International Nuclear Information System (INIS)
Cruz, Norman; Palma, Guillermo; Zambrano, David; Avelino, Arturo
2013-01-01
We explore a cosmological model composed by a dark matter fluid interacting with a dark energy fluid. The interaction term has the non-linear λρ m α ρ e β form, where ρ m and ρ e are the energy densities of the dark matter and dark energy, respectively. The parameters α and β are in principle not constrained to take any particular values, and were estimated from observations. We perform an analytical study of the evolution equations, finding the fixed points and their stability properties in order to characterize suitable physical regions in the phase space of the dark matter and dark energy densities. The constants (λ,α,β) as well as w m and w e of the EoS of dark matter and dark energy respectively, were estimated using the cosmological observations of the type Ia supernovae and the Hubble expansion rate H(z) data sets. We find that the best estimated values for the free parameters of the model correspond to a warm dark matter interacting with a phantom dark energy component, with a well goodness-of-fit to data. However, using the Bayesian Information Criterion (BIC) we find that this model is overcame by a warm dark matter – phantom dark energy model without interaction, as well as by the ΛCDM model. We find also a large dispersion on the best estimated values of the (λ,α,β) parameters, so even if we are not able to set strong constraints on their values, given the goodness-of-fit to data of the model, we find that a large variety of theirs values are well compatible with the observational data used
Kang, Dongdong; Dai, Jiayu
2018-02-01
The structural, thermodynamic and transport properties of warm dense matter (WDM) are crucial to the fields of astrophysics and planet science, as well as inertial confinement fusion. WDM refers to the states of matter in a regime of temperature and density between cold condensed matter and hot ideal plasmas, where the density is from near-solid up to ten times solid density, and the temperature between 0.1 and 100 eV. In the WDM regime, matter exhibits moderately or strongly coupled, partially degenerate properties. Therefore, the methods used to deal with condensed matter and isolated atoms need to be properly validated for WDM. It is therefore a big challenge to understand WDM within a unified theoretical description with reliable accuracy. Here, we review the progress in the theoretical study of WDM with state-of-the-art simulations, i.e. quantum Langevin molecular dynamics and first principles path integral molecular dynamics. The related applications for WDM are also included.
Fermi liquid, clustering, and structure factor in dilute warm nuclear matter
Röpke, G.; Voskresensky, D. N.; Kryukov, I. A.; Blaschke, D.
2018-02-01
Properties of nuclear systems at subsaturation densities can be obtained from different approaches. We demonstrate the use of the density autocorrelation function which is related to the isothermal compressibility and, after integration, to the equation of state. This way we connect the Landau Fermi liquid theory well elaborated in nuclear physics with the approaches to dilute nuclear matter describing cluster formation. A quantum statistical approach is presented, based on the cluster decomposition of the polarization function. The fundamental quantity to be calculated is the dynamic structure factor. Comparing with the Landau Fermi liquid theory which is reproduced in lowest approximation, the account of bound state formation and continuum correlations gives the correct low-density result as described by the second virial coefficient and by the mass action law (nuclear statistical equilibrium). Going to higher densities, the inclusion of medium effects is more involved compared with other quantum statistical approaches, but the relation to the Landau Fermi liquid theory gives a promising approach to describe not only thermodynamic but also collective excitations and non-equilibrium properties of nuclear systems in a wide region of the phase diagram.
Warm Dense Matter: An Overview
International Nuclear Information System (INIS)
Kalantar, D H; Lee, R W; Molitoris, J D
2004-01-01
This document provides a summary of the ''LLNL Workshop on Extreme States of Materials: Warm Dense Matter to NIF'' which was held on 20, 21, and 22 February 2002 at the Wente Conference Center in Livermore, CA. The warm dense matter regime, the transitional phase space region between cold material and hot plasma, is presently poorly understood. The drive to understand the nature of matter in this regime is sparking scientific activity worldwide. In addition to pure scientific interest, finite temperature dense matter occurs in the regimes of interest to the SSMP (Stockpile Stewardship Materials Program). So that obtaining a better understanding of WDM is important to performing effective experiments at, e.g., NIF, a primary mission of LLNL. At this workshop we examined current experimental and theoretical work performed at, and in conjunction with, LLNL to focus future activities and define our role in this rapidly emerging research area. On the experimental front LLNL plays a leading role in three of the five relevant areas and has the opportunity to become a major player in the other two. Discussion at the workshop indicated that the path forward for the experimental efforts at LLNL were two fold: First, we are doing reasonable baseline work at SPLs, HE, and High Energy Lasers with more effort encouraged. Second, we need to plan effectively for the next evolution in large scale facilities, both laser (NIF) and Light/Beam sources (LCLS/TESLA and GSI) Theoretically, LLNL has major research advantages in areas as diverse as the thermochemical approach to warm dense matter equations of state to first principles molecular dynamics simulations. However, it was clear that there is much work to be done theoretically to understand warm dense matter. Further, there is a need for a close collaboration between the generation of verifiable experimental data that can provide benchmarks of both the experimental techniques and the theoretical capabilities. The conclusion of this
Self-interacting warm dark matter
International Nuclear Information System (INIS)
Hannestad, Steen; Scherrer, Robert J.
2000-01-01
It has been shown by many independent studies that the cold dark matter scenario produces singular galactic dark halos, in strong contrast with observations. Possible remedies are that either the dark matter is warm so that it has significant thermal motion or that the dark matter has strong self-interactions. We combine these ideas to calculate the linear mass power spectrum and the spectrum of cosmic microwave background (CMB) fluctuations for self-interacting warm dark matter. Our results indicate that such models have more power on small scales than is the case for the standard warm dark matter model, with a CMB fluctuation spectrum which is nearly indistinguishable from standard cold dark matter. This enhanced small-scale power may provide better agreement with the observations than does standard warm dark matter. (c) 2000 The American Physical Society
Global warming and nuclear power
International Nuclear Information System (INIS)
Hodgson, P.E.
1999-01-01
The problems of pollution, global warming and renewable energy sources are not going to go away. Governments need to act with urgency if they are to produce a long-term energy policy. This paper looks at the current energy situation, and how this would project into the future without the instigation of radical changes. It concludes that nuclear is the best option available for averting a growing energy, pollution and global warming crisis. (author)
International Nuclear Information System (INIS)
Mortimer, N.
1989-01-01
The greenhouse effect and global warming is a major environmental issue. The nuclear industry has taken this opportunity to promote itself as providing clean energy without implication in either the greenhouse effect or acid rain. However, it is acknowledged that nuclear power does have its own environment concerns. Two questions are posed -does nuclear power contribute to carbon dioxide emissions and can nuclear power provide a realistic long-term solution to global warming? Although nuclear power stations do not emit carbon dioxide, emissions occur during the manufacture of reactor components, the operation of the nuclear fuel cycle and especially, during the mining and processing of the uranium ore. It is estimated that the supply of high grade ores will last only 23 years, beyond that the carbon dioxide emitted during the processing is estimated to be as great as the carbon dioxide emitted from an coal-fired reactor. Fast breeder reactors are dismissed as unable to provide an answer, so it is concluded that nuclear technology has only a very limited role to play in countering global warming.(UK)
Interacting dark matter disguised as warm dark matter
International Nuclear Information System (INIS)
Boehm, Celine; Riazuelo, Alain; Hansen, Steen H.; Schaeffer, Richard
2002-01-01
We explore some of the consequences of dark-matter-photon interactions on structure formation, focusing on the evolution of cosmological perturbations and performing both an analytical and a numerical study. We compute the cosmic microwave background anisotropies and matter power spectrum in this class of models. We find, as the main result, that when dark matter and photons are coupled, dark matter perturbations can experience a new damping regime in addition to the usual collisional Silk damping effect. Such dark matter particles (having quite large photon interactions) behave like cold dark matter or warm dark matter as far as the cosmic microwave background anisotropies or matter power spectrum are concerned, respectively. These dark-matter-photon interactions leave specific imprints at sufficiently small scales on both of these two spectra, which may allow us to put new constraints on the acceptable photon-dark-matter interactions. Under the conservative assumption that the abundance of 10 12 M · galaxies is correctly given by the cold dark matter, and without any knowledge of the abundance of smaller objects, we obtain the limit on the ratio of the dark-matter-photon cross section to the dark matter mass σ γ-DM /m DM -6 σ Th /(100 GeV)≅6x10 -33 cm 2 GeV -1
Global warming and nuclear power
Energy Technology Data Exchange (ETDEWEB)
Wood, L., LLNL
1998-07-10
Nuclear fission power reactors represent a potential solution to many aspects of global change possibly induced by inputting of either particulate or carbon or sulfur oxides into the Earth`s atmosphere. Of proven technological feasibility, they presently produce high-grade heat for large-scale electricity generation, space heating and industrial process-energizing around the world, without emitting greenhouse gases or atmospheric particulates; importantly, electricity production costs from the best nuclear plants presently are closely comparable with those of the best fossil-fired plants. However, a substantial number of issues currently stand between nuclear power and widespread substitution for large stationary fossil fuel-fired systems. These include perceptual ones regarding both long-term and acute operational safety, plant decommissioning, fuel reprocessing, radwaste disposal, fissile materials diversion to military purposes and - perhaps most seriously- readily quantifiable concerns regarding long-term fuel supply and total unit electrical energy cost. We sketch a road-map for proceeding from the present situation toward a nuclear power-intensive world, addressing along the way each of the concerns which presently impede widespread nuclear substitution for fossil fuels, particularly for coal in the most populous and rapidly developing portions of the world, e.g., China and India. This `design to societal specifications` approach to large-scale nuclear fission power systems may lead to energy sources meeting essentially all stationary demands for high-temperature heat. Such advanced options offer a human population of ten billion the electricity supply levels currently enjoyed by Americans for 10,000 years. Nuclear power systems tailored to local needs-and-interests and having a common advanced technology base could reduce present-day world-wide C0{sub 2} emissions by two-fold, if universally employed. By application to small mobile demands, a second two
Response of organic matter quality in permafrost soils to warming
Plaza, C.; Pegoraro, E.; Schuur, E.
2016-12-01
Global warming is predicted to thaw large quantities of the perennially frozen organic matter stored in northern permafrost soils. Upon thaw, this organic matter will be exposed to lateral export to water bodies and to microbial decomposition, which may exacerbate climate change by releasing significant amounts of greenhouse gases. To gain an insight into these processes, we investigated how the quality of permafrost soil organic matter responded to five years of warming. In particular, we sampled control and experimentally warmed soils in 2009 and 2013 from an experiment established in 2008 in a moist acidic tundra ecosystem in Healy, Alaska. We examined surface organic (0 to 15 cm), deep organic (15 to 35 cm), and mineral soil layers (35 to 55 cm) separately by means of stable isotope analysis (δ13C and δ15N) and solid-state 13C nuclear magnetic resonance. Compared to the control, the experimental warming did not affect the isotopic and molecular composition of soil organic matter across the depth profile. However, we did find significant changes with time. In particular, in the surface organic layer, δ13C decreased and alkyl/O-alkyl ratio increased from 2009 to 2013, which indicated variations in soil organic sources (e.g., changes in vegetation) and accelerated decomposition. In the deep organic layer, we found a slight increase in δ15N with time. In the mineral layer, δ13C values decreased slightly, whereas alkyl C/O-alkyl ratio increased, suggesting a preferential loss of relatively more degraded organic matter fractions probably by lateral transport by water flowing through the soil. Acknowledgements: This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 654132. Web site: http://vulcan.comule.com
International Nuclear Information System (INIS)
Negele, J.W.; Zabolitzky, J.G.
1978-01-01
It is stated that at the Workshop on Nuclear and Dense Matter held at the University of Illinois in May 1977 significant progress was reported that largely resolves many of the questions raised in this journal Vol. 6, p.149, 1976. These include perturbative versus variational methods as applied to nuclear matter, exact solutions for bosons, what is known as the fermion 'homework problem', and various other considerations regarding nuclear matter, including the use of variational methods as opposed to perturbation theory. (15 references) (U.K.)
Global warming and nuclear power
Energy Technology Data Exchange (ETDEWEB)
Hodgson, P.E. [Nuclear and Particle Physics Laboratory, Department of Physics, Oxford Univ., Oxford (United Kingdom)
1999-09-01
The concentration of carbon dioxide in the atmosphere is steadily increasing and it is widely believed that this will lead to global warming that will have serious consequences for life on earth. The Intergovernmental Panel on Climate Change has estimated that the temperature of the earth will increase by between 1 and 3.5 degrees in the next century. This will melt some of the Antarctic ice cap, raise the sea level and flood many low-lying countries, and also produce unpredictable changes in the earth's climate. The possible ways of reducing carbon dioxide emission are discussed. It is essential to reduce the burning of fossil fuels, but then how are we to obtain the energy we need? We can try to reduce energy use, but we will still need to generate large amounts energy. Some possible ways of doing this are by using wind and solar generators, by hydroelectric and tidal plants, and also by nuclear power. These possibilities will be critically examined. (author)
Global warming and nuclear power
International Nuclear Information System (INIS)
Hodgson, P.E.
1999-01-01
The concentration of carbon dioxide in the atmosphere is steadily increasing and it is widely believed that this will lead to global warming that will have serious consequences for life on earth. The Intergovernmental Panel on Climate Change has estimated that the temperature of the earth will increase by between 1 and 3.5 degrees in the next century. This will melt some of the Antarctic ice cap, raise the sea level and flood many low-lying countries, and also produce unpredictable changes in the earth's climate. The possible ways of reducing carbon dioxide emission are discussed. It is essential to reduce the burning of fossil fuels, but then how are we to obtain the energy we need? We can try to reduce energy use, but we will still need to generate large amounts energy. Some possible ways of doing this are by using wind and solar generators, by hydroelectric and tidal plants, and also by nuclear power. These possibilities will be critically examined. (author)
Warm Dark Matter and Cosmic Reionization
Villanueva-Domingo, Pablo; Gnedin, Nickolay Y.; Mena, Olga
2018-01-01
In models with dark matter made of particles with keV masses, such as a sterile neutrino, small-scale density perturbations are suppressed, delaying the period at which the lowest mass galaxies are formed and therefore shifting the reionization processes to later epochs. In this study, focusing on Warm Dark Matter (WDM) with masses close to its present lower bound, i.e., around the 3 keV region, we derive constraints from galaxy luminosity functions, the ionization history and the Gunn–Peterson effect. We show that even if star formation efficiency in the simulations is adjusted to match the observed UV galaxy luminosity functions in both CDM and WDM models, the full distribution of Gunn–Peterson optical depth retains the strong signature of delayed reionization in the WDM model. However, until the star formation and stellar feedback model used in modern galaxy formation simulations is constrained better, any conclusions on the nature of dark matter derived from reionization observables remain model-dependent.
Frontiers and challenges in warm dense matter
Desjarlais, Michael; Redmer, Ronald; Trickey, Samuel
2014-01-01
Warm Dense Matter (WDM) occupies a loosely defined region of phase space intermediate between solid, liquid, gas, and plasma, and typically shares characteristics of two or more of these phases. WDM is generally associated with the combination of strongly coupled ions and moderately degenerate electrons, and careful attention to quantum physics and electronic structure is essential. The lack of a small perturbation parameter greatly limits approximate attempts at its accurate description. Since WDM resides at the intersection of solid state and high energy density physics, many high energy density physics (HEDP) experiments pass through this difficult region of phase space. Thus, understanding and modeling WDM is key to the success of experiments on diverse facilities. These include the National Ignition Campaign centered on the National Ignition Facility (NIF), pulsed-power driven experiments on the Z machine, ion-beam-driven WDM experiments on the NDCX-II, and fundamental WDM research at the Linear Coherent...
International Nuclear Information System (INIS)
King, Stephen F.; Merle, Alexander
2012-01-01
We propose a simple model for Warm Dark Matter (WDM) in which two fermions are added to the Standard Model: (quasi-) stable ''keVins'' (keV inert fermions) which account for WDM and their unstable brothers, the ''GeVins'' (GeV inert fermions), both of which carry zero electric charge and zero lepton number, and are (approximately) ''inert'', in the sense that their only interactions are via suppressed couplings to the Z. We consider scenarios in which stable keVins are thermally produced and their abundance is subsequently diluted by entropy production from the decays of the heavier unstable GeVins. This mechanism could be implemented in a wide variety of models, including E 6 inspired supersymmetric models or models involving sterile neutrinos
International Nuclear Information System (INIS)
Negele, J.W.
1977-01-01
Recent advances in variational and perturbative theories are surveyed which offer genuine promise that nuclear matter will soon become a viable tool for investigating nuclear interactions. The basic elements of the hypernetted chain expansion for Jastrow variational functions are briefly reviewed, and comparisons of variational and perturbative results for a series of increasingly complicated systems are presented. Prospects for investigating realistic forces are assessed and the unresolved, open problems are summarized
International Nuclear Information System (INIS)
Besliu, C.; Popa, L.; Popa, V.
1992-01-01
We discuss some recent ideas concerning the structure and the properties of the dibaryonic resonances, with special emphasis on their behaviour when produced in dense nuclear matter. Some features of their de-excitation mechanism and consequent experimentally identifiable signatures are predicted. (Author)
Can global warming save nuclear power?
International Nuclear Information System (INIS)
Pearce, D.
1994-01-01
Nuclear powered electricity generation in the United Kingdom has an uncertain future. The relative costs of generating electricity by nuclear fission compared to other means and the need for a desirable mixture or ''portfolio'' of energy sources in the electricity industry are identified as the key to this uncertainty. The author argues that Government commitments to reducing Carbon Monoxide (CO) emissions, and hence global warming, may strengthen arguments in favour of a firm commitment to nuclear power, as even modern fossil-fuelled power plants emit nearly 90 times as much CO as nuclear plants. (UK)
Experimental Studies of the Transport Parameters of Warm Dense Matter
Energy Technology Data Exchange (ETDEWEB)
Chouffani, Khalid [Idaho State Univ., Pocatello, ID (United States)
2014-12-01
There is a need to establish fundamental properties of matter and energy under extreme physical conditions. Although high energy density physics (HEDP) research spans a wide range of plasma conditions, there is one unifying regime that is of particular importance and complexity: that of warm dense matter, the transitional state between solid state condensed matter and energetic plasmas. Most laboratory experimental conditions, including inertial confinement implosion, fall into this regime. Because all aspects of laboratory-created high-energy-density plasmas transition through the warm dense matter regime, understanding the fundamental properties to determine how matter and energy interact in this regime is an important aspect of major research efforts in HEDP. Improved understanding of warm dense matter would have significant and wide-ranging impact on HEDP science, from helping to explain wire initiation studies on the Sandia Z machine to increasing the predictive power of inertial confinement fusion modeling. The central goal or objective of our proposed research is to experimentally determine the electrical resistivity, temperature, density, and average ionization state of a variety of materials in the warm dense matter regime, without the use of theoretical calculations. Since the lack of an accurate energy of state (EOS) model is primarily due to the lack of experimental data, we propose an experimental study of the transport coefficients of warm dense matter.
International Nuclear Information System (INIS)
Kolomeitsev, E.E.
1997-02-01
The subject of the doctoral thesis is examination of the properties of kaons in nuclear matter. A specific method is explained that has been developed for the scientific objectives of the thesis and permits description of the kaon-nucleon interactions and kaon-nucleon scattering in a vacuum. The main challenge involved was to find approaches that would enable application of the derived relations out of the kaon mass shell, connected with the second objective, namely to possibly find methods which are independent of models. The way chosen to achieve this goal relied on application of reduction formulas as well as current algebra relations and the PCAC hypothesis. (orig./CB) [de
Warm dense matter and Thomson scattering at FLASH
International Nuclear Information System (INIS)
Faeustlin, Roland Rainer
2010-05-01
X-ray free electron lasers are powerful tools to investigate moderately to strongly correlated solid density low temperature plasmas, named warm dense matter. These plasmas are of most interest for astrophysics and laser plasma interaction, particularly inertial confinement fusion. This work utilizes the ultrashort soft x-ray pulse duration and high brilliance of the free electron laser in Hamburg, FLASH, to generate warm dense matter and to study its ultrafast processes. The techniques applied are absorption measurement, emission spectroscopy and Thomson scattering. Radiative hydrodynamics and Thomson scattering simulations are used to investigate the impact of temperature and density gradients in the sample and to fit the experimental data. The measurements result in a comprehensive picture of soft x-ray matter interaction related to warm dense matter and yield insight into ultrafast equilibration and relaxation mechanisms, in particular impact ionization and radiative recombination. (orig.)
Warm dense matter and Thomson scattering at FLASH
Energy Technology Data Exchange (ETDEWEB)
Faeustlin, Roland Rainer
2010-05-15
X-ray free electron lasers are powerful tools to investigate moderately to strongly correlated solid density low temperature plasmas, named warm dense matter. These plasmas are of most interest for astrophysics and laser plasma interaction, particularly inertial confinement fusion. This work utilizes the ultrashort soft x-ray pulse duration and high brilliance of the free electron laser in Hamburg, FLASH, to generate warm dense matter and to study its ultrafast processes. The techniques applied are absorption measurement, emission spectroscopy and Thomson scattering. Radiative hydrodynamics and Thomson scattering simulations are used to investigate the impact of temperature and density gradients in the sample and to fit the experimental data. The measurements result in a comprehensive picture of soft x-ray matter interaction related to warm dense matter and yield insight into ultrafast equilibration and relaxation mechanisms, in particular impact ionization and radiative recombination. (orig.)
Condensed Matter Nuclear Science
Biberian, Jean-Paul
2006-02-01
1. General. A tribute to gene Mallove - the "Genie" reactor / K. Wallace and R. Stringham. An update of LENR for ICCF-11 (short course, 10/31/04) / E. Storms. New physical effects in metal deuterides / P. L. Hagelstein ... [et al.]. Reproducibility, controllability, and optimization of LENR experiments / D. J. Nagel -- 2. Experiments. Electrochemistry. Evidence of electromagnetic radiation from Ni-H systems / S. Focardi ... [et al.]. Superwave reality / I. Dardik. Excess heat in electrolysis experiments at energetics technologies / I. Dardik ... [et al.]. "Excess heat" during electrolysis in platinum/K[symbol]CO[symbol]/nickel light water system / J. Tian ... [et al.]. Innovative procedure for the, in situ, measurement of the resistive thermal coefficient of H(D)/Pd during electrolysis; cross-comparison of new elements detected in the Th-Hg-Pd-D(H) electrolytic cells / F. Celani ... [et al.]. Emergence of a high-temperature superconductivity in hydrogen cycled Pd compounds as an evidence for superstoihiometric H/D sites / A. Lipson ... [et al.]. Plasma electrolysis. Calorimetry of energy-efficient glow discharge - apparatus design and calibration / T. B. Benson and T. O. Passell. Generation of heat and products during plasma electrolysis / T. Mizuno ... [et al.]. Glow discharge. Excess heat production in Pd/D during periodic pulse discharge current in various conditions / A. B. Karabut. Beam experiments. Accelerator experiments and theoretical models for the electron screening effect in metallic environments / A. Huke, K. Czerski, and P. Heide. Evidence for a target-material dependence of the neutron-proton branching ratio in d+d reactions for deuteron energies below 20keV / A. Huke ... [et al.]. Experiments on condensed matter nuclear events in Kobe University / T. Minari ... [et al.]. Electron screening constraints for the cold fusion / K. Czerski, P. Heide, and A. Huke. Cavitation. Low mass 1.6 MHz sonofusion reactor / R. Stringham. Particle detection. Research
Progress towards an ab initio real-time treatment of warm dense matter
Baczewski, Andrew; Cangi, Attila; Hansen, Stephanie; Jensen, Daniel
2017-10-01
Time-dependent density functional theory (TDDFT) provides an accurate description of equilibrium properties of warm dense matter, such as the dynamic structure factor (Baczewski et al., Phys. Rev. Lett., 116(11), 2016). While non-equilibrium properties, such as stopping power, have also been demonstrated to be within the grasp of TDDFT, the ultrafast isochoric heating of condensed matter into the warm dense state, enabled by recent advances in XFELs, remains beyond its capabilities. In this talk, we will describe the successes of and continuing challenges for TDDFT for warm dense matter, and present progress towards a more complete ab initio treatment of isochoric x-ray heating. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the DOE's National Nuclear Security Administration under contract DE-NA0003525.
Nuclear matter and electron scattering
Energy Technology Data Exchange (ETDEWEB)
Sick, I [Dept. fuer Physik und Astronomie, Univ. Basel (Switzerland)
1998-06-01
We show that inclusive electron scattering at large momentum transfer allows a measurement of short-range properties of nuclear matter. This provides a very valuable constraint in selecting the calculations appropriate for predicting nuclear matter properties at the densities of astrophysical interest. (orig.)
