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Sample records for reactions nuclear collisions

  1. From nuclear reactions to liquid-drop collisions

    International Nuclear Information System (INIS)

    Menchaca R, A.; Huidobro, F.; Martinez D, A.; Michaelian, K.; Perez, A.; Rodriguez, V.; Carjan, N.

    1997-01-01

    A review of the experimental and theoretical situation in coalescence and fragmentation studies of binary liquid-drop collisions is given, putting in perspective our own contributions, which include experiments with mercury and oil drops and the application of a nuclear reaction model, specifically modified by us for the macroscopic case. (Author)

  2. Final stage of high energy hadron-nucleus nuclear collision reactions

    International Nuclear Information System (INIS)

    Strugal'ski, Z.; Jedrzejec, H.; Strugalska-Gola, E.; Mulas, E.

    1996-01-01

    The final or 'slow' stage of the hadron-nucleus collision reactions at high energy is considered on the basis of the collision mechanism prompted experimentally. The transmutation process of the damaged target nucleus into nucleons and stable nuclear fragments is discussed. Relations between intensities or multiplicities n p of the emitted fast protons and the mean intensities or multiplicities b > of the evaporated nucleons and nuclear fragments are presented. 14 refs

  3. The mechanisms of the hadron-nucleus collision processes and of the hadron-nucleus collision induced nuclear reactions - in the light of experimental data

    International Nuclear Information System (INIS)

    Strugalski, Z.; Strugalska-Gola, E.

    1997-01-01

    The mechanisms of the hadron-nucleus collision processes and of the hadron-nucleus collision induced nuclear reactions are described - as experimentally based. The target nuclei are damaged definitely and locally in the collisions and the configurations of the nucleons in them became instable. The configuration must transit into stable stages of the nuclear transition reaction products. The difference between the initial internal energy of the unstable residual nucleus and the total final energy of the stable products of the nuclear transition reaction may be released in some cases

  4. Proceedings of the 2nd joint seminar on atomic collisions and heavy ion induced nuclear reactions

    International Nuclear Information System (INIS)

    Harada, Kichinosuke; Ozawa, Kunio; Kamitsubo, H.; Nomura, T.; Awaya, Y.; Watanabe, T.

    1982-11-01

    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)

  5. Relativistic nuclear collisions: theory

    International Nuclear Information System (INIS)

    Gyulassy, M.

    1980-07-01

    Some of the recent theoretical developments in relativistic (0.5 to 2.0-GeV/nucleon) nuclear collisions are reviewed. The statistical model, hydrodynamic model, classical equation of motion calculations, billiard ball dynamics, and intranuclear cascade models are discussed in detail. Inclusive proton and pion spectra are analyzed for a variety of reactions. Particular attention is focused on how the complex interplay of the basic reaction mechanism hinders attempts to deduce the nuclear matter equation of state from data. 102 references, 19 figures

  6. Effect of free-particle collisions in high energy proton and pion-induced nuclear reactions

    International Nuclear Information System (INIS)

    Jacob, N.P. Jr.

    1975-07-01

    The effect of free-particle collisions in simple ''knockout'' reactions of the form (a,aN) and in more complex nuclear reactions of the form (a,X) was investigated by using protons and pions. Cross sections for the 48 Ti(p,2p) 47 Sc and the 74 Ge(p,2p) 73 Ga reactions were measured from 0.3 to 4.6 GeV incident energy. The results indicate a rise in (p,2p) cross section for each reaction of about (25 +- 3) percent between the energies 0.3 and 1.0 GeV, and are correlated to a large increase in the total free-particle pp scattering cross sections over the same energy region. Results are compared to previous (p,2p) excitation functions in the GeV energy region and to (p,2p) cross section calculations based on a Monte Carlo intranuclear cascade-evaporation model. Cross section measurements for (π/sup +-/, πN) and other more complex pion-induced spallation reactions were measured for the light target nuclei 14 N, 16 O, and 19 F from 45 to 550 MeV incident pion energy. These measurements indicate a broad peak in the excitation functions for both (π,πN) and (π,X) reactions near 180 MeV incident energy. This corresponds to the large resonances observed in the free-particle π + p and π - p cross sections at the same energy. Striking differences in (π,πN) cross section magnitudes are observed among the light nuclei targets. The experimental cross section ratio sigma(π - ,π - n)/sigma(π + ,πN) at 180 MeV is 1.7 +- 0.2 for all three targets. The experimental results are compared to previous pion and analogous proton-induced reactions, to Monte Carlo intranuclear cascade-evaporation calculations, and to a semi-classical nucleon charge exchange model. (108 references) (auth)

  7. Nuclear reactions

    International Nuclear Information System (INIS)

    Lane, A.M.

    1980-01-01

    In reviewing work at Harwell over the past 25 years on nuclear reactions it is stated that a balance has to be struck in both experiment and theory between work on cross-sections of direct practical relevance to reactors and on those relevant to an overall understanding of reaction processes. The compound nucleus and direct process reactions are described. Having listed the contributions from AERE, Harwell to developments in nuclear reaction research in the period, work on the optical model, neutron capture theory, reactions at doorway states with fine structure, and sum-rules for spectroscopic factors are considered in more detail. (UK)

  8. High energy nuclear collisions

    Indian Academy of Sciences (India)

    We review some basic concepts of relativistic heavy-ion physics and discuss our understanding of some key results from the experimental program at the relativistic heavy-ion collider (RHIC). We focus in particular on the early time dynamics of nuclear collisions, some result from lattice QCD, hard probes and photons.

  9. Nuclear reactions

    International Nuclear Information System (INIS)

    Corner, J.; Richardson, K.; Fenton, N.

    1990-01-01

    Nuclear reactions' marks a new development in the study of television as an agency of public policy debate. During the Eighties, nuclear energy became a major international issue. The disasters at Three-mile Island and Chernobyl created a global anxiety about its risks and a new sensitivity to it among politicians and journalists. This book is a case-study into documentary depictions of nuclear energy in television and video programmes and into the interpretations and responses of viewers drawn from many different occupational groupings. How are the complex and specialist arguments about benefit, risk and proof conveyed through the different conventions of commentary, interview and film sequence? What symbolic associations does the visual language of television bring to portrayals of the issue? And how do viewers make sense of various and conflicting accounts, connecting what they see and hear on the screen with their pre-existing knowledge, experience and 'civic' expectations. The authors examine some of the contrasting forms and themes which have been used by programme makers to explain and persuade, and then give a sustained analysis of the nature and sources of viewers' own accounts. 'Nuclear Reactions' inquires into the public meanings surrounding energy and the environment, spelling out in its conclusion some of the implications for future media treatments of this issue. It is also a key contribution to the international literature on 'television knowledge' and the processes of active viewing. (author)

  10. Deconfinement and nuclear collisions

    International Nuclear Information System (INIS)

    Sarma, Nataraja

    1992-01-01

    Expensive experiments to detect a deconfined parton phase have been done and are being planned. In these experiments it is hoped that nuclear collisions at relativistic energies will exhibit signals of this new phase. So far all the results may be interpreted in terms of independent nucleon-nucleon interactions. These elementary collisions at very high energies are therefore worth examination since each such collision produces a highly excited entity which emits a large number of hadrons. In the hadronic phase this results in the GS multiplicity distribution. In the parton phase, parton branching results in the popular negative binomial distribution. Though neither the GS nor the NB distribution alone agrees with the data beyond 200 GeV, it is fitted exceedingly well by a weighted sum of the two distributions. Since the negative binomial distribution arises from the branching of partons, we interpret the increase with energy of the negative binomial component in the weighted sum as the onset of a deconfined phase. The rising cross section for the negative binomial component parallels very closely the inclusive cross section for hadron jets which is also considered a consequence of partons branching. The consequences of this picture to nuclear collisions is discussed. (author). 8 refs., 9 figs., 3 tabs

  11. Nuclear energy release in hadron-nucleus collisions

    International Nuclear Information System (INIS)

    Strugalski, Z.; Strugalska-Gola, E.

    1998-01-01

    Energy release process in nuclear reactions induced by fast hadrons in hadron-nucleus collisions is discussed. Some portion of the internal nuclear energy is released when the locally damaged in a collision, and instable therefore, residual target nucleus transits itself into light nuclear fragments (nucleons, D, T) and a stable lighter final nucleus or some number of stable lighter nuclei. It is not excluded that in some of the collisions the induced intranuclear nuclear reactions may be energy overcompensating. Corresponding reconnaissance should be made - in analysing the nuclear reactions induced in hadron-nucleus collisions

  12. Transparency in high-energy nuclear collisions

    International Nuclear Information System (INIS)

    Karol, P.J.

    1992-01-01

    Problems associated with transparency schemes based on sharp cutoff models are discussed. The soft spheres model of hadron-nucleus and nucleus-nucleus collisions has been used to explore the influence of the realistic nuclear density geometry on transparency. An average nuclear transparency and an average reaction transparency are defined and their dependence on target and projectile dimensions and on the hadron-nucleon collision cross section are described. The results are expected to be valid for projectile energies above several hundred MeV/nucleon through the ultrarelativistic regime. For uniform (hard sphere) nuclear profiles, methods for obtaining effective total transparencies are suggested

  13. 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.

  14. Nuclear reactions as structure probes

    International Nuclear Information System (INIS)

    Fernandez, Bernard; Cugnon, Joseph; Roussel-Chomaz, Patricia; Sparenberg, Jean-Marc; Oliveira Santos, Francois de; Bauge, Eric; Poves, Alfredo; Keeley, Nicholas; Simenel, Cedric; Avez, Benoit; Lacroix, Denis; Baye, Daniel; Cortina-Gil, Dolores; Pons, Alexandre

    2007-09-01

    This publication gathers courses which aim at giving a view on new experiments which are performed by using radioactive beams, notably low intensity beams, in different accelerators, and allow the structure of very exotic nuclei to be characterized. Experimental as well as theoretical aspects are thus addressed. The contributions propose: a brief history of nuclear reactions and of instruments used to study them from the discovery of nucleus to the DWBA (Distorted Wave Born Approximation); an overview of nuclear reactions; experimental techniques; the theory of collisions at low energy; resonant elastic scattering, inelastic scattering and astrophysical reactions; to probe nuclear structure with nucleons; shell model and spectroscopic factors; analysis of transfer reactions and determination of spectroscopic factors; microscopic approaches of nuclear dynamics; theoretical aspects of dissociation reactions; experimental aspects of knockout reactions; research in oenology with the chemical characterisation of defective ageing of dry white wines

  15. Strangeness in nuclear collisions

    International Nuclear Information System (INIS)

    Gazdzicki, M.; Roehrich, D.

    1996-01-01

    Data on the mean multiplicity of strange hadrons produced in minimum bias proton-proton and central nucleus-nucleus collisions at momenta between 2.8 and 400 GeV/c per nucleon have been compiled. The multiplicities for nucleon-nucleon interactions were constructed. The ratios of strange particle multiplicity to participant nucleon as well as to pion multiplicity are larger for central nucleus-nucleus collisions than for nucleon-nucleon interactions at all studied energies. The data at AGS energies suggest that the latter ratio saturates with increasing masses of the colliding nuclei. The strangeness to pion multiplicity ratio observed in nucleon-nucleon interactions increases with collision energy in the whole energy range studied. A qualitatively different behaviour is observed for central nucleus-nucleus collisions: the ratio rapidly increases when going from Dubna to AGS energies and changes little between AGS and SPS energies. This change in the behaviour can be related to the increase in the entropy production observed in central nucleus-nucleus collisions at the same energy range. The results are interpreted within a statistical approach. They are consistent with the hypothesis that the quark gluon plasma is created at SPS energies, the critical collision energy being between AGS and SPS energies. (orig.)

  16. Theoretical studies in nuclear reactions and nuclear structure

    International Nuclear Information System (INIS)

    Wallace, S.J.

    1991-05-01

    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

  17. A method of simulating and visualizing nuclear reactions

    International Nuclear Information System (INIS)

    Atwood, C.H.; Paul, K.M.

    1994-01-01

    Teaching nuclear reactions to students is difficult because the mechanisms are complex and directly visualizing them is impossible. As a teaching tool, the authors have developed a method of simulating nuclear reactions using colliding water droplets. Videotaping of the collisions, taken with a high shutter speed camera and run frame-by-frame, shows details of the collisions that are analogous to nuclear reactions. The method for colliding the water drops and videotaping the collisions are shown

  18. Comparison of models of high energy nuclear collisions

    International Nuclear Information System (INIS)

    Gyulassy, M.

    1978-01-01

    The treatment of high energy nuclear reaction models covers goals of such collisions, the choice of theoretical framework, the zoo of models (p inclusive), light composites, models versus experiment, conclusions drawn, needed experiments, and pion production. 30 diagrams

  19. Nuclear Reaction Data Centers

    International Nuclear Information System (INIS)

    McLane, V.; Nordborg, C.; Lemmel, H.D.; Manokhin, V.N.

    1988-01-01

    The cooperating Nuclear Reaction Data Centers are involved in the compilation and exchange of nuclear reaction data for incident neutrons, charged particles and photons. Individual centers may also have services in other areas, e.g., evaluated data, nuclear structure and decay data, reactor physics, nuclear safety; some of this information may also be exchanged between interested centers. 20 refs., 1 tab

  20. The unified theory of nuclear reactions

    International Nuclear Information System (INIS)

    Tobocman, W.

    A unified nuclear reaction theory is a formalism for the scattering reactions of many-body nuclear systems which is capable of describing both direct interaction and compound nucleus formation processes. The Feshbach projection operator formalism is the original unified nuclear reaction theory. An alternative unified nuclear reaction theory called the X-matrix formalism is described. The X-matrix formalism is a generalization of the Brown-de Dominicis formalism. It does not require projection operators and is readly applied to rearrangement collisions

  1. Reaction mechanism in high energy heavy-ion collisions

    International Nuclear Information System (INIS)

    Tanihata, Isao.

    1982-04-01

    The reaction mechanism in high energy heavy-ion collision is discussed. The discussion is mainly based on the experimental data. Empirical equations have been given for the total cross-sections of nucleus-nucleus reactions and the reaction cross-sections. These cross-sections are well described by the geometrical size of the colliding nuclei. The cross-sections are also understood by microscopic calculation. The charged particle multiplicity gives additional information about the geometrical aspect of heavy ion collision. The data suggested that the total energy, independent of projectile size, is most important for determining the multiplicity. The inclusive proton spectrum in a heavy ion collision showed two distinct regions. The one is the fragment region, and the other the participant region. The spectral shapes of inclusive pion spectra are reasonably well explained by the Coulomb interaction of pions with nuclear fragments. The high energy heavy ion reaction occurs in the overlap region of the projectile and target. This has been tested by measuring the number of participants for various reactions. The space and the time structure of the collision are also discussed in this paper as well as the dynamical aspects of the collision. (Kato, T.)

  2. Fragmentation processes in nuclear reactions

    International Nuclear Information System (INIS)

    Legrain, R.

    1984-08-01

    Projectile and nuclear fragmentation are defined and processes referred to are recalled. The two different aspects of fragmentation are considered but the emphasis is also put on heavy ion induced reactions. The preliminary results of an experiment performed at GANIL to study peripheral heavy ions induced reactions at intermediate energy are presented. The results of this experiment will illustrate the characteristics of projectile fragmentation and this will also give the opportunity to study projectile fragmentation in the transition region. Then nuclear fragmentation is considered which is associated with more central collisions in the case of heavy ion induced reactions. This aspect of fragmentation is also ilustrated with two heavy ion experiments in which fragments emitted at large angle have been observed

  3. Interferometry of high energy nuclear collisions

    International Nuclear Information System (INIS)

    Padula, S.S.

    1990-01-01

    The interferometry is used for determining large space time dimensions of the Quark Gluon Plasma formed in high energy nuclear collisions or in high multiplicity fluctuations in p-barp collisions. (M.C.K.)

  4. Inner shell ionization accompanying nuclear collisions

    International Nuclear Information System (INIS)

    Sujkowski, Z.

    1987-01-01

    Selected phenomena leading to inner shell ionization and being of relevance for nuclear physics are discussed. The selection emphasizes the K-shell ionization induced in head-on collisions by fast light and medium-heavy ions. Cross-sections are reviewed. Effects of multiple inner shell ionization on the K X-ray spectra are illustrated with recent results. Implications for nuclear experiments are noted. Use of atomic observables as clocks for proton induced nuclear reactions is reviewed. Prospects for H.I. reactions are discussed. Preliminary experimental results on the direct K-shell ionization accompanying H.I. fusion reactions are presented. The post-collisional K-shell ionization due to internal conversion of γ-rays is discussed as the dominating contribution to the ionization for residues of dissipative nuclear reactions with Z > 40. Systematics of the corresponding K X-ray multiplicities are presented for rotational nuclei. These multiplicity values can be used for determining cross-sections for e.g. incomplete fusion reactions. Examples of such applications are given. Also discussed is the use of target K X-rays for normalization purposes and of the post-collisional, residue K X-rays in the studies of high spin phenomena. 96 references, 35 figures, 3 tables

  5. Central collisions in intermediate energy heavy-ion reactions

    International Nuclear Information System (INIS)

    Wong, C.Y.

    1979-01-01

    The critical collisions in intermediate energy heavy-ion reactions are examined from both a microscopic and macroscopic viewpoint. In the microscopic description the proper tool is the extended TDHF approximation involving both the mean field and the particle collisions. To understand the underlying physics, the effect of the mean field and the effect of particle collisions are studied separately. It is found that th sudden increase in the density of the overlapping region can cause the volcano effect, leading to the complete disintegration of one of the nuclei. The self-consistent mean field also gives rise to the bunching instability when the two Fermi spheres of the colliding nucleons separate. The collision between nucleons, on the other hand, leads to irreversible dissipation, thermalization, and the possibility of a hydrodynamical description of the dynamics. Next is studied the dynamics of central collisions using the hydrodynamical description for many combinations of targets and projectiles at different energies. The formation of shock waves, sidesplash, and the complete disintegration of the whole nucleus are examined. Nuclear viscosity is found to affect the angular distribution of the reaction products and also the maximum compression ratio achieved during the collision. 28 references

  6. Fragmentation processes in nuclear reactions

    International Nuclear Information System (INIS)

    Baur, G.; Roesel, F.; Trautmann, D.; Shyam, R.

    1983-10-01

    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.)

  7. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2002-01-01

    Full text: Department of Nuclear Reactions has had a very productive year. We have carried out our work in close collaborations with physicists from many laboratories, home and foreign. The following reports cover three major domains of our activities: nuclear, material and atomic physics. * Nuclear physics: In collaboration with scientists from Ukraine experimental studies of nuclear reaction induced by heavy ions from the Warsaw Cyclotron have been performed. The aim of the experiments is to study nuclear reactions leading to the exotic light nuclei in exit channels and energy dependence of the nucleus - nucleus interactions. Proton induced charge-exchange reactions were investigated theoretically by means of multistep-direct model. Good agreement with the experimental data was achieved. A novel approach to the problem of the nuclear liquid → gas phase transition was proposed, based on synergetics - a domain of science dealing with self-organization in macroscopic systems. Decay properties of the Roper resonance were studied. Final analysis of the analysing powers for the polarized deuterons scattered on protons was accomplished. Experimental programme of the near-threshold meson production in proton - proton scattering has been started in collaboration with Forschungszentrum. Juelich. * Atomic physics: Spectra of the X-rays emitted by energetic sulphur ions scattered off carbon atoms were analysed in order to study the role of the multiple charge states of the inner shells in the dynamics of the collision process. Ionization probabilities in collision of oxygen ions with gold atoms were measured. The observed disagreement of the experimental data with the theoretical predictions suggest a strong effect generated by the sub-shell couplings. * Materials research: Ion channelling method was applied to investigate transformation of the defects in Al x Ga 1-x As crystalline layers. Activities of our colleagues in didactics have grown considerably. Lectures

  8. Statistical nuclear reactions

    International Nuclear Information System (INIS)

    Hilaire, S.

    2001-01-01

    A review of the statistical model of nuclear reactions is presented. The main relations are described, together with the ingredients necessary to perform practical calculations. In addition, a substantial overview of the width fluctuation correction factor is given. (author)

  9. Theoretical interpretation of data from high-energy nuclear collisions

    International Nuclear Information System (INIS)

    Fai, G.

    1988-09-01

    Nuclear collision data at energies ranging from medium to relativistic are interpreted theoretically. The major objective is a better understanding of high-energy heavy-ion collisions, with particular emphasis on the properties of excited nuclear matter. Further progress towards a satisfactory description of excited subsaturation nuclear matter is achieved. The mean free path of a nucleon in nuclear matter, which is a critical parameter in assessing the applicability of certain nuclear collision models, is investigated. Experimental information is used together with theoretical concepts in collaborations with experimentalists in order to learn about the reaction mechanism and about excited nuclear matter properties. In the framework of a more strictly theoretical program development, subnuclear degrees of freedom and nonlinear phenomena in model field theories are studied

  10. Introduction to nuclear reactions

    International Nuclear Information System (INIS)

    Satchler, G.R.

    1980-01-01

    This introduction to nuclear reaction phenomena is aimed primarily but not exclusively at readers at the undergraduate student level. An overview of the subject is presented in the first two chapters entitled - Some background information and Introduction to nuclear reactions. The third chapter reviews scattering theory with emphasis on the underlying physical ideas and also provides schematic entrees to the more advanced topics. The physical models which have been developed to account for the various aspects of nuclear phenomena are described in more detail in chapter 4. References and exercises are appended to each chapter. (U.K.)

  11. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2003-01-01

    Full text: In 2002, the Department has been involved in two new experimental programmes. Our colleagues led by Prof. Pawel Zupranski joined a large international collaboration HERMES and took part in experiments at DESY devoted to the study of the spin structure of the nucleon. Another group directed by Associate Prof. Bogdan Zwieglinski has worked on a conceptual design of a new generation detector PANDA (Proton-Antiproton Detection) which will be used in future experiments at GSI. Moreover, the experimental programmes covering three major domains of our scientific activities: nuclear physics, materials research and atomic physics were continued. - Nuclear physics: Experimental studies of nuclear reactions induced by heavy ions provided by the Warsaw U-200P Cyclotron were performed in collaboration with scientists from the Institute for Nuclear Studies in Kiev, Ukraine. The aim of the experiments was to investigate isotopic effects in the scattering of 11 B from carbon nuclides. Also, excited states of 6 Li predicted theoretically but never seen in experiments were investigated by means of one-neutron transfer reactions. Proton induced reactions were investigated theoretically by means of the multistep-direct model. Good agreement with the experimental data was achieved. The mechanism of fragments production in collisions of 197 Au with a gold target in the wide range of energies was studied by ALADIN and INDRA Collaborations. The production of η mesons from proton - proton collisions was investigated experimentally at the Juelich Cooler Synchrotron COSY. - Atomic physics: The ionisation of Au, Bi, Th and U atoms by Si ions was investigated in collaboration with the Swietokrzyska Academy, Kielce, and the University of Erlangen-Nuernberg. - Materials research: The sensitivity of the Solid State Nuclear Track PM-355 detectors was tested against intensive gamma and electron radiation. Moreover, using a monoenergetic sulphur ion beam from the Warsaw Cyclotron, the

  12. Studies of Fluctuation Processes in Nuclear Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Ayik, Sakir [Tennessee Technological Univ., Cookeville, TN (United States). Dept. of Physics

    2016-04-14

    The standard one-body transport approaches have been extensively applied to investigate heavy-ion collision dynamics at low and intermediate energies. At low energies the approach is the mean-field description of the time-dependent Hartree-Fock (TDHF) theory. At intermediate energies the approach is extended by including a collision term, and its application has been carried out mostly in the semi-classical framework of the Boltzmann-Uhling-Uhlenbeck (BUU) model. The standard transport models provide a good understanding of the average properties of the collision dynamics in terms of the effective interactions in both low and intermediate energies. However, the standard models are inadequate for describing the fluctuation dynamics of collective motion at low energies and disassembling of the nuclear system into fragments at intermediate energies resulting from the growth of density fluctuations in the spinodal region. Our tasks have been to improve the standard transport approaches by incorporating fluctuation mechanisms into the description. There are mainly two different mechanisms for fluctuations: (i) Collisional fluctuations generated by binary nucleon collisions, which provide the dominant mechanism at intermediate energies, and (ii) One-body mechanism or mean-field fluctuations, which is the dominant mechanism at low energies. In the first part of our project, the PI extended the standard transport model at intermediate energies by incorporating collisional mechanism according to the “Generalized Langevin Description” of Mori formalism. The PI and his collaborators carried out a number of applications for describing dynamical mechanism of nuclear multi fragmentations, and nuclear collective response in the semi-classical framework of the approach, which is known as the Boltzmann-Langevin model. In the second part of the project, we considered dynamical description at low energies. Because of the effective Pauli blocking, the collisional dissipation and

  13. Perspectives in high energy nuclear collisions

    International Nuclear Information System (INIS)

    Rafelski, J.

    1983-08-01

    This report gives an overview of some aspects of hadronic physics relevant for the conception of a research facility devoted to the study of high energy nuclear collisions. Several concepts to be studied in nuclear collisions are selected, with emphasis placed on the properties and nature of the quark-gluon plasma, the formation of the plasma state in the central region and its anticipated lifetime, and the observability, through strangeness content of this new form of nuclear matter. (orig.)

  14. Nuclear reactions. An introduction

    Energy Technology Data Exchange (ETDEWEB)

    Paetz gen. Schieck, Hans [Koeln Univ. (Germany). Inst. fuer Kernphysik

    2014-03-01

    Modern, self-contained introduction to the subject matter. Emphasizes the interplay between theory and experiment. Course-tested tutorial style, contains many derivations. 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 end in sight for either theoretical or experimental developments as shown e.g. by the recent need to introduce more sophisticated three-body interactions to account for an improved picture of nuclear structure and reactions. Yet, it turns out that the internal structure of the nucleons has comparatively little influence on the behavior of the nucleons in nuclei, and nuclear physics - especially nuclear structure and reactions - is thus a field of science in its own right, without much recourse to subnuclear degrees of freedom. This book collects essential material that was presented in the form of lectures notes in nuclear physics courses for graduate students at the University of Cologne. It follows the course's approach, conveying the subject matter by combining experimental facts and

  15. Nuclear reactions. An introduction

    International Nuclear Information System (INIS)

    Paetz gen. Schieck, Hans

    2014-01-01

    Modern, self-contained introduction to the subject matter. Emphasizes the interplay between theory and experiment. Course-tested tutorial style, contains many derivations. 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 end in sight for either theoretical or experimental developments as shown e.g. by the recent need to introduce more sophisticated three-body interactions to account for an improved picture of nuclear structure and reactions. Yet, it turns out that the internal structure of the nucleons has comparatively little influence on the behavior of the nucleons in nuclei, and nuclear physics - especially nuclear structure and reactions - is thus a field of science in its own right, without much recourse to subnuclear degrees of freedom. This book collects essential material that was presented in the form of lectures notes in nuclear physics courses for graduate students at the University of Cologne. It follows the course's approach, conveying the subject matter by combining experimental facts and experimental

  16. Contribution to very inelastic collisions. Emission mechanism of light charged particles and angular momentum transfer in 40Ar (280 MeV) + 58Ni nuclear reactions

    International Nuclear Information System (INIS)

    Babinet, R.

    1981-07-01

    This work ends a particularly detailed study on very inelastic collisions in 40 A (280 MeV) + 58 Ni reaction. The two experiments in coincidence (fragment-fragment and particle-fragment) which are this work basis, essentially experimental, are the following of the very precise inclusive measurements already done on this system. They allowed to precise many important aspects of the reaction mechanism. Conclusions from a precise analysis of the fragment kinematics near the mass symmetry is the new aspect of this study. Information implicitely contained in the two complementary fragment angular correlation width are particularly detailed. Concerning the particle-fragment coincidence experiment, a quantitative analysis method of the invariant cross sections (in the reaction plane) has been developed; it shows clearly what is the origin of the emitted particles. The result of a two-stage mechanism allows to interpret simply the anisotropy out-of-plane of the alpha particle emission. The individual spin has been obtained for the first time for each of the two fragments of very inelastic collisions in nearly all the mass asymmetry domain [fr

  17. Investigations of nuclear structure and nuclear reactions induced by complex projectiles. Technical progress report, November 1, 1978-October 31, 1979

    International Nuclear Information System (INIS)

    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

  18. Inelastic collisions of heavy ions and their reaction mechanisms; Collisions inelastiques d'ions lourds et mecanismes de reaction

    Energy Technology Data Exchange (ETDEWEB)

    Scarpaci, J.A

    2004-06-01

    This work is dedicated to the study of inelastic collisions of heavy ions. Most experiments took place in Ganil facility. The 2 first chapters introduce the notion of inelastic scattering of heavy ions. The third chapter deals with target excitation, giant monopolar or dipolar or quadrupolar resonances ant the multi-phonon concept and presents relevant experimental results from the Ca{sup 40} + Ca{sup 40} nuclear reaction at 50 MeV/A. The fourth chapter is dedicated to nuclear processes involved in inelastic collisions: pick-up break-up mechanisms, the angular distribution of emitted protons and the towing mode. These notions are applied to the reaction Zr{sup 90}(Ar{sup 40}, Ar{sup 40}'). The fifth chapter presents the solving of the time dependent Schroedinger equation (TDSE) applied to the wave function of a particle plunged in a variable potential. TDSE solving is applied to the break-up of Be{sup 11}. These calculations have been validated by comparing them with experimental results from the nuclear reaction Ti{sup 48}(Be{sup 11}, Be{sup 10} + n + {gamma}) that is described in the chapter 6. The last chapter presents the advantages of inelastic scattering considered as a tool to study exotic nuclei.

  19. Nuclear fission and reactions

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The nuclear fission research programs are designed to elucidate basic features of the fission process. Specifically, (1) factors determining how nucleons of a fissioning nucleus are distributed between two fission fragments, (2) factors determining kinetic energy and excitation energies of fragments, and (3) factors controlling fission lifetimes. To these ends, fission studies are reported for several heavy elements and include investigations of spontaneous and neutron-induced fission, heavy ion reactions, and high energy proton reactions. The status of theoretical research is also discussed. (U.S.)

  20. Solar nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Kocharov, G

    1978-04-01

    The current state of neutrino solar astrophysics is outlined, showing the contradictions between the experimental results of solar neutrino detection and the standard solar models constructed on the basis of the star structure and development theory, which give values for high-energy neutrino fluxes considerably exceeding the upper experimental limit. A number of hypotheses interpreting the experimental results are summarized. The hypotheses are critically assessed and experiments are recommended for refining or verifying experimental data. Also dealt with are nuclear reactions in the Sun, as is the attempt to interpret the anomalous by high /sup 3/He fluxes from the Sun and the relatively small amounts of solar neutrinos and gamma quanta. The importance is emphasized of the simultaneous and complex measurement of the fluxes of neutrons, gamma radiation, and isotopes of hydrogen, helium, and boron from the Sun as indicators of nuclear reactions in the Sun.

  1. Nuclear reactions in astrophysics

    International Nuclear Information System (INIS)

    Cardenas, M.

    1976-01-01

    It is revised the nuclear reactions which present an interest in astrophysics regarding the explanation of some problems such as the relative quantity of the elements, the structure and evolution of the stars. The principal object of the study is the determination of the experimental possibilities in the field of astrophysics, of an accelerator Van de Graaff's 700 KeV type. Two hundred nuclear reactions approximately, were found, and nothing or very little has been done in the intervals of energy which are of interest. Since the bombardment energies and the involved sections are low in some cases, there are real possibilities, for the largest number of stars to obtain important statistical data with the above mentioned accelerator, taking some necessary precautions. (author)

  2. 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 ...

  3. Nuclear reactions in astrophysics

    International Nuclear Information System (INIS)

    Arnould, M.; Rayet, M.

    1990-01-01

    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

  4. Low Energy Nuclear Reactions?

    CERN Multimedia

    CERN. Geneva; Faccini, R.

    2014-01-01

    After an introduction to the controversial problem of Low Energy Nuclear Reactions (LENR) catalyzed by neutrons on metallic hydride surfaces we present the results of an experiment, made in collaboration with ENEA Labs in Frascati, to search neutrons from plasma discharges in electrolytic cells. The negative outcome of our experiment goes in the direction of ruling out those theoretical models expecting LENR to occur in condensed matter systems under specific conditions. Our criticism on the theoretical foundations of such models will also be presented.

  5. Reaction Dynamics and Nuclear Structure Studies of n-Rich Nuclei Around 48Ca via Deep Inelastic Collisions with Heavy-Ions

    International Nuclear Information System (INIS)

    Leoni, S.

    2011-01-01

    The population and γ decay of neutron rich nuclei around 48 Ca has been measured at Legnaro National Laboratory with the PRISMA-CLARA setup, using deep-inelastic collisions on 64 Ni, at 5.9 MeV/A. The reaction properties of the main products are investigated, focusing on total cross-sections and energy integrated angular distributions. Gamma spectroscopy studies are also performed for the most intense transfer channels, making use of angular distributions and polarization measurements to firmly establish spin and parity of the excited states. In the case of 49 Ca candidates for particle-core couplings are investigated and interpreted on basis of lifetime measurements and comparison with model predictions. (author)

  6. On transient effects in violent nuclear collisions

    International Nuclear Information System (INIS)

    Suraud, E.; Belkacem, M.; Feng-Shou Zhang; Academia Sinica, Lanzhou, GS

    1993-01-01

    It is shown that the numerical simulations of the recently developed Boltzmann-Langevin model exhibit large dynamical fluctuations in momentum space during the early stages of heavy-ion collisions, which arise from an interplay between the nuclear meanfield and binary collisions. It is pointed out that this transient behaviour provides an initial seed for the development of density fluctuations, and could strongly influence the particle production cross-sections at subthreshold energies. (author) 13 refs.; 3 figs

  7. Models of high energy nuclear collisions

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1978-06-01

    The discussion covers nuclear collisions at relativistic energies including classes of high energy nucleus--nucleus collisions, and the kinetics of a central collision; and the asymptotic hadron spectrum including known and unknown hadrons, the relevance of the spectrum and the means of its study, thermodynamics of hadronic matter, examples of hadronic spectra, the temperature, composition of the initial fireball and its expansion, isoergic expansion with no pre-freezeout radiation, isentropic expansion of the fireball, the quasi-dynamical expansion, and finally antinuclei, hypernuclei, and the quark phase. 28 references

  8. The nuclear reaction matrix

    International Nuclear Information System (INIS)

    Krenciglowa, E.M.; Kung, C.L.; Kuo, T.T.S.; Osnes, E.; and Department of Physics, State University of New York at Stony Brook, Stony Brook, New York 11794)

    1976-01-01

    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 2 /sub p/ by the method of Tsai and Kuo. The treatment of Q 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

  9. On Markov processes in the hadron-nuclear and nuclear-nuclear collisions at superhigh energies

    International Nuclear Information System (INIS)

    Lebedeva, A.A.; Rus'kin, V.I.

    2001-01-01

    In the article the possibility of the Markov processes use as simulation method for mean characteristics of hadron-nuclear and nucleus-nuclear collisions at superhigh energies is discussed. The simple (hadron-nuclear collisions) and non-simple (nucleus-nuclear collisions) non-uniform Markov process of output constant spectrum and absorption in a nucleon's nucleus-target with rapidity y are considered. The expression allowing to simulate the different collision modes were obtained

  10. Department of Nuclear Reaction - Overview

    International Nuclear Information System (INIS)

    Budzanowski, A.

    2002-01-01

    Full text: Our research in 2001 can be characterized by a wide range of various subjects e.g. search for new physics in Au + Au collisions at the energy in the centre of mass per nucleon pair √ s NN = 200 GeV through hunting dibaryon formation in p + p → K + + D (dibaryon) reaction to the application of the random matrix theory taken from nuclear reaction studies in the analysis of fluctuations of the stock exchange time and space correlations. Heavy ion reactions have been studied in a broad range of energies. At low energy of the 12 C ions (E CM = 25.57 MeV), delivered by the Warsaw U200P cyclotron, the reactions induced on 11 B target were studied. Coupling effects between various reaction channels were found. At the energies corresponding to the liquid-to-gas phase transition, the onset of the flow phenomena was found in the multifragmentation of the 197 Au nuclei induced by a sequence of projectiles p, 4 He, 12 C of the energies from 1-3 GeV per nucleon. Finally, evidence of the melting of the baryonic structure of the colliding nuclei was found at the highest available energies of 200 GeV per nucleon pair, in the collision of gold nuclei studied at the Relativistic Heavy Ion Collider within the BRAHMS and PHOBOS collaboration. We entered a new collaboration HIRES with the aim to discover S = -1 dibaryonic state by studying the reaction p+p → K + +D. So far many attempts to prove experimentally the existence of a dibaryonic state failed. We hope to use the unique properties of the Big Karl spectrometer to prove the existence of a sharp peak in the energy spectra of kaons. To do so, we have to reduce strongly the background of pions. A diffusely reflective threshold Cherenkov detector made from silica aerogel was designed. Preliminary tests indicate that pionic signals can be reduced by a factor of 58. Extensive studies of the mechanism of generating collective levels and the energy gap by means of diagonalizing matrices with random elements ended up with

  11. Laser induced nuclear reactions

    International Nuclear Information System (INIS)

    Ledingham, Ken; McCanny, Tom; Graham, Paul; Fang Xiao; Singhal, Ravi; Magill, Joe; Creswell, Alan; Sanderson, David; Allott, Ric; Neely, David; Norreys, Peter; Santala, Marko; Zepf, Matthew; Watts, Ian; Clark, Eugene; Krushelnick, Karl; Tatarakis, Michael; Dangor, Bucker; Machecek, Antonin; Wark, Justin

    1998-01-01

    Dramatic improvements in laser technology since 1984 have revolutionised high power laser technology. Application of chirped-pulse amplification techniques has resulted in laser intensities in excess of 10 19 W/cm 2 . In the mid to late eighties, C. K. Rhodes and K. Boyer discussed the possibility of shining laser light of this intensity onto solid surfaces and to cause nuclear transitions. In particular, irradiation of a uranium target could induce electro- and photofission in the focal region of the laser. In this paper it is shown that μCi of 62 Cu can be generated via the (γ,n) reaction by a laser with an intensity of about 10 19 Wcm -2

  12. Department of Nuclear Reactions - Overview

    International Nuclear Information System (INIS)

    Budzanowski, A.

    1999-01-01

    Full text: The year 1998 can be considered as very successful both in harvesting important results from the existing collaborations as well as establishing new ones. In the frame of the COSY-11 collaboration cross section for η' production in p-p collision close to the threshold has been measured. In the region of excess energy between 1.5 and 4.1 MeV the η' cross sections are much lower than those of the π 0 and η production. There seems to be no indication that N * resonance doorway-like state governs the reaction mechanisms. The determined coupling constant g η'pp appears to be consistent with the prediction of the simple quark model. Results were published in Phys. Rev. Letters. Using the GEM detector, investigations of the isospin symmetry breaking were performed. Two reactions channels 3 Heπ 0 and 3 Hπ + from the reaction at proton momenta 700, 767, and 825 MeV/c were measured. Data analysis is in progress. The model of the meson cloud in the nucleon which is a speciality of our department has been successfully applied to explain the leading proton and neutron cross sections from the e + or e - proton collisions at the HERA ring. General formulas to calculate polarization of the particles with spin transmitted through the barrier in the presence of strong magnetic fields were obtained. New collaboration between our laboratory and the Institute for Nuclear Research in Kiev has been established. One PhD thesis was completed in the frame of this collaboration. We joined the new collaboration with Lund University concerning studies of hot nuclear matter properties using heavy ions from CELSIUS ring. First test of the phoswich detector for the forward wall was performed in Uppsala. Isoscalar giant dipole resonance strength distribution 3 ℎω has been evaluated in 208 Pb in the space of 1p1h and 2p2h excitation. The centroid energy of this state can directly be related to the nuclear incompressibility module. Our result indicates rather large values of

  13. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2001-01-01

    Full text: The last year of the twentieth-century was productive for our Department. Although the name of the Department suggests that we are all involved in investigations of nuclear reactions, in fact our activities are spread over three major domains: nuclear, atomic and material physics. Some of the projects we were involved in the last year have been realized using national facilities and accelerators, like the Van de Graaff accelerator of our Department at 69 Hoza Street, Warsaw Cyclotron U-200P of Warsaw University, and compact C30 cyclotron of our Institute at Swierk. Other projects were done abroad, using facilities of the Gesellschaft fuer Schwerionenforschung in Darmstadt, Institute de Physique Nucleaire at Orsay, and Universitaet Erlangen-Nuernberg in Erlangen. We carried out our work in close collaborations with physicists from many laboratories, Polish and foreign. - Low energy nuclear reactions. In collaboration with scientists from Ukraine experiments, using heavy ion beam provided by the Warsaw Cyclotron, were started. The aim of the experiments is to study nuclear reactions leading to the exotic light nuclei in exit channels and energy dependence of the nucleus - nucleus interaction. Efforts were made to develop a multistep direct model of nuclear reactions. In the model contributions due to the low energy collective excitations were taken into account. Good agreement with the experimental data was achieved. - Multifragmentation of relativistic heavy ions. ALADIN Collaboration studied multifragmentation reactions induced by relativistic heavy ions. The main activities of our scientists concentrated on an upgrade of the detecting system in order to replace photo multipliers with large area avalanche photodiodes in the central section of the TOF-wall. Some tests of the photodiodes manufactured by Advanced Photonix Inc. were performed using standard β - and γ-sources. - Structure of a nucleon. Decay properties of the Roper resonance were studied. A

  14. Global Lambda hyperon polarization in nuclear collisions

    Czech Academy of Sciences Publication Activity Database

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Bielčík, J.; Bielčíková, Jana; Chaloupka, P.; Federič, Pavol; Federičová, P.; Harlenderová, A.; Kocmánek, Martin; Kvapil, J.; Lidrych, J.; Rusňák, Jan; Rusňáková, O.; Šaur, Miroslav; Šimko, Miroslav; Šumbera, Michal; Trzeciak, B. A.

    2017-01-01

    Roč. 548, č. 7665 (2017), č. článku 23004. ISSN 0028-0836 R&D Projects: GA MŠk LG15001; GA MŠk LM2015054 Institutional support: RVO:61389005 Keywords : STAR collaboration * heavy ion collisions * vorticity Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nuclear physics Impact factor: 40.137, year: 2016

  15. High energy nuclear collisions: Theory overview

    Energy Technology Data Exchange (ETDEWEB)

    Fries, R.J.

    2010-08-01

    We review some basic concepts of relativistic heavy-ion physics and discuss our understanding of some key results from the experimental program at the relativistic heavy-ion collider (RHIC). We focus in particular on the early time dynamics of nuclear collisions, some result from lattice QCD, hard probes and photons.

  16. Nuclear reaction data and nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Paver, N [University of Trieste (Italy); Herman, M [International Atomic Energy Agency, Vienna (Austria); Gandini, A [ENEA, Rome (Italy)

    2001-12-15

    These two volumes contain the lecture notes of the workshop 'Nuclear Reaction Data and Nuclear Reactors: Physics, Design and Safety', which was held at the Abdus Salam ICTP in the Spring of 2000. The workshop consisted of five weeks of lecture courses followed by practical computer exercises on nuclear data treatment and design of nuclear power systems. The spectrum of topics is wide enough to timely cover the state-of-the-art and the perspectives of this broad field. The first two weeks were devoted to nuclear reaction models and nuclear data evaluation. Nuclear data processing for applications to reactor calculations was the subject of the third week. On the last two weeks reactor physics and on-going projects in nuclear power generation, waste disposal and safety were presented.

  17. Reaction mechanisms and staggering in S+Ni collisions

    International Nuclear Information System (INIS)

    D'Agostino, M.; Bruno, M.; Gulminelli, F.; Morelli, L.; Baiocco, G.; Bardelli, L.; Barlini, S.; Cannata, F.; Casini, G.; Geraci, E.; Gramegna, F.; Kravchuk, V.L.; Marchi, T.; Moroni, A.; Ordine, A.; Raduta, Ad.R.

    2011-01-01

    The reactions 32 S+ 58 Ni and 32 S+ 64 Ni are studied at 14.5 A MeV. After a selection of the collision mechanism, we show that important even-odd effects are present in the isotopic fragment distributions when the excitation energy is small. Close to the multifragmentation threshold this staggering appears hidden by the rapid variation of the production yields with the fragment size. Once this effect is accounted for, the staggering appears to be a universal feature of fragment production, slightly enhanced when the emission source is neutron poor. A closer look at the behavior of the production yields as a function of the neutron excess N-Z, reveals that odd-even effects cannot be explained by pairing effects in the nuclear masses alone, but depend in a more complex way on the de-excitation chain.

  18. Nuclear compression effects on pion production in nuclear collisions

    International Nuclear Information System (INIS)

    Sano, M.; Gyulassy, M.; Wakai, M.; Kitazoe, Y.

    1984-11-01

    The pion multiplicity produced in nuclear collisions between 0.2 and 2 AGeV is calculated assuming shock formation. We also correct the procedure of extracting the nuclear equation of state as proposed by Stock et al. The nuclear equation of state would have to be extremely stiff for this model to reproduce the observed multiplicities. The assumptions of this model are critically analyzed. (author)

  19. Preequilibrium Nuclear Reactions

    International Nuclear Information System (INIS)

    Strohmaier, B.

    1988-01-01

    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

  20. On nuclear reaction duration at the range of overlapping resonances

    International Nuclear Information System (INIS)

    Olkhovsky, V.S.

    1981-01-01

    Nuclear reaction duration above the threshold of overlapping resonances is investigated and its importance to obtain a new information on a collision mechanism is evidenced. It is shown also that the duration of resonant nuclear reactions is asymptotically decreasing according to the law[E 2 n(E)] -1 when the energy E and the number of open channels n(E) are increasing [ru

  1. Using MUSIC to study relativistic nuclear collisions

    International Nuclear Information System (INIS)

    1983-01-01

    A large Multiple Sampling Ionization Chamber (MUSIC) has been developed as a part of the Heavy Ion Spectrometer System (HISS). This facility is being used for the study of relativistic nuclear collisions at the Bevalac of Lawrence Berkeley Laboratory. Preliminary data from MUSIC indicate that a charge resolution of one unit should be achieved from Z approximately equal to 7 to Z approximately equal to 100. (author)

  2. Nuclear reaction studies

    International Nuclear Information System (INIS)

    Alexander, J.M.; Lacey, R.A.

    1994-01-01

    Research focused on the statistical and dynamical properties of ''hot'' nuclei formed in symmetric heavy-ion reactions. Theses included ''flow'' measurements and the mechanism for multifragment disassembly. Model calculations are being performed for the reactions C+C, Ne+Al, Ar+Sc, Kr+Nb, and Xe+La. It is planned to study 40 Ar reactions from 27 to 115 MeV/nucleon. 2 figs., 41 refs

  3. Multistep processes in nuclear reactions

    International Nuclear Information System (INIS)

    Hodgson, P.E.

    1988-01-01

    The theories of nuclear reactions are reviewed with particular attention to the recent work on multistep processes. The evidence for compound nucleus and direct interaction reactions is described together with the results of comparisons between theories and experimental data. These theories have now proved inadequate, and there is evidence for multistep processes that take place after the initial direct stage but long before the attainment of the statistical equilibrium characteristic of compound nucleus processes. The theories of these reactions are described and it is shown how they can account for the experimental data and thus give a comprehensive understanding of nuclear reactions. (author)

  4. High energy gamma-ray production in nuclear reactions

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  5. Multiple scattering in the nuclear rearrangement reactions at medium energy

    International Nuclear Information System (INIS)

    Tekou, A.

    1980-09-01

    It is shown that the multiple scattering mechanism is very important in the transfer of the large momenta involved in the nuclear rearrangement reactions at medium energy. In contrast to the usual belief, the reaction cross-section is not very sensitive to the high momenta components of the nuclear wave function. The multiple scattering mechanism is especially important in 4 He(p,d) 3 He reaction around 800 MeV. Here the collisions involving two nucleons of the target nucleus are dominant. The triple collisions contribution is also important. The four collision contribution is negligible in the forward direction and sizeable at large angles. Thus, using the K.M.T. approach in DWBA calculations, the second order term of the optical potential must be included. So, is it not well established that the second term of the K.M.T. optical potential is important for the proton elastic scattering on light nuclei. (author)

  6. High energy nuclear collisions: theory review

    International Nuclear Information System (INIS)

    Fries, Rainer J.

    2009-01-01

    Full text: High Energy Nuclear Collisions are studied at the Relativistic Heavy Ion Collider (RHIC) and, starting next year, also at the Large Hadron Collider (LHC) to study the formation and properties of quark gluon plasma (QGP). This effort is driven by the prediction that above a certain critical temperature quarks and gluons are deconfined. For the past ten years of running RHIC has performed marvelously. Data from RHIC has answered many initial questions, but it has also provided new, more challenging problems to understand the nature of quark gluon plasma and the dynamics of heavy ion collisions. In this talk I review some of the basic concepts of high energy nuclear collisions and quark gluon plasma formation. We also discuss some of the novel and open questions that we are faced with. We discuss recent predictions on properties of hot quantum chromodynamics, emerging signatures for the color glass condensate, the fascinating idea of local P and CP violation in QCD, as well as ongoing research on hard probes and electromagnetic signatures

  7. Influence of the nuclear autocorrelation function on the positron production in heavy-ion collisions

    International Nuclear Information System (INIS)

    Tomoda, T.; Weidenmueller, H.A.

    1983-01-01

    The influence of a nuclear reaction on atomic positron production in heavy-ion collisions is investigated. Using statistical concepts, we describe the nuclear S matrix for a heavy-ion induced reaction as a statistically fluctuating function of energy. The positron production rate is then dependent on the autocorrelation function of this S matrix, and on the ratio of the ''direct'' versus the ''fluctuating'' part of the nuclear cross section. Numerical calculations show that in this way, current experimental results on positron production in heavy-ion collisions can be reproduced in a semiquantitative fashion

  8. Nuclear excitations and reaction mechanisms

    International Nuclear Information System (INIS)

    Fallieros, S.; Levin, F.S.

