverse spectra of nuclear clusters deviating markedly from thermal distributions. A clear ``bounce-off'' event shape is seen: the averaged transverse flow velocities in the reaction plane are for clusters larger than for protons. The cluster yields --particularly at low p_t at midrapidities-- and the in-plane (anti)flow of clusters and pions change if suitably strong baryon potential interactions are included. This allows to study the transient pressure at high density via the event shape analysis of nucleons, nucleon clusters and other hadrons.

  4. New exclusive CHIPS-TPT algorithms for simulation of neutron-nuclear reactions

    Science.gov (United States)

    Kosov, M.; Savin, D.

    2015-05-01

    The CHIPS-TPT physics library for simulation of neutron-nuclear reactions on the new exclusive level is being developed in CFAR VNIIA. The exclusive modeling conserves energy, momentum and quantum numbers in each neutron-nuclear interaction. The CHIPS-TPT algorithms are based on the exclusive CHIPS library, which is compatible with Geant4. Special CHIPS-TPT physics lists in the Geant4 format are provided. The calculation time for an exclusive CHIPS-TPT simulation is comparable to the time of the corresponding Geant4- HP simulation. In addition to the reduction of the deposited energy fluctuations, which is a consequence of the energy conservation, the CHIPS-TPT libraries provide a possibility of simulation of the secondary particles correlation, e.g. secondary gammas, and of the Doppler broadening of gamma lines in the spectrum, which can be measured by germanium detectors.

  5. Reactions of psychiatric patients to the Three Mile Island nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Bromet, E.; Schulberg, H.C.; Dunn, L.

    1982-06-01

    The reaction of patients in the community mental health system to the nuclear accident at Three Mile Island (TMI), Middletown, Pa, were assessed. The sample was composed of 151 patients from the TMI area and 64 patients from a comparison site where a similar nuclear plant is located. Mental health status was determined for the period immediately after the accident, nine to ten months later, and one year later. No significant differences were found between the TMI group and the comparison group. To isolate risk factors within the TMI group, patients who were most distressed were compared with patients with the least distress. The results showed that quality of network support and viewing TMI as dangerous were significantly associated with mental health.

  6. Unified description of structure and reactions: implementing the Nuclear Field Theory program

    CERN Document Server

    Broglia, Ricardo A; Barranco, Francisco; Vigezzi, Enrico; Idini, Andrea; Potel, Gregory

    2015-01-01

    The modern theory of the atomic nucleus results from the merging of the liquid drop (Niels Bohr and Fritz Kalckar) and of the shell model (Marie Goeppert Meyer and Axel Jensen), which contributed the concepts of collective excitations and of independent-particle motion respectively. The unification of these apparently contradictory views in terms of the particle-vibration (rotation) coupling (Aage Bohr and Ben Mottelson) has allowed for an ever increasingly complete, accurate and detailed description of the nuclear structure, Nuclear Field Theory (NFT, developed by the Copenhagen-Buenos Aires collaboration) providing a powerful quantal embodiment. In keeping with the fact that reactions are not only at the basis of quantum mechanics (statistical interpretation, Max Born) , but also the specific tools to probe the atomic nucleus, NFT is being extended to deal with processes which involve the continuum in an intrinsic fashion, so as to be able to treat them on an equal footing with those associated with discret...

  7. Low Energy Nuclear Reaction Aircraft- 2013 ARMD Seedling Fund Phase I Project

    Science.gov (United States)

    Wells, Douglas P.; McDonald, Robert; Campbell, Robbie; Chase, Adam; Daniel, Jason; Darling, Michael; Green, Clayton; MacGregor, Collin; Sudak, Peter; Sykes, Harrison; Waddington, Michael; Fredericks, William J.; Lepsch, Roger A.; Martin, John G.; Moore, Mark D.; Zawodny, Joseph M.; Felder, James L.; Snyder, Christopher A.

    2014-01-01

    This report serves as the final written documentation for the Aeronautic Research Mission Directorate (ARMD) Seedling Fund's Low Energy Nuclear Reaction (LENR) Aircraft Phase I project. The findings presented include propulsion system concepts, synergistic missions, and aircraft concepts. LENR is a form of nuclear energy that potentially has over 4,000 times the energy density of chemical energy sources. It is not expected to have any harmful emissions or radiation which makes it extremely appealing. There is a lot of interest in LENR, but there are no proven theories. This report does not explore the feasibility of LENR. Instead, it assumes that a working system is available. A design space exploration shows that LENR can enable long range and high speed missions. Six propulsion concepts, six missions, and four aircraft concepts are presented. This report also includes discussion of several issues and concerns that were uncovered during the study and potential research areas to infuse LENR aircraft into NASA's aeronautics research.

  8. Experimental cross-sections for proton-induced nuclear reactions on natMo

    Science.gov (United States)

    Červenák, Jaroslav; Lebeda, Ondřej

    2016-08-01

    In the framework of the Co-ordinated Research Project of the IAEA, we measured in detail cross-sections of the nuclear reactions natMo(p,x)93gTc, 93mTc, 93m+gTc, 94gTc, 94mTc, 95gTc, 95mTc, 96m+gTc, 97mTc, 99mTc, 90Mo, 93mMo, 99Mo, 88gNb, 88mNb, 89gNb, 89mNb, 90m+gNb, 90m+gNbcum, 91mNb, 92mNb, 95gNb, 95mNb, 95m+gNb, 96Nb, 97m+gNb, 88m+gZrcum and 89m+gZrcum in the energy range of 6.9-35.8 MeV. The data for formation of 97mTc, 88gNb, 88mNb and 89mNb are reported for the first time. The obtained results were compared to the prediction of the nuclear reaction model code TALYS adopted from the TENDL-2015 library and to the previously published cross-sections. The thick target yields for all the radionuclides were calculated from the measured data. We suggest recommended cross-sections and thick target yields for the 100Mo(p,2n)99mTc, 100Mo(p,x)99Mo and natMo(p,x)96m+gTc nuclear reactions deduced from the selected experimental data.

  9. Nuclear reactions with radioactive and stable beams (Part I); Reacciones nucleares con haces radiactivos y estables (Parte I)

    Energy Technology Data Exchange (ETDEWEB)

    Aguilera R, E.F.; Martinez Q, E.; Gomez C, A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2004-12-15

    At the present time there is a great interest at world level in experiments, with accelerated nuclei of short half life. The dispersion, fusion, transfer and break processes in the interaction of weakly light projectiles bounded with targets of Z great its have been object of intense recent investigation, at world level. Our group, in collaboration with the University of Notre Dame, it has measured and analyzed these processes for weakly bound systems as: {sup 6}He + {sup 209}Bi, {sup 8}Li + {sup 208}Pb, {sup 10}Be + {sup 208}Pb. On the other hand a research line that has wakened up great interest, it is that of studies of resonant reactions using the Inverse Kinematics technique with thick targets. The use of this technique allows to measure an entire excitation function with a single bombardment. Our group has carried out, in the ININ, preliminary bombardments for the system {sup 12}C + {sup 4}He. This allowed to establish the feasibility of implementing this technique in our Laboratory. The application of this and other techniques to different systems like {sup 18}O + {sup 4}He, {sup 12}C + {sup 12}C, {sup 12}C + {sup 16}O, {sup 16}O + {sup 16}O, it opens the possibility to measure the fusion of these systems at very low energy and to deepen in the knowledge of the nuclear structure and the nuclear astrophysics. In this technical report, the activities carried out by our group during 2004 are described.(Author)

  10. From low- to high-energy nuclear data evaluations. Issues and perspectives on nuclear reaction models and covariances

    International Nuclear Information System (INIS)

    Evaluation of neutron cross sections between 0eV and 20MeV is based on several aspects of nuclear physics such as nuclear reaction and structure models and microscopic and integral measurements. Most of the time, the evaluation process is separately done in the resolved resonance range and the continuum. It may give rise to non-physical mismatches of cross sections and large uncertainties at boundaries. It also leads to an absence of cross correlations between high-energy domain and resonance range. In addition, integral experiments are sometimes only used to check central values (evaluation is ''working fine'' on a dedicated set of benchmarks). Eventual reduction of uncertainties on cross sections is not straightforward: ''working fine'' could be mathematically turned into reduced uncertainties. This paper will present several ideas that could be used to avoid such effects. They are based on basic physical principles, recent advances in terms of covariance evaluation methodologies, intensive use of Monte Carlo methods and High Performance Computing (HPC) and on some newly introduced models. A clear connection is made between resonance and continuum energy ranges. (orig.)

  11. A sensitivity study of s-process: the impact of uncertainties from nuclear reaction rates

    Science.gov (United States)

    Vinyoles, N.; Serenelli, A.

    2016-01-01

    The slow neutron capture process (s-process) is responsible for the production of about half the elements beyond the Fe-peak. The production sites and the conditions under which the different components of s-process occur are relatively well established. A detailed quantitative understanding of s-process nucleosynthesis may yield light in physical processes, e.g. convection and mixing, taking place in the production sites. For this, it is important that the impact of uncertainties in the nuclear physics is well understood. In this work we perform a study of the sensitivity of s-process nucleosynthesis, with particular emphasis in the main component, on the nuclear reaction rates. Our aims are: to quantify the current uncertainties in the production factors of s-process elements originating from nuclear physics and, to identify key nuclear reactions that require more precise experimental determinations. In this work we studied two different production sites in which s-process occurs with very different neutron exposures: 1) a low-mass extremely metal-poor star during the He-core flash (nn reaching up to values of ∼ 1014cm-3); 2) the TP-AGB phase of a M⊙, Z=0.01 model, the typical site of the main s-process component (nn up to 108 — 109cm-3). In the first case, the main variation in the production of s-process elements comes from the neutron poisons and with relative variations around 30%-50%. In the second, the neutron poison are not as important because of the higher metallicity of the star that actually acts as a seed and therefore, the final error of the abundances are much lower around 10%-25%.

