WorldWideScience

Sample records for alpha-induced nuclear reactions

  1. Subthreshold K+ production in deuteron and alpha induced nuclear reactions

    CERN Document Server

    Debowski, M; Boivin, M; Le Bornec, Y; Courtat, P; Gacougnolle, R; Grosse, E; Kabana, S; Kirchner, T; Koczón, P; Mang, M; Schwab, E; Tatischeff, B; Wagner, A; Walús, W; Willis, N; Wolf, G; Wurzinger, R; Yonnet, J

    1997-01-01

    Double differential cross sections have been measured for pi+ and K+ emitted around midraidity in d+A and He+A collisions at a beam kinetic energy of 1.15 GeV/nucleon. The total pi+ yield increases by a factor of about 2 when using an alpha projectile instead of a deuteron whereas the K+ yield increases by a factor of about 4. According to transport calculations, the K+ enhancement depends both on the number of hadron-hadron collisions and on the energy available in those collisions: their center-of-mass energy increases with increasing number of projectile nucleons.

  2. Cross sections of $\\alpha$-induced reactions for targets with masses $A \\approx 20-50$ at low energies

    CERN Document Server

    Mohr, Peter

    2015-01-01

    A simple reduction scheme using so-called reduced energies $E_{\\rm{red}}$ and reduced cross sections $\\sigma_{\\rm{red}}$ allows the comparison of heavy-ion induced reaction cross sections for a broad range of masses of projectile and target and over a wide energy range. A global behavior has been found for strongly bound projectiles whereas much larger reduced cross sections have been observed for weakly bound and halo projectiles. It has been shown that this simple reduction scheme works also well for $\\alpha$-particle induced reactions on heavy target nuclei, but very recently significant deviations have been seen for $\\alpha$+$^{33}$S and $\\alpha$+$^{23}$Na. Motivated by these unexpected discrepancies, the present study analyses $\\alpha$-induced reaction cross sections for targets with masses $A \\approx 20-50$. The study shows that the experimental data for $\\alpha$-induced reactions on nuclei with $A \\approx 20-50$ deviate slightly from the global behavior of reduced cross sections. However, in general th...

  3. $\\mathbf{\\alpha}$-induced reaction cross sections in the mass range $\\mathbf{A \\approx 20 - 50}$: a critical review

    CERN Document Server

    Mohr, Peter

    2016-01-01

    In a recent review it was shown that the cross sections of $\\alpha$-induced reactions in the $A \\approx 20 - 50$ mass range follow a general and smooth trend in most cases. For comparison of cross sections of different targets at various energies the method of reduced cross sections $\\sigma_{\\rm{red}}$ and reduced energies $E_{\\rm{red}}$ was used. Four outliers were identified: $^{36}$Ar and $^{40}$Ar with unusally small cross sections and $^{23}$Na and $^{33}$S with unusually large cross sections. New data for $^{23}$Na were presented at this NPA-7 conference; contrary to the previous data, these new data fit into the general systematics. In addition, a relation between the most effective energy $E_0$ for astrophysical reaction rates (the so-called Gamow window) and the reduced energy $E_{\\rm{red}}$ is presented.

  4. Alpha induced reaction cross section measurements on 162Er for the astrophysical gamma process

    CERN Document Server

    Kiss, G G; Rauscher, T; Török, Zs; Fülöp, Zs; Gyürky, Gy; Halász, Z; Somorjai, E

    2014-01-01

    The cross sections of the 162Er(a,g,)166Yb and 162Er(a,n)165Yb reactions have been measured for the first time. The radiative alpha capture reaction cross section was measured from Ec.m. = 16.09 down to Ec.m. = 11.21 MeV, close to the astrophysically relevant region (which lies between 7.8 and 11.48 MeV at 3 GK stellar temperature). The 162Er(a,n)165Yb reaction was studied above the reaction threshold between Ec.m. = 12.19 and 16.09 MeV. The fact that the 162Er(a,g)166Yb cross sections were measured below the (a,n) threshold at first time in this mass region opens the opportunity to study directly the a-widths required for the determination of astrophysical reaction rates. The data clearly show that compound nucleus formation in this reaction proceeds differently than previously predicted.

  5. Measurement of alpha-induced reaction cross sections on erbium isotopes for γ process studies

    Science.gov (United States)

    Kiss, G. G.; Szücs, T.; Török, Zs.; Fülöp, Zs.; Gyürky, Gy.; Halász, Z.; Somorjai, E.; Rauscher, T.

    2014-05-01

    The cross sections of the 162Er(α,γ)166Yb and 162,164,166Er(α,n)165,167,169Yb reactions have been measured at MTA Atomki. The radiative alpha capture reaction cross section was measured between Ec.m. = 11.21 MeV and Ec.m. = 16.09 MeV just above the astrophysically relevant energy region (which lies between 7.8 and 11.48 MeV at T9 = 3 GK). The 162Er(α,n)165Yb, 164Er(α,n)167Yb and 166Er(α,n)169Yb reactions were studied between Ec.m. = 12.19 and 16.09 MeV, Ec.m. = 13.17 and 16.59 MeV and Ec.m. = 12.68 and 17.08 MeV, respectively. The aim of this work is to provide experimental data for modeling the γ process which is thought to be responsible for the production of the proton-rich isotopes heavier than iron.

  6. 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.

  7. Test of statistical model cross section calculations for $\\alpha$-induced reactions on $^{107}$Ag at energies of astrophysical interest

    CERN Document Server

    Yalcin, C; Rauscher, T; Kiss, G G; Özkan, N; Güray, R T; Halász, Z; Szücs, T; Fülöp, Zs; Korkulu, Z; Somorjai, E

    2015-01-01

    Astrophysical reaction rates, which are mostly derived from theoretical cross sections, are necessary input to nuclear reaction network simulations for studying the origin of $p$ nuclei. Past experiments have found a considerable difference between theoretical and experimental cross sections in some cases, especially for ($\\alpha$,$\\gamma$) reactions at low energy. Therefore, it is important to experimentally test theoretical cross section predictions at low, astrophysically relevant energies. The aim is to measure reaction cross sections of $^{107}$Ag($\\alpha$,$\\gamma$)$^{111}$In and $^{107}$Ag($\\alpha$,n)$^{110}$In at low energies in order to extend the experimental database for astrophysical reactions involving $\\alpha$ particles towards lower mass numbers. Reaction rate predictions are very sensitive to the optical model parameters and this introduces a large uncertainty into theoretical rates involving $\\alpha$ particles at low energy. We have also used Hauser-Feshbach statistical model calculations to s...

  8. 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...

  9. 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.

  10. 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...

  11. 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 ...

  12. 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.

  13. 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.

  14. 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)

  15. 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.

  16. 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

  17. 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 ...

  18. 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.

  19. 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)

  20. 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.

  1. Nuclear gamma rays from 720-MeV alpha-induced reactions on Al-27 and Si-28

    Science.gov (United States)

    Lieb, B. J.; Plendl, H. S.; Funsten, H. O.; Stronach, C. E.; Lind, V. G.

    1980-01-01

    Prompt gamma rays from the interaction of 720-MeV alpha particles with Al-27 and Si-28 were detected and analyzed to identify residual nuclei and to determine cross sections for production of specific levels. No gamma-ray transitions were detected from nuclei heavier than the target. From Doppler broadening, the momentum of the residual nuclei was estimated. The results are compared with previous results for 140- and 1600-MeV alphas on Al-27 and approximately 200-MeV positive or negative pions on Al-27 and Si-28 and fitted to a spallation-yield formula.

  2. Novel approaches to the analysis of nuclear and other radioactive materials - Improving detection capability through alpha-gamma coincidence, alpha-induced optical fluorescence and advanced spectrum analysis

    OpenAIRE

    Ihantola, Sakari

    2013-01-01

    Nuclear and other radioactive materials pose a special concern in the proliferation of nuclear weapons, reactor accidents or through criminal acts. To prevent the adverse effects of the use of these materials, novel approaches for their detection and analysis are required. The objective of the research in this thesis was to improve the detection and characterisation of nuclear and other radioactive materials with radiometric methods. Radioactive sources can be detected and identified base...

  3. 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...

  4. 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.

  5. 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)

  6. Mulberry leaf aqueous fractions inhibit TNF-alpha-induced nuclear factor kappaB (NF-kappaB) activation and lectin-like oxidized LDL receptor-1 (LOX-1) expression in vascular endothelial cells.

    Science.gov (United States)

    Shibata, Yusuke; Kume, Noriaki; Arai, Hidenori; Hayashida, Kazutaka; Inui-Hayashida, Atsuko; Minami, Manabu; Mukai, Eri; Toyohara, Masako; Harauma, Akiko; Murayama, Toshinori; Kita, Toru; Hara, Saburo; Kamei, Kaeko; Yokode, Masayuki

    2007-07-01

    Mulberry (Morus Alba L., family Moraceae) leaf extracts have various biological effects including inhibition of oxidative modification of low-density lipoprotein (LDL), which is the major cause of atherosclerosis. Endothelial dysfunction elicited by oxidized LDL (Ox-LDL) has been implicated in atherogenesis. Lectin-like Ox-LDL receptor-1 (LOX-1), a cell-surface receptor for atherogenic Ox-LDL, appears to mediate Ox-LDL-induced inflammation, which may be crucial in atherogenesis. Previous studies revealed that expression of LOX-1 is highly inducible by proinflammatory stimuli, including tumor necrosis factor-alpha (TNF-alpha), lipopolysaccharide (LPS), and transforming growth factor-beta (TGF-beta). Therefore, we examined whether mulberry leaf aqueous fractions inhibit LOX-1 expression induced by proinflammatory stimuli. Pretreatment of cultured bovine aortic endothelial cells (BAECs) with mulberry leaf aqueous fractions inhibited TNF-alpha- and LPS-induced expression of LOX-1 at both protein and mRNA levels in a time- and concentration-dependent manner. In contrast, mulberry leaf aqueous fractions did not affect TGF-beta-induced LOX-1 expression. Furthermore, mulberry leaf aqueous fractions inhibited TNF-alpha-induced activation of nuclear factor-kappaB (NF-kappaB) and phosphorylation of inhibitory factor of NF-kappaB-alpha (IkappaB-alpha) in a time- and concentration-dependent fashion. Thus, mulberry leaf aqueous fractions suppress TNF-alpha- and LPS-induced LOX-1 gene expression, by inhibiting NF-kappaB activation.

  7. 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.)

  8. 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)

  9. 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.)

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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)

  15. 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

  16. 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

  17. The {alpha}-induced thick-target {gamma}-ray yield from light elements

    Energy Technology Data Exchange (ETDEWEB)

    Heaton, R.K. [Queen`s Univ., Kingston, ON (Canada). Dept. of Physics]|[Lawrence Berkeley Lab., CA (United States)

    1994-10-01

    The {alpha}-induced thick-target {gamma}-ray yield from light elements has been measured in the energy range 5.6 MeV {le} E{sub {alpha}} {le} 10 MeV. The {gamma}-ray yield for > 2.1 MeV from thick targets of beryllium, boron nitride, sodium fluoride, magnesium, aluminum and silicon were measured using the {alpha}-particle beam from the Lawrence Berkeley Laboratories 88 in. cyclotron. The elemental yields from this experiment were used to construct the {alpha}-induced direct production {gamma}-ray spectrum from materials in the SNO detector, a large volume ultra-low background neutrino detector located in the Creighton mine near Sudbury, Canada. This background source was an order of magnitude lower than predicted by previous calculations. These measurements are in good agreement with theoretical calculations of this spectrum based on a statistical nuclear model of the reaction, with the gross high energy spectrum structure being reproduced to within a factor of two. Detailed comparison of experimental and theoretical excitation population distribution of several residual nuclei indicate the same level of agreement within experimental uncertainties.

  18. 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...

  19. 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...

  20. 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)

  1. 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

  2. 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

  3. 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)

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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

  10. 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

  11. 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)

  12. 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)

  13. 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.

  14. 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…

  15. Omentin inhibits TNF-{alpha}-induced expression of adhesion molecules in endothelial cells via ERK/NF-{kappa}B pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Xia, E-mail: zhongxia1977@126.com [Department of Emergency, Provincial Hospital Affiliated to Shandong University, Jinan 250021 (China); Li, Xiaonan; Liu, Fuli; Tan, Hui [Department of Emergency, Provincial Hospital Affiliated to Shandong University, Jinan 250021 (China); Shang, Deya, E-mail: wenhuashenghuo1@163.com [Department of Emergency, Provincial Hospital Affiliated to Shandong University, Jinan 250021 (China)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Omentin inhibited TNF-{alpha}-induced adhesion of THP-1 cells to HUVECs. Black-Right-Pointing-Pointer Omentin reduces expression of ICAM-1 and VCAM-1 induced by TNF-{alpha} in HUVECs. Black-Right-Pointing-Pointer Omentin inhibits TNF-{alpha}-induced ERK and NF-{kappa}B activation in HUVECs. Black-Right-Pointing-Pointer Omentin supreeses TNF-{alpha}-induced expression of ICAM-1 and VCAM-1 via ERK/NF-{kappa}B pathway. -- Abstract: In the present study, we investigated whether omentin affected the expression of intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in tumor necrosis factor-{alpha} (TNF-{alpha}) induced human umbilical vein endothelial cells (HUVECs). Our data showed that omentin decreased TNF-{alpha}-induced expression of ICAM-1 and VCAM-1 in HUVECs. In addition, omentin inhibited TNF-{alpha}-induced adhesion of THP-1 cells to HUVECs. Further, we found that omentin inhibited TNF-{alpha}-activated signal pathway of nuclear factor-{kappa}B (NF-{kappa}B) by preventing NF-{kappa}B inhibitory protein (I{kappa}B{alpha}) degradation and NF-{kappa}B/DNA binding activity. Omentin pretreatment significantly inhibited TNF-{alpha}-induced ERK activity and ERK phosphorylation in HUVECs. Pretreatment with PD98059 suppressed TNF-{alpha}-induced NF-{kappa}B activity. Omentin, NF-kB inhibitor (BAY11-7082) and ERK inhibitor (PD98059) reduced the up-regulation of ICAM-1 and VCAM-1 induced by TNF-{alpha}. These results suggest that omentin may inhibit TNF-{alpha}-induced expression of adhesion molecules in endothelial cells via blocking ERK/NF-{kappa}B pathway.

  16. 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...

  17. 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.

  18. 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.

  19. 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.

  20. $^{12}$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.

  1. 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.

  2. 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

  3. 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...

  4. [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)

  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. 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.

  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. 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.

  9. 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...

  10. 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...

  11. 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

  12. 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) .