    1990-01-01

    The main theme of this report is the study and interpretation of the sequence of events that occur during the collisions of nuclear particles. Some of the processes discussed in parts A and B involve short range interactions; others involve interactions of long range. In most of part A one of the particles in the initial or in the final state (or in both) is a photon, which serves as a probe of the second particle, which may be a nucleus, a proton, a pion or any other hadron. The complexity of the processes taking place during the collisions makes it necessary to simplify some aspects of the physical problem. This leads to the introduction of modals which are used to describe a limited number of features in as much detail as possible. The main interest is the understanding of the hadronic excitations which result from the absorption of a photon and the determination of the fundamental structure constants of the target particle. In part B, all the particles are hadrons. The purpose here is to develop and apply optimal quantal methods appropriate for describing the interacting systems. Of particular interest are three-particle collision systems in which the final state consists of three free particles. Part B also considers the process of nuclear fusion as catalyzed by bound muons

  9. Britain's nervous nuclear reaction

    International Nuclear Information System (INIS)

    Foster, G.

    1988-01-01

    The paper concerns the nuclear energy business in the United Kingdom, with emphasis on the management of the industry. A brief history is given of the development of the nuclear power programme and the creation of UKAEA and BNFL. BNFL is responsible for reprocessing at Sellafield, fuel element manufacture at Springfields, fuel reprocessing at Thorp, and uranium enrichment at Caperhurst. The development and management of these projects are discussed with respect to export markets, competition in international markets, commercial skills, and public opinion. (U.K.)

  10. A perspective on relativistic nuclear collisions

    International Nuclear Information System (INIS)

    Glendenning, N.K.; Paris-11 Univ., 91 - Orsay

    1979-01-01

    A quasi-dynamical model for the disassembly of a high energy hadronic fireball has been developed. It is fund that some signals from the early high density stage are expected to survive the expansion stage. Indeed cetain signals, the π /N and K / N ratio at high kinetic energy, are so qualitatively unique in their dependance on target projectile mass, that we believe they will survive a refinement of the collision dynamics. Therefore a determination of the assymptotic form of the hadron spectrum can be made by studying nuclear collisions. The required energies are high (approximately 10 GeV/ nucleon in C.M.), but they are within the reach of present technology

  11. Hipse: an event generator for nuclear collisions at intermediate energies

    International Nuclear Information System (INIS)

    Lacroix, D.; Van Lauwe, A.; Durand, D.

    2003-11-01

    An event generator, HIPSE (Heavy-Ion Phase-Space Exploration), dedicated to the description of nuclear collisions in the intermediate energy range is presented. Based on the sudden approximation and on geometrical hypothesis, it can conveniently simulate heavy-ion interactions at all impact parameters and thus can constitute a valuable tool for the understanding of processes such as neck emission or multifragmentation in peripheral or/and central collisions. After a detailed description of the ingredients of the model, first comparisons with experimental data collected by the INDRA collaboration are shown. Special emphasis is put on the kinematical characteristics of fragments and light particles observed at all impact parameters for Xe+Sn reactions at 25 and 50 MeV/u and Ni + Ni at 82 MeV/u. (authors)

  12. Calculation of Direct photon production in nuclear collisions

    CERN Document Server

    Cepila, J

    2012-01-01

    Prompt photons produced in a hard reaction are not expected to be accompanied by any final state interaction, either energy loss or absorption and one should not expect any nuclear effects at high pT . However, data from the PHENIX experiment indicates large-pT suppression in d+Au and central Au+Au collisions that cannot be accompanied by coherent phenomena. We propose a mechanism based on the energy sharing problem at large pT near the kinematic limit that is induced by multiple initial state interactions and that improves the agreement of calculations with PHENIX data. We calculate inclusive direct photon production cross sections in p+p collisions at RHIC and LHC energies using the color dipole approach without any additional parameter. Our predictions are in good agreement with the available data. Within the same framework, we calculate direct photon production rates in d+A and A+A collisions at RHIC energy. We also provide predictions for the same process in p+A collisions at LHC energy. Since the kinema...

  13. Anisotropy of dilepton emission from nuclear collisions

    International Nuclear Information System (INIS)

    Bratkovskaya, E.L.; Teryaev, O.V.; Toneev, V.D.; Joint Inst. for Nuclear Research, Dubna

    1994-01-01

    Attention is paid to studying the angular characteristics of e + e - pairs created in collisions with nuclear targets at intermediate and relativistic energies. Arising due to general spin and angular momentum constraints, the dilepton anisotropy seems to be quite sensitive to the contribution of different sources and may be used for disentangling these sources (or models) as well as an additional signature of a possible chiral symmetry restoration and phase transition of hadrons into the quark-gluon plasma. An anisotropy estimate for some dilepton sources is given and its relevance to the problems mentioned is discussed

  14. Anisotropy of dilepton emission from nuclear collisions

    Energy Technology Data Exchange (ETDEWEB)

    Bratkovskaya, E.L.; Teryaev, O.V. [Joint Inst. for Nuclear Research, Dubna (Russian Federation). Bogolubov Lab. of Theoretical Physics; Toneev, V.D. [Washington Univ., Seattle, WA (United States). Inst. for Nuclear Theory]|[Joint Inst. for Nuclear Research, Dubna (Russian Federation). Bogolubov Lab. of Theoretical Physics

    1994-11-07

    Attention is paid to studying the angular characteristics of e{sup +}e{sup {minus}} pairs created in collisions with nuclear targets at intermediate and relativistic energies. Arising due to general spin and angular momentum constraints, the dilepton anisotropy seems to be quite sensitive to the contribution of different sources and may be used for disentangling these sources (or models) as well as an additional signature of a possible chiral symmetry restoration and phase transition of hadrons into the quark-gluon plasma. An anisotropy estimate for some dilepton sources is given and its relevance to the problems mentioned is discussed.

  15. Department of Nuclear Reaction - Overview

    International Nuclear Information System (INIS)

    Budzanowski, A.

    2001-01-01

    asymmetry. 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 20 Ne beam at 200 MeV/nucleon on 40 Ar and 14 N 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)

  16. Nuclear excitations and reaction mechanisms

    International Nuclear Information System (INIS)

    Fallieros, S.; Levin, F.S.

    1989-01-01

    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

  17. Studies of fluctuation processes in nuclear collisions

    International Nuclear Information System (INIS)

    Ayik, S.

    1991-02-01

    This report summarizes the progress on grant No. DE-FG05-89ER40530 during the period April 15, 1990 to February 15, 1991. Our studies of heavy-ion collisions in the framework of ''a stochastic one-body transport model'' has progress in several directions. We developed a method for obtaining approximate numerical solutions of the transport-equation in semi-classical limit, i.e., Boltzmann-Langevin equation, and tested the method in realistic cases of heavy-ion collisions at energies below 100 MeV per nucleon. Some results of the numerical simulations for a head-on collision of 12 C + 12 C system is included in this report. Work has also continued on studying the stochastic one-body transport model in a quantal representation, which provides a microscopic basis for a consistent description of dissipation and fluctuation properties of large amplitude collective nuclear motion. The previous derivation of the stochastic one-body transport model was presented within the density matrix formalisam. We generalized this treatment and proposed an alternative derivation of the model by employing the Green's function approach within the real-time path formalism of Keldish. One manuscript has been submitted to Nucl. Phys. A for publication. Two other manuscripts are in preparation for publication. Several seminars and contributed talks were presented at various meeting

  18. Initial angular momentum and flow in high energy nuclear collisions

    Science.gov (United States)

    Fries, Rainer J.; Chen, Guangyao; Somanathan, Sidharth

    2018-03-01

    We study the transfer of angular momentum in high energy nuclear collisions from the colliding nuclei to the region around midrapidity, using the classical approximation of the color glass condensate (CGC) picture. We find that the angular momentum shortly after the collision (up to times ˜1 /Qs , where Qs is the saturation scale) is carried by the "β -type" flow of the initial classical gluon field, introduced by some of us earlier. βi˜μ1∇iμ2-μ2∇iμ1 (i =1 ,2 ) describes the rapidity-odd transverse energy flow and emerges from Gauss's law for gluon fields. Here μ1 and μ2 are the averaged color charge fluctuation densities in the two nuclei, respectively. Interestingly, strong coupling calculations using anti-de Sitter/conformal field theory (AdS/CFT) techniques also find an energy flow term featuring this particular combination of nuclear densities. In classical CGC the order of magnitude of the initial angular momentum per rapidity in the reaction plane, at a time 1 /Qs , is |d L2/d η |≈ RAQs-3ɛ¯0/2 at midrapidity, where RA is the nuclear radius, and ɛ¯0 is the average initial energy density. This result emerges as a cancellation between a vortex of energy flow in the reaction plane aligned with the total angular momentum, and energy shear flow opposed to it. We discuss in detail the process of matching classical Yang-Mills results to fluid dynamics. We will argue that dissipative corrections should not be discarded to ensure that macroscopic conservation laws, e.g., for angular momentum, hold. Viscous fluid dynamics tends to dissipate the shear flow contribution that carries angular momentum in boost-invariant fluid systems. This leads to small residual angular momentum around midrapidity at late times for collisions at high energies.

  19. 1-4 Strangeness Production in Antiproton Induced Nuclear Reactions.

    Institute of Scientific and Technical Information of China (English)

    Feng; Zhaoqing[1

    2014-01-01

    More localized energy deposition is able to be produced in antiproton-nucleus collisions in comparison withheavy-ion collisions due to annihilation reactions. Searching for the cold quark-gluon plasma (QGP) with antiprotonbeamshas been considered as a hot topic both in experiments and in theretical calculations over the past severaldecades. Strangeness production and hypernucleus formation in antiproton-induced nuclear reactions are importancein exploring the hyperon (antihyperon)-nucleon (HN) potential and the antinucleon-nucleon interaction, whichhave been hot topics in the forthcoming experiments at PANDA in Germany.

  20. Rapid nuclear reaction

    International Nuclear Information System (INIS)

    Marcan, P.; Beer, G.

    2008-01-01

    Whereas the completion of blocks 3 and 4 in Mochovce were subject to some discussion, the building of a new unit at Jaslovske Bohunice has remained unnoticed. Not even environmentalists objected. And so far the plans to build a new power plant seem to have been approved without any major discussion about whether Slovakia really needs or does not need a new nuclear power unit. Political statements about a possible future shortage of electricity were enough. The plans of private companies to build their own power plants or the possibility of decreasing the use of energy by savings were disregarded. But a clear answer to the question whether this new power unit will generate electricity for export to other countries has not yet been given. But by the end of this year the government wants to decide whether the new power plant which will cost an estimated 100 billion Slovak crowns (3.3 billions EUR) will be built from public funds in tandem with a private investor or fully financed by private capital. The name of the private investor should become known by the end of this year. (authors)

  1. Microscopic description of nuclear reactions

    International Nuclear Information System (INIS)

    Gorbatov, A.M.

    1992-01-01

    The genealogical series method has been extended to the continuous spectrum of the many-body systems. New nonlinear integral equations have been formulated to perform the microscopical description of the nuclear reactions with arbitrary number of particles. The way to solve them numerically is demonstrated

  2. Kaon production in intermediate-energy nuclear collisions

    International Nuclear Information System (INIS)

    Russkikh, V.N.; Ivanov, Yu.B.

    1992-01-01

    Production of positive kaons in nuclear collisions at intermediate energies (∝ 1-2 GeV/nucleon) is studied within the 3-dimensional fluid dynamics combined with the hadrochemical kinetics for strangeness production. Sensitivity of the kaon probe to a form of the nuclear equation of state is analyzed. The model reproduces total and differential cross sections of Ne+NaF→K + +X and Ne+Pb→K + +X reactions at E lab =2.1 GeV/nucleon, provided a soft equation of state is used. The pion-production data are also well described employing the same equation of state. Predictions are made for the current experiment on kaon production at the SIS accelerator. The obtained results are compared with the predictions of other models. (orig.)

  3. Theoretical interpretation of high-energy nuclear collisions

    International Nuclear Information System (INIS)

    Fai, G.

    1992-06-01

    Nuclear collisions are interpreted theoretically. The nuclear equation of state is studied in a wide energy range. Subnucleonic degrees of freedom are invoked at high energy densities and at short length-scales. Questions of dynamical collision simulations are investigated. Direct support is provided for experiment in the form of collaborative projects. The major objective of this nuclear theory program is a better understanding of the properties of strongly interacting matter on the nuclear energy scale, as manifested in high-energy heavy-ion collisions

  4. Nuclear excitations and reaction mechanisms. Progress report

    International Nuclear Information System (INIS)

    Fallieros, S.; Levin, F.S.

    1986-01-01

    Theoretical research is being conducted on the following topics: photon scattering, gauge invariance and the extension of Siefert's Theorem; retardation effects in photonuclear absorption and the Cabibbo Radicati Sum Rule; isovector transition densities, currents and response functions; the electric polarizability, the magnetic susceptibility and the distribution of oscillator strengths in some elementary systems; relativistic models and processes; properties of skyrmions; multiquark compound bags and the charge form factor of the A = 3 nuclei; nuclear reaction theory; three-particle scattering theory; deuteron-nucleus model calculations; asymptotia in three-particle scattering systems; and time-dependent approach to few-nucleon collisions. Progress in each of these areas is reviewed briefly. A list of invited talks and of publications for the fiscal year 1986 is included. 27 refs

  5. 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.

  6. Atomic nuclei and nuclear reactions. Theory and application

    International Nuclear Information System (INIS)

    Sitenko, A.G.; Tartakovsky, V.K.; Kenjebaev, K.K.; Shunkeyev, K.Sh.; Ismatov, E.I.; Mukhammedov, S.; Comsan, M.N.H.; Djuraev, Sh.Kh.

    2004-01-01

    Full text: The short description of the book preparation by the collective authors from Ukraine, Kazakhstan, Uzbekistan and Egypt is given. The present book is the expanded course of lectures on the theory of nuclei, nuclear reactions and their applications delivered by the authors for a number of years in the Ukrainian National University, Aktubinsk State University of the Kazakhstan Republic, Tashkent National University, Samarkand and Termez State Universities of Uzbekistan Republic, Egyptian National Universities (Al-Az'har, Menoufeya, Suez-Canal and Tanta) and the Institute of Nuclear Physics of the Academy of Sciences of the Republic of Uzbekistan. The lectures present foundations of the modern concepts of the structure of nuclei, on the nature of nuclear processes and nuclear transformations. Main attention in the book was paid to the presentation of the basics and some modern achievements in the field of the theory of nuclei and nuclear reactions. A number of problems was investigated in original works and were not presented in the physics textbooks. The book presents the non-relativistic theory of nuclear reactions, questions of relativistic nuclear physics were not considered here. Non-relativistic theory of nuclear reactions is based on the notions of collision matrix or S-matrix. In absence of consequent microscopic theory, the scattering matrix can be found phenomenological based on definite assumptions on the character of nuclear interactions. Modern applications of nuclear reactions for the development of nuclear methods of analysis are presented. The delayed and nuclear techniques with nuclear reactor, accelerators and radioisotopic sources are considered. The book is designed as a textbook for bachelor and postgraduate students of physical faculties of universities and engineering-physical institutions, lecturers and researchers, working in the field of nuclear physics. The book gives an up-to-date list of references on nuclear reaction theory and

  7. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2004-01-01

    Full text: In spite of reduced personnel the number of papers published and in press exceeded fifty, almost ten more than a year ago. Another good sign is the growing number of PhD students. The following short reports cover the three major domains of our scientific activities: nuclear, material and atomic physics. Nuclear physics: The structure of light nuclei was investigated, and studies of nuclear reactions induced by heavy ions were performed including experiments at the Heavy Ion Laboratory of Warsaw University. The experiments were carried out in collaboration with scientists from the Institute of Nuclear Research from Kiev, Ukraine. Proton induced reactions on zirconium were investigated theoretically by means of a multistep-direct model extended for the unbound particle - hole states. Good agreement with the experimental data was achieved. Isospin effects in multifragmentation of relativistic heavy ions were studied by the ALADIN Collaboration. Elements of a new generation detector PANDA were tested experimentally using a proton beam provided by the C-30 compact cyclotron at Swierk. Evidence of a narrow baryon state was found in a quasi - real photoproduction on the deuterium target by the HERMES Collaboration. Atomic physics: Ionisation of selected heavy elements by sulphur ions was investigated in collaboration with the Swietokrzyska Academy, Kielce. Materials research: Hydrogen release from ultrahigh molecular weight polythene was investigated by means of an α - particle beam from the Van de Graaff accelerator of our Department. Last but not least, many of our colleagues have been involved in education. Lectures on nuclear physics, accelerators, detectors used in nuclear research as well as nuclear methods applied in solid state studies for students from many high schools of Warsaw and for students of Warsaw University were given by Dr. Andrzej Korman and Dr. Lech Nowicki. Also, our Department made a significant contribution to the 7 th Science

  8. Nuclear reaction studies: Progress report

    International Nuclear Information System (INIS)

    Thaler, R.M.

    1986-01-01

    A principal focus of recent research has been the three-body problem. A great deal of effort has been devoted to the creation of a computer program to calculate physical observables in the three body problem below 1 GeV. Successful results have been obtained for the triton. Additional work concerns scattering of K + mesons from nuclei, antinucleon physics, relativistic nuclear physics and inclusive reactions

  9. Novel High Transverse Momentum Phenomena in Hadronic and Nuclear Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; /SLAC

    2009-04-10

    I discuss a number of novel phenomenological features of QCD in high transverse momentum reactions. The presence of direct higher-twist processes, where a proton is produced directly in the hard subprocess, can explain the 'baryon anomaly' - the large proton-to-pion ratio seen at RHIC in high centrality heavy ion collisions. Direct hadronic processes can also account for the deviation from leading-twist PQCD scaling at fixed x{sub T} = 2 p{sub T}/{radical}s. I suggest that the 'ridge' --the same-side long-range rapidity correlation observed at RHIC in high centrality heavy ion collisions is due to the imprint of semihard DGLAP gluon radiation from initial-state partons which have transverse momenta biased toward the trigger. A model for early thermalization of the quark-gluon medium is also outlined. Rescattering interactions from gluon-exchange, normally neglected in the parton model, have a profound effect in QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, the breakdown of the Lam-Tung relation in Drell-Yan reactions, nuclear shadowing--all leading-twist dynamics not incorporated in the light-front wavefunctions of the target computed in isolation. Anti shadowing is shown to be quark flavor specific and thus different in charged and neutral deep inelastic lepton-nucleus scattering. I also discuss other aspects of quantum effects in heavy ion collisions, such as tests of hidden color in nuclear wavefunctions, the use of diffraction to materialize the Fock states of a hadronic projectile and test QCD color transparency, and the important consequences of color-octet intrinsic heavy quark distributions in the proton for particle and Higgs production at high x{sub F}. I also discuss how the AdS/CFT correspondence between Anti-de Sitter space and conformal gauge theories allows one to compute the analytic form of frame-independent light

  10. Asian collaboration on nuclear reaction data compilation

    International Nuclear Information System (INIS)

    Aikawa, Masayuki; Furutachi, Naoya; Kato, Kiyoshi; Makinaga, Ayano; Devi, Vidya; Ichinkhorloo, Dagvadorj; Odsuren, Myagmarjav; Tsubakihara, Kohsuke; Katayama, Toshiyuki; Otuka, Naohiko

    2013-01-01

    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)

  11. Quantum mechanical theory of positron production in heavy ion collisions with nuclear contact

    International Nuclear Information System (INIS)

    Heinz, U.

    1986-01-01

    The interplay between atomic and nuclear interactions in heavy ion collisions with nuclear contact is studied. The general theoretical description is outlined and analyzed in a number of different limits (semiclassical approximation, DWBA, fully quantal description). The two most important physical mechanisms for generating atomic-nuclear interference, i.e., energy conservation and the introduction of additional phase shifts by nuclear reactions, are extracted. The resulting typical coupling matrix elements are analyzed for their relative importance in atomic and nuclear excitations. The description of nuclear influence on atomic excitations in terms of a classical time delay caused by nuclear reactions is reviewed, and its relationship to the underlying quantal character of the nuclear reaction is discussed. The theory is applied to spontaneous positron emission in supercritical heavy-ion collisions (Z/sub tot/ ≥ 173). It is shown that nuclear contact can lead to line structures in the positron energy spectra if the probability distribution for nuclear delay times caused by the contact has contributions for T ≥ 10 -19 sec. We explicitly evaluate a model where a pocket in the internuclear potential near the touching configuration leads to formation of nuclear molecules, and predict a resonance-like excitation function for the positron peak. 25 refs., 7 figs

  12. Pair production from nuclear collisions and cosmic ray transport

    International Nuclear Information System (INIS)

    Norbury, John W

    2006-01-01

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

  13. Sequential series for nuclear reactions

    International Nuclear Information System (INIS)

    Izumo, Ko

    1975-01-01

    A new time-dependent treatment of nuclear reactions is given, in which the wave function of compound nucleus is expanded by a sequential series of the reaction processes. The wave functions of the sequential series form another complete set of compound nucleus at the limit Δt→0. It is pointed out that the wave function is characterized by the quantities: the number of degrees of freedom of motion n, the period of the motion (Poincare cycle) tsub(n), the delay time t sub(nμ) and the relaxation time tausub(n) to the equilibrium of compound nucleus, instead of the usual quantum number lambda, the energy eigenvalue Esub(lambda) and the total width GAMMAsub(lambda) of resonance levels, respectively. The transition matrix elements and the yields of nuclear reactions also become the functions of time given by the Fourier transform of the usual ones. The Poincare cycles of compound nuclei are compared with the observed correlations among resonance levels, which are about 10 -17 --10 -16 sec for medium and heavy nuclei and about 10 -20 sec for the intermediate resonances. (auth.)

  14. Department of Nuclear Reaction - Overview

    International Nuclear Information System (INIS)

    Budzanowski, A.

    2000-01-01

    Full text: This year 1999 can be considered as very successful. Not only that we have published 33 papers in journals listed by the Philadelphia Institute of Science but because our hard work allowed us to obtain new and exciting results. A group of theoretical papers concerned with application of correlation among random matrices elements developed for statistical aspects of nuclear coupling into continuum to study of the collective effects in brain activity and stock market dynamics. These papers arose quite an interest and got several citations. Studies of the nonpartonic components in the nucleon structure function led to better understanding of the higher-twist effects. It was shown that inclusion of the terms of the order of 1/Q 4 improves fits to the experimental data. A review paper summarizing results on the role of the leading baryon in high energy reactions appeared in Progress on Nuclear and Particle Physics. Studies on multistep transfer reactions of light heavy ions in collaboration with the Institute of Nuclear Physics of the Ukrainian Academy of Sciences in Kiev have explained angular distributions of many reactions using the coupled channel theory. We have shown that it is possible to determine energy dependence of the optical model potential for such unstable nuclei like 8 Be. Further studies of mechanism of near threshold light meson production in collaboration with Juelich and Jagiellonian University were performed. Within COSY 10 and COSY 11 collaborations new data on the isospin symmetry breaking in pionic reactions and strange meson accompanied by hyperons emission were obtained. Together with colleagues from the Flerov Nuclear Reaction Laboratory we have started experiments with radioactive beams. Using magnetic separator COMBAS velocity distributions of isotopes with 2 ≤Z≤11 in reactions induced by 16 O on 9 Be were obtained. At the high resolution radioactive beam channel ACCULINA reactions induced by 6 He and 8 He nuclei were studied

  15. Collective phenomena in non-central nuclear collisions

    Energy Technology Data Exchange (ETDEWEB)

    Voloshin, Sergei A.; Poskanzer, Arthur M.; Snellings, Raimond

    2008-10-20

    Recent developments in the field of anisotropic flow in nuclear collision are reviewed. The results from the top AGS energy to the top RHIC energy are discussed with emphasis on techniques, interpretation, and uncertainties in the measurements.

  16. Collective phenomena in non-central nuclear collisions

    International Nuclear Information System (INIS)

    Voloshin, Sergei A.; Poskanzer, Arthur M.; Snellings, Raimond

    2008-01-01

    Recent developments in the field of anisotropic flow in nuclear collision are reviewed. The results from the top AGS energy to the top RHIC energy are discussed with emphasis on techniques, interpretation, and uncertainties in the measurements

  17. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2000-01-01

    Full text: During last year the physicists of the Department of Nuclear Reactions were involved in many experiments and projects: -Low energy nuclear reactions: For the first time a heavy ion beam from the Warsaw Cyclotron C-200 was used to investigate elastic and inelastic scattering of 12 C ions from 12 C target. The experiment is a part of a long range programme devoted to study the energy dependence of the nucleus-nucleus interactions. -Multifragmentation of relativistic heavy ions: Multifragmentation reactions induced by 12 C on different heavy targets and at different energies were studied in experiments performed at Gesellschaft fuer Schwerionenforschung by the ALADIN Collaboration. These asymmetric systems were investigated in order to study the interplay between preequilibrium and equilibrium phenomena in the nuclear liquid - gas phase transition. -The structure of nucleons: A novel, two-structure description of the Roper resonance was proposed on the basis of the α-p scattering data reanalysed by means of a T-matrix formalism. -Atomic physics: Emission of the X-rays by fast heavy ions (S, Ti, Fe) as they traverse the matter (thin carbon or other light element foil) was investigated in a series of experiments performed at University of Erlangen. It was demonstrated, that the characteristic K α X-rays emitted by a heavy ion can serve as a tool for Z-value control of the ion. -Material research: Semiconductor heterostructures were investigated by means of Rutherford Back Scattering and Channeling methods using the 2 MeV α particles from the Van de Graaff accelerator ''Lech'' at the Department. The following reports present the results and major successes which were achieved in 1999. (author)

  18. Nuclear reaction matrix and nuclear forces

    International Nuclear Information System (INIS)

    Nagata, Sinobu; Bando, Hiroharu; Akaishi, Yoshinori.

    1979-01-01

    An essentially exact method of solution is presented for the reaction- matrix (G-matrix) equation defined with the orthogonalized plane-wave intermediate spectrum for high-lying two-particle states. The accuracy is examined for introduced truncations and also in comparison with the Tsai-Kuo and Sauer methods. Properties of the G-matrix are discussed with emphasis on the relation with the saturation mechanism, especially overall saturation from light to heavy nuclei. Density and starting-energy dependences of the G-matrix are separately extracted and discussed. It is demonstrated that the triplet-even tensor component of the nuclear force is principally responsible for these dependences and hence for the saturation mechanism. In this context different nuclear potentials are used in the renormalized Brueckner calculation for energies of closed-shell nuclei in the harmonic oscillator basis. A semi-phenomenological ''two-body potential'' is devised so that it can reproduce the saturation energies and densities of nuclear matter and finite nuclei in the lowest-order Brueckner treatment. It is composed of a realistic N-N potential and two additional parts; one incorporates the three-body force effect and the other is assumed to embody higher-cluster correlations in G. The tensor component in the triplet-even state of this potential is enhanced by the three-body force effect. The G-matrix is represented in the effective local form and decomposed into central, LS and tensor components. (author)

  19. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    1999-01-01

    Full text: The Department of Nuclear Reactions had a very productive year. The following reports cover three major domains of our activities: nuclear, material and atomic physics. One of the current questions in modern nuclear physics is question of the phase transitions in nuclear matter. Our physicists, the members of the ALADIN Collaboration at Gesellschaft fuer Schwerionenforschung, participated in new experiments exploring properties of highly excited nuclear matter and the phenomenon of the liquid - gas phase transition. The experiments yielded a number of important results. Details can be found in the three short reports presented in this volume. Structure of a nucleon is another important subject of nuclear science research. In the last year energy region of Δ resonance has been investigated by means of charge exchange reaction. The experiment was performed at Laboratory National Saturne in Saclay by SPESIV-π collaboration consisting of physicist from Institute of Nuclear Physics Orsay, Niels Bohr Institute Copenhagen and from our Department. The main achievement of the experiment was evidence for a Δ - hole attraction in the spin longitudinal channel. Reactions induced by radioactive ion beams such as 6 He recently attract a lot of interest. There exist some evidences that the 6 He nucleus has a two-neutron halo structure similar to that well established for 11 Li. An analysis of 6 He + 4 He scattering data reported in this volume revealed some similarities between the loosely bound 6 Li nucleus and the neutron rich 6 He. Research in material physics has focused on two basic topics: a crystallographic model of uranium dioxide, a material currently used as a nuclear fuel and transformations of defects in GaAs crystals at low temperature. The investigations have been carried out in a wide collaboration with scientists from the University of Jena, Research Center Karlsruhe and Centre de Spectrometrie Nucleaire Orsay. Some experiments have been performed at

  20. Theoretical interpretation of high-energy nuclear collisions

    International Nuclear Information System (INIS)

    Fai, G.

    1991-07-01

    Nuclear collision data are interpreted theoretically. The nuclear equation of state is investigated with particular emphasis on momentum-dependent mean field effects. Subnucleonic degrees of freedom are invoked at high energies and densities, and a short length-scales. A nontopological soliton model for baryons is studied in which effective meson fields are generated from extended quark-antiquark pairs. The major objective of this nuclear theory project is a better understanding of the properties of strongly interacting matter on the nuclear energy scale, as manifested in high-energy heavy-ion collisions

  1. A quantum chaotic clock and damping of the coherent nuclear rotation in the 28Si+64Ni dissipative collision

    International Nuclear Information System (INIS)

    Kun, S.Y.; Vagov, A.V.

    1997-01-01

    We employ the statistical reactions with memory approach to study oscillating excitation functions in the 28 Si(E lab =120-126.75 MeV)+ 64 Ni strongly dissipative reaction and the time evolution of the collision process. The nonself-averaging of the oscillations in the excitation functions is interpreted as indication of quantum chaos and damping of the coherent nuclear rotation in dissipative heavy-ion collisions. (orig.)

  2. Pion production in relativistic collisions of nuclear drops

    International Nuclear Information System (INIS)

    Alonso, C.T.; Wilson, J.R.; McAbee, T.L.; Zingman, J.A.

    1988-09-01

    In a continuation of the long-standing effort of the nuclear physics community to model atomic nuclei as droplets of a specialized nuclear fluid, we have developed a hydrodynamic model for simulating the collisions of heavy nuclei at relativistic speeds. Our model couples ideal relativistic hydrodynamics with a new Monte Carlo treatment of dynamic pion production and tracking. The collective flow for low-energy (200 MeV/N) collisions predicted by this model compares favorably with results from earlier hydrodynamic calculations which used quite different numerical techniques. Our pion predictions at these lower energies appear to differ, however, from the experimental data on pion multiplicities. In this case of ultra-relativistic (200 GeV/N) collisions, our hydrodynamic model has produced baryonic matter distributions which are in reasonable agreement with recent experimental data. These results may shed some light on the sensitivity of relativistic collision data to the nuclear equation of state. 20 refs., 12 figs

  3. 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.

  4. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    1998-01-01

    (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 3 H(d,n) 4 He 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

  5. High energy photons production in nuclear reactions

    International Nuclear Information System (INIS)

    Nifenecker, H.; Pinston, J.A.

    1990-01-01

    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

  6. Thermal Bremsstrahlung probing nuclear multifragmentation in nucleus-nucleus collisions around the Fermi energy

    International Nuclear Information System (INIS)

    D'Enterria, D.G.

    2000-05-01

    The thermodynamical properties of nuclear matter at moderate temperatures and densities, in the vicinity of the predicted nuclear liquid-gas phase transition, are studied using as experimental probe the hard-photons (E γ > 30 MeV) emitted in nucleus-nucleus collisions. Photon and charged-particle production in four different heavy-ion reactions (Ar 36 + Au 197 , Ag 107 , Ni 58 , C 12 at 60 A*MeV) is measured exclusively and inclusively coupling the TAPS photon spectrometer with two charged-particle and intermediate-mass-fragment detectors covering nearly 4π. We confirm that Bremsstrahlung emission in first-chance (off-equilibrium) proton-neutron collisions (pnγ) is the dominant origin of hard photons. We also firmly establish the existence of a thermal radiation component emitted in second-chance proton-neutron collisions. This thermal Bremsstrahlung emission takes place in semi-central and central nucleus-nucleus reactions involving heavy targets. We exploit this observation i) to demonstrate that thermal equilibrium is reached during the reaction, ii) to establish a new thermometer of nuclear matter based on Bremsstrahlung photons, iii) to derive the thermodynamical properties of the excited nuclear sources and, in particular, to establish a 'caloric curve' (temperature versus excitation energy), and iv) to assess the time-scales of the nuclear break-up process. (author)

  7. Studies of fluctuation processes in nuclear collisions

    International Nuclear Information System (INIS)

    Ayik, S.

    1992-02-01

    This report discusses the following topics: Relativistic Boltzmann-Langevin model for heavy-ion collision; K+ production far below free neucleon-nucleon threshold and damping of collective vibrations in a memory-dependent transport model

  8. Global Λ hyperon polarization in nuclear collisions

    Science.gov (United States)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Ajitanand, N. N.; Alekseev, I.; Anderson, D. M.; Aoyama, R.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Ashraf, M. U.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Behera, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Brown, D.; Bunzarov, I.; Butterworth, J.; Caines, H.; de La Barca Sánchez, M. Calderón; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chankova-Bunzarova, N.; Chatterjee, A.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; de Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elsey, N.; Engelage, J.; Eppley, G.; Esha, R.; Esumi, S.; Evdokimov, O.; Ewigleben, J.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Federicova, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A. I.; Hamed, A.; Harlenderova, A.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, B.; Huang, X.; Huang, H. Z.; Humanic, T. J.; Huo, P.; Igo, G.; Jacobs, W. W.; Jentsch, A.; Jia, J.; Jiang, K.; Jowzaee, S.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Kocmanek, M.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulathunga, N.; Kumar, L.; Kvapil, J.; Kwasizur, J. H.; Lacey, R.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, W.; Li, Y.; Lidrych, J.; Lin, T.; Lisa, M. A.; Liu, H.; Liu, P.; Liu, Y.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, S.; Luo, X.; Ma, G. L.; Ma, L.; Ma, Y. G.; Ma, R.; Magdy, N.; Majka, R.; Mallick, D.; Margetis, S.; Markert, C.; Matis, H. S.; Meehan, K.; Mei, J. C.; Miller, Z. W.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mizuno, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nie, M.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Nonaka, T.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Ray, R. L.; Reed, R.; Rehbein, M. J.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roth, J. D.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Saur, M.; Schambach, J.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Schweid, B. R.; Seger, J.; Sergeeva, M.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, A.; Sharma, M. K.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Strikhanov, M.; Stringfellow, B.; Sugiura, T.; Sumbera, M.; Summa, B.; Sun, Y.; Sun, X. M.; Sun, X.; Surrow, B.; Svirida, D. N.; Tang, A. H.; Tang, Z.; Taranenko, A.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; van Buren, G.; van Nieuwenhuizen, G.; Vasiliev, A. N.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, Y.; Wang, F.; Wang, Y.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y. F.; Xu, Z.; Yang, Y.; Yang, Q.; Yang, C.; Yang, S.; Ye, Z.; Ye, Z.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Z.; Zhang, X. P.; Zhang, J. B.; Zhang, S.; Zhang, J.; Zhang, Y.; Zhang, J.; Zhang, S.; Zhao, J.; Zhong, C.; Zhou, L.; Zhou, C.; Zhu, X.; Zhu, Z.; Zyzak, M.

    2017-08-01

    The extreme energy densities generated by ultra-relativistic collisions between heavy atomic nuclei produce a state of matter that behaves surprisingly like a fluid, with exceptionally high temperature and low viscosity. Non-central collisions have angular momenta of the order of 1,000ћ, and the resulting fluid may have a strong vortical structure that must be understood to describe the fluid properly. The vortical structure is also of particular interest because the restoration of fundamental symmetries of quantum chromodynamics is expected to produce novel physical effects in the presence of strong vorticity. However, no experimental indications of fluid vorticity in heavy ion collisions have yet been found. Since vorticity represents a local rotational structure of the fluid, spin-orbit coupling can lead to preferential orientation of particle spins along the direction of rotation. Here we present measurements of an alignment between the global angular momentum of a non-central collision and the spin of emitted particles (in this case the collision occurs between gold nuclei and produces Λ baryons), revealing that the fluid produced in heavy ion collisions is the most vortical system so far observed. (At high energies, this fluid is a quark-gluon plasma.) We find that Λ and hyperons show a positive polarization of the order of a few per cent, consistent with some hydrodynamic predictions. (A hyperon is a particle composed of three quarks, at least one of which is a strange quark; the remainder are up and down quarks, found in protons and neutrons.) A previous measurement that reported a null result, that is, zero polarization, at higher collision energies is seen to be consistent with the trend of our observations, though with larger statistical uncertainties. These data provide experimental access to the vortical structure of the nearly ideal liquid created in a heavy ion collision and should prove valuable in the development of hydrodynamic models that

  9. High energy nuclear collisions: Theory overview

    Indian Academy of Sciences (India)

    1012 K, were deconfined and existed as a quark gluon plasma (QGP). These ideas can be tested in collisions of nuclei at ultra-relativistic energies. At the relativistic heavy-ion collider (RHIC), nuclei as heavy as gold are accelerated to an energy of 100 GeV per nucleon. A total energy of 40 TeV is available in the collision of.

  10. Catalysis of Nuclear Reactions by Electrons

    Science.gov (United States)

    Lipoglavšek, Matej

    2018-01-01

    Electron screening enhances nuclear reaction cross sections at low energies. We studied the nuclear reaction 1H(19F,αγ)16O in inverse kinematics in different solid hydrogen targets. Measured resonance strengths differed by up to a factor of 10 in different targets. We also studied the 2H(p,γ)3He fusion reaction and observed electrons emitted as reaction products instead of γ rays. In this case electron screening greatly enhances internal conversion probability.

  11. Macroscopic/microscopic simulation of nuclear reactions at intermediate energies

    International Nuclear Information System (INIS)

    Lacroix, D.; Van Lauwe, A.; Durand, D.

    2003-01-01

    An event generator, HIPSE (Heavy-Ion Phase-Space Exploration), dedicated to the description of nuclear collisions in the intermediate energy range is presented. The model simulates events for reactions close to the fusion barrier (5-10 MeV/A) up to higher energy (100 MeV/A) and it gives access to the phase-space explored during the collision. The development of HIPSE has been largely influenced by experimental observations. We have separated the reaction into 4 steps: contact, fragment formation, chemical freeze-out, and in-flight deexcitation. HIPSE will be useful for a study of various mechanisms such as neck fragmentation or multi-fragmentation

  12. High-energy nuclear reaction mechanisms - fission, fragmentation and spallation

    International Nuclear Information System (INIS)

    Kaufman, S.B.

    1987-01-01

    Measurements of the correlations in kinetic energy, mass, charge, and angle of coincident fragments formed in high-energy nuclear reactions have helped to characterize the processes of fission, fragmentation and spallation. For example, fission or fission-like two-body breakup mechanisms result in a strong angular correlation between two heavy fragments; in addition, the momentum transfer in the reaction can be deduced from the correlation. Another example is the multiplicity of light charged particles associated with a given heavy fragment, which is a measure of the violence of the collision, thus distinguishing between central and peripheral collisions. A summary of what has been learned about these processes from such studies will be given, along with some suggestions for further experiments

  13. Nuclear reaction inputs based on effective interactions

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-11-15

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

  14. Collision simulations of an exclusive ship of spent nuclear fuels

    International Nuclear Information System (INIS)

    Kitamura, Ou; Endo, Hisayoshi

    2000-01-01

    Exclusive ships for sea transport of irradiated nuclear fuels operating in Japanese territorial waters are required to be built with the special hull structure against collision. To comply with the official notice 'KAISA No. 520' issued by the Ministry of Transport, the side structure of any such exclusive ship must be designed to secure the specified energy absorption capability based on Minorsky's ship collision model. The Shipbuilding Research Association of Japan (JSRA) has studied the safety in sea transport of nuclear fuels intermittently for these several decades. Recently, the adoption of finite element method has made detailed collision analyses practicable. Since 1998, the regulation research panel No. 46 of JSRA has carried out a series of finite element collision simulations in order to estimate the realistic damage to a typical exclusive ship of spent nuclear fuels. The expected structural responses, global motions and energy absorption capabilities of both colliding and struck ships during collision were investigated. The results of the investigations have shown that the ship is very likely to withstand the collision even with one of the world's largest ship. This is due mainly to her hull structure specially strengthened beyond the crushing strength of the colliding bow structures. (author)

  15. Proceedings of the 12. International Symposium on Nuclear Physics - Heavy-Ion Collisions and Nuclear Fission - organized by the Technical University of Dresden, November 22-26, 1982 in Gaussig (GDR)

    International Nuclear Information System (INIS)

    Reif, R.; Teichert, J.

    1982-12-01

    The following problems in experimental and theoretical investigations of heavy-ion reactions and the dynamics of nuclear fission processes are discussed: (1) emission of fast light particles in heavy-ion collisions, preequilibrium effects; (2) dynamics of deep inelastic heavy-ion reactions; (3) selected topics in quasi-elastic heavy-ion collisions; and (4) collective transport theory for fission, cross sections and neutron spectra of fission. Problems of neutron induced reactions and nuclear data evaluation are also covered. (author)

  16. Department of Nuclear Reactions - Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2008-01-01

    . Jaskola joined a collaboration of many Polish institutions and performed a series of experiments at the Heavy Ion Laboratory of Warsaw University devoted to a study of cell survival after irradiation by ions from the Warsaw Cyclotron. Finally, I would like to warmly welcome drs H.P. Morsch and N. Keeley who joined us last year. Dr Morsch is collaborating with Assoc. Prof. P. Zupranski on a multi-gluon field approach within Quantum Chromodynamics. Dr Keeley's interest is in low energy nuclear reactions. I would also like to welcome our new PhD students, Ms I. Strojek, Mr l. Standylo and Mr Shaaban Abd El Aal. With Mr Abd El Aal we are opening a new field of applications of nuclear methods, studying ancient Egyptian frescos by means of proton induced X-ray emission (PIXE). As every year, apart from purely scientific activities, a few of our colleagues have been involved in education, giving lectures to students from highs Schools in Warsaw and to students of Warsaw University. (author)

  17. Photon production in relativistic nuclear collisions at SPS and RHIC energies

    CERN Document Server

    Turbide, S; Rapp, R; 10.1142/S0217751X0402258X

    2004-01-01

    Chiral Lagrangians are used to compute the production rate of photons from the hadronic phase of relativistic nuclear collisions. Special attention is paid to the role of the a/sub 1/ pseudovector. Calculations that include strange meson reactions, form factors, the use of consistent vector spectral densities, the emission from a quark-gluon plasma, and primordial nucleon-nucleon collisions reproduce the photon spectra measured at the Super Proton Synchrotron (SPS). Some predictions for the Relativistic Heavy Ion Collider (RHIC) are made.

  18. Origin of the finite nuclear spin and its effect in intermediate energy heavy ion collisions

    International Nuclear Information System (INIS)

    Zhang Guoqiang; Cao Xiguang; Fu Yao

    2012-01-01

    The heavy-ion phase-space exploration (HIPSE) model is used to discuss the origin of the nuclear spin in intermediate energy heavy-ion collision (HIC). The spin of maximal projectile-like fragment is found to depend strongly on impact parameter of a reaction system,while it relates weakly to the collision violence. Some interesting multi-fragmentation phenomena related to the spin are shown. We also found that the excitation energy in the de-excitation stage plays a robust role at the de-excitation stage in HIC. (authors)

  19. Nuclear Reaction Data File for Astrophysics (NRDF/A) in Hokkaido University Nuclear Reaction Data Center

    International Nuclear Information System (INIS)

    Kato, Kiyoshi; Kimura, Masaaki; Furutachi, Naoya; Makinaga, Ayano; Togashi, Tomoaki; Otuka, Naohiko

    2010-01-01

    The activities of the Japan Nuclear Reaction Data Centre is explained. The main task of the centre is data compilation of Japanese nuclear reaction data in collaboration of the International Network of Nuclear Reaction Data Centres. As one of recent activities, preparation of a new database (NRDF/A) and evaluation of astronuclear reaction data are reported. Collaboration in the nuclear data activities among Asian countries is proposed.

  20. The heavy-ion total reaction cross-section and nuclear transparancy

    International Nuclear Information System (INIS)

    Rego, R.A.; Hussein, M.S.

    1982-10-01

    The total reaction cross section of heavy ions at intermediate energies is discussed. The special role played by the individual nucleon-nucleon collisions in determining the nuclear transparancy is analysed. Several competing effects arising from the nuclear and Coulomb interactions between the two ions are found to be important in determing σ sub(R) at lower energies. (Author) [pt

  1. The heavy-ion total reaction cross-section and nuclear transparency

    International Nuclear Information System (INIS)

    Rego, R.A.; Hussein, M.S.

    1982-01-01

    The total reaction cross section of heavy ions at intermediate energies is discussed. The special role played by the individual nucleon-nucleon collisions in determining the nuclear transparency is analysed. Several competing effects arising from the nuclear and Coulomb interactions between the two ions are found to be important in determining σ(sub R) at lower energies. (Author) [pt

  2. The nuclear reaction model code MEDICUS

    International Nuclear Information System (INIS)

    Ibishia, A.I.

    2008-01-01

    The new computer code MEDICUS has been used to calculate cross sections of nuclear reactions. The code, implemented in MATLAB 6.5, Mathematica 5, and Fortran 95 programming languages, can be run in graphical and command line mode. Graphical User Interface (GUI) has been built that allows the user to perform calculations and to plot results just by mouse clicking. The MS Windows XP and Red Hat Linux platforms are supported. MEDICUS is a modern nuclear reaction code that can compute charged particle-, photon-, and neutron-induced reactions in the energy range from thresholds to about 200 MeV. The calculation of the cross sections of nuclear reactions are done in the framework of the Exact Many-Body Nuclear Cluster Model (EMBNCM), Direct Nuclear Reactions, Pre-equilibrium Reactions, Optical Model, DWBA, and Exciton Model with Cluster Emission. The code can be used also for the calculation of nuclear cluster structure of nuclei. We have calculated nuclear cluster models for some nuclei such as 177 Lu, 90 Y, and 27 Al. It has been found that nucleus 27 Al can be represented through the two different nuclear cluster models: 25 Mg + d and 24 Na + 3 He. Cross sections in function of energy for the reaction 27 Al( 3 He,x) 22 Na, established as a production method of 22 Na, are calculated by the code MEDICUS. Theoretical calculations of cross sections are in good agreement with experimental results. Reaction mechanisms are taken into account. (author)

  3. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2005-01-01

    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, 14 C. 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

  4. Heavy Quark and Quarkonium Transport in High Energy Nuclear Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Kai [Physics Department, Tsinghua University and Collaborative Innovation Center of Quantum Matter, Beijing 100084 (China); Institute for Theoretical Physics, Johann Wolfgang Goethe-University, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany); Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main (Germany); Dai, Wei [Physics Department, Tsinghua University and Collaborative Innovation Center of Quantum Matter, Beijing 100084 (China); Xu, Nu [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan 430079 (China); Zhuang, Pengfei [Physics Department, Tsinghua University and Collaborative Innovation Center of Quantum Matter, Beijing 100084 (China)

    2016-12-15

    The strong interaction between heavy quarks and the quark gluon plasma makes the open and hidden charm hadrons be sensitive probes of the deconfinement phase transition in high energy nuclear collisions. Both the cold and hot nuclear matter effects change with the colliding energy and significantly influence the heavy quark and charmonium yield and their transverse momentum distributions. The ratio of averaged quarkonium transverse momentum square and the elliptic flow reveal the nature of the QCD medium created in heavy ion collisions at SPS, RHIC and LHC energies.

  5. Heavy Quark and Quarkonium Transport in High Energy Nuclear Collisions

    International Nuclear Information System (INIS)

    Zhou, Kai; Dai, Wei; Xu, Nu; Zhuang, Pengfei

    2016-01-01

    The strong interaction between heavy quarks and the quark gluon plasma makes the open and hidden charm hadrons be sensitive probes of the deconfinement phase transition in high energy nuclear collisions. Both the cold and hot nuclear matter effects change with the colliding energy and significantly influence the heavy quark and charmonium yield and their transverse momentum distributions. The ratio of averaged quarkonium transverse momentum square and the elliptic flow reveal the nature of the QCD medium created in heavy ion collisions at SPS, RHIC and LHC energies.

  6. Shape nuclei and nuclear reactions

    International Nuclear Information System (INIS)

    Yushkov, A.V.

    1975-01-01

    Experimental methods for obtaining the nucleus shape parameters are reviewed throughout the period of 1955-1975. Spatial properties of a nucleus, which can be directly or indirectly measured, are determined. They include: parameters of nucleus localization in space; parameters characterizing the nucleus nonsphericity; parameters of the nucleus nonaxiality. Dimensional parameters of a nucleus, namely, radius R and surface ΔR are derived from electron scattering. The deformation sign is indirectly obtained in the experiments. Parameters of the nucleus shape, namely, the sign and magnitude of nuclear deformation are derived from the mean energy proton scattering by a coupled channels method. The only direct way of deriving the nucleus surface deformation signs is the method of the Blaire phase shift. Results on scattering of electrons, protons, and α-particles on light and medium nuclei are reported. Data on the nucleus shape can be also obtained from reactions with heavy ions. A difference between strong absorptions of incident particles of high and average energy by a nucleus is noted. Numerous diagrams illustrate experimental and theoretical results

  7. Nuclear structure in deep-inelastic reactions

    International Nuclear Information System (INIS)

    Rehm, K.E.

    1986-01-01

    The paper concentrates on recent deep inelastic experiments conducted at Argonne National Laboratory and the nuclear structure effects evident in reactions between super heavy nuclei. Experiments indicate that these reactions evolve gradually from simple transfer processes which have been studied extensively for lighter nuclei such as 16 O, suggesting a theoretical approach connecting the one-step DWBA theory to the multistep statistical models of nuclear reactions. This transition between quasi-elastic and deep inelastic reactions is achieved by a simple random walk model. Some typical examples of nuclear structure effects are shown. 24 refs., 9 figs

  8. Statistical theory of precompound nuclear reactions

    International Nuclear Information System (INIS)

    Nishioka, H.

    1986-01-01

    The purpose of the paper is to show the application of the Grassmann-integration method (or the graded-symmetry method) to a pre-equilibrium process in nuclear reactions. The Grassmann-integration method for random systems was first introduced by Efetov and later largely extended and applied to nuclear physics by Verbaarschot, Weidenmuller and Zirnbauer (referred to as VWZ). They have applied it to the equilibrium nuclear reactions; namely; the compound-nucleus reactions. It will be shown in this paper that this method is also applicable to non-equilibrium nuclear reactions. Applying this method to precompound nuclear reactions, the authors have obtained the same expression of the cross-section as Agassi, Weidenmuller and Mantzouranis (referred to as AWM) in the weak-coupling limit. In the general case their results show an important modification to AWM

  9. Angular-momentum transport in nuclear collisions

    International Nuclear Information System (INIS)

    Wolschin, G.; Ayik, S.; Noerenberg, W.