  12. Risk and safety analysis of nuclear systems

    CERN Document Server

    Lee, John C

    2011-01-01

    The book has been developed in conjunction with NERS 462, a course offered every year to seniors and graduate students in the University of Michigan NERS program. The first half of the book covers the principles of risk analysis, the techniques used to develop and update a reliability data base, the reliability of multi-component systems, Markov methods used to analyze the unavailability of systems with repairs, fault trees and event trees used in probabilistic risk assessments (PRAs), and failure modes of systems. All of this material is general enough that it could be used in non-nuclear a

  13. Obtention of differential sections in nuclear reactions using a thick target; Obtencion de secciones diferenciales en reacciones nucleares usando un blanco grueso

    Energy Technology Data Exchange (ETDEWEB)

    Chavez R, R

    2000-07-01

    The nuclear reaction analysis (NRA) technique is used mainly for detecting the presence and concentration of light elements of great importance such as: carbon, nitrogen and oxygen. This work has the objective to obtain the differential sections of {sup 16} O and {sup 14} N starting from the irradiation with deuterons of TiSrO{sub 3} samples, of AIN and AIN{sub 2} at energies of 2000 KeV and 1800 KeV respectively. The present work have four chapters; chapter 1 is focused to the physical aspects which takes part in the NRA technique. The technical requirements as well as the necessary equipment for developing the techniques are described in the chapter 2. In chapter 3 it is described the algorithm developed for to obtain the differential sections starting from experimental data, and finally, in chapter 4 are given the results and conclusions. (Author)

  14. Report on the IAEA technical meeting on network of nuclear reaction data centres

    International Nuclear Information System (INIS)

    This report summarizes the IAEA Technical Meeting on the Network of Nuclear Reaction Data Centres (biennial Data Centre Heads Meeting), held at the Brookhaven National Laboratory, Upton, NY, USA from 4-7 October 2004. The meeting was attended by 20 participants from 11 co-operating data centres of six Member States and two International Organizations. The report contains a summary of the meeting, the conclusions and actions, status reports of the participating data centres, and a revised technical protocol for the cooperation of the network. (author)

  15. Comparison between the entropy approach and Monte Carlo calculations for statistical nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, H.M.; Mertelmeier, T. (Erlangen-Nuernberg Univ., Erlangen (Germany, F.R.). Inst. fuer Theoretische Physik); Mello, P.A. (Instituto Nacional de Investigaciones Nucleares, Mexico City. Lab. del Acelerador); Seligman, T.H. (Universidad Nacional Autonoma de Mexico, Mexico City. Inst. de Fisica)

    1981-12-14

    A comparison is presented between predictions of the entropy approach to statistical nuclear reactions, and numerical calculations performed by generating an ensemble of S-matrices in terms of K-matrices with specified statistical distributions for their parameters. The comparison is done for: (a) the 2nd, 3rd and 4th moments of S in a 4-channel case and (b) the actual distribution of the S-matrix elements in a 2-channel case. In both cases the agreement is found to be very good in the domain of strong absorption.

  16. COMMENTS ON "A NEW LOOK AT LOW-ENERGY NUCLEAR REACTION RESEARCH"

    Energy Technology Data Exchange (ETDEWEB)

    Shanahan, K.

    2009-12-30

    Cold fusion researchers have accumulated a large body of anomalous results over the last 20 years that they claim proves a new, mysterious nuclear reaction is active in systems they study. Krivit and Marwan give a brief and wholly positive view of this body of research. Unfortunately, cold fusion researchers routinely ignore conventional explanations of their observations, and claim much greater than real accuracy and precision for their techniques. This paper attempts to equally briefly address those aspects of the field with the intent of providing a balanced view of the field, and to establish some criteria for subsequent publications in this arena.

  17. Experimental tests of recent nuclear models with the (n,γ) reaction

    International Nuclear Information System (INIS)

    The nonselectivity of the (n,γ) reaction provides a powerful tool for the study of those nuclear models of broad applicability whose characteristic excitations span a wide range of degrees of freedom. Several recent examples of this are discussed with particular emphasis on the recent discovery of the 0(6) limit of the interacting boson model and of a new interpretation of the Pt--0s transition region which consequently emerges. Other topics considered include recent extensions of the Nilsson model to new regions of nucleus, excitation energy and complexity of states. 43 references

  18. Spin dipole nuclear matrix elements for double beta decay nuclei by charge-exchange reactions

    CERN Document Server

    Ejiri, H

    2016-01-01

    Spin dipole (SD) strengths for double beta-decay (DBD) nuclei were studied experimentally for the first time by using measured cross sections of (3He,t) charge exchange reactions (CERs). Then SD nuclear matrix elements (NMEs) for low-lying 2- states were derived from the experimental SD strengths by referring to the experimental GT (Gamow-Teller) and F (Fermi) strengths. They are consistent with the empirical SD NMEs based on the quasi-particle model with the empirical effective SD coupling constant. The CERs are used to evaluate the SD NME, which is associated with one of the major components of the neutrino-less DBD NME.

  19. Nuclear excitations and reaction mechanisms: a research proposal (renewal) and report of progress

    International Nuclear Information System (INIS)

    Research progress is reported on the following subjects: (1) diamagnetism, gauge transformations and sum rules, (2) quantal motion in an electric field, (3) a theorem concerning quadrupole absorption and scattering of photons, (4) excitation of natural parity states by Raman scattering in nuclei, (5) retarded E1 transitions and isoscaler giant dipole resonances, (6) low energy photon scattering from nuclei, (7) few-body models of nuclear reactions, (8) three- and four-nucleon configuration space calculations, (9) time-dependent few-body calculations, (10) atomic and molecular structure calculations, (11) bound state approximations, (12) extended Faddeev theory, (13) configuration-space techniques, and (14) time-dependent approach to scattering problems

  20. Activation cross sections of proton induced nuclear reactions on palladium up to 80 MeV

    CERN Document Server

    Tárkányi, F; Takács, S; Csikai, J; Hermanne, A; Uddin, S; Baba, M

    2016-01-01

    Activation cross sections of proton induced nuclear reactions on palladium were measured up to 80 MeV by using the stacked foil irradiation technique and gamma ray spectrometry. The beam intensity, the incident energy and the energy degradation were controlled by a method based on flux constancy via normalization to the excitation functions of monitor reactions measured in parallel. Excitation functions for direct and cumulative cross-sections were measured for the production of ${}^{104m,104g,105}$${}^{g,106m,110m}$Ag, ${}^{100,101}$Pd, ${}^{99m,99g,100,}$${}^{101m}$${}^{,101g,102m,102g,105}$Rh and ${}^{103,}$${}^{97}$Ru radioisotopes. The cross section data were compared with the theoretical predictions of TENDL-2014 and -2015 libraries. For practical applications thick target yields were derived from the measured excitation functions. Application in the field of medical radionuclide production is shortly discussed.

  1. Activation cross sections of proton induced nuclear reactions on ytterbium up to 70 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Tarkanyi, F. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), 4026 Debrecen, Bem ter 18/c (Hungary); Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel (VUB), 1090 Brussels (Belgium); Takacs, S.; Ditroi, F. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), 4026 Debrecen, Bem ter 18/c (Hungary); Kiraly, B. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), 4026 Debrecen, Bem ter 18/c (Hungary)], E-mail: kiralyb@atomki.hu; Yamazaki, H.; Baba, M.; Mohammadi, A. [Cyclotron and Radioisotope Center (CYRIC), Tohoku University, Sendai 980-8578 (Japan); Ignatyuk, A.V. [Institute of Physics and Power Engineering (IPPE), Obninsk 249020 (Russian Federation)

    2009-09-01

    Cross sections of proton induced nuclear reactions on ytterbium were measured up to 70 MeV by using the standard stacked foil irradiation technique and high-resolution gamma-ray spectroscopy. Experimental cross sections and derived integral yields are reported for the first time for the {sup nat}Yb(p,xn){sup 173,172mg,171mg,170,167}Lu, {sup nat}Yb(p,x){sup 175cum,166cum}Yb and {sup nat}Yb(p,x){sup 173ind,172ind,168,167cum,165cum}Tm reactions. No earlier experimental cross section data were found in the literature. The experimental data were compared to and analyzed with the results of the theoretical model code ALICE-IPPE. Production routes of medical radioisotope {sup 167}Tm are discussed.

  2. Program POD. A computer code to calculate cross sections for neutron-induced nuclear reactions

    International Nuclear Information System (INIS)

    A computer code, POD, was developed for neutron-induced nuclear data evaluations. This program is based on four theoretical models, (1) the optical model to calculate shape-elastic scattering and reaction cross sections, (2) the distorted wave Born approximation to calculate neutron inelastic scattering cross sections, (3) the preequilibrium model, and (4) the multi-step statistical model. With this program, cross sections can be calculated for reactions (n, γ), (n, n'), (n, p), (n, α), (n, d), (n, t), (n, 3He), (n, 2n), (n, np), (n, nα), (n, nd), and (n, 3n) in the neutron energy range above the resonance region to 20 MeV. The computational methods and input parameters are explained in this report, with sample inputs and outputs. (author)

  3. Light particle emission as a probe of reaction mechanism and nuclear excitation

    International Nuclear Information System (INIS)

    The central part of these lectures will be dealing with the problem of energy dissipation. A good understanding of the mechanisms for the dissipation requires to study both peripheral and central collisions or, in other words, to look at the impact paramenter dependence. This should also provide valuable information on the time scale. In order to probe the reaction mechanism and nuclear excitation, one of the most powerful tool is unquestionably the observation of light particle emission, including neutrons and charged particles. Several examples will be discussed related to peripheral collisions (the fate of transfer reactions, the excitation energy generation, the production of projectile-like fragments) as well as inner collisions for which extensive studies have demonstrated the strength of intermediate energy heavy ions for the production of very hot nuclei and detailed study of their decay properties

  4. A semi-classical theory of multi-step nuclear reaction processes

    International Nuclear Information System (INIS)

    The master equation theory of precompound and compound nuclear reaction has been generalized to the inclusion of the conservation of angular momentum and parity. This improved semi-classical theory has been extended for application as an evaluation tool of the calculations of nucleon induced reaction cross sections and double differential cross sections. For structural materials at incident neutron energies below 20 MeV, it is demonstrated that the constructed model contains the Hauser-Feshbach, Weisskopf-Ewing as well as the exciton models as limiting cases. The unified treatment of pre-equilibrium processes includes a number of interesting features, such as the exciton state densities with the exact Pauli exclusion correction which are renormalized to the back-shifted Fermi-gas formula; the introduction of formation factors of composite particle in calculations of pick-up type composite particle emission and the double differential cross sections for all kinds of particles in terms of the leading particle model

  5. The total cross sections of heavy ion reaction and the nuclear transfer

    International Nuclear Information System (INIS)