  13. 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)

  14. Cross section measurement of alpha particle induced nuclear reactions on natural cadmium up to 52 MeV

    CERN Document Server

    Ditrói, F; Haba, H; Komori, Y; Aikawa, M

    2016-01-01

    Cross sections of alpha particle induced nuclear reactions have been measured on thin natural cadmium targets foils in the energy range from 11 to 51.2 MeV. This work was a part of our systematic study on excitation functions of light ion induced nuclear reactions on different target materials. Regarding the cross sections, the alpha induced reactions are not deeply enough investigated. Some of the produced isotopes are of medical interest, others have application in research and industry. The radioisotope $^{117m}$Sn is a very important theranostic (therapeutic + diagnostic) radioisotope, so special care was taken to the results for that isotope. The well-established stacked foil technique followed by gamma-spectrometry with HPGe gamma spectrometers were used. The target and monitor foils in the stack were commercial high purity metal foils. From the irradiated targets $^{117m}$Sn, $^{113}$Sn, $^{110}$Sn, $^{117m,g}$In, $^{116m}$In, $^{115m}$In, $^{114m}$In, $^{113m}$In, $^{111}$In, $^{110m,g}$In, $^{109m}$I...

  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. 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.

  1. 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)

  2. 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.

  3. 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...

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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...

  11. 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

  12. 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.

  13. 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 ...

  14. 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.

  15. Direct Evidence of Washing out of Nuclear Shell Effects

    CERN Document Server

    Chaudhuri, A; Banerjee, K; Bhattacharya, S; Sadhukhan, Jhilam; Bhattacharya, C; Kundu, S; Meena, J K; Mukherjee, G; Pandey, R; Rana, T K; Roy, P; Roy, T; Srivastava, V; Bhattacharya, P

    2015-01-01

    Constraining excitation energy at which nuclear shell effect washes out has important implications on the production of super heavy elements and many other fields of nuclear physics research. We report the fission fragment mass distribution in alpha induced reaction on an actinide target for wide excitation range in close energy interval and show direct evidence that nuclear shell effect washes out at excitation energy ~40 MeV. Calculation shows that second peak of the ?fission barrier also vanishes around similar excitation energy.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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...

  3. 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

  4. 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.

  5. 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

  6. 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 ...

  7. 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.

  8. 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.

  9. 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...

  10. 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.

  11. 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.

  12. 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)

  13. 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)

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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...

  1. 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

  2. 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.

  3. 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.

  4. 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…

  5. 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…

  6. 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)

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.)

  14. 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.

  15. 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.

  16. 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.

  17. 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).

  18. 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.

  19. 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.

  20. 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.

  1. 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...

  2. 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...

  3. 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...

  4. 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.

  5. 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.

  6. 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...

  7. 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

  8. 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.

  9. Few-body nuclear reactions at low energies – an investigation on observed anomalies

    International Nuclear Information System (INIS)

    Few-body aspects of nuclear interaction are expected to be best studied at sufficiently lower energies where various pair-wise interactions overlap effectively with one another in the allowed phase space in kinematically complete configuration. In this direction, next to nucleon-deuteron systems, a very powerful testing ground has been the alpha-deuteron system where the alpha particle could be treated as a structureless boson due to its very high binding energy. The aim of the present work is to examine the strong anomalies observed in explaining the kinematically complete experimental observables in the light of Faddeev theoretical calculations (FT) due to Koike, involving alpha-induced break-up of deuterons at comparatively lower energies, ranging from Eα(inc)=11 to 18 MeV

  10. 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).

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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.)

  16. 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.)

  17. 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.

  18. 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.

  19. 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.

  20. 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.)

  1. 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

  2. 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)

  3. 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).

  4. 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...

  5. 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...

  6. 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 ...

  7. 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...

  8. 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

  9. 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.

  10. 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.

  11. 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)

  12. 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

  13. 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)

  14. 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

  15. 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...

  16. 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)

  17. 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.

  18. 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 ...

  19. 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.

  20. 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.)

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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)

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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)

  16. 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.

  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.

    2016-01-01

    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

  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.

    2016-04-01

    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.

  19. 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.

  20. 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.

  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. 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.

  3. 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.)

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. 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)

  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. 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.

  18. 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.)

  19. 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

  20. 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.

  1. 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

  2. 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)

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. 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)

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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%.

  8. 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).

  9. 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).

  10. 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.

  11. 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

  12. 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)

  13. 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.

  14. 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...

  15. 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)

  16. Hydrogen sulfide inhibits tumor necrosis factor alpha induced inflammatory response of keratinocytes via nuclear factor-kappa B pathway%硫化氢通过核因子-kappa B途径抑制肿瘤坏死因子alpha诱导的角质形成细胞的炎症反应

    Institute of Scientific and Technical Information of China (English)

    Ammar K H Ashorafa; 郭庆; 曾凡钦; 陈敏春; 谭国珍; 唐增奇; 尹若菲

    2011-01-01

    目的:探讨外源性硫化氢(Hydrogen sulfide,H2S)对肿瘤坏死因子alpha(Tumor necrosis factor alpha,TNF-α)诱导的角质形成细胞分泌炎症因子白细胞介素6 (Interleukin 6,IL-6)、白细胞介素8(Interleukin 8,IL-8)以及一氧化氮(Nitric oxide,NO)的影响,并探讨核转录因子kappa B(Nuclear factor kappa B,NF-κB)信号通路途径是否参与此过程.方法:应用TNF-α诱导HaCat细胞分泌炎症因子,以硫氢化钠(Sodium hydrosulfide,NaHS)作为H2S的供体,设置不同浓度的量效组.采用ELISA法测定HaCat细胞分泌IL-6和IL-8的水平,RT-PCR法检测HaCat细胞IL-6和IL-8的mRNA水平,Griess法检测HaCat细胞分泌NO水平,Western blot检测HaCat细胞胞内诱导型一氧化氮合酶(Inducible nitric oxide synthase,iNOS)、磷酸化I-kappa B-alpha(Phosphorylation of I-kappa B-alpha,p-IKB-α)和胞核内NF-κB P65水平.结果:10 ng/ml的TNF-α能显著诱导HaCat细胞内IL-6和IL-8因子的转录和分泌,培养上清NO产量和胞内iNOS含量明显增高,胞内p-IKB-α和胞核P65水平明显提高.在TNF-α诱导HaCat细胞前1h,给与20~400 μmol/L的NaHS做预处理,结果显示NaHS呈剂量依赖性地抑制HaCat细胞分泌IL-6、IL-8和NO,并能部分抑制NF-κB信号通路的活化.结论:H2S通过抑制NF-κB信号通路的活化来抑制TNF-α诱导角质形成细胞的炎症反应.%Objective:To investigate the effects of exogenous hydrogen sulfide(H2S) on the production of interleukin 6 (IL-6) ,inter-leukin 8(IL-8) ,and nitric oxide (NO) in keratinocytes induced by tumor necrosis factor alpha (TNF-α) ,and to explore whether nu-clear factor kappa B(NF-κB) signaling pathway is involved in this process. Methods: HaCat cells were induced by TNF-α to secrete inflammatory factors,and the H2S donor,sodium hydro-sulfide (NaHS),was added to the medium with different concentrations.The levels of IL-6 and IL-8 secreted by HaCat cells were measured by ELISA method ;RT-PCR was performed to detect IL-6 and IL-8

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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)

  2. 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

  3. 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

  4. 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.

  5. 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

  6. 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 ...

  7. 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

  8. 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...

  9. 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.

  10. 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.

  11. Temperature dependence of alpha-induced scintillation in the 1,1,4,4-tetraphenyl-1,3-butadiene wavelength shifter

    Science.gov (United States)

    Veloce, L. M.; Kuźniak, M.; Di Stefano, P. C. F.; Noble, A. J.; Boulay, M. G.; Nadeau, P.; Pollmann, T.; Clark, M.; Piquemal, M.; Schreiner, K.

    2016-06-01

    Liquid noble based particle detectors often use the organic wavelength shifter 1,1,4,4-tetraphenyl-1,3-butadiene (TPB) which shifts UV scintillation light to the visible regime, facilitating its detection, but which also can scintillate on its own. Dark matter searches based on this type of detector commonly rely on pulse-shape discrimination (PSD) for background mitigation. Alpha-induced scintillation therefore represents a possible background source in dark matter searches. The timing characteristics of this scintillation determine whether this background can be mitigated through PSD. We have therefore characterized the pulse shape and light yield of alpha induced TPB scintillation at temperatures ranging from 300 K down to 4 K, with special attention given to liquid noble gas temperatures. We find that the pulse shapes and light yield depend strongly on temperature. In addition, the significant contribution of long time constants above ~50 K provides an avenue for discrimination between alpha decay events in TPB and nuclear-recoil events in noble liquid detectors.

  12. 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.

  13. 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.

  14. 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...

  15. 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

  16. 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.

  17. 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

  18. 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)

  19. 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.).

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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 ...

  6. 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

  7. 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...

  8. Interferon-alpha-induced deficits in novel object recognition are rescued by chronic exercise

    OpenAIRE

    Fahey, B.; Barlow, S; Day, J S; O Mara, S. M.

    2008-01-01

    The anti-viral drug interferon-alpha (IFN-alpha) is widely-known to induce psychiatric and cognitive effects in patients. Previous work has shown that physical exercise can have a positive effect against brain insult. We investigated the effects of a clinically-comparable treatment regime of IFN-alpha on cognitive function in male Wistar rats and assessed the impact of chronic treadmill running on the deficits generated by IFN-alpha. We found that IFN-alpha induced significant impairments in ...

  9. 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.

  10. 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.

  11. 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.

  12. Tumor Necrosis Factor-alpha Induced Protein 3 Interacting Protein 1 Gene Polymorphisms and Pustular Psoriasis in Chinese Han Population

    Institute of Scientific and Technical Information of China (English)

    Jian-Wen Han; Yong Wang; Chulu Alateng; Hong-Bin Li; Yun-Hua Bai; Xin-Xiang Lyu; Rina Wu

    2016-01-01

    Background:Psoriasis is a common immune-mediated inflammatory dermatosis.Generalized pustular psoriasis (GPP) is the severe and rare type of psoriasis.The association between tumor necrosis factor-alpha induced protein 3 interacting protein 1 (TNIP1) gene and psoriasis was confirmed in people with multiple ethnicities.This study was to investigate the association between TNIP1 gene polymorphisms and pustular psoriasis in Chinese Han population.Methods:Seventy-three patients with GPP,67 patients with palmoplantar pustulosis (PPP),and 476 healthy controls were collected from Chinese Han population.Six single nucleotide polymorphisms (SNPs) of the TNIP1 gene,namely rs3805435,rs3792798,rs3792797,rs869976,rs17728338,and rs999011 were genotyped by using polymerase chain reaction-ligase detection reaction.Statistical analyses were performed using the PLINK 1.07 package.Allele frequencies and genotyping frequencies for six SNPs were compared by using Chi-square test,odd ratio (OR) (including 95% confidence interval) were calculated.The haplotype analysis was conducted by Haploview software.Results:The frequencies of alleles of five SNPs were significantly different between the GPP group and the control group (P≤ 7.22 × 10-3),especially in the GPP patients without psoriasis vulgaris (PsV).In the haplotype analysis,the most significantly different haplotype was H4:ACGAAC,with 13.1% frequency in the GPP group but only 3.4% in the control group (OR =4.16,P =4.459 × 10-7).However,no significant difference in the allele frequencies was found between the PPP group and control group for each of the six SNPs (P > 0.05).Conclusions:Polymorphisms in TNIP1 are associated with GPP in Chinese Han population.However,no association with PPP was found.These findings suggest that TNIP1 might be a susceptibility gene for GPP.

  13. Tumor Necrosis Factor-alpha Induced Protein 3 Interacting Protein 1 Gene Polymorphisms and Pustular Psoriasis in Chinese Han Population

    Science.gov (United States)

    Han, Jian-Wen; Wang, Yong; Alateng, Chulu; Li, Hong-Bin; Bai, Yun-Hua; Lyu, Xin-Xiang; Wu, Rina

    2016-01-01

    Background: Psoriasis is a common immune-mediated inflammatory dermatosis. Generalized pustular psoriasis (GPP) is the severe and rare type of psoriasis. The association between tumor necrosis factor-alpha induced protein 3 interacting protein 1 (TNIP1) gene and psoriasis was confirmed in people with multiple ethnicities. This study was to investigate the association between TNIP1 gene polymorphisms and pustular psoriasis in Chinese Han population. Methods: Seventy-three patients with GPP, 67 patients with palmoplantar pustulosis (PPP), and 476 healthy controls were collected from Chinese Han population. Six single nucleotide polymorphisms (SNPs) of the TNIP1 gene, namely rs3805435, rs3792798, rs3792797, rs869976, rs17728338, and rs999011 were genotyped by using polymerase chain reaction-ligase detection reaction. Statistical analyses were performed using the PLINK 1.07 package. Allele frequencies and genotyping frequencies for six SNPs were compared by using Chi-square test, odd ratio (OR) (including 95% confidence interval) were calculated. The haplotype analysis was conducted by Haploview software. Results: The frequencies of alleles of five SNPs were significantly different between the GPP group and the control group (P ≤ 7.22 × 10−3), especially in the GPP patients without psoriasis vulgaris (PsV). In the haplotype analysis, the most significantly different haplotype was H4: ACGAAC, with 13.1% frequency in the GPP group but only 3.4% in the control group (OR = 4.16, P = 4.459 × 10−7). However, no significant difference in the allele frequencies was found between the PPP group and control group for each of the six SNPs (P > 0.05). Conclusions: Polymorphisms in TNIP1 are associated with GPP in Chinese Han population. However, no association with PPP was found. These findings suggest that TNIP1 might be a susceptibility gene for GPP. PMID:27364786

  14. 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...

  15. 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...

  16. 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

  17. 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)

  18. Crocin suppresses tumor necrosis factor-alpha-induced cell death of neuronally differentiated PC-12 cells.

    Science.gov (United States)

    Soeda, S; Ochiai, T; Paopong, L; Tanaka, H; Shoyama, Y; Shimeno, H

    2001-11-01

    Crocus sativus L. is used in Chinese traditional medicine to treat some disorders of the central nervous system. Crocin is an ethanol-extractable component of Crocus sativus L.; it is reported to prevent ethanol-induced impairment of learning and memory in mice. In this study, we demonstrate that crocin suppresses the effect of tumor necrosis factor (TNF)-alpha on neuronally differentiated PC-12 cells. PC-12 cells dead from exposure to TNF-alpha show apoptotic morphological changes and DNA fragmentation. These hallmark features of cell death did not appear in cells treated in the co-presence of 10 microM crocin. Moreover, crocin suppressed the TNF-alpha-induced expression of Bcl-Xs and LICE mRNAs and simultaneously restored the cytokine-induced reduction of Bcl-X(L) mRNA expression. The modulating effects of crocin on the expression of Bcl-2 family proteins led to a marked reduction of a TNF-alpha-induced release of cytochrome c from the mitochondria. Crocin also blocked the cytochrome c-induced activation of caspase-3. To learn how crocin exhibits these anti-apoptotic actions in PC-12 cells, we tested the effect of crocin on PC-12 cell death induced by daunorubicin. We found that crocin inhibited the effect of daunorubicin as well. Our findings suggest that crocin inhibits neuronal cell death induced by both internal and external apoptotic stimuli.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. 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.