    1978-01-01

    Among the various relaxation processes that can be observed in heavy-ion collisions, the dissipation of relative angular momentum into intrinsic angular momentum of the fragments attracts increasing attention. Here we present a transport theoretical description of angular-momentum and mass transport that allows for a transparent interpretation of the data. (orig.) [de

  10. Nuclear reaction database on Meme Media

    International Nuclear Information System (INIS)

    Ohbayashi, Yoshihide; Masui, Hiroshi; Aoyama, Shigeyoshi; Kato, Kiyoshi; Chiba, Masaki

    2000-01-01

    We have developed the system of charged particle nuclear reaction data (CPND) on the IntelligentPad architecture. We called the system CONTIP, which is an abbreviation of 'Creative, Cooperative and Cultural Objects for Nuclear data and Tools'. NRDF (Nuclear Reaction Data File), which is a kind of CPND compilation, is applied as an application example. Although CONTIP is currently applied to NRDF, the framework can be generalized to use the other nuclear database. We will develop CONTIP to give the framework for effective utilization of nuclear data. (author)

  11. Pre-equilibrium nuclear reactions: An introduction to classical and quantum-mechanical models

    International Nuclear Information System (INIS)

    Koning, A.J.; Akkermans, J.M.

    1999-01-01

    In studies of light-ion induced nuclear reactions one distinguishes three different mechanisms: direct, compound and pre-equilibrium nuclear reactions. These reaction processes can be subdivided according to time scales or, equivalently, the number of intranuclear collisions taking place before emission. Furthermore, each mechanism preferably excites certain parts of the nuclear level spectrum and is characterized by different types of angular distributions. This presentation includes description of the classical, exciton model, semi-classical models, with some selected results, and quantum mechanical models. A survey of classical versus quantum-mechanical pre-equilibrium reaction theory is presented including practical applications

  12. Putting Reaction Rates and Collision Theory in the Hands of Your Students.

    Science.gov (United States)

    Evenson, Andy

    2002-01-01

    Describes a simulation that can be used to give concrete analogies of collision theory and the factors that affect reaction rates including temperature, concentration, catalyst, and molecular orientation. The simulation works best if done as an introduction to the concepts to help prevent misconceptions about reaction rates and collision theory.…

  13. Probing phase transitions via energetic nuclear collisions

    International Nuclear Information System (INIS)

    Lukacs, B.; Csernai, L.P.

    1983-07-01

    The possible effects of the nucleon-quark phase transition on the dynamics of heavy ion collisions are discussed. It is shown that the formation of the quark phase can be expected at recent experiments. Nevertheless, the compressibility of the two-phase mixture remains relatively low, thus the quark phase remains limited in both space and time, and the observables are not strongly affected. (author)

  14. Probing the nuclear symmetry energy with heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    De Filippo E.

    2015-01-01

    Full Text Available Heavy ion collisions (HIC have been widely used to extract the parametrization of symmetry energy term of nuclear equation of state as a function of barionic density. HIC in fact are a unique tool in terrestrial laboratories to explore the symmetry energy around the saturation density (ρ0 = 0.16fm−3 from sub-saturation densities (Fermi energies towards compressed nuclear matter (ρ > 2 − 3ρ0 that can be reached at relativistic energies, as a function of different conditions of temperature, mass asymmetry and isospin. One of the main study at present is to reach a coherent description of EOS of asymmetric nuclear matter from heavy ion collisions of stable and exotic nuclei, nuclear structure studies and astrophysical observations. In this work an overview of the current status of the research is shortly reviewed together with new perspectives aimed to reduce the present experimental and theoretical uncertainties.

  15. Deexcitation processes in nuclear reactions

    International Nuclear Information System (INIS)

    Porile, N.T.

    1992-09-01

    During the past year, our research program has involved continuing analysis of Fermilab E-735, search for quark-gluon plasma (QGP) in bar p-p collisions; continuing study of target fragments produced in the interaction of copper with intermediate-energy heavy ions; an exclusive study of multifragmentation using reverse kinematics at the Bevalac; and detector development for the STAR detector at RHIC

  16. Low Energy Nuclear Reactions: 2007 Update

    Science.gov (United States)

    Krivit, Steven B.

    2007-03-01

    This paper presents an overview of low energy nuclear reactions, a subset of the field of condensed matter nuclear science. Condensed matter nuclear science studies nuclear effects in and/or on condensed matter, including low energy nuclear reactions, an entirely new branch of science that gained widespread attention and notoriety beginning in 1989 with the announcement of a previously unrecognized source of energy by Martin Fleischmann and Stanley Pons that came to be known as cold fusion. Two branches of LENR are recognized. The first includes a set of reactions like those observed by Fleischmann and Pons that use palladium and deuterium and yield excess heat and helium-4. Numerous mechanisms have been proposed to explain these reactions, however there is no consensus for, or general acceptance of, any of the theories. The claim of fusion is still considered speculative and, as such, is not an ideal term for this work. The other branch is a wide assortment of nuclear reactions that may occur with either hydrogen or deuterium. Anomalous nuclear transmutations are reported that involve light as well as heavy elements. The significant questions that face this field of research are: 1) Are LENRs a genuine nuclear reaction? 2) If so, is there a release of excess energy? 3) If there is, is the energy release cost-effective?

  17. Evaluation of electon and nuclear bremsstrahlung in heavy ion collisions

    International Nuclear Information System (INIS)

    Gippner, P.

    1975-01-01

    The detection of quasimolecular X-ray continua provides the possibility of investigating the electron shells of quasimolecules transiently formed during adiabatic heavy ion-atomic collision. The contribution of the electron and nuclear bremsstrahlung to quasimolecular X-ray continua observed in bombarding various targets with 65 and 96 MeV Nb ions were estimated

  18. PARTON SATURATION, PRODUCTION, AND EQUILIBRATION IN HIGH ENERGY NUCLEAR COLLISIONS

    International Nuclear Information System (INIS)

    VENUGOPALAN, R.

    1999-01-01

    Deeply inelastic scattering of electrons off nuclei can determine whether parton distributions saturate at HERA energies. If so, this phenomenon will also tell us a great deal about how particles are produced, and whether they equilibrate, in high energy nuclear collisions

  19. Novel Role of Superfluidity in Low-Energy Nuclear Reactions.

    Science.gov (United States)

    Magierski, Piotr; Sekizawa, Kazuyuki; Wlazłowski, Gabriel

    2017-07-28

    We demonstrate, within symmetry unrestricted time-dependent density functional theory, the existence of new effects in low-energy nuclear reactions which originate from superfluidity. The dynamics of the pairing field induces solitonic excitations in the colliding nuclear systems, leading to qualitative changes in the reaction dynamics. The solitonic excitation prevents collective energy dissipation and effectively suppresses the fusion cross section. We demonstrate how the variations of the total kinetic energy of the fragments can be traced back to the energy stored in the superfluid junction of colliding nuclei. Both contact time and scattering angle in noncentral collisions are significantly affected. The modification of the fusion cross section and possibilities for its experimental detection are discussed.

  20. Outline of cold nuclear fusion reaction

    International Nuclear Information System (INIS)

    Tachikawa, Enzo

    1991-01-01

    In 2010, as the total supply capacity of primary energy, 666 million liter is anticipated under the measures of thorough energy conservation. The development of energy sources along the energy policy based on environment preservation, safety, the quantity of resources and economy is strongly demanded. The nuclear power generation utilizing nuclear fission has been successfully carried out. As the third means of energy production, the basic research and technical development have been actively advanced on the energy production utilizing nuclear fusion reaction. The main object of the nuclear fusion research being advanced now is D-D reaction and D-T reaction. In order to realize low temperature nuclear fusion reaction, muon nuclear fusion has been studied so far. The cold nuclear fusion reaction by the electrolysis of heavy water has been reported in 1989, and its outline is ixplained in this report. The trend of the research on cold nuclear fusion is described. But the possibility of cold nuclear fusion as an energy source is almost denied. (K.I.)

  1. Nuclear fission, chain reaction and criticality

    International Nuclear Information System (INIS)

    Reuss, Paul

    2016-01-01

    Criticality is, notably for nuclear reactors, the status which separates the case of a fission chain reaction which inexorably decays, from that of a reaction which grows faster and faster until a counter-reaction occurs. If this status is an objective in nuclear reactors, it must not be reached or exceeded in any case in other types of installations in which fissile materials are handled (fabrication, transports, nuclear fuel processing). The author proposes an insight into this notion of criticality, discusses elements of neutron science which allow the multiplication factor to be assessed, analyses accidental scenarios which may happen, and presents associated experiments and computation codes

  2. International Network of Nuclear Reaction Data Centres

    International Nuclear Information System (INIS)

    Otsuka, Naohiko; Dunaeva, Svetlana

    2010-11-01

    The activities of fourteen nuclear data centres are summarized, and their cooperation under the auspices of the International Atomic Energy Agency is described. Each of the centres provides coverage for different geographical zones and/or specific types of nuclear data, thus together providing a complete service for users worldwide. The International Network of Nuclear Reaction Data Centres (NRDC) was established with the objective of providing nuclear physics databases that are required for nuclear technology (encompassing energy and non-energy applications) by coordinating the collection, compilation and dissemination of nuclear data on an international scale. (author)

  3. Hydrogen release from irradiated elastomers measured by Nuclear Reaction Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jagielski, J., E-mail: jacek.jagielski@itme.edu.pl [Institute for Electronic Materials Technology, Wolczynska 133, 01-926 Warszawa (Poland); National Centre for Nuclear Research, A. Soltana 7, 05-400 Swierk/Otwock (Poland); Ostaszewska, U. [Institute for Engineering of Polymer Materials & Dyes, Division of Elastomers & Rubber Technology, Harcerska 30, 05-820 Piastow (Poland); Bielinski, D.M. [Technical University of Lodz, Institute of Polymer & Dye Technology, Stefanowskiego 12/16, 90-924 Lodz (Poland); Grambole, D. [Institute of Ion Beam Physics and Materials Research, Helmholtz Zentrum Dresden Rossendorf, PO Box 51 01 19, D-01314 Dresden (Germany); Romaniec, M.; Jozwik, I.; Kozinski, R. [Institute for Electronic Materials Technology, Wolczynska 133, 01-926 Warszawa (Poland); Kosinska, A. [National Centre for Nuclear Research, A. Soltana 7, 05-400 Swierk/Otwock (Poland)

    2016-03-15

    Ion irradiation appears as an interesting method of modification of elastomers, especially friction and wear properties. Main structural effect caused by heavy ions is a massive loss of hydrogen from the surface layer leading to its smoothening and shrinking. The paper presents the results of hydrogen release from various elastomers upon irradiation with H{sup +}, He{sup +} and Ar{sup +} studied by using Nuclear Reaction Analysis (NRA) method. The analysis of the experimental data indicates that the hydrogen release is controlled by inelastic collisions between ions and target electrons. The last part of the study was focused on preliminary analysis of mechanical properties of irradiated rubbers.

  4. 1-3 Nuclear In-medium Effects of Strange Particles in Proton-nucleus Collisions

    Institute of Scientific and Technical Information of China (English)

    Feng; Zhaoqing[1

    2014-01-01

    Extraction of the in-medium properties of strange particles from heavy-ion collisions is very complicated, since he nuclear density varies in the evolution of nucleus-nucleus collisions. To avoid the uncertainties of the baryon ensities during the stage of strange particle production, one can investigate proton-nucleus collisions where the uclear density is definite around the saturation density. Dynamics of strange particles produced in the protoninduced uclear the reactions near the threshold energies has been investigated within the Lanzhou quantum olecular dynamics (LQMD) transport model. The in-medium modifications on particle production in densenuclear matter are considered through the corrections to the elementary cross sections via the effective mass and he mean-field potentials[1].

  5. Nuclear reaction database on Meme Media

    Energy Technology Data Exchange (ETDEWEB)

    Ohbayashi, Yoshihide; Masui, Hiroshi [Meme Media Laboratory, Hokkaido University, Sapporo, Hokkaido (Japan); Aoyama, Shigeyoshi [Information Processing Center, Kitami Institute of Technology, Kitami, Hokkaido (Japan); Kato, Kiyoshi [Division of Physics, Graduate School of Science, Hokkaido Univ., Sapporo, Hokkaido (Japan); Chiba, Masaki [Division of Social Information, Sapporo Gakuin University, Ebetsu, Hokkaido (Japan)

    2000-03-01

    We have developed the system of charged particle nuclear reaction data (CPND) on the IntelligentPad architecture. We called the system CONTIP, which is an abbreviation of 'Creative, Cooperative and Cultural Objects for Nuclear data and Tools'. NRDF (Nuclear Reaction Data File), which is a kind of CPND compilation, is applied as an application example. Although CONTIP is currently applied to NRDF, the framework can be generalized to use the othernuclear database. We will develop CONTIP to give the framework for effective utilization of nuclear data. (author)

  6. Physics of Nuclear Collisions at High Energy

    Energy Technology Data Exchange (ETDEWEB)

    Hwa, Rudolph C. [Univ. of Oregon, Eugene, OR (United States)

    2012-05-01

    A wide range of problems has been investigated in the research program during the period of this grant. Although the major effort has been in the subject of heavy-ion collisions, we have also studied problems in biological and other physical systems. The method of analysis used in reducing complex data in multiparticle production to simple descriptions can also be applied to the study of complex systems of very different nature. Phase transition is an important phenomenon in many areas of physics, and for heavy-ion collisions we study the fluctuations of multiplicities at the critical point. Human brain activities as revealed in EEG also involve fluctuations in time series, and we have found that our experience enables us to find the appropriate quantification of the fluctuations in ways that can differentiate stroke and normal subjects. The main topic that characterizes the research at Oregon in heavy-ion collisions is the recombination model for the treatment of the hadronization process. We have avoided the hydrodynamical model partly because there is already a large community engaged in it, but more significantly we have found the assumption of rapid thermalization unconvincing. Recent results in studying LHC physics lead us to provide more evidence that shower partons are very important even at low p_T, but are ignored by hydro. It is not easy to work in an environment where the conventional wisdom regards our approach as being incorrect because it does not adhere to the standard paradigm. But that is just what a vibrant research community needs: unconventional approach may find evidences that can challenge the orthodoxy. An example is the usual belief that elliptic flow in fluid dynamics gives rise to azimuthal anisotropy. We claim that it is only sufficient but not necessary. With more data from LHC and more independent thinkers working on the subject what is sufficient as a theory may turn out to be incorrect in reality. Another area of investigation that

  7. Nuclear excitations and reaction mechanisms: Progress report

    International Nuclear Information System (INIS)

    Fallieros, S.; Levin, F.S.

    1988-01-01

    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

  8. Multiparticle Production in Particle and Nuclear Collisions. I

    Science.gov (United States)

    Kanki, T.; Kinoshita, K.; Sumiyoshi, H.; Takagi, F.

    The dominant phenomenon in high-energy particle and nuclear collisions is multiple production of hadrons. This had attracted may physicists in 1950's, the period of the first remarkable development of particle physics. Multiparticle production was already observed in cosmic-ray experiments and expected to be explained as a natural consequence of the strong Yukawa interaction. Statistical and hydrodynamical models were then proposed by Fermi, Landau and others. These theories are still surviving even today as a prototype of modern ``fire-ball'' models. After twenty years, a golden age came in this field of physics. It was closely related to the rapid development of accelerator facilities, especially, the invention of colliding-beam machines which yield high enough center-of-mass energies for studying reactions with high multiplicity. Abundant data on final states of multiparticle production have been accumulated mainly by measuring inclusive cross sections and multiplicity distributions. In super high-energy bar{p}p collisions at CERN S pmacr pS Collider, we confirmed the increasing total cross section and found violations of many scaling laws which seemed to be valid at lower energies. This suggests a fundamental complexity of the multiparticle phenomena and offers new materials for further development of theoretical investigations. In the same period, studies of constituent (quark-gluon) structure of hadrons had also been develped. Nowadays, pysicists believe that the quantum chromodynamics (QCD) is the fundamental law of the hadronic world. Multiparticle dynamics should also be described by QCD. We have known that the hard-jet phenomena are well explained by the perturbative QCD. On the other hand, the soft processes are considered to be non-perturbative phenomena which have not yet been solved, and related to the mechanism of the color confinement and formation of strings or color-flux tubes. Multiparticle production would offer useful information on this

  9. Multiparticle Production in Particle and Nuclear Collisions. II

    Science.gov (United States)

    Kanki, T.; Kinoshita, K.; Sumiyoshi, H.; Takagi, F.

    The dominant phenomenon in high-energy particle and nuclear collisions is multiple production of hadrons. This had attracted may physicists in 1950's, the period of the first remarkable development of particle physics. Multiparticle production was already observed in cosmic-ray experiments and expected to be explained as a natural consequence of the strong Yukawa interaction. Statistical and hydrodynamical models were then proposed by Fermi, Landau and others. These theories are still surviving even today as a prototype of modern ``fire-ball'' models. After twenty years, a golden age came in this field of physics. It was closely related to the rapid development of accelerator facilities, especially, the invention of colliding-beam machines which yield high enough center-of-mass energies for studying reactions with high multiplicity. Abundant data on final states of multiparticle production have been accumulated mainly by measuring inclusive cross sections and multiplicity distributions. In super high-energy bar{p}p collisions at CERN S pmacr pS Collider, we confirmed the increasing total cross section and found violations of many scaling laws which seemed to be valid at lower energies. This suggests a fundamental complexity of the multiparticle phenomena and offers new materials for further development of theoretical investigations. In the same period, studies of constituent (quark-gluon) structure of hadrons had also been develped. Nowadays, pysicists believe that the quantum chromodynamics (QCD) is the fundamental law of the hadronic world. Multiparticle dynamics should also be described by QCD. We have known that the hard-jet phenomena are well explained by the perturbative QCD. On the other hand, the soft processes are considered to be non-perturbative phenomena which have not yet been solved, and related to the mechanism of the color confinement and formation of strings or color-flux tubes. Multiparticle production would offer useful information on this

  10. Exclusive observables from a statistical simulation of energetic nuclear collisions

    International Nuclear Information System (INIS)

    Fai, G.

    1983-01-01

    Exclusive observables are calculated in the framework of a statistical model for medium-energy nuclear collisions. The collision system is divided into a few (participant/spectator) sources, that are assumed to disassemble independently. Sufficiently excited sources explode into pions, nucleons, and composite, possibly particle unstable, nuclei. The different final states compete according to their microcanonical weight. Less excited sources, and the unstable explosion products, deexcite via light-particle evaporation. The model has been implemented as a Monte Carlo computer code that is sufficiently efficient to permit generation of large event samples. Some illustrative applications are discussed. (author)

  11. Nuclear alignment following compound nucleus reactions

    International Nuclear Information System (INIS)

    Butler, P.A.; Nolan, P.J.

    1981-01-01

    A procedure for calculating the alignment of a nuclear state populated by a compound nucleus reaction is given and used to investigate how alignment varies for different types of population mechanisms. The calculations are compared to both predictions of Gaussian models for the state population distribution and to experimental data, for a variety of types of nuclear reactions. The treatment of alignment in the analysis of γ-ray angular distribution is discussed. (orig.)

  12. 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)

  13. Statistical theory of neutron nuclear reactions

    International Nuclear Information System (INIS)

    Moldauer, P.A.

    1980-01-01

    The statistical theory of average neutron nucleus reaction cross sections is reviewed with emphasis on the justification of the Hauser Feshbach formula and its modifications for situations including isolated compound nucleus resonances, overlapping and interfering resonances, the competition of compound and direct reactions, and continuous treatment of residual nuclear states. (author)

  14. Statistical theory of neutron nuclear reactions

    International Nuclear Information System (INIS)

    Moldauer, P.A.

    1978-02-01

    The statistical theory of average neutron nucleus reaction cross sections is reviewed with emphasis on the justification of the Hauser Feshbach formula and its modifications for situations including isolated compound nucleus resonances, overlapping and interfering resonances, the competition of compound and direct reactions, and continuous treatment of residual nuclear states

  15. Statistical theory of neutron nuclear reactions

    International Nuclear Information System (INIS)

    Moldauer, P.A.

    1975-01-01

    The statistical theory of average neutron nucleus reaction cross sections is reviewed with emphasis on the justification of the Hauser Feshbach formula and its modifications for situations including isolated compound nucleus resonances, overlapping and interfering resonances, the competition of compound and direct reactions, and continuous treatment of residual nuclear states. 3 figures

  16. Transverse Characteristics of Hadron Production in Elementary and Nuclear Collisions at the CERN SPS Energies

    CERN Document Server

    AUTHOR|(CDS)2076476; Bialkowska, H

    2004-01-01

    A comprehensive study of transverse phenomena at CERN-SPS energies has been performed using data collected by the NA49 experiment. Results on p, p, pi+ and pi- production in elementary hadronic interactions (p + p, pi+ +p and pi- + p) as well as in nuclear collisions (centrality-defined p + Pb, C + C, Si + Si And Pb + Pb) are presented. The dependence of transverse momentum spectra, and in particular the - xF correlations, on particle species, collision energy, size and structure of the colliding objects has been investigated. Particle composition, in terms of the nuclear modification factors RpA (pT) for different xF regions – and particle ratios, has been also studied. The whole set of experimental data puts strong constraints on theoretical models aiming at the description of hadron production in the studied reactions.

  17. High energy nuclear collisions in the few GeV/nucleon region: projectile and target fragmentation

    International Nuclear Information System (INIS)

    Schroeder, L.S.

    1980-06-01

    A general review of nucleon-nucleus and nucleus-nucleus collisions for incident energies <10 GeV/nucleon is presented. The division of these interactions into peripheral and central collisions is briefly discussed. Subjects treated include the following: target and projectile fragmentation systematics, production of exotic nuclear fragments, studies of multiparticle final states, total cross section measurements, results from an experiment that indicate the production of projectile fragments with an anomalously short reaction mean free path, high-energy particle production at backward angles beyond simple N-N kinematic limits, and recent results on backward particle emission in studies with the Berkeley streamer chamber. Both the particle and nuclear physics aspects that are present are considered. A brief discussion of future trends in this energy range ends the presentation. 65 references, 37 figures

  18. Nuclear reactions in ultra-magnetized supernovae

    International Nuclear Information System (INIS)

    Kondratyev, V.N.

    2002-06-01

    The statistical model is employed to investigate nuclear reactions in ultrastrong magnetic fields relevant for supernovae and neutron stars. For radiative capture processes the predominant mechanisms are argued to correspond to modifications of nuclear level densities, and γ-transition energies due to interactions of the field with magnetic moments of nuclei. The density of states reflects the nuclear structure and results in oscillations of reaction cross sections as a function of field strength, while magnetic interaction energy enhances radiative neutron capture process. Implications in the synthesis of r-process nuclei in supernova site are discussed. (author)

  19. Verification of cold nuclear fusion reaction, (1)

    International Nuclear Information System (INIS)

    Yoshida, Zenko; Aratono, Yasuyuki; Hirabayashi, Takakuni

    1991-01-01

    Can cold nuclear fusion reaction occur as is expected? If it occurs, what extent is its reaction probability? At present after 2 years elapsed since its beginning, the clear solution of these questions is not yet obtained. In many reaction systems employing different means, the experiments to confirm the cold nuclear fusion reaction have been attempted. In order to confirm that the nuclear fusion reaction of deuterium mutually has occurred, the neutrons, He-3, protons, tritium or generated heat, which were formed by the reaction and released from the system, are measured. Since it is considered that the frequency of the occurrence at normal temperature of the reaction is very low, it is necessary to select the most suitable method upon evaluating the limit of detection peculiar to the measuring methods. The methods of measuring neutrons, protons, gamma ray and generated heat, and the reaction systems by electrolytic process and dry process are explained. The detection of plural kinds of the reaction products and the confirmation of synchronism of signals are important. (K.I.)

  20. Induced isospin mixing in direct nuclear reactions

    International Nuclear Information System (INIS)

    Lenske, H.

    1979-07-01

    The effect of charge-dependent interactions on nuclear reactions is investigated. First, a survey is given on the most important results concerning the charge dependence of the nucleon-nucleon interaction. The isospin symmetry and invariance principles are discussed. Violations of the isospin symmetry occuring in direct nuclear reactions are analysed using the soupled channel theory, the folding model and microscopic descriptions. Finally, induced isospin mixing in isospin-forbidden direct reactions is considered using the example of the inelastic scattering of deuterons on 12 C. (KBE)

  1. Nuclear chain reaction: forty years later

    International Nuclear Information System (INIS)

    Sachs, R.G.

    1984-01-01

    The proceedings from a 1982 symposium 40 years after the first controlled nuclear chain reaction took place in Chicago covers four sessions and public discussion. The session covered the history of the chain reaction; peaceful uses in technology, medicine, and biological science; peaceful uses in power generation; and nuclear weapons control. Among the speakers were Eugene Wigner, Glenn Seaborg, Alvin Weinberg, and others who participated in the first chain reaction experiments. The proceedings reflect differences of opinion among the scientists as well as the general public. References, slides, and tables used to illustrate the individual talks are included with the papers

  2. Matter in extremis: Ultrarelativistic nuclear collisions at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Peter; Wang, Xin-Nian

    2004-08-20

    We review the physics of nuclear matter at high energy density and the experimental search for the Quark-Gluon Plasma at the Relativistic Heavy Ion Collider (RHIC). The data obtained in the first three years of the RHIC physics program provide several lines of evidence that a novel state of matter has been created in the most violent, head-on collisions of Au nuclei at {radical}s = 200 GeV. Jet quenching and global measurements show that the initial energy density of the strongly interacting medium generated in the collision is about two orders of magnitude larger than that of cold nuclear matter, well above the critical density for the deconfinement phase transition predicted by lattice QCD. The observed collective flow patterns imply that the system thermalizes early in its evolution, with the dynamics of its expansion consistent with ideal hydrodynamic flow based on a Quark-Gluon Plasma equation of state.

  3. Matter in extremis: Ultrarelativistic nuclear collisions at RHIC

    International Nuclear Information System (INIS)

    Jacobs, Peter; Wang, Xin-Nian

    2004-01-01

    We review the physics of nuclear matter at high energy density and the experimental search for the Quark-Gluon Plasma at the Relativistic Heavy Ion Collider (RHIC). The data obtained in the first three years of the RHIC physics program provide several lines of evidence that a novel state of matter has been created in the most violent, head-on collisions of Au nuclei at √s = 200 GeV. Jet quenching and global measurements show that the initial energy density of the strongly interacting medium generated in the collision is about two orders of magnitude larger than that of cold nuclear matter, well above the critical density for the deconfinement phase transition predicted by lattice QCD. The observed collective flow patterns imply that the system thermalizes early in its evolution, with the dynamics of its expansion consistent with ideal hydrodynamic flow based on a Quark-Gluon Plasma equation of state

  4. Nuclear suppression in p-A collisions from induced radiation

    International Nuclear Information System (INIS)

    Arleo, F.; Kolevatov, R.; Peigne, S.; Sami, T.

    2016-01-01

    The current status of coherent energy loss is reviewed, both in theory and in its phenomenological applications to p-A collisions. The induced energy loss is not bounded in general, but only in the specific situation where the energetic parton is suddenly accelerated (as in deep inelastic scattering) in the nuclear medium. In the situation where the parton is asymptotic, i.e. 'prepared' at t = -∞ and 'tagged' at t = +∞ after crossing a nuclear medium of thickness L (a situation relevant to forward hadron production in p-A collisions), ΔE appears to be proportional to E. Both situations are detailed in the article

  5. Nuclear data needs in nuclear astrophysics: Charged-particle reactions

    International Nuclear Information System (INIS)

    Smith, Michael S.

    2001-01-01

    Progress in understanding a diverse range of astrophysical phenomena - such as the Big Bang, the Sun, the evolution of stars, and stellar explosions - can be significantly aided by improved compilation, evaluation, and dissemination of charged-particle nuclear reaction data. A summary of the charged-particle reaction data needs in these and other astrophysical scenarios is presented, along with recommended future nuclear data projects. (author)

  6. 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.

  7. Department of Nuclear Reactions - Overview

    International Nuclear Information System (INIS)

    Marianski, B.

    2010-01-01

    Full text: Our scientific activities in 2009 concentrated on four subjects: low energy nuclear physics, high energy nuclear physics, materials science and applications. · Low energy nuclear physics experiments were continued at the Heavy Ion Laboratory of Warsaw University in collaboration with foreign institutions: University of Jyvaskyla, Institute of Nuclear Research of the Ukrainian Academy of Science and Institut de Recherches Subatomique in Strasbourg. Dr Eryk Piasecki was nominated to full professor. · A group of our colleagues, involved in the Hermes collaboration which comprises 32 institutions from eleven countries at the Deutsches Elektronen Synchrotron ( DESY) in Hamburg, have continued the analysis of Spin Density Matrix Elements and asymmetry moments in ρ, φ, ω vector meson production. We hope that these studies will provide important constraints on the Generalized Parton Distribution (GPD). Prof. B. Zwieglinski and his team are involved in the large-scale international collaboration PANDA (antiProton ANnihilation at DArmstadt). They worked on the project of an electromagnetic calorimeter for the Panda detector at FAIR. Dr Dmytro Melychuk. a member of this team. defended his PhD thesis '' Development of electromagnetic calorimeter detectors and simulations for spectroscopic measurements of charmonium with PANDA ''. Grzegorz Kapica, a student in this team defended his master's thesis '' lnvestigating the energetic and time response of PWO scintillator with cooled photodiode readout in the gamma energy range 4 - 20 MeV '' · Materials science studies focused on semiconductor compounds that could be used in electronic and optoelectronic devices. This was done in close collaboration with the Institute of Electronic Materials Technology. In particular, a determination of the thermal stability of ohmic contacts in SiC monocrystals was performed. Beams from our Van de Graaff accelerator LECH were used in particle - induced X-ray emission (PIXE) studies

  8. Department of Nuclear Reactions - Overview

    Energy Technology Data Exchange (ETDEWEB)

    Marianski, B [The Andrzej Soltan Institute for Nuclear Studies, Swierk-Otwock (Poland)

    2010-07-01

    Full text: Our scientific activities in 2009 concentrated on four subjects: low energy nuclear physics, high energy nuclear physics, materials science and applications. centre dot Low energy nuclear physics experiments were continued at the Heavy Ion Laboratory of Warsaw University in collaboration with foreign institutions: University of Jyvaskyla, Institute of Nuclear Research of the Ukrainian Academy of Science and Institut de Recherches Subatomique in Strasbourg. Dr Eryk Piasecki was nominated to full professor. centre dot A group of our colleagues, involved in the Hermes collaboration which comprises 32 institutions from eleven countries at the Deutsches Elektronen Synchrotron ( DESY) in Hamburg, have continued the analysis of Spin Density Matrix Elements and asymmetry moments in rho, phi, omega vector meson production. We hope that these studies will provide important constraints on the Generalized Parton Distribution (GPD). Prof. B. Zwieglinski and his team are involved in the large-scale international collaboration PANDA (antiProton ANnihilation at DArmstadt). They worked on the project of an electromagnetic calorimeter for the Panda detector at FAIR. Dr Dmytro Melychuk, a member of this team, defended his PhD thesis ' Development of electromagnetic calorimeter detectors and simulations for spectroscopic measurements of charmonium with PANDA '. Grzegorz Kapica, a student in this team defended his master's thesis ' lnvestigating the energetic and time response of PWO scintillator with cooled photodiode readout in the gamma energy range 4 - 20 MeV ' centre dot Materials science studies focused on semiconductor compounds that could be used in electronic and optoelectronic devices. This was done in close collaboration with the Institute of Electronic Materials Technology. In particular, a determination of the thermal stability of ohmic contacts in SiC monocrystals was performed. Beams from our Van de Graaff accelerator LECH were used in particle - induced X

  9. Signatures of new phenomena in ultrarelativistic nuclear collisions

    International Nuclear Information System (INIS)

    Gyulassy, M.

    1983-11-01

    Three classes of observables are discussed which may shed light on the properties of the quark-gluon plasma formed in ultrarelativistic nuclear collisions. They are: (1) thermometers: the penetrating probes μ + μ - , γ, c, (2) barometers: transverse flow via , and (3) seismometers: fluctuations of dN/dy and dE perpendicular/dy. The need for reliable estimates of the background due to the non-equilibrium processes is emphasized. 49 references

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

    International Nuclear Information System (INIS)

    Zagrebaev, V.; Kozhin, A.

    1999-01-01

    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

  11. Nuclear reactions excited by recoil protons on a nuclear reactor

    International Nuclear Information System (INIS)

    Mukhammedov, S.; Khaydarov, A.; Barsukova, E.G.

    2006-01-01

    The nuclear reactions excited by recoil protons and of the detection possibility of the various chemical elements with the use of these secondary nucleus reactions were investigated. The recoil protons are produced on a nuclear reactor in the result of (n, p) inelastic and elastic scattering interaction of fast neutrons with nuclei of hydrogen. It is well known that the share of fast neutrons in energetic spectrum of reactor's neutrons in comparison with the share of thermal neutrons is small. . Consequently, the share of recoil protons produced in the result of fast neutron interaction with nuclei of light elements, capable to cause the nuclear reactions, is also small, des, due to Coulomb barrier of nuclei the recoil protons can cause the nuclear reactions only on nuclei of light and some middle elements. Our studies show that observable yields have radio nuclides excited in the result of nuclear reactions on Li, B, O, V and Cu. Our experimental results have demonstrated that the proton activation analysis based on the application of secondary nuclear reactions is useful technique to determine large contents of various light and medium chemical elements. Detection limits for studied chemical elements are estimated better than 10 ppm

  12. Department of Nuclear Reactions - Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2007-01-01

    The scientific activity of our department is traditionally focused on nuclear physics, atomic physics and material research. Our interest in nuclear physics is broad, ranging from the structure of a nucleon to the structure of the nucleus. The spin structure of a nucleon has been investigated within the HERMES Collaboration which comprises 32 institutions from 11 countries. The collaboration performs experiments at Deutches Elektronen-Synchrotron in Hamburg. Another large-scale international collaboration we are participating in is PANDA. The PANDA (antiProton ANnihilation at DArmstadt) experiment will be installed at the High Energy Storage Ring for antiprotons of the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. Our colleagues, led by Dr. B. Zwieglinski, have been working on the concept of a calorimeter, testing different scintillators. Many experiments in low energy nuclear physics were performed in collaboration with University of Jyvaeskylae, the Institute of Nuclear Research of the Ukrainian Academy of Science and Heavy Ion Laboratory of the Warsaw University. They were devoted to studying nucleus-nucleus interactions near the Coulomb barrier. This year, atomic studies focused on the L-shell ionisation of some heavy elements by silicon ions accelerated to the energy of 8.5-36 MeV. The results are presented in this report and are compared to different model calculations. Finally, I take great pleasure in congratulating Dr. L. Nowicki, whose study of uranium oxide structure, performed in collaboration with Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse in Orsay, was chosen as an important scientific achievement of our Institute in 2006. Apart from purely scientific activities, a few of our colleagues have been involved in education, giving lectures to students from high schools in Warsaw and Warsaw University. R. Ratajczak contributed to the 10 th Science Festival, an event organized for the general public every year

  13. 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.

  14. Mesonic atom production in high-energy nuclear collisions

    International Nuclear Information System (INIS)

    Wakai, M.; Bando, H.; Sano, M.

    1987-08-01

    The production probability of π-mesonic atom in high-energy nuclear collisions is estimated by a coalescence model. The production cross section is calculated for p + Ne and Ne + Ne systems at 2.1 GeV/A and 5.0 GeV/A beam energy. It is shown that nuclear fragments with larger charge numbers have the advantage in the formation of π-mesonic atoms. The cross section is proportional to Z 3 and of the order of magnitude of 1 ∼ 10 μb in all the above cases. The production cross sections of K-mesonic atoms are also estimated. (author)

  15. In honour of N. Yngve Öhrn: surveying proton cancer therapy reactions with Öhrn's electron nuclear dynamics method. Aqueous clusters radiolysis and DNA-base damage by proton collisions

    Science.gov (United States)

    Mclaurin, Patrick M.; Privett, Austin J.; Stopera, Christopher; Grimes, Thomas V.; Perera, Ajith; Morales, Jorge A.

    2015-02-01

    Proton cancer therapy (PCT) utilises high-energy H+ projectiles to cure cancer. PCT healing arises from its DNA damage in cancerous cells, which is mostly inflicted by the products from PCT water radiolysis reactions. While clinically established, a complete microscopic understanding of PCT remains elusive. To help in the microscopic elucidation of PCT, Professor Öhrn's simplest-level electron nuclear dynamics (SLEND) method is herein applied to H+ + (H2O)3-4 and H+ + DNA-bases at ELab = 1.0 keV. These are two types of computationally feasible prototypes to study water radiolysis reactions and H+-induced DNA damage, respectively. SLEND is a time-dependent, variational, non-adiabatic and direct-dynamics method that adopts a nuclear classical-mechanics description and an electronic single-determinantal wavefunction. Additionally, our SLEND + effective-core-potential method is herein employed to simulate some computationally demanding PCT reactions. Due to these attributes, SLEND proves appropriate for the simulation of various types of PCT reactions accurately and feasibly. H+ + (H2O)3-4 simulations reveal two main processes: H+ projectile scattering and the simultaneous formation of H and OH fragments; the latter process is quantified through total integrals cross sections. H+ + DNA-base simulations reveal atoms and groups displacements, ring openings and base-to-proton electron transfers as predominant damage processes. The authors warmly dedicate this SLEND investigation in honour of Professor N. Yngve Öhrn on the occasion of his 80th birthday celebration during the 54th Sanibel Symposium in St. Simons' Island, Georgia, on February 16-21, 2014. Associate Professor Jorge A. Morales was a former chemistry PhD student under the mentorship of Professor Öhrn and Dr Ajith Perera took various quantum chemistry courses taught by Professor Öhrn during his chemistry PhD studies. Both Jorge and Ajith look back to those great times of their scientific formation under

  16. Department of Nuclear Reactions - Overview

    International Nuclear Information System (INIS)

    Nowicki, L.

    2006-01-01

    In 2005 the Department held a steady course. Topics of nuclear physics, atomic physics and materials research that started in previous years were continued. Although our team was smaller than years ago, the scientific activity, estimated by number of published papers is still very high. Scientists of the Department are co-authors or authors of more than 50 papers. Nuclear physics, which is our main-stream activity, covered a wide energy range. It started close to the Coulomb barrier, where 6 He breakup on heavy nuclei were studied, and ended at zones of tens of GeV; such high energies were used to investigate spin structure of deuterons and to explore hadron leptoproduction. Traditionally, experimental investigations in the fields of atomic physics and of physics of materials completed the scene. Our old Van de Graaff accelerator Lech was used for studies of M-shell ionisation of heavy elements, for hardening of Ultra-High Molecular Weight Polyethylene and for characterisation of materials with RBS and NRA techniques. The VdG runs perfectly although it is over 40 years old. Two Ph.D. students finished their theses and were promoted. Izabela Fijal's work concerned multi-ionization and intrashell coupling effects for L-shell x-ray emission induced by heavy ions, while Sergiy Mezhevych showed studies on scattering of 11 B from carbon isotopes. It is obvious that contemporary works on physics do not arise in a single lab. Our contributions to many papers were possible due owing to collaborations involving many institutions. Some of them are listed: GSI, Darmstadt (PANDA Collaboration) DESY, Hamburg (HERMES Collaboration) Institut fuer Kernphysik, Forschungszentrum Juelich Forschungszentrum Rossendorf CSNSM, Orsay GANIL, Caen University of Huelva Institute of Nuclear Research, Kiev SLCJ, Warsaw ITME, Warsaw Some of our colleagues traditionally gave lectures and made physical demonstrations on Warsaw informal learning events: 9 th Science Picnic and 9 th Science Festival

  17. Study of the most violent collisions in Kr + Au and Pb + Au reactions close to 30 MeV per nucleon

    International Nuclear Information System (INIS)

    Galin, J.

    1991-01-01

    Within the past two years, the use of the high efficiency, sectorized 4π neutron detector, ORION, enabled a new approach in the investigation of nuclear collisions between very heavy nuclei. This talk discusses recent developments of this technique applied to Kr + Au and Pb + Au reactions induced at 32 and 29 MeV per nucleon respectively. The effectiveness of the neutron multiplicity meter as a filter on the violence of the collision is presented and the characteristics of the most violent collisions examined in some detail by considering associated charged particles

  18. The first nuclear chain reaction

    International Nuclear Information System (INIS)

    Zinn, W.H.

    1989-01-01

    The author offers his recollections of the experimental efforts beginning in 1939 which culminated in the Chain Reaction in the squash court on December 2, 1942. Recalled are Columbia University experiments which did much to establish the feasibility of the chain in natural uranium and which stimulated the creation of the Manhattan District. The Columbia group moved to the University of Chicago, where, in early summer of 1942, construction and analysis of a number of subcritical reactors (piles) gave assurance with a high probability that only a reasonable amount of uranium and moderator would be required

  19. Nuclear dynamics in heavy ion induced fusion-fission reactions

    International Nuclear Information System (INIS)

    Kapoor, S.S.

    1992-01-01

    Heavy ion induced fission and fission-like reactions evolve through a complex nuclear dynamics encountered in the medium energy nucleus-nucleus collisions. In the recent years, measurements of the fragment-neutron and fragment-charged particle angular correlations in heavy ion induced fusion-fission reactions, have provided new information on the dynamical times of nuclear deformations of the initial dinuclear complex to the fission saddle point and the scission point. From the studies of fragment angular distributions in heavy ion induced fission it has been possible to infer the relaxation times of the dinuclear complex in the K-degree of freedom and our recent measurements on the entrance channel dependence of fragment anisotropies have provided an experimental signature of the presence of fissions before K-equilibration. This paper reviews recent experimental and theoretical status of the above studies with particular regard to the questions relating to dynamical times, nuclear dissipation and the effect of nuclear dissipation on the K-distributions at the fission saddle in completely equilibrated compound nucleus. (author). 19 refs., 9 figs

  20. Department of Nuclear Reactions - Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2009-01-01

    Full text: Our activity in 2008 has focused on well-established domains of research: nuclear and atomic physics, and applications. · As far as nuclear physics is concerned; our interests are very broad, ranging from the structure of the nucleon to the structure of the nucleus including high-energy multifragmentation studies. Our colleagues led by Prof. Pawel Zupranski, members of the HERMES collaboration that comprises 32 institutions from eleven countries at the Deutsches Elektronen Synchrotron (DESY) in Hamburg, worked last year on the extraction of Spin Density Matrix Elements of vector mesons from scattering experiments on hydrogen targets. They also studied the distribution of quarks and gluons in nucleon. A team led by Prof. B. Zwieglinski was involved in the large-scale international collaboration PANDA (antiProton ANnihilation at DArmstadt). They studied the response of cooled PWO scintillators irradiated by gammas in the energy range of 4-20 MeV. The gammas were produced radiative proton capture on light by nuclei using a proton beam from the Van de Graaff accelerator of our Department. As a result, an important extrapolation of measurements performed by another group of physicists at much higher γ-ray energies was obtained. Low energy nuclear physics experiments were continued at the Heavy Ion Laboratory of Warsaw University in collaboration with foreign institutions: the University of Jyvaeskylae, the Institute of Nuclear Research of the Ukrainian Academy of Science and the Institute de Recherches Subatomique in Strasbourg. At high energies, a study of the isospin - dependence of the caloric curve was performed by the ALADIN Collaboration in a series of experiments at GSI - Darmstadt using radioactive beams of Sn and La. It was found that the asymmetry due to isospin is very weak. · Atomic physics studies were devoted to ionisation of heavy atoms by oxygen ions from the tandem accelerator of Erlangen-Nuernberg University. X-rays generated in the

  1. Department of Nuclear Reactions - Overview

    Energy Technology Data Exchange (ETDEWEB)

    Rusek, K [The Andrzej Soltan Institute for Nuclear Studies, Swierk-Otwock (Poland)

    2009-07-01

    Full text: Our activity in 2008 has focused on well-established domains of research: nuclear and atomic physics, and applications. {center_dot} As far as nuclear physics is concerned; our interests are very broad, ranging from the structure of the nucleon to the structure of the nucleus including high-energy multifragmentation studies. Our colleagues led by Prof. Pawel Zupranski, members of the HERMES collaboration that comprises 32 institutions from eleven countries at the Deutsches Elektronen Synchrotron (DESY) in Hamburg, worked last year on the extraction of Spin Density Matrix Elements of vector mesons from scattering experiments on hydrogen targets. They also studied the distribution of quarks and gluons in nucleon. A team led by Prof. B. Zwieglinski was involved in the large-scale international collaboration PANDA (antiProton ANnihilation at DArmstadt). They studied the response of cooled PWO scintillators irradiated by gammas in the energy range of 4-20 MeV. The gammas were produced radiative proton capture on light by nuclei using a proton beam from the Van de Graaff accelerator of our Department. As a result, an important extrapolation of measurements performed by another group of physicists at much higher {gamma}-ray energies was obtained. Low energy nuclear physics experiments were continued at the Heavy Ion Laboratory of Warsaw University in collaboration with foreign institutions: the University of Jyvaeskylae, the Institute of Nuclear Research of the Ukrainian Academy of Science and the Institute de Recherches Subatomique in Strasbourg. At high energies, a study of the isospin - dependence of the caloric curve was performed by the ALADIN Collaboration in a series of experiments at GSI - Darmstadt using radioactive beams of Sn and La. It was found that the asymmetry due to isospin is very weak. {center_dot} Atomic physics studies were devoted to ionisation of heavy atoms by oxygen ions from the tandem accelerator of Erlangen-Nuernberg University. X

  2. BNL325 - Nuclear reaction data display program

    International Nuclear Information System (INIS)

    Dunford, C.L.

    1994-01-01

    A computer code for the graphical display of nuclear reaction data is described. The code, which works on a computer with VMS operating system, can overlay experimental data from an EXFOR/CSISRS table-computation format with evaluated data from ENDF formatted data libraries. Originally, this code has been used at the U.S. National Nuclear Data Center to produce the well-known neutron cross-section atlas published as report BNL-325. (author). 3 tabs

  3. BNL325 - Nuclear reaction data display program

    Energy Technology Data Exchange (ETDEWEB)

    Dunford, C L

    1994-11-27

    A computer code for the graphical display of nuclear reaction data is described. The code, which works on a computer with VMS operating system, can overlay experimental data from an EXFOR/CSISRS table-computation format with evaluated data from ENDF formatted data libraries. Originally, this code has been used at the U.S. National Nuclear Data Center to produce the well-known neutron cross-section atlas published as report BNL-325. (author). 3 tabs.

  4. Enhancement Mechanisms of Low Energy Nuclear Reactions

    OpenAIRE

    Gareev, F. A.; Zhidkova, I. E.

    2005-01-01

    The review of possible stimulation mechanisms of LENR (low energy nuclear reaction) is represented. We have concluded that transmutation of nuclei at low energies and excess heat are possible in the framework of the modern physical theory - the universal resonance synchronization principle [1] and based on its different enhancement mechanisms of reaction rates are responsible for these processes [2]. The excitation and ionization of atoms may play role as a trigger for LENR. Superlow energy o...

  5. Nuclear quantum many-body dynamics: from collective vibrations to heavy-ion collisions

    International Nuclear Information System (INIS)

    Simenel, Cedric

    2012-01-01

    This report gives a summary of my research on nuclear dynamics during the past ten years. The choice of this field has been motivated by the desire to understand the physics of complex systems obeying quantum mechanics. In particular, the interplay between collective motion and single-particle degrees of freedom is a source of complex and fascinating behaviours. For instance, giant resonances are characterised by a collective vibration of many nucleons, but their decay may occur by the emission of a single nucleon. Another example could be taken from the collision of nuclei where the transfer of few nucleons may have a strong impact on the formation of a compound system is non trivial. To describe these complex systems, one needs to solve the quantum many-body problem. The description of the dynamics of composite systems can be very challenging, especially when two such systems interact. An important goal of nuclear physics is to find a unified way to describe the dynamics of nuclear systems. Ultimately, the same theoretical model should be able to describe vibrations, rotations, fission, all the possible outcomes of heavy-ion collisions (elastic and inelastic scattering, particle transfer, fusion, and multifragmentation), and even the dynamics of neutron star crust. This desire for a global approach to nuclear dynamics has strongly influenced my research activities. In particular, all the numerical applications presented in this report have been obtained from few numerical codes solving equations derived from the same variational principle. Beside the quest for a unified model of nuclear dynamics, possible applications of heavy-ion collisions such as the formation of new nuclei is also a strong motivation for the experimental and theoretical studies of reaction mechanisms. This report is not a review article, but should be considered as a reading guide of the main papers my collaborators and myself have published. It also gives the opportunity to detail some

  6. Electromagnetic radiation from nuclear collisions at RHIC energies

    CERN Document Server

    Turbide, Simon; Frodermann, Evan; Heinz, Ulrich

    2008-01-01

    The hot and dense strongly interacting matter created in collisions of heavy nuclei at RHIC energies is modeled with relativistic hydrodynamics, and the spectra of real and virtual photons produced at mid-rapidity in these events are calculated. Several different sources are considered, and their relative importance is compared. Specifically, we include jet fragmentation, jet-plasma interactions, the emission of radiation from the thermal medium and from primordial hard collisions. Our calculations consistently take into account jet energy loss, as evaluated in the AMY formalism. We obtain results for the spectra, the nuclear modification factor (R_AA), and the azimuthal anisotropy (v_2) that agree with the photon measurements performed by the PHENIX collaboration at RHIC.

  7. Disoriented Chiral Condensates in High-Energy Nuclear Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Randrup, Jorgen

    2000-10-18

    This brief lecture series discusses how our current understanding of chiral symmetry may be tested more globally in high-energy nuclear collisions by suitable extraction of pionic observables. After briefly recalling the general features of chiral symmetry, we focus on the SU(2) linear sigma model and show how a semi-classical mean-field treatment makes it possible to calculate its statistical properties, including the chiral phase diagram. Subsequently, we consider scenarios of relevance to high-energy collisions and discuss the features of the ensuing non-equilibrium dynamics and the associated characteristic signals. Finally, we illustrate how the presence of vacuum fluctuations or the inclusion of strangeness may affect the results quantitatively.

  8. Investigation of Rare Particle Production in High Energy Nuclear Collisions

    International Nuclear Information System (INIS)

    Crawford, Henry J.; Engelage, Jon M.