    The total reaction cross section of the systems 12C + 12C, 12C + 40Ca, 12C + 90Zr, 12C + 208Pb, 40Ca + 40Ca, 40Ca + 208Pb + 90Zr + 90Zr, 90Zr + 208Pb and 208Pb + 208Pb for a wide range of energies has been calculated microscopically. A WKB expression for the imaginary phase shift in the impact paremeter representation has been employed. The imaginary part of the optical potential has been constructed by using the first term of multiple scattering theory with the effect of Pauli blocking incorporated into it. The inclusion of the nuclear and Coulomb interactions is shown to be important. The theoretical results do not show very good agreement with the experimental data at lower energies. This is attributed to the weak absorption contained in the imaginary potential of the ''tοA οB'' interaction, wich contained only quasifree knock-out as the dominant reaction mechanism. (author)

  6. STARLIB: A Next-Generation Reaction-Rate Library for Nuclear Astrophysics

    CERN Document Server

    Sallaska, A L; Champagne, A E; Goriely, S; Starrfield, S; Timmes, F X

    2013-01-01

    STARLIB is a next-generation, all-purpose nuclear reaction-rate library. For the first time, this library provides the rate probability density at all temperature grid points for convenient implementation in models of stellar phenomena. The recommended rate and its associated uncertainties are also included. Currently, uncertainties are absent from all other rate libraries, and, although estimates have been attempted in previous evaluations and compilations, these are generally not based on rigorous statistical definitions. A common standard for deriving uncertainties is clearly warranted. STARLIB represents a first step in addressing this deficiency by providing a tabular, up-to-date database that supplies not only the rate and its uncertainty but also its distribution. Because a majority of rates are lognormally distributed, this allows the construction of rate probability densities from the columns of STARLIB. This structure is based on a recently suggested Monte Carlo method to calculate reaction rates, w...

  7. Activation cross sections of proton induced nuclear reactions on palladium up to 80MeV.

    Science.gov (United States)

    Tárkányi, F; Ditrói, F; Takács, S; Csikai, J; Hermanne, A; Uddin, M S; Baba, M

    2016-08-01

    Activation cross sections of proton induced nuclear reactions on palladium were measured up to 80MeV by using the stacked foil irradiation technique and gamma ray spectrometry. The beam intensity, the incident energy and the energy degradation were controlled by a method based on flux constancy via normalization to the excitation functions of monitor reactions measured in parallel. Excitation functions for direct and cumulative cross-sections were measured for the production of (104m,104g,105g,106m,110m)Ag, (100,101)Pd, (99m,99g,100,101m,101g,102m,102g,105)Rh and (103,97)Ru radioisotopes. The cross section data were compared with the theoretical predictions of TENDL-2014 and -2015 libraries. For practical applications thick target yields were derived from the measured excitation functions. Application in the field of medical radionuclide production is shortly discussed. PMID:27235887

  8. SABRE: A Tool for Stochastic Analysis of Biochemical Reaction Networks

    CERN Document Server

    Didier, Frederic; Mateescu, Maria; Wolf, Verena

    2010-01-01

    The importance of stochasticity within biological systems has been shown repeatedly during the last years and has raised the need for efficient stochastic tools. We present SABRE, a tool for stochastic analysis of biochemical reaction networks. SABRE implements fast adaptive uniformization (FAU), a direct numerical approximation algorithm for computing transient solutions of biochemical reaction networks. Biochemical reactions networks represent biological systems studied at a molecular level and these reactions can be modeled as transitions of a Markov chain. SABRE accepts as input the formalism of guarded commands, which it interprets either as continuous-time or as discrete-time Markov chains. Besides operating in a stochastic mode, SABRE may also perform a deterministic analysis by directly computing a mean-field approximation of the system under study. We illustrate the different functionalities of SABRE by means of biological case studies.

  9. Mathematics analysis of polymerase chain reaction kinetic curves.

    Science.gov (United States)

    Sochivko, D G; Fedorov, A A; Varlamov, D A; Kurochkin, V E; Petrov, R V

    2016-01-01

    The paper reviews different approaches to the mathematical analysis of polymerase chain reaction (PCR) kinetic curves. The basic principles of PCR mathematical analysis are presented. Approximation of PCR kinetic curves and PCR efficiency curves by various functions is described. Several PCR models based on chemical kinetics equations are suggested. Decision criteria for an optimal function to describe PCR efficiency are proposed.

  10. Study for Nuclear Structures of 22-35Na Isotopes via Measurements of Reaction Cross Sections

    Science.gov (United States)

    Suzuki, Shinji

    2014-09-01

    T. Ohtsubo, M. Nagashima, T. Ogura, Y. Shimbara (Grad. Sch. of Sc., Niigata Univ.), M.Takechi, H. Geissel, M. Winkler (GSI), D. Nishimura, T. Sumikama (Dept. of Phys., Tokyo Univ. of Sc.), M. Fukuda, M. Mihara, H. Uenishi (Dept. of Phys., Osaka Univ.), T. Kuboki, T. Suzuki, T. Yamaguchi, H. Furuki, C. S. Lee, K. Sato (Dept. of Phys., Saitama Univ.), A. Ozawa, H. Ohnishi, T. Moriguchi, S. Fukuda, Y. Ishibashi, D. Nagae, R. Nishikiori, T. Niwa (Inst. of Phys., Univ. of Tsukuba), N. Aoi (RCNP), Rui-Jiu Chen, N. Inabe, D. Kameda, T. Kubo, M. Lantz, T. Ohnishi, K. Okumura, H. Sakurai, H. Suzuki, H. Takeda, S. Takeuchi, K. Tanaka, Y. Yanagisawa (RIKEN), De-Qing Fang, Yu-Gang Ma (SINAP), T. Izumikawa (RI Ctr., Niigata Univ.), and S. Momota (Fac. of Engn., Kochi Univ. of Tech.) Reaction cross sections (σR) for 22-35Na isotopes have been measured at around 240 MeV/nucleon. The σR for 22-35Na were measured for the first time. Enhancement in cross sections is clearly observed from the systematics for stable nuclei, for isotopes with large mass numbers. These enhancement can be mainly ascribed to the nuclear deformation. We will discuss the nuclear structure (neutron skin, nuclear shell structure) for neutron-excess Na isotopes. T. Ohtsubo, M. Nagashima, T. Ogura, Y. Shimbara (Grad. Sch. of Sc., Niigata Univ.), M.Takechi, H. Geissel, M. Winkler (GSI), D. Nishimura, T. Sumikama (Dept. of Phys., Tokyo Univ. of Sc.), M. Fukuda, M. Mihara, H. Uenishi (Dept. of Phys., Osaka Univ.), T. Kuboki, T. Suzuki, T. Yamaguchi, H. Furuki, C. S. Lee, K. Sato (Dept. of Phys., Saitama Univ.), A. Ozawa, H. Ohnishi, T. Moriguchi, S. Fukuda, Y. Ishibashi, D. Nagae, R. Nishikiori, T. Niwa (Inst. of Phys., Univ. of Tsukuba), N. Aoi (RCNP), Rui-Jiu Chen, N. Inabe, D. Kameda, T. Kubo, M. Lantz, T. Ohnishi, K. Okumura, H. Sakurai, H. Suzuki, H. Takeda, S. Takeuchi, K. Tanaka, Y. Yanagisawa (RIKEN), De-Qing Fang, Yu-Gang Ma (SINAP), T. Izumikawa (RI Ctr., Niigata Univ.), and S. Momota (Fac. of Engn

  11. Numerical Analysis of Microwave Heating on Saponification Reaction

    Science.gov (United States)

    Huang, Kama; Jia, Kun

    2005-01-01

    Currently, microwave is widely used in chemical industry to accelerate chemical reactions. Saponification reaction has important applications in industry; some research results have shown that microwave heating can significantly accelerate the reaction [1]. But so far, no efficient method has been reported for the analysis of the heating process and design of an efficient reactor powered by microwave. In this paper, we present a method to study the microwave heating process on saponification reaction, where the reactant in a test tube is considered as a mixture of dilute solution. According to the preliminary measurement results, the effective permittivity of the mixture is approximately the permittivity of water, but the conductivity, which could change with the reaction, is derived from the reaction equation (RE). The electromagnetic field equation and reaction equation are coupled by the conductivity. Following that, the whole heating processes, which is described by Maxwell's equations, the reaction equation and heat transport equation (HTE), is analyzed by finite difference time domain (FDTD) method. The temperature rising in the test tube are measured and compared with the computational results. Good agreement can be seen between the measured and calculated results.

  12. Computational methods for nuclear criticality safety analysis

    International Nuclear Information System (INIS)

    Nuclear criticality safety analyses require the utilization of methods which have been tested and verified against benchmarks results. In this work, criticality calculations based on the KENO-IV and MCNP codes are studied aiming the qualification of these methods at the IPEN-CNEN/SP and COPESP. The utilization of variance reduction techniques is important to reduce the computer execution time, and several of them are analysed. As practical example of the above methods, a criticality safety analysis for the storage tubes for irradiated fuel elements from the IEA-R1 research has been carried out. This analysis showed that the MCNP code is more adequate for problems with complex geometries, and the KENO-IV code shows conservative results when it is not used the generalized geometry option. (author)

  13. Decision Analysis For Nuclear Fuel Cycle Policy

    International Nuclear Information System (INIS)

    The prime objective in this talk is to explore the impact of widely different (or hypothetical) fuel cycle requirement rather than to attempt to predict a probable scenario. In the course of preparation of this talk, it was realized that, despite the very speculative nature of this kind of endeavor, studies like these are considered essential to the long-range planning needs of the national nuclear power industry, utilities and those providing supporting services, even though the current presentation are extremely primitive in that purpose. A nuclear electricity utility tries to reduce fuel cycle costs. But the problems have to be approached with a long-term perspective, and the logical conclusion is that utility has to make technical progress. As nuclear generation gradually become great, supplies of the fuel cycle services are responsible for the R and D about the nuclear fuel cycle services which is useful to implement the technical choices they propose. Then it is for the utility to choose according to his knowledge, if necessary by carrying out additional research. But only the utility acquires real operating experience and prototype reactor or laboratory tests offer limited knowledge quantities. One way to ensure a good guarantee of supply is, obviously, to make the order far enough ahead of time to have a stock. But, on the other hand, stocks are expensive and should be kept to a strict minimum. Therefore, a detailed analysis of uncertainties is required, as well as an effort to optimize the handling of the overall problem. As mentioned earlier, in recent years, specifically the right way to handle the back-end of the fuel cycle has been always hotly contested and ultimately it was a question of reprocessing or direct disposal of spent fuel elements. Direct disposal of spent fuel is, at present, the only possibility of spent fuel disposal option available to the Korean utility. Korea, having virtually no indigenous uranium resources, can hardly afford to

  14. Risk analysis in nuclear energy use

    International Nuclear Information System (INIS)

    In nuclear energy like other energy sources risk is present. The risk assessment and comparison with proposed risk criteria in nuclear energy user country, need to be measured for nuclear power plant site selection, construction, operation and maintenance. Experience of long-term nuclear energy user countries need to be used in the risk assesment and criteria creation. In article are shown results of risk assessment in many human activities. Nuclear power plants accidents categorization is given. There are accidents shown which occurred at nuclear power plants. Basic information about probabilistic risk assessment in nuclear power plant site evaluation are given. (author)

  15. Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR.