Use of nuclear energy and land warming
Energy Technology Data Exchange (ETDEWEB)
Barbosa, Jose Alberto Maia; Sordi, Gian Maria Agostino Angelo; Frazao, Selma Violato; Zago, Franco Raphael do Carmo [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)], E-mail: blosspriester@gmail.com, E-mail: gmsordi@ipen.br, E-mail: selma.violato@terra.com.br, E-mail: fzago@ipen.br
2007-07-01
The world is facing an energy requirement that hardly will be covered by renewable sources actually researched. Though there is almost unanimity in the scientific community about the fact that nuclear energy is still a better option to replace oil and coal, environmental restrictions go on vigorous. And consequently, this non-consensus on nuclear energy benefits, greenhouse effect and weakening of ozone layer go on causing the land warming. In Brazil, nuclear plants are competitive and are capable to produce energy in a safe way, thus contributing to the stabilization of the national electric system and to the expansion of installed capacity and as alternative source of energy and applications for peaceful purposes, preserving the environment and planet inhabitants. (author)
Chiral thermodynamics of nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Fiorilla, Salvatore
2012-10-23
The equation of state of nuclear matter is calculated at finite temperature in the framework of in-medium chiral perturbation theory up to three-loop order. The dependence of its thermodynamic properties on the isospin-asymmetry is investigated. The chiral quark condensate is evaluated for symmetric nuclear matter. Its behaviour as a function of density and temperature sets important nuclear physics constraints for the QCD phase diagram.
Chiral thermodynamics of nuclear matter
International Nuclear Information System (INIS)
Fiorilla, Salvatore
2012-01-01
The equation of state of nuclear matter is calculated at finite temperature in the framework of in-medium chiral perturbation theory up to three-loop order. The dependence of its thermodynamic properties on the isospin-asymmetry is investigated. The chiral quark condensate is evaluated for symmetric nuclear matter. Its behaviour as a function of density and temperature sets important nuclear physics constraints for the QCD phase diagram.
Equation of state of warm condensed matter
Energy Technology Data Exchange (ETDEWEB)
Barbee, T.W., III; Young, D.A.; Rogers, F.J.
1998-03-01
Recent advances in computational condensed matter theory have yielded accurate calculations of properties of materials. These calculations have, for the most part, focused on the low temperature (T=0) limit. An accurate determination of the equation of state (EOS) at finite temperature also requires knowledge of the behavior of the electron and ion thermal pressure as a function of T. Current approaches often interpolate between calculated T=0 results and approximations valid in the high T limit. Plasma physics-based approaches are accurate in the high temperature limit, but lose accuracy below T{approximately}T{sub Fermi}. We seek to ``connect up`` these two regimes by using ab initio finite temperature methods (including linear-response[1] based phonon calculations) to derive an equation of state of condensed matter for T{<=}T{sub Fermi}. We will present theoretical results for the principal Hugoniot of shocked materials, including carbon and aluminum, up to pressures P>100 GPa and temperatures T>10{sup 4}K, and compare our results with available experimental data.
Phase transitions in nuclear matter
International Nuclear Information System (INIS)
Glendenning, N.K.
1984-11-01
The rather general circumstances under which a phase transition in hadronic matter at finite temperature to an abnormal phase in which baryon effective masses become small and in which copious baryon-antibaryon pairs appear is emphasized. A preview is also given of a soliton model of dense matter, in which at a density of about seven times nuclear density, matter ceases to be a color insulator and becomes increasingly color conducting. 22 references
Probing nuclear matter with dileptons
International Nuclear Information System (INIS)
Schroeder, L.S.
1986-06-01
Dileptons are shown to be of interest in helping probe extreme conditions of temperature and density in nuclear matter. The current state of experimental knowledge about dileptons is briefly described, and their use in upcoming experiments with light ions at CERN SPS are reviewed, including possible signatures of quark matter formation. Use of dileptons in an upcoming experiment with a new spectrometer at Berkeley is also discussed. This experiment will probe the nuclear matter equation of state at high temperature and density. 16 refs., 8 figs
Warm and cold fermionic dark matter via freeze-in
International Nuclear Information System (INIS)
Klasen, Michael; Yaguna, Carlos E.
2013-01-01
The freeze-in mechanism of dark matter production provides a simple and intriguing alternative to the WIMP paradigm. In this paper, we analyze whether freeze-in can be used to account for the dark matter in the so-called singlet fermionic model. In it, the SM is extended with only two additional fields, a singlet scalar that mixes with the Higgs boson, and the dark matter particle, a fermion assumed to be odd under a Z 2 symmetry. After numerically studying the generation of dark matter, we analyze the dependence of the relic density with respect to all the free parameters of the model. These results are then used to obtain the regions of the parameter space that are compatible with the dark matter constraint. We demonstrate that the observed dark matter abundance can be explained via freeze-in over a wide range of masses extending down to the keV range. As a result, warm and cold dark matter can be obtained in this model. It is also possible to have dark matter masses well above the unitarity bound for WIMPs
Spectral properties of nuclear matter
International Nuclear Information System (INIS)
Bozek, P
2006-01-01
We review self-consistent spectral methods for nuclear matter calculations. The in-medium T-matrix approach is conserving and thermodynamically consistent. It gives both the global and the single-particle properties the system. The T-matrix approximation allows to address the pairing phenomenon in cold nuclear matter. A generalization of nuclear matter calculations to the super.uid phase is discussed and numerical results are presented for this case. The linear response of a correlated system going beyond the Hartree-Fock+ Random-Phase-Approximation (RPA) scheme is studied. The polarization is obtained by solving a consistent Bethe-Salpeter (BS) equation for the coupling of dressed nucleons to an external field. We find that multipair contributions are important for the spin(isospin) response when the interaction is spin(isospin) dependent
Extreme states in nuclear matter
International Nuclear Information System (INIS)
Rafelski, J.; Frankfurt Univ.
1981-01-01
Theory of hot nuclear fireballs consisting of all possible finite size hadronic constituents in chemical and thermal equilibrium is presented. As a complement of this hadronic gas phase characterized by maximal temperature and energy density, the quark bag description of the hadronic fireball is considered. Preliminary calculations of temperatures and mean transverse momenta of particles emitted in high multiplicity relativistic nuclear collisions together with some considereations on the observability of quark matter are offered. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Heiselberg, H [NORDITA, Copenhagen (Denmark)
1998-06-01
The kaon energy in a nuclear medium and its dependence on kaon-nucleon and nucleon-nucleon correlations is discussed. The transition from the Lenz potential at low densities to the Hartree potential at high densities can be calculated analytically by making a Wigner-Seitz cell approximation and employing a square well potential. As the Hartree potential is less attractive than the Lenz one, kaon condensation inside cores of neutron stars appears to be less likely than previously estimated. (orig.)
Generation and characterisation of warm dense matter with intense lasers
Riley, D.
2018-01-01
In this paper I discuss the subject of warm dense matter (WDM), which, apart from being of academic interest and relevant to inertial fusion capsules, is a subject of importance to those who wish to understand the formation and structure of planetary interiors and other astrophysical bodies. I broadly outline some key properties of WDM and go on to discuss various methods of generating samples in the laboratory using large laser facilities and outline some common techniques of diagnosis. It is not intended as a comprehensive review but rather a brief outline for scientists new to the field and those with an interest but not working in the field directly.
Instability in relativistic nuclear matter
International Nuclear Information System (INIS)
Tezuka, Hirokazu.
1979-11-01
The stability of the Fermi gas state in the nuclear matter which satisfies the saturation property is considered relativistically. It is shown that the Fermi gas state is stable at very low density and at high density, but it is unstable for density fluctuation in the intermediate density region including the normal density. (author)
Incompressibility of asymmetric nuclear matter
International Nuclear Information System (INIS)
Chen, Liewen; Cai, Baojun; Shen, Chun; Ko, Cheming; Xu, Jun; Li, Baoan
2010-01-01
Using an isospin- and momentum-dependent modified Gogny (MDI) interaction, the Skyrme-Hartree-Fock (SHF) approach, and a phenomenological modified Skyrme-like (MSL) model, we have studied the incompressibility K sat (δ) of isospin asymmetric nuclear matter at its saturation density. Our results show that in the expansion of K sat (δ) in powers of isospin asymmetry δ, i.e., K sat (δ) = K 0 + K sat,2 δ 2 + K sat,4 δ 4 + O(δ 6 ), the magnitude of the 4th-order K sat,4 parameter is generally small. The 2nd-order K sat,2 parameter thus essentially characterizes the isospin dependence of the incompressibility of asymmetric nuclear matter at saturation density. Furthermore, the K sat,2 can be expressed as K sat,2 = K sym – 6L – J 0 /K 0 L in terms of the slope parameter L and the curvature parameter K sym of the symmetry energy and the third-order derivative parameter J 0 of the energy of symmetric nuclear matter at saturation density, and we find the higher order J 0 contribution to K sat,2 generally cannot be neglected. Also, we have found a linear correlation between K sym and L as well as between J 0 /K 0 and K 0 . Using these correlations together with the empirical constraints on K 0 and L, the nuclear symmetry energy E sym (ρ0) at normal nuclear density, and the nucleon effective mass, we have obtained an estimated value of K sat,2 = -370 ± 120 MeV for the 2nd-order parameter in the isospin asymmetry expansion of the incompressibility of asymmetric nuclear matter at its saturation density. (author)
Thermodynamics of neutron-rich nuclear matter
Energy Technology Data Exchange (ETDEWEB)
López, Jorge A., E-mail: jorgelopez@utep.edu [Department of Physics, University of Texas at El Paso, El Paso, Texas 79968, U.S.A (United States); Porras, Sergio Terrazas, E-mail: sterraza@uacj.mx; Gutiérrez, Araceli Rodríguez, E-mail: al104010@alumnos.uacj.mx [Universidad Autónoma de Ciudad Juárez, Ciudad Juárez, Chihuahua, México (Mexico)
2016-07-07
This manuscript presents methods to obtain properties of neutron-rich nuclear matter from classical molecular dynamics. Some of these are bulk properties of infinite nuclear matter, phase information, the Maxwell construction, spinodal lines and symmetry energy.
S-matrix approach to the equation of state of dilute nuclear matter
Indian Academy of Sciences (India)
2014-04-01
matrix framework, a method is presented to calculate the equation of state of dilute warm nuclear matter. The result is a model-independent virial series for the pressure and density that systematically includes contributions from ...
Global warming: it's not only size that matters
Hegerl, Gabriele C.
2011-09-01
impacts than temperatures that have occurred frequently due to internal climate variability. Determining when exactly temperatures enter unusual ranges may be done in many different ways (and the paper shows several, and more could be imagined), but the main result of first local emergence in low latitudes remains robust. A worrying factor is that the regions where the signal is expected to emerge first, or is already emerging are largely regions in Africa, parts of South and Central America, and the Maritime Continent; regions that are vulnerable to climate change for a variety of regions (see IPCC 2007), and regions which contribute generally little to global greenhouse gas emissions. In contrast, strong emissions of greenhouse gases occur in regions of low warming-to-variability ratio. To get even closer to the relevance of this finding for impacts, it would be interesting to place the emergence of highly unusual summer temperatures in the context not of internal variability, but in the context of variability experienced by the climate system prior to the 20th century, as, e.g. documented in palaeoclimatic reconstructions and simulated in simulations of the last millennium (see Jansen et al 2007). External forcing has moved the temperature range around more strongly for some regions and in some seasons than others. For example, while reconstructions of summer temperatures in Europe appear to show small long-term variations, winter shows deep drops in temperature in the little Ice Age and a long-term increase since then (Luterbacher et al 2004), which was at least partly caused by external forcing (Hegerl et al 2011a) and therefore 'natural variability' may be different from internal variability. A further interesting question in attempts to provide a climate-based proxy for impacts of climate change is: to what extent does the rapidity of change matter, and how does it compare to trends due to natural variability? It is reasonable to assume that fast changes impact
Meson theory and nuclear matter
International Nuclear Information System (INIS)
Skyrme, T.H.R.
1994-01-01
An attempt is made to justify the use of the concept of a 'mesic fluid' in connection with the structure of nuclear matter. A transformation is made of the usual symmetric pseudo-scalar meson theory to bring into evidence certain saturation properties, which provide a natural basis for the use of a 'self-consistent' field in the discussion of nuclear structure. Fluctuations about this semi-classical saturated state will give rise to residual interparticle forces within the nucleus, and are also briefly considered in relation to electromagnetic interactions. (author). 5 refs
Nuclear matter physics at NICA
Energy Technology Data Exchange (ETDEWEB)
Senger, P. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany)
2016-08-15
The exploration of the QCD phase diagram is one of the most exciting and challenging projects of modern nuclear physics. In particular, the investigation of nuclear matter at high baryon densities offers the opportunity to find characteristic structures such as a first-order phase transition with a region of phase coexistence and a critical endpoint. The experimental discovery of these prominent landmarks of the QCD phase diagram would be a major breakthrough in our understanding of the properties of nuclear matter. Equally important is the quantitative experimental information on the properties of hadrons in dense matter which may shed light on chiral symmetry restoration and the origin of hadron masses. Worldwide, substantial efforts at the major heavy-ion accelerators are devoted to the clarification of these fundamental questions, and new dedicated experiments are planned at future facilities like CBM at FAIR in Darmstadt and MPD at NICA/JINR in Dubna. In this article the perspectives for MPD at NICA will be discussed. (orig.)
Sonoluminescence test for equation of state in warm dense matter
International Nuclear Information System (INIS)
Ng, Siu-Fai; Barnard, J.J.; Leung, P.T.; Yu, S.S.
2008-01-01
In experiments of Single-bubble Sonoluminescence (SBSL), the bubble is heated to temperatures of a few eV in the collapse phase of the oscillation. Our hydrodynamic simulations show that the density inside the bubble can go up to the order of 1 g/cm3, and the electron density due to ionization is 1021; cm3. So the plasma coupling constant is found to be around 1 and the gas inside the bubble is in the Warm Dense Matter (WDM) regime. We simulate the light emission of SL with an optical model for thermal radiation which takes the finite opacity of the bubble into consideration. The numerical results obtained are compared to the experimental data and found to be very sensitive to the equation of state used. As theories for the equation of state, as well as the opacity data, in the WDM regime are still very uncertain, we propose that SL may be a good low-cost experimental check for the EOS and the opacity data for matter in the WDM regime
Quasiparticle interaction in nuclear matter
International Nuclear Information System (INIS)
Poggioli, R.S.; Jackson, A.D.
1975-07-01
A microscopic calculation of the quasiparticle interaction in nuclear matter is detailed. In order to take especial care of the contributions from the low momentum states, a model space is introduced. Excluded from the model space, the high momentum states are absorbed into the model interaction. Brueckner theory suggests the choice of a truncated G-matrix as a good approximation for this model interaction. A simple perturbative approach is attempted within the model space. The calculated quasiparticle interaction is consistent with experimental results. (11 tables, 14 figures)
Quantum hadrodynamic and nuclear matter
International Nuclear Information System (INIS)
Serot, B.D.
1984-01-01
The properties of infinite nuclear matter are studied in the model relativistic quantum field theory of Walecka. Neutral scalar and vector meson exchange reproduces the basic Lorentz structure of the observed nucleon-nucleon interaction, and the consequences of this structure are studied in detail. In the mean-field approximation, nuclear saturation involves a cancellation between large attractive and repulsive components in the average potential energy. The attractive scalar field decreases the nucleon mass significantly, and the strong vector repulsion implies a stiff high-density equation of state. Corrections to the mean-field approach arising from vacuum fluctuations, self-consistent nucleon exchange, and two-nucleon correlations are examined. These have a small effect on the condensed meson fields but may produce significant changes in the binding energy. Corrections to the mean-field equation of state are small at high density
Phase transition from nuclear matter to color superconducting quark matter
Energy Technology Data Exchange (ETDEWEB)
Bentz, W. E-mail: bentz@keyaki.cc.u-tokai.ac.jp; Horikawa, T.; Ishii, N.; Thomas, A.W
2003-06-02
We construct the nuclear and quark matter equations of state at zero temperature in an effective quark theory (the Nambu-Jona-Lasinio model), and discuss the phase transition between them. The nuclear matter equation of state is based on the quark-diquark description of the single nucleon, while the quark matter equation of state includes the effects of scalar diquark condensation (color superconductivity). The effect of diquark condensation on the phase transition is discussed in detail.
Nuclear interactions and hadronic matter
International Nuclear Information System (INIS)
Petrovici, Mihai; Pop, Amalia; Stoicea, Gabriel; Berceanu, Ionela; Moisa, Dorin; Petris, Mariana; Simion, Victor; Aiftimiei, Cristina; Cruceru, Ilie; Ciobanu, Mircea; Catanescu, Vasile; Caragheorgheopol; Gheorghe
2002-01-01
The new generation of heavy ion accelerators and complex experimental devices, developed in the last two decades, give access to new information concerning the dynamics of nuclear collisions and allow to obtain and study in the laboratory the nuclear matter under extreme conditions of density and temperature. Of special interest is the intermediate energy region where the reactions are dominated by the competition between the mean field and nucleon-nucleon interaction. Fundamental aspects of nuclear reaction studies are probed at different instants of a nuclear collision. One can learn about the transport properties of nuclear matter in pure nucleonic regime and understand the modification of the nucleon-nucleon cross section due to various in-medium effects: density effects, effective mass, quantum effects, three-body interactions. With increasing energy, fast particle emission associated with direct nucleon-nucleon collisions in the first steps of the reaction come into play too. At higher energy, flow measurements are crucial tests of the influence of medium effects by probing the elastic part of the nucleon-nucleon collisions. On the other side, at higher incident energies, the characteristics of the nuclear equation of state (EoS) can be studied if local thermal and chemical equilibrium turns out to be established. Understanding of the properties of the nuclear matter in extreme conditions is a fundamental goal. The EoS is also an essential ingredient in the description of the massive stars leading to supernova explosion and neutron star formation. Experimental studies of such aspects needs experimental devices of high complexity which can detect and identify event by event all products coming out from heavy ion interactions at intermediate, relativistic and ultra-relativistic energies, having as complete as possible information on their mass, charge, velocity vector. CHIMERA and FOPI are such devices for intermediate and relativistic energy, respectively. Our
Universal subhalo accretion in cold and warm dark matter cosmologies
Kubik, Bogna; Libeskind, Noam I.; Knebe, Alexander; Courtois, Hélène; Yepes, Gustavo; Gottlöber, Stefan; Hoffman, Yehuda
2017-12-01
The influence of the large-scale structure on host haloes may be studied by examining the angular infall pattern of subhaloes. In particular, since warm dark matter (WDM) and cold dark matter (CDM) cosmologies predict different abundances and internal properties for haloes at the low-mass end of the mass function, it is interesting to examine if there are differences in how these low-mass haloes are accreted. The accretion events are defined as the moment a halo becomes a substructure, namely when it crosses its host's virial radius. We quantify the cosmic web at each point by the shear tensor and examine where, with respect to its eigenvectors, such accretion events occur in ΛCDM and ΛWDM (1 keV sterile neutrino) cosmological models. We find that the CDM and WDM subhaloes are preferentially accreted along the principal axis of the shear tensor corresponding to the direction of weakest collapse. The beaming strength is modulated by the host and subhalo masses and by the redshift at which the accretion event occurs. Although strongest for the most massive hosts and subhaloes at high redshift, the preferential infall is found to be always aligned with the axis of weakest collapse, thus we say that it has universal nature. We compare the strength of beaming in the ΛWDM cosmology with the one found in the ΛCDM scenario. While the main findings remain the same, the accretion in the ΛWDM model for the most massive host haloes appears more beamed than in ΛCDM cosmology across all the redshifts.
Strongly coupled dark energy with warm dark matter vs. LCDM
Energy Technology Data Exchange (ETDEWEB)
Bonometto, S.A.; Mezzetti, M. [INAF, Osservatorio di Trieste and Trieste University, Physics Department, Astronomy Unit, Via Tiepolo 11, 34143 Trieste (Italy); Mainini, R., E-mail: bonometto@oats.inaf.it, E-mail: mezzetti@oats.inaf.it, E-mail: roberto.mainini@mib.infn.it [Physics Department G. Occhialini, Milano-Bicocca University, Piazza della Scienza 3, 20126 Milano (Italy)
2017-10-01
Cosmologies including strongly Coupled (SC) Dark Energy (DE) and Warm dark matter (SCDEW) are based on a conformally invariant (CI) attractor solution modifying the early radiative expansion. Then, aside of radiation, a kinetic field Φ and a DM component account for a stationary fraction, ∼ 1 %, of the total energy. Most SCDEW predictions are hardly distinguishable from LCDM, while SCDEW alleviates quite a few LCDM conceptual problems, as well as its difficulties to meet data below the average galaxy scale. The CI expansion begins at the end of inflation, when Φ (future DE) possibly plays a role in reheating, and ends at the Higgs scale. Afterwards, a number of viable options is open, allowing for the transition from the CI expansion to the present Universe. In this paper: (i) We show how the attractor is recovered when the spin degrees of freedom decreases. (ii) We perform a detailed comparison of CMB anisotropy and polarization spectra for SCDEW and LCDM, including tensor components, finding negligible discrepancies. (iii) Linear spectra exhibit a greater parameter dependence at large k 's, but are still consistent with data for suitable parameter choices. (iv) We also compare previous simulation results with fresh data on galaxy concentration. Finally, (v) we outline numerical difficulties at high k . This motivates a second related paper [1], where such problems are treated in a quantitative way.
Global Warming; Can Nuclear Energy Help?
International Nuclear Information System (INIS)
Knapp, V.
1998-01-01
Kyoto conference is setting the targets and limits for CO 2 emission. In the same time energy consumption is increasing, especially in developing world. If developing countries attain even a moderate fraction of energy consumption of developed countries, this will lead into large increase of total CO 2 emission, unless there is a strong increase of energy production by CO 2 non-emitting sources. Of two major candidates, solar and nuclear energy, the second is technically and economically much closer to ability to accomplish the task. The requirements for a large scale use of nuclear energy and the role of IAEA are discussed. (author)
Nuclear matter as an MIT bag crystal
International Nuclear Information System (INIS)
Zhang, Q.; Derreth, C.; Schaefer, A.; Greiner, W.
1986-01-01
An MIT bag crystal model of nuclear matter is formulated. The energy bands of the quarks are calculated as a function of the overlap between adjacent bags. A clear indication of substantial overlap is found. Accordingly, infinite nuclear matter is more similar to a quark gas than to a nucleonic structure. (author)
Quasiparticle pole strength in nuclear matter
International Nuclear Information System (INIS)
Poggioli, R.S.; Jackson, A.D.
1975-01-01
It is argued that single-particle-like behavior in nuclear matter is much less probable than Brueckner theory suggests. In particular, the quasiparticle pole strength is evaluated for nuclear matter and it is shown that, contrary to the spirit of Brueckner theory, low momentum states play a crucial role in determining the magnitude of z/sub k/sub F/. (auth)
Structure of the subsaturated nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Maruyama, Toshiki; Maruyama, Tomoyuki; Chiba, Satoshi; Iwamoto, Akira [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Niita, Koji; Oyamatsu, Kazuhiro
1998-07-01
Quantum molecular dynamics is applied to study the ground state and excited state properties of nuclear matter at subsaturation densities. The structure of nuclear matter at subsaturation density shows some exotic shapes with variation of the density. However, the structure in our result is rather irregular compared to those of previous works due to the existence of local minimum configurations. (author)
An innovative nuclear reactor as a solution to global warming
International Nuclear Information System (INIS)
Silva, Robson Silva da; Sefidvash, Farhang
2007-01-01
The problem of global warming is no longer a philosophical discussion, but it is a fact seriously threatening the future of humanity. In this paper a practical solution to the problem of global warming resulting from the fossil fuelled energy suppliers is presented. The energy conservation and alternative forms of energy such as solar, wind, and bio even though having important roles, do not satisfy the energy demand generated by an increasing world population that desires to increase its standard of living. The fission process in the nuclear reactors does not produce greenhouse gases that cause global warming. The new paradigm in nuclear energy is the future innovative reactors that meet the new standards set by the INPRO Program of the IAEA. One such a reactor is presented in this paper, namely the Fixed Bed Nuclear Reactor (FBNR) that is supported by the International Atomic Energy (IAEA) in its program of Small Reactors Without On-Site Refuelling (SRWOSR), being one of the four water cooled reactors in this program. The other three reactor concepts are PFPWR50 of Japan, BWRPB of Russia and AFPR-100 of USA. It is shown that the nuclear energy of the future is totally different than what is today in respect to safety, economics, environmental impact and proliferation. In this manner, the public perception of nuclear energy will change and its acceptability is promoted. (author)
The nuclear, an efficient tool against global warming
International Nuclear Information System (INIS)
2009-01-01
Proposing and commenting some extracts of a book by Francis Sorin (Le nucleaire et la planete), this document aims at showing that nuclear energy production is a tool to struggle against global warming because of its low carbon emission. Some assessments of this characteristic are given and discussed, as well as figures on carbon emissions in different western countries. This document also criticises the statements made by ecologists against nuclear energy. The author put nuclear energy at the same level as energy savings and renewable energies, as means to reach the desirable CO 2 saving level
Isospin dependent properties of asymmetric nuclear matter
Chowdhury, P. Roy; Basu, D. N.; Samanta, C.