    1999-01-01

    Our program is an investigation of the hadronization process through measurement of rare particle production in high energy nuclear interactions. Such collisions of heavy nuclei provide an environment similar in energy density to the conditions in the Big Bang. We are currently involved in two major experiments to study this environment, E896 at the AGS and STAR at RHIC. We have completed our physics running of E896, a search for the H dibaryon and measurement of hyperon production in AuAu collisions, and are in the process of analyzing the data. We have produced the electronics and software for the STAR trigger and will begin to use these tools to search for anti-nuclei and strange hadrons when RHIC turns on later this year

  9. Breakup of spectator residues in relativistic nuclear collisions

    International Nuclear Information System (INIS)

    Warwick, A.I.; Wieman, H.H.; Gutbrod, H.H.

    1983-01-01

    Low energy nuclear fragments (12 4 He, and 20 Ne projectiles are measured to yield information on the breakup of the target nucleus. We discuss the shapes of the fragment energy spectra across this broad range of fragment mass and pick out the fission component by its binary breakup. Multiplicities of coincident fast charged particles are presented as a measure of the degree of violence of the initial stage of the collision. Angular distributions of light fragments (8< or =Z< or =11) give the average velocities imparted to the residue in central collisions, and these values are compared to the results of cascade calculations. Measurements of slow fragment multiplicities from central events reveal a many-fragment final state. In the light of this finding we develop a simple calculation of the Coulomb features of the observed spectra. The applicability of a statistical breakup model is discussed

  10. Theoretical studies in nuclear reaction and nuclear structure. Final report, January 1, 1975--June 30, 1976

    International Nuclear Information System (INIS)

    Banerjee, M.K.; Griffin, J.J.

    1977-07-01

    Progress in theoretical research is reported under the following readings: (1) few nuclear reactions, Eikonal approximations, and optical models; (2) pion reactions; (3) nuclear structure by reaction studies; (4) nuclear dynamics

  11. Microscopic description of low-energy nuclear collisions: review and perspective

    International Nuclear Information System (INIS)

    Bonche, Paul

    2000-01-01

    The primary goal of this lecture is a review of the microscopic approaches to nuclear reactions. Semi-phenomenological theories will not be discussed. First the Time-Dependent Hartree-Fock formalism is recalled. The effective nucleon-nucleon interactions used in TDHF calculations are discussed. Applications to collisions are presented in different approximation scheme, one-dimensional dynamics, approximate three-dimensional ones.... Finally two microscopic extensions beyond mean-field are reviewed: the variational principal of Balian and Veneroni and the implementation of residual two-body interactions in the Time-Dependent Density Matrix (TDDM) and the Extended Time-Dependent Hartree-Fock schemes (ET-DHF). (author)

  12. Direct interaction in nuclear reactions: a theory

    International Nuclear Information System (INIS)

    Dominicis, C.T. de

    1959-01-01

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

  13. Statistical theory of neutron-nuclear reactions

    International Nuclear Information System (INIS)

    Moldauer, P.A.

    1981-01-01

    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)

  14. Nuclear compression effects on pion production in nuclear collisions

    International Nuclear Information System (INIS)

    Sano, M.; Gyulassy, M.; Wakai, M.; Kitazoe, Y.

    1985-01-01

    We show that the method of analyzing the pion excitation function proposed by Stock et al. may determine only a part of the nuclear matter equation of state. With the addition of missing kinetic energy terms the implied high density nuclear equation of state would be much stiffer than expected from conventional theory. A stiff equation of state would also follow if shock dynamics with early chemical freeze out were valid. (orig.)

  15. Lin's theory of flux and nuclear reactions

    International Nuclear Information System (INIS)

    Ping-Wha Lin

    2002-01-01

    Mathematical development of Lin's theory of flux is presented. Based on the Theory, when a chemical reaction system is subjected to a high time rate of temperature change, it changes from equilibrium to non-equilibrium conditions. It is proved mathematically that, when a gas system is subjected to a high time rate of temperature increase, the activities of particles (molecules, atoms or nuclei, and electrons) are increased: the particles are accelerated; frequencies and amplitudes of electron and atomic vibrations in a molecule increased; average kinetic energy of the particles increased; atomic bonds are ruptured; electrons are caused to leave their orbits. If most or all of the electrons leave their orbits, the gas fluid becomes plasma, which is very active chemically. The acceleration of nuclei in the dynamic condition can lead to nuclear reactions. In the pilot plant studies conducted at Research Triangle, NC, USA, for SO 2 conversion to SO 3 by rapid heating, a 10-ft high vertically fired combustor (VFC) was used. Air containing 0.5% SO 2 is forced continuously through the VFC, where it is heated by burners for conversion of SO 2 to SO 3 . During the idle period of operation, no external heat is added to the system by turning off the burners. It is observed that, as the air passing through the VFC during the idle period of sixteen hours, the temperature of the flowing air consistently rises up rapidly from ambient temperature (90 deg F) at inlet of the VFC to an average temperature as high as 582 deg F (in the range of 840 deg F to 455 deg F) at one section of the VFC, an increase of about 500 deg F. The air flow temperature increase of such large magnitude and long duration clearly indicates that nuclear reactions are present in VFC. It is also found that the water vapour in the air stream has completely disappeared in the VFC, for no sulphuric acid formation resulting from the reaction of water and SO 3 is detected there. Presumably, the water vapour in the

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

    International Nuclear Information System (INIS)

    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 ≅ 182 region, structure of 182 Hg and 182 Au at high spin, a highly deformed band in 136 Pm and the anomalous h 11/2 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 209 Bi + 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 4π channel selection device, a novel x-ray detector, and a simple channel-selecting detector)

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

    International Nuclear Information System (INIS)

    Sarantites, D.G.

    1993-01-01

    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 82 Sr; structure of and identical bands in 182 Hg and 178 Pt; a highly deformed band in 136 Pm; particle decay of the 164 Yb compound nucleus; fusion reactions; proton evaporation; two-proton decay of 12 O; modeling and theoretical studies; excited 16 O disassembly into four alpha particles; 209 Bi + 136 Xe collisions at 28.2 MeV/amu; and development work on 4π solid angle gamma detectors, and x-ray detectors

  18. SkyNet: Modular nuclear reaction network library

    Science.gov (United States)

    Lippuner, Jonas; Roberts, Luke F.

    2017-10-01

    The general-purpose nuclear reaction network SkyNet evolves the abundances of nuclear species under the influence of nuclear reactions. SkyNet can be used to compute the nucleosynthesis evolution in all astrophysical scenarios where nucleosynthesis occurs. Any list of isotopes can be evolved and SkyNet supports various different types of nuclear reactions. SkyNet is modular, permitting new or existing physics, such as nuclear reactions or equations of state, to be easily added or modified.

  19. K X-rays and nuclear reaction times in the deep inelastic reactions U+U and U+Pb at 7.5 MeV/amu

    International Nuclear Information System (INIS)

    Stoller, C.

    1985-01-01

    The K-shell ionisation probability of the heavy reaction products emerging from binary deep inelastic collisions of U + U and U + Pb at 7.5 MeV/amu has been measured as a function of the total kinetic energy loss - Q. After subtraction of the ionisation probability due to internal conversion of γ-rays, a strongly Q-dependent Psub(K) is found, in agreement with theoretical predictions relating the change in ionisation probability to the nuclear sticking time. The deduced nuclear reaction times are in qualitative agreement with predictions from nuclear models of deep inelastic reactions. (orig.)

  20. Numerical magneto-hydrodynamics for relativistic nuclear collisions

    Energy Technology Data Exchange (ETDEWEB)

    Inghirami, Gabriele [Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); Goethe-Universitaet, Institute for Theoretical Physics, Frankfurt am Main (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Forschungszentrum Juelich, John von Neumann Institute for Computing, Juelich (Germany); Del Zanna, Luca [Universita di Firenze, Dipartimento di Fisica e Astronomia, Firenze (Italy); INAF - Osservatorio Astrofisico di Arcetri, Firenze (Italy); INFN - Sezione di Firenze, Firenze (Italy); Beraudo, Andrea [INFN - Sezione di Torino, Torino (Italy); Moghaddam, Mohsen Haddadi [INFN - Sezione di Torino, Torino (Italy); Hakim Sabzevari University, Department of Physics, P. O. Box 397, Sabzevar (Iran, Islamic Republic of); Becattini, Francesco [Universita di Firenze, Dipartimento di Fisica e Astronomia, Firenze (Italy); INFN - Sezione di Firenze, Firenze (Italy); Bleicher, Marcus [Frankfurt Institute for Advanced Studies, Frankfurt am Main (Germany); Goethe-Universitaet, Institute for Theoretical Physics, Frankfurt am Main (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Forschungszentrum Juelich, John von Neumann Institute for Computing, Juelich (Germany)

    2016-12-15

    We present an improved version of the ECHO-QGP numerical code, which self-consistently includes for the first time the effects of electromagnetic fields within the framework of relativistic magneto-hydrodynamics (RMHD). We discuss results of its application in relativistic heavy-ion collisions in the limit of infinite electrical conductivity of the plasma. After reviewing the relevant covariant 3 + 1 formalisms, we illustrate the implementation of the evolution equations in the code and show the results of several tests aimed at assessing the accuracy and robustness of the implementation. After providing some estimates of the magnetic fields arising in non-central high-energy nuclear collisions, we perform full RMHD simulations of the evolution of the quark-gluon plasma in the presence of electromagnetic fields and discuss the results. In our ideal RMHD setup we find that the magnetic field developing in non-central collisions does not significantly modify the elliptic flow of the final hadrons. However, since there are uncertainties in the description of the pre-equilibrium phase and also in the properties of the medium, a more extensive survey of the possible initial conditions as well as the inclusion of dissipative effects are indeed necessary to validate this preliminary result. (orig.)

  1. Nuclear reaction studies using inverse kinematics

    International Nuclear Information System (INIS)

    Shapira, D.

    1985-01-01

    Reaction studies with reversed kinematics refer to studies of nuclear reactions induced by a heavy projectile colliding with lighter target nuclei. The technique of using reversed kinematics is costly in terms of the available center-of-mass energy. Most of the projectile's energy goes into forward motion of the reaction products in the laboratory system. Examples are presented where the use of reversed kinematics techniques has provided new information on certain reaction processes. A list of kinematic properties and advantages they may afford is shown. Clearly the possible studies listed can be done without using reversed kinematics but because of the difficulty associated with some of these studies they were never performed until more energetic heavier beams have become available and the reversed kinematics technique was utilized

  2. New methods in nuclear reaction theory

    International Nuclear Information System (INIS)

    Redish, E.F.

    1979-01-01

    Standard nuclear reaction methods are limited to treating problems that generalize two-body scattering. These are problems with only one continuous (vector) degree of freedom (CDOF). The difficulty in extending these methods to cases with two or more CDOFs is not just the additional numerical complexity: the mathematical problem is usually not well-posed. It is hard to guarantee that the proper boundary conditions (BCs) are satisfied. Since this is not generally known, the discussion is begun by considering the physics of this problem in the context of coupled-channel calculations. In practice, the difficulties are usually swept under the rug by the use of a highly developed phenomenology (or worse, by the failure to test a calculation for convergence). This approach limits the kind of reactions that can be handled to ones occurring on the surface of where a second CDOF can be treated perturbatively. In the past twenty years, the work of Faddeev, the quantum three-body problem has been solved. Many techniques (and codes) are now available for solving problems with two CDOFs. A method for using these techniques in the nuclear N-body problem is presented. A set of well-posed (connected kernal) equations for physical scattering operators is taken. Then it is shown how approximation schemes can be developed for a wide range of reaction mechanisms. The resulting general framework for a reaction theory can be applied to a number of nuclear problems. One result is a rigorous treatment of multistep transfer reactions with the possibility of systematically generating corrections. The application of the method to resonance reactions and knock-out is discussed. 12 figures

  3. Aerosol simulation including chemical and nuclear reactions

    International Nuclear Information System (INIS)

    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

  4. Nuclear Forensics and Radiochemistry: Reaction Networks

    Energy Technology Data Exchange (ETDEWEB)

    Rundberg, Robert S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-22

    In the intense neutron flux of a nuclear explosion the production of isotopes may occur through successive neutron induced reactions. The pathway to these isotopes illustrates both the complexity of the problem and the need for high quality nuclear data. The growth and decay of radioactive isotopes can follow a similarly complex network. The Bateman equation will be described and modified to apply to the transmutation of isotopes in a high flux reactor. A alternative model of growth and decay, the GD code, that can be applied to fission products will also be described.

  5. Multiparticle production in particle and nuclear collisions, 2

    International Nuclear Information System (INIS)

    Kanki, Takeshi; Kinoshita, Kisei; Sumiyoshi, Hiroyuki; Takagi, Fujio.

    1990-01-01

    Multiparticle dynamics is related to many branches of particle and nuclear physics. This book provides a comprehensive review which covers the whole domain of multiparticle dynamics. The review consists of five chapters. Chapter D, which is the first chapter of this volume, is titled 'Mechanism of Fragmentation' and contains six sections dealing with 'parton densities inside hadrons', 'hadron fragmentation and quark picture', 'recombination type models', 'quark fragmentation models in soft interaction', 'diquark and its fragmentation' and 'fragmentation in string models'. Chapter E 'Diffractive Production of Hadrons' discusses 'diffractive inelastic processes of composite particles', 'diffractive processes and triple-pomeron coupling', 'properties of diffractive inelastic final states', and 'nature of pomeron'. Chapter F 'Unified Descriptions' focuses on 'general chain picture', 'dual parton model', 'Monte Carlo simulations' and 'unification of hard and soft interactions'. Chapter G, titled 'Multiparticle Production in Hadron-Nucleus Collisions and Other Nuclear Processes' and contains 11 sections. Chapter H presents conclusions. (N.K.)

  6. Need for reaction coordinates to ensure a complete basis set in an adiabatic representation of ion-atom collisions

    Science.gov (United States)

    Rabli, Djamal; McCarroll, Ronald

    2018-02-01

    This review surveys the different theoretical approaches, used to describe inelastic and rearrangement processes in collisions involving atoms and ions. For a range of energies from a few meV up to about 1 keV, the adiabatic representation is expected to be valid and under these conditions, inelastic and rearrangement processes take place via a network of avoided crossings of the potential energy curves of the collision system. In general, such avoided crossings are finite in number. The non-adiabatic coupling, due to the breakdown of the Born-Oppenheimer separation of the electronic and nuclear variables, depends on the ratio of the electron mass to the nuclear mass terms in the total Hamiltonian. By limiting terms in the total Hamiltonian correct to first order in the electron to nuclear mass ratio, a system of reaction coordinates is found which allows for a correct description of both inelastic channels. The connection between the use of reaction coordinates in the quantum description and the electron translation factors of the impact parameter approach is established. A major result is that only when reaction coordinates are used, is it possible to introduce the notion of a minimal basis set. Such a set must include all avoided crossings including both radial coupling and long range Coriolis coupling. But, only when reactive coordinates are used, can such a basis set be considered as complete. In particular when the centre of nuclear mass is used as centre of coordinates, rather than the correct reaction coordinates, it is shown that erroneous results are obtained. A few results to illustrate this important point are presented: one concerning a simple two-state Landau-Zener type avoided crossing, the other concerning a network of multiple crossings in a typical electron capture process involving a highly charged ion with a neutral atom.

  7. 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.

  8. Low energy nuclear reaction polyplasmon postulate

    Energy Technology Data Exchange (ETDEWEB)

    Russell, John L. [201 Heritage Drive, Apt. 208, Canton, GA 30093 (United States)], E-mail: RUSSELLJL@aol.com

    2008-11-15

    An explanation is proposed for the nuclear reactions that occur in the electrolysis class of LENR processes. The proposed explanation postulates that a proton, or deuteron, dissolved in the hydrogen bearing metal cathode, absorbs its associated atomic electron to become a short lived state of the neutron with the resulting neutrino in a singular wave function centered on the neutron. The energy required to initiate this endothermic reaction is supplied either by the ion current during electrolysis type experiments, or by ion bombardment in plasma type experiments. It is the energy of this bombardment of the cathode with heavy ions that creates a coherent polyplasmon field within crystalline metallic grains that are present in the metal cathode of typical active electrolysis cells. The LENR process consists of a second order reaction mediated by a coherent plasmon field excited in the conduction electrons in a hydrogen bearing metal that is in the form of crystalline grains of the order of a few microns in dimension. The coherent plasmon field in each grain is called a polyplasmon. The metallic grains typically form during solidification of a metal, the impurities being forced to the grain surfaces. The resulting grain thus forms a resonant structure that can be filled with a number of coherent plasmons, i.e., a polyplasmon. Energy from the polyplasmon is coupled to the nucleus via electron capture by hydrogen. Because the neutrino has mass, its wave function has a second class of solutions. This description can take the form of a short lived pairing with the neutron that results from electron capture by the hydrogen nucleus. This short-lived compound particle is named the 'dion' and in the case of deuterium results in a 'dineutron'. Because the dion and dineutron are formed with essentially thermal kinetic energy, they can capture in nearby nuclei, either in hydrogen or in the host metal. Most of the resulting exothermic nuclear energy is

  9. Low energy nuclear reaction polyplasmon postulate

    International Nuclear Information System (INIS)

    Russell, John L.

    2008-01-01

    An explanation is proposed for the nuclear reactions that occur in the electrolysis class of LENR processes. The proposed explanation postulates that a proton, or deuteron, dissolved in the hydrogen bearing metal cathode, absorbs its associated atomic electron to become a short lived state of the neutron with the resulting neutrino in a singular wave function centered on the neutron. The energy required to initiate this endothermic reaction is supplied either by the ion current during electrolysis type experiments, or by ion bombardment in plasma type experiments. It is the energy of this bombardment of the cathode with heavy ions that creates a coherent polyplasmon field within crystalline metallic grains that are present in the metal cathode of typical active electrolysis cells. The LENR process consists of a second order reaction mediated by a coherent plasmon field excited in the conduction electrons in a hydrogen bearing metal that is in the form of crystalline grains of the order of a few microns in dimension. The coherent plasmon field in each grain is called a polyplasmon. The metallic grains typically form during solidification of a metal, the impurities being forced to the grain surfaces. The resulting grain thus forms a resonant structure that can be filled with a number of coherent plasmons, i.e., a polyplasmon. Energy from the polyplasmon is coupled to the nucleus via electron capture by hydrogen. Because the neutrino has mass, its wave function has a second class of solutions. This description can take the form of a short lived pairing with the neutron that results from electron capture by the hydrogen nucleus. This short-lived compound particle is named the 'dion' and in the case of deuterium results in a 'dineutron'. Because the dion and dineutron are formed with essentially thermal kinetic energy, they can capture in nearby nuclei, either in hydrogen or in the host metal. Most of the resulting exothermic nuclear energy is absorbed in the plasmon

  10. Relativistic nucleus-nucleus collisions: Zone of reactions and space-time structure of fireball

    International Nuclear Information System (INIS)

    Anchishkin, D.; Muskeyev, A.; Yezhov, S.

    2010-01-01

    A zone of reactions is determined and then exploited as a tool in studying the space-time structure of an interacting system formed in a collision of relativistic nuclei. The time dependence of the reaction rates integrated over spatial coordinates is also considered. Evaluations are made with the help of the microscopic transport model UrQMD. The relation of the boundaries of different zones of reactions and the hypersurfaces of sharp chemical and kinetic freeze-outs is discussed.

  11. Constituent quark model for nuclear stopping in high energy nuclear collisions

    International Nuclear Information System (INIS)

    Choi, T.K.; Maruyama, M.; Takagi, F.

    1997-01-01

    We study nuclear stopping in high energy nuclear collisions using the constituent quark model. It is assumed that wounded nucleons with a different number of interacted quarks hadronize in different ways. The probabilities of having such wounded nucleons are evaluated for proton-proton, proton-nucleus, and nucleus-nucleus collisions. After examining our model in proton-proton and proton-nucleus collisions and fixing the hadronization functions, it is extended to nucleus-nucleus collisions. It is used to calculate the rapidity distribution and the rapidity shift of final-state protons in nucleus-nucleus collisions. The computed results are in good agreement with the experimental data on 32 S+ 32 S at E lab =200A GeV and 208 Pb+ 208 Pb at E lab =160A GeV. Theoretical predictions are also given for proton rapidity distribution in 197 Au+ 197 Au at √(s)=200A GeV (BNL-RHIC). We predict that the nearly baryon-free region will appear in the midrapidity region and the rapidity shift is left-angle Δy right-angle=2.24

  12. Light particle emission as a probe of reaction mechanism and nuclear excitation

    International Nuclear Information System (INIS)

    Guerreau, D.

    1989-01-01

    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

  13. Light ion reaction mechanisms and nuclear structure

    International Nuclear Information System (INIS)

    Robson, B.A.

    1986-01-01

    Of the many contributions to the subject 'Light ion reaction mechanism and nuclear structure', a few are selected and reviewed which highlight the present state of the field. Some contributions to the conference dealing with nuclear interactions are briefly outlined in the second section following an introductory section. Lane model calculations are compared with data for 9 Be and results are given showing angular distributions of the cross sections, the analyzing powers and the spin-rotation parameters for p - 40 Ca. Real central potential for d + 32 s resulting from the FB-analysis are compared with frozen density folding and delta-function folding. The third section deals with reaction mechanism. Data are cited which show near-side and far-side contributions to the calculated analyzing powers in the 116 Sn(d,p) 117 Sn (11.2 - ) transition. Calculations are compared with experimental A y and -(A yy + 2)/3. Also given are measurements of the cross sections and analyzing powers of the continuum energy spectra for the 58 Ni(p,p'x), along with relations between the analyzing powers and momentum transfer. The fourth section addresses nuclear structure. Cross sections and analyzing powers measured at 22 MeV for the reaction 208 Pb(p,t) 206 Pb(3 2 + ) are cited and considered. (Nogami, K.)

  14. Direct nuclear reaction experiments for stellar nucleosynthesis

    International Nuclear Information System (INIS)

    Cherubini, S.

    2016-01-01

    During the last two decades indirect methods where proposed and used in many experiments in order to measure nuclear cross sections between charged particles at stellar energies. These are among the lowest to be measured in nuclear physics. One of these methods, the Trojan Horse method, is based on the Quasi- Free reaction mechanism and has proved to be particularly flexible and reliable. It allowed for the measurement of the cross sections of various reactions of astrophysical interest using stable beams. The use and reliability of indirect methods become even more important when reactions induced by Radioactive Ion Beams are considered, given the much lower intensity generally available for these beams. The first Trojan Horse measurement of a process involving the use of a Radioactive Ion Beam dealt with the "1"8F(p,α)"1"5O process in Nova conditions. To obtain pieces of information on this process, in particular about its cross section at Nova energies, the Trojan Horse method was applied to the "1"8F(d,α "1"5O)n three body reaction. In order to establish the reliability of the Trojan Horse method approach, the Treiman-Yang criterion is an important test and it will be addressed briefly in this paper.

  15. [Electromagnetic studies of nuclear structure and reactions

    International Nuclear Information System (INIS)

    1992-01-01

    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 16 O(e,e'p), 12 C(e,e'pp) progress, large acceptance detector physics simulations), giant resonance studies (intermediate-energy experiments with solid-state detectors, the third response function in 12 C(e,e'p 0 ) and 16 O(e,e'p 0 ), comparison of the 12 C(e, e'p 0 ) and 16 O(e,e'p 3 ) reactions, quadrupole strength in the 16 O(e,e'α 0 ) reaction, quadrupole strength in the 12 C(e,e'α) reaction, analysis of the 12 C(e,e'p 1 ) and 16 O(e,e'p 3 ) angular distributions, analysis of the 40 Ca(e,e'x) reaction at low q, analysis of the higher-q 12 C(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)

  16. Japan Nuclear Reaction Data Centre (JCPRG), Progress Report

    International Nuclear Information System (INIS)

    Aikawa, M.

    2012-01-01

    In this report, we review the activities of Japan Nuclear Reaction Data Centre (JCPRG) since the last NRDC meeting in 2011. Our main objectives are as follows: a) Compilation of nuclear reaction data for two databases, NRDF and EXFOR b) Evaluation of astrophysical nuclear reaction data c) Development of software and systems d) Development of collaboration among Asian countries. (author)

  17. Abstract ID: 240 A probabilistic-based nuclear reaction model for Monte Carlo ion transport in particle therapy.

    Science.gov (United States)

    Maria Jose, Gonzalez Torres; Jürgen, Henniger

    2018-01-01

    In order to expand the Monte Carlo transport program AMOS to particle therapy applications, the ion module is being developed in the radiation physics group (ASP) at the TU Dresden. This module simulates the three main interactions of ions in matter for the therapy energy range: elastic scattering, inelastic collisions and nuclear reactions. The simulation of the elastic scattering is based on the Binary Collision Approximation and the inelastic collisions on the Bethe-Bloch theory. The nuclear reactions, which are the focus of the module, are implemented according to a probabilistic-based model developed in the group. The developed model uses probability density functions to sample the occurrence of a nuclear reaction given the initial energy of the projectile particle as well as the energy at which this reaction will take place. The particle is transported until the reaction energy is reached and then the nuclear reaction is simulated. This approach allows a fast evaluation of the nuclear reactions. The theory and application of the proposed model will be addressed in this presentation. The results of the simulation of a proton beam colliding with tissue will also be presented. Copyright © 2017.

  18. On the balance energy and nuclear dynamics in peripheral heavy-ion collisions

    International Nuclear Information System (INIS)

    Chugh, Rajiv; Puri, Rajeev K.

    2010-01-01

    We present here the system size dependence of balance energy for semi-central and peripheral collisions using quantum molecular dynamics model. For this study, the reactions of Ne 20 +Ne 20 , Ca 40 +Ca 40 , Ni 58 + Ni 58 , Nb 93 +Nb 93 , Xe 131 +Xe 131 , and Au 197 +Au 197 are simulated at different incident energies and impact parameters. A hard equation of state along with nucleon–nucleon cross-sections between 40 and 55 mb explains the data nicely. Interestingly, balance energy follows a power law ∝A τ for the mass dependence at all colliding geometries. The power factor τ is close to –1/3 in central collisions, whereas it is –2/3 for peripheral collisions suggesting stronger system size dependence at peripheral geometries. This also suggests that in the absence of momentum dependent interactions, Coulomb's interaction plays an exceedingly significant role. These results are further analyzed for nuclear dynamics at the balance point. (author)

  19. Study of electron pair production in hadron and nuclear collisions at the CERN SPS

    CERN Multimedia

    Liebold, H-P; Sako, H; Belaga, V; Bielcikova, J; Stachel, J

    2002-01-01

    The NA45/CERES experiment investigates primarily the production of electron-positron pairs and of direct photons in proton-nucleus and nucleus-nucleus collisions. For electron-positron pairs the experiment studies the continuum in the mass region of about 0.05 to 2 GeV/c$^2$ and the vector mesons $\\varrho ,~ \\omega$, and, $\\phi$. Since for electromagnetic probes final state interactions are practically negligible these observables are unique for studying the evolution and dynamics of ultrarelativistic heavy-ion collisions from the hot and dense early stage where a quark-gluon plasma is expected to be formed to the final freeze-out stage when hadrons decouple.\\\\ \\\\ The experiment also studies the spectral distributions of charged particles, their distribution relative to the reaction plane, and identified high momentum pions. Another topic of investigation are QED pairs produced in peripheral nuclear collisions.\\\\ \\\\ The first phase of the experiment, NA45, has been concluded with two main results: i) There is...

  20. Images of mycobacterium for nuclear reactions

    International Nuclear Information System (INIS)

    Lima, C.T.S.; Crispim, V.R.; Silva, M.G.

    2007-01-01

    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: 10 B (n,α) 7 Li and 10 B(α, p) 13 C. 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)

  1. Dispersion Theory of Direct Nuclear Reactions

    International Nuclear Information System (INIS)

    Shapiro, I.S.

    1963-01-01

    The main difficulty of nuclear theory is that nuclei contain many (i. e. more than two) but not too many particles. Therefore, the precise equations of motion (Schrodinger equation) become practically useless, and at the same time it is impossible to apply statistical methods with confidence. The latter circumstance is graphically expressed in direct nuclear reactions. The essence of these phenomena consists in that a particle hitting the target nucleus transfers its energy and momentum either to one nuclear nucleon or to a comparatively small group of nucleons. This fact would not by itself be surprising if at the same time we did not observe a directly opposite picture corresponding to the production of a compound nucleus, i. e. the statistical distribution among all degrees of freedom of the energy transferred to the nucleus. In macroscopic physics the co-existence of. such processes is impossible since they would contradict the second law of thermodynamics. Such processes occur quite often in nuclear physics because of the inapplic- ability of the asymptotic laws of the theory of probabilities. Since statistical methods were obviously unsuited for the direct process theory, this led to the conviction that it was necessary to return to the Schrodinger equation for a system of many interacting particles. But the technique of solving such equations is still confined to perturbation theory and therefore it was the latter that was used to describe direct nuclear reactions despite the fact that the interaction between nucleons is strong and the application of perturb- ation theory to the interaction of free nucleons (to n-p or p-p scattering, for example) leads to results which strongly contradict experimental data. The results of the application of perturbation theory to direct nuclear reactions sometimes agree with experimental data and sometimes cqntradict them, but in either case they can hardly satisfy the investigator because it seems impossible to give the

  2. Dispersion Theory of Direct Nuclear Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, I. S. [Institute Of Theoretical And Experimental Physics, Moscow, USSR (Russian Federation)

    1963-01-15

    The main difficulty of nuclear theory is that nuclei contain many (i. e. more than two) but not too many particles. Therefore, the precise equations of motion (Schrodinger equation) become practically useless, and at the same time it is impossible to apply statistical methods with confidence. The latter circumstance is graphically expressed in direct nuclear reactions. The essence of these phenomena consists in that a particle hitting the target nucleus transfers its energy and momentum either to one nuclear nucleon or to a comparatively small group of nucleons. This fact would not by itself be surprising if at the same time we did not observe a directly opposite picture corresponding to the production of a compound nucleus, i. e. the statistical distribution among all degrees of freedom of the energy transferred to the nucleus. In macroscopic physics the co-existence of. such processes is impossible since they would contradict the second law of thermodynamics. Such processes occur quite often in nuclear physics because of the inapplic- ability of the asymptotic laws of the theory of probabilities. Since statistical methods were obviously unsuited for the direct process theory, this led to the conviction that it was necessary to return to the Schrodinger equation for a system of many interacting particles. But the technique of solving such equations is still confined to perturbation theory and therefore it was the latter that was used to describe direct nuclear reactions despite the fact that the interaction between nucleons is strong and the application of perturb- ation theory to the interaction of free nucleons (to n-p or p-p scattering, for example) leads to results which strongly contradict experimental data. The results of the application of perturbation theory to direct nuclear reactions sometimes agree with experimental data and sometimes cqntradict them, but in either case they can hardly satisfy the investigator because it seems impossible to give the

  3. (Studies of target fragmentation in intermediate energy, relativistic and ultra-relativistic nuclear collisions)

    Energy Technology Data Exchange (ETDEWEB)

    Loveland, W.D.

    1991-08-01

    The work described herein is part of a project involving the study of low energy (< 10 MeV/A), intermediate energy (10--100 MeV/A) and relativistic (> 250 MeV/A) heavy ion reactions. In the low energy regime, we published a monograph on the properties of the heaviest elements and used that publication as a basis for making a set of best'' semi-empirical predictions of heavy element decay properties. The intermediate energy research effort focussed upon the completion of studies already begun and the initiation of a number of new experiments. In our study of a interaction of 21 MeV/nucleon {sup 129}Xe with {sup 197}Au, we compared the characteristics of the observed deep inelastic phenomena with various models of dissipative reactions and found significant discrepancies between observations and predictions. These discrepancies seemed to be caused by an improper treatment of pre-equilibrium in the early stages of the collision. In our study of the relativistic interaction of 400 MeV/nucleon {sup 12}C with {sup 197}Au, we reported the first direct physical measurement of the properties of the spallation residues from a nucleus-nucleus collision. We found the residue energies to be much lower than those predicted by the intranuclear cascade model, indicating some substantial modifications of that model are needed. But, we also found, indications of significant, non-zero values of the residue transverse momentum, a finding that calls into question the interpretation of a number of radiochemical recoil studies of the kinematics of high energy reactions. A program of performing numerical simulations of intermediate and high energy nuclear collisions using the QMD model was initiated.

  4. [Studies of target fragmentation in intermediate energy, relativistic and ultra-relativistic nuclear collisions

    International Nuclear Information System (INIS)

    Loveland, W.D.

    1991-08-01

    The work described herein is part of a project involving the study of low energy ( 250 MeV/A) heavy ion reactions. In the low energy regime, we published a monograph on the properties of the heaviest elements and used that publication as a basis for making a set of ''best'' semi-empirical predictions of heavy element decay properties. The intermediate energy research effort focussed upon the completion of studies already begun and the initiation of a number of new experiments. In our study of a interaction of 21 MeV/nucleon 129 Xe with 197 Au, we compared the characteristics of the observed deep inelastic phenomena with various models of dissipative reactions and found significant discrepancies between observations and predictions. These discrepancies seemed to be caused by an improper treatment of pre-equilibrium in the early stages of the collision. In our study of the relativistic interaction of 400 MeV/nucleon 12 C with 197 Au, we reported the first direct physical measurement of the properties of the spallation residues from a nucleus-nucleus collision. We found the residue energies to be much lower than those predicted by the intranuclear cascade model, indicating some substantial modifications of that model are needed. But, we also found, indications of significant, non-zero values of the residue transverse momentum, a finding that calls into question the interpretation of a number of radiochemical recoil studies of the kinematics of high energy reactions. A program of performing numerical simulations of intermediate and high energy nuclear collisions using the QMD model was initiated

  5. 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.

  6. Nuclear collision theory with many-body correlations, 2

    International Nuclear Information System (INIS)

    Kurihara, Yukio.

    1984-12-01

    A nuclear collision theory, in which the many-body correlation induced by the strong short-ranged repulsion and medium-ranged attraction of the realistic NN interaction is explicitly included, is applied to the deuteron+deuteron elastic scattering at low energies. Pair correlation functions calculated by the present theory are very different from the Hackenbroich et al. 's one. They contain not only the short-ranged suppressive correlation, but also the medium-ranged enhancing correlation. The former changes the shape of the d-d potential from the wine-bottle one. And the latter makes the d-d potential much more attractive. This effect is necessary for reproducing a bump around thatesub(cm)=90 0 in the experimental elastic differential cross section. The phase shifts evaluated by the present theory are compared with those from the resonating-group method. (author)

  7. Spectroscopy and reaction dynamics of collision complexes containing hydroxyl radicals

    Energy Technology Data Exchange (ETDEWEB)

    Lester, M.I. [Univ. of Pennsylvania, Philadelphia (United States)

    1993-12-01

    The DOE supported work in this laboratory has focused on the spectroscopic characterization of the interaction potential between an argon atom and a hydroxyl radical in the ground X{sup 2}II and excited A {sup 2}{summation}{sup +} electronic states. The OH-Ar system has proven to be a test case for examining the interaction potential in an open-shell system since it is amenable to experimental investigation and theoretically tractable from first principles. Experimental identification of the bound states supported by the Ar + OH (X {sup 2}II) and Ar + OH(A {sup 2}{summation}{sup +}) potentials makes it feasible to derive realistic potential energy surfaces for these systems. The experimentally derived intermolecular potentials provide a rigorous test of ab initio theory and a basis for understanding the dramatically different collision dynamics taking place on the ground and excited electronic state surfaces.

  8. Effective interaction: From nuclear reactions to neutron stars

    Indian Academy of Sciences (India)

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

  9. Single-collision studies of hot atom energy transfer and chemical reaction

    International Nuclear Information System (INIS)

    Valentini, J.J.

    1991-01-01

    This report discusses research in the collision dynamics of translationally hot atoms, with funding with DOE for the project ''Single-Collision Studies of Hot Atom Energy Transfer and Chemical Reaction,'' Grant Number DE-FG03-85ER13453. The work reported here was done during the period September 9, 1988 through October 31, 1991. During this period this DOE-funded work has been focused on several different efforts: (1) experimental studies of the state-to-state dynamics of the H + RH → H 2 R reactions where RH is CH 4 , C 2 H 6 , or C 3 H 8 , (2) theoretical (quasiclassical trajectory) studies of hot hydrogen atom collision dynamics, (3) the development of photochemical sources of translationally hot molecular free radicals and characterization of the high resolution CARS spectroscopy of molecular free radicals, (4) the implementation of stimulated Raman excitation (SRE) techniques for the preparation of vibrationally state-selected molecular reactants

  10. Kinematical program package for nuclear reaction

    International Nuclear Information System (INIS)

    Dai Nengxiong; Xie Ying

    1988-01-01

    A FORTRAN package is designed to provide users as many conveniences as possible. Besides adopting man-machine interaction mode and setting nuclide mass file, there are still some other features which are, for examples, the functions of offering the initial values for some transcendental equations and evaluating all the kinematic variables in nuclear reactions at low energies of the form of T (p,1)2, T (p,12)3 and T (p,12)34. All these make the users much easier to use the package

  11. Transport description of damped nuclear reactions

    International Nuclear Information System (INIS)

    Randrup, J.

    1983-04-01

    Part I is an elementary introduction to the general transport theory of nuclear dynamics. It can be read without any special knowledge of the field, although basic quantum mechanics is required for the formal derivation of the general expression for the transport coefficients. The results can also be used in a wider context than the present one. Part II gives the student an up-to-date orientation about recent progress in the understanding of the angular-momentum variables in damped reactions. The emphasis is here on the qualitative understanding of the physics rather than the, at times somewhat tedious, formal derivations

  12. Are the toroidal shapes of heavy-ion reactions seen in macroscopic drop collisions?

    International Nuclear Information System (INIS)

    Menchaca R, A.; Borunda, M.; Hidalgo, S.S.; Huidobro, F.; Michaelian, K.; Perez, A.; Rodriguez, V.

    1996-01-01

    Experiments involving the collisions of water, and mineral oil, drops are reported. The aim is to search for toroidal configurations predicted by, both, macroscopic fluid dynamic and nuclear models. Instead, we find the formation of thin liquid sheets surrounded by a somewhat thicker rim presenting a fingering instability. (Author)

  13. Nuclear spectroscopy using the neutron capture reaction

    International Nuclear Information System (INIS)

    Egidy, T.

    1982-01-01

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

  14. Transport description of damped nuclear reactions

    International Nuclear Information System (INIS)

    Randrup, J.

    1984-01-01

    This lecture series is concerned with the transport description of damped nuclear reactions. Part 1 is an elementary introduction to the general transport theory of nuclear dynamics. It can be read without any special knowledge of the field, although basic quantum mechanics is required for the formal derivation of the general expressions for the transport coefficients. The results can also be used in a wider context than the present one. Part 2 gives the student an up-to-date orientation about recent progress in the understanding of the angular-momentum variables in damped reactions. The emphasis is here on the qualitative understanding of the physics rather than the, at times somewhat tedious, formal derivations. More detailed presentations are due to be published soon. By necessity entire topics have been omitted. For example, no discussion is given of the calculation of the form factors, and the several instructive applications of the theory to transport of mass and change are not covered at all. For these topics they refer to the literature. It is hoped that the present notes provide a sufficient basis to make the literature on the subject accessible to the student

  15. A detailed test of the statistical theory of nuclear reactions

    NARCIS (Netherlands)

    Spijkervet, Andreas Lambertus

    1978-01-01

    Low-energy nuclear reactions are governed by two principal kinds of mechanisms: direct reaction mechanisms characterized by reaction times of the order of the transit time of the bombarding particle through the nucleus , and compound nucelar reaction mechanisms. The reaction times ot the latter are

  16. Methodology of hot nucleus calorimetry and thermometry produced by nuclear reactions around Fermi energies; Methodologie de la calorimetrie et de la thermometrie des noyaux chauds formes lors de collisions nucleaires aux energies de Fermi

    Energy Technology Data Exchange (ETDEWEB)

    Vient, E

    2006-12-15

    This work deals with the calorimetry and thermometry of hot nuclei produced in collisions Xe + Sn between 25 and 100 MeV/u. The apparatus for hot nucleus physical characterization is the 4{pi} detector array Indra. This study was made by using the event generators Gemini, Simon and Hipse and a data-processing filter simulating the complete operation of the multi-detector. The first chapter presents the different ways of producing hot nuclei. In the second and third chapters, the author presents a critical methodological study of calorimetry and thermometry applied to hot nuclei, different methods are reviewed, their accuracy and application range are assessed. All the calorimetry methods rely on the assumption that we are able to discriminate decay products of the hot nucleus from evaporated particles. In the fourth chapter, the author gives some ways of improving calorimetry characterization of the hot nucleus. An alternative method of calorimetry is proposed in the fifth chapter, this method is based on the experimental determination of an evaporation probability that is deduced from the physical characteristics of the particles present in a restricted domain of the space of velocities.

  17. Extension of PENELOPE to protons: Simulation of nuclear reactions and benchmark with Geant4

    International Nuclear Information System (INIS)

    Sterpin, E.; Sorriaux, J.; Vynckier, S.

    2013-01-01

    Purpose: Describing the implementation of nuclear reactions in the extension of the Monte Carlo code (MC) PENELOPE to protons (PENH) and benchmarking with Geant4.Methods: PENH is based on mixed-simulation mechanics for both elastic and inelastic electromagnetic collisions (EM). The adopted differential cross sections for EM elastic collisions are calculated using the eikonal approximation with the Dirac–Hartree–Fock–Slater atomic potential. Cross sections for EM inelastic collisions are computed within the relativistic Born approximation, using the Sternheimer–Liljequist model of the generalized oscillator strength. Nuclear elastic and inelastic collisions were simulated using explicitly the scattering analysis interactive dialin database for 1 H and ICRU 63 data for 12 C, 14 N, 16 O, 31 P, and 40 Ca. Secondary protons, alphas, and deuterons were all simulated as protons, with the energy adapted to ensure consistent range. Prompt gamma emission can also be simulated upon user request. Simulations were performed in a water phantom with nuclear interactions switched off or on and integral depth–dose distributions were compared. Binary-cascade and precompound models were used for Geant4. Initial energies of 100 and 250 MeV were considered. For cases with no nuclear interactions simulated, additional simulations in a water phantom with tight resolution (1 mm in all directions) were performed with FLUKA. Finally, integral depth–dose distributions for a 250 MeV energy were computed with Geant4 and PENH in a homogeneous phantom with, first, ICRU striated muscle and, second, ICRU compact bone.Results: For simulations with EM collisions only, integral depth–dose distributions were within 1%/1 mm for doses higher than 10% of the Bragg-peak dose. For central-axis depth–dose and lateral profiles in a phantom with tight resolution, there are significant deviations between Geant4 and PENH (up to 60%/1 cm for depth–dose distributions). The agreement is much

  18. Extension of PENELOPE to protons: simulation of nuclear reactions and benchmark with Geant4.

    Science.gov (United States)

    Sterpin, E; Sorriaux, J; Vynckier, S

    2013-11-01

    Describing the implementation of nuclear reactions in the extension of the Monte Carlo code (MC) PENELOPE to protons (PENH) and benchmarking with Geant4. PENH is based on mixed-simulation mechanics for both elastic and inelastic electromagnetic collisions (EM). The adopted differential cross sections for EM elastic collisions are calculated using the eikonal approximation with the Dirac-Hartree-Fock-Slater atomic potential. Cross sections for EM inelastic collisions are computed within the relativistic Born approximation, using the Sternheimer-Liljequist model of the generalized oscillator strength. Nuclear elastic and inelastic collisions were simulated using explicitly the scattering analysis interactive dialin database for (1)H and ICRU 63 data for (12)C, (14)N, (16)O, (31)P, and (40)Ca. Secondary protons, alphas, and deuterons were all simulated as protons, with the energy adapted to ensure consistent range. Prompt gamma emission can also be simulated upon user request. Simulations were performed in a water phantom with nuclear interactions switched off or on and integral depth-dose distributions were compared. Binary-cascade and precompound models were used for Geant4. Initial energies of 100 and 250 MeV were considered. For cases with no nuclear interactions simulated, additional simulations in a water phantom with tight resolution (1 mm in all directions) were performed with FLUKA. Finally, integral depth-dose distributions for a 250 MeV energy were computed with Geant4 and PENH in a homogeneous phantom with, first, ICRU striated muscle and, second, ICRU compact bone. For simulations with EM collisions only, integral depth-dose distributions were within 1%/1 mm for doses higher than 10% of the Bragg-peak dose. For central-axis depth-dose and lateral profiles in a phantom with tight resolution, there are significant deviations between Geant4 and PENH (up to 60%/1 cm for depth-dose distributions). The agreement is much better with FLUKA, with deviations within

  19. Low energy nuclear reactions: 2007 update

    International Nuclear Information System (INIS)

    Krivit, S. B.

    2007-01-01

    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/cm 2 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

  20. Heavy-ion collisions and the nuclear equation of state

    International Nuclear Information System (INIS)

    Keane, D.

    1993-01-01

    The overall goal of this project is to study nucleus-nucleus collisions experimentally at intermediate and relativistic energies, with emphasis on measurement and interpretation of correlation effects that provide insight into the nuclear phase diagram and the nuclear equation of state. During the course of this reporting period, the PI returned to Kent from a 15-month leave at Lawrence Berkeley Lab, which had been devoted 100% to work on this research project. The EOS Time Projection Chamber at LBL's Bevalac accelerator has continued to be the major focus of research for all of the supported personnel; about a year ago, this detector successfully took data in production mode for the first time, and accumulated in excess of 1000 hours of beam time before the termination of the Bevalac in February 1993. Reduction and analysis of these data is currently our first priority. Effort has also been devoted to the STAR detector at the Relativistic Heavy Ion Collider, in the form of contributions to the Conceptual Design Report, work on HV control hardware and software for use with the STAR Time Projection Chamber, and tracking software development

  1. Exclusive study of nuclear collisions at the AGS

    International Nuclear Information System (INIS)

    Rai, G.

    1993-08-01

    We propose to carry out a systematic and exclusive measurement of the energy and mass dependence of particle production, correlations and collective effects in Au+Au collisions. We wish to determine the highest compression achievable in nuclear matter and to study its properties. We shall search for evidence for an exotic Equation of State, that is, new physics such as Resonance Matter, Exotica, and QGP. We are also interested in signatures of critical phenomena in dilute nuclear matter. We propose to measure the four-momentum of light mass particles (π ± , K s 0 , K ± , Λ, n,p,d, 3 He, 4 He, 6 He, and the isotopes of Li and Be), projectile fragments from Z = 6 to Z = 79, and anti-proton production. The majority of the data will be acquired, on an event by event basis, from a state-of-the-art Time Projection Chamber (EOSTPC) built and used at LBL by the EOC collaboration. The TPC provides continuous tracking, almost 4π acceptance and particle identification for the light mass particles

  2. Use of SSNTD for measuring nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Bakr, M H [Division of Baic Nucl. Sc., NRC, Atomic Energy Authority Cairo (Egypt)

    1997-12-31

    Solid state nuclear track detectors (SSNTD) technique in nuclear reactions is reviewed. Special attention is given to the study of Makrofol-E films using a proposed optimum etching solution. The etching rate was 10.5 Mm/ hour. The energy resolution was measured and estimated to be 600 and 400 KeV in the energy ranges 1-2 MeV and 2-3 MeV respectively. Based on these results, the sensitivity threshold for gamma-particles in Makrofol-E is shifted up to 1 MeV, otherwise, there will be no discrimination between the etch - pits of gamma- particles with energies ranging from 0 to 1 MeV. The full angular distribution of the gamma-groups were measured in one run by means of a SSNTD sheel surrounding the target. A scattering chamber designed for gamma-particle angular distribution measurements is described. An example of the influence of energy loss in degrading Al foils in eliminating the energy angle dependence is given. The numerous curves of the range -energy dependence of gamma - particles in Makrofol - E after passing Al foils of different thicknesses are scaled in one schematic normograph. The later simplifies the process of choosing the suitable Al foil thickness or of determining the range- energy relation. The angular distributions of five gamma- groups from the {sup 56} Co (P, gamma) {sup 56} Fe reaction in the proton energy 1.6 -2.4 MeV have been measured using the designed chamber. A Makrofol - E film of 200 Mm thickness was exposed to the reaction products for 5 hours. This time was enough to get the angular distribution for (d/d) in the range 5-72 Mm barn/ster.

  3. Nuclear halo and its related reactions

    International Nuclear Information System (INIS)

    Zhang Huanqiao

    2005-01-01

    In order to search proton halo, the reaction cross sections of 27,28 P, 29 S and the corresponding isotones on Si target were measured at intermediate energies. The measured reaction cross sections of the N=12 and 13 isotones show an abrupt increase at Z=15. The experimental results for the isotones with Z=14 as well as 28 P can be well described by the modified Glauber theory of the optical limit approach. The enhancement of the reaction cross sections for 28 P could be explained in the modified Glauber theory with an enlarged core. Theoretical analysis with the modified Glauber theory of the optical limit and few-body approaches underpredicted the experimental data of 27 P. Our theoretical analysis shows that an enlarged core together with proton halo is probably the mechanism responsible for the enhancement of the cross sections for the reaction of 27 P+ 28 Si. In addition, we find from the experimental results that 29 S may have a moderate proton halo structure. Except the nuclei near or at drop-lines, halo may appear in the excited states of stable nuclei. By means of the asymptotic normalization coefficients (ANC's) extracted from transfer reactions of 11 B(d, p) 12 B, 12 C(d, p) 13 C, and H( 6 He, n) 6 Li, we have verified that the second ( Jπ = 2 - ) and third (Jπ = 1 - ) excited states in 12 B and the first (Jπ =1/2 + ) excited state in 13 C are the neutron halo states, while the second excited state (3.56 MeV, Jπ = 0 + ) in 6 Li is a proton-neutron halo state. We have proposed a procedure to extract the probability for valence particle being out of the binding potential from the measured nuclear asymptotic normalization coefficients. With this procedure, available data regarding the nuclear halo candidates are systematically analyzed and a number of halo nuclei are confirmed. Based on these results we have got a much relaxed condition for nuclear halo occurrence. Furthermore, we have presented the scaling laws for the dimensionless quantity 2 >/R 2 of

  4. Characteristics of violent collisions in Ar-induced reactions at intermediaire energies

    International Nuclear Information System (INIS)

    Rivet, M.F.; Borderie, B.