    Science.gov (United States)

    Balzan, Riccardo; Fernandes, Laetitia; Comment, Arnaud; Pidial, Laetitia; Tavitian, Bertrand; Vasos, Paul R

    2016-01-01

    The main limitation of NMR-based investigations is low sensitivity. This prompts for long acquisition times, thus preventing real-time NMR measurements of metabolic transformations. Hyperpolarization via dissolution DNP circumvents part of the sensitivity issues thanks to the large out-of-equilibrium nuclear magnetization stemming from the electron-to-nucleus spin polarization transfer. The high NMR signal obtained can be used to monitor chemical reactions in real time. The downside of hyperpolarized NMR resides in the limited time window available for signal acquisition, which is usually on the order of the nuclear spin longitudinal relaxation time constant, T1, or, in favorable cases, on the order of the relaxation time constant associated with the singlet-state of coupled nuclei, TLLS. Cellular uptake of endogenous molecules and metabolic rates can provide essential information on tumor development and drug response. Numerous previous hyperpolarized NMR studies have demonstrated the relevancy of pyruvate as a metabolic substrate for monitoring enzymatic activity in vivo. This work provides a detailed description of the experimental setup and methods required for the study of enzymatic reactions, in particular the pyruvate-to-lactate conversion rate in presence of lactate dehydrogenase (LDH), by hyperpolarized NMR. PMID:26967906

  16. Nuclear structure and reaction mechanism effects in quasi continuum gamma decay

    International Nuclear Information System (INIS)

    In this thesis an investigation of nuclear structure and reaction mechanism effects is presented as they manifest themselves in the gamma-ray quasi-continua of residual nuclei produced in 12C induced reactions. The author has studied the nuclear structure at high angular momentum and excitation energy of two heavy nuclei (152Dy,156Dy) that have a very different structure at low angular momentum and excitation energy. In addition the effect of the quasi-continuous gamma-decay process on the feeding of the yrast states (the states with the lowest excitation energy at a certain angular momentum) in these two rare earth nuclei has been investigated. The results are discussed in terms of collective and non-collective excitation modes. The interplay between these two types of motion of the nucleons in nuclei in the same mass region and its influence on the structure of the yrast states has been investigated in a search for high-spin isomeric states. (Auth.)

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

    CERN Document Server

    Giuffrida, L; Cirrone, G A P; Picciotto, A; Korn, G

    2016-01-01

    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 [1], 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 demonstr...

  18. Unified description of structure and reactions: implementing the nuclear field theory program

    Science.gov (United States)

    Broglia, R. A.; Bortignon, P. F.; Barranco, F.; Vigezzi, E.; Idini, A.; Potel, G.

    2016-06-01

    The modern theory of the atomic nucleus results from the merging of the liquid drop model of Niels Bohr and Fritz Kalckar, and of the shell model of Marie Goeppert Meyer and Hans Jensen. The first model contributed the concepts of collective excitations. The second, those of independent-particle motion. The unification of these apparently contradictory views in terms of the particle-vibration and particle-rotation couplings carried out by Aage Bohr and Ben Mottelson has allowed for an ever more complete, accurate and detailed description of nuclear structure. Nuclear field theory (NFT), developed by the Copenhagen-Buenos Aires collaboration, provided a powerful quantal embodiment of this unification. Reactions are not only at the basis of quantum mechanics (statistical interpretation, Max Born), but also the specific tools to probe the atomic nucleus. It is then natural that NFT is being extended to deal with processes which involve the continuum in an intrinsic fashion, so as to be able to treat them on an equal footing with those associated with bound states (structure). As a result, spectroscopic studies of transfer to continuum states could eventually make use of the NFT rules, properly extended to take care of recoil effects. In the present contribution we review the implementation of the NFT program of structure and reactions, setting special emphasis on open problems and outstanding predictions.

  19. An image analyzer system for the analysis of nuclear traces

    International Nuclear Information System (INIS)

    Inside the project of nuclear traces and its application techniques to be applied in the detection of nuclear reactions of low section (non detectable by conventional methods), in the study of accidental and personal neutron dosemeters, and other but, are developed. All these studies are based on the fact that the charged particles leave latent traces of dielectric that if its are engraved with appropriate chemical solutions its are revealed until becoming visible to the optical microscope. From the analysis of the different trace forms, it is possible to obtain information of the characteristic parameters of the incident particles (charge, mass and energy). Of the density of traces it is possible to obtain information of the flow of the incident radiation and consequently of the received dose. For carry out this analysis has been designed and coupled different systems, that it has allowed the solution of diverse outlined problems. Notwithstanding it has been detected that to make but versatile this activity is necessary to have an Image Analyzer System that allow us to digitize, to process and to display the images with more rapidity. The present document, presents the proposal to carry out the acquisition of the necessary components for to assembling an Image Analyzing System, like support to the mentioned project. (Author)

  20. Reaction sintered glass: a durable matrix for spinel-forming nuclear waste compositions

    International Nuclear Information System (INIS)

    Glass formation by reaction sintering under isostatic pressure is an innovative process to vitrify refractory-rich high-level radioactive waste. We used a typical defense waste composition, containing spinel-forming components such as ∼4 wt% of Cr2O3, ∼23 wt% Al2O3, ∼13 wt% Fe2O3, and ∼9 wt% UO2, with CeO2 simulating UO2. Reaction sintered silicate glasses with waste loading up to 45 wt% were prepared within three hours, by hot pressing at 800 deg. C. The glass former was amorphous silica. Simulated waste was added as calcined oxides. The reaction sintered glass samples were characterized using scanning and analytical electron microscopy. The results show that extensive reaction sintering took place and a continuous glass phase formed. Waste components such as Na2O, CaO, MnO2, and Fe2O3, dissolved completely in the continuous glass phase. Cr2O3, Al2O3, and CeO2 were only partially dissolved due to incomplete dissolution (Al2O3) or super-saturation and reprecipitation (Cr2O3 and CeO2). The precipitation mechanism is related to a time dependent alkali content in the developing glass phase. Short-term corrosion tests in water showed that the glasses are chemically more durable than melted nuclear waste glasses. Based on hydration energies calculations, the long-term chemical durability of our reaction sintered glasses is expected to be comparable to that of rhyolitic and tektite glasses

  1. Compositional change of some first wall materials by considering multiple step nuclear reaction

    Energy Technology Data Exchange (ETDEWEB)

    Noda, Tetsuji; Utsumi, Misako; Fujita, Mitsutane [National Research Inst. for Metals, Tsukuba, Ibaraki (Japan)

    1997-03-01

    The conceptual system for nuclear material design is considered and some trials on WWW server with functions of the easily accessible simulation of nuclear reactions are introduced. Moreover, as an example of the simulation on the system using nuclear data, transmutation calculation was made for candidate first wall materials such as 9Cr-2W steel, V-5Cr-5Ti and SiC in SUS316/Li{sub 2}O/H{sub 2}O(SUS), 9Cr-2WLi{sub 2}O/H{sub 2}O(RAF), V alloy/Li/Be(V), and SiC/Li{sub 2}ZrO{sub 3}/He(SiC) blanket/shield systems based on ITER design model. Neutron spectrum varies with different blanket/shield compositions. The flux of low energy neutrons decreases in order of V-SiC-RAF-SUS blanket/shield systems. Fair amounts of W depletion in 9Cr-2W steel and the increase of Cr content in V-5Cr-5Ti were predicted in SUS or RAF systems. Concentration change in W and Cr is estimated to be suppressed if Li coolant is used in place of water. Helium and hydrogen production are not strongly affected by the different blanket/shield compositions. (author)

  2. Summary report of second research coordination meeting on parameters for calculation of nuclear reactions of relevance to non-energy nuclear application (Reference Input Parameter Library: Phase III)

    International Nuclear Information System (INIS)

    A summary is given of the Second Research Coordination Meeting on Parameters for Calculation of Nuclear Reactions of Relevance to Non-Energy Nuclear Applications (Reference Input Parameter Library: Phase III), including a review of the various work undertaken by participants. The new RIPL-3 library should serve as input for theoretical calculations of nuclear reaction data at incident energies up to 200 MeV, as needed for energy and non-energy modern applications of nuclear data. Significant progress was achieved in defining the contents of the RIPL-3 library. Technical discussions and the resulting work plan of the Coordinated Research Programme are summarized, along with actions and deadlines. Participants' summary reports at the RCM are also included in this report. (author)

  3. Nuclear reactions with radioactive and stable beams (Part II); Reacciones nucleares con haces radiactivos y estables (Parte II)

    Energy Technology Data Exchange (ETDEWEB)

    Aguilera R, E.F.; Martinez Q, E.; Gomez C, A.; Lizcano, D. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2005-12-15

    At the present time there is a great interest at world level in experiments, with accelerated nuclei of short half life. The dispersion, fusion, transfer and break processes in the interaction of weakly light projectiles bounded with targets of Z great its have been object of intense recent investigation, at world level. Our group, in collaboration with the University of Notre Dame, it has measured and analyzed these processes for weakly bound systems as: {sup 6}He + {sup 209}Bi, {sup 8}Li + {sup 208}Pb, {sup 10}Be + {sup 208}Pb. On the other hand a research line that has wakened up great interest, it is that of studies of resonant reactions using the Inverse Kinematics technique with thick targets. The use of this technique allows to measure an entire excitation function with a single bombardment. Our group has carried out, in the ININ, preliminary bombardments for the system {sup 12}C + {sup 4}He. This allowed to establish the feasibility of implementing this technique in our Laboratory. The application of this and other techniques to different systems like {sup 18}O + {sup 4}He, {sup 12}C + {sup 12}C, {sup 12}C + {sup 16}O, {sup 16}O + {sup 16}O, it opens the possibility to measure the fusion of these systems at very low energy and to deepen in the knowledge of the nuclear structure and the nuclear astrophysics. In this technical report, the activities carried out by our group during the second stage of this project, considered for 2005 are described. Also in that year, our group carries out a research stay in the University of Notre Dame, during this stay, the angular distribution of the projectiles of {sup 8}B dispersed in an enriched target of {sup 58}Ni was measured. The same as in the previous experiments, in this occasion it was also possible to measure those angular distributions of the projectiles of {sup 7}Be and {sup 6}Li dispersed in this same target. In this same one our stay group participates in other three experiments proposed by collaborators of

  4. A study on the nuclear foreign policy analysis

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Keun Bae; Choi, Y. M.; Lee, D. J.; Lee, K. S.; Lee, B. W.; Cho, I. H.; Ko, H. S.