2009-01-01
The density dependence of nuclear symmetry energy is determined from a systematic study of the isospin dependent bulk properties of asymmetric nuclear matter using the isoscalar and the isovector components of density dependent M3Y interaction. The incompressibility $K_\\infty$ for the symmetric nuclear matter, the isospin dependent part $K_{asy}$ of the isobaric incompressibility and the slope $L$ are all in excellent agreement with the constraints recently extracted from measured isotopic de...
Nuclear matter in neutron star crust
International Nuclear Information System (INIS)
Kido, Toshihiko; Maruyama, Toshiki; Chiba, Satoshi; Niita, Koji
2000-01-01
Properties of nuclear matter below the nuclear saturation density is analyzed by numerical simulations with the periodic boundary condition. The equation of state at these densities is softened by the formation of cluster(s) internal density of which is nearly equal to the saturation density. The structure of nuclear matter shows some exotic shapes with variation of the density. Furthermore, it is found that the symmetry parameter a sym (ρ) is not a linear function of density at low density region. (author)
Hyperon interactions in nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Dhar, Madhumita; Lenske, Horst [Institut fuer Theoretische Physik, Universitaet Giessen (Germany)
2014-07-01
Baryon-baryon interactions within the SU(3)-octet are investigated in free space and nuclear matter. A meson exchange model is used for determining the interaction. The Bethe-Salpeter equations are solved in a 3-D reduction scheme. In-medium effects have been incorporated by including a two particle Pauli projection operator in the scattering equation. The coupling of the various channels of total strangeness S=-1,-2 and conserved total charge is studied in detail. Calculations and the corresponding results are compared for using the isospin and the particle basis. Matrix elements are compared in detail, in particular discussing mixing effects of different hyperon channels. Special attention is paid to the physical thresholds. The density dependence of interaction is clearly seen in the variation of the in-medium low-energy parameters. The approach is compared to descriptions derived from chiral-EFT and other meson-exchange models e.g. the Nijmegen and the Juelich model.
Intense Ion Beams for Warm Dense Matter Physics
International Nuclear Information System (INIS)
Heimbucher, Lynn; Coleman, Joshua Eugene
2008-01-01
The Neutralized Drift Compression Experiment (NDCX) at Lawrence Berkeley National Laboratory is exploring the physical limits of compression and focusing of ion beams for heating material to warm dense matter (WDM) and fusion ignition conditions. The NDCX is a beam transport experiment with several components at a scale comparable to an inertial fusion energy driver. The NDCX is an accelerator which consists of a low-emittance ion source, high-current injector, solenoid matching section, induction bunching module, beam neutralization section, and final focusing system. The principal objectives of the experiment are to control the beam envelope, demonstrate effective neutralization of the beam space-charge, control the velocity tilt on the beam, and understand defocusing effects, field imperfections, and limitations on peak intensity such as emittance and aberrations. Target heating experiments with space-charge dominated ion beams require simultaneous longitudinal bunching and transverse focusing. A four-solenoid lattice is used to tune the beam envelope to the necessary focusing conditions before entering the induction bunching module. The induction bunching module provides a head-to-tail velocity ramp necessary to achieve peak axial compression at the desired focal plane. Downstream of the induction gap a plasma column neutralizes the beam space charge so only emittance limits the focused beam intensity. We present results of beam transport through a solenoid matching section and simultaneous focusing of a singly charged K + ion bunch at an ion energy of 0.3 MeV. The results include a qualitative comparison of experimental and calculated results after the solenoid matching section, which include time resolved current density, transverse distributions, and phase-space of the beam at different diagnostic planes. Electron cloud and gas measurements in the solenoid lattice and in the vicinity of intercepting diagnostics are also presented. Finally, comparisons of
Intense Ion Beam for Warm Dense Matter Physics
Energy Technology Data Exchange (ETDEWEB)
Coleman, Joshua Eugene [Univ. of California, Berkeley, CA (United States)
2008-01-01
The Neutralized Drift Compression Experiment (NDCX) at Lawrence Berkeley National Laboratory is exploring the physical limits of compression and focusing of ion beams for heating material to warm dense matter (WDM) and fusion ignition conditions. The NDCX is a beam transport experiment with several components at a scale comparable to an inertial fusion energy driver. The NDCX is an accelerator which consists of a low-emittance ion source, high-current injector, solenoid matching section, induction bunching module, beam neutralization section, and final focusing system. The principal objectives of the experiment are to control the beam envelope, demonstrate effective neutralization of the beam space-charge, control the velocity tilt on the beam, and understand defocusing effects, field imperfections, and limitations on peak intensity such as emittance and aberrations. Target heating experiments with space-charge dominated ion beams require simultaneous longitudinal bunching and transverse focusing. A four-solenoid lattice is used to tune the beam envelope to the necessary focusing conditions before entering the induction bunching module. The induction bunching module provides a head-to-tail velocity ramp necessary to achieve peak axial compression at the desired focal plane. Downstream of the induction gap a plasma column neutralizes the beam space charge so only emittance limits the focused beam intensity. We present results of beam transport through a solenoid matching section and simultaneous focusing of a singly charged K^{+} ion bunch at an ion energy of 0.3 MeV. The results include a qualitative comparison of experimental and calculated results after the solenoid matching section, which include time resolved current density, transverse distributions, and phase-space of the beam at different diagnostic planes. Electron cloud and gas measurements in the solenoid lattice and in the vicinity of intercepting diagnostics are also presented. Finally
A matter of degrees: A primer on global warming
International Nuclear Information System (INIS)
1993-01-01
A primer on global warming is presented in order to provide information to Canadians on making environmentally responsible decisions. The fundamentals of natural climate change, the atmospheric environment, factors that influence climate, and the greenhouse effect are explained. Global warming is then discussed with reference to paleoclimatic research, the influence of human activity on increased concentrations of greenhouse gases, and predictions of future climates. The possible impacts of global warming on Canada are described for such sectors as forests, fisheries, agriculture, sea levels, health, energy supply and demand, and the Arctic regions. The actions that citizens and governments can take in order to mitigate or adapt to global warming are then presented. A glossary and index are included. 55 refs., 17 figs
Nuclear power in the context of global warming
International Nuclear Information System (INIS)
Bodansky, D.
1989-01-01
The paper examines the extent to which nuclear power could help ameliorate the greenhouse problem. Topics discussed include: (1) How serious is the environmental threat posed by the greenhouse effect? (2) How large a part do fossil fuels play in producing greenhouse gases? (3) Is it possible to prevent or abate the anticipated global warming? (4) Can nuclear power play a significant role? (5) What overall approached might best reduce greenhouse emissions? Global cooperativeness in addressing the problem will be essential. 14 refs., 5 tabs
Fluorescence and absorption spectroscopy for warm dense matter studies and ICF plasma diagnostics
Hansen, Stephanie
2017-10-01
The burning core of an inertial confinement fusion (ICF) plasma at stagnation is surrounded by a shell of warm, dense matter whose properties are difficult both to model (due to a complex interplay of thermal, degeneracy, and strong coupling effects) and to diagnose (due to low emissivity and high opacity). We demonstrate a promising technique to study the warm dense shells of ICF plasmas based on the fluorescence emission of dopants or impurities in the shell material. This emission, which is driven by x-rays produced in the hot core, exhibits signature changes in response to compression and heating. High-resolution measurements of absorption and fluorescence features can refine our understanding of the electronic structure of material under high compression, improve our models of density-driven phenomena such as ionization potential depression and plasma polarization shifts, and help diagnose shell density, temperature, mass distribution, and residual motion in ICF plasmas at stagnation. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525. This work was supported by the U.S. Department of Energy, Office of Science Early Career Research Program, Office of Fusion Energy Sciences under FWP-14-017426.
Symmetric nuclear matter with Skyrme interaction
International Nuclear Information System (INIS)
Manisa, K.; Bicer, A.; Atav, U.
2010-01-01
The equation of state (EOS) and some properties of symmetric nuclear matter, such as the saturation density, saturation energy and incompressibility, are obtained by using Skyrme's density-dependent effective nucleon-nucleon interaction.
Skyrmions, dense matter and nuclear forces
International Nuclear Information System (INIS)
Pethick, C.J.
1984-12-01
A simple introduction to a number of properties of Skyrme's chiral soliton model of baryons is given. Some implications of the model for dense matter and for nuclear interactions are discussed. (orig.)
Pion condensation in symmetric nuclear matter
International Nuclear Information System (INIS)
Kabir, K.; Saha, S.; Nath, L.M.
1987-09-01
Using a model which is based essentially on the chiral SU(2)xSU(2) symmetry of the pion-nucleon interaction, we examine the possibility of pion condensation in symmetric nucleon matter. We find that the pion condensation is not likely to occur in symmetric nuclear matter for any finite value of the nuclear density. Consequently, no critical opalescence phenomenon is expected to be seen in the pion-nucleus interaction. (author). 20 refs
Pion condensation in symmetric nuclear matter
Kabir, K.; Saha, S.; Nath, L. M.
1988-01-01
Using a model which is based essentially on the chiral SU(2)×SU(2) symmetry of the pion-nucleon interaction, we examine the possibility of pion condensation in symmetric nucleon matter. We find that the pion condensation is not likely to occur in symmetric nuclear matter for any finite value of the nuclear density. Consequently, no critical opalescence phenomenom is expected to be seen in the pion-nucleus interaction.
Soliton matter as a model of dense nuclear matter
International Nuclear Information System (INIS)
Glendenning, N.K.
1985-01-01
We employ the hybrid soliton model of the nucleon consisting of a topological meson field and deeply bound quarks to investigate the behavior of the quarks in soliton matter as a function of density. To organize the calculation, we place the solitons on a spatial lattice. The model suggests the transition of matter from a color insulator to a color conductor above a critical density of a few times normal nuclear density. 9 references, 5 figures
Does the projected pathway to global warming targets matter?
Bärring, Lars; Strandberg, Gustav
2018-02-01
Since the ‘Paris agreement’ in 2015 there has been much focus on what a +1.5 °C or +2 °C warmer world would look like. Since the focus lies on policy relevant global warming targets, or specific warming levels (SWLs), rather than a specific point in time, projections are pooled together to form SWL ensembles based on the target temperature rather than emission scenario. This study uses an ensemble of CMIP5 global model projections to analyse how well SWL ensembles represent the stabilized climate of global warming targets. The results show that the SWL ensembles exhibit significant trends that reflect the transient nature of the RCP scenarios. These trends have clear effect on the timing and clustering of monthly cold and hot extremes, even though the effect on the temperature of the extreme months is less visible. In many regions there is a link between choice of RCP scenario used in the SWL ensemble and climate change signal in the highest monthly temperatures. In other regions there is no such clear-cut link. From this we conclude that comprehensive analyses of what prospects the different global warming targets bring about will require stabilization scenarios. Awaiting such targeted scenarios we suggest that prudent use of SWL scenarios, taking their characteristics and limitations into account, may serve as reasonable proxies in many situations.
Past and present of nuclear matter
International Nuclear Information System (INIS)
Ritter, H.G.
1994-05-01
The subject of nuclear matter is interesting for many fields of physics ranging from condensed matter to lattice QCD. Knowing its properties is important for our understanding of neutron stars, supernovae and cosmology. Experimentally, we have the most precise information on ground state nuclear matter from the mass formula and from the systematics of monopole vibrations. This gives us the ground state density, binding energy and the compression modulus k at ground state density. However, those methods can not be extended towards the regime we are most interested in, the regime of high density and high temperature. Additional information can be obtained from the observation of neutron stars and of supernova explosions. In both cases information is limited by the rare events that nature provides for us. High energy heavy ion collisions, on the other hand, allow us to perform controlled experiments in the laboratory. For a very short period in time we can create a system that lets us study nuclear matter properties. Density and temperature of the system depend on the mass of the colliding nuclei, on their energy and on the impact parameter. The system created in nuclear collisions has at best about 200 constituents not even close to infinite nuclear matter, and it lasts only for collision times of ∼ 10 -22 sec, not an ideal condition for establishing any kind of equilibrium. Extended size and thermal and chemical equilibrium, however, axe a priori conditions of nuclear matter. As a consequence we need realistic models that describe the collision dynamics and non-equilibrium effects in order to relate experimental observables to properties of nuclear matter. The study of high energy nuclear collisions started at the Bevalac. I will try to summarize the results from the Bevalac studies, the highlights of the continuing program, and extension to higher energies without claiming to be complete
Global warming---The role for nuclear power
International Nuclear Information System (INIS)
Jones, J.E. Jr.; Fulkerson, W.
1989-01-01
Nuclear power is currently making an important contribution to our energy requirements. It provides 17% of the world's electricity today --- almost 20% in the US. Reducing the emissions of carbon dioxide over the next 30 to 50 years sufficiently to address the issue of global warming can only be accomplished by a combination of much improved energy efficiency, substantial growth in use of nuclear power, and substantial growth in use of renewable energy. This paper discusses new initiatives in the major nuclear technologies (LWR, HTGR, LMR) which are emerging from a fundamental reexamination of nuclear power in response to the challenges and opportunities in the 21st century. To fulfill its role, nuclear power must gain worldwide acceptance as a viable energy option. The use of modern technology and ''passive'' safety features in next-generation nuclear power plants offers the potential to simplify their design and operation, enhance their safety, and reduce the cost of electricity. With such improvements, we believe nuclear power can regain public confidence and make a significant contribution to our energy future. 24 refs., 2 figs., 1 tab
Soil organic matter dynamics in a North America tallgrass prairie after 9 yr of experimental warming
Directory of Open Access Journals (Sweden)
X. Cheng
2011-06-01
Full Text Available The influence of global warming on soil organic matter (SOM dynamics in terrestrial ecosystems remains unclear. In this study, we combined soil fractionation with isotope analyses to examine SOM dynamics after nine years of experimental warming in a North America tallgrass prairie. Soil samples from the control plots and the warmed plots were separated into four aggregate sizes (>2000 μm, 250–2000 μm, 53–250 μm, and <53 μm, and three density fractions (free light fraction – LF, intra-aggregate particulate organic matter – iPOM, and mineral-associated organic matter – mSOM. All fractions were analyzed for their carbon (C and nitrogen (N content, and δ^{13}C and δ^{15}N values. Warming did not significantly effect soil aggregate distribution and stability but increased C_{4}-derived C input into all fractions with the greatest in LF. Warming also stimulated decay rates of C in whole soil and all aggregate sizes. C in LF turned over faster than that in iPOM in the warmed soils. The δ^{15}N values of soil fractions were more enriched in the warmed soils than those in the control, indicating that warming accelerated loss of soil N. The δ^{15}N values changed from low to high, while C:N ratios changed from high to low in the order LF, iPOM, and mSOM due to increased degree of decomposition and mineral association. Overall, warming increased the input of C_{4}-derived C by 11.6 %, which was offset by the accelerated loss of soil C. Our results suggest that global warming simultaneously stimulates C input via shift in species composition and decomposition of SOM, resulting in negligible net change in soil C.
Optical Response of Warm Dense Matter Using Real-Time Electron Dynamics
Baczewski, Andrew; Shulenburger, Luke; Desjarlais, Michael; Magyar, Rudolph
2014-03-01
The extreme temperatures and solid-like densities in warm dense matter present a unique challenge for theory, wherein neither conventional models from condensed matter nor plasma physics capture all of the relevant phenomenology. While Kubo-Greenwood DFT calculations have proven capable of reproducing optical properties of WDM, they require a significant number of virtual orbitals to reach convergence due to their perturbative nature. Real-time TDDFT presents a complementary framework with a number of computationally favorable properties, including reduced cost complexity and better scalability, and has been used to reproduce the optical response of finite and ordered extended systems. We will describe the use of Ehrenfest-TDDFT to evolve coupled electron-nuclear dynamics in WDM systems, and the subsequent evaluation of optical response functions from the real-time electron dynamics. The advantages and disadvantages of this approach will be discussed relative to the current state-of-the-art. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Security Administration under contract DE-AC04-94AL85000.
Nuclear matter as a nonlinear optical medium
International Nuclear Information System (INIS)
Hefter, E.F.; Papini, G.
1986-01-01
This paper is concerned with the question whether nuclear matter should be considered as a nonlinear optical medium. Taking, in a pragmatic way, quality and quantity of the results of well-established linear and nonlinear approaches as the main criterion, an affirmative answer is seen to be consistent with long-standing practices adhered to in nuclear physics
Nuclear matter in all its states
International Nuclear Information System (INIS)
Bonche, P.; Cugnon, J.; Babinet, R.; Mathiot, J.F.; Van Hove, L.; Buenerd, M.; Galin, J.; Lemaire, M.C.; Meyer, J.
1986-01-01
This report includes the nine lectures which have been presented at the Joliot-Curie School of Nuclear Physics in 1985. The subjects covered are the following: thermodynamic description of excited nuclei; heavy ion reactions at high energy (theoretical approach); heavy ion reactions at high energy (experimental approach); relativistic nuclear physics and quark effects in nuclei; quark matter; nuclear compressibility and its experimental determinations; hot nuclei; anti p-nucleus interaction; geant resonances at finite temperature [fr
Relativity damps OPEP in nuclear matter
International Nuclear Information System (INIS)
Banerjee, M.K.
1998-06-01
Using a relativistic Dirac-Brueckner analysis the OPEP contribution to the ground state energy of nuclear matter is studied. In the study the pion is derivative-coupled. The author finds that the role of the tensor force in the saturation mechanism is substantially reduced compared to its dominant role in a usual nonrelativistic treatment. He shows that the damping of derivative-coupled OPEP is actually due to the decrease of M * /M with increasing density. He points out that if derivative-coupled OPEP is the preferred form of nuclear effective lagrangian nonrelativistic treatment of nuclear matter is in trouble. Lacking the notion of M * it cannot replicate the damping. He suggests an examination of the feasibility of using pseudoscalar coupled πN interaction before reaching a final conclusion about nonrelativistic treatment of nuclear matter
Isospin dependent properties of asymmetric nuclear matter
Chowdhury, P. Roy; Basu, D. N.; Samanta, C.
2009-07-01
The density dependence of nuclear symmetry energy is determined from a systematic study of the isospin dependent bulk properties of asymmetric nuclear matter using the isoscalar and isovector components of the density dependent M3Y interaction. The incompressibility K∞ for the symmetric nuclear matter, the isospin dependent part Kasy of the isobaric incompressibility, and the slope L are all in excellent agreement with the constraints recently extracted from measured isotopic dependence of the giant monopole resonances in even-A Sn isotopes, from the neutron skin thickness of nuclei, and from analyses of experimental data on isospin diffusion and isotopic scaling in intermediate energy heavy-ion collisions. This work provides a fundamental basis for the understanding of nuclear matter under extreme conditions and validates the important empirical constraints obtained from recent experimental data.
The role of nuclear energy in mitigating greenhouse warming
International Nuclear Information System (INIS)
Krakowski, R.A.
1997-01-01
A behavioral, top-down, forced-equilibrium market model of long-term (∼ 2,100) global energy-economics interactions has been modified with a bottom-up nuclear energy model and used to construct consistent scenarios describing future impacts of civil nuclear materials flows in an expanding, multi-regional (13) world economy. The relative measures and tradeoffs between economic (GNP, tax impacts, productivity, etc.), environmental (greenhouse gas accumulations, waste accumulation, proliferation risk), and energy (resources, energy mixes, supply-side versus demand-side attributes) interactions that emerge from these analyses are focused herein on advancing understanding of the role that nuclear energy (and other non-carbon energy sources) might play in mitigating greenhouse warming. Two ostensibly opposing scenario drivers are investigated: (a) demand-side improvements in (non-price-induced) autonomous energy efficiency improvements; and (b) supply-side carbon-tax inducements to shift energy mixes towards reduced- or non-carbon forms. In terms of stemming greenhouse warming for minimal cost of greenhouse-gas abatement, and with the limitations of the simplified taxing schedule used, a symbiotic combination of these two approaches may offer advantages not found if each is applied separately
International Nuclear Information System (INIS)
Gauthier, Maxence
2013-01-01
The determination if the ion slowing down process (or stopping power) in warm dense matter is essential especially in the frame of inertial confinement fusion. During my thesis, our interest was driven by the modification of the charge state of ion beam emerging from warm dense matter, this quantity playing a major role in ion stopping power calculation. We took advantage of the properties exhibited by ion beams produced by high intensity short pulse lasers to study during two experiments performed at ELFIE and TITAN facilities, the charge state modification of a carbon and helium ion beams emerging from an aluminum foil isochorically heated by an energetic proton beam. In the first two chapters are presented the major challenges regarding the subject from both a theoretical and experimental point of view. Here are exposed the different simulation tools used during the thesis. The third chapter is devoted to the study of the property of laser-produced ion beams in the scope of our experiments aiming at studying the stopping power. We have studied in particular ion beams generated using lower-than-solid density targets during two experiments: helium gas jet and laser-exploded target. In the last chapter are presented the set-ups and results of the two experiments on the charge state of ion beam emerging from warm dense matter. The data we measured in solid-density cold aluminum are successfully compared with the results already obtained in conventional accelerators. (author) [fr
Global warming and oil: Can nuclear power make a difference?
International Nuclear Information System (INIS)
Bodansky, D.
1991-01-01
A responsible energy policy, for the United States and the world, must address two needs: to restrain the rate of fossil fuel consumption, and to reduce the consumption of oil. Unless the first is accomplished, the world may experience major climate changes, some perhaps disastrous, from the buildup of carbon dioxide and other greenhouse gases. Unless the second is met, we face recurring threats of economic disruption and war, due to the dangerous concentration of the world's oil resources in the Persian Gulf region. Nuclear power has long been cited as a possible answer to these needs. Mr. Bodansky takes a fresh look at the contribution nuclear power could make, in the light of our increased awareness of global warming dangers and the renewed reminders of the instabilities of oil markets. He notes, however, that the basic objections to nuclear power remain. They are well-known, stemming from concerns about reactor safety, waste disposal, nuclear proliferation, and cost. These are old but continuing controversies, involving a tangle of technical, political, social, and economic issues. If nuclear power is to be revived, these concerns clearly must be addressed. 1 fig., 7 tabs
Ambiguities about infinite nuclear matter
International Nuclear Information System (INIS)
Fabre de la Ripelle, M.
1978-01-01
Exact solutions of the harmonic-oscillator and infinite hyperspherical well are given for the ground state of a infinitely heavy (N=Z) nucleus. The density of matter is a steadily decreasing function. The kinetic energy per particle is 12% smaller than the one predicted by the Fermi sea
Magnetic properties of strongly asymmetric nuclear matter
International Nuclear Information System (INIS)
Kutschera, M.; Wojcik, W.
1988-01-01
We investigate stability of neutron matter containing a small proton admixture with respect to spin fluctuations. We establish conditions under which strongly asymmetric nuclear matter could acquire a permanent magnetization. It is shown that if the protons are localized, the system becomes unstable to spin fluctuations for arbitrarily weak proton-neutron spin interactions. For non-localized protons there exists a threshold value of the spin interaction above which the system can develop a spontaneous polarization. 12 refs., 2 figs. (author)
Charmonium formation and suppression in nuclear matter
International Nuclear Information System (INIS)
Xu Jiajun; Wang Jia; Zhuang Chao; Zhuang Pengfei
2005-01-01
The coupling Schroedinger equations describing the evolution of cc-bar states in nuclear matter are analytically and systematically solved via perturbation method, and the correlation between charmonium formation and nuclear absorption is investigated. After calculating J/Ψ and Ψ' suppression in nucleon-nucleus collisions and comparing with experiment data, it is found that the formation time effect plays an important rule in charmonium suppression, especially in Ψ' suppression. (authors)
X-ray Thomson scattering in warm dense matter at low frequencies
International Nuclear Information System (INIS)
Murillo, Michael S.
2010-01-01
The low-frequency portion of the x-ray Thomson scattering spectrum is determined by electrons that follow the slow ion motion. This ion motion is characterized by the ion-ion dynamic structure factor, which contains a wealth of information about the ions, including structure and collective modes. The frequency-integrated (diffraction) contribution is considered first. An effective dressed-particle description of warm dense matter is derived from the quantum Ornstein-Zernike equations, and this is used to identify a Yukawa model for warm dense matter. The efficacy of this approach is validated by comparing a predicted structure with data from the extreme case of a liquid metal; good agreement is found. A Thomas-Fermi model is then introduced to allow the separation of bound and free states at finite temperatures, and issues with the definition of the ionization state in warm dense matter are discussed. For applications, analytic structure factors are given on either side of the Kirkwood line. Finally, several models are constructed for describing the slow dynamics of warm dense matter. Two classes of models are introduced that both satisfy the basic sum rules. One class of models is the 'plasmon-pole'-like class, which yields the dispersion of ion-acoustic waves. Damping is then included via generalized hydrodynamics models that incorporate viscous contributions.