    1984-01-01

    We report on two experiments performed with the Ganil facility using the 27 MeV/u Ar beam. The first one concerns an intermediate mass system, Ar + Ag. For the second one a heavier fissile system, Ar + U, was chosen. For Ar + Ag information about fusion requires the measurements of evaporation residues and fission. In the Ar + U reaction, most of the collisions lead to fission. The violence of the collision is therefore determined from the correlation angle of the coincidence fission fragments

  5. Nuclear Data and Reaction Rate Databases in Nuclear Astrophysics

    Science.gov (United States)

    Lippuner, Jonas

    2018-06-01

    Astrophysical simulations and models require a large variety of micro-physics data, such as equation of state tables, atomic opacities, properties of nuclei, and nuclear reaction rates. Some of the required data is experimentally accessible, but the extreme conditions present in many astrophysical scenarios cannot be reproduced in the laboratory and thus theoretical models are needed to supplement the empirical data. Collecting data from various sources and making them available as a database in a unified format is a formidable task. I will provide an overview of the data requirements in astrophysics with an emphasis on nuclear astrophysics. I will then discuss some of the existing databases, the science they enable, and their limitations. Finally, I will offer some thoughts on how to design a useful database.

  6. Laser studies of chemical reaction and collision processes

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, G. [Columbia Univ., New York, NY (United States)

    1993-12-01

    This work has concentrated on several interrelated projects in the area of laser photochemistry and photophysics which impinge on a variety of questions in combustion chemistry and general chemical kinetics. Infrared diode laser probes of the quenching of molecules with {open_quotes}chemically significant{close_quotes} amounts of energy in which the energy transferred to the quencher has, for the first time, been separated into its vibrational, rotational, and translational components. Probes of quantum state distributions and velocity profiles for atomic fragments produced in photodissociation reactions have been explored for iodine chloride.

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

    International Nuclear Information System (INIS)

    Sarantites, D.G.

    1990-01-01

    This report discusses research in the following areas: nuclear structure; fusion reactions near and below the barrier; incomplete fusion and fragmentation reactions; and instrumentation and analysis. (LSP)

  8. Thermal Bremsstrahlung probing nuclear multifragmentation in nucleus-nucleus collisions around the Fermi energy; Bremsstrahlung thermique comme sonde de la multifragmentation nucleaire dans les collisions noyau-noyau aux energies de Fermi

    Energy Technology Data Exchange (ETDEWEB)

    D' Enterria, D.G

    2000-05-15

    The thermodynamical properties of nuclear matter at moderate temperatures and densities, in the vicinity of the predicted nuclear liquid-gas phase transition, are studied using as experimental probe the hard-photons (E{sub {gamma}} > 30 MeV) emitted in nucleus-nucleus collisions. Photon and charged-particle production in four different heavy-ion reactions (Ar{sup 36} + Au{sup 197}, Ag{sup 107}, Ni{sup 58}, C{sup 12} at 60 A*MeV) is measured exclusively and inclusively coupling the TAPS photon spectrometer with two charged-particle and intermediate-mass-fragment detectors covering nearly 4{pi}. We confirm that Bremsstrahlung emission in first-chance (off-equilibrium) proton-neutron collisions (pn{gamma}) is the dominant origin of hard photons. We also firmly establish the existence of a thermal radiation component emitted in second-chance proton-neutron collisions. This thermal Bremsstrahlung emission takes place in semi-central and central nucleus-nucleus reactions involving heavy targets. We exploit this observation i) to demonstrate that thermal equilibrium is reached during the reaction, ii) to establish a new thermometer of nuclear matter based on Bremsstrahlung photons, iii) to derive the thermodynamical properties of the excited nuclear sources and, in particular, to establish a 'caloric curve' (temperature versus excitation energy), and iv) to assess the time-scales of the nuclear break-up process. (author)

  9. 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) .

  10. Continuous spectrum of electromagnetic radiation in the collision of nuclear particles

    International Nuclear Information System (INIS)

    Amusia, M.Y.; Solovyov, A.V.

    1988-01-01

    The bremsstrahlung arising at the scattering of various particles on a nucleus has been considered with the demonstration of an important participation of the nuclear polarization in the collision process

  11. Report on the 1984 LBL workshop on detectors for relativistic nuclear collisions

    International Nuclear Information System (INIS)

    Schroeder, L.S.

    1984-11-01

    Highlights of the Workshop on Detectors for Relativistic Nuclear Collisions, held March 26-30, 1984, at the Lawrence Berkeley Laboratory are reviewed. (Complete proceedings are available as report LBL-18225.)

  12. Multiple nucleon transfer in damped nuclear collisions. [Lectures, mass charge, and linear and angular momentum transport

    Energy Technology Data Exchange (ETDEWEB)

    Randrup, J.

    1979-07-01

    This lecture discusses a theory for the transport of mass, charge, linear, and angular momentum and energy in damped nuclear collisions, as induced by multiple transfer of individual nucleons. 11 references.

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

    Energy Technology Data Exchange (ETDEWEB)

    Pshenichnov, Igor, E-mail: pshenich@fias.uni-frankfurt.d [Frankfurt Institute for Advanced Studies, J.-W. Goethe University, 60438 Frankfurt am Main (Germany); Institute for Nuclear Research, Russian Academy of Science, 117312 Moscow (Russian Federation); Botvina, Alexander [Frankfurt Institute for Advanced Studies, J.-W. Goethe University, 60438 Frankfurt am Main (Germany); Institute for Nuclear Research, Russian Academy of Science, 117312 Moscow (Russian Federation); Mishustin, Igor [Frankfurt Institute for Advanced Studies, J.-W. Goethe University, 60438 Frankfurt am Main (Germany); Kurchatov Institute, Russian Research Center, 123182 Moscow (Russian Federation); Greiner, Walter [Frankfurt Institute for Advanced Studies, J.-W. Goethe University, 60438 Frankfurt am Main (Germany)

    2010-03-15

    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 100AMeV. 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.

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

    International Nuclear Information System (INIS)

    Pshenichnov, Igor; Botvina, Alexander; Mishustin, Igor; Greiner, Walter

    2010-01-01

    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 100AMeV. 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.

  15. Coloring Rate of Phenolphthalein by Reaction with Alkaline Solution Observed by Liquid-Droplet Collision.

    Science.gov (United States)

    Takano, Yuuka; Kikkawa, Shigenori; Suzuki, Tomoko; Kohno, Jun-ya

    2015-06-11

    Many important chemical reactions are induced by mixing two solutions. This paper presents a new way to measure rates of rapid chemical reactions induced by mixing two reactant solutions using a liquid-droplet collision. The coloring reaction of phenolphthalein (H2PP) by a reaction with NaOH is investigated kinetically. Liquid droplets of H2PP/ethanol and NaOH/H2O solutions are made to collide, which induces a reaction that transforms H2PP into a deprotonated form (PP(2-)). The concentration of PP(2-) is evaluated from the RGB values of pixels in the colored droplet images, and is measured as a function of the elapsed time from the collision. The obtained rate constant is (2.2 ± 0.7) × 10(3) M(-1) s(-1), which is the rate constant for the rate-determining step of the coloring reaction of H2PP. This method was shown to be applicable to determine rate constants of rapid chemical reactions between two solutions.

  16. Nuclear reactions of medium and heavy target nuclei with high-energy projectiles

    International Nuclear Information System (INIS)

    Kozma, P.; Damdinsuren, C.

    1988-01-01

    The cross sections of a number of target fragmentation products formed in nuclear reactions of 3.65 AGeV 12 C-ions and 3.65 GeV protons with 197 Au have been measured. The measurements have been done by direct counting of irradiated targets with Ge(Li) gamma-spectrometers. Comparison between these and other data has been used to test the hypotheses of factorization and limiting fragmentation. The total cross section for residue production in both reactions indicates that target residues are formed mainly in central collisions

  17. Forging the link between nuclear reactions and nuclear structure.

    Science.gov (United States)

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

    2014-04-25

    A comprehensive description of all single-particle properties associated with the nucleus Ca40 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 residual attractive contribution from higher-body interactions for Ca40 of about 0.64  MeV/A.

  18. Whole study of nuclear matter collective motion in central collisions of heavy ions of the FOPI detector

    International Nuclear Information System (INIS)

    Bendarag, A.

    1999-01-01

    In this work we study the collective phenomena in the central collisions of heavy ions for the Au + Au, Xe + CsI and Ni + Ni systems at incident energies from 150 to 400 MeV/nucleon with the data of the FOPI detector. In order to describe completely the flow of the nuclear matter, we fit the double differential momentum distributions with two-dimensional Gaussian. We study the characteristic parameters of the collective flow (flow range, aspect ratios, flow parameter) versus the charge and the mass of the fragments as well as the incident energy and the centrality of the collisions. The transverse energy is used for selecting the central collisions. The method of the Gaussian fits requires also to reconstruct the reaction plane of the event. Then we correct the parameters for the finite number of particles effects and account for the influence of the acceptance of the detector. We confirm the importance of the thermal motion for the light charge or mass fragments and, conversely, the predominance of the collective motion for the heavy fragments. A common flow angle for all the types of particles is highlighted for the first time, demonstrating the power of the method of the Gaussian fits; The evolution of the other parameters confirms the observations done with other methods of flow analysis. These results should contribute to put constraints on the collision models and to enlarge our knowledge of the properties of the nuclear matter. (author)

  19. Have shock waves been observed in nuclear collisions

    International Nuclear Information System (INIS)

    Gudima, K.K.; Toneev, V.D.

    Experimental data on shock wave phenomena in nuclear reactions are analyzed within the kinetic theory rather than that of the hydrodynamic approach. Beginning with a presentation of the model, which is a generalization of the cascade--evaporation model to the case of the interaction of two nuclei, it is then ascertained to what degree the developed approach is valid. Next on the basis of this model the results of experiments performed are examined to find the effects of a shock wave. The results of this analysis and the related set-up of new experiments are discussed also. 34 references

  20. Suppression of soft nuclear bremsstrahlung in proton-nucleus collisions

    International Nuclear Information System (INIS)

    Goethem, M.J. van; Bacelar, J.C.S.; Hoefman, M.; Huisman, H.; Kalantar-Nayestanaki, N.; Loehner, H.; Messchendorp, J.G.; Ostendorf, R.W.; Schadmand, S.; Siemssen, R.H.; Turrisi, R.; Volkerts, M.; Wilschut, H.W.; Aphecetche, L.; Delagrange, H.; D'Enterria, D.; Martinez, G.; Schutz, Y.; Diaz, J.; Holzmann, R.

    2002-01-01

    Photon energy spectra up to the kinematic limit have been measured in 190 MeV proton reactions with light and heavy nuclei to investigate the influence of the multiple-scattering process on the photon production. Relative to the predictions of models based on a quasifree production mechanism, a strong suppression of bremsstrahlung is observed in the low-energy region of the photon spectrum. We attribute this effect to the interference of photon amplitudes due to multiple scattering of nucleons in the nuclear medium

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

    International Nuclear Information System (INIS)

    Lindstam, S.

    1975-06-01

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

  2. Correlations and polarization in electronic and atomic collisions and (e,2e) reactions

    International Nuclear Information System (INIS)

    Teubner, P.J.O.; Weigold, E.

    1992-01-01

    This volume contains the invited papers presented at the Sixth International Symposium on Correlations and Polarization in Electronic and Atomic collisions and (e,2e) Reactions held at Flinders University, Adelaide, Australia from 18-21 July, 1991. This symposium was a satellite meeting to the XVII International Conference on the Physics of Electronic and Atomic Collisions (ICPEAC) held in Brisbane, Australia. It follows a tradition of satellite meetings on (e,2e) collisions and on correlation and polarization in electronic and atomic collisions held in association with previous ICPEACs. The subject matter of this symposium covered that of the previous meeting at Hoboken, USA (1989) on correlation and polarization phenomena as well as that of the previous meeting at the University of Maryland (1989) on (e,2e) collisions. In addition it extended the scope to include some discussion of (e,3e), (γ,eγ) and (γ,2γ) coincidence measurements. The discussion of the current rapid advances in coincidence experiments, correlations and polarization measurements and related theoretical developments brought together 100 scientist from many countries with broad interdisciplinary backgrounds. The symposium stressed the common threads weaving through all these areas of research. (Author)

  3. Nuclear reaction rates and the nova outburst

    International Nuclear Information System (INIS)

    Starrfield, S.G.; Iliadis, C.

    2000-01-01

    In this paper we examined the consequences of improving the nuclear reaction library on our simulations of TNRs on 1.25M, WD and 1.35M, WDS. We have found that the changes in the rates have affected the nucleosynthesis predictions of our calculations but not, to any great extent, the gross features. In addition, we have used a lower mass accretion rate than in our previous studies in order to accrete (and eject) more material. This has, as expected, caused the peak values of some important parameters to increase over our previous studies at the same WD mass. However, because some important reaction rates have declined in the new compilation this has not increased the abundances for nuclei above aluminum and, in fact, they have declined while the abundances of both 26 Al and 27 Al have increased at both WD masses. In contrast, the abundance of 22 Na has declined at both WD masses over the values predicted in our earlier work. This has important implications with respect to predictions of the observability of novae with INTEGRAL

  4. Multifragmentation and evaporation: two competing processes in intermediate energy nuclear collisions

    International Nuclear Information System (INIS)

    Campi, X.; Desbois, J.; Lipparini, E.

    1984-05-01

    We study the conditions at which mutiple break up of nuclei occurs during a collision. A minimal temperature of about 5MeV seems to be necessary to produce multifragmentation. The average number of fragments produced is correlated with the average number of primary nucleon-nucleon collisions. Based on these ideas a simple model of evaporation-multifragmentation reactions is developed, which accounts for most of the existing data for protons and heavy ions induced reactions

  5. Heavy-ion collisions and the nuclear equation of state

    International Nuclear Information System (INIS)

    Keane, D.

    1992-01-01

    The overall goal of this project is to study nucleus-nucleus collisions experimentally at intermediate and relativistic energies, with emphasis on measurement and interpretation of correlation effects that provide insight into the nuclear phase diagram and the nuclear equation of state. During the past year, the PI has been on leave at Lawrence Berkeley Lab and has worked on this research project full-time. A large fraction of the effort of the PI and graduate students has gone into preparing for experiments using the Time Projection Chamber at LBL's Bevalac accelerator; in March 1992, this device successfully took data in production mode for the first time, and the first physics analysis is now under way. The PI has carried out simulations that help to define the physics performance and engineering specifications of the recently-approved STAR detector for the Relativistic Heavy Ion Collider, and has identified a new capability of this device with the potential for being an important quark-gluon plasma signature. A Postdoctoral Fellow, jointly supported by this grant and Kent State University, has been recruited to augment these efforts. Since May 1991, 11 journal papers have been published or submitted for publication; 2 conference proceedings and 9 reports or abstracts have also been published during the past year. One paper in Phys. Rev. Left., one in Phys. Rev. C, and one conference proceedings are based on the thesis project of one of the PI's Ph.D. students who is expected to graduate later this year. Partly in response to the impending closure of the Bevalac, the PI's group has recently joined the NA49 experiment at CERN

  6. Transverse momentum in high-energy nuclear collisions: Collective expansion

    International Nuclear Information System (INIS)

    Wang, X.; Hwa, R.C.

    1987-01-01

    Hadron production in the central region in high-energy nuclear collisions is investigated. The hydrodynamical expansion of a locally thermalized system is studied for both the cases with and without phase transition. The case with phase transition is considered by using a sound-velocity function c/sub s/(T) parametrized to fit the energy density determined in a lattice gauge calculation. The effect of a transverse rarefaction wave is included in the calculation of the temperature profile of the expanding fluid. The transverse-momentum distribution of hadrons is calculated by collecting all the hadrons produced when the hadron gas is cooled down to a freeze-out temperature at different times in the expansion. Fluctuation in initial temperature and radius is allowed due to variation in impact parameter. On the basis of a study of the thermalization process in the parton model we impose a constraint on the initial temperature and the thermalization time, the simultaneous variation of both of which gives rise to a relationship between the average transverse momentum and rapidity density. We have found that there is no so-called ''plateau'' region in that relationship. The implication on the diagnostics of a quark-gluon plasma is discussed

  7. Hubble evolution of fireball in relativistic nuclear collisions

    International Nuclear Information System (INIS)

    Zgura, Sorin; Besliu, Calin; Jipa, Alexandru

    2004-01-01

    The final state of Au + Au collisions at √s = 130 A GeV and 200 A GeV at RHIC has been reconstructed within the framework of the Buda-Lund hydro model, by performing a simultaneous fit to preliminary BRAHMS, PHENIX, PHOBOS and STAR data on two-particle Bose-Einstein correlations and identified single particle spectra. The Hubble constant is determined for cosmology. From this reconstructed final state and the knowledge of the equation of state of hot and dense hadronic matter (e.g. from lattice QCD calculations) one can, in principle, reconstruct the initial state of the reaction by running the (relativistic) hydrodynamical equations backwards in time and determine if this initial state had been in the QGP phase or not. Here we report on such a reconstruction within the framework of the Buda-Lund hydro model. This model fits are compared to RHIC's experiment data on identified particle spectra, two-particle Bose-Einstein or HBT correlations. (authors)

  8. Mean free paths for high energy hadron collisions in nuclear matter

    International Nuclear Information System (INIS)

    Strugalski, Z.

    1983-01-01

    The mean free paths for various collisions of high energy pion in nuclear matter are determined experimentally using pion-xenon nucleus collision events at 3.5 GeV/c momentum. The relation between the mean free path lambdasub(i) for hadron-nucleon particle producing collisions in nuclear matter and corresponding cross section σsub(i) for particle producing collisions of this hadron with free nucleon is derived and discussed. This relation is lambdasub(i)=k/σsub(i), where lambdasub(i) is in nucleons per fm 2 and σ sub(i) - in fm 2 per nucleon, correspondingly, k=3.00+-0.26 is a coefficient accounting for the display of the nucleon inner structure in hadron-nucleus collisions

  9. Mass and angular distributions of the reaction products in heavy ion collisions

    Science.gov (United States)

    Nasirov, A. K.; Giardina, G.; Mandaglio, G.; Kayumov, B. M.; Tashkhodjaev, R. B.

    2018-05-01

    The optimal reactions and beam energies leading to synthesize superheavy elements is searched by studying mass and angular distributions of fission-like products in heavy-ion collisions since the evaporation residue cross section consists an ignorable small part of the fusion cross section. The intensity of the yield of fission-like products allows us to estimate the probability of the complete fusion of the interacting nuclei. The overlap of the mass and angular distributions of the fusion-fission and quasifission products causes difficulty at estimation of the correct value of the probability of the compound nucleus formation. A study of the mass and angular distributions of the reaction products is suitable key to understand the interaction mechanism of heavy ion collisions.

  10. Study of Particle Production and Nuclear Fragmentation in Relativistic Heavy-Ion Collisions in Nuclear Emulsions

    CERN Multimedia

    2002-01-01

    % EMU11 \\\\ \\\\ We propose to use nuclear emulsions for the study of nuclear collisions of $^{207}$Pb, $^{197}$Au, and any other heavy-ion beams when they are available. We have, in the past, used $^{32}$S at 200A~GeV and $^{16}$O at 200A and 60A~GeV from CERN (Experiment EMU08) and at present the analysis is going on with $^{28}$Si beam from BNL at 14.5A~GeV. It will be important to compare the previous and the present investigations with the new $^{207}$Pb beam at 60-160A~GeV. We want to measure in nuclear emulsion, on an event by event basis, shower particle multiplicity, pseudorapidity density and density fluctuations of charged particles, charge multiplicity and angular distributions of projectile fragments, production and interaction cross-sections of heavily ionizing particles emitted from the target fragmentation. Special emphasis will be placed on the analysis of events produced in the central collisions which are selected on the basis of low energy fragments emitted from the target excitation. It woul...

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

    Energy Technology Data Exchange (ETDEWEB)

    Hirdt, J.A. [Department of Mathematics and Computer Science, St. Joseph' s College, Patchogue, NY 11772 (United States); Brown, D.A., E-mail: dbrown@bnl.gov [National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973-5000 (United States)

    2016-01-15

    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.

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

    International Nuclear Information System (INIS)

    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.

  13. Probing the nuclear structure with heavy-ion reactions

    International Nuclear Information System (INIS)

    Broglia, R.A.

    1982-01-01

    Nuclei display distortions in both ordinary space and in gauge space. It is suggested that it is possible to learn about the spatial distribution of the Nilsson orbitals and about the change of the pairing gap with the rotational frequency through the analysis of one- and two-nucleon transfer reactions induced in heavy-ion collisions

  14. {gamma}-radiation of excited nuclear discrete levels in peripheral heavy ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Korotkikh, V.L.; Chikin, K.A. [Scobeltsyn Institute of Nuclear Physics, Moscow State University (Russian Federation)

    2002-06-01

    A new process of a nuclear excitation to discrete states in peripheral heavy ion collisions is studied. High-energy photons are emitted by the exited nuclei with energies up to a few tens of GeV at angles of a few hundred microradians with respect to the beam direction. We show that a two-stage process, where an electron-positron pair is produced by virtual photons emitted by nuclei and then the electron or positron excites the nucleus, has a large cross-section. It is equal to about 5 b for CaCa collisions. On the one hand, it produces a significant {gamma}-rays background in the nuclear fragmentation region but, on the other hand, it could be used for monitoring the nuclear beam intensity at the LHC. These secondary nuclear photons could be a good signal for triggering peripheral nuclear collisions. (orig.)

  15. γ-radiation of excited nuclear discrete levels in peripheral heavy ion collisions

    Science.gov (United States)

    Korotkikh, V. L.; Chikin, K. A.

    A new process of a nuclear excitation to discrete states in peripheral heavy ion collisions is studied. High-energy photons are emitted by the exited nuclei with energies up to a few tens of GeV at angles of a few hundred microradians with respect to the beam direction. We show that a two-stage process, where an electron-positron pair is produced by virtual photons emitted by nuclei and then the electron or positron excites the nucleus, has a large cross-section. It is equal to about 5 b for CaCa collisions. On the one hand, it produces a significant γ-rays background in the nuclear fragmentation region but, on the other hand, it could be used for monitoring the nuclear beam intensity at the LHC. These secondary nuclear photons could be a good signal for triggering peripheral nuclear collisions.

  16. γ-radiation of excited nuclear discrete levels in peripheral heavy ion collisions

    International Nuclear Information System (INIS)

    Korotkikh, V.L.; Chikin, K.A.

    2002-01-01

    A new process of a nuclear excitation to discrete states in peripheral heavy ion collisions is studied. High-energy photons are emitted by the exited nuclei with energies up to a few tens of GeV at angles of a few hundred microradians with respect to the beam direction. We show that a two-stage process, where an electron-positron pair is produced by virtual photons emitted by nuclei and then the electron or positron excites the nucleus, has a large cross-section. It is equal to about 5 b for CaCa collisions. On the one hand, it produces a significant γ-rays background in the nuclear fragmentation region but, on the other hand, it could be used for monitoring the nuclear beam intensity at the LHC. These secondary nuclear photons could be a good signal for triggering peripheral nuclear collisions. (orig.)

  17. Brake reactions of distracted drivers to pedestrian Forward Collision Warning systems.

    Science.gov (United States)

    Lubbe, Nils

    2017-06-01

    Forward Collision Warning (FCW) can be effective in directing driver attention towards a conflict and thereby aid in preventing or mitigating collisions. FCW systems aiming at pedestrian protection have been introduced onto the market, yet an assessment of their safety benefits depends on the accurate modeling of driver reactions when the system is activated. This study contributes by quantifying brake reaction time and brake behavior (deceleration levels and jerk) to compare the effectiveness of an audio-visual warning only, an added haptic brake pulse warning, and an added Head-Up Display in reducing the frequency of collisions with pedestrians. Further, this study provides a detailed data set suited for the design of assessment methods for car-to-pedestrian FCW systems. Brake response characteristics were measured for heavily distracted drivers who were subjected to a single FCW event in a high-fidelity driving simulator. The drivers maintained a self-regulated speed of 30km/h in an urban area, with gaze direction diverted from the forward roadway by a secondary task. Collision rates and brake reaction times differed significantly across FCW settings. Brake pulse warnings resulted in the lowest number of collisions and the shortest brake reaction times (mean 0.8s, SD 0.29s). Brake jerk and deceleration were independent of warning type. Ninety percent of drivers exceeded a maximum deceleration of 3.6m/s 2 and a jerk of 5.3m/s 3 . Brake pulse warning was the most effective FCW interface for preventing collisions. In addition, this study presents the data required for driver modeling for car-to-pedestrian FCW similar to Euro NCAP's 2015 car-to-car FCW assessment. Practical applications: Vehicle manufacturers should consider the introduction of brake pulse warnings to their FCW systems. Euro NCAP could introduce an assessment that quantifies the safety benefits of pedestrian FCW systems and thereby aid the proliferation of effective systems. Copyright © 2017

  18. Global flow of glasma in high energy nuclear collisions

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Guangyao; Fries, Rainer J., E-mail: rjfries@comp.tamu.edu

    2013-06-25

    We discuss the energy flow of the classical gluon fields created in collisions of heavy nuclei at collider energies. We show how the Yang–Mills analog of Faraday's Law and Gauss' Law predicts the initial gluon flux tubes to expand or bend. The resulting transverse and longitudinal structure of the Poynting vector field has a rich phenomenology. Besides the well-known radial and elliptic flow in transverse direction, classical quantum chromodynamics predicts a rapidity-odd transverse flow that tilts the fireball for non-central collisions, and it implies a characteristic flow pattern for collisions of non-symmetric systems A+B. The rapidity-odd transverse flow translates into a directed particle flow v{sub 1} which has been observed at RHIC and LHC. The global flow fields in heavy ion collisions could be a powerful check for the validity of classical Yang–Mills dynamics in high energy collisions.

  19. Proton capture reactions and nuclear structure

    International Nuclear Information System (INIS)

    Kikstra, S.W.

    1989-01-01

    Experimental studies are described of the structure of 40 Ca and 42 Sc with measurements at proton-capture of (p, gamma) reactions. Where possible, an attempt has been made to interpret the results of the measurements in termsof existing models. The 40 Ca and 42 Sc nuclides were excited by bombarding 39 K and 41 Ca targets, respectively with low energy protons (E p = 0.3-3.0 MeV), that were produced by the Utrecht 3MV van de Graaff accelerator. From the measured energy and intensity of the gamma-rays created in the subsequent decay of the cuclei, information was obtained on the existence and properties of their excited states. In addition properties of two T = 3/2 levels at high excitation energy of the 9 Be nucleus were investigated. These levels were excited by the resonant absorption of gamma-rays from the 11 B(p, gamma) 12 C reaction. The results of the measurements are interpreted by a comparison to the analoque β-decay of 9 Li and to shell model calculations. The total decay energy of the superallowed O + → O + transition between the ground states of 42 Sc and 42 Ca was determined by measurements in Utrecht of the proton separation energy S p of 42 Sc and in Oak Ridge of S n of 42 Sc and 42 Ca. The results were used for verification of the conserved vector current hypothesis, which implies that the ft values of all superallowed O + → O + β-decays are the same. An attempt was made to describe properties of odd-parity states of A = 37-41 nuclei with a variant of the Warburton, Becker, Millener and Brown (WBMB) interaction.Finally a new method for the assignment of nuclear spins by a simple statistical analysis of spectroscopic information is proposed. (author). 169 refs.; 22 figs.; 24 schemes; 29 tabs

  20. Photon correlation: a micrometer of the nuclear reaction

    International Nuclear Information System (INIS)

    Marques, F.M.

    1997-01-01

    The technique of intensity interferometry was largely applied to pairs of bosons produced in heavy ion collisions to study the properties of their source. Recently this technique was applied also to photons which can be considered 'natural' probes in interferometry. The analysis of the results of two experiments, namely Kr + Mi at 60 MeV/N and Ta + Au at 40 MeV/N carried out with the multidetector TAPS at GANIL has shown the complexity of the space-time characteristic of the photon source. The standard hypothesis describing the production of high energy protons (E γ > 25 MeV) as starting from p-n Bremsstrahlung exclusively in the initial superposition of the two nuclei was rejected. Actually the typical form of the correlation function in which the correlation width corresponds to the inverse of the source size, is not satisfied by any of the two systems. Only, by the taking into account in the BUU calculations the photons produced later bring near the calculations and the data. This late production could originate in the recompression of the di-nuclei system. In analogy with previous application of this technique to stellar interferometry we have studied the structure of the photon source by Monte-Carlo calculations of the correlation function. For the simple case of a binary source the correlation function is dependent on the two source distributions, relative intensity and the space-time separation of the two sources. The results of this calculations evidence the sensitivity of the photon interferometry to different reaction mechanisms by the magnitude and also the shape of the correlation function. The best agreement with the data is obtained when the two nuclear fragments emit simultaneously the photons at a moment subsequent to the reaction moment

  1. Nuclear Waste Vitrification Efficiency: Cold Cap Reactions

    International Nuclear Information System (INIS)

    Kruger, A.A.; Hrma, P.R.; Pokorny, R.

    2011-01-01

    The cost and schedule of nuclear waste treatment and immobilization are greatly affected by the rate of glass production. Various factors influence the performance of a waste-glass melter. One of the most significant, and also one of the least understood, is the process of batch melting. Studies are being conducted to gain fundamental understanding of the batch reactions, particularly those that influence the rate of melting, and models are being developed to link batch makeup and melter operation to the melting rate. Batch melting takes place within the cold cap, i.e., a batch layer floating on the surface of molten glass. The conversion of batch to glass consists of various chemical reactions, phase transitions, and diffusion-controlled processes. These include water evaporation (slurry feed contains as high as 60% water), gas evolution, the melting of salts, the formation of borate melt, reactions of borate melt with molten salts and with amorphous oxides (Fe 2 O 3 and Al 2 O 3 ), the formation of intermediate crystalline phases, the formation of a continuous glass-forming melt, the growth and collapse of primary foam, and the dissolution of residual solids. To this list we also need to add the formation of secondary foam that originates from molten glass but accumulates on the bottom of the cold cap. This study presents relevant data obtained for a high-level-waste melter feed and introduces a one-dimensional (1D) mathematical model of the cold cap as a step toward an advanced three-dimensional (3D) version for a complete model of the waste glass melter. The 1D model describes the batch-to-glass conversion within the cold cap as it progresses in a vertical direction. With constitutive equations and key parameters based on measured data, and simplified boundary conditions on the cold-cap interfaces with the glass melt and the plenum space of the melter, the model provides sensitivity analysis of the response of the cold cap to the batch makeup and melter

  2. Cluster formation in nuclear reactions from mean-field inhomogeneities

    Science.gov (United States)

    Napolitani, Paolo; Colonna, Maria; Mancini-Terracciano, Carlo

    2018-05-01

    Perturbing fluids of neutrons and protons (nuclear matter) may lead, as the most catastrophic effect, to the rearrangement of the fluid into clusters of nucleons. A similar process may occur in a single atomic nucleus undergoing a violent perturbation, like in heavy-ion collisions tracked in particle accelerators at around 30 to 50 MeV per nucleon: in this conditions, after the initial collision shock, the nucleus expands and then clusterises into several smaller nuclear fragments. Microscopically, when violent perturbation are applied to nuclear matter, a process of clusterisation arises from the combination of several fluctuation modes of large-amplitude where neutrons and protons may oscillate in phase or out of phase. The imposed perturbation leads to conditions of instability, the wavelengths which are the most amplified have sizes comparable to small atomic nuclei. We found that these conditions, explored in heavy-ion collisions, correspond to the splitting of a nucleus into fragments ranging from Oxygen to Neon in a time interval shorter than one zeptosecond (10 ‑ 21s). From the out-of-phase oscillations of neutrons and protons another property arises, the smaller fragments belonging to a more volatile phase get more neutron enriched: in the heavy-ion collision case this process, called distillation, reflects in the isotopic distributions of the fragments. The resulting dynamical description of heavy-ion collisions is an improvement with respect to more usual statistical approaches, based on the equilibrium assumption. It allows in fact to characterise also the very fast early stages of the collision process which are out of equilibrium. Such dynamical description is the core of the Boltzmann-Langevin One Body (BLOB) model, which in its latest development unifies in a common approach the description of fluctuations in nuclear matter, and a predictive description of the disintegration of nuclei into nuclear fragments. After a theoretical introduction, a few

  3. Effective-energy budget in multiparticle production in nuclear collisions

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Aditya Nath; Sahoo, Raghunath [Indian Institute of Technology Indore, Discipline of Physics, School of Basic Sciences, Indore (India); Sarkisyan, Edward K.G. [CERN, Department of Physics, Geneva 23 (Switzerland); The University of Texas at Arlington, Department of Physics, Arlington, TX (United States); Sakharov, Alexander S. [CERN, Department of Physics, Geneva 23 (Switzerland); Kyungpook National University, Department of Physics, Daegu (Korea, Republic of)

    2014-11-15

    The dependencies of charged particle pseudorapidity density and transverse energy pseudorapidity density at midrapidity on the collision energy and on the number of nucleon participants, or centrality, measured in nucleus-nucleus collisions are studied in the energy range spanning a few GeV to a few TeV per nucleon. The approach in which the multiparticle production is driven by the dissipating effective energy of participants is introduced. This approach is based on the earlier proposed consideration, combining the constituent quark picture together with Landau relativistic hydrodynamics shown to interrelate the measurements from different types of collisions. Within this picture, the dependence on the number of participants in heavy-ion collisions are found to be well described in terms of the effective energy defined as a centrality-dependent fraction of the collision energy. For both variables under study, the effective-energy approach reveals a similarity in the energy dependence obtained for the most central collisions and centrality data in the entire available energy range. Predictions are made for the investigated dependencies for the forthcoming higher-energy measurements in heavy-ion collisions at the LHC. (orig.)

  4. Effective-energy budget in multiparticle production in nuclear collisions

    International Nuclear Information System (INIS)

    Mishra, Aditya Nath; Sahoo, Raghunath; Sarkisyan, Edward K.G.; Sakharov, Alexander S.

    2014-01-01

    The dependencies of charged particle pseudorapidity density and transverse energy pseudorapidity density at midrapidity on the collision energy and on the number of nucleon participants, or centrality, measured in nucleus-nucleus collisions are studied in the energy range spanning a few GeV to a few TeV per nucleon. The approach in which the multiparticle production is driven by the dissipating effective energy of participants is introduced. This approach is based on the earlier proposed consideration, combining the constituent quark picture together with Landau relativistic hydrodynamics shown to interrelate the measurements from different types of collisions. Within this picture, the dependence on the number of participants in heavy-ion collisions are found to be well described in terms of the effective energy defined as a centrality-dependent fraction of the collision energy. For both variables under study, the effective-energy approach reveals a similarity in the energy dependence obtained for the most central collisions and centrality data in the entire available energy range. Predictions are made for the investigated dependencies for the forthcoming higher-energy measurements in heavy-ion collisions at the LHC. (orig.)

  5. Japan Nuclear Reaction Data Centre (JCPRG) Progress Report

    International Nuclear Information System (INIS)

    2011-01-01

    In this report, we give a brief review of the activities carried out by the ''Japan Nuclear Reaction Data Centre (JCPRG)'' since the last NRDC meeting in 2009. The main subjects of our activities are; (1) reaction data compilation, (2) evaluation of the astrophysical nuclear reaction data for light nuclei, and (3) cooperation of nuclear data activities in Asia. Our activities in detail are as follows. a) New reaction data compilation (NRDF and EXFOR) b) Conversion of old NRDF to EXFOR c) Bibliography compilation (CINDA) d) Evaluation of astrophysical nuclear reaction data based on theoretical calculations for light nuclei e) Collaboration among nuclear data physicists in Asia for the EXFOR compilation to form a stable base f) Database maintenance and services (NRDF, EXFOR/ENDF and CINDA) g) Development of software systems (GSYS) h) Customer services

  6. Overview of Light Hydrogen-Based Low Energy Nuclear Reactions

    Science.gov (United States)

    Miley, George H.; Shrestha, Prajakti J.

    This paper reviews light water and hydrogen-based low-energy nuclear reactions (LENRs) including the different methodologies used to study these reactions and the results obtained. Reports of excess heat production, transmutation reactions, and nuclear radiation emission are cited. An aim of this review is to present a summary of the present status of light water LENR research and provide some insight into where this research is heading.

  7. QUARKONIUM PRODUCTION IN RELATIVISTIC NUCLEAR COLLISIONS. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP, VOLUME 12

    Energy Technology Data Exchange (ETDEWEB)

    KHARZEEV,D.

    1999-04-20

    The RIKEN-BNL Workshop on Quarkonium Production in Relativistic Nuclear Collisions was held September 28--October 2, 1998, at Brookhaven National Laboratory. The Workshop brought together about 50 invited participants from around the world and a number of Brookhaven physicists from both particle and nuclear physics communities.

  8. Quarkonium production in relativistic nuclear collisions. Proceedings of Riken BNL Research Center Workshop,Volume 12

    International Nuclear Information System (INIS)

    Kharzeev, D.

    1999-01-01

    The RIKEN-BNL Workshop on Quarkonium Production in Relativistic Nuclear Collisions was held September 28--October 2, 1998, at Brookhaven National Laboratory. The Workshop brought together about 50 invited participants from around the world and a number of Brookhaven physicists from both particle and nuclear physics communities

  9. Investigation of nuclear matter properties by means of high energy nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Stock, R.

    1985-09-01

    We review recent advances towards an understanding of high density nuclear matter, as created in central collisions of nuclei at high energy. In particular, information obtained for the nuclear matter equation of state will be discussed. The lectures focus on the Bevalac energy domain of 0.4 to 2 GeV per projectile nucleon. (orig.)

  10. Collisions of polyatomic ions with surfaces: incident energy partitioning and chemical reactions

    International Nuclear Information System (INIS)

    Zabka, J.; Roithova, J.; Dolejsek, Z.; Herman, Z.

    2002-01-01

    Collision of polyatomic ions with surfaces were investigated in ion-surface scattering experiments to obtain more information on energy partitioning in ion-surface collision and on chemical reactions at surfaces. Mass spectra, translation energy and angular distributions of product ions were measured in dependence on the incident energy and the incident angle of polyatomic projectiles. From these data distributions of energy fractions resulting in internal excitation of the projectile, translation energy of the product ions, and energy absorbed by the surface were determined. The surface investigated were a standard stainless steel surface, covered by hydrocarbons, carbon surfaces at room and elevated temperatures, and several surfaces covered by a self-assembled monolayers (C 12 -hydrocarbon SAM, C 11 -perfluorohydrocarbon SAM, and C 11 hydrocarbon with terminal -COOH group SAM). The main processes observed at collision energies of 10 - 50 eV were: neutralization of the ions at surfaces, inelastic scattering and dissociations of the projectile ions, quasi elastic scattering of the projectile ions, and chemical reactions with the surface material (usually hydrogen-atom transfer reactions). The ion survival factor was estimated to be a few percent for even-electron ions (like protonated ethanol ion, C 2 H 5 O + , CD 5 + ) and about 10 - 10 2 times lower for radical ions (like ethanol and benzene molecular ions, CD 4 + ). In the polyatomic ion -surface energy transfer experiments, the ethanol molecular ion was used as a well-characterized projectile ion. The results with most of the surfaces studied showed in the collision energy range of 13 - 32 eV that most collisions were strongly inelastic with about 6 - 8 % of the incident projectile energy transformed into internal excitation of the projectile (independent of the incident angle) and led partially to its further dissociation in a unimolecular way after the interaction with the surface. The incident energy

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

    International Nuclear Information System (INIS)

    Griffin, J.J.

    1988-09-01

    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

  12. Two-dimensional multiplicity fluctuation analysis of target residues in nuclear collisions

    International Nuclear Information System (INIS)

    Dong-Hai, Zhang; Yao-Jie, Niu; Li-Chun, Wang; Wen-Jun, Yan; Li-Juan, Gao; Ming-Xing, Li; Li-Ping, Wu; Hui-Ling, Li; Jun-Sheng, Li

    2010-01-01

    Multiplicity fluctuation of the target residues emitted in the interactions in a wide range of projectile energies from 500 A MeV to 60 A GeV is investigated in the framework of two-dimensional scaled factorial moment methodology. The evidence of non-statistical multiplicity fluctuation is found in 16 O–AgBr collisions at 60 A GeV, but not in 56 Fe–AgBr collisions at 500 A MeV, 84 Kr–AgBr collisions at 1.7 A GeV, 16 O–AgBr collisions at 3.7 A GeV and 197 Au–AgBr collisions at 10.7 A GeV. (nuclear physics)

  13. Reaction mechanisms in coherent nuclear photoproduction

    International Nuclear Information System (INIS)

    Lazard, C.

    Nuclear coherent pion photoproduction is studied. Pion rescattering and propagation effects inside nucleus and mesic exchange current effects are discussed. Influence of nuclear wave functions and Fermi motion is presented [fr

  14. Microjets and coated wheels: versatile tools for exploring collisions and reactions at gas-liquid interfaces.

    Science.gov (United States)

    Faust, Jennifer A; Nathanson, Gilbert M

    2016-07-07

    This tutorial review describes experimental aspects of two techniques for investigating collisions and reactions at the surfaces of liquids in vacuum. These gas-liquid scattering experiments provide insights into the dynamics of interfacial processes while minimizing interference from vapor-phase collisions. We begin with a historical survey and then compare attributes of the microjet and coated-wheel techniques, developed by Manfred Faubel and John Fenn, respectively, for studies of high- and low-vapor pressure liquids in vacuum. Our objective is to highlight the strengths and shortcomings of each technique and summarize lessons we have learned in using them for scattering and evaporation experiments. We conclude by describing recent microjet studies of energy transfer between O2 and liquid hydrocarbons, HCl dissociation in salty water, and super-Maxwellian helium evaporation.

  15. Formation and disintegration of high-density nuclear matter in heavy-ion collisions

    International Nuclear Information System (INIS)

    Kitazoe, Yasuhiro; Matsuoka, Kazuo; Sano, Mitsuo

    1976-01-01

    The formation of high-density nuclear matter which may be expected to be attained in high-energy heavy-ion collisions and the subsequent disintegration of dense matter are investigated by means of the hydrodynamics. Head-on collisions of identical nuclei are considered in the nonrelativistic approximation. The compressed density cannot exceed 4 times of the normal one so long as the freedom of only nucleons is considered, and can become higher than 4 times when other freedoms such as the productions of mesons and also nucleon isobars are additionally taken into account. The angular distributions for ejected particles predominate both forwards and backwards at low collision energies, corresponding to the formation of nuclear density less than 2 times of the normal density and become isotropic at the point of 2 times of the normal one. As the collision energy increases further, lateral ejection is intensified gradually. (auth.)

  16. Angular pattern of minijet transverse energy flow in hadron and nuclear collisions

    International Nuclear Information System (INIS)

    Leonidov, A.V.; Ostrovsky, D.M.

    2002-01-01

    The azimuthal asymmetry of a minijet system produced at the early stage of nucleon-nucleon and nuclear collisions in a central rapidity window is studied. We show that, in pp collisions, the minijet-transverse-energy production in a central rapidity window is essentially unbalanced in azimuth because of asymmetric contributions in which only one minijet hits the acceptance window. We further study the angular pattern of the transverse-energy flow generated by semihard degrees of freedom at the early stage of high-energy nuclear collisions and its dependence on the number of semihard collisions in the models either including or neglecting soft contributions to the inelastic cross section at RHIC and LHC energies, as well as on the choice of infrared cutoff

  17. Angular pattern of minijet transverse energy flow in hadron and nuclear collisions

    International Nuclear Information System (INIS)

    Leonidov, A.V.; Ostrovsky, D.M.

    2000-01-01

    The azimuthal asymmetry of a minijet system produced at the early stage of nucleon-nucleon and nuclear collisions in a central rapidity window is studied. We show that in pp collisions the minijet transverse energy production in a central rapidity window is essentially unbalanced in the azimuth due to asymmetric contributions in which only one minijet hits the acceptance window. We further study the angular pattern of the transverse energy flow generated by the semihard degrees of freedom at the early stage of high energy nuclear collisions and its dependence on the number of semihard collisions in the models both including and neglecting soft contributions to the inelastic cross section at RHIC and LHC energies as well as on the choice of the infrared cutoff. (orig.)

  18. From nuclear reactions to neutron stars

    Indian Academy of Sciences (India)

    2014-04-30

    Apr 30, 2014 ... 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 ...

  19. Nuclear Astrophysics and Neutron Induced Reactions: Quasi-Free Reactions and RIBs

    International Nuclear Information System (INIS)

    Cherubini, S.; Spitaleri, C.; Crucilla, V.; Gulino, M.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Puglia, S.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Coc, A.; Kubono, S.; Binh, D. N.; Hayakawa, S.; Wakabayashi, Y.; Yamaguchi, H.; Burjan, V.; Kroha, V.; De Sereville, N.

    2010-01-01

    The use of quasi-free reactions in studying nuclear reactions between charged particles of astrophysical interest has received much attention over the last two decades. The Trojan Horse Method is based on this approach and it has been used to study a number of reactions relevant for Nuclear Astrophysics. Recently we applied this method to the study of nuclear reactions that involve radioactive species, namely to the study of the 18 F+p→ 15 O+α process at temperatures corresponding to the energies available in the classical novae scenario. Quasi-free reactions can also be exploited to study processes induced by neutrons. This technique is particularly interesting when applied to reaction induced by neutrons on unstable short-lived nuclei. Such processes are very important in the nucleosynthesis of elements in the sand r-processes scenarios and this technique can give hints for solving key questions in nuclear astrophysics where direct measurements are practically impossible.

  20. Drift-tube studies of ion-molecule reactions at low collision energies

    International Nuclear Information System (INIS)

    Chatterjee, B.K.

    1988-01-01

    This thesis presents experimental studies of ion-molecule reactions at low collision energies using two drift tube mass spectrometer apparatus. The reactions studied are (i) proton transfer from HeH + to ArH + , (ii) charge and ion transfer reactions of O 2 2+ with NO, CO 2 , Ne and O 2 + ( 4 π u ) with CO 2 , (iii) oxidation reactions of Zr + and ZrO + with NO, CO 2 and O 2 , (iv) vibrational quenching reactions of H 3 + with He, (v) termolecular clustering reactions of H 2 CN + and H 2 CN + (HCN) (with He as the third body), (vi) three body association reactions of H + and D + with He (with He as the third body) and (vii) termolecular association reaction of NO + with NO (with Ne as third body). All the reactions were studied at thermal energies (at room temperature), reactions of O 2 2+ with NO and CO 2 , Zr + with NO/CO 2 /O 2 were also studied at center-of-mass energies higher than thermal and the association reactions of H 2 CN + /H 2 CN + (HCN) with HCN and H + /D + with He were studied at low temperatures. In addition, the thesis presents model calculations for the sweep-out effect which is an instrumental effect. A super Langevin rate constant is introduced which is a higher-order correction to the Langevin model. A theoretical model for the three-body ion-atom association rate constant is presented in the appendix of the thesis

  1. Contribution to the understanding of ion-gas reactions in ICP-MS collision reaction cells: application to the resolution of isobaric and polyatomic interferences

    International Nuclear Information System (INIS)

    Quemet, A.

    2012-01-01

    Inductively Coupled Plasma Mass Spectrometry (ICP-MS) emerged as the most essential technique in inorganic analytical chemistry thanks to its numerous assets, particularly its flexibility, its sensitivity and its reproducibility. As part of the elementary and isotopic analysis of irradiated fuel and transmutation target, the analyst is faced with a complex mass spectrum, due to the presence of many radionuclides. ICP-MS can not differentiate ions with the same mass, which induces isobaric and polyatomic interferences when the ions at the same mass are different chemical species. Last generations of ICP-MS have introduced collision reaction cells. It can in situ reduce these isobaric or polyatomic interferences. The cell is a multipole (quadrupole, hexapole or octupole) device filled with a collision and/or reaction gas. The gas molecules collide or possibly react with the ion beam, which eliminates or reduces interferences. Such resolution of interferences is based on the difference of chemical behaviours between the analyte and the interfering species: the choice of the gas is crucial. A better understanding of the 'ion - gas' reaction should help choosing the reacting gases. Three ICP-MS, with the different cell geometries, were used for this study: Perkin Elmer Elan DRC e (quadrupole), Thermo Fischer X serie II (hexapole) and Agilent Technologies 7700x (octupole). The effects of the cell geometry on different experimental parameters and on the resolution of the 56 Fe + / 40 Ar 16 O + polyatomic interferences were examined to measure iron at trace or ultra-trace level. This preliminary study was applied to measure iron as impurities in uranium oxide, the method was then validated with a Certified Reference Material. The reactivities of transition metals (Zr, Ru, Pd, Ag, Cd, Sn), lanthanides (La, Ce, Nd, Sm, Eu, Gd, Dy, Er and Yb) and actinides (U, Np, Pu, Am and Cm), elements of interest in the nuclear field, are studied with numerous gases (O 2 , CO, CO 2 , N 2

  2. Probabilistic risk assessment on maritime spent nuclear fuel transportation (Part II: Ship collision probability)

    International Nuclear Information System (INIS)

    Christian, Robby; Kang, Hyun Gook

    2017-01-01

    This paper proposes a methodology to assess and reduce risks of maritime spent nuclear fuel transportation with a probabilistic approach. Event trees detailing the progression of collisions leading to transport casks’ damage were constructed. Parallel and crossing collision probabilities were formulated based on the Poisson distribution. Automatic Identification System (AIS) data were processed with the Hough Transform algorithm to estimate possible intersections between the shipment route and the marine traffic. Monte Carlo simulations were done to compute collision probabilities and impact energies at each intersection. Possible safety improvement measures through a proper selection of operational transport parameters were investigated. These parameters include shipment routes, ship's cruise velocity, number of transport casks carried in a shipment, the casks’ stowage configuration and loading order on board the ship. A shipment case study is presented. Waters with high collision probabilities were identified. Effective range of cruising velocity to reduce collision risks were discovered. The number of casks in a shipment and their stowage method which gave low cask damage frequencies were obtained. The proposed methodology was successful in quantifying ship collision and cask damage frequency. It was effective in assisting decision making processes to minimize risks in maritime spent nuclear fuel transportation. - Highlights: • Proposes a probabilistic framework on the safety of spent nuclear fuel transportation by sea. • Developed a marine traffic simulation model using Generalized Hough Transform (GHT) algorithm. • A transportation case study on South Korean waters is presented. • Single-vessel risk reduction method is outlined by optimizing transport parameters.