  9. 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...

  10. 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.

  11. 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

  12. 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...

  13. 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 ...

  14. Tumor necrosis factor (TNF)-alpha-induced IL-8 expression in gastric epithelial cells: role of reactive oxygen species and AP endonuclease-1/redox factor (Ref)-1.

    Science.gov (United States)

    O'Hara, Ann M; Bhattacharyya, Asima; Bai, Jie; Mifflin, Randy C; Ernst, Peter B; Mitra, Sankar; Crowe, Sheila E

    2009-06-01

    TNF-alpha contributes to oxidative stress via induction of reactive oxygen species (ROS) and pro-inflammatory cytokines. The molecular basis of this is not well understood but it is partly mediated through the inducible expression of IL-8. As redox factor-1 (Ref-1), is an important mediator of redox-regulated gene expression we investigated whether ROS and Ref-1 modulate TNF-alpha-induced IL-8 expression in human gastric epithelial cells. We found that TNF-alpha treatment of AGS cells enhanced nuclear expression of Ref-1 and potently induced IL-8 expression. Overexpression of Ref-1 enhanced IL-8 gene transcription at baseline and after TNF-alpha treatment whereas Ref-1 suppression and antioxidant treatment inhibited TNF-alpha-stimulated IL-8 expression. TNF-alpha-mediated enhancement of other pro-inflammatory chemokines like MIP-3 alpha and Gro-alpha was also regulated by Ref-1. Although TNF-alpha increased DNA binding activity of Ref-1-regulated transcription factors, AP-1 and NF-kappaB, to the IL-8 promoter, promoter activity was mainly mediated by NF-kappaB binding. Silencing of Ref-1 in AGS cells inhibited basal and TNF-alpha-induced AP-1 and NF-kappaB DNA binding activity, but not their nuclear accumulation. Collectively, we provide the first mechanistic evidence of Ref-1 involvement in TNF-alpha-mediated, redox-sensitive induction of IL-8 and other chemokines in human gastric mucosa. This has implications for understanding the pathogenesis of gastrointestinal inflammatory disorders.

  15. 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

  16. 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...

  17. 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.

  18. 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)

  19. 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.

  20. 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)

  1. 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)

  2. 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)

  3. 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)

  4. 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)

  5. 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

  6. 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...

  7. 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.

  8. 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.

  9. 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.

  10. 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.)

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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 ...

  16. 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)

  17. 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)

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.)

  3. 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.

  4. 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)

  5. 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

  6. 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)

  7. 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.

  8. New measurement of cross section of evaporation residues from $^{\\textrm{nat}}$Pr+$^{12}$C reaction: A comparative study on the production of $^{149}$Tb

    CERN Document Server

    Maiti, Moumita

    2011-01-01

    Production cross sections of evaporation residues, $^{149}$Tb, $^{150}$Tb, $^{151}$Tb and $^{149}$Gd, have been measured using the stacked foil technique followed by off-line $\\gamma$-spectrometry in $^{12}$C induced reactions on naturally abundant mononuclidic praseodymium target in the 44-79 MeV incident energy range. Measured data have been interpreted comparing with previous measurements and theoretical prediction of nuclear reaction model code \\textsc{PACE4}. About 5% and 14% of the theoretical cross sections have been measured for $^{149}$Tb and $^{150}$Tb, respectively. The new cross sections of $^{149}$Tb complement those measured earlier by $\\alpha$-spectrometry. Cross sections of $^{151}$Tb are comparable to the theory. Cumulative cross section of $^{149}$Gd sheds light on the nuclear reaction mechanism. In addition, a discussion has been made to show the feasibility of producing $^{149}$Tb in $p$- and $\\alpha$-induced reactions on gadolinium isotopes.

  9. 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.

  10. 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.

  11. 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...

  12. 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.

  13. 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.

  14. 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)

  15. 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.)

  16. 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%.

  17. 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)

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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)

  8. 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

  9. 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

  10. 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)

  11. 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...

  12. 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

  13. 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.

  14. 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

  15. Overexpression of cellular repressor of E1A-stimulated genes inhibits TNF-{alpha}-induced apoptosis via NF-{kappa}B in mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Cheng-Fei [Xijing Hospital, Fourth Military Medical University, Xi' an (China); Cardiovascular Research Institute and Department of Cardiology, Shenyang Northern Hospital, Shenyang (China); Han, Ya-Ling, E-mail: hanyaling53@gmail.com [Cardiovascular Research Institute and Department of Cardiology, Shenyang Northern Hospital, Shenyang (China); Jie-Deng,; Yan, Cheng-Hui; Jian-Kang,; Bo-Luan,; Jie-Li [Cardiovascular Research Institute and Department of Cardiology, Shenyang Northern Hospital, Shenyang (China)

    2011-03-25

    Research highlights: {yields} CREG protected MSCs from tumor necrosis factor-{alpha} (TNF-{alpha}) induced apoptosis. {yields} CREG inhibits the phosphorylation of I{kappa}B{alpha} and prevents the activation of NF-{kappa}B. {yields} CREG inhibits NF-{kappa}B nuclear translocation and pro-apoptosis protein transcription. {yields} CREG anti-apoptotic effect involves inhibition of the death receptor pathway. {yields} p53 is downregulated by CREG via NF-{kappa}B pathway under TNF-{alpha} stimulation. -- Abstract: Bone marrow-derived mesenchymal stem cells (MSCs) show great potential for therapeutic repair after myocardial infarction. However, poor viability of transplanted MSCs in the ischemic heart has limited their use. Cellular repressor of E1A-stimulated genes (CREG) has been identified as a potent inhibitor of apoptosis. This study therefore aimed to determine if rat bone marrow MSCs transfected with CREG-were able to effectively resist apoptosis induced by inflammatory mediators, and to demonstrate the mechanism of CREG action. Apoptosis was determined by flow cytometric and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling assays. The pathways mediating these apoptotic effects were investigated by Western blotting. Overexpression of CREG markedly protected MSCs from tumor necrosis factor-{alpha} (TNF-{alpha}) induced apoptosis by 50% after 10 h, through inhibition of the death-receptor-mediated apoptotic pathway, leading to attenuation of caspase-8 and caspase-3. Moreover, CREG resisted the serine phosphorylation of I{kappa}B{alpha} and prevented the nuclear translocation of the transcription factor nuclear factor-{kappa}B (NF-{kappa}B) under TNF-{alpha} stimulation. Treatment of cells with the NF-{kappa}B inhibitor pyrrolidine dithiocarbamate (PDTC) significantly increased the transcription of pro-apoptosis proteins (p53 and Fas) by NF-{kappa}B, and attenuated the anti-apoptotic effects of CREG on MSCs. The results of this study

  16. 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

  17. 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.)

  18. 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...

  19. 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.

  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. Interferon alpha-inducible protein 6 regulates NRASQ61K-induced melanomagenesis and growth

    Science.gov (United States)

    Gupta, Romi; Forloni, Matteo; Bisserier, Malik; Dogra, Shaillay Kumar; Yang, Qiaohong; Wajapeyee, Narendra

    2016-01-01

    Mutations in the NRAS oncogene are present in up to 20% of melanoma. Here, we show that interferon alpha-inducible protein 6 (IFI6) is necessary for NRASQ61K-induced transformation and melanoma growth. IFI6 was transcriptionally upregulated by NRASQ61K, and knockdown of IFI6 resulted in DNA replication stress due to dysregulated DNA replication via E2F2. This stress consequentially inhibited cellular transformation and melanoma growth via senescence or apoptosis induction depending on the RB and p53 pathway status of the cells. NRAS-mutant melanoma were significantly more resistant to the cytotoxic effects of DNA replication stress-inducing drugs, and knockdown of IFI6 increased sensitivity to these drugs. Pharmacological inhibition of IFI6 expression by the MEK inhibitor trametinib, when combined with DNA replication stress-inducing drugs, blocked NRAS-mutant melanoma growth. Collectively, we demonstrate that IFI6, via E2F2 regulates DNA replication and melanoma development and growth, and this pathway can be pharmacologically targeted to inhibit NRAS-mutant melanoma. DOI: http://dx.doi.org/10.7554/eLife.16432.001 PMID:27608486

  2. Tat-APE1/ref-1 protein inhibits TNF-alpha-induced endothelial cell activation.

    Science.gov (United States)

    Song, Yun Jeong; Lee, Ji Young; Joo, Hee Kyoung; Kim, Hyo Shin; Lee, Sang Ki; Lee, Kwon Ho; Cho, Chung-Hyun; Park, Jin Bong; Jeon, Byeong Hwa

    2008-03-28

    Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/ref-1) is a multifunctional protein involved both in DNA base excision repair and redox regulation. In this study we evaluated the protective role of Tat-mediated APE1/ref-1 transduction on the tumor necrosis factor (TNF)-alpha-activated endothelial activation in cultured human umbilical vein endothelial cells. To construct Tat-APE1/ref-1 fusion protein, human full length of APE1/ref-1 was fused with Tat-protein transduction domain. Purified Tat-APE1/ref-1 fusion protein efficiently transduced cultured endothelial cells in a dose-dependent manner and reached maximum expression at 1h after incubation. Transduced Tat-APE1/ref-1 showed inhibitory activity on the TNF-alpha-induced monocyte adhesion and vascular cell adhesion molecule-1 expression in cultured endothelial cells. These results suggest Tat-APE1/ref-1 might be useful to reduce vascular endothelial activation or vascular inflammatory disorders.

  3. 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)

  4. 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.

  5. 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)

  6. 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

  7. Interferin with thyroid scintigraphy: the effects of interferon alpha induced thyroid gland autoimmunity and dysfunction upon thyroid scintigraphy in patients with the hepatitis C virus

    International Nuclear Information System (INIS)

    Full text: The incidence of hepatitis C virus (HCV) infection is increasing. Interferon alpha therapy is often used to treat patients who are HCV positive. Thyroid gland autoimmunity and dysfunction has been reported to occur with variable frequency during INF-alpha therapy in patients with the HCV. This study reviews the scintigraphic findings of thyroid scans in such patients in order to assess for the effects on thyroid scintigraphy. To our knowledge, there has been no comprehensive study of this important occurrence to date. There were a number of patients with the HCV being treated at our institution between 23/09/1996 and 09/08/2000. Some of them received INF-alpha therapy, certain were subsequently diagnosed with thyroid gland autoimmunity and/or dysfunction. Eight were imaged with thyroid scintigraphy and reviewed. The scintigraphic findings in the 8 patients fell into two broad categories; 4 demonstrated changes of Graves' disease, and 3 changes of thyroiditis (1 of these was sub-acute). One hypothyroid patient with anti-thyroglobulin antibodies had normal thyroid scintigraphy. Six patients were found to have antithyroid antibodies. One patient with thyroiditis tested negative to antithyroid antibodies. One patient was not tested for antithyroid antibodies. Interferon alpha induced thyroid gland autoimmunity and/or dysfunction can markedly affect the thyroid scintigraphic findings of patients with the hepatitis C virus. This hitherto undescribed occurrence on thyroid scintigraphy has important practical implications of which Nuclear Medicine Specialists need to be aware in order to correctly interpret thyroid scintigraphy studies in such patients. The clinical presentation and effects on imaging appearances are varied. The Nuclear Medicine Specialist can play a central role in establishing the causal link. Awareness of this occurrence enables the Nuclear Medicine Specialist to add value to the referral. This occurrence will become an increasingly common

  8. 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.

  9. 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...

  10. 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...

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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)

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.)

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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)

  11. 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.

  12. 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.

  13. 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.)

  14. 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

  15. 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)

  16. 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

  17. 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.

  18. Nuclear reactions with 11C and 14O radioactive ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Fanqing

    2004-12-09

    Radioactive ion beams (RIBs) have been shown to be a useful tool for studying proton-rich nuclides near and beyond the proton dripline and for evaluating nuclear models. To take full advantage of RIBs, Elastic Resonance Scattering in Inverse Kinematics with Thick Targets (ERSIKTT), has proven to be a reliable experimental tool for investigations of proton unbound nuclei. Following several years of effort, Berkeley Experiments with Accelerated Radioactive Species (BEARS), a RIBs capability, has been developed at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. The current BEARS provides two RIBs: a 11C beam of up to 2x108 pps intensity on target and an 14O beam of up to 3x104 pps intensity. While the development of the 11C beam has been relatively easy, a number of challenges had to be overcome to obtain the 14O beam. The excellent 11C beam has been used to investigate several reactions. The first was the 197Au(11C,xn)208-xnAt reaction, which was used to measure excitation functions for the 4n to 8n exit channels. The measured cross sections were generally predicted quite well using the fusion-evaporation code HIVAP. Possible errors in the branching ratios of ?? decays from At isotopes as well as the presence of incomplete fusion reactions probably contribute to specific overpredictions. 15F has been investigated by the p(14O,p)14O reaction with the ERSIKTT technology. Several 14O+p runs have been performed. Excellent energy calibration was obtained using resonances from the p(14N,p)14N reaction in inverse kinematics, and comparing the results to those obtained earlier with normal kinematics. The differences between 14N+p and 14O+p in the stopping power function have been evaluated for better energy calibration. After careful calibration, the energy levels of 15F were fitted with an R-matrix calculation. Spins and parities were assigned to the two observed resonances. This new measurement of the 15F ground state supports the disappearance of the Z

  19. Nuclear reactions with 11C and 14O radioactive ion beams

    International Nuclear Information System (INIS)

    Radioactive ion beams (RIBs) have been shown to be a useful tool for studying proton-rich nuclides near and beyond the proton dripline and for evaluating nuclear models. To take full advantage of RIBs, Elastic Resonance Scattering in Inverse Kinematics with Thick Targets (ERSIKTT), has proven to be a reliable experimental tool for investigations of proton unbound nuclei. Following several years of effort, Berkeley Experiments with Accelerated Radioactive Species (BEARS), a RIBs capability, has been developed at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. The current BEARS provides two RIBs: a 11C beam of up to 2x108 pps intensity on target and an 14O beam of up to 3x104 pps intensity. While the development of the 11C beam has been relatively easy, a number of challenges had to be overcome to obtain the 14O beam. The excellent 11C beam has been used to investigate several reactions. The first was the 197Au(11C,xn)208-xnAt reaction, which was used to measure excitation functions for the 4n to 8n exit channels. The measured cross sections were generally predicted quite well using the fusion-evaporation code HIVAP. Possible errors in the branching ratios of ?? decays from At isotopes as well as the presence of incomplete fusion reactions probably contribute to specific overpredictions. 15F has been investigated by the p(14O,p)14O reaction with the ERSIKTT technology. Several 14O+p runs have been performed. Excellent energy calibration was obtained using resonances from the p(14N,p)14N reaction in inverse kinematics, and comparing the results to those obtained earlier with normal kinematics. The differences between 14N+p and 14O+p in the stopping power function have been evaluated for better energy calibration. After careful calibration, the energy levels of 15F were fitted with an R-matrix calculation. Spins and parities were assigned to the two observed resonances. This new measurement of the 15F ground state supports the disappearance of the Z = 8