International Nuclear Information System (INIS)
Tauschwitz, Anna; Jacoby, Joachim; Maruhn, Joachim; Basko, Mikhail; Efremov, Vladimir; Iosilevskiy, Igor; Neumayer, Paul; Novikov, Vladimir; Tauschwitz, Andreas; Rosmej, Frank
2010-01-01
Different experimental schemes for investigation of warm dense matter produced with intense energetic ion beams are presented. The described target configurations allow direct measurements of thermophysical and transport properties of warm dense matter without hydrodynamic recalculations. The presented experiments will be realized at the current GSI synchrotron SIS-18 and the future FAIR facility in the framework of the WDM-collaboration.
Compression modes and the nuclear matter incompressibility ...
Indian Academy of Sciences (India)
We review the current status of the nuclear matter ( = and no Coulomb interaction) incompressibility coefﬁcient, , and describe the theoretical and the experimental methods used to determine from properties of compression modes in nuclei. In particular we consider the long standing problem of the conﬂicting ...
High Momentum Probes of Nuclear Matter
Energy Technology Data Exchange (ETDEWEB)
Fries, R.
2009-07-24
We discuss how the chemical composition of QCD jets is altered by final state interactions in surrounding nuclear matter. We describe this process through conversions of leading jet particles. We find that conversions lead to an enhancement of kaons at high transverse momentum in Au+Au collisions at RHIC, while their azimuthal asymmetry v{sub 2} is suppressed.
Nuclear and quark matter at high temperature
Energy Technology Data Exchange (ETDEWEB)
Biro, Tamas S. [H.A.S. Wigner Research Centre for Physics, Budapest (Hungary); Jakovac, Antal [Roland Eotvos University, Budapest (Hungary); Schram, Zsolt [University of Debrecen, Institute for Theoretical Physics, Debrecen (Hungary)
2017-03-15
We review important ideas on nuclear and quark matter description on the basis of high-temperature field theory concepts, like resummation, dimensional reduction, interaction scale separation and spectral function modification in media. Statistical and thermodynamical concepts are spotted in the light of these methods concentrating on the -partially still open- problems of the hadronization process. (orig.)
Covariant density functional theory for nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Badarch, U.
2007-07-01
The present thesis is organized as follows. In Chapter 2 we study the Nucleon-Nucleon (NN) interaction in Dirac-Brueckner (DB) approach. We start by considering the NN interaction in free-space in terms of the Bethe-Salpeter (BS) equation to the meson exchange potential model. Then we present the DB approach for nuclear matter by extending the BS equation for the in-medium NN interaction. From the solution of the three-dimensional in-medium BS equation, we derive the DB self-energies and total binding energy which are the main results of the DB approach, which we later incorporate in the field theoretical calculation of the nuclear equation of state. In Chapter 3, we introduce the basic concepts of density functional theory in the context of Quantum Hadrodynamics (QHD-I). We reach the main point of this work in Chapter 4 where we introduce the DDRH approach. In the DDRH theory, the medium dependence of the meson-nucleon vertices is expressed as functionals of the baryon field operators. Because of the complexities of the operator-valued functionals we decide to use the mean-field approximation. In Chapter 5, we contrast microscopic and phenomenological approaches to extracting density dependent meson-baryon vertices. Chapter 6 gives the results of our studies of the EOS of infinite nuclear matter in detail. Using formulas derived in Chapters 4 and 5 we calculate the properties of symmetric and asymmetric nuclear matter and pure neutron matter. (orig.)
Shock waves in relativistic nuclear matter, I
International Nuclear Information System (INIS)
Gleeson, A.M.; Raha, S.
1979-02-01
The relativistic Rankine-Hugoniot relations are developed for a 3-dimensional plane shock and a 3-dimensional oblique shock. Using these discontinuity relations together with various equations of state for nuclear matter, the temperatures and the compressibilities attainable by shock compression for a wide range of laboratory kinetic energy of the projectile are calculated. 12 references
Condensed matter studies by nuclear methods
International Nuclear Information System (INIS)
Krolas, K.; Tomala, K.
1988-01-01
The separate abstract was prepared for 1 of the papers in this volume. The remaining 13 papers dealing with the use but not with advances in the use of nuclear methods in studies of condensed matter, were considered outside the subject scope of INIS. (M.F.W.)
Covariant density functional theory for nuclear matter
International Nuclear Information System (INIS)
Badarch, U.
2007-01-01
The present thesis is organized as follows. In Chapter 2 we study the Nucleon-Nucleon (NN) interaction in Dirac-Brueckner (DB) approach. We start by considering the NN interaction in free-space in terms of the Bethe-Salpeter (BS) equation to the meson exchange potential model. Then we present the DB approach for nuclear matter by extending the BS equation for the in-medium NN interaction. From the solution of the three-dimensional in-medium BS equation, we derive the DB self-energies and total binding energy which are the main results of the DB approach, which we later incorporate in the field theoretical calculation of the nuclear equation of state. In Chapter 3, we introduce the basic concepts of density functional theory in the context of Quantum Hadrodynamics (QHD-I). We reach the main point of this work in Chapter 4 where we introduce the DDRH approach. In the DDRH theory, the medium dependence of the meson-nucleon vertices is expressed as functionals of the baryon field operators. Because of the complexities of the operator-valued functionals we decide to use the mean-field approximation. In Chapter 5, we contrast microscopic and phenomenological approaches to extracting density dependent meson-baryon vertices. Chapter 6 gives the results of our studies of the EOS of infinite nuclear matter in detail. Using formulas derived in Chapters 4 and 5 we calculate the properties of symmetric and asymmetric nuclear matter and pure neutron matter. (orig.)
Quark mobility in extended nuclear matter
International Nuclear Information System (INIS)
Sivers, D.
1988-01-01
The propagation of an energetic quark through extended nuclear matter is analyzed in terms of a simple model in which localization of color is imposed through chromoelectric flux tubes. A mobile quark in the nuclear medium creates a disturbance which affects neighboring nucleons. The model suggests that the spatial properties of the disturbance involve a competition among different dynamical mechanisms. Experimental measurements involving the target fragmentation region in deep-inelastic leptoproduction on large nuclei may help specify some of the important features of nuclear dynamics. copyright 1988 Academic Press, Inc
Nuclear and global warming issues at a deregulated electricity market
International Nuclear Information System (INIS)
Mesarovic, M.
2001-01-01
The present challenge is to develop such an energy mix that best supports industrial and societal development and improves the quality of life, while simultaneously minimizing health and environmental impacts. Although two decades ago nuclear was considered to be the energy of the future, it is often overlooked in this context and is now even being questioned in many parts of the world. But, for a world facing increased energy demand and growing concerns about global warming due to the emissions of the 'greenhouse' gasses from burning fossil fuels, nuclear power may become the first priority again, since the nuclear power plants proved to be a reliable and safe source of electricity that produce no greenhouse or acid rain gases, and have already demonstrated their economic competitiveness with alternative generating sources of electrical energy. The competitiveness of nuclear power depends essentially on capital investments which must remain low enough to secure its competitive position. However, nuclear electricity in most countries is less competitive than coal and gas, particularly so after deregulation and liberalization of electricity markets have taken place. In the European Union (EU) there are at present 151 reactor blocks and 68 more in the rest of the European continent. Nuclear power plants in EU currently generate about 35% of electricity, but with the new competitive markets, a major decline in the use of coal is compensated for by an increase in gas because of its lower carbon content, and thus almost all new power stations fully or partially use gas as fuel. However, nuclear power is expected to remain a necessary component of the EU's energy mix for the next 20 years and beyond, and in Central and Eastern Europe it is continuing its growth. While Hungary recently gave up plans to construct two more blocks in its 'Pacs' plant, the Czech government agreed to continue construction of two blocks at its 'Temelin' plant. In Rumania, the second unit of
On general features of warm dark matter with reduced relativistic gas
Hipólito-Ricaldi, W. S.; vom Marttens, R. F.; Fabris, J. C.; Shapiro, I. L.; Casarini, L.
2018-05-01
Reduced relativistic gas (RRG) is a useful approach to describe the warm dark matter (WDM) or the warmness of baryonic matter in the approximation when the interaction between the particles is irrelevant. The use of Maxwell distribution leads to the complicated equation of state of the Jüttner model of relativistic ideal gas. The RRG enables one to reproduce the same physical situation but in a much simpler form. For this reason RRG can be a useful tool for the theories with some sort of a "new Physics". On the other hand, even without the qualitatively new physical implementations, the RRG can be useful to describe the general features of WDM in a model-independent way. In this sense one can see, in particular, to which extent the cosmological manifestations of WDM may be dependent on its Particle Physics background. In the present work RRG is used as a complementary approach to derive the main observational features for the WDM in a model-independent way. The only assumption concerns a non-negligible velocity v for dark matter particles which is parameterized by the warmness parameter b. The relatively high values of b ( b^2˜ 10^{-6}) erase the radiation (photons and neutrinos) dominated epoch and cause an early warm matter domination after inflation. Furthermore, RRG approach enables one to quantify the lack of power in linear matter spectrum at small scales and in particular, reproduces the relative transfer function commonly used in context of WDM with accuracy of ≲ 1%. A warmness with b^2≲ 10^{-6} (equivalent to v≲ 300 km/s) does not alter significantly the CMB power spectrum and is in agreement with the background observational tests.
The public and nuclear matters
International Nuclear Information System (INIS)
O'Riordan, Timothy
1987-01-01
The nuclear industry has an image problem and is facing a major crisis of public confidence. The solution lies not merely in better public relations and advertising campaigns, but in a fundamental reassessment of electricity management, a comprehensive re-examination of the economics of electricity use and generation and, in all probability, a shift towards more public-friendly reactor designs. Over the next decade the industry faces two great forces: the power of public opinion and the momentum of inherent technological advance. Somehow these two elements have to be guided so that they complement each other. This article aims to show how this might be achieved. (author)
Nuclear energy the best alternative in alleviating global warming
International Nuclear Information System (INIS)
Malaki Khoshkbijari, M.; Moghadam, M. Kh.
2008-01-01
During the last century, the average temperature of the earth has abnormally increased by 0.74 c, causing concern among scientists. Some experts believe that the earth has experienced the warmest years during the last decades of 20 century, to the extent that the last 400 years have been the warmest years. The reports 2007 suggest that the hottest periods recorded occur a 1990 - 2007 which was a record high during the past 150 years. It seems that industrialization has contributed significantly to the global warming. The measurement of earth temperature dates hack to 1880 which has continued up to the present time. It is also predicted that the year 2014 would witness an unprecedented high air temperature. Moreover, scientists have expressed grave concern about the occurrence of severe droughts, scorching heat and formidable storms which are yet to strike the earth in the year 2100. According to the I nternational atomic agency , nuclear energy is by far, the best and safest production source of electricity in the future due to it's low emission rate of carbon dioxide. However , prior to making any commitment, it seem imperative to increase public awareness about the dire consequences of the continued utilization of fossil fuels. Based on research carried out by International atomic agency, nuclear energy is superior to other sources of energy in two major respects: lack of any so-called greenhouse gas emission and the utilization of uranium as the single source the energy production. The study aims at first; probing into the causes of global warming, the outcomes and ultimately provision of a way out of the problem and identifying the means to seriously cope with the problem. 5
A pulsed power hydrodynamics approach to exploring properties of warm dense matter
Energy Technology Data Exchange (ETDEWEB)
Reinovsky, Robert Emil [Los Alamos National Laboratory
2008-01-01
Pulsed Power Hydrodynamics, as an application of low-impedance, pulsed power, and high magnetic field technology developed over the last decade to study advanced hydrodynamic problems, instabilities, turbulence, and material properties, can potentially be applied to the study of the behavior and properties of warm dense matter (WDM) as well. Exploration of the properties, such as equation of state and conductivity, of warm dense matter is an emerging area of study focused on the behavior of matter at density near solid density (from 10% of solid density to a few times solid density) and modest temperatures ({approx}1-10 eV). Warm dense matter conditions can be achieved by laser or particle beam heating of very small quantities of matter on timescales short compared to the subsequent hydrodynamic expansion timescales (isochoric heating) and a vigorous community of researchers is applying these techniques using petawatt scale laser systems, but the microscopic size scale of the WDM produced in this way limits access to some physics phenomena. Pulsed power hydrodynamics techniques, either through high convergence liner compression of a large volume, modest density, low temperature plasma to densities approaching solid density or through the explosion and subsequent expansion of a conductor (wire) against a high pressure (density) gas background (isobaric expansion) techniques both offer the prospect for producing warm dense matter in macroscopic quantities. However, both techniques demand substantial energy, proper power conditioning and delivery, and an understanding of the hydrodynamic and instability processes that limit each technique. Similarly, liner compression of normal density material, perhaps using multiple reflected shocks can provide access to the challenging region above normal density -- again with the requirement of very large amounts of driving energy. In this paper we will provide an introduction to techniques that might be applied to explore this
Confinement and deconfinement of quarks in nuclear matter
International Nuclear Information System (INIS)
Baym, G.
1982-01-01
Nuclear matter at high baryon density or excitation energy is expected to undergo a transition to deconfined quark matter, a new state of matter, whose production and detection would be an exciting and basic advance in nuclear physics. These lectures summarize current understanding of quark matter and the deconfinement transition. Beginning with a review of elementary models of confinement, the basic properties of quark matter are described, estimates of the transition from hadronic to quark matter are made, and various ways one might see quark matter experimentally by production in nuclear collisions or in the form of metastable exotic nuclear objects are discussed. (author)
Fluorescence and absorption spectroscopy for warm dense matter studies and ICF plasma diagnostics
Hansen, S. B.; Harding, E. C.; Knapp, P. F.; Gomez, M. R.; Nagayama, T.; Bailey, J. E.
2018-05-01
The burning core of an inertial confinement fusion (ICF) plasma produces bright x-rays at stagnation that can directly diagnose core conditions essential for comparison to simulations and understanding fusion yields. These x-rays also backlight the surrounding shell of warm, dense matter, whose properties are critical to understanding the efficacy of the inertial confinement and global morphology. We show that the absorption and fluorescence spectra of mid-Z impurities or dopants in the warm dense shell can reveal the optical depth, temperature, and density of the shell and help constrain models of warm, dense matter. This is illustrated by the example of a high-resolution spectrum collected from an ICF plasma with a beryllium shell containing native iron impurities. Analysis of the iron K-edge provides model-independent diagnostics of the shell density (2.3 × 1024 e/cm3) and temperature (10 eV), while a 12-eV red shift in Kβ and 5-eV blue shift in the K-edge discriminate among models of warm dense matter: Both shifts are well described by a self-consistent field model based on density functional theory but are not fully consistent with isolated-atom models using ad-hoc density effects.
Asymmetric nuclear matter and neutron star properties
International Nuclear Information System (INIS)
Engvik, L.; Hjorth-Jensen, M.; Osnes, E.; Bao, G.; Oestgaard, E.
1994-06-01
Properties of neutron stars such as mass and radius, using a relativistic Dirac-Brueckner-Hartree-Fock approach, are calculated. Modern meson-exchange potential models are used to evaluate the G-matrix for asymmetric nuclear matter. For pure neutron matter the maximum mass is found to be M max ∼ 2.4M for a radius R ∼ 12 km. With a proton fraction of 30% the result is M max ∼ 2.1M for a radius R ∼ 10.5 km, close to the experimental values. The implications are discussed. 20 refs., 3 figs
Nuclear power a viable alternative in global warming context
International Nuclear Information System (INIS)
Cretu, Ileana; Balan, Iosif Bogdan; Ionila, Maria; Petra, Nicoleta Mihaela
2008-01-01
Energy sources available in the world include: coal, oil, gas, biomass, nuclear, hydroelectric, wind, solar, refuse-based, and hydrogen. In addition, fusion had been originally proposed as the long-term source. Every form of energy generation has both advantages and disadvantages. Burning fuel for energy requirements represent about 88% from the total emission of NO x and CO 2 , and about 90% from SO 2 respectively, and about 72% from suspension powder evacuated into the atmosphere. Global warming represents a real threat and is the most visible sign of the climatic changes which take place all over the world. To reduce the emission of greenhouse gases: carbon dioxide (CO 2 ), methane (CH 4 ), nitrous oxide (N 2 O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulphur hexafluoride (SF 6 ), the 'Kyoto Protocol to the United Nations framework convention on climate change' has been adopted in 1997. According to this protocol European countries must reduce their overall emissions of greenhouse gases by at least 5% below 1990 levels in the commitment period 2008 -- 2012. In this context, because the natural resources for power generation based on the fossil fuels are decreasing and their prices are rising, nuclear power has become a real alternative for classical energy sources. It is indicated by: - Fuel is inexpensive because uranium represents a very small part of nuclear power cost and uranium sediment is found on a large scale all over the world; - No greenhouse emission or acid rain effects occur during a normal operation. Nuclear power is also named 'clean energy'; - Wastes are more compact than those of any source of energy and are stored in underground and secured deposits; - Nuclear energy has a number of advantages which warrant its use as one of the many methods of fulfilling the energy-demand of the world. Even with conservation efforts, energy demand increased and will continue to increase. Using each and every one of these forms of energy
Wanted! Nuclear Data for Dark Matter Astrophysics
International Nuclear Information System (INIS)
Gondolo, P.
2014-01-01
Astronomical observations from small galaxies to the largest scales in the universe can be consistently explained by the simple idea of dark matter. The nature of dark matter is however still unknown. Empirically it cannot be any of the known particles, and many theories postulate it as a new elementary particle. Searches for dark matter particles are under way: production at high-energy accelerators, direct detection through dark matter-nucleus scattering, indirect detection through cosmic rays, gamma rays, or effects on stars. Particle dark matter searches rely on observing an excess of events above background, and a lot of controversies have arisen over the origin of observed excesses. With the new high-quality cosmic ray measurements from the AMS-02 experiment, the major uncertainty in modeling cosmic ray fluxes is in the nuclear physics cross sections for spallation and fragmentation of cosmic rays off interstellar hydrogen and helium. The understanding of direct detection backgrounds is limited by poor knowledge of cosmic ray activation in detector materials, with order of magnitude differences between simulation codes. A scarcity of data on nucleon spin densities blurs the connection between dark matter theory and experiments. What is needed, ideally, are more and better measurements of spallation cross sections relevant to cosmic rays and cosmogenic activation, and data on the nucleon spin densities in nuclei
Strange mesons in dense nuclear matter
International Nuclear Information System (INIS)
Senger, P.
2000-10-01
Experimental data on the production of kaons and antikaons in heavy ion collisions at relativistic energies are reviewed with respect to in-medium effects. The K - /K + ratios measured in nucleus-nucleus collisions are 1-2 orders of magnitude larger than in proton-proton collisions. The azimuthal angle distributions of K + mesons indicate a repulsive kaon-nucleon potential. Microscopic transport calculations consistently explain both the yields and the emission patterns of kaons and antikaons when assuming that their properties are modified in dense nuclear matter. The K + production excitation functions measured in light and heavy collision systems provide evidence for a soft nuclear equation-of-state. (orig.)
Nuclear matter and its equation of state
International Nuclear Information System (INIS)
Stock, R.
1985-11-01
We can estimate the nuclear bulk compressibility from the excitation energy of the monopole vibration mode, which represents a density oscillation about rho 0 , of extremely small magnitude (a few percent) only. A description of the monopole excitation energy systematics has been obtained by assuming a parabolic shape about rho 0 for the energy-density relation of cold nuclear matter. This implies a linear pressure response to small density changes inside nuclear matter. It enables one to define a nuclear 'sound' mode and the sound velocity turns out to be vsub(s)proportional0.2 c. All of this could be known only for small excursions from rho 0 as long as we were unable to subject nuclei to extreme stresses. The study of head-on collisions of heavy nuclei at high energy has removed this limitation. In these reactions we are reproducing under laboratory conditions the extremely violent transformations of matter occuring in the cosmic and stellar evolution. From the quark-gluon stage of the Big Bang, prior to hadronic freeze-out, to the supernova these cosmic events require an understanding of matter bulk properties over an enormous range of density, from about 10 times rho 0 down to about 10 -3 rho 0 . We will approach them through the compression-expansion-freeze-out cycle of central nucleus-nucleus collisions in the energy range from 50 MeV per projectile nucleon, corresponding to the compression barrier, upwards to 225 GeV/A (the top energy of the CERN SPS), and further into the TeV/A range by observation of events induced by cosmic ray nuclei. In this article I describe some of the results recently obtained at the BEVALAC, i.e. in the GeV/A domain. (orig./HSI)
Description of a nucleon in nuclear matter
International Nuclear Information System (INIS)
Bunatian, G.G.
1992-01-01
The nonlinear cloudy bag model, CBM, is generalized to describe a nucleon in nuclear matter at various densities ρ and temperatures T. The influence of the nuclear medium on the bag-nucleon in the framework of CBM is due to the modification of the equation describing the CBM pion field π. These changes are accounted for in the CBM by including in the CBM lagrangian the pion polarization operator π(ρ,T). The free pion propagator D is replaced in a nuclear medium by D(ρ,T). The changing of the pion field π and propagator D leads via the CBM equations to the modification of the bag size R and quark momentum p, determined simultaneously from these equations, and then to modifications of other bag-nucleon characteristics: the total energy E, r.m.s. radii, magnetic moment μ, polarizability α and so on, which all are expressed as the expectation values of the corresponding operators in the bag-nucleon state. The quantity π(ρ,T) was studied in the works whose results are used in this investigation. The nucleon size R in the nuclear matter at normal density ρ o and zero temperature decreases by 5% and the quarks momentum p also decreases, however, insignificantly, by 1-2%. On the other hand, the values of the r.m.s. radii increases by 15% for a proton and by 100% for a neutron. The author has also found that the polarizability of a nucleon in nuclear matter is roughly two times as much as in free space
Symmetric and asymmetric nuclear matter in the Thomas-Fermi model at finite temperatures
International Nuclear Information System (INIS)
Strobel, K.; Weber, F.; Weigel, M.K.
1999-01-01
The properties of warm symmetric and asymmetric nuclear matter are investigated in the frame of the Thomas-Fermi approximation using a recent modern parameterization of the effective nucleon-nucleon interaction of Myers and Swiatecki. Special attention is paid to the liquid-gas phase transition, which is of special interest in modern nuclear physics. We have determined the critical temperature, critical density and the so-called flash temperature. Furthermore, the equation of state for cold neutron star matter is calculated. (orig.)
Properties of the cloudy bag in nuclear matter
International Nuclear Information System (INIS)
Bunatyan, G.G.
1986-01-01
Because of the pion mode softening, the pion field of the clody bag in the nuclear matter increases if the nuclear density increases. This causes in its turn the decreasing of the bag size and at a sufficiently large density of the nuclear matter lead to absolute instability of the cloudy bag-nucleon, which means the transition of the nuclear matter in another nonnucleon phase
International Nuclear Information System (INIS)
Fukae, Chiyokazu
2006-01-01
Most of people think that nuclear power generation is not effective for preventing global warming. In this research, the reason why people think so was investigated with using questionnaire survey. As a result, the misunderstanding, the thermal effluent and radioactive substance etc. produced from a nuclear plant promotes global warming, has influenced on this issue. People have negative image against nuclear power in the background of this idea. This negative image is a factor to decrease the evaluation that nuclear power is useful for preventing global warming regardless of the presence of the misunderstanding. By the fear that the accident of the nuclear plant brings the environmental destruction, people evaluate that nuclear power doesn't have the capabilities for environmental preservation. Especially young people have such awareness. It is necessary to learn energy and environmental issues including the merits and demerits of nuclear power objectively in the academic training. (author)
Recognition of people with an opinion that nuclear power generation causes global warming
International Nuclear Information System (INIS)
Fukue, Chiyokazu
2004-01-01
Almost a half of the people are thinking that nuclear power generation causes global warming. We conducted a survey in order to explore the recognition and background for the thinking of people. Consequently, the existence of the right knowledge ''nuclear power generation does not discharge carbon dioxide at the time of power generation'' influenced most the idea which nuclear power generation prevents global warming. On the other hand, the misunderstanding as ''the radioactive material produced from a nuclear power plant advances global warming'' has influenced the idea considered as a cause, and it is though that this misunderstanding depend on the negative image to nuclear power generation. Moreover, many people do not recognize the mechanism of global warming, and it is thought that they confuse global warming with the other global environment problems, such as acid rain or ozone layer destruction. Therefore, it is required to spread the knowledge that nuclear power generation does not discharge carbon dioxide, and to promote the understanding that a radioactive material is not related to global warming. Furthermore, it is required to distinguish global warming from the other global environment problems, and to explain them intelligibly. (author)
A new model for nuclear matter
International Nuclear Information System (INIS)
Skyrme, T.H.R.