  3. Effect of nuclear reaction rates on primordial abundances

    International Nuclear Information System (INIS)

    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. 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 has been investigated. Also the study have been taken of these yields as functions of evolution time or temperature. Here it has been found that using these new reaction rates results in only a little increase in helium mass fraction over that obtained previously in BBN calculations. This allows insights into the role of the nuclear reaction rates in the setting of the neutron-to-proton ratio during the BBN epoch. We observe that most of these nuclear reactions have minimal effect on the standard BBN abundance yields of 6 Li and 7 Li

  4. Two-proton correlation functions in nuclear reactions

    International Nuclear Information System (INIS)

    Verde, G.

    2001-01-01

    Full text: Proton-proton correlation functions can be used to study the space-time characteristics of nuclear reactions. For very short-lived sources, the maximum value of the correlation at 20 MeV/c, due to the attractive nature of the S-wave phase shift, provides a unique measure of the size of the emitting source. For long-lived sources, the height of this maximum depends, in addition, on the life time of the source. In this talk, we investigate the common reaction scenario involving both fast dynamical as well as slower emissions from evaporation and/or secondary decays of heavy fragments. We show that the maximum at 20 MeV/c depends both on the source dimension and on the fraction of coincident proton pairs produced in the early stage of the reaction, dominated by fast dynamical preequilibrium emission. The width of the peak at 20 MeV/c, on the other hand, is uniquely correlated to the size of the source. Hence, the size of the emitting source must be extracted from the width or, even better, from the entire shape of the correlation peak, and not from the height. By numerically inverting the measured correlation function, we show that existing data determine only the shape of the fast dynamical source and that its size changes little with proton momenta, contrary to previous analyses with Gaussian sources of zero-lifetime. We further show that the well documented dramatic decrease in the correlation maximum with decreasing total proton momentum reflects directly a corresponding decrease in the fraction of contributing proton pairs from preequilibrium emissions. This provides a powerful method to decompose the proton spectrum into a fraction that originates from fast dynamical emission and a complimentary fraction that originates from slower evaporative emission or secondary decays. We discuss also the comparison of such correlations to transport theories and the generalizations of these techniques to correlations between composite particles. Such studies can

  5. Theoretical investigation of exchange and recombination reactions in O(3P)+NO(2Π) collisions

    International Nuclear Information System (INIS)

    Ivanov, M. V.; Zhu, H.; Schinke, R.

    2007-01-01

    We present a detailed dynamical study of the kinetics of O( 3 P)+NO( 2 Π) collisions including O atom exchange reactions and the recombination of NO 2 . The classical trajectory calculations are performed on the lowest 2 A ' and 2 A '' potential energy surfaces, which were calculated by ab initio methods. The calculated room temperature exchange reaction rate coefficient, k ex , is in very good agreement with the measured one. The high-pressure recombination rate coefficient, which is given by the formation rate coefficient and to a good approximation equals 2k ex , overestimates the experimental data by merely 20%. The pressure dependence of the recombination rate, k r , is described within the strong-collision model by assigning a stabilization probability to each individual trajectory. The measured falloff curve is well reproduced over five orders of magnitude by a single parameter, i.e., the strong-collision stabilization frequency. The calculations also yield the correct temperature dependence, k r ∝T -1.5 , of the low-pressure recombination rate coefficient. The dependence of the rate coefficients on the oxygen isotopes are investigated by incorporating the difference of the zero-point energies between the reactant and product NO radicals, Δ ZPE , into the potential energy surface. Similar isotope effects as for ozone are predicted for both the exchange reaction and the recombination. Finally, we estimate that the chaperon mechanism is not important for the recombination of NO 2 , which is in accord with the overall T -1.4 dependence of the measured recombination rate even in the low temperature range

  6. b-jet tagged nuclear modification factors in heavy ion collisions with CMS

    CERN Document Server

    Jung, Kurt

    2014-01-01

    The energy loss of jets in heavy-ion collisions is expected to depend on the flavor of the fragmenting parton. Thus, measurements of jet quenching as a function of flavor place powerful constraints on the thermodynamical and transport properties of the hot and dense medium. Measurements of the nuclear modification factors of the heavy-flavor-tagged jets in both PbPb and pPb collisions can quantify such energy loss effects. Specifically, pPb measurements provide crucial insights into the behavior of the cold nuclear matter effect, which is required to fully understand the hot and dense medium effects on jets in PbPb collisions. In this talk, we present the b-jet spectra and the first measurement of the nuclear modification factors as a function of transverse momentum and pseudorapidity, using the high statistics pp, pPb and PbPb data taken in 2011 and 2013.

  7. Effect of collision energy and vibrational excitation on endothermic ion-molecule reactions

    International Nuclear Information System (INIS)

    Turner, T.P.

    1984-07-01

    This thesis is divided into two major parts. In the first part an experimental study of proton and deuteron transfer in H 2 + + He and HD + + He has been carried out as a function of kinetic and vibrational energy. The data gives evidence that at lower kinetic energies, the spectator stripping mechanism indeed plays an important role when H 2 + or HD + is vibrationally excited. The second half of this thesis examines the relative efficiencies between the excitation of C-C stretching vibration and collision energy on the promotion of the H atom transfer reaction of C 2 H 2 + + H 2 → C 2 H 3 + + H

  8. Nuclear reactions and synthesis of new transuranium species

    International Nuclear Information System (INIS)

    Seaborg, G.T.

    1983-01-01

    In this short review, I shall describe the special aspects of heavy ion nuclear reaction mechanisms operative in the transuranium region, the role of new techniques, possible nuclear reactions for the production of additional transuranium elements and nuclear species and the importance of work in this region for the development of nuclear models and theoretical concepts. This discussion should make it clear that a continuing supply of leements and isotopes, some fo them relatively short-lived, produced by the HFIR-TRU facilities, will be a requirement for future synthesis of new elements and isotopes

  9. Strangeness production in nuclear collisions: Color rope formations?

    International Nuclear Information System (INIS)

    Toneev, V.D.; Amelin, N.S.; Csernai, L.P.; Gudima, K.K.; Sivoklokov, S.Yu.

    1992-12-01

    Strangeness production at SPS-CERN energies is studied within the Quark Gluon String Model. This analysis indicates that the observed shape of rapidity and transverse mass distributions are reproduced fairly well for both peripheral and central heavy ion collisions. However, for central collisions the model underpredicts strange particles abundance by a factor of about 2:2:4 for K S 0 , Λ and anti Λ, respectively. This discrepancy can be considered as a possible manifestation of string-string interactions of a collective type similar to the formation of a color rope. The model predictions for coming experiments with the Pb beam at CERN are given. (orig.)

  10. Stochastic aspects of multiparticle production in relativistic nuclear reactions

    International Nuclear Information System (INIS)

    Tachung, M.

    1988-01-01

    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

  11. Hadron-nucleus collisions

    International Nuclear Information System (INIS)

    Strugalski, Z.

    1981-01-01

    Qualitative picture of high energy hadron-nucleus collision process, emerging from the analysis of experimental data, is presented. Appropriate description procedure giving a possibility of reproducing various characteristics of this process in terms of the data on elementary hadron-nucleon interaction is proposed. Formula reproducing hadron-nucleus collision cross sections is derived. Inelastic collision cross sections for pion-nucleus and proton-nucleus reactions at wide energy interval are calculated for Pb, Ag, and Al targets. A-dependence of cross sections for pion-nucleus and proton-nucleus collisions at nearly 50 GeV/c momentum were calculated and compared with existing experimental data. Energy dependence of cross sections for hadron-nucleus collisions is determined simply by energy dependence of corresponding cross sections for hadron-nucleon collisions; A-dependence is determined simply by nuclear sizes and nucleon density distributions in nuclei

  12. Transverse energy production in high energy nuclear collisions and the equation of state of nuclear matter

    International Nuclear Information System (INIS)

    Doss, K.G.R.; Gustafsson, H.A.; Gutbrod, H.H.; Kolb, B.; Ludewigt, B.; Poskanzer, A.M.; Ritter, H.G.; Schmidt, H.R.; Lawrence Berkeley Lab., CA; Kampert, K.H.; Loehner, H.

    1987-08-01

    In nuclear collisions of AU+Au, Nb+Nb and Ca+Ca at bombarding energies between 150 and 800 MeV per nucleon transverse energy and transverse momenta of light particles are studied event by event at θ = 90 0 in the center of mass system. At all energies a rise of the mean transverse energy per nucleon is observed with increasing charged particle multiplicity. Particularly large values of E perpendicular to have been found for 3 He-fragments. The hydrodynamical picture is discussed for a possible separation of the collective flow and the thermal parts of the E perpendicular to -spectrum. From this, evidence for a rather stiff equation of state is found. (orig.)

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

    CERN Document Server

    Duarte, H

    2010-01-01

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

  14. Charged particle-induced nuclear fission reactions

    Indian Academy of Sciences (India)

    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 ...

  15. On the nuclear fragmentation mechanisms in nuclear collisions at intermediate and high energies

    International Nuclear Information System (INIS)

    Jipa, Al; Besliu, C.; Felea, D.

    2004-01-01

    The nuclear fragmentation mechanisms can be discussed by taking into account different scales related to the fragment sizes. Considering two fragmentation mechanisms of the nuclei at the same incident energy an analysis of the experimental results obtained was done. Goldhaber formula was improved by analyzing the discrepancies between data and theories concerning the projectile fragmentation. We implied that the projectile fragmentation process would be governed by the distribution of nucleon momenta in the projectile after the collision occurred. We used in our analysis protons from the 4 He + 7 Li at 4.5 GeV/c per nucleon incident momentum, as well as from 40 Ar + 12 C at 213 AMeV bombarding energy. We proved that in order to proceed in analyzing the projectile fragmentation process at intermediate and high energies one has to consider the dependence σ 0 on the apparent temperature of projectile nucleus after the collision took place. The generalized Bertsch correction for light projectile nuclei and fragments was used and the number of spatial correlations between identical nucleons having anticorrelated momenta was found. Thus we found apparent temperature values close to the separation energies of the considered fragments per number of fragments. The temperatures associated to kinetic energy spectra of the projectile fragments were calculated following two methods. The results from Bauer's method were compared with those obtained by fitting the kinetic energy distributions of the projectile fragments in the rest frame of the projectile with a Maxwellian curve. We also accomplished the comparison of the experimental results with similar events simulated with RQMD 2.4. All the results obtained suggested two nuclear fragmentation mechanisms: a sudden fragmentation by explosive mechanisms, like shock waves and a slow fragmentation by the 'fission' of the spectator regions, mainly because of the interactions with the particles or fragments emitted from the

  16. Specialized reactions: reactions at intermediate energies: Baryon--nucleus collisions, 150 MeV--1 GeV

    International Nuclear Information System (INIS)

    Igo, G.

    1974-01-01

    The high energy collision approximation proposed by Glauber to describe experimental data at the upper end of the intermediate range is reviewed. Some aspects of the model which limit its validity are outlined. Elastic scattering of protons from light nuclei is discussed in the framework of the Glauber model. For data in the energy region near 200 MeV, the plane wave impulse approximation (PWIA) and the distorted wave impulse approximation (DWIA) are applied. Quasielastic scattering is treated by considering (p,p') and (p,2p) reactions with light nuclei. A short discussion of the high resolution spectrometer facility at LAMPF and the SPES 1 facility at Saturne is given. (46 figures, 3 tables, 102 references) (U.S.)

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

    International Nuclear Information System (INIS)

    Dean, D J

    2006-01-01

    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

  18. 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.

  19. Analysis by nuclear reactions and activations. A current bibliography

    International Nuclear Information System (INIS)

    Bujdoso, E.

    2001-01-01

    A current bibliography based on INIS Atomindex with 78 references on Analysis by nuclear reactions and activations has been prepared for year 1998. References are arranged by first authors' name. (N.T.)

  20. Photoneutron Reaction Data for Nuclear Physics and Astrophysics

    Directory of Open Access Journals (Sweden)

    Utsunomiya Hiroaki

    2018-01-01

    Full Text Available We discuss the role of photoneutron reaction data in nuclear physics and astrophysics in conjunction with the Coordinated Research Project of the International Atomic Energy Agency with the code F41032 (IAEA-CRP F41032.

  1. Low-energy nuclear reactions with double-solenoid- based ...

    Indian Academy of Sciences (India)

    solenoids to produce low-energy radioactive nuclear beams. In these systems the ... For many years, the disadvantage in these investigations ... fusion or breakup reaction, preferred with large forward-peaked cross-sections. To transfer the ...

  2. Photopion reactions, a probe for nuclear critical opalescence

    International Nuclear Information System (INIS)

    Delorme, J.

    1980-07-01

    It is shown that photopion reactions are a good probe of the nuclear pion field for momenta characteristic of pion condensation. They are thus a direct detector of critical opalescence. Best conditions for experimental detection are discussed

  3. Photoneutron Reaction Data for Nuclear Physics and Astrophysics

    Science.gov (United States)

    Utsunomiya, Hiroaki; Renstrøm, Therese; Tveten, Gry Merete; Gheorghe, Ioana; Filipescu, Dan Mihai; Belyshev, Sergey; Stopani, Konstantin; Wang, Hongwei; Fan, Gongtao; Lui, Yiu-Wing; Symochko, Dmytro; Goriely, Stephane; Larsen, Ann-Cecilie; Siem, Sunniva; Varlamov, Vladimir; Ishkhanov, Boris; Glodariu, Tudor; Krzysiek, Mateusz; Takenaka, Daiki; Ari-izumi, Takashi; Amano, Sho; Miyamoto, Shuji

    2018-05-01

    We discuss the role of photoneutron reaction data in nuclear physics and astrophysics in conjunction with the Coordinated Research Project of the International Atomic Energy Agency with the code F41032 (IAEA-CRP F41032).

  4. Nuclear fragmentation in central collisions: Ni + Au from 32 to 90 A*MeV

    International Nuclear Information System (INIS)

    Bellaize, N.

    2000-01-01

    Heavy ion collisions are one of tools for studying nuclear system far away from its equilibrium state. This work concerns the most violent collisions in the Ni + Au system for incident energies ranging from 32 up to 90 AMeV. These events were detected with the multidetector INDRA and selected by the Principal Component Analysis (multidimensional analysis). This method classifies the events according their detection features and their degree of dissipation. We observed two deexcitation mechanisms: a fusion/fission - evaporation process and a multifragmentation process. Those two coexist from 32 to 52 AMeV whereas only one subsists at 90 AMeV. For those two mechanisms, an component was observed which seems to be linked to the initial phase of the reaction. The energy fluctuations of this component leads to variations in the energy deposit which determines the deexcitation of the system. The experimental multifragmentation data of the Ni + Au system (52 and 90 AMeV) were compared to the predictions of a statistical model and to the experimental data of the system Xe + Sn at 50 AMeV (also detected with INDRA). These comparisons show the lack of collective radial energy for fragments (Z≥10) in the Ni + Au system, and show that the degree of multifragmentation depends of the thermal excitation energy. Mean kinetic energies of particles and lights fragments (Z≥10) are larger in the Ni + Au system than the Xe + Sn system. This observation shows that these particles are more sensitive to the entrance channel for an asymmetric system than for a symmetric system (for the same number of nucleons). (author)

  5. Applications of Boltzmann Langevin equation to nuclear collisions

    International Nuclear Information System (INIS)

    Suraud, E.; Belkacem, M.; Stryjewski, J.; Ayik, S.

    1991-01-01

    An approximate method for obtaining numerical solutions of the Boltzmann-Langevin equation is proposed. The method is applied to calculate the time evolution of the mean value and dispersion of the quadrupole and octupole moments of the momentum distribution in nucleus-nucleus collisions, and some consequences are discussed

  6. Theoretical trends in interferometry of ultrarelativistic nuclear collisions

    International Nuclear Information System (INIS)

    Padula, S.S.

    1990-01-01

    A review is made of the main concepts of interferometry, since its discovery in the mid 50's as the HBT effect, until recently, where some new approaches to the field were suggested. A few modifications on the correlation function in the case of high energy collisions are discussed and illustrated. (author)

  7. Bimodality: A Sign of Critical Behavior in Nuclear Reactions

    International Nuclear Information System (INIS)

    Le Fevre, A.; Aichelin, J.

    2008-01-01

    The recently discovered coexistence of multifragmentation and residue production for the same total transverse energy of light charged particles, which has been dubbed bimodality like it has been introduced in the framework of equilibrium thermodynamics, can be well reproduced in numerical simulations of heavy ion reactions. A detailed analysis shows that fluctuations (introduced by elementary nucleon-nucleon collisions) determine which of the exit states is realized. Thus, we can identify bifurcation in heavy ion reactions as a critical phenomenon. Also the scaling of the coexistence region with beam energy is well reproduced in these results from the quantum molecular dynamics simulation program

  8. Computing the cross sections of nuclear reactions with nuclear clusters emission for proton energies between 30 MeV and 2.6 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Korovin, Yu. A.; Maksimushkina, A. V., E-mail: AVMaksimushkina@mephi.ru; Frolova, T. A. [Obninsk Institute for Nuclear Power Engineering, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation)

    2016-12-15

    The cross sections of nuclear reactions involving emission of clusters of light nuclei in proton collisions with a heavy-metal target are computed for incident-proton energies between 30 MeV and 2.6 GeV. The calculation relies on the ALICE/ASH and CASCADE/INPE computer codes. The parameters determining the pre-equilibrium cluster emission are varied in the computation.

  9. Signatures of quantum radiation reaction in laser-electron-beam collisions

    International Nuclear Information System (INIS)

    Wang, H. Y.; Yan, X. Q.; Zepf, M.

    2015-01-01

    Electron dynamics in the collision of an electron beam with a high-intensity focused ultrashort laser pulse are investigated using three-dimensional QED particle-in-cell (PIC) simulations, and the results are compared with those calculated by classical Landau and Lifshitz PIC simulations. Significant differences are observed from the angular dependence of the electron energy distribution patterns for the two different approaches, because photon emission is no longer well approximated by a continuous process in the quantum radiation-dominated regime. The stochastic nature of photon emission results in strong signatures of quantum radiation-reaction effects under certain conditions. We show that the laser spot size and duration greatly influence these signatures due to the competition of QED effects and the ponderomotive force, which is well described in the classical approximation. The clearest signatures of quantum radiation reaction are found in the limit of large laser spots and few cycle pulse durations

  10. Reaction mechanisms in collisions induced by $^{8}$B beam close to the barrier

    CERN Multimedia

    The aim of the proposed experiment is to investigate the reaction dynamics of proton-halo induced collisions at energies around the Coulomb barrier where coupling to continuum effects are expected to be important. We propose to measure the $^{8}$B + $^{64}$Zn elastic scattering angular distribution together with the measurement, for the first time, of p - $^{7}$Be coincidences coming from transfer and/or break-up of $^{8}$B. The latter will allow a better understanding of the relative contribution of elastic $\\textit{vs}$ non-elastic break-up in reactions induced by extremely weakly-bound nuclei. We believe that with the availability of the post accelerated $^{8}$B beam at REX-ISOLDE we will be able to collect for the first time high quality data for the study of such an important topic.

  11. Nuclear stopping in oxygen-induced reactions at 200 A GeV

    International Nuclear Information System (INIS)

    Obenshain, F.E.; Albrecht, R.; Awes, T.C.

    1988-01-01

    A primary goal of relativistic heavy-ion studies is to verify the existence of the postulated quark-gluon plasma (QGP). Since most of the possible plasma signatures are indistinguishable from background created by nonplasma events. Thorough understanding of reaction mechanisms is an important prerequisite in any QGP search. To isolate collective features of nucleus-nucleus collisions from those that may be expected on the basis of linear superposition of nucleon-nucleus collisions, we compare measured quantities with calculations that reproduce data from nucleon-induced reactions and that make predictions for nucleus-nucleus reactions. Here we discuss the data obtained from our Zero-Degree Calorimeter (ZDC) and the transverse energy obtained from the Mid-Rapidity Calorimeter (MIRAC). The primary reactions considered are: 16 O + 16 C and 16 O + 197 Au. The measurements show a high degree of nuclear stopping and the energy densities may be large enough to produce a transition to the quark-gluon plasma. 10 refs., 5 figs

  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. Electromagnetic studies of nuclear structure and reactions

    International Nuclear Information System (INIS)

    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

  14. Characteristics of particle production in high energy nuclear collisions a model-based analysis

    CERN Document Server

    Guptaroy, P; Bhattacharya, S; Bhattacharya, D P

    2002-01-01

    The present work pertains to the production of some very important negatively charged secondaries in lead-lead and gold-gold collisions at AGS, SPS and RHIC energies. We would like to examine here the role of the particular version of sequential chain model (SCM), which was applied widely in the past in analysing data on various high-energy hadronic collisions, in explaining now the latest findings on the features of particle production in the relativistic nucleus-nucleus collisions. The agreement between the model of our choice and the measured data is found to be modestly satisfactory in cases of the most prominent and abundantly produced varieties of the secondaries in the above-stated two nuclear collisions. (25 refs).

  15. Low Energy Nuclear Reaction Products at Surfaces

    Science.gov (United States)

    Nagel, David J.

    2008-03-01

    This paper examines the evidence for LENR occurring on or very near to the surface of materials. Several types of experimental indications for LENR surface reactions have been reported and will be reviewed. LENR result in two types of products, energy and the appearance of new elements. The level of instantaneous power production can be written as the product of four factors: (1) the total area of the surface on which the reactions can occur, (2) the fraction of the area that is active at any time, (3) the reaction rate, that is, the number of reactions per unit active area per second, and (4) the energy produced per reaction. Each of these factors, and their limits, are reviewed. A graphical means of relating these four factors over their wide variations has been devised. The instantaneous generation of atoms of new elements can also be written as the product of the first three factors and the new elemental mass produced per reaction. Again, a graphical means of presenting the factors and their results over many orders of magnitude has been developed.

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

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    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{sup +}e{sup {minus}} problem and heavy ion dynamics.

  17. Theoretical studies in nuclear reactions and nuclear structure

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    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{sup +}e{sup {minus}} problem and heavy ion dynamics.

  18. Theoretical studies in nuclear reactions and nuclear structure

    International Nuclear Information System (INIS)

    1992-05-01

    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

  19. Nuclear targets, recoil ion catchers and reaction chambers

    NARCIS (Netherlands)

    Dionisio, JS; Vieu, C; Schuck, C; Collatz, R; Meunier, R; Ledu, D; Folger, H; Lafoux, A; Lagrange, JM; Pautrat, M; Waast, B; Phillips, WR; Blunt, D; Durell, JL; Varley, BJ; Dagnall, PG; Dorning, SJ; JONES, MA; Smith, AG; Bacelar, JCS; Rzaca-Urban, T; Amzal, N; Meliani, Z; Vanhorenbeeck, J; Passoja, A; Urban, W

    1998-01-01

    The main features of nuclear targets, recoil ion catchers and reaction chambers used in nuclear spectroscopic investigations involving in-beam multi-e-gamma spectrometers are discussed. The relative importance of the F-ray background due to the accelerated ion-target and the recoil-ion-target

  20. A workshop report on nuclear reaction and cluster structure

    International Nuclear Information System (INIS)

    1985-01-01

    A work shop was held in June 1984 at RCNP (Research Center for Nuclear Physics), Osaka University, to discuss theory of nuclear reactions based on studies from microscopic or cluster structure viewpoints. About forty researchers participated in this work shop and 27 paperes were presented. All these papers with English abstracts are gathered in this collective report. (Aoki, K.)

  1. 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)

    2001-01-01

    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 [ru

  2. Scaling of charged particle multiplicity distributions in relativistic nuclear collisions

    International Nuclear Information System (INIS)

    Ahamd, N.; Hushnud; Azmi, M.D.; Zafar, M.; Irfan, M.; Khan, M.M.; Tufail, A.

    2011-01-01

    Validity of KNO scaling in hadron-hadron and hadron-nucleus collisions has been tested by several workers. Multiplicity distributions for p-emulsion interactions are found to be consistent with the KNO scaling hypothesis for pp collisions. The applicability of the scaling law was extended to FNAL energies by earlier workers. Slattery has shown that KNO scaling hypothesis is in fine agreement with the data for pp interactions over a wide range of incident energies. An attempt, is, therefore, made to examine the scaling hypothesis using multiplicity distributions of particles produced in 3.7A GeV/c 16 O-, 4.5A GeV/c and 14.5A GeV/c 28 Si - nucleus interactions

  3. Nuclear shape evolution starting from superdeformed state. Role of two-body collision and rotation

    International Nuclear Information System (INIS)

    Liu, Yu-xin; Sakata, Fumihiko

    1999-01-01

    With the nuclear density distribution being simulated by the Boltzmann Uehling-Uhlenbeck equation and Vlasov equation with several rotational frequencies, the time evolution of the quadrupole moment of nucleus 86 Zr starting with superdeformed shape is studied. The contribution of two-body collisions and the effects of collective rotation to the shape evolution is investigated. The numerical results indicate that the two-body collisions play a role of damping on the evolution from a superdeformed shape to a normal deformed one in a case without rotation. In a case of rotation with lower frequency, the two-body collisions accelerate the evolution process. A new role of the collective rotation to enhance the nuclear fission is proposed. (author)

  4. Direct reactions for nuclear structure and nuclear astrophysics

    International Nuclear Information System (INIS)

    Jones, Katherine Louise

    2014-01-01

    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 108,106 Sn at the NSCL, and on 131 Sn at HRIBF are presented as well as the results from the nucleosynthesis study.

  5. Direct Reactions for Nuclear Structure and Nuclear Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Katherine Louise [Univ. of Tennessee, Knoxville, TN (United States). Experimental Low-Energy Nuclear Physics Group

    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.

  6. SkyNet: A Modular Nuclear Reaction Network Library

    Science.gov (United States)

    Lippuner, Jonas; Roberts, Luke F.

    2017-12-01

    Almost all of the elements heavier than hydrogen that are present in our solar system were produced by nuclear burning processes either in the early universe or at some point in the life cycle of stars. In all of these environments, there are dozens to thousands of nuclear species that interact with each other to produce successively heavier elements. In this paper, we present SkyNet, a new general-purpose nuclear reaction network that evolves the abundances of nuclear species under the influence of nuclear reactions. SkyNet can be used to compute the nucleosynthesis evolution in all astrophysical scenarios where nucleosynthesis occurs. SkyNet is free and open source, and aims to be easy to use and flexible. Any list of isotopes can be evolved, and SkyNet supports different types of nuclear reactions. SkyNet is modular so that new or existing physics, like nuclear reactions or equations of state, can easily be added or modified. Here, we present in detail the physics implemented in SkyNet with a focus on a self-consistent transition to and from nuclear statistical equilibrium to non-equilibrium nuclear burning, our implementation of electron screening, and coupling of the network to an equation of state. We also present comprehensive code tests and comparisons with existing nuclear reaction networks. We find that SkyNet agrees with published results and other codes to an accuracy of a few percent. Discrepancies, where they exist, can be traced to differences in the physics implementations.

  7. Probing vacuum structure in nuclear collisions. Research report period: 1992--1995

    International Nuclear Information System (INIS)

    Rafelski, J.

    1995-02-01

    This is a report of the research activities in the field of Relativistic Nuclear Collisions/Theoretical Nuclear Physics of Johann Refelski at University of Arizona, supported by the Department of Energy, Nuclear Physics Division under grant No. DE-FG02-92ER40733. This report comprises: Section 1 surveys the general context of the work and presents summary of wider research objectives; Section 2 reviews the progress in the interpretation of experimental data, primarily related to diagnosis of high density nuclear matter with strange particle production, in heavy ion collisions at 10--200 GeV A; Section 3 presents the status of the studies of a relativistic quantum transport theory and the related vacuum structure and particle production processes; Section 4 presents a compilation of research projects completed under auspices of this program, with a short narrative description of publication contents

  8. Nuclear reactions: Science and trans-science

    International Nuclear Information System (INIS)

    Weinberg, A.M.

    1992-01-01

    This book is a collection of essays written by Weinberg over the span of his scientific and administrative career. A sound theorist, he was introduced to nuclear physics as part of the Manhattan project, and assumed administrative responsibilities during that project. His career has allowed him to make valuable contributions in a broad range of fields. These essays touch on topics of interest to him, concern to the country, and of profound import for society as it exists today. They are grouped into five sections: science and trans-science; scientific administration; strategic defense and arms control; time, energy and resources; nuclear energy

  9. Resonance reactions and enhancement of weak interactions in collisions of cold molecules

    International Nuclear Information System (INIS)

    Flambaum, V. V.; Ginges, J. S. M.

    2006-01-01

    With the creation of ultracold atoms and molecules, a new type of chemistry - 'resonance' chemistry - emerges: chemical reactions can occur when the energy of colliding atoms and molecules matches a bound state of the combined molecule (Feshbach resonance). This chemistry is rather similar to reactions that take place in nuclei at low energies. In this paper we suggest some problems for future experimental and theoretical work related to the resonance chemistry of ultracold molecules. Molecular Bose-Einstein condensates are particularly interesting because in this system collisions and chemical reactions are extremely sensitive to weak fields; also, a preferred reaction channel may be enhanced due to a finite number of final states. The sensitivity to weak fields arises due to the high density of narrow compound resonances and the macroscopic number of molecules with kinetic energy E=0 (in the ground state of a mean-field potential). The high sensitivity to the magnetic field may be used to measure the distribution of energy intervals, widths, and magnetic moments of compound resonances and study the onset of quantum chaos. A difference in the production rate of right-handed and left-handed chiral molecules may be produced by external electric E and magnetic B fields and the finite width Γ of the resonance (correlation ΓE·B). The same effect may be produced by the parity-violating energy difference in chiral molecules

  10. Observation of strong azimuthal asymmetry between slow and fast particles from high energy nuclear collisions

    International Nuclear Information System (INIS)

    Gustafsson, H.A.; Gutbrod, H.H.; Kolb, B.; Loehner, H.; Ludewigt, B.; Poskanzer, A.M.; Renner, T.; Riedesel, H.; Ritter, H.G.; Siemiarczuk, T.; Stepaniak, J.; Warwick, A.; Wieman, H.

    1984-10-01

    Evidence is presented for the strong azimuthal asymmetry between slow and fast fragments in nuclear collisions in the energy interval of 0.4 to 1 GeV per nucleon. The asymmetry gets stronger when incident energy and impact parameter decrease. The results on the A dependence of the azimuthal asymmetry are also presented. (orig.)

  11. Heavy-flavor production and medium properties in high-energy nuclear collisions --What next?

    NARCIS (Netherlands)

    Aarts, G.; Aichelin, J.; Allton, C.; Arnaldi, R.; Bass, S. A.; Bedda, C.; Brambilla, N.; Bratkovskaya, E.; Braun-Munzinger, P.; Bruno, G. E.; Dahms, T.; Das, S. K.; Dembinski, H.; Djordjevic, M.; Ferreiro, E. G.; Frawley, A.; Gossiaux, P. B.; Granier de Cassagnac, R.; Grelli, A.; He, Ming; Horowitz, W. A.; Innocenti, G. M.; Jo, M.; Kaczmarek, O.; Kuijer, P; Laine, M.; Lombardo, M. P.; Mischke, A.; Munhoz, M. G.; Nahrgang, M.; Nguyen, Mai; Oliveira da Silva, A. C.; Petreczky, P.; Rothkopf, A.; Schmelling, M.; Scomparin, E.; Song, Ting; Stachel, J.; Suaide, A. A P; Tolos, L.; Trzeciak, B.; Uras, A.; van Doremalen, L.; Vermunt, L.; Vigolo, S.; Xu, N.; Ye, Z.; Zanoli, H.J.C.; Zhuang, P.

    2017-01-01

    Open and hidden heavy-flavor physics in high-energy nuclear collisions are entering a new and exciting stage towards reaching a clearer understanding of the new experimental results with the possibility to link them directly to the advancement in lattice Quantum Chromo-Dynamics (QCD). Recent results

  12. Astrophysical Nuclear Reaction Rates in the Dense Metallic Environments

    Science.gov (United States)

    Kilic, Ali Ihsan

    2017-09-01

    Nuclear reaction rates can be enhanced by many orders of magnitude in dense and relatively cold astrophysical plasmas such as in white dwarfs, brown dwarfs, and giant planets. Similar conditions are also present in supernova explosions where the ignition conditions are vital for cosmological models. White dwarfs are compact objects that have both extremely high interior densities and very strong local magnetic fields. For the first time, a new formula has been developed to explain cross section and reaction rate quantities for light elements that includes not only the nuclear component but also the material dependence, magnetic field, and crystal structure dependency in dense metallic environments. I will present the impact of the developed formula on the cross section and reaction rates for light elements. This could have possible technological applications in energy production using nuclear fusion reactions.

  13. Nuclear Reaction and Structure Databases of the National Nuclear Data Center

    International Nuclear Information System (INIS)

    Pritychenko, B.; Arcilla, R.; Herman, M. W.; Oblozinsky, P.; Rochman, D.; Sonzogni, A. A.; Tuli, J. K.; Winchell, D. F.

    2006-01-01

    The National Nuclear Data Center (NNDC) collects, evaluates, and disseminates nuclear physics data for basic research and applied nuclear technologies. In 2004, the NNDC migrated all databases into modern relational database software, installed new generation of Linux servers and developed new Java-based Web service. This nuclear database development means much faster, more flexible and more convenient service to all users in the United States. These nuclear reaction and structure database developments as well as related Web services are briefly described

  14. The mechanism of nuclear energy release in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Strugalski, Z.; Strugalska-Gola, E.

    1998-01-01

    The mechanism of intranuclear energy release in reactions induced by nucleus-nucleus collisions at energies higher than ∼ 0.5 GeV/nucl. is presented - as prompted experimentally. The intranuclear energy release goes through local damages of the colliding nuclei

  15. Study of the reactions resulting in heavy fragment formation in the collisions 40Ar + Cu, Ag and Au at 8 to 115 MeV/u

    International Nuclear Information System (INIS)

    Colin, Eric Yves

    1998-01-01

    This work concerns the study of nuclear collisions showing a heavy fragment in 40 Ar + Cu, Ag and Au from 8 A MeV to 115 A MeV. The reactions are classified by centrality or collision violence via the multiplicity of charged particles detected in a 4π array. For the most peripheral reactions (low multiplicities) we always find a projectile-like fragment with velocity near to that of the beam and a heavy target-like fragment with very small velocity. For the more central collisions we find the well-known incomplete fusion reactions at 17 and 27 A MeV. Above 27 A MeV two groups of very dissipative reactions are observed, both with high charged particle multiplicities. The first reaction group forms several fragments with Z ≤ 10 and average longitudinal velocity near to that of c.m. These are very rare, and are found only for the highest 1% of multiplicities. They produce a heavy fragment and a forward spray (θ≤60 angle) of particles with charge going from 1 to ≅13. The momentum carried out by the spray is randomly spread over all the particles. In spite of the increase of momentum carried by this spray with increasing beam energy, a heavy emission source is formed with 1 - 2 GeV of excitation energy. After a phase of expansion, especially signaled by Z = 1 particles, this source then evaporates many particles. Finally we observed the remaining heavy residual nucleus. (author)

  16. Intensity-interferometric test of nuclear collision geometries obtained from the Boltzmann-Uehling-Uhlenbeck equation

    International Nuclear Information System (INIS)

    Gong, W.G.; Bauer, W.; Gelbke, C.K.; Carlin, N.; de Souza, R.T.; Kim, Y.D.; Lynch, W.G.; Murakami, T.; Poggi, G.; Sanderson, D.P.; Tsang, M.B.; Xu, H.M.; Pratt, S.; Fields, D.E.; Kwiatkowski, K.; Planeta, R.; Viola, V.E. Jr.; Yennello, S.J.

    1990-01-01

    Two-proton correlation functions measured for the 14 N+ 27 Al reaction at E/A=75 MeV are compared to correlation functions predicted for collision geometries obtained from numerical solutions of the Boltzmann-Uehling-Uhlenbeck (BUU) equation. The calculations are in rather good agreement with the experimental correlation function, indicating that the BUU equation gives a reasonable description of the space-time evolution of the reaction

  17. Whole study of nuclear matter collective motion in central collisions of heavy ions of the FOPI detector; Etude complete du mouvement collectif de la matiere nucleaire dans les collisions centrales d'ions lourds avec le detecteur FOPI

    Energy Technology Data Exchange (ETDEWEB)

    Bendarag, A

    1999-07-09

    In this work we study the collective phenomena in the central collisions of heavy ions for the Au + Au, Xe + CsI and Ni + Ni systems at incident energies from 150 to 400 MeV/nucleon with the data of the FOPI detector. In order to describe completely the flow of the nuclear matter, we fit the double differential momentum distributions with two-dimensional Gaussian. We study the characteristic parameters of the collective flow (flow range, aspect ratios, flow parameter) versus the charge and the mass of the fragments as well as the incident energy and the centrality of the collisions. The transverse energy is used for selecting the central collisions. The method of the Gaussian fits requires also to reconstruct the reaction plane of the event. Then we correct the parameters for the finite number of particles effects and account for the influence of the acceptance of the detector. We confirm the importance of the thermal motion for the light charge or mass fragments and, conversely, the predominance of the collective motion for the heavy fragments. A common flow angle for all the types of particles is highlighted for the first time, demonstrating the power of the method of the Gaussian fits; The evolution of the other parameters confirms the observations done with other methods of flow analysis. These results should contribute to put constraints on the collision models and to enlarge our knowledge of the properties of the nuclear matter. (author)

  18. Status of CONRAD, a nuclear reaction analysis tool

    International Nuclear Information System (INIS)

    Saint Jean, C. de; Habert, B.; Litaize, O.; Noguere, G.; Suteau, C.

    2008-01-01

    The development of a software tool (CONRAD) was initiated at CEA/Cadarache to give answers to various problems arising in the data analysis of nuclear reactions. This tool is then characterized by the handling of uncertainties from experimental values to covariance matrices for multi-group cross sections. An object oriented design was chosen allowing an easy interface with graphical tool for input/output data and being a natural framework for innovative nuclear models (Fission). The major achieved developments are a data model for describing channels, nuclear reactions, nuclear models and processes with interface to classical data formats, theoretical calculations for the resolved resonance range (Reich-Moore) and unresolved resonance range (Hauser-Feshbach, Gilbert-Cameron,...) with nuclear model parameters adjustment on experimental data sets and a Monte Carlo method based on conditional probabilities developed to calculate properly covariance matrices. The on-going developments deal with the experimental data description (covariance matrices) and the graphical user interface. (authors)

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

    International Nuclear Information System (INIS)

    Otsuka, N.; Semkova, V.; Simakov, S.P.; Zerkin, V.

    2011-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, N; Semkova, V; Simakov, S P; Zerkin, V [Nuclear Data Services Unit, Nuclear Data Section, IAEA, Vienna (Austria)

    2011-11-15

    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.

  1. Enhancement mechanisms of low energy nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Gareev, F. A.; Zhidkova, I.E.; Ratis, Yu.L. [Joint Institute for Nuclear Research, JINR, 6 Joliot Curie Street, Dubna, Moscow Region 141980 (Russian Federation)

    2006-07-01

    The full review of Russian low energy nuclear reactors is represented. We have concluded that transmutation of nuclei at low energies, LENR, is possible in the framework of the modern physical theory - excitation and ionization of atoms and universal resonance synchronization principle are responsible for it. Investigation of this phenomenon requires knowledge of different branches of 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 reproducibility of experimental data is due to the fact that LENR occurs in open systems and it is extremely sensitive to parameters of external fields and systems. Classical reproducibility principle should be reconsidered for LENR experiments. Poor reproducibility and unexplained results do not means that the experiment is wrong.

  2. Enhancement mechanisms of low energy nuclear reactions

    International Nuclear Information System (INIS)

    Gareev, F. A.; Zhidkova, I.E.; Ratis, Yu.L.

    2006-01-01

    The full review of Russian low energy nuclear reactors is represented. We have concluded that transmutation of nuclei at low energies, LENR, is possible in the framework of the modern physical theory - excitation and ionization of atoms and universal resonance synchronization principle are responsible for it. Investigation of this phenomenon requires knowledge of different branches of 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 reproducibility of experimental data is due to the fact that LENR occurs in open systems and it is extremely sensitive to parameters of external fields and systems. Classical reproducibility principle should be reconsidered for LENR experiments. Poor reproducibility and unexplained results do not means that the experiment is wrong

  3. Direct photons in nuclear collisions at fair energies

    International Nuclear Information System (INIS)

    Kiselev, S. M.

    2009-01-01

    Using the extrapolation of existing data, estimations of prompt-photon production at FAIR energies have been made. At y = y c.m. the rapidity density of prompt photons with p t > 1.5 GeV/c per central Au + Au event at 25 A GeV is estimated as ∼10 -4 . With the planned beam intensity 10 9 per second and 1% interaction probability, for 10% of most central events one can expect the prompt-photon rate ∼10 2 photons per second. Direct photons from the hadron scenario of ion collisions generated by the Hadron-String-Dynamics (HSD) transport approach with implemented meson scatterings πρ → πγ, ππ → ργ have been analyzed. Photons from short-living resonances (e.g., ω → π 0 γ) decaying during the dense phase of the collision should be considered as direct photons. They contribute significantly in the direct photon spectrum at p t = 0.5-1 GeV/c. At the FAIR energy 25 A GeV in Au + Au central collisions the HSD generator predicts, as a lower estimate, γ direct /γ ( π 0 ) ≅ 0.5% in the region p t = 0.5-1 GeV/c. At p t = 1.5-2 GeV/c γ prompt / γ ( π 0 ) ≅ 2%. Thermal direct photons have been evaluated with the Bjorken Hydro-Dynamics (BHD) model. The BHD spectra differ strongly from the HSD predictions. The direct-photon spectrum is very sensitive to the initial temperature parameter T 0 of the model. The 10-MeV increase in the T 0 value leads to ∼2 times higher photon yield.

  4. Theoretical interpretation of high-energy nuclear collisions

    International Nuclear Information System (INIS)

    Fai, G.

    1990-08-01

    In the following, I briefly summarize the research results and progress under this project in the time period January 1, 1988--July 31, 1990. Published and unpublished research in this time period focused on aspects of nuclear disassembly, nuclear dynamics, and subnucleonic degrees of freedom in model field theories

  5. Linear cascade calculations of matrix due to neutron-induced nuclear reactions

    International Nuclear Information System (INIS)

    Avila, Ricardo E

    2000-01-01

    A method is developed to calculate the total number of displacements created by energetic particles resulting from neutron-induced nuclear reactions. The method is specifically conceived to calculate the damage in lithium ceramics by the 6L i(n, α)T reaction. The damage created by any particle is related to that caused by atoms from the matrix recoiling after collision with the primary particle. An integral equation for that self-damage is solved by interactions, using the magic stopping powers of Ziegler, Biersack and Littmark. A projectile-substrate dependent Kinchin-Pease model is proposed, giving and analytic approximation to the total damage as a function of the initial particle energy (au)

  6. Accessing the nuclear symmetry energy in Ca+Ca collisions

    Directory of Open Access Journals (Sweden)

    Chbihi A.

    2012-07-01

    Full Text Available The status of the analysis of the INDRA-VAMOS experiement performed at GANIL, using the reactions 40,48Ca+40,48Ca reactions at 35AMeV, are presented. Isotopic distributions of fragments produced in multifragmentation events provide information on the importance of the surface term contribution in the symmetry energy by comparison to AMD predictions.

  7. [Studies of target fragmentation in intermediate energy, relativistic and ultra-relativistic nuclear collisions]. Nuclear chemistry progress report, August 1, 1990--August 1, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Loveland, W.D.

    1991-08-01

    The work described herein is part of a project involving the study of low energy (< 10 MeV/A), intermediate energy (10--100 MeV/A) and relativistic (> 250 MeV/A) heavy ion reactions. In the low energy regime, we published a monograph on the properties of the heaviest elements and used that publication as a basis for making a set of ``best`` semi-empirical predictions of heavy element decay properties. The intermediate energy research effort focussed upon the completion of studies already begun and the initiation of a number of new experiments. In our study of a interaction of 21 MeV/nucleon {sup 129}Xe with {sup 197}Au, we compared the characteristics of the observed deep inelastic phenomena with various models of dissipative reactions and found significant discrepancies between observations and predictions. These discrepancies seemed to be caused by an improper treatment of pre-equilibrium in the early stages of the collision. In our study of the relativistic interaction of 400 MeV/nucleon {sup 12}C with {sup 197}Au, we reported the first direct physical measurement of the properties of the spallation residues from a nucleus-nucleus collision. We found the residue energies to be much lower than those predicted by the intranuclear cascade model, indicating some substantial modifications of that model are needed. But, we also found, indications of significant, non-zero values of the residue transverse momentum, a finding that calls into question the interpretation of a number of radiochemical recoil studies of the kinematics of high energy reactions. A program of performing numerical simulations of intermediate and high energy nuclear collisions using the QMD model was initiated.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

    Context. 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. Aims. The reaction code TALYS has been recently updated to estimate the Maxwellian-averaged reaction rates that are of astrophysical relevance. These new developments enable the reaction rates to be calculated with increased accuracy and reliability and the approximations of previous codes to be investigated. Methods. The TALYS predictions for the thermonuclear rates of relevance to astrophysics are detailed and compared with those derived by widely-used codes for the same nuclear ingredients. Results. It is shown that TALYS predictions may differ significantly from those of previous codes, in particular for nuclei for which no or little nuclear data is available. The pre-equilibrium process is shown to influence the astrophysics rates of exotic neutron-rich nuclei significantly. For the first time, the Maxwellian- averaged (n, 2n) reaction rate is calculated for all nuclei and its competition with the radiative capture rate is discussed. Conclusions. The TALYS code provides a new tool to estimate all nuclear reaction rates of relevance to astrophysics with improved accuracy and reliability. (authors)

  9. Out-of-equilibrium phenomena in high energy nuclear collisions

    CERN Document Server

    Serreau, J

    2001-01-01

    In the first part we study the possibility that a Disoriented Chiral Condensate (DCC) forms when hot hadronic matter is quenched, using the linear sigma model. We formulate an original sampling strategy for the initial field configuration in order to get an estimate of the probability that a potentially observable coherent pion field appears in a heavy-ion collision. We obtain a probability of the order of 1/1000 at CERN SPS energies. Next, we study the correlation between isospin orientations of the distinct modes of the pion field emerging after a quench. We show that this correlation is absent: the distinct modes behave as distinct DCCs. This contradicts the common belief that the state produced in the simplest form of the quench scenario - with a fully thermalized initial state - is identical to the originally proposed DCC. In the second part, we investigate the role of elastic scatterings in the process of kinetic equilibration of gluons produced in the very early times of the collision. We compare the t...

  10. FONLL calculations for heavy quark production in nuclear collisions

    CERN Document Server

    Niel, Elisabeth Maria

    2017-01-01

    The ALICE detector at the LHC has been designed to study the collisions of heavy nuclei at energies much higher then the previous dedicated experiments at the Relativistic Heavy-Ion Collider (RHIC) of the Brookhaven National Laboratory. Colliding heavy nuclei allows to reproduce the hot and dense plasma of quarks and gluons (QGP) existing right after the Big Bang and hence study the very first instants of universe’s existence. In heavy ions collisions, heavy flavours, such as beauty and charm quark, are fundamental probes for the quark gluon plasma properties. That is because they experience the entire evolution of the system since they are produced at the very beginning. They are indeed a very powerful tool to test field theories such as Quantum Chromodynamics (QCD). Theoretical models predict that a fast parton(quark or gluon) looses energy while traversing a medium composed of colour charges. This phenomenon is called "jet quenching", it can be used to describe the QGP. It was first observed at RHIC by m...

  11. A study of vorticity formation in high energy nuclear collisions

    Energy Technology Data Exchange (ETDEWEB)

    Becattini, F. [Universita di Firenze, Dipartimento di Fisica e Astronomia, Sesto F.no (Firenze) (Italy); INFN, Sezione di Firenze, Sesto F.no (Firenze) (Italy); Inghirami, G. [Universita di Firenze, Dipartimento di Fisica e Astronomia, Sesto F.no (Firenze) (Italy); Johann Wolfgang Goethe University, Frankfurt Institute for Advanced Studies (FIAS), Frankfurt am Main (Germany); Rolando, V.; Pagliara, G. [Universita di Ferrara, Dipartimento di Fisica e Scienze della Terra, Ferrara (Italy); INFN, Sezione di Ferrara, Ferrara (Italy); Beraudo, A.; De Pace, A.; Nardi, M. [INFN, Sezione di Torino, Turin (Italy); Del Zanna, L. [Universita di Firenze, Dipartimento di Fisica e Astronomia, Sesto F.no (Firenze) (Italy); INFN, Sezione di Firenze, Sesto F.no (Firenze) (Italy); INAF, Osservatorio Astrofisico di Arcetri, Florence (Italy); Chandra, V. [Indian Institute of Technology Gandhinagar, Ahmedabad, Gujrat (India)

    2015-09-15

    We present a quantitative study of vorticity formation in peripheral ultrarelativistic heavy-ion collisions at √(s{sub NN}) = 200 GeV by using the ECHO-QGP numerical code, implementing relativistic dissipative hydrodynamics in the causal Israel-Stewart framework in 3 + 1 dimensions with an initial Bjorken flow profile. We consider different definitions of vorticity which are relevant in relativistic hydrodynamics. After demonstrating the excellent capabilities of our code, which proves to be able to reproduce Gubser flow up to 8 fm/c, we show that, with the initial conditions needed to reproduce the measured directed flow in peripheral collisions corresponding to an average impact parameter b = 11.6 fm and with the Bjorken flow profile for a viscous Quark Gluon Plasma with η/s = 0.1 fixed, a vorticity of the order of some 10{sup -2} c/fm can develop at freeze-out. The ensuing polarization of Λ baryons does not exceed 1.4 % at midrapidity. We show that the amount of developed directed flow is sensitive to both the initial angular momentum of the plasma and its viscosity. (orig.)

  12. [Electromagnetic studies of nuclear structure and reactions

    International Nuclear Information System (INIS)

    1991-01-01

    The past year has seen continued progress in our efforts. On the experimental side, we completed data acquisition on our major remaining involvement at NIKHEF, the 12 C(e,e'pp) experiment. We advanced the analysis of most of projects in low lying nuclear structure and giant resonances, of which several were completed and published. We received approval for several new experiments, and have made major contributions to design and development of detectors to be used at Bates and CEBAF. Our data interpretation efforts have been extended and enhanced with the availability of our new computer cluster. In this paper we briefly report on most of these efforts

  13. Search for dibaryonic de-excitations in relativistic nuclear reactions

    International Nuclear Information System (INIS)

    Besliu, C.; Popa, V.; Popa, L.; Topor Pop, V.