  20. Simulation mechanisms of low energy nuclear reaction using super flow energy external fields

    International Nuclear Information System (INIS)

    Full text: The review of possible stimulation mechanisms of the LENR (low energy nuclear reactions) is represented. We have concluded that transamination of nuclei at low energies and excess heat are possible in the framework of the modern physical theory - the universal resonance synchronization principle and based on its different enhancement mechanisms of reaction rates are responsible for these processes. The excitation nd ionization of atom may play role as trigger for LERN. Investigation of this phenomenon requires knowledge of different branches if science: nuclear and atomic physics, chemistry and electrochemistry, condensed matter and solid state physics. The results of this research field can provide a new source of energy, substances and technologies. The puzzle of poor re-productivity of experimental data in due ti the fact LENR occurs in open systems and it is extremely sensitive to parameters of external fields and systems. Classical re-productivity principle should be reconsidered for LENR experiments. Poor re-productivity and unexpected results do not means that the experiment is wrong. Our main conclusion: LENR may be understand in terms of the modern theory without any violation of the basic physics. 2) Weak and electromagnetic interactions may show the strong influence of the surrounding conditions on the nuclear processes. 3) Universal resonance synchronization principle is a key issue to make a bridge between various scales of interactions and it is responsible for self-organization of hierarchical systems independent of substances, fields and interactions. We bring some arguments in favor of the mechanism - order based on order - declared by Schroedinger in fundamental problem of contemporary science. 4) The universal resonance synchronization principle became a fruitful interdisciplinary science of general laws of self-organized processes in different branches of physics because it is consequence of the energy conservation law and resonance

  1. 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

  2. Center of Nuclear Physical Data (CNPD)

    International Nuclear Information System (INIS)

    This it the progress report of the Center of Nuclear Physical Data (CNPD) of the Russian Federal Nuclear Center-VNIIEF, Sarov, Russia. There have been compiled data on alpha-induced reactions for the nuclei with 8≤Z≤32 (24Mg, 28Si, 32S, 36Ar, 40Ca) and Ecm≤20 MeV. Processing of compiled data allowed obtaining parameters of Woods-Saxon potential with volume absorption in the α-particle energy range lower and higher than the Coulomb barrier for the 36Ar+α and 40Ca+α systems. They were obtained as a result of existing optical potentials modification and are intended to be used in a statistical Houser-Feshbach model widely applied in astrophysical calculations of nuclear reaction cross-sections. This year there has been completed the creation of a new 'SaBa' database version' library of evaluated and experimental data on charged particles interaction with light nuclei. The data on more than 120 reaction channels are available in it today. The library is oriented to solve astrophysics problems and contains information useful for the developers of astrophysics applications

  3. Nuclear chemistry fifty years after the discovery of artificial radioactivity

    International Nuclear Information System (INIS)

    In January 1934, the observation and the chemical identification of radiophosphorus as a reaction product in the bombardment of Aluminium by alpha particles have been the first step of a new scientific branch: Nuclear Chemistry. We describe here how this discovery in itself contains the frame of all the development which has followed. It consisted in four stages, each of them being a crucial starting point. The first one is the possibility for a total balance of the nuclear reaction in the exit channels, so that reaction mechanisms can be studied. The second, the most important perhaps, is the opening of nuclear synthesis. Nuclear chemists can now interfere into nuclear matter and instead of staying as observers of the radioactive decays of natural isotopes, they were able to build up a numerous chart of various nuclear species, going step by step further and further away from the nuclear stability conditions. The third aspect of the discovery was the appearance of a new mode of radioactive decay with the production of the first particle an antimater. 50 years later, the instability due to a much larger excess of protons is known to induce the proton emission radioactivity for new species like 109I or 115Cs, in the vicinity of proton unstability. Finally, the last point, so fertile for the future, was the observation of a neutron in the exit channel, so that neutron fluxes could result from alpha induced nuclear reactions and became such a strong tool for the production of transuranium elements and for nuclear fission. In the present survey, the wide interest of the second point, i.e. the nuclear synthesis, is emphasized, as well as the huge change in the technical methods

  4. STAT5 activation by human GH protects insulin-producing cells against interleukin-1beta, interferon-gamma and tumour necrosis factor-alpha-induced apoptosis independent of nitric oxide production

    DEFF Research Database (Denmark)

    Jensen, Janne; Galsgaard, Elisabeth D; Karlsen, Allan E;

    2005-01-01

    possible targets for the STAT5-mediated protection of INS-1E cells, we studied the effect of hGH on activation of the transcription factors STAT1 and nuclear factor-kappaB (NF-kappaB) by IFN-gamma and IL-1beta+TNF-alpha respectively. Gel retardation experiments showed that hGH affects neither IFN......-gamma+TNF-alpha-induced STAT1 DNA binding nor IL-1beta and IFN-gamma+TNF-alpha-induced NFkappaB DNA binding. The lack of influence of hGH on cytokine-mediated activation of STAT1 and NFkappaB is in accordance with the finding that hGH had only a minor effect on cytokine-induced inducible nitric oxide synthase (iNOS) gene...... and in the presence of cytotoxic cytokines. In conclusion, these results suggested that GH and PRL protect beta-cells against cytotoxic cytokines via STAT5-dependent mechanisms distal to iNOS activation possibly at the level of Bcl-xL....

  5. Alpha capture reaction cross section measurements on Sb isotopes by activation method

    Science.gov (United States)

    Korkulu, Z.; Özkan, N.; Kiss, G. G.; Szücs, T.; Fülöp, Zs; Güray, R. T.; Gyürky, Gy; Halász, Z.; Somorjai, E.; Török, Zs; Yalçin, C.

    2016-01-01

    Alpha induced reactions on natural and enriched antimony targets were investigated via the activation technique in the energy range from 9.74 MeV to 15.48 MeV, close to the upper end of the Gamow window at a temperature of 3 GK relevant to the γ-process. The experiments were carried out at the Institute for Nuclear Research, the Hungarian Academy of Sciences (MTA Atomki). 121Sb(α,γ)125I, 121Sb(α,n)124I and 123Sb(α,n)126I reactions were measured using a HPGe detector. In this work, the 121Sb(α,n)124 cross section results and the comparison with the theoretical predictions (obtained with standard settings of the statistical model codes NON-SMOKER and TALYS) were presented.

  6. Particle-gamma and particle-particle correlations in nuclear reactions using Monte Carlo Hauser-Feshback model

    Energy Technology Data Exchange (ETDEWEB)

    Kawano, Toshihiko [Los Alamos National Laboratory; Talou, Patrick [Los Alamos National Laboratory; Watanabe, Takehito [Los Alamos National Laboratory; Chadwick, Mark [Los Alamos National Laboratory

    2010-01-01

    Monte Carlo simulations for particle and {gamma}-ray emissions from an excited nucleus based on the Hauser-Feshbach statistical theory are performed to obtain correlated information between emitted particles and {gamma}-rays. We calculate neutron induced reactions on {sup 51}V to demonstrate unique advantages of the Monte Carlo method. which are the correlated {gamma}-rays in the neutron radiative capture reaction, the neutron and {gamma}-ray correlation, and the particle-particle correlations at higher energies. It is shown that properties in nuclear reactions that are difficult to study with a deterministic method can be obtained with the Monte Carlo simulations.

  7. Theoretical nuclear reaction and structure studies using kaons and photons: Final technical report, June 1, 1979--September 1, 1988

    International Nuclear Information System (INIS)

    The research topics of this program have involved several sectors of nuclear and particle physics. In addition to studying reactions involving kaons and photons/endash/a project treating K+ meson elastic scattering, K+ photo and electroproduction, hypernuclear photo-excitation and photo-proton knockout reactions with delta isobar formation, this research program has also investigated symmetry principles and their usefulness in reaction theory. This paper provides a brief overview of the major scientific findings and cite key, representative publications containing full details

  8. A20 overexpression under control of mouse osteocalcin promoter in MC3T3-E1 cells inhibited tumor necrosis factor-alpha-induced apoptosis

    Institute of Scientific and Technical Information of China (English)

    Yue-juan QIN; Zhen-lin ZHANG; Lu-yang YU; Jin-wei HE; Ya-nan HOU; Tian-jin LIU; Jia-cai WU; Song-hua WU; Li-he GUO

    2006-01-01

    Aim: To construct an A20 expression vector under the control of mouse osteocalcin promoter (OC-A20), and investigate osteoblastic MC3T3-E1 cell line, which stably overexpresses A20 protein prevented tumor necrosis factor (TNF)-alpha-induced apoptosis. Methods: OC-A20 vector was constructed by fusing a fragment of the mouse osteocalcin gene-2 promoter with human A20 complementary DNA. Then the mouse MC3T3-E1 cell line, stably transfected by A20, was established. The expression of A20 mRNA and A20 protein in the cells were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. To determine the specificity of A20 expression in osteoblast, the mouse osteoblastic MC3T3-E1 cell line and mouse embryo fibro-blast NIH3T3 cell line were transiently transfected with OC-A20. The anti-apoptotic role of A20 in MC3T3-E1 cells was determined by Flow cytometric analysis (FACS), terminal dUTP nick endo-labeling (TUNEL) and DNA gel electrophoresis analysis (DNA Ladder), respectively. Results: Weak A20 expression was found in MC3T3-El cells with the primers of mouse A20. A20 mRNA and A20 protein expression were identified in MC3T3-E1 cells transfected with OC-A20 using RT-PCR and Western blot analysis. Only A20 mRNA expression was found in MC3T3-E1 cell after MC3T3-E1 cells and NIH3T3 cells were transient transfected with OC-A20. A decrease obviously occurred in the rate of apoptosis in the OC-A20 group compared with the empty vector (pcDNA3) group by FACS (P<0.001). A significant increase in TUNEL positive staining was found in the pcDNA group compared with OC-A20 group (P<0.001). Simultaneously, similar effects were demonstrated in DNA gel electrophoresis analysis. Conclusion: We constructed an osteoblast-specific expression vector that expressed A20 protein in MC3T3-E1 cells and confirmed that A20 protects osteoblast against TNF-alpha-induced apoptosis.

  9. 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.

  10. On the implementation of a chain nuclear reaction of thermonuclear fusion on the basis of the p+11B process

    Science.gov (United States)

    Belyaev, V. S.; Krainov, V. P.; Zagreev, B. V.; Matafonov, A. P.

    2015-07-01

    Various theoretical and experimental schemes for implementing a thermonuclear reactor on the basis of the p+11B reaction are considered. They include beam collisions, fusion in degenerate plasmas, ignition upon plasma acceleration by ponderomotive forces, and the irradiation of a solid-state target from 11B with a proton beam under conditions of a Coulomb explosion of hydrogen microdrops. The possibility of employing ultra-short high-intensity laser pulses to initiate the p+11B reaction under conditions far from thermodynamic equilibrium is discussed. This and some other weakly radioactive thermonuclear reactions are promising owing to their ecological cleanness—there are virtually no neutrons among fusion products. Nuclear reactions that follow the p+11B reaction may generate high-energy protons, sustaining a chain reaction, and this is an advantage of the p+11B option. The approach used also makes it possible to study nuclear reactions under conditions close to those in the early Universe or in the interior of stars.

  11. Investigations of nuclear structure and nuclear reactions induced by complex projectiles. Progress report for the period September 1, 1992--August 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Sarantites, D.G.

    1993-09-06

    This is a progress report on activities of the Washington University group in nuclear reaction studies for the period Sept 1, 1992 to Aug 31, 1993. This group has a research program which touches five areas of nuclear physics: nuclear structure studies at high spin; studies at the interface between structure and reactions; production and study of hot nuclei; reaction mechanism studies; development and use of novel techniques and instrumentation in the above areas of research. Specific activities of the group include in part: superdeformation in {sup 82}Sr; structure of and identical bands in {sup 182}Hg and {sup 178}Pt; a highly deformed band in {sup 136}Pm; particle decay of the {sup 164}Yb compound nucleus; fusion reactions; proton evaporation; two-proton decay of {sup 12}O; modeling and theoretical studies; excited {sup 16}O disassembly into four alpha particles; {sup 209}Bi + {sup 136}Xe collisions at 28.2 MeV/amu; and development work on 4{pi} solid angle gamma detectors, and x-ray detectors.

  12. Studies on the reaction mechanism of the muon induced nuclear fission

    International Nuclear Information System (INIS)

    The mass and energy distribution of the fission fragments after muon induced nuclear fission allows the determination of the mean excitation energy of the fissioning nucleus after muon capture. By the systematic comparison with a mass distribution of a corresponding reaction for the first time for this an accuracy of about 1 MeV could be reached. Theoretical calculations on the excitation probability in the muon capture allow in connection with the fission probability an estimating calculation of this energy. The experimental result represents by this a test criterium for the valuation of the theoretical calculation. The measured probabilities for the occurrence of radiationless transitions in the muonic γ cascade of 237Np permit an indirect experimental determination of the barrier enhancement which causes the muon present during the fission process. The value found for this extends to 0.75+-0.1 MeV. A change of the mass distribution by the muon cannot be detected in the nuclides 235U, 237Np, and 242Pu studied here. Only the mean total kinetic energy of the fission products is reduced in these three nuclides in the prompt μ- induced fission by 1 to 2 MeV. For this result the incomplete screening of the nuclear charge during the fission process is made responsible. A mass dependence of this reduction has not been stated. Because the muon has appearently no influence on the mass splitting it can be valied as nearly ideal particle in order to study the hitherto little studied dynamics of the fission process. (orig.)

  13. Study of the Nuclear Transparency in $\\alpha$ + A Reactions at Energies $\\geq$ 12 GeV/nucleon

    CERN Multimedia

    2002-01-01

    The question about transparency is crucial for heavy ion reaction studies. If the transparency is low at 10-15 GeV per nucleon then very large baryon densities can be achieved in this energy range, maybe enough to produce quark-gluon plasma in U+U collisions. We propose to measure, event by event, pseudo-rapidity and multiplicity distributions of singly charged relativistic particles (@b~$>$~0.7) globally and in selected regions of rapidity as well as multiplicities of recoiling protons (30-400~Me charged nuclear fragments. These studies will explore general features of @a+A reactions at energies @$>$~12~GeV/nucleon. The main goal of the experiment is to measure the transparency of nuclear matter in this energy range. The detector will be nuclear emulsion.