1994-01-01
The different values obtained for nuclear radii from electromagnetic interactions as compared with specifically nuclear interactions suggested a model of nuclear matter in which the meson field is supposed to condense into an incompressible fluid and the nucleonic sources are confined to its interior by a strong interaction between the sources and the fluid as a whole. The sources are also coupled to spin and charge fluctuations in the fluid, whose exchange leads to further internucleonic forces. It is necessary to postulate that the fluid have a comparatively low density; as a result rotational levels of the fluid are high, leading to a small probability of exchange of angular momentum (and charge coupled to it) with the sources. The values of the anomalous electrical interactions of nucleons deduced are in rough agreement with the facts. The nuclear structure indicated is a shell model embedded in the mesic fluid whose oscillations, strongly coupled to the nucleons, give rise to the collective features of nuclear structure as in the theory of Bohr and Mottelson. It is suggested that this picture of the mesic field may indicate where to look for solutions of the meson field equations. (author). 9 refs
The status and prospects of the debate upon the global warming and nuclear power
International Nuclear Information System (INIS)
Yim, C. Y.
2001-01-01
Possible climate change caused by global warming becomes one of the most serious challenges that mankind shall tackle in 21 st century. Nuclear power, which doesn't emit any greenhouse gas during the generation of electricity, is a promising solution to mitigate the global warming. However, there are still debates about the role of nuclear power related to the subjects such as safety, radioactive waste management and nuclear proliferation risk in the international climate change talks. This paper introduces on-going negotiation focused on the nuclear power and then, gives some prospects on the future negotiations. Finally the brief analysis of their impacts on domestic nuclear industry is carried out
Neutrino neutral current interactions in nuclear matter
International Nuclear Information System (INIS)
Horowitz, C.J.; Wehrberger, K.
1991-01-01
Detailed knowledge of neutrino transport properties in matter is crucial for an understanding of the evolution of supernovae and of neutron star cooling. We investigate screening of neutrino scattering from a dense degenerate gas of electrons, protons and neutrons. We take into account correlations induced by the Coulomb interactions of the electrons and protons, and the strong interactions of the protons and neutrons. Nuclear matter is described by the σω model of quantum hadrodynamics. Results are presented for typical astrophysical scenarios. The differential cross section is strongly reduced at large energy transfer, where electrons dominate, and slightly reduced for small energy transfer, where nucleons dominate. At large densities, the nucleon effective mass is considerably lower than the free mass, and the region dominated by nucleons extends to larger energy transfer than for free nucleons. (orig.)
Strangeness in hot and dense nuclear matter
International Nuclear Information System (INIS)
Nappi, E.
2009-01-01
Ultra-relativistic heavy-ion collisions are believed to provide the extreme conditions of energy densities able to lead to a transition to a short-lived state, called Quark-Gluon Plasma (QGP), where the quarks are no longer bound inside hadrons. The studies performed so far, formerly at SPS (CERN) and later at RHIC (BNL) allowed to achieve a multitude of crucial results consistent with the hypothesis that a new phase of the QCD matter has been indeed created. However, the emerging picture is that of the formation of a strongly interacting medium with negligibly small viscosity, a perfect liquid, rather than the ideal perturbative QCD parton-gas predicted by most theorists. The head-on collision between lead nuclei at the unprecedented energies of the forthcoming Large Hadron Collider (LHC) at CERN, due to start in 2008, will allow to measure the properties of compressed and excited nuclear matter at even higher initial densities and temperatures, far above the predicted QCD phase transition point. The longer duration of the quark-gluon plasma phase and the much more abundant production of hard probes, which depend much less on details of the later hadronic phase, will likely provide a consistent and uncontroversial experimental evidence of the QGP formation. Among the signals what witness the charge in the nature of the state of nuclear matter, the chemical equilibrium value of the strangeness plays a key role since it is directly sensitive to the matter properties and provides information on the link between the partonic and the hadronic phases. The aim of this course is to overview the underlying goals, the current status and the prospect of the physics of the nucleus-nucleus collisions at ultrarelativistic energies. Among the experimental methods adopted to investigate the challenging signatures of the QGP formation, emphasis on those related to the strangeness flavour will be given.
Kaon dynamics in dense nuclear matter
International Nuclear Information System (INIS)
David, Ch.
1998-01-01
In this thesis a list of cross sections concerning the kaons and antikaons production, has been presented. A new method for the parametrisation of particles rescattering cross sections, based on the neural networks has been developed. Because of the influence of the nuclear matter on kaons properties, the effect of the optical potential parameters has been studied. In particular a term has been added to the vector part of this potential to determine the relative importance of this part compared to the scalar part. A new parametrisation of the resonance lifetime has been proposed. (A.L.B.)
Pion condensation in symmetric nuclear matter
International Nuclear Information System (INIS)
Shamsunnahar, T.; Saha, S.; Kabir, K.; Nath, L.M.
1991-01-01
We have investigated the possibility of pion condensation in symmetric nuclear matter using a model of pion-nucleon interaction based essentially on chiral SU(2) x SU(2) symmetry. We have found that pion condensation is not possible for any finite value of the density. Consequently, no critical opalescence phenomenon is likely to be seen in pion-nucleus scattering nor is it likely to be possible to explain the EMC effect in terms of an increased number of pions in the nucleus. (author)
History of the nuclear matter safety and control law
International Nuclear Information System (INIS)
Dean, G.
1994-01-01
In this text we give the history of the law creation on the control and safety of nuclear matter. Initially based on the CEA regulation single owner of nuclear matter, the development of nuclear energy has conducted the French government to edict law in relation with IAEA and Euratom recommendations
Pseudo-Goldstone modes in isospin-asymmetric nuclear matter
International Nuclear Information System (INIS)
Cohen, T.D.; Broniowski, W.
1995-01-01
The authors analyze the chiral limit in dense isospin-asymmetric nuclear matter. It is shown that the pseudo-Goldstone modes in this system are qualitatively different from the case of isospin-symmetric matter
Hadronic spectral functions in nuclear matter
International Nuclear Information System (INIS)
Post, M.; Leupold, S.; Mosel, U.
2004-01-01
We study the in-medium properties of mesons (π,η,ρ) and baryon resonances in cold nuclear matter within a coupled-channel analysis. The meson self energies are generated by particle-hole excitations. Thus multi-peak spectra are obtained for the mesonic spectral functions. In turn this leads to medium-modifications of the baryon resonances. Special care is taken to respect the analyticity of the spectral functions and to take into account effects from short-range correlations both for positive and negative parity states. Our model produces sensible results for pion and Δ dynamics in nuclear matter. We find a strong interplay of the ρ meson and the D 13 (1520), which moves spectral strength of the ρ spectrum to smaller invariant masses and leads to a broadening of the baryon resonance. The optical potential for the η meson resulting from our model is rather attractive whereas the in-medium properties modifications of the S 11 (1535) are found to be quite small
Sound modes in hot nuclear matter
International Nuclear Information System (INIS)
Kolomietz, V. M.; Shlomo, S.
2001-01-01
The propagation of the isoscalar and isovector sound modes in a hot nuclear matter is considered. The approach is based on the collisional kinetic theory and takes into account the temperature and memory effects. It is shown that the sound velocity and the attenuation coefficient are significantly influenced by the Fermi surface distortion (FSD). The corresponding influence is much stronger for the isoscalar mode than for the isovector one. The memory effects cause a nonmonotonous behavior of the attenuation coefficient as a function of the relaxation time leading to a zero-to-first sound transition with increasing temperature. The mixing of both the isoscalar and the isovector sound modes in an asymmetric nuclear matter is evaluated. The condition for the bulk instability and the instability growth rate in the presence of the memory effects is studied. It is shown that both the FSD and the relaxation processes lead to a shift of the maximum of the instability growth rate to the longer-wavelength region
D mesons in asymmetric nuclear matter
International Nuclear Information System (INIS)
Mishra, Amruta; Mazumdar, Arindam
2009-01-01
We calculate the in-medium D and D meson masses in isospin-asymmetric nuclear matter in an effective chiral model. The D and D mass modifications arising from their interactions with the nucleons and the scalar mesons in the effective hadronic model are seen to be appreciable at high densities and have a strong isospin dependence. These mass modifications can open the channels of the decay of the charmonium states (Ψ ' ,χ c ,J/Ψ) to DD pairs in dense hadronic matter. The isospin asymmetry in the doublet D=(D 0 ,D + ) is seen to be particularly appreciable at high densities and should show in observables such as their production and flow in asymmetric heavy-ion collisions in the compressed baryonic matter experiments in the future facility of FAIR, GSI. The results of the present work are compared to calculations of the D(D) in-medium masses in the literature using the QCD sum rule approach, quark meson coupling model, and coupled channel approach as well as to those from studies of quarkonium dissociation using heavy-quark potentials from lattice QCD at finite temperatures
Big Bang synthesis of nuclear dark matter
International Nuclear Information System (INIS)
Hardy, Edward; Lasenby, Robert; March-Russell, John; West, Stephen M.
2015-01-01
We investigate the physics of dark matter models featuring composite bound states carrying a large conserved dark “nucleon” number. The properties of sufficiently large dark nuclei may obey simple scaling laws, and we find that this scaling can determine the number distribution of nuclei resulting from Big Bang Dark Nucleosynthesis. For plausible models of asymmetric dark matter, dark nuclei of large nucleon number, e.g. ≳10 8 , may be synthesised, with the number distribution taking one of two characteristic forms. If small-nucleon-number fusions are sufficiently fast, the distribution of dark nuclei takes on a logarithmically-peaked, universal form, independent of many details of the initial conditions and small-number interactions. In the case of a substantial bottleneck to nucleosynthesis for small dark nuclei, we find the surprising result that even larger nuclei, with size ≫10 8 , are often finally synthesised, again with a simple number distribution. We briefly discuss the constraints arising from the novel dark sector energetics, and the extended set of (often parametrically light) dark sector states that can occur in complete models of nuclear dark matter. The physics of the coherent enhancement of direct detection signals, the nature of the accompanying dark-sector form factors, and the possible modifications to astrophysical processes are discussed in detail in a companion paper.
Current Issues in Finite-T Density-Functional Theory and Warm-Correlated Matter †
Directory of Open Access Journals (Sweden)
M. W. C. Dharma-wardana
2016-03-01
Full Text Available Finite-temperature density functional theory (DFT has become of topical interest, partly due to the increasing ability to create novel states of warm-correlated matter (WCM.Warm-dense matter (WDM, ultra-fast matter (UFM, and high-energy density matter (HEDM may all be regarded as subclasses of WCM. Strong electron-electron, ion-ion and electron-ion correlation effects and partial degeneracies are found in these systems where the electron temperature Te is comparable to the electron Fermi energy EF. Thus, many electrons are in continuum states which are partially occupied. The ion subsystem may be solid, liquid or plasma, with many states of ionization with ionic charge Zj. Quasi-equilibria with the ion temperature Ti ≠ Te are common. The ion subsystem in WCM can no longer be treated as a passive “external potential”, as is customary in T = 0 DFT dominated by solid-state theory or quantum chemistry. Many basic questions arise in trying to implement DFT for WCM. Hohenberg-Kohn-Mermin theory can be adapted for treating these systems if suitable finite-T exchange-correlation (XC functionals can be constructed. They are functionals of both the one-body electron density ne and the one-body ion densities ρj. Here, j counts many species of nuclei or charge states. A method of approximately but accurately mapping the quantum electrons to a classical Coulomb gas enables one to treat electron-ion systems entirely classically at any temperature and arbitrary spin polarization, using exchange-correlation effects calculated in situ, directly from the pair-distribution functions. This eliminates the need for any XC-functionals. This classical map has been used to calculate the equation of state of WDM systems, and construct a finite-T XC functional that is found to be in close agreement with recent quantum path-integral simulation data. In this review, current developments and concerns in finite-T DFT, especially in the context of non-relativistic warm
Vector Mesons in Cold Nuclear Matter
International Nuclear Information System (INIS)
Rodrigues, Tulio E; Arruda-Neto, Joāo Dias de Toledo
2013-01-01
The attenuation of vector mesons in cold nuclear matter is studied through the mechanism of incoherent photoproduction off complex nuclei. The latter is described via the time-dependent multi-collisional Monte Carlo (MCMC) intranuclear cascade model. The results for the transparency ratios of ω mesons reproduce previous measurements of CB-ELSA/TAPS with an inelastic ωN cross section around 40 mb for ρ ω ∼ 1.1 GeV/c. The corresponding in-medium width (nuclear rest frame) is extracted dinamically from the algorithm and depends on the average nuclear density p N and target nucleus: ∼ 49.2 MeV/c 2 for carbon (p N ≈ 0.114 far −3 ) and ∼ 77.3 MeV/c 2 for lead (p N ≈ 0.137 far −−3 ). The calculations fail to reproduce the huge absorption observed at JLab assuming the same inelastic cross section and the discrepancy between the two experiments remains a challenge.
Why do they think nuclear power is origin of global warming effect?
International Nuclear Information System (INIS)
Fukae, Chiyokazu
2005-01-01
A questionnaire on nuclear power was conducted on 1500 adults in Kansai area, Japan, from October 9 to November 9, 2003. The recovery ratio was 71.0%. The results showed that 34% of them thought the nuclear power was protection of the global warming effect and 35% it was origin of the effect. It was analyzed by the logistic regression analysis method on whether the nuclear power was protection of global warming effect or not. About 43% of them recognized the nuclear power contributed to control carbon dioxide emission, and the mechanism of global warming effect. However, 35% of them did not recognize the mechanism and thought radioactive materials emission gave bad effects on the global environment. To make recognize the nuclear power is a good power source for protection of the global warming effect, the amount of reduction of carbon dioxide emission by nuclear power had to be shown. It is the shortest way for solution of the global warming problem to prove worthy of nuclear power's trust by safety and stable operation. (S.Y.)
Hirschegg '95: Dynamical properties of hadrons in nuclear matter. Proceedings
International Nuclear Information System (INIS)
Feldmeier, H.; Noerenberg, W.
1995-01-01
The following topics were dealt with: Chiral symmetry, chiral condensates, in-medium effective chiral Lagrangians, Δ's in nuclei, nonperturbative QCD, electron scattering from nuclear matter, nuclear shadowing, QCD sum rules, deconfinement, ultrarelativistic heavy ion collisions, nuclear dimuon and electron pair production, photoproduction from nuclei, subthreshold K + production, kaon polarization in nuclear matter, charged pion production in relativistic heavy ion collisions, the Nambu-Jona-Lasinio model, the SU(3) L xSU(3) R sigma model, nonequilibrium dense nuclear matter, pion pair production at finite temperature. (HSI)
Nuclear matter from chiral effective field theory
International Nuclear Information System (INIS)
Drischler, Christian
2017-01-01
Nuclear matter is an ideal theoretical system that provides key insights into the physics of different length scales. While recent ab initio calculations of medium-mass to heavy nuclei have demonstrated that realistic saturation properties in infinite matter are crucial for reproducing experimental binding energies and charge radii, the nuclear-matter equation of state allows tight constraints on key quantities of neutron stars. In the present thesis we take advantage of both aspects. Chiral effective field theory (EFT) with pion and nucleon degrees of freedom has become the modern low-energy approach to nuclear forces based on the symmetries of quantum chromodynamics, the fundamental theory of strong interactions. The systematic chiral expansion enables improvable calculations associated with theoretical uncertainty estimates. In recent years, chiral many-body forces were derived up to high orders, allowing consistent calculations including all many-body contributions at next-to-next-to-next-to-leading order (N 3 LO). Many further advances have driven the construction of novel chiral potentials with different regularization schemes. Here, we develop advanced methods for microscopic calculations of the equation of state of homogeneous nuclear matter with arbitrary proton-to-neutron ratio at zero temperature. Specifically, we push the limits of many-body perturbation theory (MBPT) considerations to high orders in the chiral and in the many-body expansion. To address the challenging inclusion of three-body forces, we introduce a new partial-wave method for normal ordering that generalizes the treatment of these contributions. We show improved predictions for the neutron-matter equation of state with consistent N 3 LO nucleon-nucleon (NN) plus three-nucleon (3N) potentials using MBPT up to third order and self-consistent Green's function theory. The latter also provides nonperturbative benchmarks for the many-body convergence. In addition, we extend the normal
Nuclear matter from chiral effective field theory
Energy Technology Data Exchange (ETDEWEB)
Drischler, Christian
2017-11-15
Nuclear matter is an ideal theoretical system that provides key insights into the physics of different length scales. While recent ab initio calculations of medium-mass to heavy nuclei have demonstrated that realistic saturation properties in infinite matter are crucial for reproducing experimental binding energies and charge radii, the nuclear-matter equation of state allows tight constraints on key quantities of neutron stars. In the present thesis we take advantage of both aspects. Chiral effective field theory (EFT) with pion and nucleon degrees of freedom has become the modern low-energy approach to nuclear forces based on the symmetries of quantum chromodynamics, the fundamental theory of strong interactions. The systematic chiral expansion enables improvable calculations associated with theoretical uncertainty estimates. In recent years, chiral many-body forces were derived up to high orders, allowing consistent calculations including all many-body contributions at next-to-next-to-next-to-leading order (N{sup 3}LO). Many further advances have driven the construction of novel chiral potentials with different regularization schemes. Here, we develop advanced methods for microscopic calculations of the equation of state of homogeneous nuclear matter with arbitrary proton-to-neutron ratio at zero temperature. Specifically, we push the limits of many-body perturbation theory (MBPT) considerations to high orders in the chiral and in the many-body expansion. To address the challenging inclusion of three-body forces, we introduce a new partial-wave method for normal ordering that generalizes the treatment of these contributions. We show improved predictions for the neutron-matter equation of state with consistent N{sup 3}LO nucleon-nucleon (NN) plus three-nucleon (3N) potentials using MBPT up to third order and self-consistent Green's function theory. The latter also provides nonperturbative benchmarks for the many-body convergence. In addition, we extend the
Blok, Daan; Faucherre, Samuel; Banyasz, Imre; Rinnan, Riikka; Michelsen, Anders; Elberling, Bo
2017-12-13
Tundra regions are projected to warm rapidly during the coming decades. The tundra biome holds the largest terrestrial carbon pool, largely contained in frozen permafrost soils. With warming, these permafrost soils may thaw and become available for microbial decomposition, potentially providing a positive feedback to global warming. Warming may directly stimulate microbial metabolism but may also indirectly stimulate organic matter turnover through increased plant productivity by soil priming from root exudates and accelerated litter turnover rates. Here, we assess the impacts of experimental warming on turnover rates of leaf litter, active layer soil and thawed permafrost sediment in two high-arctic tundra heath sites in NE-Greenland, either dominated by evergreen or deciduous shrubs. We incubated shrub leaf litter on the surface of control and warmed plots for 1 and 2 years. Active layer soil was collected from the plots to assess the effects of 8 years of field warming on soil carbon stocks. Finally, we incubated open cores filled with newly thawed permafrost soil for 2 years in the active layer of the same plots. After field incubation, we measured basal respiration rates of recovered thawed permafrost cores in the lab. Warming significantly reduced litter mass loss by 26% after 1 year incubation, but differences in litter mass loss among treatments disappeared after 2 years incubation. Warming also reduced litter nitrogen mineralization and decreased the litter carbon to nitrogen ratio. Active layer soil carbon stocks were reduced 15% by warming, while soil dissolved nitrogen was reduced by half in warmed plots. Warming had a positive legacy effect on carbon turnover rates in thawed permafrost cores, with 10% higher respiration rates measured in cores from warmed plots. These results demonstrate that warming may have contrasting effects on above- and belowground tundra carbon turnover, possibly governed by microbial resource availability. © 2017 John
Too hot to handle? Analytic solutions for massive neutrino or warm dark matter cosmologies
Slepian, Zachary; Portillo, Stephen K. N.
2018-05-01
We obtain novel closed-form solutions to the Friedmann equation for cosmological models containing a component whose equation of state is that of radiation (w = 1/3) at early times and that of cold pressureless matter (w = 0) at late times. The equation of state smoothly transitions from the early to late-time behavior and exactly describes the evolution of a species with a Dirac Delta function distribution in momentum magnitudes |p_0| (i.e. all particles have the same |p_0|). Such a component, here termed "hot matter", is an approximate model for both neutrinos and warm dark matter. We consider it alone and in combination with cold matter and with radiation, also obtaining closed-form solutions for the growth of super-horizon perturbations in each case. The idealized model recovers t(a) to better than 1.5% accuracy for all a relative to a Fermi-Dirac distribution (as describes neutrinos). We conclude by adding the second moment of the distribution to our exact solution and then generalizing to include all moments of an arbitrary momentum distribution in a closed-form solution.
Simulation study for the nuclear matter below the saturation density
International Nuclear Information System (INIS)
Kido, Toshihiko; Maruyama, Toshiki; Chiba, Satoshi; Niita, Koji
1999-01-01
The infinite nuclear matter that consists of numerous protons and neutrons is described by using periodic boundary conditions. The motion of each nucleon in the fundamental cell is decided by a Molecular Dynamics. The ground states or the excited states of the nuclear matter are simulated. (author)
On the thermal properties of polarized nuclear matter
International Nuclear Information System (INIS)
Hassan, M.Y.M.; Montasser, S.S.; Ramadan, S.
1979-08-01
The thermal properties of polarized nuclear matter are calculated using Skyrme III interaction modified by Dabrowski for polarized nuclear matter. The temperature dependence of the volume, isospin, spin and spin isospin pressure and energies are determined. The temperature, isospin, spin and spin isospin dependence of the equilibrium Fermi momentum is also discussed. (author)
On the spin saturation and thermal properties of nuclear matter
International Nuclear Information System (INIS)
Hassan, M.Y.M.; Ramadan, S.
1983-12-01
The binding energy and the incompressibility of nuclear matter with degree of spin saturation D is calculated using the Skyrme interaction and two forms of a velocity dependent effective potential. The effect of the degree of spin saturation D on the thermal properties of nuclear matter is also discussed. It is found that generally the pressure decreases with increasing D. (author)
Phase transitions in nuclear matter and consequences for neutron stars
International Nuclear Information System (INIS)
Kaempfer, B.
1983-04-01
Estimates of the minimal bombarding energy necessary to reach the quark gluon phase in heavy ion collisions are presented within a hydrodynamical scenario. Further, the consequences of first-order phase transitions from nuclear/neutron matter to pion-condensed matter or quark matter are discussed for neutron stars. (author)
Nuclear Energy is the Answer to Cope with the Lack of Energy and Global Warming
International Nuclear Information System (INIS)
Wisnu Arya Wardhana
2009-01-01
This paper of nuclear energy is the answer to cope with the lack of energy and global warming based on the analysis of energy demand which is increasing rapidly, meanwhile the energy reserve is limited and decreased. Mostly world′s energy is generated by fossil fuel energy, mainly oil and coal. Fossil fuel energy and industrial activities produce green house gases (GHG) such as : COx, CH 4 , N 2 O, and CFC which cause of global warming. Global warming gives bad impact to environment and to human being. Every country in the world needs sufficient energy, but the energy resources is limited and decreased. The answer for this solution must be an energy source which does not produce green house gases. Why nuclear energy is chosen to cope with the lack of energy and global warming will be explained briefly in this paper. (author)
A fermionic molecular dynamics technique to model nuclear matter
International Nuclear Information System (INIS)
Vantournhout, K.; Jachowicz, N.; Ryckebusch, J.
2009-01-01
Full text: At sub-nuclear densities of about 10 14 g/cm 3 , nuclear matter arranges itself in a variety of complex shapes. This can be the case in the crust of neutron stars and in core-collapse supernovae. These slab like and rod like structures, designated as nuclear pasta, have been modelled with classical molecular dynamics techniques. We present a technique, based on fermionic molecular dynamics, to model nuclear matter at sub-nuclear densities in a semi classical framework. The dynamical evolution of an antisymmetric ground state is described making the assumption of periodic boundary conditions. Adding the concepts of antisymmetry, spin and probability distributions to classical molecular dynamics, brings the dynamical description of nuclear matter to a quantum mechanical level. Applications of this model vary from investigation of macroscopic observables and the equation of state to the study of fundamental interactions on the microscopic structure of the matter. (author)
Nucleons, Nuclear Matter and Quark Matter: A unified NJL approach
Energy Technology Data Exchange (ETDEWEB)
S. Lawley; W. Bentz; A.W. Thomas
2006-02-10
We use an effective quark model to describe both hadronic matter and deconfined quark matter. By calculating the equations of state and the corresponding neutron star properties, we show that the internal properties of the nucleon have important implications for the properties of these systems.