    1993-08-01

    Some odd characteristics are observed in the single particle distributions obtained from He + Li interactions at 4.5AGeV/c momenta which are explained as the manifestation of a new mechanism of strangeness production via dibaryonic de-excitations. A signature of the formation of hadronic and baryonic clusters is also reported. The di- pionic signals of the dibaryonic orbital de- excitations are analyzed in the frame of the MIT -bag Model and a Monte Carlo simulation. The role played by the dibaryonic resonances in relativistic nuclear collisions could be a significant one. (author). 29 refs, 7 figs

  14. Search for dibaryonic de-excitations in relativistic nuclear reactions

    International Nuclear Information System (INIS)

    Besliu, C.; Popa, V.; Popa, L.; Topor Pop, V.

    1992-08-01

    Some old characteristics are observed in the single particle distributions obtained from He + Li interactions at 4.5 A GeV/c momenta, which are explained as the manifestation of a few mechanism of strangeness production via dibaryonic de-excitations. A signature of formation of hadronic and baryonic clusters is also reported. The di-pionic signals of the dibaryonic orbital de-excitations are analysed in the frame of the MIT-bag model and the Monte Carlo simulation. The role played by the dibaryonic resonances in the relativistic nuclear collisions could be a significant one. (author). 23 refs, 5 figs, 1 tab

  15. Nuclear reactions: public attitudes and policies toward nuclear power

    International Nuclear Information System (INIS)

    Freudenburg, W.R.; Baxter, R.K.

    1985-01-01

    The declining public support for nuclear power has political costs. In the wake of the Three Mile Island accident, public trust in the nuclear industry has reached an all-time low. Recognition of this lack of trust sets up a counterweight to the industry pressures for relaxed regulation. The authors present the historical background behind the current debate, then summarize the available scientific survey data on the actual levels and trends in public attitudes. They find little reason for optimism. With the exception of gender, most demographic factors have only modest influence on nuclear power attitudes, which suggests that public uneasiness about the technology has become a fact of life. They conclude that a significant weakening of federal safety standards would not be consistent with public preferences. 49 references, 3 figures

  16. Nuclear reaction analysis of hydrogen in materials: Principals and applications

    International Nuclear Information System (INIS)

    Lanford, W.A.

    1991-01-01

    Analysis for hydrogen in materials is difficult by most traditional analytic methods. Because hydrogen has no Auger transitions, no X-ray transitions, does not neutron activate, and does not backscatter ions, it is invisible in analytical methods based on these effects. In addition, since hydrogen is a universal contaminant in vacuum systems, techniques based on mass spectrometry are difficult unless extreme measures are taken to reduce hydrogen backgrounds. Because of this situation, methods have been developed for analyzing for hydrogen in solid materials based on nuclear reactions between bombarding ions and hydrogen atoms (protons) in the samples. The nuclear reaction methods are now practiced at laboratories around the world. The basic principals of nuclear reaction analysis will be briefly presented. This method will be illustrated by applications to problems ranging from basic physics, to geology, to materials science, and to art history and archeology

  17. Nuclear transfer in peripheral heavy ion reactions

    International Nuclear Information System (INIS)

    Werner, K.

    1984-01-01

    The aim of the whole thesis is to understand the experimental results of N. Frascaria et al. (1980), namely structures in the cross section as function of the excitation energy for the reaction 40 Ca + 40 Ca at 400 MeV incident energy. We present therefore in chapter 1 a simple model of two identical potentials with only two energy levels. On the base of statistically independent T-L excitations and by fitting a two parameters to the experiments it succeeds to reproduce sufficiently the experimental results. The next step is a microscopical treatment of these parameters for the understanding and the foundation of the fitted values. For this we develop in chapter 2 a theory of collective variables in the framework of TDHF which allows to perform in chapter 3 in a very transparent way microscopical calculations and especially to understand the transfer behaviour in peripheral heavy ion reactions. This transfer behaviour will also be the key for the understanding of the experimental structures. (orig.) [de

  18. Nuclear modification factor for J/ψ production in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Xu Xiaoming; Zhou Jie

    2011-01-01

    The STAR Collaboration has offered an eminent nuclear modification factor of J/ψ at high p T and midrapidity produced in Cu-Cu collisions at √ s NN= 200 GeV. Recalling a prediction, we can understand that the feature of high-p T nuclear modification factor is related to cc produced by 2 → 1 and 2 → 2 partonic processes in deconfined matter, particularly in the prethermal stage and to the recombination of c and c-bar. The nuclear modification factor at high p T is sensitive to the earliest form of deconfined matter that does not have a temperature.(authors)

  19. Constraining the EOS of Neutron-Rich Nuclear Matter and Properties of Neutron Stars with Heavy-Ion Reactions

    International Nuclear Information System (INIS)

    Li Baoan; Worley, Aaron; Chen, L.-W.; Ko, Che Ming; Krastev, Plamen G.; Wen Dehua; Xiao Zhigang; Zhang Ming; Xu Jun; Yong Gaochan

    2009-01-01

    Heavy-ion reactions especially those induced by radioactive beams provide useful information about the density dependence of the nuclear symmetry energy, thus the Equation of State of neutron-rich nuclear matter, relevant for many astrophysical studies. The latest developments in constraining the symmetry energy at both sub- and supra-saturation densities from analyses of the isopsin diffusion and the π - /π + ratio in heavy-ion collisions using the IBUU04 transport model are discussed. Astrophysical ramifications of the partially constrained symmetry energy on properties of neutron star crusts, gravitational waves emitted by deformed pulsars and the w-mode oscillations of neutron stars are presented briefly.

  20. Role amplification of the coulomb interaction in nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

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

    1976-10-01

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

  1. Intermediate behaviour of reaction mechanisms in 27Al + 63Cu collisions at 13.4 MeV/nucleon

    International Nuclear Information System (INIS)

    Bougault, R.

    1983-09-01

    This experiment aimed to investigate the nuclear reaction mechanisms in the energy transition region between 10 and 20 MeV/Nucleon. So, collisions between 27 Al (projectile) and 63 Cu (target) were studied for a bombarding energy of 13.4 MeV/nucleon. For that purpose, projectile-like fragments were detected at the grazing angle (thetasub(g)) for that system by a spectrometer and an E-ΔE telescope. A second telescope was set at various angles for light particle detection; both inclusive and coincident measurements were performed. Isotope production at angle thetasub(g) cannot be clearly explained neither by inelastic transfers nor by ''cold'' projectile fragmentation. This production seems rather to occur through an intermediate process where the Al nucleus is slowed down, and excited, and then dissociates. Moreover, kinematical correlations between fragments show evidence for a mechanism where the projectile is splitted after picking up some nucleons to the target. Finally, light particles are shown to araise essentially from a fusion-like system thermalized at T=3,5 MeV; such a temperature may be considered as an intermediate value [fr

  2. Quantitative surface analysis using deuteron-induced nuclear reactions

    International Nuclear Information System (INIS)

    Afarideh, Hossein

    1991-01-01

    The nuclear reaction analysis (NRA) technique consists of looking at the energies of the reaction products which uniquely define the particular elements present in the sample and it analysis the yield/energy distribution to reveal depth profiles. A summary of the basic features of the nuclear reaction analysis technique is given, in particular emphasis is placed on quantitative light element determination using (d,p) and (d,alpha) reactions. The experimental apparatus is also described. Finally a set of (d,p) spectra for the elements Z=3 to Z=17 using 2 MeV incident deutrons is included together with example of more applications of the (d,alpha) spectra. (author)

  3. A study on the hierarchy model of nuclear reactions

    International Nuclear Information System (INIS)

    Kitazoe, Yasuhiro; Sekiya, Tamotsu

    1975-01-01

    The application of the hierarchy model of nuclear reaction is discussed, and the hierarchy model means that the compound nucleus state is formed after several steps, at least, one step of reaction. This model was applied to the analysis of the observed cross sections of 235 U and some other elements. Neglecting exchange scattering effect, the equations for the total neutron cross section of 235 U were obtained. One of these equations describes explicitly the hierarchy of the transition from intermediate reaction state Xm into the compound nucleus state Xs, and another one describes the cross section averaged over an energy interval larger than the average level spacing of compound nucleus eigenvalues. The hierarchy of reaction mechanism was investigated in more detail, and the hierarchy model was applied to the case of unresolved energy region. It was not tried to evaluate the strength function in the mass region (A>140), since the effect of nuclear deformation was neglected in the task. (Iwase, T.)

  4. Peripheral collisions in the reaction 40Ar + 93Nb at 27.5 MeV/nucleon

    International Nuclear Information System (INIS)

    Pastel, R.

    1987-09-01

    This thesis describes an experimental study of the reaction 40 Ar + 93 Nb at 27.5 MeV/nucleon carried out at the GANIL accelerator. Reaction products were detected in a large position sensitive localization ionization chamber. The experimental data were used to obtain information concerning the reaction mechanism especially for peripheral collisions. A model using the properties of random works were applied successfully to the interpretation of the data. The importance of the deflection produced by the ion-ion potential as well as of the emission of alpha particles in the reaction is stressed [fr

  5. Probing properties of neutron stars with terrestrial nuclear reactions

    International Nuclear Information System (INIS)

    Li Baoan; Chen Liewen; Ko, C.M.; Steiner, Andrew W.; Yong Gaochan

    2006-01-01

    Heavy-ion reactions induced by neutron-rich nuclei provide the unique opportunity in terrestrial laboratories to constrain the nuclear symmetry energy Esym in a broad density range. A conservative constraint, 32(ρ/ρ0)0.7 < Esym(ρ) < 32(ρ/ρ0)1.1, around the nuclear matter saturation density ρ0 has recently been obtained from analyzing the isospin diffusion data within a transport model for intermediate energy heavy-ion reactions. This subsequently puts a stringent constraint on properties of neutron stars, especially their radii and cooling mechanisms

  6. Statistical methods of spin assignment in compound nuclear reactions

    International Nuclear Information System (INIS)

    Mach, H.; Johns, M.W.

    1984-01-01

    Spin assignment to nuclear levels can be obtained from standard in-beam gamma-ray spectroscopy techniques and in the case of compound nuclear reactions can be complemented by statistical methods. These are based on a correlation pattern between level spin and gamma-ray intensities feeding low-lying levels. Three types of intensity and level spin correlations are found suitable for spin assignment: shapes of the excitation functions, ratio of intensity at two beam energies or populated in two different reactions, and feeding distributions. Various empirical attempts are examined and the range of applicability of these methods as well as the limitations associated with them are given. 12 references

  7. Statistical methods of spin assignment in compound nuclear reactions

    International Nuclear Information System (INIS)

    Mach, H.; Johns, M.W.

    1985-01-01

    Spin assignment to nuclear levels can be obtained from standard in-beam gamma-ray spectroscopy techniques and in the case of compound nuclear reactions can be complemented by statistical methods. These are based on a correlation pattern between level spin and gamma-ray intensities feeding low-lying levels. Three types of intensity and level spin correlations are found suitable for spin assignment: shapes of the excitation functions, ratio of intensity at two beam energies or populated in two different reactions, and feeding distributions. Various empirical attempts are examined and the range of applicability of these methods as well as the limitations associated with them are given

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

    International Nuclear Information System (INIS)

    Ohbayasi, Yosihide; Masui, Hiroshi; Aoyama, Shigeyoshi; Kato, Kiyoshi; Chiba, Masaki

    2000-01-01

    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)

  9. EXFOR Systems Manual Nuclear reaction Data Exchange Format

    International Nuclear Information System (INIS)

    McLane, V.

    2000-01-01

    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

  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. US nuclear reaction data program in support of basic research

    International Nuclear Information System (INIS)

    Bhat, M.R.; Chadwick, M.B.; Smith, M.S.

    1997-01-01

    Information about the US Nuclear Reaction Data Network (USNRDN) such as its members, work in progress, summaries of meetings, and organizational details may be found in its WWW Homepage. This paper is an overview of the data support provided by the network for basic research in nuclear astrophysics, radioactive ion beams, high energy heavy-ion and electron interactions and related activities involving all aspects of data stewardship

  12. Review of nuclear reaction data evaluation in the US

    Energy Technology Data Exchange (ETDEWEB)

    Howerton, R.J.

    1985-05-01

    The development of the nuclear reaction data evaluation activities in the US over the last 40 years is reviewed, starting with comments on several reports as early as 1944. The review moves on to the development of consortia to share the burden by interchanging sets of data and efforts toward putting together an encoding system and computer-oriented formats. It is predicted that future emphasis is likely to be on charged particle induced reactions. (LEW)

  13. Exclusive nuclear reactions: Can you count on the deuteron?

    International Nuclear Information System (INIS)

    Holt, R.J.

    1991-01-01

    Three of the simplest nuclear reactions -- (1) electron-deuteron elastic scattering, (2) electro-disintegration of the deuteron near threshold and at high momentum transfer, and (3) photodisintegration of the deuteron at high energy -- were believed to have unique signatures for OCD effects in nuclei. The progress in the past few years with regard to these reactions will be traced and the results will be compared with recent theoretical predictions. 36 refs., 12 figs., 1 tab

  14. 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.

  15. Review of nuclear reaction data evaluation in the US

    International Nuclear Information System (INIS)

    Howerton, R.J.

    1985-05-01

    The development of the nuclear reaction data evaluation activities in the US over the last 40 years is reviewed, starting with comments on several reports as early as 1944. The review moves on to the development of consortia to share the burden by interchanging sets of data and efforts toward putting together an encoding system and computer-oriented formats. It is predicted that future emphasis is likely to be on charged particle induced reactions

  16. Concrete alkali-silica reaction and nuclear radiation damage

    International Nuclear Information System (INIS)

    Ichikawa, Tsuneki

    2008-01-01

    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 Ca 2+ ions into the solution. The alkali silicate surrounding the aggregates then reacts with Ca 2+ 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 10 8 Gy, which suggests that the ASR of concrete surrounding nuclear reactors is possible to be accelerated by nuclear radiation. (author)

  17. Heavy ion collision dynamics of 10,11B+10,11B reactions

    Directory of Open Access Journals (Sweden)

    Singh BirBikram

    2015-01-01

    Full Text Available The dynamical cluster-decay model (DCM of Gupta and collaborators has been applied successfully to the decay of very-light (A ∼ 30, light (A ∼ 40−80, medium, heavy and super-heavy mass compound nuclei for their decay to light particles (evaporation residues, ER, fusion-fission (ff, and quasi-fission (qf depending on the reaction conditions. We intend to extend here the application of DCM to study the extreme case of decay of very-light nuclear systems 20,21,22Ne∗ formed in 10,11B+10,11B reactions, for which experimental data is available for their binary symmetric decay (BSD cross sections, i.e., σBSD. For the systems under study, the calculations are presented for the σBSD in terms of their preformation and barrier penetration probabilities P0 and P. Interesting results are that in the decay of such lighter systems there is a competing reaction mechanism (specifically, the deep inelastic orbiting of non-compound nucleus (nCN origin together with ff. We have emipirically estimated the contribution of σnCN. Moreover, the important role of nuclear structure characteristics via P0 as well as angular momentum ℓ in the reaction dynamics are explored in the study.

  18. Statistical calculation of complete events in medium-energy nuclear collisions

    International Nuclear Information System (INIS)

    Randrup, J.

    1984-01-01

    Several heavy-ion accelerators throughout the world are presently able to deliver beams of heavy nuclei with kinetic energies in the range from tens to hundreds of MeV per nucleon, the so-called medium or intermediate energy range. At such energies a large number of final channels are open, each consisting of many nuclear fragments. The disassembly of the collision system is expected to be a very complicated process and a detailed dynamical description is beyond their present capability. However, by virtue of the complexity of the process, statistical considerations may be useful. A statistical description of the disassembly yields the least biased expectations about the outcome of a collision process and provides a meaningful reference against which more specific dynamical models, as well as the data, can be discussed. This lecture presents the essential tools for formulating a statistical model for the nuclear disassembly process. The authors consider the quick disassembly (explosion) of a hot nuclear system, a so-called source, into multifragment final states, which complete according to their statistical weight. First some useful notation is introduced. Then the expressions for exclusive and inclusive distributions are given and the factorization of an exclusive distribution into inclusive ones is carried out. In turn, the grand canonical approximation for one-fragment inclusive distributions is introduced. Finally, it is outlined how to generate a statistical sample of complete final states. On this basis, a model for statistical simulation of complete events in medium-energy nuclear collisions has been developed

  19. 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.

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

    International Nuclear Information System (INIS)

    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

  1. [Research in heavy ion nuclear reactions

    International Nuclear Information System (INIS)

    Howell, E.H.; Liu, X.T.; Petitt, G.A.; Zhang, Z.

    1994-01-01

    The authors have been involved in several projects during the present contract period. These include participation in the RD93 test run performed last summer at the Alternating Gradient Synchrotron (AGS) at Brookhaven, analysis of the data from this run, Monte Carlo simulations using the GEANT code of the performance of the calorimeter/absorber used in RD45, and simulations of the performance of the muon detector system for the PHENIX detector at RHIC using the PISA code. They have been preparing for tests to be performed this summer at the AGS of a prototype muon identifier using limited streamer tube detectors of the type selected for use in the muon arm of the PHENIX detector at RHIC. They have begun work on Monte Carlo simulations of particle detection in the presence of intense background events for the E864 experiment which is approved for running at the AGS. Finally, the authors have completed their work on leakage from the absorber/calorimeter and have submitted a paper to Nuclear Instruments and Methods

  2. Variational methods for chemical and nuclear reactions

    International Nuclear Information System (INIS)

    Crawford, O.H.

    1977-01-01

    All the variational functionals are derived which satisfy certain criteria of suitability for molecular and nuclear scattering, below the threshold energy for three-body breakup. The existence and uniqueness of solutions are proven. The most general suitable functional is specialized, by particular values of its parameters, to Kohn's taneta, Kato's cot(eta-theta), the inverse Kohn coeta, Kohn's S matrix, our S matrix, Lane and Robson's functional, and several new functionals, an infinite number of which are contained in the general expression. Four general ways of deriving algebraic methods from a given functional are discussed, and illustrated with specific algebraic results. These include equations of Lane and Robson and of Kohn, the fundamental R matrix relation, and new equations. The relative configuration space is divided as in the Wigner R matrix theory, and trial wavefunctions are needed for only the region where all the particles are interacting. In addition, a version of the general functional is presented which does not require any division of space

  3. Hadronic energy spectra from nuclear collisions: Effects from collective transverse flow and the phase transition to quark matter

    International Nuclear Information System (INIS)

    Heinz, U.

    1988-11-01

    I give an overview of the processes determining the shape of energy spectra of hadrons emitted in relativistic nuclear collisions, and discuss how one can extract from them information on the presence of collective transverse flow and on the transition to quark-gluon matter in such collisions. 6 refs., 3 figs

  4. Nuclear reaction rates and primordial 6Li

    International Nuclear Information System (INIS)

    Nollett, K.M.; Schramm, D.N.; Lemoine, M.; Schramm, D.N.; Lemoine, M.; Schramm, D.N.

    1997-01-01

    We examine the possibility that big-bang nucleosynthesis (BBN) may produce nontrivial amounts of 6 Li. If a primordial component of this isotope could be observed, it would provide a new fundamental test of big-bang cosmology, as well as new constraints on the baryon density of the universe. At present, however, theoretical predictions of the primordial 6 Li abundance are extremely uncertain due to difficulties in both theoretical estimates and experimental determinations of the 2 H(α,γ) 6 Li radiative capture reaction cross section. We also argue that present observational capabilities do not yet allow the detection of primeval 6 Li in very metal-poor stars of the galactic halo. However, if the critical cross section is very high in its plausible range and the baryon density is relatively low, then improvements in 6 Li detection capabilities may allow the establishment of 6 Li as another product of BBN. It is also noted that a primordial 6 Li detection could help resolve current concerns about the extragalactic D/H determination. copyright 1997 The American Physical Society

  5. arXiv Isothermal compressibility of hadronic matter formed in relativistic nuclear collisions

    CERN Document Server

    Mukherjee, Maitreyee; Chatterjee, Arghya; Chatterjee, Sandeep; Adhya, Souvik Priyam; Thakur, Sanchari; Nayak, Tapan K.

    We present the first estimates of isothermal compressibility (\\kT) of hadronic matter formed in relativistic nuclear collisions (\\sNN=7.7~GeV to 2.76~TeV) using experimentally observed quantities. \\kT~is related to the fluctuation in particle multiplicity, temperature and volume of the system formed in the collisions. Multiplicity fluctuations are obtained from the event-by-event distributions of charged particle multiplicities in narrow centrality bins. The dynamical components of the fluctuations are extracted by removing the contributions to the fluctuations from the number of participating nucleons. From the available experimental data, a constant value of \\kT~has been observed as a function of collision energy. The results are compared with calculations from UrQMD, AMPT and EPOS event generators, and estimations of \\kT~are made for Pb-Pb collisions at the CERN Large Hadron Collider. A hadron resonance gas (HRG) model has been used to calculate \\kT~as a function of collision energy. Our results show a dec...

  6. Is the relativistic approach really useful to nuclear reactions?

    CERN Document Server

    Miyazaki, K

    2003-01-01

    We have reconsidered the non-relativistic distorted-wave t-matrix approximation (NR-DWTA) for proton knockout (p,2p) reaction using modern high-quality phenomenological optical potentials and NN t-matrix. We have calculated 40Ca(p,2p) reactions at T_LAB=200MeV and compared the results with the relativistic distorted-wave impulse approximation (RDWIA) calculations. It is found that the NR-DWTA is superior to the RDWIA in consistent description of the cross section and the analyzing power. An immediate relativistic extension of the DWIA to the nuclear reaction has a problem.

  7. Semi-similar properties of light nuclear collisions

    International Nuclear Information System (INIS)

    Glagolev, V.V.; Hlavakova, J.; Martinska, G.; Urban, J.; Vytykacova, M.

    2000-01-01

    A new way of the representation of the nuclei fragmentation data is suggested. The self-similar behaviour of these processes called out by the kinematics is demonstrated. The convenience of working in accelerated nuclei is emphasized particularly for the determination of the binding energy of a wide class of nuclear fragments [ru

  8. Theory of nuclear reactions, with applications to heavy ion scattering reactions

    International Nuclear Information System (INIS)

    Youssef, M.S.A.

    1981-01-01

    Nuclear science to day, has gained its stature through the pioneer work of both theorists and experimentalists within its two main divisions, Nuclear Reaction and Nuclear Structure theories. Our main interest in this theoretical work in nuclear reaction theory is focused on three topics, come under the headings of three parts which are the constituents of the present paper. Part 1 is concerned with ''Contributions to the theory of Threshold phenomena in nuclear reactions; cluster threshold states in heavy ion reactions''. Part II is devoted to ''Hermiticity of the Laplacian operator, R-matrix theories and direct interaction theory'', while part xII is ascribed to ''Heavy ion transfer reactions and scattering''. The aforementioned selected topics are the backbones of this thesis, which starts with general introduction giving a brief account about the material included in. In each part, investiqations are given in an extended manner through several chapters. Finally, the thesis is ended eith the chapter on ''General Discussions and Conclusions''. Appendices, references, and figure captions are found at the end of each part, the matter which we believe to facilitate much the reading through of the thesis. The first two parts are based (to some extent) on the same formal background (R-matrix, Kapur-Peierls-theories) and they converge to solve some physical problems originating from flux conservation laws in nuclear reactions, while the third part is indirect related to the first two; in principle it joins the other two parts under computational aspects. All of them after all, form the solidarity of the material included in the thesis. (author)

  9. In search of high density collective phenomena in nuclear collision

    International Nuclear Information System (INIS)

    Gyulassy, M.

    1979-06-01

    The progress made toward uncovering signatures of collective phenomena is reviewed. Elements of the basic reaction mechanism leading to a complex background are first discussed. Possible hints of collective phenomena in proton and pion single and double inclusive spectra as well as π - multiplicity data are then described. 6 figures, 2 tables

  10. Improved predictions of nuclear reaction rates for astrophysics applications with the TALYS reaction code

    International Nuclear Information System (INIS)

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

    2008-01-01

    Nuclear reaction rates for astrophysics applications are traditionally determined on the basis of Hauser-Feshbach reaction codes, like MOST. These codes use simplified schemes to calculate the capture reaction cross section on a given target nucleus, not only in its ground state but also on the different thermally populated states of the stellar plasma at a given temperature. Such schemes include a number of approximations that have never been tested, such as an approximate width fluctuation correction, the neglect of delayed particle emission during the electromagnetic decay cascade or the absence of the pre-equilibrium contribution at increasing incident energies. New developments have been brought to the reaction code TALYS to estimate the Maxwellian-averaged reaction rates of astrophysics relevance. These new developments give us the possibility to calculate with an improved accuracy the reaction cross sections and the corresponding astrophysics rates. The TALYS predictions for the thermonuclear rates of astrophysics relevance are presented and compared with those obtained with the MOST code on the basis of the same nuclear ingredients for nuclear structure properties, optical model potential, nuclear level densities and γ-ray strength. It is shown that, in particular, the pre-equilibrium process significantly influences the astrophysics rates of exotic neutron-rich nuclei. The reciprocity theorem traditionally used in astrophysics to determine photo-rates is also shown no to be valid for exotic nuclei. The predictions obtained with different nuclear inputs are also analyzed to provide an estimate of the theoretical uncertainties still affecting the reaction rate prediction far away from the experimentally known regions. (authors)

  11. 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.

  12. Public reactions to nuclear waste: Citizens' views of repository siting

    International Nuclear Information System (INIS)

    Rosa, E.A.

    1993-01-01

    This book presents revised and updated papers from a panel of social scientists, at the 1989 AAAS meetings, that examined the public's reactions to nuclear waste disposal and the repository siting process. The papers report the results of original empirical research on citizens' views of nuclear waste repository siting. Topics covered include the following: content analysis of public testimony; sources of public concern about nuclear waste disposal in Texas agricultural communities; local attitudes toward high-level waste repository at Hanford; perceived risk and attitudes toward nuclear wastes; attitudes of Nevada urban residents toward a nuclear waste repository; attitudes of rural community residents toward a nuclear waste respository. An introductory chapter provides background and context, and a concluding chapter summarizes the implications of the reports. Two additional chapters cover important features of high-level waste disposal: long term trends in public attitudes toward nuclear energy and nuclear waste policy and assessment of the effects on the Los Vegas convention business if a high-level nuclear waste depository were sited in Nevada

  13. Exploratory study of nuclear reaction data utility framework of Japan charged particle reaction data group (JCPRG)

    International Nuclear Information System (INIS)

    Masui, Hiroshi; Ohnishi, Akira; Kato, Kiyoshi; Ohbayasi, Yosihide; Aoyama, Shigeyoshi; Chiba, Masaki

    2002-01-01

    Compilation, evaluation and dissemination are essential pieces of work for the nuclear data activities. We, Japan charged particle data group, have researched the utility framework for the nuclear reaction data on the basis of recent progress of computer and network technologies. These technologies will be not only for the data dissemination but for the compilation and evaluation assistance among the many corresponding researchers of all over the world. In this paper, current progress of our research and development is shown. (author)

  14. The role of nuclear reaction theory and data in nuclear energy and safety applications

    International Nuclear Information System (INIS)

    Schmidt, J.J.

    1993-01-01

    The nuclear data requirements for nuclear fission reactor design and safety computations are so large that they cannot be satisfied by experimental measurements alone. Nuclear reaction theories and models have recently been developed and refined to the extent, that, with suitable parametrisation and fitting to accurately known experimental data, they can be used for filling gaps in the available experimental nuclear data base as well as for bulk computations of nuclear reaction, e.g. activation cross sections. The concurrent rapid development of ever more powerful mainframe and personal computers has stimulated the development of comprehensive nuclear model computer codes. A representative selection of such codes will be presented in the lectures and computer exercises of this Workshop. In order to fulfill nuclear data requirements of the nineties and, at the same time, develop improved tools for nuclear physics teaching at developing country universities it will be required and a major future task of the IAEA nuclear data programme to develop computer files of ''best'' sets of nuclear parameters for standardised input to nuclear model computations of nuclear data. Nuclear scientists from developing countries can make substantial contributions to this project. (author). 25 refs

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

    International Nuclear Information System (INIS)

    Numajiri, Masaharu; Miura, Taichi; Oki, Yuichi

    1994-01-01

    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)

  16. 'Level-level correlation and absorption in nuclear reactions'

    International Nuclear Information System (INIS)

    Hussein, M.S.

    Level-level correlation (LLC) in nuclear reactions is discussed in general and it is shown that in the presence of LLC, N sub(μ) = Σ/g μa/ 2 > divided by gamma μ T tilde, where T tilde is the average absorption in the eigen channels [pt

  17. Nuclear momentum distribution and relativistic heavy-ion reactions

    International Nuclear Information System (INIS)

    Wong, C.Y.; Blankenbecler, R.

    1980-01-01

    In terms of a direct fragmentation process and a hard-scattering process, the proton-inclusive data for the reaction α + 12 C → p + X have been successfully analyzed. The extracted semiempirical momentum distribution indicates possible evidence of nuclear correlations and final-state interactions. 4 figures

  18. N-body methods in the theory of nuclear reactions

    International Nuclear Information System (INIS)

    Bencze, Gy.

    1980-08-01

    The traditional method of applying two-body methods for the study of nuclear reactions is briefly reviewed. The recent developments in the N particle scattering theory are described in detail. The application of the methods in the study of effective two and few-body problems is also considered. (P.L.)

  19. Testing nuclear parton distributions with pA collisions at the LHC

    CERN Document Server

    Quiroga-Arias, Paloma; Wiedemann, Urs Achim

    2010-01-01

    Global perturbative QCD analyses, based on large data sets from electron-proton and hadron collider experiments, provide tight constraints on the parton distribution function (PDF) in the proton. The extension of these analyses to nuclear parton distributions (nPDF) has attracted much interest in recent years. nPDFs are needed as benchmarks for the characterization of hot QCD matter in nucleus-nucleus collisions, and attract further interest since they may show novel signatures of non-linear density-dependent QCD evolution. However, it is not known from first principles whether the factorization of long-range phenomena into process-independent parton distribution, which underlies global PDF extractions for the proton, extends to nuclear effects. As a consequence, assessing the reliability of nPDFs for benchmark calculations goes beyond testing the numerical accuracy of their extraction and requires phenomenological tests of the factorization assumption. Here we argue that a proton-nucleus collision program at...

  20. Testing collinear factorization and nuclear parton distributions with pA collisions at the LHC

    CERN Document Server

    Quiroga-Arias, Paloma; Wiedemann, Urs Achim

    2011-01-01

    Global perturbative QCD analyses, based on large data sets from electron-proton and hadron collider experiments, provide tight constraints on the parton distribution function (PDF) in the proton. The extension of these analyses to nuclear parton distributions (nPDF) has attracted much interest in recent years. nPDFs are needed as benchmarks for the characterization of hot QCD matter in nucleus-nucleus collisions, and attract further interest since they may show novel signatures of non- linear density-dependent QCD evolution. However, it is not known from first principles whether the factorization of long-range phenomena into process-independent parton distribution, which underlies global PDF extractions for the proton, extends to nuclear effects. As a consequence, assessing the reliability of nPDFs for benchmark calculations goes beyond testing the numerical accuracy of their extraction and requires phenomenological tests of the factorization assumption. Here we argue that a proton-nucleus collision program a...

  1. The nuclear response and the imaginary potential for nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Phatak, S.C.; Sinha, B.

    1983-01-01

    The Fermi-gas model is used in this paper to study the nucleus-nucleus collision. The field produced by one of the nuclei is considered to act on nucleons in the other nucleus, which is treated as a Fermi gas of radius R. The imaginary part of the (non-local) nucleus-nucleus potential is then computed by evaluating the energy-conserving second-order term in which the intermediate states are particle-hole excitations produced in the Fermi gas. The equivalent local potential, obtained by using the Perey-Saxon method, is compared with phenomenological imaginary potentials. Later it is shown that, in the limit of small range of non-locality, the imaginary potential can be related to the nuclear response function. With this, one can write the nuclear friction coefficient that is used in phenomenological analyses of heavy-ion collisions in terms of the imaginary potential. (orig.)

  2. Dynamic screening in solar and stellar nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Daeppen, W. [Department of Physics and Astronomy, University of Southern California, Los Angeles, CA (United States); Mussack, K. [Los Alamos National Laboratory, XTD-2, Los Alamos, NM (United States)

    2012-02-15

    In the hot, dense plasma of solar and stellar interiors, Coulomb potentials are screened, resulting in increased nuclear reaction rates. Although Salpeter's approximation for static screening is widely accepted and used in stellar modeling, the question of screening in nuclear reactions was revisited in the 1990s. In particular the issue of dynamic effects was raised by Shaviv and Shaviv, who applied the techniques of molecular dynamics to the conditions in the Sun's core in order to numerically determine the effect of screening. By directly calculating the motion of ions and electrons due to Coulomb interactions, the simulations are used to compute the effect of screening without the mean-field assumption inherent in Salpeter's approximation. In the last few years, the USC group has first reproduced Shaviv and Shaviv's numerical analysis of the screening energy, showing an effect of dynamic screening. When the consequence for the reaction-rate was computed, a rather surprising resulted, which is contrary to that from static screening theory. Our calculations showed that dynamic screening does not significantly change the reaction rate from that of the bare Coulomb potential. If this can be independently confirmed, then the effects of dynamic screening are highly relevant and should be included in stellar nuclear reaction rates (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Evidence for two different reaction mechanisms in heavy ion collisions in the GeV/nucl. region

    International Nuclear Information System (INIS)

    Baumgardt, H.G.; Friedlaender, E.; Schopper, E.

    1981-01-01

    It is the aim of this paper to show up evidence for two different types of interactions in N-N collisions which are mutually excluding each other. The complexity of N-N interactions and dissipation effects make it difficult to disentangle signatures for collective mechanisms from the observable data of the final state of the reaction. Hence rough separation into different types of collisions - central or peripheral - has often been attempted, for instance by means of the multiplity of target and/or projectile fragments. (orig.)

  4. [Research in theoretical nuclear physics

    International Nuclear Information System (INIS)

    1993-01-01

    Research in progress and plans for future investigations are briefly summarized for the following areas: light-ion structure and reactions; nuclear structure; peripheral heavy-ion reactions at medium and high energy; medium-energy heavy-ion collisions and properties of highly excited nuclear matter; and high-energy heavy-ion collisions and QCD plasma

  5. Some comments on the behaviour of the excited nuclear matter formed in nuclear collisions at high energies

    International Nuclear Information System (INIS)

    Besliu, Calin; Jipa, Alexandru; Argintaru, Dan

    2003-01-01

    In the last years many experiments have been performed in different laboratories to investigate the behaviour of the nuclear matter formed in nuclear collisions at high energies. Therefore, many experimental results are available at present. For explaining these experimental results a lot of models have been proposed. A very large number of concepts have been used. Taking into account some own experimental results obtained in proton-nucleus and nucleus-nucleus collisions at energies between a few A GeV and a few hundred A GeV we comments in the frame a phenomenological geometric picture the main experimental results on charged particle multiplicities, participants, cross sections, momentum spectra, temperature slopes, nuclear matter flow, size and structure of the participant regions, antiparticle to particle ratios and chemical potential. Some jumps in the dependencies of some interesting physical quantities on the available energies in the centre of mass system can be reported. Trends to behaviours like-saturation of some physical quantities are observed, too. Therefore, some connections with the possible phase transitions in nuclear matter are included. A few specific signals of different phase transitions in nuclear matter are suggested. (authors)

  6. ATTILA (All Type Target Independent Lund Algorithm) for nuclear collisions at ≅ 200 AGeV

    International Nuclear Information System (INIS)

    Gyulassy, M.; Lawrence Berkeley Lab., CA

    1987-08-01

    The Lund string model, Fritiof, is applied in the form of a Monte-Carlo event generator, ATTILA, to nuclear collisions in the 200 AGeV range. We study how uncertainties at the pp level amplify at the AB level and compare preliminary CERN data on multiplicity, transverse energy, and veto energy distributions to this linear extrapolation scheme from pp to AB dynamics. (orig.)

  7. Ex-vacuo nuclear reaction analysis of deuterium

    International Nuclear Information System (INIS)

    Lee, S.R.; Doyle, B.L.

    1989-01-01

    A novel technique for performing in-air d( 3 He, p) nuclear reaction analysis of deuterium using external 3 He ion beams ranging in energy from 0.3-2.0 MeV is presented. Variable on-target beam energies for the depth profiling of deuterium are obtained by varying the transmission distance of the external 3 He beam in air. The ex-vacuo nuclear reaction analysis (XNRA) apparatus is described, and unique aspects and limitations of in-air depth profiling of deuterium using the d( 3 He, p) reaction are discussed. Example analyses where XNRA has been used for the multidimensional measurement of deuterium in fusion reactor components are presented in order to illustrate the advantages of XNRA for deuterium. These advantages include nondestructive analysis of large targets, efficient depth profiling via variable air gap energy tuning, and rapid analysis of numerous samples in the absence of vacuum cycling. (orig.)

  8. High vacuum general purpose scattering chamber for nuclear reaction study

    International Nuclear Information System (INIS)

    Suresh Kumar; Ojha, S.C.

    2003-01-01

    To study the nuclear reactions induced by beam from medium energy accelerators, one of the most common facility required is a scattering chamber. In the scattering chamber, projectile collides with the target nucleus and the scattered reaction products are detected with various type of nuclear detector at different angles with respect to the beam. The experiments are performed under high vacuum to minimize the background reaction and the energy losses of the charged particles. To make the chamber general purpose various requirement of the experiments are incorporated into it. Changing of targets, changing angle of various detectors while in vacuum are the most desired features. The other features like ascertaining the beam spot size and position on the target, minimizing the background counts by proper beam dump, accurate positioning of the detector as per plan etc. are some of the important requirements

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

    International Nuclear Information System (INIS)

    Sarantites, D.G.

    1991-01-01

    The research program of our group touches five areas of nuclear physics: (1) Nuclear structure studies at high spin; (2) Studies at the interface between structure and reactions; (3) Production and study of hot nuclei; (4) Incomplete fusion and fragmentation reactions; and (5) Development and use of novel techniques and instrumentation in the above areas of research. The papers from these areas are discussed in this report

  10. Study of the central collisions in the reactions Ni + Al and Ni + Ni at 28 A.MeV; Etude des collisions centrales dans les reactions Ni + Al et Ni + Ni a 28 A.MeV

    Energy Technology Data Exchange (ETDEWEB)

    Lebreton, L.

    1995-12-01

    The work is in characterisation of mechanisms in the energy range of onset of multifragmentation (excitation energy of composed nucleus around 4 - 5 AMeV). This work focused on an experiment performed at the SARA facility, in Grenoble, using the AMPHORA multi detection array. I have been particularly interested in central collisions in the Ni + Al and Ni + Ni systems. The possibility to detect complete events for Ni + Al, and quasi-complete events for the Ni + Ni case, is the reason of this choice. Furthermore Ni + Ni presents the interest of a symmetrical system, for which the excitation energy per nucleon is maximum. The study of these reactions has been focused on the quasi-complete events (events for which at least 80 % of the total charge has been detected). Heavy ions produced in peripheral collisions are very likely emitted along the beam line or stopped in the plastic detectors, energy thresholds are too high for the quasi-target products detection, consequently by requiring complete or quasi-complete measurement of the total charge, we are able to detect mostly central events. The knowledge of informations like charge, energy or detection angles allows to isolate the source(s) and to reconstruct the size and the excitation energy of the source(s). Comparisons with simulations like sequential emission (GEMINI code), very deep inelastic collision or instantaneous emission (Berliner code) allows to characterise the first stage of the collision (binary collisions or central collisions) and the type of deexcitation of the source(s). Some calculations was also performed with the statistical model code MODGAN. Indeed azimuthal correlations seem to be a good tool in getting more information about involved reaction mechanisms. Comparisons with MODGAN provide information about angular momentum of the source and time delay between emissions of the two particles (separation between sequential or instantaneous process). (author). 69 refs.

  11. Plasma production and hadronization in ultrarelativistic nuclear collisions

    International Nuclear Information System (INIS)

    Kataja, M.

    1990-01-01

    We study the color confinement and hadronization in the thermodynamic limit of the flux tube model, which was recently developed to describe the energy deposition, particle production and the early expansion of plasma in the central region of ultrarelativistic heavy ion collisions. In this purpose, we introduce a concept of an intermediate 'mixed state', which is formed when the original giant flux tube is fragmented into many smaller tubes which contain the plasma and the Abelian color-electric field and which coexist with a dilute hadron gas. This mixed state is an extension of the mixed phase used in the pure hydrodynamic description utilizing the bag equation of state. We study the thermodynamics of this mixed state making use of the bag model and the classical models of color confinement. It appears that in the thermodynamic limit, the mixed state can be considered as a dielectric medium in which the color dielectric constant takes the values between 0 and 1. We also study how the 'equations of electrohydrodynamics', which were formulated in earlier works to describe the evolution of the giant flux tube and plasma, are to be modified due to the dielectric nature of the new transient mixed state. A numeric simulation of a one-dimensional scaling expansion demonstrates the dynamic transition of the system from plasma to hadron phase and the characteristic reheating effect due to this hadronization transition. It is also shown that in the limit of low temperature or large bag constant, this formalism is reduced to the hydrodynamics of hadron gas produced by the fragmentation of multiple strings. (orig.)

  12. Nuclear matter flow in the Kr+Au collisions at 43 MeV/u

    International Nuclear Information System (INIS)

    Bougault, R.; Delaunay, F.; Genoux-Lubain, A.; Lebrun, C.; Lecolley, J.F.; Lefebvres, F.; Louvel, M.; Steckmeyer, J.C.; Aloff, J.C.; Bilwes, B.; Bilwes, R.; Glaser, M.; Rudolf, G.; Scheibling, F.; Stuttge, L.

    1989-01-01

    When heavy nuclei collide at energy far above the Coulomb barrier we may study the property of nuclear matter in temperature and also density regions far away from the equilibrium. We then hope to study dynamical effects related to the compressibility and the two body collision term. At relativistic energies, some collective effects (flow, bounce off) have been established from a shape analysis done with a large number of light particles with Z ≤ 10. For incident energies lower than 100 MeV/u we may expect that the number of nuclear species formed will be smaller and that a large part of the nuclear matter involved in the collision will be shared in a limited number of heavy fragments (Z ≥ 10). If dynamical effects are still present at GANIL energies they ought to manifest themselves through the properties of the produced fragments (masses, emission angles, velocities and correlated variables). We will present an analysis of heavy nuclei collisions at 43 MeV/u based on as exclusive as possible detection of large fragments

  13. Stochastic Nuclear Reaction Theory: Breit-Wigner nuclear noise

    International Nuclear Information System (INIS)

    de Saussure, G.; Perez, R.B.

    1988-01-01

    The purpose of this paper is the application of various statistical tests for the detection of the intermediate structure, which lies immersed in the Breit-Wigner ''noise'' arising from the superposition of many compound nucleus resonances. To this end, neutron capture cross sections are constructed by Monte-Carlo simulations of the compound nucleus, hence providing the ''noise'' component. In a second step intermediate structure is added to the Breit-Wigner noise. The performance of the statistical tests in detecting the intermediate structure is evaluated using mocked-up neutron cross sections as the statistical samples. Afterwards, the statistical tests are applied to actual nuclear cross section data. 10 refs., 1 fig., 2 tabs

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

    International Nuclear Information System (INIS)

    2012-09-01

    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.)

  15. Study of the reactions resulting in heavy fragment formation in the collisions {sup 40}Ar + Cu, Ag and Au at 8 to 115 MeV/u; Etude des reactions avec formation d`un fragment lourd dans les collisions {sup 40}Ar + Cu, Ag et Au de 8 a 115 MeV/u

    Energy Technology Data Exchange (ETDEWEB)

    Colin, Eric Yves [Universite Claude Bernard Lyon-1, 69 - Lyon (France)

    1998-11-06

    This work concerns the study of nuclear collisions showing a heavy fragment in {sup 40}Ar + Cu, Ag and Au from 8 A MeV to 115 A MeV. The reactions are classified by centrality or collision violence via the multiplicity of charged particles detected in a 4{pi} array. For the most peripheral reactions (low multiplicities) we always find a projectile-like fragment with velocity near to that of the beam and a heavy target-like fragment with very small velocity. For the more central collisions we find the well-known incomplete fusion reactions at 17 and 27 A MeV. Above 27 A MeV two groups of very dissipative reactions are observed, both with high charged particle multiplicities. The first reaction group forms several fragments with Z {<=} 10 and average longitudinal velocity near to that of c.m. These are very rare, and are found only for the highest 1% of multiplicities. They produce a heavy fragment and a forward spray ({theta}{<=}60 angle) of particles with charge going from 1 to {approx_equal}13. The momentum carried out by the spray is randomly spread over all the particles. In spite of the increase of momentum carried by this spray with increasing beam energy, a heavy emission source is formed with 1 - 2 GeV of excitation energy. After a phase of expansion, especially signaled by Z = 1 particles, this source then evaporates many particles. Finally we observed the remaining heavy residual nucleus. (author) 117 refs., 85 figs., 12 tabs.

  16. Studies of nuclear second moments for pre-equilibrium nuclear reaction theories

    International Nuclear Information System (INIS)

    Sato, K.; Yoshida, S.

    1987-01-01

    The nuclear second moments, important inputs to pre-equilibrium reaction theories, are evaluated by assuming a simple model. The positive definite nature of the second moments is examined, and the nuclear level densities are calculated using positive definite second moments. (orig.)

  17. Formation of large target residues in intermediate energy nuclear collisions

    International Nuclear Information System (INIS)

    Loveland, W.; Aleklett, K.; Sihver, L.; Xu, Z.; Seaborg, G.T.

    1987-04-01

    We have used radiochemical techniques to measure the yields, angular distributions and velocity spectra of the large (A/sub frag/ ≥ 2/3 A/sub tgt/) target residues from the fragmentation of 197 Au by intermediate energy 12 C, 20 Ne, 32 S, 40 Ar, 84 Kr, and 139 La projectiles. The fragment moving frame angular distributions are asymmetric for the lighter projectiles (C-Ar). The fragment velocity spectra are Maxwellian for the Kr induced reactions and non-Maxwellian for the reactions induced by the lighter ions. We interpret these results in terms of a change in the dominant fragment production mechanism(s) from one(s) involving a fast non-equilibrium process for the lighter ions to a slow, equilibrium process for Kr. Comparison of the measured yields and angular distributions with calculations made using a Boltzmann transport equation with appropriate modifications for Pauli blocking, etc., show excellent agreement between data and theory. 12 refs., 12 figs

  18. Results of the Nonelastic Reaction Code Brieff for Nuclear Data

    International Nuclear Information System (INIS)

    Duarte, H.

    2009-01-01

    We present recent changes in our nonelastic reaction code BRIEFF and especially in the fast stage of reaction described by the intranuclear cascade (INC) code BRIC. Distributions and excitation functions of residual nuclei production cross sections are shown for proton-induced reaction on target nuclei. Slight improvements are seen in the proton-induced reaction on light nuclei with a closed shell when the energy levels are taken into account in the INC stage. On the other hand, fission gives poor results in the current version. To compare to other nuclear models and LA150 libraries, BRIEFF has been incorporated into MCNPX 2.5.0. Examples of neutron production from thick target irradiation by proton beams between 30 and 350 MeV are presented. Except for some discrepancies, a good agreement with data is obtained on average. (authors)

  19. EMPIRE-II statistical model code for nuclear reaction calculations

    Energy Technology Data Exchange (ETDEWEB)

    Herman, M [International Atomic Energy Agency, Vienna (Austria)

    2001-12-15

    EMPIRE II is a nuclear reaction code, comprising various nuclear models, and designed for calculations in the broad range of energies and incident particles. A projectile can be any nucleon or Heavy Ion. The energy range starts just above the resonance region, in the case of neutron projectile, and extends up to few hundreds of MeV for Heavy Ion induced reactions. The code accounts for the major nuclear reaction mechanisms, such as optical model (SCATB), Multistep Direct (ORION + TRISTAN), NVWY Multistep Compound, and the full featured Hauser-Feshbach model. Heavy Ion fusion cross section can be calculated within the simplified coupled channels approach (CCFUS). A comprehensive library of input parameters covers nuclear masses, optical model parameters, ground state deformations, discrete levels and decay schemes, level densities, fission barriers (BARFIT), moments of inertia (MOMFIT), and {gamma}-ray strength functions. Effects of the dynamic deformation of a fast rotating nucleus can be taken into account in the calculations. The results can be converted into the ENDF-VI format using the accompanying code EMPEND. The package contains the full EXFOR library of experimental data. Relevant EXFOR entries are automatically retrieved during the calculations. Plots comparing experimental results with the calculated ones can be produced using X4TOC4 and PLOTC4 codes linked to the rest of the system through bash-shell (UNIX) scripts. The graphic user interface written in Tcl/Tk is provided. (author)

  20. Direct nuclear reactions and the structure of atomic nuclei

    International Nuclear Information System (INIS)

    Osterfeld, F.

    1985-01-01

    The present thesis deals with two different aspects of direct nuclear reactions, namely on the one hand with the microscopic calculation of the imaginary optical potential for the elastic nucleon-nucleus scattering as well as on the other hand with the microscopic analysis of giant magnetic resonances in atomic nuclei which are excited by (p,n) charge-exchange reactions. In the first part of the thesis the imaginary part of the optical potential for the elastic proton- and neutron-nucleus scattering is microscopically calculated in the framework of the so called nuclear-structure approximation to the optical potential. The calculations are performed in the Feshbach formalism in second-order perturbation theory corresponding to an effective projectile-target-nucleon interaction. In the second part of this thesis in the framework of microscopic nuclear models a complete analysis of different A(p,n)B charge-exchange reactions at high incident energies 160 MeV 90 Zr(p,n) reaction three collective spin-isospin resonances could be uniquely identified. (orig./HSI) [de

  1. Nonlinear many-body reaction theories from nuclear mean field approximations

    International Nuclear Information System (INIS)

    Griffin, J.J.