    1996-12-01

    This study aims to analyses recent trends of international situation relating to nuclear non-proliferation and the adverse conditions in Korea`s pursuing self-support of such technology, so that it may map out effective strategies for the promotion of nuclear energy. This study analyses developments of international nuclear non-proliferation regime, which plays a main role in preventing the international proliferation of nuclear weapons. This study includes NPT, IAEA safeguards system, international export control regimes, CTBT, and NWFZs as the subjects of analysis. Second theme is international organizations concerning nuclear activities. This study mainly analyses IAEA activities which pursues the promotion of peaceful use of nuclear energy and nuclear non-proliferation simultaneously as a pivotal body of international nuclear cooperation. Third focus of this study is Northeast Asian circumstances pertaining to nuclear non-proliferation. The study looks into the DPRK nuclear issues, and reviews the developments of the proposed regional body for nuclear cooperation and the discussion on the Northeast Asian NWFZ. Fourth, but the most influential to Korean nuclear activities, is the U. S. nuclear policy, since U. S. takes the overwhelming initiative in the field of international nuclear non-proliferation. Therefore, this study gives much weight in analyzing the structure, procedures, recent trend, and pending issues of U. S. nuclear policy. (author). 78 refs., 5 tabs., 4 figs.

  5. A study on the nuclear foreign policy analysis

    International Nuclear Information System (INIS)

    This study aims to analyses recent trends of international situation relating to nuclear non-proliferation and the adverse conditions in Korea's pursuing self-support of such technology, so that it may map out effective strategies for the promotion of nuclear energy. This study analyses developments of international nuclear non-proliferation regime, which plays a main role in preventing the international proliferation of nuclear weapons. This study includes NPT, IAEA safeguards system, international export control regimes, CTBT, and NWFZs as the subjects of analysis. Second theme is international organizations concerning nuclear activities. This study mainly analyses IAEA activities which pursues the promotion of peaceful use of nuclear energy and nuclear non-proliferation simultaneously as a pivotal body of international nuclear cooperation. Third focus of this study is Northeast Asian circumstances pertaining to nuclear non-proliferation. The study looks into the DPRK nuclear issues, and reviews the developments of the proposed regional body for nuclear cooperation and the discussion on the Northeast Asian NWFZ. Fourth, but the most influential to Korean nuclear activities, is the U. S. nuclear policy, since U. S. takes the overwhelming initiative in the field of international nuclear non-proliferation. Therefore, this study gives much weight in analyzing the structure, procedures, recent trend, and pending issues of U. S. nuclear policy. (author). 78 refs., 5 tabs., 4 figs

  6. Development in the field of heavy ion physics at the Flerov Laboratory of Nuclear Reactions

    CERN Document Server

    Itkis, M G; Popeko, A G

    2001-01-01

    A unique research base with modern set-ups (kinematic separators, 4 pi-spectrometers of charged particles, detectors of neutron and gamma-quanta) has been created at the FLNR on the basis of the U-400 and U-400M isochronous cyclotrons. A program on the synthesis of superheavy elements in the region of predicted spherical shells with Z approx = 114 and N approx = 184 has been launched. First experiments aimed at the synthesis of the nuclei with Z = 112, 114 and 116 have been carried out using sup 4 sup 8 Ca+ sup 2 sup 3 sup 8 U, sup 4 sup 8 Ca+ sup 2 sup 4 sup 2 sup , sup 2 sup 4 sup 4 Pu and sup 4 sup 8 Ca+ sup 2 sup 4 sup 8 Cm reactions. New results on the properties of Rf and Sg have been obtained. New evidence of the shell influence on the nuclear fission dynamics has been obtained. A number of experiments devoted to the study of reaction mechanism in nucleus-nucleus collisions were carried out. Manifestations of the sup 6 He-nucleus structure in elastic scattering and transfer reactions between sup 6 He a...

  7. Towards a nonequilibrium Green's function description of nuclear reactions: one-dimensional mean-field dynamics

    CERN Document Server

    Rios, Arnau; Buchler, Mark; Danielewicz, Pawel

    2010-01-01

    Nonequilibrium Green's function methods allow for an intrinsically consistent description of the evolution of quantal many-body body systems, with inclusion of different types of correlations. In this paper, we focus on the practical developments needed to build a Green's function methodology for nuclear reactions. We start out by considering symmetric collisions of slabs in one dimension within the mean-field approximation. We concentrate on two issues of importance for actual reaction simulations. First, the preparation of the initial state within the same methodology as for the reaction dynamics is demonstrated by an adiabatic switching on of the mean-field interaction, which leads to the mean-field ground state. Second, the importance of the Green's function matrix-elements far away from the spatial diagonal is analyzed by a suitable suppression process that does not significantly affect the evolution of the elements close to the diagonal. The relative lack of importance of the far-away elements is tied t...

  8. Analysis of nuclear power plant construction costs

    International Nuclear Information System (INIS)

    The objective of this report is to present the results of a statistical analysis of nuclear power plant construction costs and lead-times (where lead-time is defined as the duration of the construction period), using a sample of units that entered construction during the 1966-1977 period. For more than a decade, analysts have been attempting to understand the reasons for the divergence between predicted and actual construction costs and lead-times. More importantly, it is rapidly being recognized that the future of the nuclear power industry rests precariously on an improvement in the cost and lead-time situation. Thus, it is important to study the historical information on completed plants, not only to understand what has occurred to also to improve the ability to evaluate the economics of future plants. This requires an examination of the factors that have affected both the realized costs and lead-times and the expectations about these factors that have been formed during the construction process. 5 figs., 22 tabs

  9. Safety analysis of nuclear fuel transport

    International Nuclear Information System (INIS)

    The thermal and structural analysis methods have been improved their efficiency for safety assessments of nuclear fuel transport casks. The pressure-based coupled method recently incorporated in the FLUENT code has been confirmed that it can greatly reduce the calculation time of long term temperature transient analyses for the cask fireproof tests. The parallel computing technique has been investigated for impact load analyses and it is found that by using 32-cores parallel system, the computing time reduces to around 1/10. The pressure-based coupled method and the parallel computing technique will be applied to future expected cross-check analyses and contribute to enhance the quality of the safety evaluation by increasing the number of examination cases. (author)

  10. Economic Analysis of Investment in Nuclear Weapons

    OpenAIRE

    Martínková, Hana

    2015-01-01

    Nuclear weapons are a rather marginal issue in economics as opposed to the political realm where it is an ever-present topic concerning global security. This thesis argues that economics can make a valuable contribution to the nuclear weapons debate in several ways and aims to present those in a comprehensive manner. First, a cost-benefit approach is employed to show that costs and benefits go beyond counting dollars directly spent on nuclear arsenals. Second, market investment in nuclear wea...

  11. STARLIB: A Next-generation Reaction-rate Library for Nuclear Astrophysics

    Science.gov (United States)

    Sallaska, A. L.; Iliadis, C.; Champange, A. E.; Goriely, S.; Starrfield, S.; Timmes, F. X.

    2013-07-01

    STARLIB is a next-generation, all-purpose nuclear reaction-rate library. For the first time, this library provides the rate probability density at all temperature grid points for convenient implementation in models of stellar phenomena. The recommended rate and its associated uncertainties are also included. Currently, uncertainties are absent from all other rate libraries, and, although estimates have been attempted in previous evaluations and compilations, these are generally not based on rigorous statistical definitions. A common standard for deriving uncertainties is clearly warranted. STARLIB represents a first step in addressing this deficiency by providing a tabular, up-to-date database that supplies not only the rate and its uncertainty but also its distribution. Because a majority of rates are lognormally distributed, this allows the construction of rate probability densities from the columns of STARLIB. This structure is based on a recently suggested Monte Carlo method to calculate reaction rates, where uncertainties are rigorously defined. In STARLIB, experimental rates are supplemented with: (1) theoretical TALYS rates for reactions for which no experimental input is available, and (2) laboratory and theoretical weak rates. STARLIB includes all types of reactions of astrophysical interest to Z = 83, such as (p, γ), (p, α), (α, n), and corresponding reverse rates. Strong rates account for thermal target excitations. Here, we summarize our Monte Carlo formalism, introduce the library, compare methods of correcting rates for stellar environments, and discuss how to implement our library in Monte Carlo nucleosynthesis studies. We also present a method for accessing STARLIB on the Internet and outline updated Monte Carlo-based rates.