Nucleons, nuclear matter and quark matter: a unified NJL approach
Energy Technology Data Exchange (ETDEWEB)
Lawley, S [Special Research Centre for the Subatomic Structure of Matter, University of Adelaide, Adelaide SA 5005 (Australia); Bentz, W [Department of Physics, School of Science, Tokai University Hiratsuka-shi, Kanagawa 259-1292 (Japan); Thomas, A W [Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)
2006-05-01
We use an effective quark model to describe both hadronic matter and deconfined quark matter. By calculating the equations of state and the corresponding neutron star properties, we show that the internal properties of the nucleon have important implications for the properties of these systems.
Asymmetric nuclear matter in a modified quark meson coupling model
International Nuclear Information System (INIS)
Mishra, R.N.; Sahoo, H.S.; Panda, P.K.; Barik, N.
2014-01-01
In an earlier attempt we have successfully used this model in developing the nuclear equation of state and analysed various other bulk properties of symmetric nuclear matter with the dependence of quark masses. In the present work we want to apply the model to analyze asymmetric nuclear matter with the variation of the asymmetry parameter y p as well as analyze the effects of symmetry energy and the slope of the symmetry energy L
Can sterile neutrinos be ruled out as warm dark matter candidates?
Viel, M; Hähnelt, M G; Matarrese, S; Riotto, Antonio; Viel, Matteo; Lesgourgues, Julien; Haehnelt, Martin G.; Matarrese, Sabino; Riotto, Antonio
2006-01-01
We present constraints on the mass of Warm Dark Matter (WDM) particles from a combined analysis of the matter power spectrum inferred from the SDSS (Sloan Digital Sky Survey) Lyman-alpha flux power spectrum at 2.2 10 keV (2 sigma) if the WDM consists of sterile neutrinos and m_wdm > 2 keV (2 sigma) for early decoupled thermal relics. These results significantly improve our previous estimates based on high-resolution Lyman-alpha forest data at lower redshift. Our new limits are consistent with those of Seljak et al. (2006), albeit ~ 30 % smaller. If we combine this bound with the constraint derived from X-ray flux observations in the Coma cluster periphery (Boyarsky et al.), we find that the only allowed sterile neutrino mass is ~ 10 keV (in the standard production scenario with non-resonant neutrino oscillations). Adding constraints based on X-ray fluxes from the Andromeda galaxy or the Milky Way, we find that dark matter particles cannot be sterile neutrinos, unless the latter are produced by resonant oscill...
Antikaons in infinite nuclear matter and nuclei
International Nuclear Information System (INIS)
Moeller, M.
2007-01-01
In this work we studied the properties of antikaons and hyperons in infinite cold nuclear matter. The in-medium antikaon-nucleon scattering amplitude and self-energy has been calculated within a covariant many-body framework in the first part. Nuclear saturation effects have been taken into account in terms of scalar and vector nucleon mean-fields. In the second part of the work we introduced a non-local method for the description of kaonic atoms. The many-body approach of anti KN scattering can be tested by the application to kaonic atoms. A self-consistent and covariant many-body approach has been used for the determination of the antikaon spectral function and anti KN scattering amplitudes. It considers s-, p- and d-waves and the application of an in-medium projector algebra accounts for proper mixing of partial waves in the medium. The on-shell reduction scheme is also implemented by means of the projector algebra. The Bethe-Salpeter equation has been rewritten, so that the free-space anti KN scattering can be used as the interaction kernel for the in-medium scattering equation. The latter free-space scattering is based on a realistic coupled-channel dynamics and chiral SU(3) Lagrangian. Our many-body approach is generalized for the presence of large scalar and vector nucleon mean-fields. It is supplemented by an improved renormalization scheme, that systematically avoids the occurrence of medium-induced power-divergent structures and kinematical singularities. A modified projector basis has been introduced, that allows for a convenient inclusion of nucleon mean-fields. The description of the results in terms of the 'physical' basis is done with the help of a recoupling scheme based on the projector algebra properties. (orig.)
Coherent scattering of neutrinos by 'nuclear pasta' in dense matter
International Nuclear Information System (INIS)
Sonoda, Hidetaka
2007-01-01
We examine coherent scattering cross section of neutrino and nucleon systems via weak-neutral current at subnuclear densities, which will be important in supernova cores. Below melting density and temparature of nuclei, nuclear shape becomes rodlike and slablike; this is called nuclear 'pasta'. Transition of structure will greatly influence coherent effects which can not easily be predicted. We calculate static structure factor of nuclear matter using data of several nuclear models, and discuss the effects of existence of nuclear pasta on neutrino opacity in hot dense matter
Accelerator and Ion Beam Tradeoffs for Studies of Warm Dense Matter
International Nuclear Information System (INIS)
Barnard, J.J.; Briggs, R.J.; Callahan, D.A.; Davidson, R.C.; Friedman, A.; Grisham, L.; Lee, E.P.; Lee, R.W.; Logan, B.G.; Olson, C.L.; Rose, D.V.; Santhanam, P.; Sessler, A.M.; Staples, J.W.; Tabak, M.; Welch, D.R.; Wurtele, J.S.; Yu, S.S.
2006-01-01
One approach for heating a target to ''Warm Dense Matter'' conditions (similar, for example, to the interiors of giant planets or certain stages in inertial confinement fusion targets), is to use intense ion beams as the heating source (see refs.[6] and [7] and references therein for motivation and accelerator concepts). By consideration of ion beam phase-space constraints, both at the injector, and at the final focus, and consideration of simple equations of state and relations for ion stopping, approximate conditions at the target foil may be calculated. Thus, target temperature and pressure may be calculated as a function of ion mass, ion energy, pulse duration, velocity tilt, and other accelerator parameters. We connect some of these basic parameters to help search the extensive parameter space including ion mass, ion energy, total charge in beam pulse, beam emittance, target thickness and density
Dark Radiation or Warm Dark Matter from long lived particle decays in the light of Planck
International Nuclear Information System (INIS)
Di Bari, Pasquale; King, Stephen F.; Merle, Alexander
2013-01-01
Although Planck data supports the standard ΛCDM model, it still allows for the presence of Dark Radiation corresponding up to about half an extra standard neutrino species. We propose a scenario for obtaining a fractional “effective neutrino species” from a thermally produced particle which decays into a much lighter stable relic plus standard fermions. At lifetimes much longer than ∼1 s, both the relic particles and the non-thermal neutrino component contribute to Dark Radiation. By increasing the stable-to-unstable particle mass ratio, the relic particle no longer acts as Dark Radiation but instead becomes a candidate for Warm Dark Matter with mass O(1 keV–100 GeV). In both cases it is possible to address the lithium problem
Input energy measurement toward warm dense matter generation using intense pulsed power generator
Hayashi, R.; Ito, T.; Ishitani, T.; Tamura, F.; Kudo, T.; Takakura, N.; Kashine, K.; Takahashi, K.; Sasaki, T.; Kikuchi, T.; Harada, Nob.; Jiang, W.; Tokuchi, A.
2016-05-01
In order to investigate properties of warm dense matter (WDM) in inertial confinement fusion (ICF), evaluation method for the WDM with isochoric heating on the implosion time-scale using an intense pulsed power generator ETIGO-II (∼1 TW, ∼50 ns) has been considered. In this study, the history of input energy into the sample is measured from the voltage and the current waveforms. To achieve isochoric heating, a foamed aluminum with pore sizes 600 μm and with 90% porosity was packed into a hollow glass capillary (ø 5 mm × 10 mm). The temperature of the sample is calculated from the numerical calculation using the measured input power. According to the above measurements, the input energy into a sample and the achievable temperature are estimated to be 300 J and 6000 K. It indicates that the WDM state is generated using the proposed method with ICF implosion time-scale.
Accelerator and Ion Beam Tradeoffs for Studies of Warm Dense Matter
Barnard, John J; Callahan, Debra; Davidson, Ronald C; Friedman, Alex; Grant-Logan, B; Grisham, Larry; Lee, Edward; Lee, Richard; Olson, Craig; Rose, David; Santhanam, Parthiban; Sessler, Andrew M; Staples, John W; Tabak, Max; Welch, Dale; Wurtele, Jonathan; Yu, Simon
2005-01-01
One approach to heat a target to "Warm Dense Matter" conditions (similar, for example, to the interiors of giant planets or certain stages in Inertial Confinement Fusion targets), is to use intense ion beams as the heating source. By consideration of ion beam phase space constraints, both at the injector, and at the final focus, and consideration of simple equations of state, approximate conditions at a target foil may be calculated. Thus target temperature and pressure may be calculated as a function of ion mass, ion energy, pulse duration, velocity tilt, and other accelerator parameters. We examine the variation in target performance as a function of various beam and accelerator parameters, in the context of several different accelerator concepts, recently proposed for WDM studies.
Space-Time Characterization of Laser Plasma Interactions in the Warm Dense Matter Regime
Energy Technology Data Exchange (ETDEWEB)
Cao, L F; Uschmann, I; Forster, E; Zamponi, F; Kampfer, T; Fuhrmann, A; Holl, A; Redmer, R; Toleikis, S; Tschentsher, T; Glenzer, S H
2008-04-30
Laser plasma interaction experiments have been performed using a fs Titanium Sapphire laser. Plasmas have been generated from planar PMMA targets using single laser pulses with 3.3 mJ pulse energy, 50 fs pulse duration at 800 nm wavelength. The electron density distributions of the plasmas in different delay times have been characterized by means of Nomarski Interferometry. Experimental data were compared with hydrodynamic simulation. First results to characterize the plasma density and temperature as a function of space and time are obtained. This work aims to generate plasmas in the warm dense matter (WDM) regime at near solid-density in an ultra-fast laser target interaction process. Plasmas under these conditions can serve as targets to develop x-ray Thomson scattering as a plasma diagnostic tool, e.g., using the VUV free-electron laser (FLASH) at DESY Hamburg.
Fungal decomposition of terrestrial organic matter accelerated Early Jurassic climate warming
Pieńkowski, Grzegorz; Hodbod, Marta; Ullmann, Clemens V.
2016-08-01
Soils - constituting the largest terrestrial carbon pool - are vulnerable to climatic warming. Currently existing uncertainties regarding carbon fluxes within terrestrial systems can be addressed by studies of past carbon cycle dynamics and related climate change recorded in sedimentary successions. Here we show an example from the Early Jurassic (early Toarcian, c. 183 mya) marginal-marine strata from Poland, tracking the hinterland response to climatic changes through a super-greenhouse event. In contrast to anoxia-related enhanced carbon storage in coeval open marine environments, Total Organic Carbon (TOC) concentrations in the Polish successions are substantially reduced during this event. Increasing temperature favoured fungal-mediated decomposition of plant litter - specifically of normally resistant woody tissues. The associated injection of oxidized organic matter into the atmosphere corresponds to abrupt changes in standing vegetation and may have contributed significantly to the amplified greenhouse climate on Earth. The characteristic Toarcian signature of multiple warm pulses coinciding with rapidly decreasing carbon isotope ratios may in part be the result of a radical reduction of the terrestrial carbon pool as a response to climate change.
Schnecker, Jörg; Borken, Werner; Schindlbacher, Andreas; Wanek, Wolfgang
2016-12-01
Rising temperatures enhance microbial decomposition of soil organic matter (SOM) and thereby increase the soil CO 2 efflux. Elevated decomposition rates might differently affect distinct SOM pools, depending on their stability and accessibility. Soil fractions derived from density fractionation have been suggested to represent SOM pools with different turnover times and stability against microbial decomposition. To investigate the effect of soil warming on functionally different soil organic matter pools, we here investigated the chemical and isotopic composition of bulk soil and three density fractions (free particulate organic matter, fPOM; occluded particulate organic matter, oPOM; and mineral associated organic matter, MaOM) of a C-rich soil from a long-term warming experiment in a spruce forest in the Austrian Alps. At the time of sampling, the soil in this experiment had been warmed during the snow-free period for seven consecutive years. During that time no thermal adaptation of the microbial community could be identified and CO 2 release from the soil continued to be elevated by the warming treatment. Our results, which included organic carbon content, total nitrogen content, δ 13 C, Δ 14 C, δ 15 N and the chemical composition, identified by pyrolysis-GC/MS, showed no significant differences in bulk soil between warming treatment and control. Surprisingly, the differences in the three density fractions were mostly small and the direction of warming induced change was variable with fraction and soil depth. Warming led to reduced N content in topsoil oPOM and subsoil fPOM and to reduced relative abundance of N-bearing compounds in subsoil MaOM. Further, warming increased the δ 13 C of MaOM at both sampling depths, reduced the relative abundance of carbohydrates while it increased the relative abundance of lignins in subsoil oPOM. As the size of the functionally different SOM pools did not significantly change, we assume that the few and small
International Nuclear Information System (INIS)
Sefkow, Adam B.; Davidson, Ronald C.; Kaganovich, Igor D.; Gilson, Erik P.; Roy, Prabir K.; Seidl, Peter A.; Yu, Simon S.; Welch, Dale R.; Rose, David V.; Barnard, John J.
2007-01-01
Intense, space-charge-dominated ion beam pulses for warm dense matter and heavy ion fusion applications must undergo simultaneous transverse and longitudinal bunch compression in order to meet the requisite beam intensities desired at the target. The longitudinal compression of an ion bunch is achieved by imposing an initial axial velocity tilt on the drifting beam and subsequently neutralizing its space-charge and current in a drift region filled with high-density plasma. The Neutralized Drift Compression Experiment (NDCX) at Lawrence Berkeley National Laboratory has measured a sixty-fold longitudinal current compression of an intense ion beam with pulse duration of a few nanoseconds, in agreement with simulations and theory. A strong solenoid is modeled near the end of the drift region in order to transversely focus the beam to a sub-millimeter spot size coincident with the longitudinal focal plane. The charge and current neutralization provided by the background plasma is critical in determining the total achievable transverse and longitudinal compression of the beam pulse. Numerical simulations show that the current density of an NDCX ion beam can be compressed over a few meters by factors greater than 10 5 with peak beam density in excess of 10 14 cm -3 . The peak beam density sets a lower bound on the local plasma density required near the focal plane for optimal beam compression, since the simulations show stagnation of the compression when n beam >n plasma . Beam-plasma interactions can also have a deleterious effect on the compression physics and lead to the formation of nonlinear wave excitations in the plasma. Simulations that optimize designs for the simultaneous transverse and longitudinal focusing of an NDCX ion beam for future warm dense matter experiments are discussed
Path Integral Monte Carlo Simulations of Warm Dense Matter and Plasmas
Energy Technology Data Exchange (ETDEWEB)
Militzer, Burkhard [Univ. of California, Berkeley, CA (United States)
2018-01-13
New path integral Monte Carlo simulation (PIMC) techniques will be developed and applied to derive the equation of state (EOS) for the regime of warm dense matter and dense plasmas where existing first-principles methods cannot be applied. While standard density functional theory has been used to accurately predict the structure of many solids and liquids up to temperatures on the order of 10,000 K, this method is not applicable at much higher temperature where electronic excitations become important because the number of partially occupied electronic orbitals reaches intractably large numbers and, more importantly, the use of zero-temperature exchange-correlation functionals introduces an uncontrolled approximation. Here we focus on PIMC methods that become more and more efficient with increasing temperatures and still include all electronic correlation effects. In this approach, electronic excitations increase the efficiency rather than reduce it. While it has commonly been assumed such methods can only be applied to elements without core electrons like hydrogen and helium, we recently showed how to extend PIMC to heavier elements by performing the first PIMC simulations of carbon and water plasmas [Driver, Militzer, Phys. Rev. Lett. 108 (2012) 115502]. Here we propose to continue this important development to extend the reach of PIMC simulations to yet heavier elements and also lower temperatures. The goal is to provide a robust first-principles simulation method that can accurately and efficiently study materials with excited electrons at solid-state densities in order to access parts of the phase diagram such the regime of warm dense matter and plasmas where so far only more approximate, semi-analytical methods could be applied.
Phases of kinky holographic nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Elliot-Ripley, Matthew; Sutcliffe, Paul; Zamaklar, Marija [Department of Mathematical Sciences, Durham University,South Road, Durham (United Kingdom)
2016-10-17
Holographic QCD at finite baryon number density and zero temperature is studied within the five-dimensional Sakai-Sugimoto model. We introduce a new approximation that models a smeared crystal of solitonic baryons by assuming spatial homogeneity to obtain an effective kink theory in the holographic direction. The kink theory correctly reproduces a first order phase transition to lightly bound nuclear matter. As the density is further increased the kink splits into a pair of half-kink constituents, providing a concrete realization of the previously suggested dyonic salt phase, where the bulk soliton splits into constituents at high density. The kink model also captures the phenomenon of baryonic popcorn, in which a first order phase transition generates an additional soliton layer in the holographic direction. We find that this popcorn transition takes place at a density below the dyonic salt phase, making the latter energetically unfavourable. However, the kink model predicts only one pop, rather than the sequence of pops suggested by previous approximations. In the kink model the two layers produced by the single pop form the surface of a soliton bag that increases in size as the baryon chemical potential is increased. The interior of the bag is filled with abelian electric potential and the instanton charge density is localized on the surface of the bag. The soliton bag may provide a holographic description of a quarkyonic phase.
Kaons in nuclear matter; Kaonen in Kernmaterie
Energy Technology Data Exchange (ETDEWEB)
Kolomeitsev, E.E.
1997-02-01
The subject of the doctoral thesis is examination of the properties of kaons in nuclear matter. A specific method is explained that has been developed for the scientific objectives of the thesis and permits description of the kaon-nucleon interactions and kaon-nucleon scattering in a vacuum. The main challenge involved was to find approaches that would enable application of the derived relations out of the kaon mass shell, connected with the second objective, namely to possibly find methods which are independent of models. The way chosen to achieve this goal relied on application of reduction formulas as well as current algebra relations and the PCAC hypothesis. (orig./CB) [Deutsch] Die Arbeit befasst sich mit der Untersuchung der Eigenschaften von Kao nen in Kernmaterie. Zu diesem Zweck wurde ein Verfahren entwickelt, di e Kaon- Nukleon- Wechselwirkung und Kaon- Nukleon- Streuung im Vakuumzu beschreiben. Die Hauptherausforderung bestand darin, dass die abgel eiteten Relationen ausserhalb der Kaonen- Massenschale anwendbar werde n. Eine Nebenforderung war, dass die vorgeschlagenen Verfahren moeglic hst modell- unabhaengig sind. Um dieses Ziel zu erreichen, wurden Redu ktionsformeln, Stromalgebra- Relationen und die PCAC- Hypothese angewe ndet.
Track theory and nuclear photographic emulsions for Dark Matter searches
International Nuclear Information System (INIS)
Ditlov, V.A.
2013-01-01
This work is devoted to the analysis of possibilities of nuclear emulsions for Dark Matter search, particles of which can produce slow recoil-nuclei. Tracks of such recoil-nuclei in developed nuclear emulsion consist from several emulsion grains. The analysis was carried out with Monte-Carlo calculations made on the basis of the Track Theory and the various factors influencing Dark Matter particles registration efficiency were investigated. Problems, which should be solved for optimal utilization of nuclear emulsions in Dark Matter search, were formulated. B ody - Highlights: ► Specific features of Dark Matter Search in nuclear photographic emulsions. ► Track theory for WIMP search in nuclear emulsions. ► Primary efficiency for single WIMP registration. ► Properties of primary WIMP registration efficiency. ► Primary registration efficiency of WIMP flow
A Limit on the Warm Dark Matter Particle Mass from the Redshifted 21 cm Absorption Line
Safarzadeh, Mohammadtaher; Scannapieco, Evan; Babul, Arif
2018-06-01
The recent Experiment to Detect the Global Epoch of Reionization Signature (EDGES) collaboration detection of an absorption signal at a central frequency of ν = 78 ± 1 MHz points to the presence of a significant Lyα background by a redshift of z = 18. The timing of this signal constrains the dark matter particle mass (m χ ) in the warm dark matter (WDM) cosmological model. WDM delays the formation of small-scale structures, and therefore a stringent lower limit can be placed on m χ based on the presence of a sufficiently strong Lyα background due to star formation at z = 18. Our results show that coupling the spin temperature to the gas through Lyα pumping requires a minimum mass of m χ > 3 keV if atomic cooling halos dominate the star formation rate at z = 18, and m χ > 2 keV if {{{H}}}2 cooling halos also form stars efficiently at this redshift. These limits match or exceed the most stringent limits cited to date in the literature, even in the face of the many uncertainties regarding star formation at high redshift.
Proton acceleration experiments and warm dense matter research using high power lasers
Energy Technology Data Exchange (ETDEWEB)
Roth, M; Alber, I; Guenther, M; Harres, K [Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Bagnoud, V [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Brown, C R D [Plasma Physics Group, Imperial College London, SW7 2BZ (United Kingdom); Clarke, R; Heathcote, R; Li, B [STFC, Rutherford Appleton Laboratory (RAL), Chilton, Didcot, OX14 OQX (United Kingdom); Daido, H [Photo Medical Research Center, JAEA, Kizugawa-City, Kyoto 619-0215 (Japan); Fernandez, J; Flippo, K; Gaillard, S; Gauthier, C [Los Alamos National Laboratory (LANL), Los Alamos, NM 87545 (United States); Geissel, M [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Glenzer, S; Kritcher, A; Kugland, N; LePape, S [Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States); Gregori, G, E-mail: markus.roth@physik.tu-darmstadt.d [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom)
2009-12-15
The acceleration of intense proton and ion beams by ultra-intense lasers has matured to a point where applications in basic research and technology are being developed. Crucial for harvesting the unmatched beam parameters driven by the relativistic electron sheath is the precise control of the beam. In this paper we report on recent experiments using the PHELIX laser at GSI, the VULCAN laser at RAL and the TRIDENT laser at LANL to control and use laser accelerated proton beams for applications in high energy density research. We demonstrate efficient collimation of the proton beam using high field pulsed solenoid magnets, a prerequisite to capture and transport the beam for applications. Furthermore, we report on two campaigns to use intense, short proton bunches to isochorically heat solid targets up to the warm dense matter state. The temporal profile of the proton beam allows for rapid heating of the target, much faster than the hydrodynamic response time thereby creating a strongly coupled plasma at solid density. The target parameters are then probed by x-ray Thomson scattering to reveal the density and temperature of the heated volume. This combination of two powerful techniques developed during the past few years allows for the generation and investigation of macroscopic samples of matter in states present in giant planets or the interior of the earth.
Proton acceleration experiments and warm dense matter research using high power lasers
International Nuclear Information System (INIS)
Roth, M; Alber, I; Guenther, M; Harres, K; Bagnoud, V; Brown, C R D; Clarke, R; Heathcote, R; Li, B; Daido, H; Fernandez, J; Flippo, K; Gaillard, S; Gauthier, C; Geissel, M; Glenzer, S; Kritcher, A; Kugland, N; LePape, S; Gregori, G
2009-01-01
The acceleration of intense proton and ion beams by ultra-intense lasers has matured to a point where applications in basic research and technology are being developed. Crucial for harvesting the unmatched beam parameters driven by the relativistic electron sheath is the precise control of the beam. In this paper we report on recent experiments using the PHELIX laser at GSI, the VULCAN laser at RAL and the TRIDENT laser at LANL to control and use laser accelerated proton beams for applications in high energy density research. We demonstrate efficient collimation of the proton beam using high field pulsed solenoid magnets, a prerequisite to capture and transport the beam for applications. Furthermore, we report on two campaigns to use intense, short proton bunches to isochorically heat solid targets up to the warm dense matter state. The temporal profile of the proton beam allows for rapid heating of the target, much faster than the hydrodynamic response time thereby creating a strongly coupled plasma at solid density. The target parameters are then probed by x-ray Thomson scattering to reveal the density and temperature of the heated volume. This combination of two powerful techniques developed during the past few years allows for the generation and investigation of macroscopic samples of matter in states present in giant planets or the interior of the earth.
Mixing rules for optical and transport properties of warm, dense matter
International Nuclear Information System (INIS)
Kress, Joel D.; Horner, Daniel A.; Collins, Lee A.
2009-01-01
The warm, dense matter (WDM) regime requires a sophisticated treatment since neither ideal gas laws or fully ionized plasma models apply. Mixtures represent the predominant form of matter throughout the universe and the ability to predict the properties of a mixture, though direct simulation or from convolution of the properties of the constituents is both a challenging prospect and an important goal. Through quantum molecular dynamics (QMD), we accurately simulate WDM and compute equations of state, transport, and optical properties of such materials, including mixtures, in a self-consistent manner from a single simulation. With the ability to directly compute the mixture properties, we are able to validate mixing rules for combining the optical and dynamical properties of Li and H separately to predict the properties of lithium hydride (LiH). We have examined two such mixing rules and extend them to morphologies beyond a simple liquid alloy. We have also studied a mixture of polyethylene and aluminum at T = 1 eV.