    1983-01-01

    Several methods of utilizing nonlinear mean field propagation in time to describe nuclear reaction have been studied. The property of physical asymptoticity is analyzed in this paper, which guarantees that the prediction by a reaction theory for the physical measurement of internal fragment properties shall not depend upon the precise location of the measuring apparatus. The physical asymptoticity is guaranteed in the Schroedinger collision theory of a scuttering system with translationally invariant interaction by the constancy of the S-matrix elements and by the translational invariance of the internal motion for well-separated fragments. Both conditions are necessary for the physical asymptoticity. The channel asymptotic single-determinantal propagation can be described by the Dirac-TDHF (time dependent Hartree-Fock) time evolution. A new asymptotic Hartree-Fock stationary phase (AHFSP) description together with the S-matrix time-dependent Hartree-Fock (TD-S-HF) theory constitute the second example of a physically asymptotic nonlinear many-body reaction theory. A review of nonlinear mean field many-body reaction theories shows that initial value TDHF is non-asymptotic. The TD-S-HF theory is asymptotic by the construction. The gauge invariant periodic quantized solution of the exact Schroedinger problem has been considered to test whether it includes all of the exact eigenfunctions as it ought to. It did, but included as well an infinity of all spurions solutions. (Kato, T.)

  2. Determination of nuclear friction in strongly damped reactions from prescission neutron multiplicities

    International Nuclear Information System (INIS)

    Wilczynski, J.; Siwek-Wilczynska, K.; Wilschut, H.W.

    1996-01-01

    Nonfusion, fissionlike reactions in collisions of four heavy systems (well below the fusion extra-push energy threshold), for which Hinde and co-workers had measured the prescission neutron multiplicities, have been analyzed in terms of the deterministic dynamic model of Feldmeier coupled to a time-dependent statistical cascade calculation. In order to reproduce the measured prescission multiplicities and the observed (nearly symmetric) mass divisions, the energy dissipation must be dramatically changed with regard to the standard one-body dissipation: In the entrance channel, in the process of forming a composite system, the energy dissipation has to be reduced to at least half of the one-body dissipation strength (k s in ≤0.5), and in the exit channel (from a mononucleus shape to scission) it must be increased by a factor ranging for the studied reactions from k s out =4 to k s out =12. These results are compared with the temperature dependence of the friction coefficient, recently deduced by Hofman, Back, and Paul from data on the prescission giant dipole resonance emission in fusion-fission reactions. The combined picture of the temperature dependence of the friction coefficient, for both fusion-fission and nonfusion reactions, may indicate the onset of strong two-body dissipation already at a nuclear temperature of about 2 MeV. copyright 1996 The American Physical Society

  3. Experimental effects of dynamics and thermodynamics in nuclear reactions on the symmetry energy as seen by the CHIMERA 4 π detector

    Energy Technology Data Exchange (ETDEWEB)

    De Filippo, E.; Pagano, A. [INFN, Catania (Italy)

    2014-02-15

    Heavy-ion collisions have been widely used in the last decade to constrain the parameterizations of the symmetry energy term of the nuclear equation of state (EOS) for asymmetric nuclear matter as a function of baryonic density. In the Fermi energy domain one is faced with variations of the density within a narrow range of values around the saturation density ρ{sub 0}=0.16 fm{sup -3} down towards sub-saturation densities. The experimental observables which are sensitive to the symmetry energy are constructed starting from the detected light particles, clusters and heavy fragments that, in heavy-ion collisions, are generally produced by different emission mechanisms at different stages and time scales of the reaction. In this review the effects of dynamics and thermodynamics on the symmetry energy in nuclear reactions are discussed and characterized using an overview of the data taken so far with the CHIMERA multi detector array. (orig.)

  4. Report of seminar on relativistic approach to nuclear reaction and nuclear structure

    International Nuclear Information System (INIS)

    1986-05-01

    A seminar on 'Relativistic Approach to Nuclear Reaction and Nuclear Structure' was held in 1985 at Osaka University. This booklet includes twenty-four reports given at the seminar, which deal with: Conventional Nonrelativistic Description of Nuclear Matter and Nuclear Spin-Orbit Interactions; Relativistic Approach to Nuclear Structure; Atomic and Molecular Structure Calculations; Electromagnetic Interaction in Nucleus and Relativistic Effect; Nuclear Magnetic Moment in the Relativistic Mean Field Theory, Effective Mass and Particle-Vibration Coupling in the Relativistic σ-ω Model; Gauge Invariance in Relativistic Many-Body Theory; Relativistic Description of Nucleon-Nucleon Interaction in Review; σ-Particle in NN Interaction; Nuclear Optical Potentials Based on the Brueckner-Hartree-Fock Approach; Elastic Backscattering and Optical Potential; Description of Intermediate-Energy Nuclear Reactions; Dirac Phenomenology at E(p) = 65 MeV; Relativistic Impulse Approximation; Reaction Studies with Intermediate Energy Deuterons at SATURNE; Folding Model for Intermediate-Energy Deutron Scattering; Folding Model for Polarized Deutron Scattering at 700 MeV; Dirac Approach Problems and a Different Viewpoint; Relativistic Approach and EMC Effect; Quasielastic Electron Scattering; Response Function of Quasielastic Electron Scattering; Relativistic Hartree Response Function for Quasielastic Electron Scattering on 12 C and 40 Ca; Backflow-, Retardation- and Relativistic Effects on the Longitudinal Response Function of Nuclear Matter; Pion-Photoproduction in the σ-ω Model. (Nogami, K.)

  5. Sigma: Web Retrieval Interface for Nuclear Reaction Data

    International Nuclear Information System (INIS)

    Pritychenko, B.; Sonzogni, A.A.

    2008-01-01

    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

  6. Nuclear Reactions in Micro/Nano-Scale Metal Particles

    International Nuclear Information System (INIS)

    Kim, Y. E.

    2013-01-01

    Low-energy nuclear reactions in micro/nano-scale metal particles are described based on the theory of Bose-Einstein condensation nuclear fusion (BECNF). The BECNF theory is based on a single basic assumption capable of explaining the observed LENR phenomena; deuterons in metals undergo Bose-Einstein condensation. The BECNF theory is also a quantitative predictive physical theory. Experimental tests of the basic assumption and theoretical predictions are proposed. Potential application to energy generation by ignition at low temperatures is described. Generalized theory of BECNF is used to carry out theoretical analyses of recently reported experimental results for hydrogen-nickel system. (author)

  7. Nuclear Reactions in Micro/Nano-Scale Metal Particles

    Science.gov (United States)

    Kim, Y. E.

    2013-03-01

    Low-energy nuclear reactions in micro/nano-scale metal particles are described based on the theory of Bose-Einstein condensation nuclear fusion (BECNF). The BECNF theory is based on a single basic assumption capable of explaining the observed LENR phenomena; deuterons in metals undergo Bose-Einstein condensation. The BECNF theory is also a quantitative predictive physical theory. Experimental tests of the basic assumption and theoretical predictions are proposed. Potential application to energy generation by ignition at low temperatures is described. Generalized theory of BECNF is used to carry out theoretical analyses of recently reported experimental results for hydrogen-nickel system.

  8. Theoretical nuclear reaction and structure studies using hyperons and photons

    International Nuclear Information System (INIS)

    Cotanch, S.R.

    1991-01-01

    This report details research progress and results obtained during the 12 month period from January 1991 through 31 December 1991. The research project, entitled ''Theoretical Nuclear Reaction and Structure Studies Using Hyperons and Photons,'' is supported by grant DE-FG05-88ER40461 between North Carolina State University and the United States Department of Energy. In compliance with grant requirements the Principal Investigator, Professor Stephen R. Cotanch, has conducted a research program addressing theoretical investigations of reactions involving hyperons and photons. The new, significant research results are briefly summarized in the following sections

  9. Annual report of the Grenoble Institute of nuclear science

    International Nuclear Information System (INIS)

    Vignon, B.

    1988-01-01

    Research in theoretical nuclear physics; peripheral reactions and intermediate energy physics; characteristics of reaction mechanisms in heavy ion collisions; nuclear structure; fundamental interactions; interdisciplinary studies; experimental methods and instrumentation; and the SARA accelerator is presented [fr

  10. NMTC/JAM, Simulates High Energy Nuclear Reactions and Nuclear-Meson Transport Processes

    International Nuclear Information System (INIS)

    Furihata, Shiori

    2002-01-01

    1 - Description of program or function: NMTC/JAM is an upgraded version of the code system NMTC/JAERI97. NMTC/JAERI97 simulates high energy nuclear reactions and nucleon-meson transport processes. It implements an intra-nuclear cascade model taking account of the in-medium nuclear effects and the pre-equilibrium calculation model based on the exciton one. For treating the nucleon transport process, the nucleon-nucleus cross sections are revised to those derived by the systematics of Pearlstein. Moreover, the level density parameter derived by Ignatyuk is included as a new option for particle evaporation calculation. A geometry package based on the Combinatorial Geometry with multi-array system and the importance sampling technique is implemented in the code. Tally function is also employed for obtaining such physical quantities as neutron energy spectra, heat deposition and nuclide yield without editing a history file. The code can simulate both the primary spallation reaction and the secondary particle transport in the intermediate energy region from 20 MeV to 3.5 GeV by the use of the Monte Carlo technique. The code has been employed in combination with the neutron-photon transport codes available to the energy region below 20 MeV for neutronics calculation of accelerator-based subcritical reactors, analyses of thick target spallation experimented and so on. 2 - Methods: High energy nuclear reactions induced by incident high energy protons, neutrons and pions are simulated with the Monte Carlo Method by the intra-nuclear nucleon-nucleon reaction probabilities based on an intra-nuclear nucleon cascade model followed by the particle evaporation including high energy fission process. Jet-Aa Microscopic transport model (JAM) is employed to simulate high energy nuclear reactions in the energy range of GeV. All reaction channels are taken into account in the JAM calculation. An intra-nuclear cascade model (ISOBAR code) taking account of the in-medium nuclear effects

  11. Statistical and dynamical aspects of intermediate energy nuclear collisions

    International Nuclear Information System (INIS)

    Ghetti, R.

    1997-01-01

    Studies of intermediate energy heavy ion reactions have revealed that the probability of emitting n-fragments is reducible to the probability of emitting a single fragment through the binomial distribution. The resulting one-fragment probability shows a dependence on the thermal energy that is characteristic of statistical decay. Similarly, the charge distributions associated with n-fragment emission are reducible to the one-fragment charge distribution, and thermal scaling is observed. The reducibility equation for the n-fragment charge distribution contains a quantity with a value that starts from zero, at low transverse energies, and saturates at high transverse energies. This evolution may signal a transition from a coexistence phase to a vapour phase. In the search for a signal of liquid-gas phase transition, the appearance of intermittency is reconsidered. Percolation calculations, as well as data analysis, indicate that an intermittent-like signal appears from classes of events that do not coincide with the critical one. 232 refs

  12. Statistical and dynamical aspects of intermediate energy nuclear collisions

    Energy Technology Data Exchange (ETDEWEB)

    Ghetti, R.

    1997-01-01

    Studies of intermediate energy heavy ion reactions have revealed that the probability of emitting n-fragments is reducible to the probability of emitting a single fragment through the binomial distribution. The resulting one-fragment probability shows a dependence on the thermal energy that is characteristic of statistical decay. Similarly, the charge distributions associated with n-fragment emission are reducible to the one-fragment charge distribution, and thermal scaling is observed. The reducibility equation for the n-fragment charge distribution contains a quantity with a value that starts from zero, at low transverse energies, and saturates at high transverse energies. This evolution may signal a transition from a coexistence phase to a vapour phase. In the search for a signal of liquid-gas phase transition, the appearance of intermittency is reconsidered. Percolation calculations, as well as data analysis, indicate that an intermittent-like signal appears from classes of events that do not coincide with the critical one. 232 refs.

  13. The origin of nuclear spin and its effect durning intermediate energy heavy ion collisions

    International Nuclear Information System (INIS)

    Zhang Guoqiang; Cao Xiguang; Fu Yao; Ma Yugang; Cai Xiangzhou; Wang Hongwei; Fang Deqing; Tian Wendong; Chen Jingen; Guo Wei; Liu Guihua

    2010-01-01

    We use the heavy-ion phase-space exploration (HIPSE) model to discuss the origin of the nuclear spin and its effect in Intermediate energy nuclear reaction. It is found that the spin of projectile depends on the impact parameter of the reaction system heavily, while on the violence lightly by contrast. Some interesting multifragmentation phenomena related to the spin are shown, especially those of phase transition. At the same time, the role of excited energy for multifragmentation is also invested. We find the later plays a more robust role durning the nuclear disintegration. (authors)

  14. Multi-element Analysis of variable sample matrices using collision/reaction cell inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Zahran, N.F.; Helal, A.I.; Amr, M.A.; Amr, M.A.; Al-saad, K.A.

    2008-01-01

    An ICP-MS with an octopole reaction/collision cell is used for the multielement determination of trace elements in water, plants, and soil samples. The use of a reaction or collision gas reduces serious spectral interferences from matrix elements such as Ar Cl or Ar Na. The background equivalent concentration (BEC) is reduced one order of magnitude at helium flow rate of 1 mL/min. Certified reference material namely , NIST Water-1643d, Tomato leaves 1573a, and Montana soil 2711 are used. The trace elements Mn, Fe, Co, Ni, Cu, Zn, As, Mo, Cd and Pb are determined in the different matrices with a accuracy better than 8% to the certified values

  15. 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.

  16. Charged-particle transfer reactions and nuclear astrophysics problems

    International Nuclear Information System (INIS)

    Artemov, S.V.; Yarmukhamedov, R.; Yuldashev, B.S.; Burtebaev, N.; Duysebaev, A.; Kadyrzhanov, K.K.

    2002-01-01

    In the report a review of the recent results of calculation of the astrophysical S-factors S(E) for the D(α, γ) 6 Li, 3 He(α, γ) 7 Be, 7 Be(p, γ) 8 Be, 12,13 C(p, γ) 13, 14 N and 12 C(p,γ) 16 O* reactions at extremely low energies E, including value E=0 , performed within the framework of a new method taking into account the additional information about the nuclear vertex constant (Nc) (or the respective asymptotic normalization coefficient) are presented. The required values of Nc can be obtained from an analysis of measured differential cross-sections of proton and α-particle transfer reactions (for example A( 3 He,d)B, 6 Li(d, 6 Li)d, 6 Li(α, 6 Li)α, 12 C( 6 Li, d) 16 O* etc.). A comparative analysis between the results obtained by different authors is also done. Taking into account an important role of the NVC's values for the nuclear astrophysical A(p, γ)B and A(α, γ)B reactions, a possibility of obtaining the reliable NVC values for the virtual decay B→A+p and B→A+α from the analysis of differential cross sections both sub- and above-barrier A( 3 He, d) and A( 6,7 Li, 2,3 H)B reactions is discussed in detail. In this line the use the isochronous cyclotron U-150 M, the 'DC-60' heavy ion machine and electrostatic charge-exchanging accelerator UKP-2-1 of Institute of Nuclear Physics of National Nuclear Center of the Republic of Kazakhstan for carrying out the needed experiments is considered and the possibility of the obtained data application for the astrophysical interest is also discussed

  17. Alpha-decay within Feshbach theory of nuclear reactions

    International Nuclear Information System (INIS)

    Sandulescu, A.; Silisteanu, I.; Wunsch, R.

    1977-01-01

    In the frame of Feshbach theory of nuclear reactions the alpha-decay widths are determined by the alpha-daughter nucleus optical potential and by the formation factors. It is shown that the calculated absolute values of the alpha widths for Po light isotopes are in good agreement with experimental data, if the real part of the optical potential with the parameters fitted by the low energy α-scattering is used

  18. Rearrangement reactions in ion-ion and ion-atom collisions: results and problems

    Energy Technology Data Exchange (ETDEWEB)

    Presnyakov, L.P. [Lebedev Physical Institute, Moscow (Russian Federation); Tawara, H.

    1997-01-01

    Recent experimental and theoretical results are discussed for ionic collisions with large cross sections at intermediate and small energies of the relative motion. Single- and double-electron removal from H{sup -} ions in slow collisions with other ions is considered in more details. The theoretical methods are discussed from the viewpoint of general requirements of scattering theory. (author)

  19. Forward-backward multiplicity fluctuation and longitudinal harmonics in high-energy nuclear collisions

    Science.gov (United States)

    Jia, Jiangyong; Radhakrishnan, Sooraj; Zhou, Mingliang; Huo, Peng

    2016-12-01

    Forward-backward (FB) multiplicity fluctuation in high-energy nuclear collisions can be quantified by two-particle pseudo-rapidity correlation function and its expansion into Legendre polynomials. The corresponding coefficients represent different fluctuation modes in longitudinal direction. The leading term corresponds to the asymmetry of numbers of the participants from the two colliding nuclei. This method is tested in events generated from AMPT and HIJING model. The an signal are found to be strongly dampened in AMPT than in HIJIGN, due to weaker short-range correlaitons and final-state effects in AMPT. Two-particle correlation also reveals an intresting shallow minimum around Δη ≈ 0 in AMPT events, which is absent in HIJING results. The method opens a new avenue to elucidate the particle production mechanism and early time dynamics in heavy-ion collisions.

  20. Evidence for radial flow of thermal dileptons in high-energy nuclear collisions

    CERN Document Server

    Arnaldi, R; Castor, J; Chaurand, B; Cicalò, C; Colla, A; Cortese, P; Damjanovic, S; David, A; De Falco, A; Devaux, A; Ducroux, L; Enyo, H; Fargeix, J; Ferretti, A; Floris, M; Förster, A; Force, P; Guettet, N; Guichard, A; Gulkanian, H R; Heuser, J M; Keil, M; Kluberg, L; Lourenço, C; Lozano, J; Manso, F; Martins, P; Masoni, A; Neves, A; Ohnishi, H; Oppedisano, C; Parracho, P; Pillot, P; Poghosyan, T; Puddu, G; Radermacher, E; Ramalhete, P; Rosinsky, P; Scomparin, E; Seixas, J; Serci, S; Shahoyan, R; Sonderegger, P; Specht, H J; Tieulent, R; Usai, G; Veenhof, R; Wöhri, H K

    2008-01-01

    The NA60 experiment at the CERN SPS has studied low-mass dimuon production in 158 AGeV In-In collisions. An excess of pairs above the known meson decays has been reported before. We now present precision results on the associated transverse momentum spectra. The slope parameter Teff extracted from the spectra rises with dimuon mass up to the rho, followed by a sudden decline above. While the initial rise is consistent with the expectations for radial flow of a hadronic decay source, the decline signals a transition to an emission source with much smaller flow. This may well represent the first direct evidence for thermal radiation of partonic origin in nuclear collisions.

  1. Activation cross-section data for -particle-induced nuclear reactions ...

    Indian Academy of Sciences (India)

    B M ALI

    2018-02-20

    particle-induced nuclear reactions on natural vanadium up to 20 MeV. It should be mentioned that this study represents a part of (a supplement) systematical study of charged particles-induced nuclear reactions. Earlier studies were.

  2. Isospin splitting of nucleon effective mass and symmetry energy in isotopic nuclear reactions

    Science.gov (United States)

    Guo, Ya-Fei; Chen, Peng-Hui; Niu, Fei; Zhang, Hong-Fei; Jin, Gen-Ming; Feng, Zhao-Qing

    2017-10-01

    Within an isospin and momentum dependent transport model, the dynamics of isospin particles (nucleons and light clusters) in Fermi-energy heavy-ion collisions are investigated for constraining the isospin splitting of nucleon effective mass and the symmetry energy at subsaturation densities. The impacts of the isoscalar and isovector parts of the momentum dependent interaction on the emissions of isospin particles are explored, i.e., the mass splittings of and (). The single and double neutron to proton ratios of free nucleons and light particles are thoroughly investigated in the isotopic nuclear reactions of 112Sn+112Sn and 124Sn+124Sn at incident energies of 50 and 120 MeV/nucleon, respectively. It is found that both the effective mass splitting and symmetry energy impact the kinetic energy spectra of the single ratios, in particular at the high energy tail (larger than 20 MeV). The isospin splitting of nucleon effective mass slightly impacts the double ratio spectra at the energy of 50 MeV/nucleon. A soft symmetry energy with stiffness coefficient of γ s=0.5 is constrained from the experimental data with the Fermi-energy heavy-ion collisions. Supported by Major State Basic Research Development Program in China (2014CB845405, 2015CB856903), National Natural Science Foundation of China (11722546, 11675226, 11675066, U1332207) and Youth Innovation Promotion Association of Chinese Academy of Sciences

  3. Puzzle of the folding potential on the nuclear halo reactions

    International Nuclear Information System (INIS)

    Ismail, Atef; Lee, Yen Cheong; Mahmoud, Z.M.M.

    2015-01-01

    Folding potentials of the elastic scattering drip-line nuclei at various incident energies is one method to study nuclear matter density distributions and nuclear radii. The nuclei with density distributions consisting of a bulk (core) and an outer layer (halo), dilute and spatially extended are called the halo nuclei caused for the weak particle binding. Several halo nuclei are studied and many potential candidates are identified. All the cross-sections of the elastic scattering for the drip-line nuclei 11 Be and 6 He, are calculated to understand the exotic properties of these nuclei starting from its structure, extended radius, nuclear size till the large total reaction cross-sections for these nuclei when it interacts with a stable target 12 C. (author)

  4. Explosion-evaporation model for fragment production in intermediate-energy nuclear collisions

    International Nuclear Information System (INIS)

    Fai, G.; Randrup, J.

    1981-01-01

    Nuclear collisions at intermediate energies may create transient systems of hot nuclear matter that decay into many nuclear fragments. The disassembly of such a nuclear fireball is described as a two-stage process. In the primary explosion stage the system quickly fragments into nucleons and composite nuclei according to the available phase space. The explosion produces excited nuclei with half-lives longer than the time associated with the breakup. In the secondary evaporation stage, these nuclei decay, first by sequential emission of light particles (neutrons, protons, alphas), later by electromagnetic radiation. The secondary stage in general changes the relative abundancies of the various fragment species. This general feature makes it essential to take account of the composite fragments before using d/p as a measure of the entropy of the initial source. The formation of unbound nuclei at the explosion stage also has the desirable effect of enhancing the final abundancies of particularly stable nuclei, e.g., 4 He. For neutron-excessive sources the presence of composite nuclei amplifies the ratio of observed neutrons and protons; this effect persists for heavier mirror systems. Predictions of the model are qualitatively compared to available experimental data. The model offers a convenient way to augment existing dynamical models, such as intra-nuclear cascade and nuclear fluid dynamics, to yield actual nuclear fragments rather than merely matter distributions

  5. Laboratory approaches of nuclear reactions involved in primordial and stellar nucleosynthesis

    International Nuclear Information System (INIS)

    Rolfs, C.; California Inst. of Tech., Pasadena

    1986-01-01

    Laboratory-based studies of primordial and stellar nucleosynthesis are reviewed, with emphasis on the nuclear reactions induced by charged particles. The analytical approach used to investigate nuclear reactions associated with stellar reactions is described, as well as the experimental details and procedures used to investigate nuclear reactions induced by charged particles. The present knowledge of some of the key reactions involved in primordial nucleosynthesis is discussed, along with the progress and problems of nuclear reactions involved in the hydrogen and helium burning phases of a star. Finally, a description is given of new experimental techniques which might be useful for future experiments in the field of nuclear astrophysics. (U.K.)

  6. Molecular treatment of the ion-pair formation reaction in H(1s) + H(1s) collisions

    Energy Technology Data Exchange (ETDEWEB)

    Borondo, F.; Martin, F.; Yaez, M.

    1987-01-01

    All the available theoretical calculations of the cross section for the ion-pair formation reaction H(1s)+H(1s)..-->..H/sup +/H/sup -/(1s/sup 2/) have been performed using methods that are only valid at high collision energies. They get good agreement with the experiments for impact energies greater than 25 keV, but fail completely at smaller energies. In this work we report the cross section for this reaction at impact energies less than 10 keV, calculated in the framework of the impact-parameter approximation and using the molecular method with a common translation factor.

  7. Molecular treatment of the ion-pair formation reaction in H(1s) + H(1s) collisions

    International Nuclear Information System (INIS)

    Borondo, F.; Martin, F.; Yaez, M.

    1987-01-01

    All the available theoretical calculations of the cross section for the ion-pair formation reaction H(1s)+H(1s)→H + H - (1s 2 ) have been performed using methods that are only valid at high collision energies. They get good agreement with the experiments for impact energies greater than 25 keV, but fail completely at smaller energies. In this work we report the cross section for this reaction at impact energies less than 10 keV, calculated in the framework of the impact-parameter approximation and using the molecular method with a common translation factor

  8. Non extensive corrections to stellar nuclear reactions rate

    Energy Technology Data Exchange (ETDEWEB)

    Assuncao, M. [Universidade Federal de Sao Paulo (DCET/UNIFESP), Diadema, SP (Brazil). Dept. de Ciencias Exatas e da Terra; Silveira, F.E.M. [Universidade Federal do ABC, Santo Andre, SP (Brazil). Centro de Ciencias Naturais e Humanas; Lima, J.A.S. [Universidade de Sao Paulo (IAG/USP), SP (Brazil). Inst. de Astronomia, Geofisica e Ciencias Atmosfericas

    2010-07-01

    Full text: Stellar nucleosynthesis is widely accepted as the basic mechanism for creation of chemical elements in the Universe. In particular, nuclear reactions occurring in the Sun are recognized as responsible for its energy generation. The problem of to determine the energy generation mechanism in stars was firstly attacked by Gamow in the framework of his quantum mechanical theory of potential barrier penetration. According to that approach, the reactions rate is calculated by averaging the penetration factor over the velocity distribution of the plasma particles. A randomization of that distribution is expected as a consequence of the reactions. However, diffusion processes in the macroscopic environment should balance the resulting particles number depletion. Therefore, matter, energy, and momentum might steadily flow. In other words, a quasi-stationary equilibrium state must be attained. In this work, the potential barrier penetration approach to stellar nuclear reactions rate has been rediscussed with basis on Tsallis nonextensive statistics. The investigation has been restricted to non-resonant reactions, for which the S-factor can be regarded as a constant. It has been found that, within the extended formulation, the nonextensive q-parameter is constrained to a maximum value. Accordingly, the q-energy has been shown to exhibit a minimum. The q-Gamow peak has been derived and, in connection with the usual Gaussian approximation, the corresponding half q-width has been also estimated. Plots of the q-energy, q-Gamow peak and half q-width for some reactions with stellar physics interest have been produced. (author)

  9. A semi-classical model for the description of angular distribution of light particles emitted in nuclear reactions

    International Nuclear Information System (INIS)

    Zhang Jingshang

    1990-04-01

    A semi-classical model of multi-step direct and compound nuclear reactions has been proposed to describe the angular distributions of light particles emitted in reaction processes induced by nucleons with energies of several tens of MeV. The exact closed solution for the time-dependent master equation of the exciton model is applied. Based on the Fermi gas model, the scattering kernel for two-nucleon collisions includes the influence of the Fermi motion and the Pauli exclusion principle, which give a significant improvement in the description of the rise of the backward distributions. The angle-energy correlation for the first few steps of the collision process (multi-step direct process) yields further improvements in the description of the angular distribution. The pick-up mechanism is employed to describe the composite particle emission. This reasonable physical picture reproduces the experimental data of the energy spectra of composite particles satisfactorily. The angular distribution of the emitted composite particles is determined by an angular factor in terms of the momentum conservation of the nucleons forming the composite cluster. The generalized master equation is employed for the multi-step compound process. Thus a classical approach has been established to calculate the double differential cross sections for all kinds of particles emitted in multi-step nuclear reaction processes. (author). 19 refs, 6 figs, 1 tab

  10. Impact parameter selected nuclear temperatures of hot nuclei from excited state populations for 40Ar+197Au reactions at E/A=25MeV

    International Nuclear Information System (INIS)

    Li Zuyu; He Zhiyong; Duan Limin; Jin Genming; Wu Heyu; Zhang Baoguo; Wen Wanxin; Qi Yujin; Luo Qingzheng; Dai Guangxi; Wang Hongwei

    1997-01-01

    Nuclear temperatures extracted from excited state populations were measured as a function of linear momentum transfer (LMT) for 40 Ar+ 197 Au reactions at 25MeV/nucleon. The emission temperatures increased slightly with increasing linear momentum transfer or decreasing impact parameter. Taking into account the corrections of detection efficiency and sequential feeding from higher-lying states, a temperature of T∼4MeV was deduced for central collisions. For peripheral collisions the extracted temperatures increased with the energy of the particles. (orig.)

  11. Dynamics of nuclear fission and heavy-ion reactions

    International Nuclear Information System (INIS)

    Nix, J.R.; Sierk, A.J.

    1979-01-01

    Large-amplitude collective motion in fission and heavy-ion reactions is studied by solving classical equations of motion for the time evolution of the nuclear shape. In the nuclear potential energy of deformation, the generalized surface energy was calculated by means of a double volume integral of a Yukawa-plus-exponential function, which was obtained by requiring that two semi-infinite slabs of constant-density nuclear matter have minimum energy at zero separation. The collective kinetic energy is calculated for nuclear flow that is a superposition of incompressible, nearly irrotational collective-shape motion and rigid-body rotation. Nuclear dissipation is included by means of the Rayleigh dissipation function, which depends upon the physical mechanism that converts collective energy into internal energy. For both ordinary two-body viscosity and a combined wall and window one-body dissipation, fission-fragment kinetic energies are calculated for the fission of nuclei throughout the periodic table and compare with experimental results. Finally, the one-body dynamics of nucleons inside a cylinder colliding with a moving piston is explicitly studied by solving exactly the collisionless Boltzmann equation for the distribution function. By examining the relative phases of the pressure at the piston and the piston's velocity, a dissipative force and an elastic restoring force can be separately identified. 9 references

  12. 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.

  13. Peripheral collisions in Ar induced reactions between 27 and 44 A.MeV: study of energy dissipation by measuring the correlated neutron multiplicities

    International Nuclear Information System (INIS)

    Guerreau, D.; Doubre, H.; Galin, J.; Pouthas, J.; Jahnke, U.; Jiang, D.X.; Lott, B.; Jacquet, D.

    1988-01-01

    A 4 π detector measuring the neutron multiplicities has been used to investigate the energy dissipation during peripheral collisions in Ar induced reactions around the Fermi Energy. Besides the persistance of direct transfer reactions for the most peripheral collisions, there are strong evidences for the occurrence of quite large energy dissipation, a clear signature for the one body friction to still play a major role at these intermediate energies

  14. Complementarity between neutron capture and heavy-ion reactions in nuclear structure studies

    International Nuclear Information System (INIS)

    Schult, O.W.B.

    1978-01-01

    The study of the complementarity of certain nuclear reactions in nuclear structure studies includes spectroscopic methods, nuclear rotation and coupling of nucleons to the core, and the de-excitation and structure of high lying states. 23 references

  15. Do nuclear collisions create a locally equilibrated quark-gluon plasma?

    Energy Technology Data Exchange (ETDEWEB)

    Romatschke, P. [University of Colorado at Boulder, Department of Physics, 390 UCB, Boulder, CO (United States); University of Colorado, Center for Theory of Quantum Matter, Boulder, CO (United States)

    2017-01-15

    Experimental results on azimuthal correlations in high energy nuclear collisions (nucleus-nucleus, proton-nucleus, and proton-proton) seem to be well described by viscous hydrodynamics. It is often argued that this agreement implies either local thermal equilibrium or at least local isotropy. In this note, I present arguments why this is not the case. Neither local near-equilibrium nor near-isotropy are required in order for hydrodynamics to offer a successful and accurate description of experimental results. However, I predict the breakdown of hydrodynamics at momenta of order seven times the temperature, corresponding to a smallest possible QCD liquid drop size of 0.15 fm. (orig.)

  16. Relativistic nuclear collisions from the EOS experiment at the Bevalac: collective observables and multifragmentation

    International Nuclear Information System (INIS)

    Insolia, A.

    1996-01-01

    The EOS Collaborations has completed an exclusive study of relativistic heavy ion collisions at the Bevalac using a variety of projectile, target and beam energy combinations. We report here results on directed sidewards flow in Au+Au between 0.25 AGeV and 1.2 AGeV, using a standard in-plane transverse momentum analysis. We also report on projectile fragmentation of Au in C at 1 AGeV. An analysis of fluctuations and critical exponents for small systems seems to support the idea that the multifragmentation regime is associated with a liquid gas phase transition in nuclear matter. (authors)

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

    International Nuclear Information System (INIS)

    Nix, J.R.; Sierk, A.J.

    1984-01-01

    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

  18. Nuclear reaction data for IBA applications to cultural heritage diagnostics

    International Nuclear Information System (INIS)

    Maino, G.; Menapace, E.

    2008-01-01

    Main aspects are discussed concerning nuclear reaction cross-sections for PIXE and PIGE (Particle Induced Gamma-ray Emission) analyses, especially referring to cultural heritage diagnostics, within the framework of ion beam analysis (IBA) methods, also reviewing recent results from international Conferences on Nuclear Data for Science and Technology and from NEANSC meetings and IAEA initiatives on the matter.To sum up this work, it is then worth remarking the following items: IBA techniques are powerful tools to derive unique information as for corrosion, degradation and, generally, conservation conditions of materials. Careful analyses of specific systems require accurate evaluations and establishment of complete databases, in particular for stopping powers and relevant cross sections. The physical parameters to be accurately determined are, therefore, nuclear reaction cross sections of importance for NRA analysis of light elements and stopping powers and ranges of light and heavy ions in various matrices. Light elements (H, Li, B, C, N, O, etc.) play an important role as constituents of many important organic as well inorganic materials in historical and artistic objects. To a large extent these materials occur in the near-surface area of a material with altered or degraded composition

  19. Nuclear reaction data for IBA applications to cultural heritage diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Maino, G.; Menapace, E. [Bologna Univ., ENEA (Italy)

    2008-07-01

    Main aspects are discussed concerning nuclear reaction cross-sections for PIXE and PIGE (Particle Induced Gamma-ray Emission) analyses, especially referring to cultural heritage diagnostics, within the framework of ion beam analysis (IBA) methods, also reviewing recent results from international Conferences on Nuclear Data for Science and Technology and from NEANSC meetings and IAEA initiatives on the matter.To sum up this work, it is then worth remarking the following items: IBA techniques are powerful tools to derive unique information as for corrosion, degradation and, generally, conservation conditions of materials. Careful analyses of specific systems require accurate evaluations and establishment of complete databases, in particular for stopping powers and relevant cross sections. The physical parameters to be accurately determined are, therefore, nuclear reaction cross sections of importance for NRA analysis of light elements and stopping powers and ranges of light and heavy ions in various matrices. Light elements (H, Li, B, C, N, O, etc.) play an important role as constituents of many important organic as well inorganic materials in historical and artistic objects. To a large extent these materials occur in the near-surface area of a material with altered or degraded composition.

  20. Measurements of cold nuclear matter effects on J/ψ in the PHENIX experiment via deuteron-gold collisions

    International Nuclear Information System (INIS)

    Cianciolo, Vince

    2008-01-01

    A new calculation of R dAu has been performed using the 2003 d+Au data and the higher-statistics 2005 p+p data. These nuclear modification factors are compared to calculations using nuclear-modified PDFs and a J/ψ breakup cross section is extracted. These values are then used to project the cold nuclear matter effects in Au+Au collisions. Additionally, a more data-driven projection is performed

  1. Exploring reaction mechanisms and their competition in 58Ni+48Ca collisions at E = 25 AMeV

    Directory of Open Access Journals (Sweden)

    Francalanza L.

    2014-03-01

    Full Text Available Latest results concerning the study of central collisions in 58Ni+48Ca reactions at Elab(Ni=25 AMeV are presented. The experimental data, collected with the CHIMERA 4π device, have been analyzed in order to investigate the competition among different reaction mechanisms for central collisions in the Fermi energy domain. The method adopted to perform the centrality selection refers to the global variable “flow angle”, that is related to the event shape in momentum space, as it is determined by the eigenvectors of the experimental kinetic-energy tensor. The main features of the reaction products were explored by using different constraints on some of the relevant observables, such as mass and velocity distributions and their correlations. Much emphasis was devoted to the competition between fusion-evaporation processes with subsequent identification of a heavy residue and a prompt multifragmentation mechanism. The reaction mechanism was simulated in the framework of transport theories (dynamical stochastic BNV calculations, followed by sequential SIMON code and further comparison with dynamical calculations from transport model (QMD, CoMD are in progress. Moreover, an extension of this study taking into account for the light particles has been envisaged.

  2. Non-Abellian field dynamics in the early stage of ultrarelativistic nuclear collisions

    International Nuclear Information System (INIS)

    Rischke, D.H.

    1997-01-01

    It was argued that the gluon field of a large, ultrarelativistic nucleus can be considered as a classical field for small values of the longitudinal momentum fraction x and on transverse momentum scales Λ 2 QCD 2 perpendicular 2 , where μ 2 is the transverse area density of color charges. The authors estimated μ ∼ 0.4 GeV for collisions of Au-nuclei at RHIC energies. Based on this argument, the gluon field produced in a collision of two ultrarelativistic nuclei is computed perturbatively by solving the classical Yang-Mills equations order by order in the strong coupling constant g. It is shown that to first order in g, the spectrum of produced gluons is identical to that obtained in a perturbative quantum calculation of gluon Bremsstrahlung. It is also identical with that of a coherent quantum state generated by independent collisions between the (classical) color charges in the two nuclei. The perturbative solution is unstable under perturbations. The instabilities arise from the non-Abelian terms in the equations of motion for the gluon field, which enter only at higher order in the perturbative solution scheme. The decay rate of the perturbative solution is shown to be of order μ. Since the non-Abelian terms describe the self-interaction of the produced gluon field, and since such interactions lead to thermalization, the decay rate provides an estimate for the thermalization time scale of classical color fields in ultrarelativistic nuclear collisions. For Au-nuclei, this time scale is therefore of order 0.5 fm/c, in agreement with results for the kinetic thermalization time scale

  3. Non-Abellian field dynamics in the early stage of ultrarelativistic nuclear collisions

    Energy Technology Data Exchange (ETDEWEB)

    Rischke, D.H. [Brookhaven National Lab., Upton, NY (United States)

    1997-09-22

    It was argued that the gluon field of a large, ultrarelativistic nucleus can be considered as a classical field for small values of the longitudinal momentum fraction x and on transverse momentum scales {Lambda}{sup 2}{sub QCD} << k{sup 2}{perpendicular} << {mu}{sup 2}, where {mu}{sup 2} is the transverse area density of color charges. The authors estimated {mu} {approx} 0.4 GeV for collisions of Au-nuclei at RHIC energies. Based on this argument, the gluon field produced in a collision of two ultrarelativistic nuclei is computed perturbatively by solving the classical Yang-Mills equations order by order in the strong coupling constant g. It is shown that to first order in g, the spectrum of produced gluons is identical to that obtained in a perturbative quantum calculation of gluon Bremsstrahlung. It is also identical with that of a coherent quantum state generated by independent collisions between the (classical) color charges in the two nuclei. The perturbative solution is unstable under perturbations. The instabilities arise from the non-Abelian terms in the equations of motion for the gluon field, which enter only at higher order in the perturbative solution scheme. The decay rate of the perturbative solution is shown to be of order {mu}. Since the non-Abelian terms describe the self-interaction of the produced gluon field, and since such interactions lead to thermalization, the decay rate provides an estimate for the thermalization time scale of classical color fields in ultrarelativistic nuclear collisions. For Au-nuclei, this time scale is therefore of order 0.5 fm/c, in agreement with results for the kinetic thermalization time scale.

  4. The problem of space nuclear power sources collisions with artificial space objects in near-earth orbits

    International Nuclear Information System (INIS)

    Gafarov, A.A.

    1993-01-01

    Practically all space objects with onboard nuclear power sources stay in earth satellite orbits with an orbital lifetime long enough to reduce their radioactivity to levels presenting no danger for the Earth population. One of the reasons for orbit lifetime reduction can be collisions with other space objects in near-earth orbits. The possible consequence of collisions can be partial, or even complete, destruction of the spacecraft with an onboard nuclear power source; as well as delivery of additional impulse both to the spacecraft and its fragments. It is shown that collisions in orbit do not cause increase of radiation hazard for the Earth population if there is aerodynamic breakup of nuclear power sources into fragments of safe sizes during atmospheric reentry

  5. EXFOR systems manual: Nuclear reaction data exchange format

    International Nuclear Information System (INIS)

    McLane, V.

    1996-07-01

    This document describes EXFOR, the exchange format designed to allow transmission of nuclear reaction data between the members of the Nuclear Data Centers Network. 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. The exchange format, as outlined, is designed to allow 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)

  6. 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.

  7. Experimental Observation of Nuclear Reactions in Palladium and Uranium

    International Nuclear Information System (INIS)

    J. Dufour; D. Murat; X. Dufour; J. Foos

    2001-01-01

    By submitting various metals (Pd, U) containing hydrogen (from 2000 to 700 000 atoms of hydrogen for 1 000 000 atoms of the host metal) to the combined action of electrical currents and magnetic fields, we have observed a sizeable exothermal effect (from 0.1 to 8 W for 500 mg of metal used). This effect is beyond experimental errors, the energy output being typically 130 to 250% of the energy input and not of chemical origin (exothermal effect in the range of 7000 MJ/mol of metal in the case of palladium and of 60 MJ/mol in the case of uranium). New chemical species also appear in the processes metals. It has been shown by a QED calculation that resonances of long lifetime (s), nuclear dimensions (fm), and low energy of formation (eV) could exist. This concept seems to look like the 'shrunken hydrogen atoms' proposed by various authors. It is indeed very different in two ways (a) being a metastable state, it needs energy to be formed (a few eV) and reverts to normal hydrogen after a few seconds, liberating back its energy of formation (it is thus not the source of the energy observed); (b) its formation can be described as the electron spin/proton nuclear spin interaction becoming first order in the lattice environment (whereas it is third order in a normal hydrogen atom). Moreover, we consider that the hydrex cannot yield a neutron because this reaction is strongly endothermic. To explain our results, we put forward the following working hypothesis: In a metal lattice and under proper conditions, the formation of such resonances (metastable state) could be favored. We propose to call them HYDREX, and we assume that they are actually formed in cold fusion (CF) and low-energy nuclear reaction (LENR) experiments. Once formed, a number of HYDREX could gather around a nucleus of the lattice to form a cluster of nuclear size and of very long life time compared to nuclear time (10 -22 s). In this cluster, nuclear rearrangements could take place, yielding mainly 4 He

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

    International Nuclear Information System (INIS)

    1984-10-01

    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.)

  9. Nuclear reactions and the synthesis of new species

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Targets of relatively short-lived, neutron-rich transplutonium isotopes, such as 254 Es, which are produced by the HFIR/TRU, when combined with the capabilities of modern heavy-ion accelerators, offer a unique possibility to expand our knowledge of chemical elements and atomic nuclei toward the limits of nuclear stability. This knowledge should enable us to delineate the forces that eventually terminate the periodic table at its upper end. Specifically, the panel concludes that significant research opportunities exist in several areas, which are highlighted below: Nucleon-transfer reactions between light heavy-ion projectiles (such as 18 O, 22 Ne, or 48 Ca) and 254 Es targets will give access to a completely uncharted region of neutron-rich isotopes. Cold-fusion reactions of 48 Ca projectiles with /sup 254,255/Es targets should yield superheavy nuclei with neutron numbers very close to the predicted closed neutron shell at N = 184

  10. Microanalysis of solid surfaces by nuclear reactions and elastic scattering

    International Nuclear Information System (INIS)

    Agius, B.

    1975-01-01

    The principles involved in the use of monokinetic light ions beams, of about 1MeV, to the study of surface phenomena are presented. Two complementary techniques are described: the use of elastic scattering, which allows the analysis of impurity elements heavier than the substrate components and the use of nuclear reactions specific of light elements. Typical sensitivities are of the order of 10 11 at/cm 2 in good cases. The depth resolution varies, according to the cases, from about a hundred angstroems to a few thousand angstroems [fr

  11. Development of IAEA nuclear reaction databases and services

    Energy Technology Data Exchange (ETDEWEB)

    Zerkin, V.; Trkov, A. [International Atomic Energy Agency, Dept. of Nuclear Sciences and Applications, Vienna (Austria)

    2008-07-01

    From mid-2004 onwards, the major nuclear reaction databases (EXFOR, CINDA and Endf) and services (Web and CD-Roms retrieval systems and specialized applications) have been functioning within a modern computing environment as multi-platform software, working under several operating systems with relational databases. Subsequent work at the IAEA has focused on three areas of development: revision and extension of the contents of the databases; extension and improvement of the functionality and integrity of the retrieval systems; development of software for database maintenance and system deployment. (authors)

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

    International Nuclear Information System (INIS)

    Toussaint, Udo von; Schwarz-Selinger, Thomas; Gori, Silvio

    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 possible gains. Application of the posterior sampling method allows to optimize the experimental settings interactively during the measurement process.

  13. Nuclear fission: reaction to the discovery in 1939

    International Nuclear Information System (INIS)

    Badash, L.; Hodes, E.; Tiddens, A.

    1985-01-01

    Historical aspects of the behavior of scientists in the aftermath of the discovery of nuclear fission are presented. An extensive background section is given which documents the worldwide discussion of atomic energy over the preceding four decades. A second section briefly surveys the research highlights of 1939. The third section examines the reactions of scientists, primarily in the United States, and includes coverage by newspapers, magazines and radio. The final section includes a number of themes to explain why there was little acknowledgment of the potential of the bomb to affect personal morality, the scientific community and international relations

  14. Energy gains from lattice-enabled nuclear reactions

    International Nuclear Information System (INIS)

    Nagel, David J.

    2015-01-01

    The energy gain of a system is defined as the ratio of its output energy divided by the energy provided to operate the system. Most familiar systems have energy gains less than one due to various inefficiencies. By contrast, lattice-enabled nuclear reactions (LENR) offer high energy gains. Theoretical values in excess of 1000 are possible. Energy gains over 100 have already been reported. But, they have not yet been sustained for commercially significant durations. This article summarizes the current status of LENR energy gains. (author)

  15. Nuclear Modification Factor RpA of b jets in pPb collisions

    CERN Document Server

    CMS Collaboration

    2014-01-01

    We present a measurement of the nuclear modification factor $R_{\\mathrm{pA}}^{\\mathrm{PYTHIA}}$ of b jets in proton-lead collisions from CMS. Jets from b-quark fragmentations are found by exploiting the long lifetime of the b-quark through tagging methods using distributions of the secondary vertex displacement. From these, b-jet cross-sections are calculated and compared to a pp cross-section obtained from a PYTHIA simulation. The $R_{\\mathrm{pA}}^{\\mathrm{PYTHIA}}$ is consistent with unity within systematic uncertainties and may show slight enhancement due to cold nuclear matter effects for a wide range in pseudorapidity. These effects are qualitatively consistent with the observed value for the inclusive jet $R_{\\mathrm{pA}}$. We use 35 nb$^{-1}$ of proton-lead data collected during the 2013 heavy-ion run at the LHC.

  16. Nuclear collisions at several tens of MeV per nucleus

    International Nuclear Information System (INIS)

    Randrup, J.

    1979-10-01

    Nuclear beams with energies of several tens of MeV per nucleon will soon be available at a number of research centers around the world. Such beams offer a tool for probing new aspects of nuclear structure and dynamics. As the energy is raised models and concepts developed for the relatively well studied lower energy domain will be pressed to their limits and are likely to grow obsolete as novel phenomena enter the scene. The theory of ordinary damped collisions is considered; the testing of such theories is one important aspect of the research with higher beam energies. Another is the search for truly novel phenomena, and some more speculative material on that aspect are given. 15 references

  17. Semihard interactions in nuclear collisions based on a unified approach to high energy scattering

    International Nuclear Information System (INIS)

    Drescher, H.J.; Hladik, M.; Werner, K.; Ostapchenko, S.; Centre National de la Recherche Scientifique, 44 - Nantes

    1998-01-01

    Our ultimate goal is the construction of a model for interactions of two nuclei in the energy range between several tens of GeV up to several TeV per nucleon in the centre-of-mass system. Such nuclear collisions are very complex, being composed of many components, and therefore some strategy is needed to construct a reliable model. The central point of our approach is the hypothesis, that the behavior of high energy interactions is universal (universality hypothesis). A model for nuclear interactions in a modular fashion is proposed. The individual modules, based on the universality hypothesis, are identified as building blocks for more elementary interactions (like e + e - , lepton-proton), and can therefore be studied in a much simpler context. With these building blocks under control, a quite reliable model is developed for nucleus-nucleus scattering, providing in particular very useful tests for the complicated numerical procedures using Monte Carlo techniques. (author)

  18. Nuclear collisions at several tens of MeV per nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Randrup, J.

    1979-10-01

    Nuclear beams with energies of several tens of MeV per nucleon will soon be available at a number of research centers around the world. Such beams offer a tool for probing new aspects of nuclear structure and dynamics. As the energy is raised models and concepts developed for the relatively well studied lower energy domain will be pressed to their limits and are likely to grow obsolete as novel phenomena enter the scene. The theory of ordinary damped collisions is considered; the testing of such theories is one important aspect of the research with higher beam energies. Another is the search for truly novel phenomena, and some more speculative material on that aspect are given. 15 references.

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

    International Nuclear Information System (INIS)

    Boboshin, I.N.; Varlamov, V.V.; Komarov, S.Yu.; Peskov, N.N.; Semin, S.B.; Stepanov, M.E.; Chesnokov, V.V.

    2002-01-01

    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.)

  20. Probing the nuclear matter at high baryon and isospin density with heavy ion collisions

    International Nuclear Information System (INIS)

    Di Toro, M.; Colonna, M.; Ferini, G.

    2010-01-01

    Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium nuclear interaction in regions away from saturation. High Energy Collisions are studied in order to access nuclear matter properties at high density. Particular attention is devoted to the selection of observables sensitive to the poorly known symmetry energy at high baryon density, of large fundamental interest, even for the astrophysics implications. Using fully consistent covariant transport simulations built on effective field theories we are testing isospin observables ranging from nucleon/cluster emissions, collective flows (in particular the elliptic, squeeze out, part) and meson production. The possibility to shed light on the controversial neutron/proton effective mass splitting in asymmetric matter is also stressed. The "symmetry" repulsion at high baryon density will also lead to an "earlier" hadron-deconfinement transition in n-rich matter. The phase transition of hadronic to quark matter at high baryon and isospin density is analyzed. Nonlinear relativistic mean field models are used to describe hadronic matter, and the MIT bag model is adopted for quark matter. The boundaries of the mixed phase and the related critical points for symmetric and asymmetric matter are obtained. Isospin effects appear to be rather significant. The binodal transition line of the (T,ρ B ) diagram is lowered in a region accessible to heavy ion collisions in the energy range of the new planned FAIR/NICA facilities. Some observable effects of the mixed phase are suggested, in particular a neutron distillation mechanism. Theoretically a very important problem appears to be the suitable treatment of the isovector part of the interaction in effective QCD lagrangian approaches. (author)