  14. Activation cross-sections of deuteron induced nuclear reactions on neodymium up to 50 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Tárkányi, F.; Takács, S. [Institute for Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Ditrói, F., E-mail: ditroi@atomki.hu [Institute for Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel (VUB), Brussels (Belgium); Yamazaki, H.; Baba, M.; Mohammadi, A. [Cyclotron Radioisotope Center (CYRIC), Tohoku University, Sendai (Japan); Ignatyuk, A.V. [Institute of Physics and Power Engineering (IPPE), Obninsk (Russian Federation)

    2014-04-01

    Highlights: • Experimental excitation function of deuteron induced reactions on natural Nd. • Model code calculations with EMPIRE-D, ALICE-D and TALYS (TENDL-2012). • Physical yield calculation and comparison. • Discussion of medical and industrial applications. - Abstract: In the frame of a systematic study of activation cross sections of deuteron induced nuclear reactions on rare earths, the reactions on neodymium for production of therapeutic radionuclides were measured for the first time. The excitation functions of the {sup nat}Nd(d,x) {sup 151,150,149,148m,148g,146,144,143}Pm, {sup 149,147,139m}Nd, {sup 142}Pr and {sup 139g}Ce nuclear reactions were assessed by using the stacked foil activation technique and high resolution γ-spectrometry. The experimental excitation functions were compared to the theoretical predictions calculated with the modified model codes ALICE-IPPE-D and EMPIRE-II-D and with the data in the TENDL-2012 library based on latest version of the TALYS code. The application of the data in the field of medical isotope production and nuclear reaction theory is discussed.

  15. On-line monitoring of chemical reactions by using bench-top nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Danieli, E; Perlo, J; Duchateau, A L L; Verzijl, G K M; Litvinov, V M; Blümich, B; Casanova, F

    2014-10-01

    Real-time nuclear magnetic resonance (NMR) spectroscopy measurements carried out with a bench-top system installed next to the reactor inside the fume hood of the chemistry laboratory are presented. To test the system for on-line monitoring, a transfer hydrogenation reaction was studied by continuously pumping the reaction mixture from the reactor to the magnet and back in a closed loop. In addition to improving the time resolution provided by standard sampling methods, the use of such a flow setup eliminates the need for sample preparation. Owing to the progress in terms of field homogeneity and sensitivity now available with compact NMR spectrometers, small molecules dissolved at concentrations on the order of 1 mmol L(-1) can be characterized in single-scan measurements with 1 Hz resolution. Owing to the reduced field strength of compact low-field systems compared to that of conventional high-field magnets, the overlap in the spectrum of different NMR signals is a typical situation. The data processing required to obtain concentrations in the presence of signal overlap are discussed in detail, methods such as plain integration and line-fitting approaches are compared, and the accuracy of each method is determined. The kinetic rates measured for different catalytic concentrations show good agreement with those obtained with gas chromatography as a reference analytical method. Finally, as the measurements are performed under continuous flow conditions, the experimental setup and the flow parameters are optimized to maximize time resolution and signal-to-noise ratio. PMID:25111845

  16. Redox reactions induced by hydrogen in deep geological nuclear waste disposal

    International Nuclear Information System (INIS)

    The aim of this study is to evaluate the abiotic hydrogen reactivity in deep geological nuclear waste storage. One crucial research interest concerns the role of H2 as a reducing agent for the aqueous/mineral oxidised species present in the site. Preliminary batch experiments carried out with Callovo-Oxfordian argillite, synthetic pore water and H2 gas lead to an important H2S production, in only few hours at 250 C to few months at 90 C. In order to explore whether H2S can originate from sulphate or pyrite (few percents of the argillite) reduction we performed dedicated experiments. Sulphate reduction experimented in di-phasic systems (water+gas) at 250-300 C and under 4 to 16 bar H2 partial pressure exhibits a high activation energy (131 kJ/mol) and requires H2S initiation and low pH condition as already observed in other published TSR experiments. The corresponding half-life is 210,000 yr at 90 C (thermal peak of the site). On the contrary, pyrite reduction into pyrrhotite by H2 occurs in few days at temperature as low as 90 C at pH buffered by calcite. The rate of the reaction could be described by a diffusion-like rate law in the 90-180 C temperature interval. The obtained results suggest that pyrite reduction is a process controlled both by the H2 diffusion across the pyrrhotite pits increasing during reaction progress and the reductive dissolution of pyrite. These new kinetics data can be applied in computation modelling, to evaluate the degree and extent of gas pressure buildup by taking into account the H2 reactive geochemistry. (author)

  17. Nuclear attitudes and reactions: associations with depression, drug use, and quality of life

    International Nuclear Information System (INIS)

    For 40 years the world has lived with the threat of nuclear war and, recently, with the possibility of nuclear power plant accidents. Although virtually every generation must confront various national or international crises, the threat of nuclear war is unprecedented in its destructive potential. This study is an attempt to assess attitudes and amount of distress associated with the ever-present threat of nuclear war and the possibility of accidents at nuclear power plants. The Nuclear Attitudes Questionnaire (NAQ) consists of 15 items and was administered to 722 young adults who have grown up in the nuclear age. The items were found to reflect four latent factors of nuclear concern, nuclear support, fear of the future, and nuclear denial, all of which in turn represent a second-order construct of nuclear anxiety. Women reported significantly more nuclear concern, less nuclear support, more fear of the future, and less nuclear denial than did men. In latent-variable models, nuclear anxiety was found to be significantly associated with less purpose in life, less life satisfaction, more powerlessness, more depression, and more drug use. It is concluded that the threat of nuclear war and accidents is significantly related to psychological distress and may disturb normal maturational development

  18. 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...

  19. Study of nuclear reactions producing 36Cl by micro-AMS

    Science.gov (United States)

    Luís, H.; Jesus, A. P.; Fonseca, M.; Cruz, J.; Galaviz, D.; Franco, N.; Alves, E.

    2016-01-01

    36Cl is one of several short to medium lived isotopes (as compared to the earth age) whose abundances at the earlier solar system may help to clarify its formation process. There are two generally accepted possible models for the production of this radionuclide: it originated from the ejecta of a nearby supernova (where 36Cl was most probably produced in the s-process by neutron irradiation of 35Cl) and/or it was produced by in-situ irradiation of nebular dust by energetic particles (mostly, p, a, 3He -X-wind irradiation model). The objective of the present work is to measure the cross section of the 37Cl(p,d)36Cl and 35Cl(d,p)36Cl nuclear reactions, by measuring the 36Cl content of AgCl samples (previously bombarded with high energy protons and deuterons) with AMS, taking advantage of the very low detection limits of this technique for chlorine measurements. For that, the micro-AMS system of the LF1/ITN laboratory had to be optimized for chlorine measurements, as to our knowledge this type of measurements had never been performed in such a system (AMS with micro-beam). Here are presented the first results of these developments, namely the tests in terms of precision and reproducibility that were done by comparing AgCl blanks irradiated at the Portuguese National Reactor with standards produced by the dilution of the NIST SRM 4943 standard material.

  20. Development of a system for measuring fluoride distribution in teeth using a nuclear reaction

    International Nuclear Information System (INIS)

    Fluoride (F) distributions in a synthesized hydroxyl apatite (HAp) block of uniform structure and in teeth were measured using in-air micro-PIGE (particle induced gamma-ray emission) and micro-PIXE system, which was developed at the Japan Atomic Energy Agency (JAEA) in Takasaki. We used a nuclear reaction 19F(p,αγ)16O to measure F density. The characteristic important feature of this technique is that it can measure F quantitatively in a microscopic area of the specimen placed in air. A surface of the HAp, the enamel buccal surface of a human molar, and a class V cavity wall in dentin were applied a sodium fluoride solution (NaF) four times and immersed in a normal saline solution. After one month, specimens were cut longitudinally. The F distributions were measured from the surface toward the inner part of the cut surface. The F penetration into specimens following NaF application was quantitatively configured in a two-dimensional mapping form. This method is quite useful for characterizing F distribution in a microscopic area of a tooth. (author)

  1. Interplay between diffusion, accretion and nuclear reactions in the atmospheres of Sirius and Przybylski's star

    CERN Document Server

    Yushchenko, A; Goriely, S; Shavrina, A; Kang, Y W; Rostopchin, S; Valyavin, G; Mkrtichian, D; Hatzes, A; Lee, B C; Kim, C; Yushchenko, Alexander; Gopka, Vera; Goriely, Stephane; Shavrina, Angelina; Kang, Young Woon; Rostopchin, Sergey; Valyavin, Gennady; Mkrtichian, David; Hatzes, Artie; Lee, Byeong-Cheol; Kim, Chulhee

    2006-01-01

    The abundance anomalies in chemically peculiar B-F stars are usually explained by diffusion of chemical elements in the stable atmospheres of these stars. But it is well known that Cp stars with similar temperatures and gravities show very different chemical compositions. We show that the abundance patterns of several stars can be influenced by accretion and (or) nuclear reactions in stellar atmospheres. We report the result of determination of abundances of elements in the atmosphere of hot Am star: Sirius A and show that Sirius A was contaminated by s-process enriched matter from Sirius B (now a white dwarf). The second case is Przybylski's star. The abundance pattern of this star is the second most studied one after the Sun with the abundances determined for about 60 chemical elements. Spectral lines of radioactive elements with short decay times were found in the spectrum of this star. We report the results of investigation on the stratification of chemical elements in the atmosphere of Przybylski's star ...

  2. Melter Feed Reactions at T ≤ 700°C for Nuclear Waste Vitrification

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Kai [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hrma, Pavel R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rice, Jarrett A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Riley, Brian J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schweiger, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Crum, Jarrod V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-07-23

    Batch reactions and phase transitions in a nuclear waste feed heated at 5 K min-1 up to 600°C were investigated by optical microscopy, scanning electron microscopy with energy dispersive X-ray spectrometer, and X-ray diffraction. Quenched samples were leached in deionized water at room temperature and 80°C to extract soluble salts and early glass-forming melt, respectively. To determine the content and composition of leachable phases, the leachates were analyzed by the inductively-coupled plasma spectroscopy. By ~400°C, gibbsite and borax lost water and converted to amorphous and intermediate crystalline phases. Between 400°C and 600°C, the sodium borate early glass-forming melt reacted with amorphous aluminum oxide and calcium oxide to form intermediate products containing Al and Ca. At ~600°C, half Na and B converted to the early glass-forming melt, and quartz began to dissolve in the melt.

  3. Modeled Neutron and Charged-Particle Induced Nuclear Reaction Cross Sections for Radiochemistry in the Region of Yttrium, Zirconium, Niobium, and Molybdenum

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-06-13

    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, proton, and deuteron induced nuclear reaction cross sections for targets ranging from strontium (Z = 38) to rhodium (Z = 45).

  4. Deuteron Induced ( d,p) and ( d,2p) Nuclear Reactions up to 50 MeV

    Science.gov (United States)

    Yiğit, M.; Tel, E.; Kara, A.

    2013-06-01

    Many studies have shown that the nuclear reactions of charged particles with nuclei are very important in many fields of nuclear physics. The interactions of deuterons with nuclei have been especially the subject of common research in the history of nuclear physics. Moreover, the knowledge of cross section for deuteron-nucleus interactions are required for various application such as space applications, accelerator driven sub-critical systems, nuclear medicine, nuclear fission reactors and controlled thermonuclear fusion reactors. Particularly, the future of controlled thermonuclear fusion reactors is largely dependent on the nuclear reaction cross section data and the selection of structural fusion materials. Finally, the reaction cross section data of deuteron induced reactions on fusion structural materials are of great importance for development and design of both experimental and commercial fusion devices. In this work, reaction model calculations of the cross sections of deuteron induced reactions on structural fusion materials such as Al ( Aluminium), Ti ( Titanium), Cu ( Copper), Ni ( Nickel), Co ( Cobalt), Fe ( Iron), Zr ( Zirconium), Hf ( Hafnium) and Ta ( Tantalum) have been investigated. The new calculations on the excitation functions of 27 Al( d,2p) 27 Mg, 47 Ti( d,2p) 47 Sc, 65 Cu( d,2p) 65 Ni, 58 Ni( d,2p) 58 Co, 59 Co( d,2p) 59 Fe, 58 Fe( d,p) 59 Fe, 96 Zr( d,p) 97 Zr, 180 Hf ( d,p) 181 Hf and 181 Ta( d,p) 182 Ta have been carried out for incident deuteron energies up to 50 MeV. In these calculations, the equilibrium and pre-equilibrium effects for ( d,p) and ( d,2p) reactions have been investigated. The equilibrium effects are calculated according to the Weisskopf-Ewing ( WE) Model. The pre-equilibrium calculations involve the new evaluated the Geometry Dependent Hybrid Model ( GDH) and Hybrid Model. In the calculations the program code ALICE/ASH was used. The calculated results are discussed and compared with the experimental data taken from the

  5. Preface to the Special Issue: International Workshop on Nuclear Dynamics in Heavy-Ion Reactions and Neutron Stars

    International Nuclear Information System (INIS)

    The International Workshop on Nuclear Dynamics in Heavy-Ion Reactions and Neutron Stars was held from 9-14 July 2007 in Beijing. This workshop was organized by Beijing Normal University, Shanghai Institute of Applied Physics of the Chinese Academy of Sciences, Shanghai Jiatong University, Huzhou Teachers' College, Institute of High Energy Physics of the Chinese Academy of Sciences, Laboratori Nazionali del Sud (LNS) of Istituto Nazionale di Fisica Nucleare (INFN), University of Catania, and Texas A & M University-Commerce. More than 60 physicists, from local and abroad, participated in the workshop and more than 35 of them presented talks. The workshop covered a great variety of hot topics, including nuclear reaction dynamics and isospin effects in heavy-ion collisions, EOS of nuclear matter and neutron stars, phase transitions of nuclear matter (liquid-to-gas in low energy HIC, QGP in high energy HIC, color superconductivity), exotic nuclei and structure of hadronic matter in the high density regime (neutron star inner core).

  6. The role of nuclear reactions in Monte Carlo calculations of absorbed and biological effective dose distributions in hadron therapy

    CERN Document Server

    Brons, S; Elsässer, T; Ferrari, A; Gadioli, E; Mairani, A; Parodi, K; Sala, P; Scholz, M; Sommerer, F

    2010-01-01

    Monte Carlo codes are rapidly spreading among hadron therapy community due to their sophisticated nuclear/electromagnetic models which allow an improved description of the complex mixed radiation field produced by nuclear reactions in therapeutic irradiation. In this contribution results obtained with the Monte Carlo code FLUKA are presented focusing on the production of secondary fragments in carbon ion interaction with water and on CT-based calculations of absorbed and biological effective dose for typical clinical situations. The results of the simulations are compared with the available experimental data and with the predictions of the GSI analytical treatment planning code TRiP.