  12. STARLIB: A NEXT-GENERATION REACTION-RATE LIBRARY FOR NUCLEAR ASTROPHYSICS

    Energy Technology Data Exchange (ETDEWEB)

    Sallaska, A. L. [National Institute of Standards and Technology, Gaithersburg, MD 20899-8462 (United States); Iliadis, C.; Champange, A. E. [University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3255 (United States); Goriely, S. [Institut d' Astronomie et d' Astrophysique, Universite Libre de Bruxelles, C.P. 226, B-1050 Brussels (Belgium); Starrfield, S.; Timmes, F. X., E-mail: anne.sallaska@nist.gov [Arizona State University, Tempe, AZ 85287-1504 (United States)

    2013-07-15

    STARLIB is a next-generation, all-purpose nuclear reaction-rate library. For the first time, this library provides the rate probability density at all temperature grid points for convenient implementation in models of stellar phenomena. The recommended rate and its associated uncertainties are also included. Currently, uncertainties are absent from all other rate libraries, and, although estimates have been attempted in previous evaluations and compilations, these are generally not based on rigorous statistical definitions. A common standard for deriving uncertainties is clearly warranted. STARLIB represents a first step in addressing this deficiency by providing a tabular, up-to-date database that supplies not only the rate and its uncertainty but also its distribution. Because a majority of rates are lognormally distributed, this allows the construction of rate probability densities from the columns of STARLIB. This structure is based on a recently suggested Monte Carlo method to calculate reaction rates, where uncertainties are rigorously defined. In STARLIB, experimental rates are supplemented with: (1) theoretical TALYS rates for reactions for which no experimental input is available, and (2) laboratory and theoretical weak rates. STARLIB includes all types of reactions of astrophysical interest to Z = 83, such as (p, {gamma}), (p, {alpha}), ({alpha}, n), and corresponding reverse rates. Strong rates account for thermal target excitations. Here, we summarize our Monte Carlo formalism, introduce the library, compare methods of correcting rates for stellar environments, and discuss how to implement our library in Monte Carlo nucleosynthesis studies. We also present a method for accessing STARLIB on the Internet and outline updated Monte Carlo-based rates.

  13. Group theoretical analysis of the H3+ +H2 ↔ H5+ reaction

    Science.gov (United States)

    Lin, Zhou

    2016-06-01

    The H3+ +H2 →H2 + H3+ proton transfer reaction is complicated due to the proton scrambling from the large amplitude motions in the H5+ intermediate. In order to understand this reaction, high-resolution spectroscopic studies are necessary for the reactants/products and the intermediate, and the group theoretical analysis is an essential aspect in the prediction and interpretation of these spectra. With five indistinguishable protons, H5+ is characterized using the G240 complete nuclear permutation-inversion (CNPI) group. For most of the configurations sampled by the reaction path, the feasible permutations depend on the distance between the H3+ and H2 fragments. Subgroups of G240 can be used to describe these feasible permutations. Specifically, we consider two limits of the molecular configurations. The equilibrium structure of H5+ , i.e., [H2 -H -H2 ]+, can be described using the G16 molecular symmetry group, while the dissociation products, i.e., H3+ ⋯H2 , require the G24 molecular symmetry group. In the present study, a group theoretical analysis is performed for both limits, providing the symmetries for the nuclear spins and rovibrational wave functions. Also, spectroscopic properties for [H2 -H -H2 ]+, particularly rovibrational couplings and electric dipole selection rules, as well as correlations of energy levels between [H2 -H -H2 ]+ and H3+ ⋯H2 , are obtained.

  14. Improvement on reaction model for sodium-water reaction jet code and application analysis

    International Nuclear Information System (INIS)

    In selecting the reasonable DBL on steam generator (SG), it is necessary to improve analytical method for estimating the sodium temperature on failure propagation due to overheating. Improvement on sodium-water reaction (SWR) jet code (LEAP-JET ver.1.30) and application analysis to the water injection tests for confirmation of code propriety were performed. On the improvement of the code, a gas-liquid interface area density model was introduced to develop a chemical reaction model with a little dependence on calculation mesh size. The test calculation using the improved code (LEAP-JET ver.1.40) were carried out with conditions of the SWAT-3·Run-19 test and an actual scale SG. It is confirmed that the SWR jet behavior on the results and the influence to analysis result of a model are reasonable. For the application analysis to the water injection tests, water injection behavior and SWR jet behavior analyses on the new SWAT-1 (SWAT-1R) and SWAT-3 (SWAT-3R) tests were performed using the LEAP-BLOW code and the LEAP-JET code. In the application analysis of the LEAP-BLOW code, parameter survey study was performed. As the results, the condition of the injection nozzle diameter needed to simulate the water leak rate was confirmed. In the application analysis of the LEAP-JET code, temperature behavior of the SWR jet was investigated. (author)

  15. Improvement on reaction model for sodium-water reaction jet code and application analysis

    Energy Technology Data Exchange (ETDEWEB)

    Itooka, Satoshi; Saito, Yoshinori [Hitachi Ltd., Nuclear Systems Division, Hitachi, Ibaraki (Japan); Okabe, Ayao; Fujimata, Kazuhiro; Murata, Shuuichi [Hitachi Engineering Co., Ltd., Nuclear Power Plant Engineering No.2 Dept., Hitachi, Ibaraki (Japan)

    2000-03-01

    In selecting the reasonable DBL on steam generator (SG), it is necessary to improve analytical method for estimating the sodium temperature on failure propagation due to overheating. Improvement on sodium-water reaction (SWR) jet code (LEAP-JET ver.1.30) and application analysis to the water injection tests for confirmation of code propriety were performed. On the improvement of the code, a gas-liquid interface area density model was introduced to develop a chemical reaction model with a little dependence on calculation mesh size. The test calculation using the improved code (LEAP-JET ver.1.40) were carried out with conditions of the SWAT-3{center_dot}Run-19 test and an actual scale SG. It is confirmed that the SWR jet behavior on the results and the influence to analysis result of a model are reasonable. For the application analysis to the water injection tests, water injection behavior and SWR jet behavior analyses on the new SWAT-1 (SWAT-1R) and SWAT-3 (SWAT-3R) tests were performed using the LEAP-BLOW code and the LEAP-JET code. In the application analysis of the LEAP-BLOW code, parameter survey study was performed. As the results, the condition of the injection nozzle diameter needed to simulate the water leak rate was confirmed. In the application analysis of the LEAP-JET code, temperature behavior of the SWR jet was investigated. (author)

  16. Computational analysis of the mechanism of chemical reactions in terms of reaction phases: hidden intermediates and hidden transition States.

    Science.gov (United States)

    Kraka, Elfi; Cremer, Dieter

    2010-05-18

    Computational approaches to understanding chemical reaction mechanisms generally begin by establishing the relative energies of the starting materials, transition state, and products, that is, the stationary points on the potential energy surface of the reaction complex. Examining the intervening species via the intrinsic reaction coordinate (IRC) offers further insight into the fate of the reactants by delineating, step-by-step, the energetics involved along the reaction path between the stationary states. For a detailed analysis of the mechanism and dynamics of a chemical reaction, the reaction path Hamiltonian (RPH) and the united reaction valley approach (URVA) are an efficient combination. The chemical conversion of the reaction complex is reflected by the changes in the reaction path direction t(s) and reaction path curvature k(s), both expressed as a function of the path length s. This information can be used to partition the reaction path, and by this the reaction mechanism, of a chemical reaction into reaction phases describing chemically relevant changes of the reaction complex: (i) a contact phase characterized by van der Waals interactions, (ii) a preparation phase, in which the reactants prepare for the chemical processes, (iii) one or more transition state phases, in which the chemical processes of bond cleavage and bond formation take place, (iv) a product adjustment phase, and (v) a separation phase. In this Account, we examine mechanistic analysis with URVA in detail, focusing on recent theoretical insights (with a variety of reaction types) from our laboratories. Through the utilization of the concept of localized adiabatic vibrational modes that are associated with the internal coordinates, q(n)(s), of the reaction complex, the chemical character of each reaction phase can be identified via the adiabatic curvature coupling coefficients, A(n,s)(s). These quantities reveal whether a local adiabatic vibrational mode supports (A(n,s) > 0) or resists

  17. New data and evaluation of sup 3 He-induced nuclear reactions on Cu

    CERN Document Server

    Tarkanyi, F; Takács, S; Al-Abyad, M; Mustafa, M G; Shubin, Y; Zhuang, Y

    2002-01-01

    Excitation functions of sup n sup a sup t Cu( sup 3 He, x) sup 6 sup 6 Ga, sup n sup a sup t Cu( sup 3 He, x) sup 6 sup 7 Ga, sup n sup a sup t Cu( sup 3 He, x) sup 6 sup 3 Zn and sup n sup a sup t Cu( sup 3 He, x) sup 6 sup 5 Zn nuclear reactions were measured up to 36 MeV using stacked foil irradiation arrangement and activation technique. The results were compared with compiled literature data. The status of the experimental database was investigated with the goal to produce recommended values for different applications. The application of the deduced data in the field of beam monitoring and thin layer activation is discussed.

  18. Measurement and evaluation of the excitation functions for alpha particle induced nuclear reactions on niobium

    CERN Document Server

    Tarkanyi, F; Szelecsenyi, F; Sonck, M; Hermanne, A

    2002-01-01

    Alpha particle induced nuclear reactions were investigated with the stacked foil activation technique on natural niobium targets up to 43 MeV. Excitation functions were measured for the production of sup 9 sup 6 sup m sup g Tc, sup 9 sup 5 sup m Tc, sup 9 sup 5 sup g Tc, sup 9 sup 4 sup g Tc, sup 9 sup 5 sup m sup g Nb and sup 9 sup 2 sup m Nb. Cumulative cross-sections, thick target yields and activation functions were deduced and compared with available literature data. Applications of the excitation functions in the field of thin layer activation techniques and beam monitoring are also discussed.

  19. Arrangement for remote automatic change of recording angle nuclear reaction products

    International Nuclear Information System (INIS)

    The arrangement intended for remote automatic angular displacement of detectors at measurement of angular distributions of nuclear reaction products is described. The arrangement provides a remote switching in and switching out of motor with a reversal possibility as well as a turning angle value count. Due to the fact that the motor control is realized by logical levels t.t.l. and the angle count is performed by a logical pulse number, the arrangement makes it possible to rather simply introduce semiautomatic or automatic (for example, by means of a computer) control of the angle change. The arrangement consists of a mechanical drive, convertor, ''turning angle-code'' and an engine remote control scheme. Owing to the absence of mechanically switching contacts the arrangement being relative simple possesses higher reliability

  20. Proceedings of the 2nd joint seminar on atomic collisions and heavy ion induced nuclear reactions

    International Nuclear Information System (INIS)

    The meeting of the 2nd joint seminar on atomic collisions and heavy ion induced nuclear reactions was held at the University of Tokyo, May 13 and 14, 1982. The aim of this seminar has been not only to recognize the common problems lying between above two research fields, but also to obtain an overview of the theoretical and experimental approaches to clear the current problems. In the seminar, more than 50 participants gathered and presented 16 papers. These are two general reviews and fourteen comprehensive surveys on topical subjects which have been developed very intensively in recent years. The editors would like to thank all participants for their assistance and cooperation in making possible a publication of these proceedings. (author)

  1. Information theory and statistical nuclear reactions. I. General theory and applications to few-channel problems

    Energy Technology Data Exchange (ETDEWEB)

    Mello, P.A.; Pereyra, P.; Seligman, T.H.