The warm dark matter halo mass function below the cut-off scale
Angulo, Raul E.; Hahn, Oliver; Abel, Tom
2013-10-01
Warm dark matter (WDM) cosmologies are a viable alternative to the cold dark matter (CDM) scenario. Unfortunately, an accurate scrutiny of the WDM predictions with N-body simulations has proven difficult due to numerical artefacts. Here, we report on cosmological simulations that, for the first time, are devoid of those problems, and thus are able to accurately resolve the WDM halo mass function well below the cut-off. We discover a complex picture, with perturbations at different evolutionary stages populating different ranges in the halo mass function. On the smallest mass scales we can resolve, identified objects are typically centres of filaments that are starting to collapse. On intermediate mass scales, objects typically correspond to fluctuations that have collapsed and are in the process of relaxation, whereas the high-mass end is dominated by objects similar to haloes identified in CDM simulations. We then explicitly show how the formation of low-mass haloes is suppressed, which translates into a strong cut-off in the halo mass function. This disfavours some analytic formulations that predict a halo mass function that would extend well below the free streaming mass. We argue for a more detailed exploration of the formation of the smallest structures expected to form in a given cosmology, which, we foresee, will advance our overall understanding of structure formation.
Reflection on penal policy in nuclear matters
International Nuclear Information System (INIS)
Cisse, A.
1996-01-01
This document expresses ethical reflexions as far as nuclear energy development is concerned. The potential diversion of the peaceful use of nuclear energy results in the necessity of a criminal policy which would control the nuclear regulations. For each potential nuclear infringement, systems of laws are established either to prevent damages or to penalize them. (TEC)
Energy Technology Data Exchange (ETDEWEB)
Mo, M. Z., E-mail: mmo09@slac.stanford.edu; Shen, X.; Chen, Z.; Li, R. K.; Dunning, M.; Zheng, Q.; Weathersby, S. P.; Reid, A. H.; Coffee, R.; Makasyuk, I.; Edstrom, S.; McCormick, D.; Jobe, K.; Hast, C.; Glenzer, S. H.; Wang, X. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Sokolowski-Tinten, K. [Faculty of Physics and Centre for Nanointegration Duisburg-Essen, University of Duisburg-Essen, Lotharstrasse 1, D-47048 Duisburg (Germany)
2016-11-15
We have developed a single-shot mega-electronvolt ultrafast-electron-diffraction system to measure the structural dynamics of warm dense matter. The electron probe in this system is featured by a kinetic energy of 3.2 MeV and a total charge of 20 fC, with the FWHM pulse duration and spot size at sample of 350 fs and 120 μm respectively. We demonstrate its unique capability by visualizing the atomic structural changes of warm dense gold formed from a laser-excited 35-nm freestanding single-crystal gold foil. The temporal evolution of the Bragg peak intensity and of the liquid signal during solid-liquid phase transition are quantitatively determined. This experimental capability opens up an exciting opportunity to unravel the atomic dynamics of structural phase transitions in warm dense matter regime.
International Nuclear Information System (INIS)
Sasaki, Toru; Miki, Yasutoshi; Tachinami, Fumitaka; Saito, Hirotaka; Takahashi, Takuya; Anzai, Nobuyuki; Kikuchi, Takashi; Aso, Tsukasa; Harada, Nob.
2014-01-01
In order to explore high energy density physics, we have performed WDM experiment by using several pulsed-power devices. To generate well-defined warm dense state for evaluating electrical conductivity and its properties, we have proposed an isochoric heating of foamed metal by using pulsed-power discharge. The proposed technique yields the electrical conductivity of warm dense matter with a well-defined temperature. To observe the warm dense matter, a pulsed-power generator based on a pulse-forming-network (PFN) was studied toward generating an intense point-spot-like X-ray source from X-pinch technique. From comparison of the designing and the actual inductances of the X-pinch system, the actual inductance of X-pinch system is 3.5 times higher than the designing inductance. To reduce the total inductance of X-pinch system, we will modify the gap switch system such as multi spake gap
Clustering phenomena in nuclear matter below the saturation density
International Nuclear Information System (INIS)
Takemoto, Hiroki; Fukushima, Masahiro; Chiba, Satoshi; Horiuchi, Hisashi; Akaishi, Yoshinori; Tohsaki, Akihiro
2004-01-01
We investigate density-fluctuated states of nuclear matter as a result of clustering below the saturation density ρ 0 by description in terms of the Bloch function. The Bloch description has the advantage of a unified representation for a density-fluctuated state from an aggregate of uncorrelated clusters in extremely low-density regions to the plane-wave state of uniform matter in relatively high-density regions. We treat the density-fluctuated states due to α and 16 O clustering in symmetric nuclear matter and due to 10 He clustering in asymmetric nuclear matter. The density-fluctuated states develop as the density of matter decreases below each critical density around 0.2-0.4 ρ 0 which depends on what kind of effective force we use
What role can nuclear power play in mitigating global warming?
International Nuclear Information System (INIS)
Pasztor, J.
1989-12-01
The purpose of this paper is to look at nuclear fission, as one of the available options, and evaluate qualitatively the extent to which it can play a role in greenhouse gas reduction strategies during the next three decades. No attempt will be made here to make a quantitative comparison with alternative energy supplies, or with energy efficiency measures
Monotonous braking of high energy hadrons in nuclear matter
International Nuclear Information System (INIS)
Strugalski, Z.
1979-01-01
Propagation of high energy hadrons in nuclear matter is discussed. The possibility of the existence of the monotonous energy losses of hadrons in nuclear matter is considered. In favour of this hypothesis experimental facts such as pion-nucleus interactions (proton emission spectra, proton multiplicity distributions in these interactions) and other data are presented. The investigated phenomenon in the framework of the hypothesis is characterized in more detail
Many-body theory of nuclear and neutron star matter
Energy Technology Data Exchange (ETDEWEB)
Pandharipande, V R; Akmal, A; Ravenhall, D G [Dept. of Physics, Univ. of Illinois at Urbana-Champaign, Urbana, IL (United States)
1998-06-01
We present results obtained for nuclei, nuclear and neutron star matter, and neutron star structure obtained with the recent Argonne v{sub 18} two- nucleon and Urbana IX three-nucleon interactions including relativistic boost corrections. These interactions predict that matter will undergo a transition to a spin layered phase with neutral pion condensation. We also consider the possibility of a transition to quark matter. (orig.)
Many-body theory of nuclear and neutron star matter
International Nuclear Information System (INIS)
Pandharipande, V.R.; Akmal, A.; Ravenhall, D.G.
1998-01-01
We present results obtained for nuclei, nuclear and neutron star matter, and neutron star structure obtained with the recent Argonne v 18 two- nucleon and Urbana IX three-nucleon interactions including relativistic boost corrections. These interactions predict that matter will undergo a transition to a spin layered phase with neutral pion condensation. We also consider the possibility of a transition to quark matter. (orig.)
Nuclear incompressibility: from finite nuclei to nuclear matter
International Nuclear Information System (INIS)
Treiner, J.; Krivine, H.; Bohigas, O.
1981-01-01
The recent increase of experimental data concerning the Giant Monopole Resonance Energy Esub(M) gives information on the incompressibility modulus of nuclear matter, provided one can extrapolate the incompressibility of a nucleus Ksub(A) defined by Esub(M)=[h 2 /m KA/ 2 >]sup(1/2), to the infinite medium. We discuss the theoretical interpretation of the coefficients of an Asup(-1/3) - expansion of Ksub(A) by studying the asymptotic behaviour of two RPA sum rules (corresponding to the scaling and the constrained model), evaluated using self-consistent Thomas-Fermi calculations. We show that the scaling model is the most suitable one as it leads to a rapidly converging Asup(-1/3)-expansion of the corresponding incompressibility Ksub(A)sup(S), whereas this is not the case with the constrained model. Some semi-empirical relations between the coefficients of the expansion of Ksub(A)sup(S) are established, which reduce to one the number of free-parameters in a best fit analysis of the experimental data. This reduction is essential due to the still limited number and accuracy of experimental data. We then show the compatibility of the data given by the various experimental groups with this parametrization and obtain a value of Ksub(nm)=220+-20 MeV, in good agreement with more microscopic analysis
Liquid-gas phase transition in asymmetric nuclear matter at finite temperature
International Nuclear Information System (INIS)
Maruyama, Toshiki; Tatsumi, Toshitaka; Chiba, Satoshi
2010-01-01
Liquid-gas phase transition is discussed in warm asymmetric nuclear matter. Some peculiar features are figured out from the viewpoint of the basic thermodynamics about the phase equilibrium. We treat the mixed phase of the binary system based on the Gibbs conditions. When the Coulomb interaction is included, the mixed phase is no more uniform and the sequence of the pasta structures appears. Comparing the results with those given by the simple bulk calculation without the Coulomb interaction, we extract specific features of the pasta structures at finite temperature.
Liquid-gas phase transition in asymmetric nuclear matter at finite temperature
Maruyama, Toshiki; Tatsumi, Toshitaka; Chiba, Satoshi
2010-03-01
Liquid-gas phase transition is discussed in warm asymmetric nuclear matter. Some peculiar features are figured out from the viewpoint of the basic thermodynamics about the phase equilibrium. We treat the mixed phase of the binary system based on the Gibbs conditions. When the Coulomb interaction is included, the mixed phase is no more uniform and the sequence of the pasta structures appears. Comparing the results with those given by the simple bulk calculation without the Coulomb interaction, we extract specific features of the pasta structures at finite temperature.
THE INNER STRUCTURE OF DWARF-SIZED HALOS IN WARM AND COLD DARK MATTER COSMOLOGIES
Energy Technology Data Exchange (ETDEWEB)
González-Samaniego, A.; Avila-Reese, V. [Instituto de Astronomía, Universidad Nacional Autónoma de México, A.P. 70-264, 04510, México, D.F., México (Mexico); Colín, P. [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, A.P. 72-3 (Xangari), Morelia, Michoacán 58089, México (Mexico)
2016-03-10
By means of N-body + hydrodynamic zoom-in simulations we study the evolution of the inner dark matter and stellar mass distributions of central dwarf galaxies formed in halos of virial masses M{sub v} = (2–3) × 10{sup 10} h{sup −1} M{sub ⊙} at z = 0, both in a warm dark matter (WDM) and cold dark matter (CDM) cosmology. The half-mode mass in the WDM power spectrum of our simulations is M{sub f} = 2 × 10{sup 10} h{sup −1} M{sub ⊙}. In the dark matter (DM) only simulations halo density profiles are well described by the Navarro–Frenk–White parametric fit in both cosmologies, though the WDM halos have concentrations lower by factors of 1.5–2.0 than their CDM counterparts. In the hydrodynamic simulations, the effects of baryons significantly flatten the inner density, velocity dispersion, and pseudo phase space density profiles of the WDM halos but not of the CDM ones. The density slope, measured at ≈0.02R{sub v}, α{sub 0.02}, becomes shallow in periods of 2–5 Gyr in the WDM runs. We explore whether this flattening process correlates with the global star formation (SF), M{sub s}/M{sub v} ratio, gas outflow, and internal specific angular momentum histories. We do not find any clear trends, but when α{sub 0.02} is shallower than −0.5, M{sub s}/M{sub v} is always between 0.25% and 1%. We conclude that the main reason for the formation of the shallow core is the presence of strong gas mass fluctuations inside the inner halo, which are a consequence of the feedback driven by a very bursty and sustained SF history in shallow gravitational potentials. Our WDM halos, which assemble late and are less concentrated than the CDM ones, obey these conditions. There are also (rare) CDM systems with extended mass assembly histories that obey these conditions and form shallow cores. The dynamical heating and expansion processes behind the DM core flattening apply also to the stars in such a way that the stellar age and metallicity gradients of the
The role of meson dynamics in nuclear matter saturation
International Nuclear Information System (INIS)
Goncalves, E.
1988-01-01
The problem of the saturation of nuclea matter in the non-relativistic limit of the model proposed by J.D. Walecka is studied. In the original context nuclear matter saturation is obtained as a direct consequence of relativistic effects and both scalar and vector mesons are treated statically. In the present work we investigate the effect of the meson dynamics for the saturation using a Born-Oppenheimer approximation for the ground state. An upper limit for the saturation curve of nuclear matter and are able to decide now essential is the relativistic treatment of the nucleons for this problem, is obtained. (author) [pt
Photons in dense nuclear matter: Random-phase approximation
Stetina, Stephan; Rrapaj, Ermal; Reddy, Sanjay
2018-04-01
We present a comprehensive and pedagogic discussion of the properties of photons in cold and dense nuclear matter based on the resummed one-loop photon self-energy. Correlations among electrons, muons, protons, and neutrons in β equilibrium that arise as a result of electromagnetic and strong interactions are consistently taken into account within the random phase approximation. Screening effects, damping, and collective excitations are systematically studied in a fully relativistic setup. Our study is relevant to the linear response theory of dense nuclear matter, calculations of transport properties of cold dense matter, and investigations of the production and propagation of hypothetical vector bosons such as the dark photons.
The thermal curve of nuclear matter
International Nuclear Information System (INIS)
Ma, Y.G.; Peter, J.; Siwek, A.; Bocage, F.; Bougault, R.; Brou, R.; Colin, J.; Cussol, D.; Durand, D.; Genouin-Duhamel, E.; Gulminelli, F.; Lecolley, J.F.; Lefort, T.; Le Neindre, N.; Lopez, O.; Louvel, M.; Nguyen, A.D.; Steckmeyer, J.C.; Tamain, B.; Vient, E.
1997-01-01
Earlier measurements of nuclear matter thermal curve of liquid to gas phase transition presented two limitation: only one temperature measuring method was available and the mass number of the formed nuclei decreased from 190 to 50 when the excitation energy increased. To avoid these limitations experiments with the multidetector INDRA at GANIL were carried-out. Among the quasi-projectiles issued from the 36 Ar collisions at 52, 74, 95 A.MeV on the 58 Ni, nuclei of close masses were selected. The excitation energy was determined by the calorimetry of the charged products emitted by quasi-projectiles while the temperature was measured by three different methods. Very different apparent temperatures were obtained for the same excitation energy/nucleon. Only one curve displays a slope variation but no indication of plateau. With the quasi-projectiles obtained from the collisions of 129 Xe at 50 MeV/u on a 119 Sn target behaviors similar to those of 36 Ar were observed in the covered domain of excitation energy. To solve this puzzle and recover the initial temperatures of interest the only mean was to do a theoretical simulation in which one follows the de-excitation of the nuclei formed at different excitation energies and look for the thermal curve able to reproduce the observed temperatures. Two extreme possibilities were taken into account concerning the de-excitation process: either a sequential process established at E * /A≤ 3 MeV/u or a sudden multifragmentation in several hot fragments, most probably at E * /A≥ 10 MeV/u. In both cases it was possible to reproduce the whole set of experimental results concerning the 36 Ar projectile. The initial temperature increases steadily as a function of excitation energy showing no plateau or singular points. The results indicate that, being a system without external pressure, in its passage from the liquid phase to the gas phase the nucleus does not display necessarily a temperature plateau. Discussions on
Nuclear spin warm up in bulk n -GaAs
Kotur, M.; Dzhioev, R. I.; Vladimirova, M.; Jouault, B.; Korenev, V. L.; Kavokin, K. V.
2016-08-01
We show that the spin-lattice relaxation in n -type insulating GaAs is dramatically accelerated at low magnetic fields. The origin of this effect, which cannot be explained in terms of well-known diffusion-limited hyperfine relaxation, is found in the quadrupole relaxation, induced by fluctuating donor charges. Therefore, quadrupole relaxation, which governs low field nuclear spin relaxation in semiconductor quantum dots, but was so far supposed to be harmless to bulk nuclei spins in the absence of optical pumping, can be studied and harnessed in the much simpler model environment of n -GaAs bulk crystal.
Introduction of nuclear power plant for mitigating the impact of global warming
International Nuclear Information System (INIS)
Ida Nuryatin Finahari
2008-01-01
Energy utilization for power plants in Indonesia is still highly depending on the burning of fossil fuel like coal, oil, and gas. From the combustion of fossil fuel, greenhouse gases such as CO 2 and N 2 O are produced. An increase of CO 2 gas emission to the atmosphere can block the heat loss from the earth surface and will increase the greenhouse effect that results in the temperature increase of the earth surface (global warming). Global warming can cause a very extreme climate change on earth. One of the solutions to reduce CO 2 gas emission produced by fossil fuel power plants is to utilize the plants with flue gas treatment facility. At such facility, CO 2 gas is reacted with certain mineral based substances thus can be used as base material in food-, pharmaceutical-, construction-, and cosmetic industry. Another alternative to reduce CO 2 gas emission is by replacing fossil fuel power plants with nuclear power plants. Considering the environmental and economic aspects, the nuclear power plant does not emit CO 2 gas, so that the use of nuclear power plant can mitigate the impact of global warming. Based on the operational experience of nuclear power plants in advanced countries, the cost of generating electricity from nuclear power plants is more competitive than that of fossil fuel power plant. (author)
Nuclear energy, a solution in the struggle against global warming in quest of recognition
International Nuclear Information System (INIS)
Faudon, Valerie
2014-01-01
In this article, the author first comments assessments of the continuous increase of greenhouse gas emissions as they appear in the IPCC report of September 2013 and in the results published by the Global Carbon Project. She also evokes the commitments in emission reductions in compliance with the Kyoto Protocol and some dramatic consequences global warming may have according to the IPCC scenarios. Then, she addresses the share of nuclear energy in energy production and outlines its stakes and benefits in terms of greenhouse gas emissions. She notices that international bodies (European Commission, World Bank) do not mention nuclear energy in their plan for energy production development, but mainly rely on the development of renewable energies. The author then outlines the reasons why the development of renewable energies does not necessarily goes with the reduction of greenhouse gas emissions. She also notices that a new generation of ecologists considers nuclear energy as a tool to struggle against climate warming
Pion condensation and density isomerism in nuclear matter
International Nuclear Information System (INIS)
Hecking, P.; Weise, W.
1979-01-01
The possible existence of density isomers in nuclear matter, induced by pion condensation, is discussed; the nuclear equation of state is treated within the framework of the sigma model. Repulsive short-range baryon-baryon correlations, the admixture of Δ (1232) isobars and finite-range pion-baryon vertex form factors are taken into account. The strong dependence of density isomerism on the high density extrapolation of the equation of state for normal nuclear matter is also investigated. We find that, once finite range pion-baryon vertices are introduced, the appearance of density isomers becomes unlikely
The determination of nuclear matter temperature and density
International Nuclear Information System (INIS)
Wolf, K.L.
1981-01-01
The purpose of this paper is to review some of the things we have learned about nuclear matter under extreme conditions during the past few years in relativistic heavy ion studies. High energy heavy-ion collisions provide a unique mechanism for exploring the dependence of the nuclear potential energy epsilon(rho,T) on the degree of compression and excitation, and may even show the existence of new phases of matter. Thus the determination of the nuclear equation of state remains the ultimate goal of many researchers in this field. (orig.)
QCD sum rule for nucleon in nuclear matter
International Nuclear Information System (INIS)
Mallik, S.; Sarkar, Sourav
2010-01-01
We consider the two-point function of nucleon current in nuclear matter and write a QCD sum rule to analyse the residue of the nucleon pole as a function of nuclear density. The nucleon self-energy needed for the sum rule is taken as input from calculations using phenomenological N N potential. Our result shows a decrease in the residue with increasing nuclear density, as is known to be the case with similar quantities. (orig.)
Short intense ion pulses for materials and warm dense matter research
Energy Technology Data Exchange (ETDEWEB)
Seidl, Peter A., E-mail: PASeidl@lbl.gov [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Persaud, Arun; Waldron, William L. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Barnard, John J. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Davidson, Ronald C. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Friedman, Alex [Lawrence Livermore National Laboratory, Livermore, CA (United States); Gilson, Erik P. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Greenway, Wayne G. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Grote, David P. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Kaganovich, Igor D. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Lidia, Steven M.; Stettler, Matthew; Takakuwa, Jeffrey H.; Schenkel, Thomas [Lawrence Berkeley National Laboratory, Berkeley, CA (United States)
2015-11-11
We have commenced experiments with intense short pulses of ion beams on the Neutralized Drift Compression Experiment-II at Lawrence Berkeley National Laboratory, by generating beam spots size with radius r<1 mm within 2 ns FWHM and approximately 10{sup 10} ions/pulse. To enable the short pulse durations and mm-scale focal spot radii, the 1.2 MeV Li{sup +} ion beam is neutralized in a 1.6-meter drift compression section located after the last accelerator magnet. An 8-Tesla short focal length solenoid compresses the beam in the presence of the large volume plasma near the end of this section before the target. The scientific topics to be explored are warm dense matter, the dynamics of radiation damage in materials, and intense beam and beam-plasma physics including selected topics of relevance to the development of heavy-ion drivers for inertial fusion energy. Here we describe the accelerator commissioning and time-resolved ionoluminescence measurements of yttrium aluminum perovskite using the fully integrated accelerator and neutralized drift compression components.
Short intense ion pulses for materials and warm dense matter research
International Nuclear Information System (INIS)
Seidl, Peter A.; Persaud, Arun; Waldron, William L.; Barnard, John J.; Davidson, Ronald C.; Friedman, Alex; Gilson, Erik P.; Greenway, Wayne G.; Grote, David P.; Kaganovich, Igor D.; Lidia, Steven M.; Stettler, Matthew; Takakuwa, Jeffrey H.; Schenkel, Thomas
2015-01-01
We have commenced experiments with intense short pulses of ion beams on the Neutralized Drift Compression Experiment-II at Lawrence Berkeley National Laboratory, by generating beam spots size with radius r<1 mm within 2 ns FWHM and approximately 10"1"0 ions/pulse. To enable the short pulse durations and mm-scale focal spot radii, the 1.2 MeV Li"+ ion beam is neutralized in a 1.6-meter drift compression section located after the last accelerator magnet. An 8-Tesla short focal length solenoid compresses the beam in the presence of the large volume plasma near the end of this section before the target. The scientific topics to be explored are warm dense matter, the dynamics of radiation damage in materials, and intense beam and beam-plasma physics including selected topics of relevance to the development of heavy-ion drivers for inertial fusion energy. Here we describe the accelerator commissioning and time-resolved ionoluminescence measurements of yttrium aluminum perovskite using the fully integrated accelerator and neutralized drift compression components.
PLANS FOR WARM DENSE MATTER EXPERIMENTS AND IFE TARGET EXPERIMENTS ON NDCX-II
International Nuclear Information System (INIS)
Waldron, W.L.; Barnard, J.J.; Bieniosek, F.M.; Friedman, A.; Henestroza, E.; Leitner, M.; Logan, B.G.; Ni, P.A.; Roy, P.K.; Seidl, P.A.; Sharp, W.M.
2008-01-01
The Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL) is currently developing design concepts for NDCX-II, the second phase of the Neutralized Drift Compression Experiment, which will use ion beams to explore Warm Dense Matter (WDM) and Inertial Fusion Energy (IFE) target hydrodynamics. The ion induction accelerator will consist of a new short pulse injector and induction cells from the decommissioned Advanced Test Accelerator (ATA) at Lawrence Livermore National Laboratory (LLNL). To fit within an existing building and to meet the energy and temporal requirements of various target experiments, an aggressive beam compression and acceleration schedule is planned. WDM physics and ion-driven direct drive hydrodynamics will initially be explored with 30 nC of lithium ions in experiments involving ion deposition, ablation, acceleration and stability of planar targets. Other ion sources which may deliver higher charge per bunch will be explored. A test stand has been built at Lawrence Berkeley National Laboratory (LBNL) to test refurbished ATA induction cells and pulsed power hardware for voltage holding and ability to produce various compression and acceleration waveforms. Another test stand is being used to develop and characterize lithium-doped aluminosilicate ion sources. The first experiments will include heating metallic targets to 10,000 K and hydrodynamics studies with cryogenic hydrogen targets
Nuclear energy - a green energy solution to global warming
International Nuclear Information System (INIS)
Malhotra, S.K.
2013-01-01
The manner in which the world has conducted itself in exploiting energy resources so far particularly in the post industrial revolution period, is now looming as one of the greatest challenges to the sustainability of development or even sustainability of life. Global climate change is no more a perceived threat, it is now a reality and we are not in a position to engage ourselves to debate on the issue. It is in fact a little late in taking the right corrective action if we have any concern for our future generations. The efforts of the scientists and engineers are to gradually replace the energy from burning of carbonaceous material to clean and intense source of energy i.e. nuclear fission and fusion
From quantum to semiclassical kinetic equations: Nuclear matter estimates
International Nuclear Information System (INIS)
Galetti, D.; Mizrahi, S.S.; Nemes, M.C.; Toledo Piza, A.F.R. de
1985-01-01
Starting from the exact microscopic time evolution of the quantum one body density associated with a many fermion system semiclassical approximations are derived to it. In the limit where small momentum transfer two body collisions are dominant we get a Fokker-Planck equation and work out friction and diffusion tensors explicitly for nuclear matter. If arbitrary momentum transfers are considered a Boltzmann equation is derived and used to calculate the viscosity coefficient of nuclear matter. A derivation is given of the collision term used by Landau to describe the damping of zero sound waves at low temperature in Plasmas. Memory effects are essential for this. The damping of zero sound waves in nuclear matter is also calculated and the value so obtained associated with the bulk value of the damping of giant resonances in finite nuclei. The bulk value is estimated to be quite small indicating the importance of the nuclear surface for the damping. (Author) [pt
Is nuclear power part of Australia's global warming solutions?