  7. Report on the consultants' meeting on co-ordination of the nuclear reaction data centers (technical aspects)

    International Nuclear Information System (INIS)

    The report summarizes the co-ordination meeting of the network of Nuclear Reaction Data Centres organized by the IAEA in 1997. The meeting was attended by technical staff from ten member centres of the network (representing USA, Russia, China, Japan, Hungary, OECD-NEA and IAEA) to discuss technical matters of the nuclear data compilation and exchange by means of the jointly operated computerized systems CINDA, EXFOR, ENDF and others. Observers from Belgium and Ukraine also attended the meeting. The document includes status reports of all centres and selected working papers

  8. Activation cross-sections of longer lived radioisotopes of deuteron induced nuclear reactions on terbium up to 50 MeV

    CERN Document Server

    Tárkányi, F; Ditrói, F; Hermanne, A; Ignatyuk, A V

    2013-01-01

    Experimental cross-sections are presented for the first time for the 159Tb(d,xn)155,157,159Dy, 155,156,160Tb and 153Gd nuclear reactions up to 50 MeV. The experimental data are compared with theoretical predictions of the ALICE, EMPIRE and TALYS nuclear reaction codes. Integral thick-target yields are also derived for the reaction products that have practical applications.

  9. Process and kinetics of the fundamental radiation-electrochemical reactions in the primary coolant loop of nuclear reactors

    International Nuclear Information System (INIS)

    In spite of the rather broad title of this report, its major part is devoted to the corrosion problems at the RA reactor, i.e. causes and consequences of the reactor shutdown in 1979 and 1982. Some problems of reactor chemistry are pointed out because they are significant for future reactor operation. The final conclusion of this report is that corrosion processes in the primary coolant circuit of the nuclear reactor are specific and that radiation effects cannot be excluded when processes and reaction kinetics are investigated. Knowledge about the kinetics of all the chemical reactions occurring in the primary coolant loop are of crucial significance for safe and economical reactor operation

  10. Detailed Reaction Kinetics for CFD Modeling of Nuclear Fuel Pellet Coating for High Temperature Gas-Cooled Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Battaglia, Francine

    2008-11-29

    The research project was related to the Advanced Fuel Cycle Initiative and was in direct alignment with advancing knowledge in the area of Nuclear Fuel Development related to the use of TRISO fuels for high-temperature reactors. The importance of properly coating nuclear fuel pellets received a renewed interest for the safe production of nuclear power to help meet the energy requirements of the United States. High-temperature gas-cooled nuclear reactors use fuel in the form of coated uranium particles, and it is the coating process that was of importance to this project. The coating process requires four coating layers to retain radioactive fission products from escaping into the environment. The first layer consists of porous carbon and serves as a buffer layer to attenuate the fission and accommodate the fuel kernel swelling. The second (inner) layer is of pyrocarbon and provides protection from fission products and supports the third layer, which is silicon carbide. The final (outer) layer is also pyrocarbon and provides a bonding surface and protective barrier for the entire pellet. The coating procedures for the silicon carbide and the outer pyrocarbon layers require knowledge of the detailed kinetics of the reaction processes in the gas phase and at the surfaces where the particles interact with the reactor walls. The intent of this project was to acquire detailed information on the reaction kinetics for the chemical vapor deposition (CVD) of carbon and silicon carbine on uranium fuel pellets, including the location of transition state structures, evaluation of the associated activation energies, and the use of these activation energies in the prediction of reaction rate constants. After the detailed reaction kinetics were determined, the reactions were implemented and tested in a computational fluid dynamics model, MFIX. The intention was to find a reduced mechanism set to reduce the computational time for a simulation, while still providing accurate results

  11. TNF-alpha-induced mitochondrial alterations in human T cells requires FADD and caspase-8 activation but not RIP and caspase-3 activation.

    Science.gov (United States)

    Shakibaei, Mehdi; Sung, Bokyung; Sethi, Gautam; Aggarwal, Bharat B

    2010-09-15

    Although much is known about how TNF-alpha induces apoptosis in the presence of inhibitors of protein synthesis, little is known about how it induces apoptosis without these inhibitors. In this report we investigated temporal sequence of events induced by TNF-alpha in the absence of protein synthesis. Regardless of whether we measured the effects by plasma membrane phosphotidylserine accumulation, by DNA strand breaks, or activation of caspases, significant changes were observed only between 12-24 h of TNF-alpha treatment. One of the earliest changes observed after TNF-alpha treatment was mitochondrial swelling at 10 min; followed by cytochrome c and Smac release at 10-30 min, and then heterochromatin clumping occurred at 60 min. While genetic deletion of receptor-interaction protein (RIP) had no effect on TNF-alpha-induced mitochondrial damage, deletion of Fas-associated death domain (FADD) abolished the TNF-induced mitochondrial swelling. Since pan-caspase inhibitor z-VAD-fmk abolished the TNF-alpha-induced mitochondrial changes, z-DEVD-fmk, an inhibitor of caspase-3 had no effect, suggesting that TNF-alpha-induced mitochondrial changes or cytochrome c and Smac release requires caspase-8 but not caspase-3 activation. Overall, our results indicated that mitochondrial changes are early events in TNF-alpha-induced apoptosis and that these mitochondrial changes require recruitment of FADD and caspase-8 activation, but not caspase-3 activation or RIP recruitment. PMID:20136500

  12. Activation cross-sections of deuteron induced nuclear reactions on gold up to 40 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Tarkanyi, F. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Ditroi, F., E-mail: ditroi@atomki.hu [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel (VUB), Brussels (Belgium); Takacs, S.; Kiraly, B. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Yamazaki, H.; Baba, M.; Mohammadi, A. [Cyclotron and Radioisotope Center (CYRIC), Tohoku University, Sendai (Japan); Ignatyuk, A.V. [Institute of Physics and Power Engineering (IPPE), Obninsk (Russian Federation)

    2011-06-15

    Cross-sections of deuteron induced nuclear reactions on gold were measured up to 40 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 {sup 197}Au(d,xn){sup 197m,197g,195m,195g}Hg and {sup 197}Au(d,x){sup 198g,196m,196g,195,194}Au nuclear reactions. The experimental data are analyzed and compared to literature and predictions of the ALICE-IPPE, EMPIRE and TALYS theoretical model codes. The application of the new cross-sections for accelerator technology, medical radioisotope production, thin layer activation and dose calculation is discussed.

  13. 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.

  14. 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.

  15. Sensitivity of (d,p) reactions to high n-p momenta and the consequences for nuclear spectroscopy studies

    CERN Document Server

    Bailey, G W; Tostevin, J A

    2016-01-01

    Theoretical models of low-energy (d,p) single-neutron transfer reactions are a crucial link between experimentation, nuclear structure and nuclear astrophysical studies. Whereas reaction models that use local optical potentials are insensitive to short-range physics in the deuteron, we show that including the inherent nonlocality of the nucleon-target interactions and realistic deuteron wave functions generates significant sensitivity to high n-p relative momenta and to the underlying nucleon-nucleon interaction. We quantify this effect upon the deuteron channel distorting potentials within the framework of the adiabatic deuteron breakup model. The implications for calculated (d,p) cross sections and spectroscopic information deduced from experiments are discussed.

  16. Investigation of the deuteron diffusion in single- and polycrystalline nickel absorbers by means of the nuclear reaction technique

    International Nuclear Information System (INIS)

    The isothermic diffusion (T = 254 K) of implanted deuterons in single- and polycristalline nickel absorbers is studied by means of the D(d,p)T nuclear reaction. At high doses the mobility of the implanted deuterons is drastically reduced, which is connected with the radiation damage caused by the implantation process itself. On the other hand at low doses the deuteron distributions change as predicted by the common diffusion law of Fick. The applied nuclear reaction technique permits the direct observation of ion distributions in an absorber and their changes by diffusion - without any influence of the surface conditions on the evaluation. The method can be applied successfully in the study of slowly changing ion distributions (small diffusion coefficients). (orig.)

  17. Measurement of nuclear reaction rates and spectral indices along the radius of fuel pellets from IPEN/MB-01 reactor

    International Nuclear Information System (INIS)

    This work presents the measurements of the nuclear reaction rates along the radial direction of the fuel pellet by irradiation and posterior gamma spectrometry of a thin slice of fuel pellet of UO2 with 4,3% enrichment. From its irradiation the rate of radioactive capture and fission have been measured as a function of the radius of the pellet disk using a HPGe detector. Lead collimators has been used for this purpose. Simulating the fuel pellet in the pin fuel of the IPEN/MB-01 reactor, a thin UO2 disk is used. This disk is inserted in the interior of a dismountable fuel rod. This fuel rod is then placed in the central position of the IPEN/MB-01 reactor core and irradiated during 1 hour under a neutron flux of around 9 x 108 n/cm2s. For gamma spectrometry 10 collimators with different diameters have been used, consequently, the nuclear reactions of radioactive capture that occurs in atoms of 238U and fissions that occur on both 235U and 238U are measured in function of 10 different region (diameter of collimator) of the fuel pellet disk. Corrections in the geometric efficiency due to introduction of collimators on HPGe detection system were estimated using photon transport of MCNP-4C code. Some calculated values of nuclear reaction rate of radioactive capture and fission along of the radial direction of the fuel pellet obtained by Monte Carlo methodology, using the MCNP-4C code, are presented and compared to the experimental data showing very good agreement. Besides nuclear reaction rates, the spectral indices 28ρ and 25δ have been obtained at each different radius of the fuel pellet disk. (author)

  18. Report on the IAEA consultants' meeting on the co-ordination of nuclear reaction data centres (technical aspects)

    International Nuclear Information System (INIS)

    This report summarizes the results of the IAEA Consultants' Meeting on the Co-ordination of Nuclear Reaction Data Centres (Technical Aspects), held at the IAEA Headquarters, Vienna, Austria, 28 to 30 May 2001. The meeting was attended by 16 participants from 10 co-operating data centres from six 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)

  19. Propagation of Cosmic Rays: Nuclear Physics in Cosmic-ray Studies

    Science.gov (United States)

    Moskalenko, Igor V.; Strong, Andrew W.; Mashnik, Stepan G.

    2004-01-01

    The nuclei fraction in cosmic rays (CR) far exceeds the fraction of other CR species, such as antiprotons, electrons, and positrons. Thus the majority of information obtained from CR studies is based on interpretation of isotopic abundances using CR propagation models where the nuclear data and isotopic production cross sections in p- and alpha-induced reactions are the key elements. This paper presents an introduction to the astrophysics of CR and diffuse gamma-rays and dimsses some of the puzzles that have emerged recently due to more precise data and improved propagation models. Merging with cosmology and particle physics, astrophysics of CR has become a very dynamic field with a large potential of breakthrough and discoveries in the near fume. Exploiting the data collected by the CR experiments to the fullest requires accurate nuclear cross sections.

  20. Financing new nuclear capacity: Will the ''nuclear renaissance'' Be a Self-Sustaining reaction?

    Energy Technology Data Exchange (ETDEWEB)

    George, Glenn R.

    2007-04-15

    Although EPAct offers a number of benefits for new nuclear capacity, a host of gaps remain, from the timing of capital formation to the residual risk that the actual cost of the first few plants will significantly exceed estimates. Securitization and related financial techniques could play a role in turning revenue streams into lumps of capital. (author)

  1. An efficient nonclassical quadrature for the calculation of nonresonant nuclear fusion reaction rate coefficients from cross section data

    Science.gov (United States)

    Shizgal, Bernie D.

    2016-08-01

    Nonclassical quadratures based on a new set of half-range polynomials, Tn(x) , orthogonal with respect to w(x) =e - x - b /√{ x } for x ∈ [ 0 , ∞) are employed in the efficient calculation of the nuclear fusion reaction rate coefficients from cross section data. The parameter b = B /√{kB T } in the weight function is temperature dependent and B is the Gamow factor. The polynomials Tn(x) satisfy a three term recurrence relation defined by two sets of recurrence coefficients, αn and βn. These recurrence coefficients define in turn the tridiagonal Jacobi matrix whose eigenvalues are the quadrature points and the weights are calculated from the first components of the eigenfunctions. For nonresonant nuclear reactions for which the astrophysical function can be expressed as a lower order polynomial in the relative energy, the convergence of the thermal average of the reactive cross section with this nonclassical quadrature is extremely rapid requiring in many cases 2-4 quadrature points. The results are compared with other libraries of nuclear reaction rate coefficient data reported in the literature.

  2. Transmutation of nuclear wastes using photonuclear reactions triggered by Compton backscattering photons at the Shanghai laser electrongamma source

    Institute of Scientific and Technical Information of China (English)

    CHEN Jin-Gen; YUAN Ren-Yong; XU Jia-Qiang; YAN Zhe; FAN Gong-Tao; SHEN Wen-Qing; XU Wang; WANG Hong-Wei; GUO Wei; MA Yu-Gang; CAI Xiang-Zhou; LU Guang-Cheng; XU Yi; PAN Qiang-Yan

    2008-01-01

    Based on the facility of the Shanghai Laser Electron Gamma Source (SLEGS),the transmutation for nuclear wastes such as 137Cs and 129I is investigated.It is found that nuclear waste can be transmuted efficiently via photonuclear reaction triggered by gamma photons generated from Compton backscattering between CO2 laser photons and 3.5 GeV electrons.The nuclear activities of 137Cs and 129I are evaluated and compared with the results of transmutation triggered by bremsstrahlung gamma photons driven by ultra intense laser.Due to the better character of gamma photon spectrum as well as the high brightness of gamma photons,the transmutation rate of Compton backscattering method is much higher than that of the bremsstrahlung method.

  3. Characterization of specific nuclear reaction channels by deconvolution in the energy space of the total nuclear cross-section of protons - applications to proton therapy and technical problems

    CERN Document Server

    Ulmer, W

    2016-01-01

    The total nuclear cross-section Qtot(E) resulting from the interaction of protons with nuclei is decomposed in 3 different contributions: 1. elastic scatter at the complete nucleus, which adopts a part of the proton kinetic energy; 2. inelastic scatter at a nucleus, which changes its quantum numbers by vibrations, rotations, transition to highly excited states; 3. proper nuclear reactions with change of the mass and/or charge number. Then different particles leave the hit nucleus (neutrons, protons, etc.), which is now referred to as 'heavy recoil' nucleus. The scatter parts of Qtot(E) according to points 1 and 2 can be removed by a deconvolution acting at Qtot(E) in the energy space. The typical nuclear reaction channels are mainly characterized by resonances of a reduced cross-section function Qred(E). The procedure is applied to cross-sections of therapeutic protons and also to Cs55137 as an example with technical relevance (transmutations with the goal to drastically reduce its half-time).

  4. New activation cross section data on longer lived radio-nuclei produced in proton induced nuclear reaction on zirconium

    CERN Document Server

    Tárkányi, F; Takács, S; Hermanne, A; Al-Abyad, M; Yamazaki, H; Baba, M; Mohammadi, M A

    2016-01-01

    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)$^{178-178m}$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.