    1985-05-01

    Ensembles of scattering S-matrices have been used in the past to describe the statistical fluctuations exhibited by many nuclear-reaction cross sections as a function of energy. In recent years, there have been attempts to construct these ensembles explicitly in terms of S, by directly proposinng a statistical law for S. In the present paper, it is shown that, for an arbitrary number of channels, one can incorporate, in the ensemble of S-matrices, the conditions of flux conservation, time-reversal invariance, causality, ergodicity, and the requirement that the ensemble average coincide with the optical scattering matrix. Since these conditions do not specify the ensemble uniquely, the ensemble that has maximum information-entropy is dealt with among those that satisfy the above requirements. Some applications to few-channel problems and comparisons to Monte-Carlo calculations are presented.

  2. CO2 laser experiments using nuclear reactions as the ionization source.

    Science.gov (United States)

    Rhoads, H. S.; Schneider, R. T.; Allario, F.

    1971-01-01

    Experimental studies show that the output of a CO2 laser is significantly increased by products of the nuclear reaction He-3 (n,p)T. Helium-3 was used in lieu of the natural helium normally present in the 1:1:8 CO2:N2:He laser gas mixture (pressure = 6 torr). The laser assembly was then exposed to a reactor thermal neutron flux of about 100 million neutrons/sq cm/sec. Power output of the laser doubled while the electrical power input decreased; electrical efficiency was thus more than doubled. Results indicate that additional ionization by the energetic charged particles may be responsible for the improved laser performance.

  3. Feasibility study of nuclear transmutation by negative muon capture reaction using the PHITS code

    Science.gov (United States)

    Abe, Shin-ichiro; Sato, Tatsuhiko

    2016-06-01

    Feasibility of nuclear transmutation of fission products in high-level radioactive waste by negative muon capture reaction is investigated using the Particle and Heave Ion Transport code System (PHITS). It is found that about 80 % of stopped negative muons contribute to transmute target nuclide into stable or short-lived nuclide in the case of 135Cs, which is one of the most important nuclide in the transmutation. The simulation result also indicates that the position of transmutation is controllable by changing the energy of incident negative muon. Based on our simulation, it takes approximately 8.5 × 108years to transmute 500 g of 135Cs by negative muon beam with the highest intensity currently available.

  4. Harmonic oscillator representation in the theory of scattering and nuclear reactions

    Science.gov (United States)

    Smirnov, Yuri F.; Shirokov, A. M.; Lurie, Yuri, A.; Zaitsev, S. A.

    1995-01-01

    The following questions, concerning the application of the harmonic oscillator representation (HOR) in the theory of scattering and reactions, are discussed: the formulation of the scattering theory in HOR; exact solutions of the free motion Schroedinger equation in HOR; separable expansion of the short range potentials and the calculation of the phase shifts; 'isolated states' as generalization of the Wigner-von Neumann bound states embedded in continuum; a nuclear coupled channel problem in HOR; and the description of true three body scattering in HOR. As an illustration the soft dipole mode in the (11)Li nucleus is considered in a frame of the (9)Li+n+n cluster model taking into account of three body continuum effects.

  5. Cyclotron production of I-123: An evaluation of the nuclear reactions which produce this isotope

    Science.gov (United States)

    Sodd, V. J.; Scholz, K. L.; Blue, J. W.; Wellman, H. N.

    1970-01-01

    The use of the various nuclear reactions is described by which I-123,a low radiation dose radiopharmaceutical, can be cyclotron-produced. Methods of directly producing I-123 and those which indirectly produce the radionuclide through the beta (+) decay of its nautral precursor, Xe-123. It is impossible to separate from the radioiodine contaminants, notably I-124, which occur in the direct method. Thus, it is preferable to produce pure I-123 from Xe-123 which is easily separated from the radioiodines. Among the characteristics of I-123 is the capability of reducing the patient dose in a thyroid uptake measurement to a very small percentage of that delivered by the more commonly used I-131.

  6. Investigation of phosphorous in thin films using the 31P(α,p)34S nuclear reaction

    Science.gov (United States)

    Pitthan, E.; Gobbi, A. L.; Stedile, F. C.

    2016-03-01

    Phosphorus detection and quantification were obtained, using the 31P(α,p)34S nuclear reaction and Rutherford Backscattering Spectrometry, in deposited silicon oxide films containing phosphorus and in carbon substrates implanted with phosphorus. It was possible to determine the total amount of phosphorus using the resonance at 3.640 MeV of the 31P(α,p)34S nuclear reaction in samples with phosphorus present in up to 23 nm depth. Phosphorous amounts as low as 4 × 1014 cm-2 were detected. Results obtained by nuclear reaction were in good agreement with those from RBS measurements. Possible applications of phosphorus deposition routes used in this work are discussed.

  7. Propagation of nuclear data Uncertainties for PWR core analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cabellos, O.; Castro, E.; Ahnert, C.; Holgado, C. [Dept. of Nuclear Engineering, Universidad Politecnica de Madrid, Madrid (Spain)

    2014-06-15

    An uncertainty propagation methodology based on the Monte Carlo method is applied to PWR nuclear design analysis to assess the impact of nuclear data uncertainties. The importance of the nuclear data uncertainties for {sup 235,238}U, {sup 239}Pu, and the thermal scattering library for hydrogen in water is analyzed. This uncertainty analysis is compared with the design and acceptance criteria to assure the adequacy of bounding estimates in safety margins.

  8. Can nuclear energy support civilized society in the 21st century? From a civilization based on chemical reactions to a civilization based on nuclear reactions

    International Nuclear Information System (INIS)

    The United Nations passed and adopted 'Principles of Sustainable Development' in 1992, as a resolution on the sustainable development of mankind. It advocates maintaining the ecological system to support the earth, while presenting the ethical issue of 'impartiality within a generation', the reduction of absolute poverty and also 'impartiality between generations', in particular 'not leaving a negative legacy to the next generation'. The issue of the appropriate handling of waste is by nature an issue of safety and resources, but is also an ethical issue. Nuclear power generation is more likely to conserve the environment, if the comparison between radioactive waste and carbon dioxide is considered. The creation of hydrogen by nuclear energy resembles the ecological relationship between the sun and the earth in that it consists of the conversion of nuclear energy into chemical energy. Nuclear fission, nuclear fusion, particle acceleration and lasers can all be found in the universe. It will be possible to find a future for nuclear energy by learning from and imitating nature. If the future of nuclear energy is seen from the viewpoint of sustainability, it can be expected that energy resources will be secured and the environment will be conserved by a system of nuclear energy, which will hopefully grow into a comprehensive nuclear science and technology that supports the civilization at its roots. (orig.)

  9. Exclusive CHIPS-TPT algorithms for simulation of neutron-nuclear reactions

    Science.gov (United States)

    Kosov, Mikhail; Savin, Dmitriy

    2016-09-01

    The CHIPS-TPT physics library for simulation of neutron-nuclear reactions on the new exclusive level is being developed in CFAR VNIIA. The exclusive modeling conserves energy, momentum and quantum numbers in each neutron-nuclear interaction. The CHIPS-TPT algorithms are based on the exclusive CHIPS library, which is compatible with Geant4. Special CHIPS-TPT physics lists in the Geant4 format are provided. The calculation time for an exclusive CHIPS-TPT simulation is comparable to the time of the corresponding inclusive Geant4-HP simulation and much faster for mono-isotopic simulations. In addition to the reduction of the deposited energy fluctuations, which is a consequence of the energy conservation, the CHIPS-TPT libraries provide a possibility of simulation of the secondary particles correlation, e.g. secondary gammas or n-γ correlations, and of the Doppler broadening of the γ-lines in the simulated spectra, which can be measured by germanium detectors.

  10. Neutron-enhanced annealing of ion-implantation induced damage in silicon heated by nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Kinomura, A., E-mail: a.kinomura@aist.go.jp [National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Yoshiie, T. [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Chayahara, A.; Mokuno, Y.; Tsubouchi, N.; Horino, Y. [National Institute of Advanced Industrial Science and Technology (AIST), AIST Kansai, 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Xu, Q.; Sato, K. [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Yasuda, K.; Ishigami, R. [The Wakasa Wan Energy Research Center, 64-52-1 Nagatani, Tsuruga, Fukui 914-0192 (Japan)

    2014-09-01

    Highlights: •Neutron-enhanced annealing was observed for irradiation damage in Si below 90 °C. •The irradiation was performed in a nuclear reactor without intentional heating. •Reduction of damage peaks was detected by Rutherford backscattering/channeling. •The annealing efficiency was comparable to that of ion-beam annealing. -- Abstract: The effect of neutron irradiation on recovery (annealing) of irradiation damage has been investigated for self-ion implanted Si. A damage layer was introduced by 200 keV Si{sup +} implantation to a fluence of 5 × 10{sup 14} Si/cm{sup 2} at room temperature. The damaged samples were neutron-irradiated to 3.8 × 10{sup 19} n/cm{sup 2} (fast neutron), without intentional heating, in the core of the Kyoto University Reactor. During neutron irradiation, the samples were heated only by nuclear reactions, and the irradiation temperature was estimated to be less than 90 °C. The damage levels of the samples were characterized by Rutherford backscattering with channeling. Reduction of damage peaks as a result of neutron irradiation was clearly observed in the samples. The annealing efficiency was calculated to be 0.44 defects/displacement.