  5. Transforming growth factor-beta suppresses tumor necrosis factor alpha-induced matrix metalloproteinase-9 expression in monocytes.

    Science.gov (United States)

    Vaday, G G; Schor, H; Rahat, M A; Lahat, N; Lider, O

    2001-04-01

    The inflammatory response is marked by the release of several cytokines with multiple roles in regulating leukocyte activities, including the secretion of matrix metalloproteinases (MMPs). Although the effects of individual cytokines on monocyte MMP expression have been studied extensively, few studies have examined the influence of combinations of cytokines, which are likely present at inflammatory sites. Herein, we report our investigation of the combinatorial effects of tumor necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta on MMP-9 synthesis. We found that TGF-beta suppressed TNF-alpha-induced MMP-9 secretion by MonoMac-6 monocytic cells in a dose-dependent manner, with a maximal effect of TGF-beta observed at 1 ng/ml. Such suppression was likely regulated at the pretranslational level, because steady-state mRNA levels of TNF-alpha-induced MMP-9 were reduced by TGF-beta, and pulse-chase radiolabeling also showed a decrease in new MMP-9 protein synthesis. The suppressive effects of TGF-beta were time dependent, because short exposures to TNF-alpha before TGF-beta or simultaneous exposure to both cytokines efficiently reduced MMP-9 secretion. Expression of the tissue inhibitor of metalloproteinases (TIMP)-1 and TNF-alpha receptors was unaffected by either cytokine individually or in combination. Affinity binding with radiolabeled TGF-beta demonstrated that levels of TGF-beta receptors were not increased after preincubation with TGF-beta. Suppression of TNFalpha-induced MMP-9 secretion by TGF-beta correlated with a reduction in prostaglandin E2 (PGE2) secretion. Furthermore, the effect of TGF-beta or indomethacin on blockage of TNF-alpha-stimulated MMP-9 production was reversed by the addition of either exogenous PGE2 or the cyclic AMP (cAMP) analogue Bt2cAMP. Thus, we concluded that TGF-beta acts as a potent suppressor of TNF-alpha-induced monocyte MMP-9 synthesis via a PGE2- and cAMP-dependent mechanism. These results suggest that various

  6. 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

  7. Synergistic effect of vasoactive intestinal peptides on TNF-alpha-induced IL-6 synthesis in osteoblasts: amplification of p44/p42 MAP kinase activation.

    Science.gov (United States)

    Natsume, Hideo; Tokuda, Haruhiko; Mizutani, Jun; Adachi, Seiji; Matsushima-Nishiwaki, Rie; Minamitani, Chiho; Kato, Kenji; Kozawa, Osamu; Otsuka, Takanobu

    2010-05-01

    We previously showed that tumor necrosis factor-alpha (TNF-alpha) stimulates synthesis of interleukin-6 (IL-6), a potent bone resorptive agent, via p44/p42 mitogen-activated protein (MAP) kinase and phosphatidylinositol 3-kinase/Akt in osteoblast-like MC3T3-E1 cells. In the present study, we investigated the effect of vasoactive intestinal peptide (VIP) on TNF-alpha-induced IL-6 synthesis in these cells. VIP, which by itself slightly stimulated IL-6 synthesis, synergistically enhanced the TNF-alpha-induced IL-6 synthesis in MC3T3-E1 cells. The synergistic effect of VIP on the TNF-alpha-induced IL-6 synthesis was concentration-dependent in the range between 1 and 70 nM. We previously reported that VIP stimulated cAMP production in MC3T3-E1 cells. Forskolin, a direct activator of adenylyl cyclase, or 8-bromoadenosine-3',5'-cyclic monophosphate (8bromo-cAMP), a plasma membrane-permeable cAMP analogue, markedly enhanced the TNF-alpha-induced IL-6 synthesis as well as VIP. VIP markedly up-regulated the TNF-alpha-induced p44/p42 MAP kinase phosphorylation. The Akt phosphorylation stimulated by TNF-alpha was only slightly affected by VIP. PD98059, a specific inhibitor of MEK1/2, significantly suppressed the enhancement of TNF-alpha-induced IL-6 synthesis by VIP. The synergistic effect of a combination of VIP and TNF-alpha on the phosphorylation of p44/p42 MAP kinase was diminished by H-89, an inhibitor of cAMP-dependent protein kinase. These results strongly suggest that VIP synergistically enhances TNF-alpha-stimulated IL-6 synthesis via up-regulating p44/p42 MAP kinase through the adenylyl cyclase-cAMP system in osteoblasts.

  8. TORUS: Theory of Reactions for Unstable iSotopes.Topical Collaboration for Nuclear Theory Project. Period: June 1, 2010 - May 31, 2015

    Energy Technology Data Exchange (ETDEWEB)

    Arbanas, Goran [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Elster, Charlotte [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Escher, Jutta [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Nunes, Filomena [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thompson, Ian [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-08-28

    The work of this collaboration during its existence is summarized. The mission of the TORUS Topical Collaboration was to develop new methods that advance nuclear reaction theory for unstable isotopes by using three-body techniques to improve direct reaction calculations. This multi-institution collaborative effort was and remains directly relevant to three areas of interest: the properties of nuclei far from stability, microscopic studies of nuclear input parameters for astrophysics, and microscopic nuclear reaction theory. The TORUS project focused on understanding the details of (d,p) reactions for neutron transfer to heavier nuclei. The bulk of the work fell into three areas: coupled channel theory, modeling (d,p) reactions with a Faddeev-AGS approach, and capture reactions.

  9. Fragment Produced by Nuclear Reaction of Heavy Ions Interacted with Tissue-equivalent Biological Material

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In heavy ion therapy and radiation biological effects the nuclear fragments from the heavy ion collisions may cause a significant alteration of the radiation field. Nuclear collision between beam particles and tissue nuclei along the penetration path of high-energy ions in tissue or biological-equivalent material causes a loss

  10. Social and breed effects on the expression of a PGF2alpha induced oestrus in beef cows.

    Science.gov (United States)

    Landaeta-Hernández, A J; Palomares-Naveda, R; Soto-Castillo, G; Atencio, A; Chase, C C; Chenoweth, P J

    2004-10-01

    Social organization and breed effects following PGF2alpha were studied in mature Angus, Brahman and Senepol cows allocated into two groups (each A = 5, B = 5 and S = 5). Variables including interval to oestrus onset (IEO), oestrous duration (DE), total mounts received (TMR), and oestrous intensity (IE) were derived via HeatWatch. Breed-type influenced IEO (B = 42.6 +/- 6.7 h; S = 54.6 +/- 6.0 h; and A = 27.8 +/- 5.8 h; p 0.05). Dominant cows tended (p < 0.10) to have less TMR (3.2 +/- 0.7 mounts) than subordinate (4.1 +/- 0.4 mounts) and intermediate (4.7 +/- 0.6 mounts) throughout, especially 3-6 h after oestrus onset (p < 0.07). Breed and social order both influence PGF2alpha-induced oestrus behaviour. PMID:15367263

  11. Reactions of charged and neutral recoil particles following nuclear transformations. Progress report No. 13

    International Nuclear Information System (INIS)

    Research is reported on: caging and solvent effects in hot 38Cl substitution reactions in chlorinated hydrocarbons (dichlorobenzene), excitation labelling of organic compounds using 80Br, reactions of energetic tritium with graphite and SiC surfaces, and micellar systems and microemulsions studied by positron annihilation

  12. Status of experimental data of proton-induced reactions for intermediate-energy nuclear data evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yukinobu; Kawano, Toshihiko [Kyushu Univ., Fukuoka (Japan); Yamano, Naoki; Fukahori, Tokio

    1998-11-01

    The present status of experimental data of proton-induced reactions is reviewed, with particular attention to total reaction cross section, elastic and inelastic scattering cross section, double-differential particle production cross section, isotope production cross section, and activation cross section. (author)

  13. EXCITATION OF NUCLEAR HOLE STATES BY THE (e,e'p) REACTION

    OpenAIRE

    Lapikás, L.; De Witt Huberts, P.K.A.

    1984-01-01

    Various theoretical and experimental aspects of the (e, e'p) reaction are discussed. Performance of the NIKHEF-K apparatus is described and illustrated with spectral functions for the (e,e'p) reaction on 12C, 27Al and 51V nuclei.

  14. Studies of nuclear reactions relevant to stellar or Big-Bang Nucleosynthesis using ICF plasmas at OMEGA

    Science.gov (United States)

    Zylstra, Alex; Herrmann, Hans; Kim, Yongho; Hale, Gerry; Paris, Mark; McEvoy, Aaron; Gatu Johnson, Maria; Frenje, Johan; Li, Chikang; Seguin, Fredrick; Sio, Hong; Petrasso, Richard; McNabb, Dennis; Sayre, Dan; Pino, Jesse; Brune, Carl; Bacher, Andy; Forrest, Chad; Glebov, Vladimir; Stoeckl, Christian; Janezic, Roger; Sangster, Craig

    2015-11-01

    The 3He+3He, T+3He, and p +D reactions directly relevant to Stellar or Big-Bang Nucleosynthesis (BBN) have been studied at the OMEGA laser facility using high-temperature low-density `exploding pusher' implosions. The advantage of using these plasmas is that they better mimic astrophysical systems than cold-target accelerator experiments. Measured proton spectra from the 3He3He reaction are used to constrain nuclear R-matrix modeling. The resulting T+3He gamma-ray data rule out an anomalously-high 6Li production during the Big Bang as an explanation to the high observed values in metal poor first generation stars. The proton spectrum from the T+3He reaction is also being used to constrain the R-matrix model. Recent experiments have probed the p +D reaction for the first time in a plasma; this reaction is relevant to energy production in protostars, brown dwarfs and at higher CM energies to BBN. This work was partially supported by the US DOE, NLUF, LLE, and GA.

  15. Initiation of nuclear reactions under laser irradiation of Au nanoparticles in the aqueous solution of Uranium salt

    CERN Document Server

    Simakin, A V

    2010-01-01

    Laser exposure of suspension of either gold or palladium nanoparticles in aqueous solutions of UO2Cl2 of natural isotope abundance was experimentally studied. Picosecond Nd:YAG lasers at peak power from 1011 to 1013 W/cm2 at the wavelength of 1064 and 355 nm were used as well as a visible-range Cu vapor laser at peak power of 1010 W/cm2. The composition of colloidal solutions before and after laser exposure was analyzed using atomic absorption and gamma spectroscopy between 0.06 and 1 MeV range of photon energy. A real-time gamma-spectroscopy was used to characterize the kinetics of nuclear reactions during laser exposure. It was found that laser exposure initiated nuclear reactions involving both 238U and 235U nuclei via different channels in H2O and D2O. The influence of saturation of both the liquid and nanoparticles by gaseous H2 and D2 on the kinetics of nuclear transformations was found. Possible mechanisms of observed processes are discussed.

  16. 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.

  17. 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.

  18. Calculations of Maxwellian-averaged Cross Sections and Astrophysical Reaction Rates Using the ENDF/B-VII.0, JEFF-3.1, JENDL-3.3 and ENDF/B-VI.8 Evaluated Nuclear Reaction Data Libraries

    OpenAIRE

    Pritychenko, B.; Mughaghab, S. F.; Sonzogni, A. A.

    2009-01-01

    We calculated the Maxwellian-averaged cross sections (MACS) and astrophysical reaction rates of the stellar nucleosynthesis reactions (n,$\\gamma$), (n,fission), (n,p), (n,$\\alpha$) and (n,2n) using the ENDF/B-VII.0-, JEFF-3.1-, JENDL-3.3-, and ENDF/B-VI.8-evaluated nuclear-data libraries. Four major nuclear reaction libraries were processed under the same conditions for Maxwellian temperatures ({\\it kT}) ranging from 1 keV to 1 MeV. We compare our current calculations of the {\\it s}-process n...

  19. Nuclear tracks in PADC induced by neutron, heavy ion and energetic fragments formed in the reaction {sup 54}Cr + {sup 208}Pb, at 320 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Barbui, M. [INFN Laboratori Nazionali di Legnaro, I-35020 Legnaro (Pd) (Italy); Fabris, D.; Moretto, S.; Nebbia, G. [Dipartimento di Fisica and Sezione INFN Padova, I-35131 Padova (Italy); Nemeth, P. [Departamento de Fisica, Universidad Simon Bolivar, Caracas 1080A (Venezuela, Bolivarian Republic of); Palfalvi, J. [Atomic Energy Research Institute P.O. Box 49, H-1525 Budapest (Hungary); Pesente, S. [Dipartimento di Fisica and Sezione INFN Padova, I-35131 Padova (Italy); Prete, G. [INFN Laboratori Nazionali di Legnaro, I-35020 Legnaro (Pd) (Italy); Sajo-Bohus, L., E-mail: sajobhus@gmail.co [Departamento de Fisica, Universidad Simon Bolivar, Caracas 1080A (Venezuela, Bolivarian Republic of); Viesti, G. [Dipartimento di Fisica and Sezione INFN Padova, I-35131 Padova (Italy)

    2009-10-15

    Passive nuclear track detectors in the study of multi fragmentation and compound nucleus fission in the fusion reaction {sup 54}Cr + {sup 208}Pb, leading to composite systems with Z = 106 is given. Results indicate that mostly nuclear tracks are related to fragments with low atomic number and less than 11% to beam like particles in opposition to the expected distribution.

  20. Nuclear tracks in PADC induced by neutron, heavy ion and energetic fragments formed in the reaction 54Cr + 208Pb, at 320 MeV

    International Nuclear Information System (INIS)

    Passive nuclear track detectors in the study of multi fragmentation and compound nucleus fission in the fusion reaction 54Cr + 208Pb, leading to composite systems with Z = 106 is given. Results indicate that mostly nuclear tracks are related to fragments with low atomic number and less than 11% to beam like particles in opposition to the expected distribution.

  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. Measurements of neutron-induced reactions in inverse kinematics and applications to nuclear astrophysics

    OpenAIRE

    Reifarth René; Litvinov Yuri A.; Endres Anne; Göbel Kathrin; Heftrich Tanja; Glorius Jan; Koloczek Alexander; Sonnabend Kerstin; Travaglio Claudia; Weigand Mario

    2015-01-01

    Neutron capture cross sections of unstable isotopes are important for neutron-induced nucleosynthesis as well as for technological applications. A combination of a radioactive beam facility, an ion storage ring and a high flux reactor would allow a direct measurement of neutron induced reactions over a wide energy range on isotopes with half lives down to minutes. The idea is to measure neutron-induced reactions on radioactive ions in inverse kinematics. This means, the radioactive ions will ...

  3. Disassembly of hot nuclear matter formed in Au-induced reactions near the Fermi energy

    Energy Technology Data Exchange (ETDEWEB)

    Delis, D.N.

    1993-09-01

    Complex fragment emission has been studied in the 60 MeV/A {sup 197}Au + {sup 12}C, {sup 27}Al, {sup 51}V, {sup nat}Cu, and {sup 197}Au reactions. Velocity spectra, angular distributions and cross sections have been constructed for each target from the inclusive data. Coincidence data including 2-, 3-, 4-, and 5-fold events have also been examined. Furthermore neutron multiplicity distributions have been obtained for the above reactions by utilizing a novel neutron calorimetric approach.

  4. Nuclear stopping for heavy-ion induced reactions in the Fermi energy range : from 1-Body to 2-Body dissipation

    Directory of Open Access Journals (Sweden)

    Lopez O.

    2014-03-01

    Full Text Available We study the stopping in heavy-ion induced reactions around the Fermi energy in central collisions. The stopping is minimal around the Fermi energy and corresponds to the crossover between the Mean-Field and the nucleonic regimes. This is attributed to the change in the energy dissipation going from 1-body (Mean-Field to 2-body (nucleonnucleon collisions dissipation. For this latter, a connection to in-medium transport properties of nuclear matter is proposed and comprehensive values of the nucleon mean free path and nucleon-nucleon cross section are extracted.

  5. NUMEN Project @ LNS : Heavy ions double charge exchange reactions towards the 0νββ nuclear matrix element determination

    Energy Technology Data Exchange (ETDEWEB)

    Agodi, C., E-mail: agodi@lns.infn.it; Calabretta, L.; Calanna, A.; Carbone, D.; Cavallaro, M.; Colonna, M.; Cuttone, G.; Finocchiaro, P.; Pandola, L.; Rifuggiato, D.; Tudisco, S. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Cappuzzello, F.; Greco, V. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy); Bonanno, D. L.; Bongiovanni, D. G.; Longhitano, F. [INFN - Sezione di Catania, Catania (Italy); Branchina, V. [Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy); Foti, A.; Lo Presti, D. [Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy); INFN - Sezione di Catania, Catania (Italy); Lanzalone, G. [Università di Enna, Enna (Italy); and others

    2015-10-28

    In the NUMEN Project it is proposed an innovative technique to access the nuclear matrix elements entering in the expression of the life-time of the neutrinoless double beta decay, using relevant cross sections of double charge exchange reactions. A key aspect is the use of MAGNEX large acceptance magnetic spectrometer, for the detection of the ejectiles, and of the INFN Laboratori Nazionali del Sud (LNS) K800 Superconducting Cyclotron (CS), for the acceleration of the required high resolution and low emittance heavy-ion beams.

  6. Computerized control system of gaseous mixture preparation complex for experimental study of muon catalysis of nuclear synthesis reaction

    International Nuclear Information System (INIS)

    The computerized system for controlling and monitoring the gaseous mixture preparation complex Triton intended for experimental studies on the muon catalysis of the synthesis nuclear reactions in the ternary mixtures of the H/D/T hydrogen isotopes within the wide range of temperatures and pressures is described. The system provides also for controlling and monitoring the target parameters, the gaseous mixture composition control and dosimetric control. Good performance characteristics, high reliability and possibility of fast adaptation of the system for solving new tasks are demonstrated in the course of multiple physical experiments

  7. Report on the IAEA technical meeting on co-ordination of the network of nuclear reaction data centres

    International Nuclear Information System (INIS)

    Results of the IAEA Technical Meeting on the Co-ordination of the Network of Nuclear Reaction Data Centres held at the IAEA Headquarters, Vienna, Austria, 17 to 19 June 2003, are summarised in this report. The meeting was attended by 14 participants from 9 cooperating data centres of five member states and two International Organizations. A meeting summary, the conclusions and actions, progress and status reports of the participating data centres, and working papers considered at the meeting, are given in the relevant sections. (author)

  8. OSCAR, a code for the calculation of the yield of radioisotopes produced by charged-particle induced nuclear reactions

    International Nuclear Information System (INIS)

    A computer code OSCAR, operated on a main frame computer was developed for the calculation of the yield of radioisotopes produced by charged-particle induced nuclear reactions. The excitation functions required for calculating the yield were evaluated by means of an empirical rule which we developed on the basis of a systematics derived from a number of experimental data reported in the literature. The rule is valid for light ion (Z ≤ 2)-induced reactions followed by neutron emission processes. Other excitation functions are also obtainable from the data file in OSCAR. In addition, the code possesses functions useful for the calculation of the stopping power and range. The energy loss and the distribution of recoil products in stacked targets are also provided as options. The formalism, structure, and direction for the usage of the code are described together with the explanation of the functions of some routines. (author)

  9. Solid-state detectors for measurement of dE/dx and total energy in nuclear reactions at cyclotron energies

    International Nuclear Information System (INIS)

    Surface-barrier p-n detectors with thick sensitive regions for measuring the total energy of the reactions initiated by the Argonne 60-in cyclotron, and physically thin detectors to identify the nature of particles by their rate of energy loss were developed by the authors. The paper describes the main design elements of these detectors and the principal performance data of the solid-state counter systems used. Detectors of 1 cm2 sensitive area (0.5 μA leakage current at 400-V back bias in a typical case) are also described. The very satisfactory resolution of the Argonne detectors allows accurate measurements to be made in nuclear reactions at cyclotron energy. (author)

  10. Probing the nuclear equation of state by heavy-ion reactions and neutron star properties

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, P.K.; Cassing, W.; Thoma, M.H. [Inst. fuer Theoretische Physik, Univ. Giessen (Germany)

    1998-06-01

    We discuss the nuclear equation of state (EOS) using a non-linear relativistic transport model. From the baryon flow for Ni + Ni as well as Au + Au systems we find that the strength of the vector potential has to be reduced at high density or at high relative momenta to describe the experimental flow data at 1-2 A GeV. We use the same dynamical model to calculate the nuclear EOS and then employ this EOS to neutron star structure calculations. We consider the core of the neutron star to be composed of neutrons with an admixture of protons, electrons, muons, sigmas and lambdas at zero temperature. We find that the nuclear equation of state is softer at high densities and hence the maximum mass and the radius of the neutron star are in the observable range of M {proportional_to} 1.7 M{sub s}un and R = 8 km, respectively. (orig.)

  11. 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

  12. Neutron-proton bremsstrahlung from intermediate energy heavy-ion reactions as a probe of the nuclear symmetry energy?

    International Nuclear Information System (INIS)

    Hard photons from neutron-proton bremsstrahlung in intermediate energy heavy-ion reactions are examined as a potential probe of the nuclear symmetry energy within a transport model. Effects of the symmetry energy on the yields and spectra of hard photons are found to be generally smaller than those due to the currently existing uncertainties of both the in-medium nucleon-nucleon cross sections and the photon production probability in the elementary process pn→pnγ. Very interestingly, nevertheless, the ratio of hard photon spectra R1/2(γ) from two reactions using isotopes of the same element is not only approximately independent of these uncertainties but also quite sensitive to the symmetry energy. For the head-on reactions of 132Sn + 124Sn and 112Sn + 112Sn at Ebeam/A=50 MeV, for example, the R1/2(γ) displays a rise up to 15% when the symmetry energy is reduced by about 20% at ρ=1.3ρ0 which is the maximum density reached in these reactions

  13. Experimental study to explore the 8Be-induced nuclear reaction via the Trojan horse method

    Science.gov (United States)

    Wen, Qun-Gang; Li, Cheng-Bo; Zhou, Shu-Hua; Irgaziev, Bakhadir; Fu, Yuan-Yong; Spitaleri, Claudio; La Cognata, Marco; Zhou, Jing; Meng, Qiu-Ying; Lamia, Livio; Lattuada, Marcello

    2016-03-01

    To explore a possible indirect method for 8Be induced astrophysical reactions, the 8Be=(8Be+n ) cluster structure has been studied via the Trojan horse method. For the first time a 8Be nucleus having an ultrashort lifetime is studied by the Trojan horse method and a 9Be nucleus in the ground state is used for this purpose. The 9Be nucleus is assumed to have a (8Be+n ) cluster structure and used as a Trojan horse nucleus. The 8Be nucleus acts as a participant, while the neutron is a spectator to the virtual 8Be+d →α +6Li reaction via the 3-body reaction 8Be+d →α +6Li+n . The experimental neutron momentum distribution inside 9Be has been reconstructed. The agreement between the experimental momentum distribution and the theoretical one indicates that a (8Be+n ) cluster structure inside 9Be is very likely. Therefore, the experimental study of 8Be induced reactions, for example, the measurement of the 8Be+α →12C reaction proceeding through the Hoyle state, is possible.

  14. Study of the nuclear reaction relevant to primordial nucleosynthesis: 8Li (α,n)11B

    International Nuclear Information System (INIS)

    A critical reaction in predicting abundances of 11B and heavier nuclides in the inhomogeneous models (IMs) is 8Li(α,n)11B, as 11B is the nuclide through which most heavier nuclides must pass, and that reaction apparently regulates the dominant pathway by which 11B is made in the IMs. The obvious complication in observing this reaction is the 840.3 ms half life of 8Li. A recent measurement of the inverse reaction 11B(n,α)8Li gives the ground state-ground state cross section for 8Li(α,n)11B. However, several 11B excited to be populated in 8Li(α,n)11B, so inference of the cross section of interest from measurement of the inverse reaction may underestimate the actual value by a large factor. Thus we have measured the cross section for 8Li(α,n)11B directly, using an 8Li radioactive beam and a novel detection technique. The results of that experiment are reported here. 23 refs., 4 figs

  15. beta-Naphthoflavone protects from peritonitis by reducing TNF-alpha-induced endothelial cell activation.

    Science.gov (United States)

    Hsu, Sheng-Yao; Liou, Je-Wen; Cheng, Tsung-Lin; Peng, Shih-Yi; Lin, Chi-Chen; Chu, Yuan-Yuan; Luo, Wei-Cheng; Huang, Zheng-Kai; Jiang, Shinn-Jong

    2015-12-01

    β-Naphthoflavone (β-NF), a ligand of the aryl hydrocarbon receptor, has been shown to possess anti-oxidative properties. We investigated the anti-oxidative and anti-inflammatory potential of β-NF in human microvascular endothelial cells treated with tumor necrosis factor-alpha (TNF-α). Pretreatment with β-NF significantly inhibited TNF-α-induced intracellular reactive oxygen species, translocation of p67(phox), and TNF-α-induced monocyte binding and transmigration. In addition, β-NF significantly inhibited TNF-α-induced ICAM-1 and VCAM-1 expression. The mRNA expression levels of the inflammatory cytokines TNF-α and IL-6 were reduced by β-NF, as was the infiltration of white blood cells, in a peritonitis model. The inhibition of adhesion molecules was associated with suppressed nuclear translocation of NF-κB p65 and Akt, and suppressed phosphorylation of ERK1/2 and p38. The translocation of Egr-1, a downstream transcription factor involved in the MEK-ERK signaling pathway, was suppressed by β-NF treatment. Our findings show that β-NF inhibits TNF-α-induced NF-kB and ERK1/2 activation and ROS generation, thereby suppressing the expression of adhesion molecules. This results in reduced adhesion and transmigration of leukocytes in vitro and prevents the infiltration of leukocytes in a peritonitis model. Our findings also suggest that β-NF might prevent TNF-α-induced inflammation.

  16. Heavy flavours production in quark-gluon plasma formed in high energy nuclear reactions

    Science.gov (United States)

    Kloskinski, J.

    1985-01-01

    Results on compression and temperatures of nuclear fireballs and on relative yield of strange and charmed hadrons are given . The results show that temperatures above 300 MeV and large compressions are unlikely achieved in average heavy ion collision. In consequence, thermal production of charm is low. Strange particle production is, however, substantial and indicates clear temperature - threshold behavior.

  17. ECOS-LINCE : A high-intensity heavy-ion facility for nuclear structure and reactions

    NARCIS (Netherlands)

    Martel, I.; Bontoiu, C.; Orduz, A.K.; Acosta, L.; Barrios, E.; Bergillos, A.; Carrasco, R.; Dueñas, J.A.; Gordo-Yañez, D.; Peregrin, A.; Pinto-Gomez, A.R.; Prieto-Thomas, J.A.; Ruiz-Pomares, M.J.; Sanchez-Benitez, A.M.; Junquera, T.; Sanchez Segovia, J.; Ostroumov, P.N.; Villari, A.C.C.; Harakeh, M.N.

    2016-01-01

    During the last years, the ECOS working group has been considering the construction of a new high-intensity accelerator of stable ion beams for the next Long-Range Plan of the nuclear physics community in Europe. The new facility (LINCE) will be a multi-user facility dedicated to ECOS science: funda

  18. Search for AN Eta-Nuclear Bound State in the Double Charge Exchange Reaction OXYGEN-18

    Science.gov (United States)

    Johnson, John Doeppers

    1992-01-01

    Recent calculations have predicted that a bound state between an eta and a nucleus may occur as an intermediate state in pion double charge exchange (DCX). The existence of such a mesic nucleus would lead to a resonance-like structure in the DCX excitation function at fixed momentum transfer. LAMPF Experiment 1140 searched for an eta-nucleus bound state in the DCX reaction ^{18}O(pi ^{+}, pi^ {-})^{18}Ne(DIAS). An excitation function for this reaction was measured for energies ranging from 350 to 440 MeV and for momentum transfers of q = 0, 105 and 210 MeV/c. The calculated cross sections agree favorably with previously published data. Theoretical calculations predict that a resonance structure will be evidenced by an enhanced cross section at the eta production threshold for this reaction. The measured excitation function has found some evidence of structure in this region.

  19. The Trojan Horse method for nuclear astrophysics: Recent results for direct reactions

    Energy Technology Data Exchange (ETDEWEB)

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

    The Trojan Horse method is a powerful indirect technique to determine the astrophysical factor for binary rearrangement processes A+x→b+B at astrophysical energies by measuring the cross section for the Trojan Horse (TH) reaction A+a→B+b+s in quasi free kinematics. The Trojan Horse Method has been successfully applied to many reactions of astrophysical interest, both direct and resonant. In this paper, we will focus on direct sub-processes. The theory of the THM for direct binary reactions will be shortly presented based on a few-body approach that takes into account the off-energy-shell effects and initial and final state interactions. Examples of recent results will be presented to demonstrate how THM works experimentally.

  20. The Trojan Horse method for nuclear astrophysics: Recent results for direct reactions

    Science.gov (United States)

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

    2014-05-01

    The Trojan Horse method is a powerful indirect technique to determine the astrophysical factor for binary rearrangement processes A+x→b+B at astrophysical energies by measuring the cross section for the Trojan Horse (TH) reaction A+a→B+b+s in quasi free kinematics. The Trojan Horse Method has been successfully applied to many reactions of astrophysical interest, both direct and resonant. In this paper, we will focus on direct sub-processes. The theory of the THM for direct binary reactions will be shortly presented based on a few-body approach that takes into account the off-energy-shell effects and initial and final state interactions. Examples of recent results will be presented to demonstrate how THM works experimentally.