  11. Effects of isospin dynamics on neck fragmentation in isotopic nuclear reactions

    Science.gov (United States)

    Feng, Zhao-Qing

    2016-07-01

    The neck dynamics in Fermi-energy heavy-ion collisions, to probe the nuclear symmetry energy in the domain of subsaturation densities, is investigated within an isospin-dependent transport model. The single and double ratios of neutrons to protons from free nucleons and light clusters (complex particles) in the isotopic reactions are analyzed systematically. Isospin effects of particles produced from the neck fragmentations are explored. It is found that the ratios of the energetic isospin particles strongly depend on the stiffness of the nuclear symmetry energy and the effects increase with softening of the symmetry energy, which would be a nice probe for extracting the symmetry energy below the normal density in experiments. A flat structure appears at the tail spectra from the double ratio distributions. The neutron to proton ratio of light intermediate-mass fragments with charge number Z ≤8 is related to the density dependence of the symmetry energy with less sensitivity in comparison to the isospin ratios of nucleons and light particles.

  12. Some parameters of uranium hexafluoride plasma produced by products of nuclear reaction

    International Nuclear Information System (INIS)

    The probe experimental results of investigation of uranium hexafluoride plasma produced in the centre of nuclear reactor core were demonstrated. Study of uranium hexafluoride plasma is continued by the following reasons: a possibility of U F6 utilization as nuclear fuel, the utilization of U F6 as volume source o ionization, search of active laser media compatible with U F6 that is complicated by lack of constant rates data for most of plasma-chemical reactions with U F6 and his dissociation products. Cylindrical probe volt-ampere characteristics (VAC) measured in U F6 plasma at pressure 20 Torr and different thermal neutron fluxes and have following features: -firstly, it is possible to choose a linear part in the field of small positive potentials of probe (0-1) V; - secondary, ion branches of VAC have typical break which current of satiation corresponds to; -thirdly, probe VAC measured at small values of thermal neutron flux density are symmetrical. Diagnostics approaches were used for interpretation VAC of probe. The values of satiation current and linear part of electron branch were calculated, and such plasma parameters as conductivity, diffusion coefficient values of positive and negative ions were determined. The resonance recharge cross section was estimated on diffusion coefficient value

  13. Report on the consultants' meeting on co-ordination of the nuclear reaction data centres. (Technical aspects)

    International Nuclear Information System (INIS)

    This report summarizes the 1999 Co-ordination Meeting on Technical Aspects of the Co-operation of the Nuclear Reaction Data Centres, hold at the IAEA Headquarters in Vienna, Austria, 18 to 20 May 1999. The meeting was attended by scientists from 11 Nuclear Data Centres from 7 Member States and 2 International Organizations. The present document contains a meeting summary, the conclusions and actions, and progress reports of the Participating Data Centres. (author)

  14. Uncertainty evaluation of nuclear reaction model parameters using integral and microscopic measurements. Covariances evaluation with CONRAD code

    Directory of Open Access Journals (Sweden)

    Tommasi J.

    2010-10-01

    Full Text Available In the [eV;MeV] energy range, modelling of the neutron induced reactions are based on nuclear reaction models having parameters. Estimation of co-variances on cross sections or on nuclear reaction model parameters is a recurrent puzzle in nuclear data evaluation. Major breakthroughs were asked by nuclear reactor physicists to assess proper uncertainties to be used in applications. In this paper, mathematical methods developped in the CONRAD code[2] will be presented to explain the treatment of all type of uncertainties, including experimental ones (statistical and systematic and propagate them to nuclear reaction model parameters or cross sections. Marginalization procedure will thus be exposed using analytical or Monte-Carlo solutions. Furthermore, one major drawback found by reactor physicist is the fact that integral or analytical experiments (reactor mock-up or simple integral experiment, e.g. ICSBEP, … were not taken into account sufficiently soon in the evaluation process to remove discrepancies. In this paper, we will describe a mathematical framework to take into account properly this kind of information.

  15. A systems analysis approach to nuclear facility siting

    International Nuclear Information System (INIS)

    An attempt is made to demonstrate an application of the techniques of systems analysis, which have been successful in solving a variety of problems, to nuclear facility siting. Within the framework of an overall regional land-use plan, a methodology for establishing the acceptability of a combination of site and facility is discussed. The consequences (e.g. the energy produced, thermal and chemical discharges, radioactive releases, aeshetic values, etc.) of the site-facility combination are identified and compared with formalized criteria in order to ensure 'legal acceptability'. Failure of any consequences to satisfy standard requirements results in a feedback channel which works to effect design changes in the facility. When 'legal acceptability' has been assured, the project enters the public sector for consideration. The responses of individuals and of various interested groups to the external attributes of the nuclear facility gradually emerge. The criteria by which interest groups judge technological advances reflect both their rational assessment and unconscious motivations. This process operates on individual, group, societal and international levels and may result in two basic feedback loops: one which might act to change regulatory criteria; the other which might influence facility design or site selection. Such reactions and responses on these levels result in a continuing process of confrontation, collaborative interchange and possible resolution in the direction of an acceptable solution. Finally, a Paretian approach to optimizing the site-facility combination is presented for the case where there are several possible combinations of site and facility. A hypothetical example of the latter is given, based upon typical preference functions determined for four interest groups. The research effort of the IIASA Energy Systems Project and the Joint IAEA/IIASA Research Project in the area of nuclear siting is summarized. (author)

  16. Strong screening effects on resonant nuclear reaction $^{23}$Mg $(p,\\gamma)$ $^{24}$Al in the surface of magnetars

    CERN Document Server

    Liu, Jing-Jing

    2016-01-01

    Based on the theory of relativistic superstrong magnetic fields(SMFs), by using the method of the Thomas-Fermi-Dirac approximations, we investigate the problem of strong electron screening(SES) in SMFs, and the influence of SES on the nuclear reaction of $^{23}$Mg $(p, \\gamma)$$^{24}$Al. Our calculations show that the nuclear reaction will be markedly effected by the SES in SMFs in the surface of magnetars. Our calculated screening rates can increase two orders of magnitude due to SES in SMFs.

  17. EXITATION OF ELECTROMAGNETIC RADIATION, NUCLEAR REACTION AND PARTICLES DECAY BY THE ACCELERATION

    Directory of Open Access Journals (Sweden)

    Trunev A. P.

    2015-05-01

    Full Text Available The article discusses the excitation of electromagnetic radiation, nuclear reactions and decays of particles by the acceleration of charges, atomic nuclei and the macroscopic volumes of matter. The motion of charged particles in a magnetic trap used for plasma confinement was computed. We propose a model of the electromagnetic radiation of a charge moving in a non-inertial reference frame in general relativity. We have also constructed a theory of perturbation with using a wave equation with small parameters, taking into account a characteristic radius of the trajectory of the electrons as they move in a magnetic field. It was found that in the first approximation, the radiation back-reaction force depends on the acceleration of the charge. For the simulating of processes in hadrons and nuclei we used Yang-Mills theory and the metric, describes the acceleration and rotating reference frame in general relativity. We consider the scalar glueball model for an arbitrary dependence of acceleration and angular velocity of the system on time. The numerical model of wave propagation in non-inertial reference frame for the geometry of system of one, two or three spatial dimensions was tested. In the numerical experiments shown that the acceleration of the system leads to instability, leading to an unlimited increase in the amplitude of waves, which is interpreted as a decay of system. It was found that there are critical values of acceleration above which the instability develops

  18. Nuclear structure and reaction studies with exotic nuclei at the FRS-ESR

    International Nuclear Information System (INIS)

    Nuclear physics with exotic nuclei in storage rings was pioneered at the SIS-ESR facility in combination with the fragment separator FRS. Already the first experiments in the early 1990's gave access to ground-state properties like masses and half-lives and indicated the research potential of this novel instrumental approach. Many new data have been obtained and interesting phenomena have been explored, e.g. the mass surface was mapped over large areas of the chart of nuclei, isomer studies of long-lived states (with half-lives of the order minutes) became possible, the modification of decay properties for highly-charged, high-Z exotic nuclei was observed, and new decay modes, like the beta-decay to bound final states, were studied for the first time. A few years ago, direct reaction experiments on internal targets using inverse kinematics were started: transfer and pickup reactions of astrophysical interest were performed with stable isotopes at energies approaching the Gamow-window, while elastic and inelastic scattering experiments were performed with secondary beams of the unstable doubly magic isotope 56Ni quite recently. In this contribution, the achievements will be reviewed and recent results will be presented. It is dedicated to Paul Kienle. (authors)

  19. Microbial catalysis of redox reactions in concrete cells of nuclear waste repositories: a review and introduction

    International Nuclear Information System (INIS)

    In this paper, we will review the importance of oxy anions in the nuclear industry; their impact together with concrete, steel and organic matter on the redox state in the near field of a waste storage. Particular consideration will be given to the knowledge in relation to alcaliphilic microbial activity in some cases derived from existing natural analogues. Case studies will consider specific redox-sensitive radionuclides in both near surface and deep storage settings. This information will serve as input to two ongoing experimental endeavour dealing with the specific reaction of nitrate reduction by organic matter and/or H2 in the concrete cells for bituminous waste disposal. It is not possible to predict the evolution in space and time of the various microbial species capable of influencing key processes occurring in concrete-dominated repository systems. It is thus not really possible to predict reaction kinetics controlled by microbial activity. Two approaches are none-the-less useful; a biogeochemical simulation exercise will help tracing the reactionary paths and a mass balance approach reducing uncertainties in regard to the final, possibly equilibrium situation. Both are described here with the goal in mind to syntheses and conclude a subject matter which is at full scientific swing

  20. Nuclear structure and reaction studies with exotic nuclei at the FRS-ESR

    Directory of Open Access Journals (Sweden)

    Scheidenberger Christoph

    2014-03-01

    Full Text Available Nuclear physics with exotic nuclei in storage rings was pioneered at the SIS-ESR facility in combination with the fragment separator FRS. Already the first experiments in the early 1990s gave access to ground-state properties like masses and half-lives and indicated the research potential of this novel instrumental approach. Many new data have been obtained and interesting phenomena have been explored, e.g. the mass surface was mapped over large areas of the chart of nuclei, isomer studies of long-lived states (with half-lives of the order minutes became possible, the modification of decay properties for highly-charged, high-Z exotic nuclei was observed, and new decay modes, like the beta-decay to bound final states, were studied for the first time. A few years ago, direct reaction experiments on internal targets using inverse kinematics were started: transfer and pickup reactions of astrophysical interest were performed with stable isotopes at energies approaching the Gamow-window, while elastic and inelastic scattering experiments were performed with secondary beams of the unstable doubly magic isotope 56Ni quite recently. In this contribution, the achievements will be reviewed and recent results will be presented. It is dedicated to Paul Kienle.