International Nuclear Information System (INIS)
Lowe, I.
2007-01-01
Forty years ago, I was preparing for my final exams. Having studied electrical engineering and science part-time for seven years at the University of New South Wales, I did well enough to spend the following year doing honours in physics. I then went to the United Kingdom for doctoral studies at the University of York, supported by the UK Atomic Energy Authority. At the time, like most young physicists, I saw nuclear power as the clean energy source of the future. Here, I want to tell you why my professional experience has led me to reject that view. There is no serious doubt that climate change is real, it is happening now and its effects are accelerating. It is already causing serious economic impacts: reduced agricultural production, increased costs of severe events like fires and storms, and the need to consider radical, energy-intensive and costly water supply measures such as desalination plants. The alarming consequences of climate change have driven distinguished scientists like James Lovelock to conclude that the situation is desperate enough to reconsider our attitude to nuclear power. I agree with Lovelock about the urgency of the situation, but not about the response. The science is very clear. We need to reduce global greenhouse pollution by about 60%, ideally by 2050. To achieve that global target, allowing for the legitimate material expectations of poorer countries, Australia's quota will need to be at least as strong as the UK's goal of 60% by 2050 and preferably stronger. Our eventual goal will probably be to reduce our greenhouse pollution by 80-90%. How can we reach this ambitious target?
Baltar, Federico
2017-04-19
Extracellular enzymatic activities (EEAs) are the rate-limiting step in the degradation of organic matter. Extracellular enzymes can be found associated to cells or dissolved in the surrounding water. The proportion of cell-free EEA constitutes in many marine environments more than half of the total activity. This high proportion causes an uncoupling between hydrolysis rates and the actual bacterial activity. However, we do not know what factors control the proportion of dissolved relative to total EEA, nor how this may change in the future ocean. To resolve this, we performed laboratory experiments with water from the Great Barrier Reef (Australia) to study the effects of temperature and dissolved organic matter sources on EEA and the proportion of dissolved EEA. We found that warming increases the rates of organic matter hydrolysis and reduces the proportion of dissolved relative to total EEA. This suggests a potential increase of the coupling between organic matter hydrolysis and heterotrophic activities with increasing ocean temperatures, although strongly dependent on the organic matter substrates available. Our study suggests that local differences in the organic matter composition in tropical coastal ecosystems will strongly affect the proportion of dissolved EEA in response to ocean warming.
Simulations of cold nuclear matter at sub-saturation densities
Energy Technology Data Exchange (ETDEWEB)
Giménez Molinelli, P.A., E-mail: pagm@df.uba.ar [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, Buenos Aires 1428 (Argentina); Nichols, J.I. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, Buenos Aires 1428 (Argentina); López, J.A. [Department of Physics, University of Texas at El Paso, El Paso, TX 79968 (United States); Dorso, C.O. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, Buenos Aires 1428 (Argentina)
2014-03-01
Ideal nuclear matter is expected to undergo a first order phase transition at the thermodynamic limit. At such phase transitions the size of density fluctuations (bubbles or droplets) scale with the size of the system. This means that simulations of nuclear matter at sub-saturation densities will inexorably suffer from what is vaguely referred to as “finite size effects”. It is usually thought that these finite size effects can be diminished by imposing periodic boundary conditions and making the system large enough, but as we show in this work, that is actually not the case at sub-saturation densities. In this paper we analyze the equilibrium configurations of molecular dynamics simulations of a classical model for symmetric ideal (uncharged) nuclear matter at sub-saturation densities and low temperatures, where phase coexistence is expected at the thermodynamic limit. We show that the most stable configurations in this density range are almost completely determined by artificial aspects of the simulations (i.e. boundary conditions) and can be predicted analytically by surface minimization. This result is very general and is shown to hold true for several well known semi-classical models of nuclear interaction and even for a simple Lennard-Jones potential. Also, in the limit of very large systems, when “small size” effects can be neglected, those equilibrium configurations seem to be restricted to a few structures reminiscent to the “Pasta Phases” expected in Neutron Star matter, but arising from a completely different origin: In Neutron Star matter, the non-homogeneous structures arise from a competition between nuclear and Coulomb interactions while for ideal nuclear matter they emerge from finite (yet not “small”) size effects. The role of periodic boundary conditions and finite size effects in Neutron Star matter simulations are reexamined.
Analysis on long-term perspectives of sustainable nuclear energy towards global warming protection
International Nuclear Information System (INIS)
Yamazawa, M.; Ichimura, E.; Shibata, Y.; Kobayashi, K.; Wajima, T.
1998-01-01
Study of long-term perspectives of the nuclear power generation was made from the point of views of both CO 2 emission constraints and sustainability of nuclear energy. To this end, STREAM (Semi-empirical TRiple E Analysis Model) program, as a social model, has been developed by Tokyo Electric Power Co. and Hitachi, Ltd. Using this program, long-term world demands of primary and nuclear energy were deduced, in view of the protection against the global warming due to the CO 2 gas accumulation. The inevitable conclusion has been drawn that nuclear energy plays an indispensable role in the reduction of green house effect. Evaluations were then made on conditions that the nuclear power system would be the long-term major sustainable energy source. (author)
International Nuclear Information System (INIS)
Besson, Ugo; De Ambrosis, Anna; Mascheretti, Paolo
2010-01-01
We present a teaching module dealing with the thermal effects of interaction between radiation and matter, the infrared emission of bodies and the greenhouse effect devoted to university level and teacher education. The module stresses the dependence of the optical properties of materials (transparency, absorptivity and emissivity) on radiation frequency, as a result of interaction between matter and radiation. Multiple experiences are suggested to favour a progressive construction of knowledge on the physical aspects necessary to understand the greenhouse effect and global warming. Some results obtained with university students are briefly reported.
Energy Technology Data Exchange (ETDEWEB)
Besson, Ugo; De Ambrosis, Anna; Mascheretti, Paolo [Department of Physics ' A Volta' , University of Pavia, Via A Bassi 6, 27100 Pavia (Italy)], E-mail: ugo.besson@unipv.it, E-mail: anna.deambrosisvigna@unipv.it
2010-03-15
We present a teaching module dealing with the thermal effects of interaction between radiation and matter, the infrared emission of bodies and the greenhouse effect devoted to university level and teacher education. The module stresses the dependence of the optical properties of materials (transparency, absorptivity and emissivity) on radiation frequency, as a result of interaction between matter and radiation. Multiple experiences are suggested to favour a progressive construction of knowledge on the physical aspects necessary to understand the greenhouse effect and global warming. Some results obtained with university students are briefly reported.
Pion absorption in excited nuclear matter
International Nuclear Information System (INIS)
Schmidt, H.R.; Albrecht, R.; Bock, R.; Gutbrod, H.H.; Kolb, B.W.; Lund, I.; Awes, T.C.; Baktash, C.; Ferguson, R.L.; Lee, I.Y.; Plasil, F.; Saini, S.; Tincknell, M.; Young, G.R.; Beckmann, P.; Berger, F.; Clewing, G.; Dragon, L.; Glasow, R.; Kampert, K.H.; Peitzmann, T.; Purschke, M.; Santo, R.; Claesson, G.; Eklund, A.; Garpman, S.; Gustafsson, H.A.; Idh, J.; Oskarsson, A.; Otterlund, I.; Persson, S.; Stenlund, E.; Franz, A.; Jacobs, P.; Poskanzer, A.M.; Ritter, H.G.; Kristiansson, P.; Loehner, H.; Obenshain, F.E.; Sorensen, S.P.; Siemiarczuk, T.
1992-02-01
The target dependence and azimuthal correlations of protons and plons are investigated for pA reactions at 4.9, 60 and 200 GeV. The experimental observations can be understood qualitatively under the assumption that pions are absorbed in excited target spectator matter. (orig.)
$J/\\Psi$ mass shift in nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Gastao Krein, Anthony Thomas, Kazuo Tsushima
2011-02-01
The $J/\\Psi$ mass shift in cold nuclear matter is computed using an effective Lagrangian approach. The mass shift is computed by evaluating $D$ and $D^*$ meson loop contributions to the $J/\\Psi$ self-energy employing medium-modified meson masses. The modification of the $D$ and $D^*$ masses in nuclear matter is obtained using the quark-meson coupling model. The loop integrals are regularized with dipole form factors and the sensitivity of the results to the values of form-factor cutoff masses is investigated. The $J/\\Psi$ mass shift arising from the modification of the $D$ and $D^*$ loops at normal nuclear matter density is found to range from $-16$~MeV to $-24$~MeV under a wide variation of values of the cutoff masses. Experimental perspectives for the formation of a bound state of $J/\\Psi$ to a nucleus are investigated.
Quark-Meson-Coupling (QMC) model for finite nuclei, nuclear matter and beyond
Guichon, P. A. M.; Stone, J. R.; Thomas, A. W.
2018-05-01
The Quark-Meson-Coupling model, which self-consistently relates the dynamics of the internal quark structure of a hadron to the relativistic mean fields arising in nuclear matter, provides a natural explanation to many open questions in low energy nuclear physics, including the origin of many-body nuclear forces and their saturation, the spin-orbit interaction and properties of hadronic matter at a wide range of densities up to those occurring in the cores of neutron stars. Here we focus on four aspects of the model (i) a full comprehensive survey of the theory, including the latest developments, (ii) extensive application of the model to ground state properties of finite nuclei and hypernuclei, with a discussion of similarities and differences between the QMC and Skyrme energy density functionals, (iii) equilibrium conditions and composition of hadronic matter in cold and warm neutron stars and their comparison with the outcome of relativistic mean-field theories and, (iv) tests of the fundamental idea that hadron structure changes in-medium.
Equation of state of nuclear matter of nucleons and dibaryons
International Nuclear Information System (INIS)
Mrowczynski, St.
1985-01-01
The nuclear matter is considered consisting of nucleons and dibaryons, i.e. elementary particles of double baryon charge. The equation of state of such matter at zero temperature is found. The ideal gas approximation is considered and then the role of interaction is discussed which is included by means of delta-like potential. The peculiarities and possible phisical consequences of the equation of state are considered
Importance of finite-temperature exchange correlation for warm dense matter calculations.
Karasiev, Valentin V; Calderín, Lázaro; Trickey, S B
2016-06-01
The effects of an explicit temperature dependence in the exchange correlation (XC) free-energy functional upon calculated properties of matter in the warm dense regime are investigated. The comparison is between the Karasiev-Sjostrom-Dufty-Trickey (KSDT) finite-temperature local-density approximation (TLDA) XC functional [Karasiev et al., Phys. Rev. Lett. 112, 076403 (2014)PRLTAO0031-900710.1103/PhysRevLett.112.076403] parametrized from restricted path-integral Monte Carlo data on the homogeneous electron gas (HEG) and the conventional Monte Carlo parametrization ground-state LDA XC [Perdew-Zunger (PZ)] functional evaluated with T-dependent densities. Both Kohn-Sham (KS) and orbital-free density-functional theories are used, depending upon computational resource demands. Compared to the PZ functional, the KSDT functional generally lowers the dc electrical conductivity of low-density Al, yielding improved agreement with experiment. The greatest lowering is about 15% for T=15 kK. Correspondingly, the KS band structure of low-density fcc Al from the KSDT functional exhibits a clear increase in interband separation above the Fermi level compared to the PZ bands. In some density-temperature regimes, the deuterium equations of state obtained from the two XC functionals exhibit pressure differences as large as 4% and a 6% range of differences. However, the hydrogen principal Hugoniot is insensitive to the explicit XC T dependence because of cancellation between the energy and pressure-volume work difference terms in the Rankine-Hugoniot equation. Finally, the temperature at which the HEG becomes unstable is T≥7200 K for the T-dependent XC, a result that the ground-state XC underestimates by about 1000 K.
Modified quark-meson coupling model for nuclear matter
International Nuclear Information System (INIS)
Jin, X.; Jennings, B.K.
1996-01-01
The quark-meson coupling model for nuclear matter, which describes nuclear matter as nonoverlapping MIT bags bound by the self-consistent exchange of scalar and vector mesons, is modified by introducing medium modification of the bag constant. We model the density dependence of the bag constant in two different ways: One invokes a direct coupling of the bag constant to the scalar meson field, and the other relates the bag constant to the in-medium nucleon mass. Both models feature a decreasing bag constant with increasing density. We find that when the bag constant is significantly reduced in nuclear medium with respect to its free-space value, large canceling isoscalar Lorentz scalar and vector potentials for the nucleon in nuclear matter emerge naturally. Such potentials are comparable to those suggested by relativistic nuclear phenomenology and finite-density QCD sum rules. This suggests that the reduction of bag constant in nuclear medium may play an important role in low- and medium-energy nuclear physics. copyright 1996 The American Physical Society
Nuclear physics: the core of matter, the fuel of stars
International Nuclear Information System (INIS)
Schiffer, J.P.
1999-01-01
Dramatic progress has been made in all branches of physics since the National Research Council's 1986 decadal survey of the field. The Physics in a New Era series explores these advances and looks ahead to future goals. The series includes assessments of the major subfields and reports on several smaller subfields, and preparation has begun on an overview volume on the unity of physics, its relationships to other fields, and its contributions to national needs. Nuclear Physics is the latest volume of the series. The book describes current activity in understanding nuclear structure and symmetries, the behavior of matter at extreme densities, the role of nuclear physics in astrophysics and cosmology, and the instrumentation and facilities used by the field. It makes recommendations on the resources needed for experimental and theoretical advances in the coming decade. Nuclear physics addresses the nature of matter making up 99.9 percent of the mass of our everyday world. It explores the nuclear reactions that fuel the stars, including our Sun, which provides the energy for all life on Earth. The field of nuclear physics encompasses some 3,000 experimental and theoretical researchers who work at universities and national laboratories across the United States, as well as the experimental facilities and infrastructure that allow these researchers to address the outstanding scientific questions facing us. This report provides an overview of the frontiers of nuclear physics as we enter the next millennium, with special attention to the state of the science in the United States.The current frontiers of nuclear physics involve fundamental and rapidly evolving issues. One is understanding the structure and behavior of strongly interacting matter in terms of its basic constituents, quarks and gluons, over a wide range of conditions - from normal nuclear matter to the dense cores of neutron stars, and to the Big Bang that was the birth of the universe. Another is to describe
Eliciting public preference for nuclear energy against the backdrop of global warming
Energy Technology Data Exchange (ETDEWEB)
Liao, Shu-Yi; Tseng, Wei-Chun; Chen, Chi-Chung [Department of Applied Economics, National Chung-Hsing University, 250 Kuo Kuang Road, Taichung 40246 (China)
2010-11-15
One of the most important issues related to sustainability is to reduce the use of fossil fuels due to the reduction in greenhouse gases (GHG) emission. Nuclear power results in low carbon emissions and is thus important to mitigating the adverse effects of global warming and climate change. However, the downside of nuclear power cannot be overlooked, and consequently nuclear power is a controversial issue in many countries around the world. Thus an important question concerns how people should support nuclear power. Do the climate and energy security benefits of nuclear power outweigh its risks and costs? Therefore, we use a modified double-bounded contingent valuation model to explore the attitudes and the willingness to pay (WTP) of a country in order to demonstrate its implications for policy. We confirm that supporters and opponents of nuclear power are balanced both in terms of their numbers and in terms of their WTP. The policy implication is that people do not support any dramatic increase or reduction in nuclear power, and that nuclear power should still be an important means of generating electricity in Taiwan. The current share of nuclear power in electricity generation of 20% should be maintained in the near future. (author)
Energy-range relations for hadrons in nuclear matter
Strugalski, Z.
1985-01-01
Range-energy relations for hadrons in nuclear matter exist similarly to the range-energy relations for charged particles in materials. When hadrons of GeV kinetic energies collide with atomic nuclei massive enough, events occur in which incident hadron is stopped completely inside the target nucleus without causing particle production - without pion production in particular. The stoppings are always accompanied by intensive emission of nucleons with kinetic energy from about 20 up to about 400 MeV. It was shown experimentally that the mean number of the emitted nucleons is a measure of the mean path in nuclear matter in nucleons on which the incident hadrons are stopped.
Thermal properties of nuclear matter under the periodic boundary condition
International Nuclear Information System (INIS)
Otuka, Naohiko; Ohnishi, Akira
1999-01-01
We present the thermal properties of nuclear matter under the periodic boundary condition by the use of our hadronic nucleus-nucleus cascade model (HANDEL) which is developed to treat relativistic heavy-ion collisions from BNL-AGS to CERN-SPS. We first show some results of p-p scattering calculation in our new version which is improved in order to treat isospin ratio and multiplicity more accurately. We then display the results of calculation of nuclear matter with baryon density ρ b = 0.77 fm 3 at some energy densities. Time evolution of particle abundance and temperature are shown. (author)
Lectures notes on phase transformations in nuclear matter
López, Jorge A
2000-01-01
The atomic nucleus, despite of being one of the smallest objects found in nature, appears to be large enough to experience phase transitions. The book deals with the liquid and gaseous phases of nuclear matter, as well as with the experimental routes to achieve transformation between them.Theoretical models are introduced from the ground up and with increasing complexity to describe nuclear matter from a statistical and thermodynamical point of view. Modern critical phenomena, heavy ion collisions and computational techniques are presented while establishing a linkage to experimental data.The
Charge symmetry breaking nuclear forces and the properties of nuclear matter
International Nuclear Information System (INIS)
Haensel, P.
1977-01-01
The charge symmetry breaking (CSB) component of the nuclear forces yields the charge asymmetric term Esub(a)(N-Z)/A in the nuclear binding energy of nuclear matter. Calculation performed with several models of the CSB nuclear forces, and accounting for the strong short-range two-body correlations, gives Esub(a) approximately -0.2 MeV at the normal nuclear density. The charge asymmetry of the effective nucleon-nucleon interaction is determined primarily by the CSB nuclear forces at the neutron excess, observed in finite nuclei. The exclusion principle and dispersion (self-consistency) effects of the nuclear medium decrease this charge asymmetry. (author)
α particles and the ''pasta'' phase in nuclear matter
International Nuclear Information System (INIS)
Avancini, S. S.; Barros, C. C. Jr.; Menezes, D. P.; Providencia, C.
2010-01-01
The effects of the α particles in nuclear matter at low densities are investigated within three different parametrizations of relativistic models at finite temperature. Both homogeneous and inhomogeneous matter (pasta phase) are described for neutral nuclear matter with fixed proton fractions and stellar matter subject to β equilibrium and trapped neutrinos. In homogeneous matter, α particles are present only at densities below 0.02 fm -3 and their presence decreases with increase of the temperature and, for a fixed temperature, the α particle fraction decreases for smaller proton fractions. A repulsive interaction is important to mimic the dissolution of the clusters in homogeneous matter. The effect of the α particles on the pasta structure is very small except close to the critical temperatures and/or proton fractions, when it may still predict a pasta phase while no pasta phase would occur in the absence of light clusters. It is shown that for densities above 0.01 fm 3 the α-particle fraction in the pasta phase is much larger than that in homogeneous matter.
Quark distributions in nuclear matter and the EMC effect
Energy Technology Data Exchange (ETDEWEB)
Mineo, H.; Bentz, W. E-mail: bentz@keyaki.cc.u-tokai.ac.jp; Ishii, N.; Thomas, A.W.; Yazaki, K
2004-05-03
Quark light cone momentum distributions in nuclear matter and the structure function of a bound nucleon are investigated in the framework of the Nambu-Jona-Lasinio model. This framework describes the nucleon as a relativistic quark-diquark state, and the nuclear matter equation of state by using the mean field approximation. The scalar and vector mean fields in the nuclear medium couple to the quarks in the nucleon and their effect on the spin independent nuclear structure function is investigated in detail. Special emphasis is placed on the important effect of the vector mean field and on a formulation which guarantees the validity of the number and momentum sum rules from the outset.
International Nuclear Information System (INIS)
Kuzio de Naray, Rachel; Martinez, Gregory D.; Bullock, James S.; Kaplinghat, Manoj
2010-01-01
Warm dark matter (WDM) and self-interacting dark matter (SIDM) are often motivated by the inferred cores in the dark matter halos of low surface brightness (LSB) galaxies. We test thermal WDM, non-thermal WDM, and SIDM using high-resolution rotation curves of nine LSB galaxies. We fit these dark matter models to the data and determine the halo core radii and central densities. While the minimum core size in WDM models is predicted to decrease with halo mass, we find that the inferred core radii increase with halo mass and also cannot be explained with a single value of the primordial phase-space density. Moreover, if the core size is set by WDM particle properties, then even the smallest cores we infer would require primordial phase-space density values that are orders of magnitude smaller than lower limits obtained from the Lyα forest power spectra. We also find that the dark matter halo core densities vary by a factor of about 30 from system to system while showing no systematic trend with the maximum rotation velocity of the galaxy. This strongly argues against the core size being directly set by large self-interactions (scattering or annihilation) of dark matter. We therefore conclude that the inferred cores do not provide motivation to prefer WDM or SIDM over other dark matter models.
Supernovae and high density nuclear matter
International Nuclear Information System (INIS)
Kahana, S.
1986-01-01
The role of the nuclear equation of state (EOS) in producing prompt supernova explosions is examined. Results of calculations of Baron, Cooperstein, and Kahana incorporating general relativity and a new high density EOS are presented, and the relevance of these calculations to laboratory experiments with heavy ions considered. 31 refs., 6 figs., 2 tabs
Supernovae and high density nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Kahana, S.
1986-01-01
The role of the nuclear equation of state (EOS) in producing prompt supernova explosions is examined. Results of calculations of Baron, Cooperstein, and Kahana incorporating general relativity and a new high density EOS are presented, and the relevance of these calculations to laboratory experiments with heavy ions considered. 31 refs., 6 figs., 2 tabs.
Instability in relativistic mean-field theories of nuclear matter
International Nuclear Information System (INIS)
Friman, B.L.; Henning, P.A.
1988-01-01
We investigate the stability of the nuclear matter ground state with respect to small-perturbations of the meson fields in relativistic mean-field theories. The popular σ-ω model is shown to have an instability at about twice the nuclear density, which gives rise to a new ground state with periodic spin alignment. Taking into account the contributions of the Dirac sea properly, this instability vanishes. Consequences for relativistic heavy-ion-collisions are discussed briefly. (orig.)
Instability in relativistic mean-field theories of nuclear matter
International Nuclear Information System (INIS)
Friman, B.L.; Henning, P.A.
1988-01-01
We investigate the stability of the nuclear matter ground state with respect to small perturbations of the meson fields in relativistic mean-field theories. The popular σ-ω model is shown to have an instability at about twice the nuclear density, which gives rise to a new ground state with periodic spin alignment. Taking into account the contributions of the Dirac sea properly, this instability vanishes. Consequences for relativistic heavy-ion collisions are discussed briefly. (orig.)
Measurements Matter in Nuclear Safeguards & Security
International Nuclear Information System (INIS)
Aregbe, Y.; Jakopic, R.; Richter, S.; Schillebeeckx, P.; Hult, M.
2015-01-01
The deliverable of any laboratory is a measurement result with stated uncertainty and traceability (ISO/IEC 17025: 2005). Measurement results, particularly in safeguards, have to be accurate, comparable and traceable to a stated reference, preferably to the SI. Results provided by operator-, safeguards- or network laboratories have to be in compliance with specific quality goals for nuclear material and environmental sample analysis. Metrological quality control tools are prerequisites to build up confidence in measurement results that have to be translated into meaningful safeguards conclusions or to demonstrate conformity of findings with declared processes. The European Commission—Joint Research Centre (EC–JRC) has dedicated facilities, laboratories and projects to provide certified nuclear reference materials (CRM), to develop reference methods and to organize inter-laboratory comparisons (ILC) in compliance with ISO Guide 34, ISO17025 and ISO17043, including respective training. Recent examples are: – cooperation with the JAEA to investigate on the application of Neutron Resonance Densitometry (NRD) to quantify the amount of special nuclear material in particlelike debris of melted fuel as formed in the nuclear accident in Fukushima – training in metrology and gamma-ray spectrometry for EURATOM safeguards inspectors – development of uranium reference particle standards under a new EC support task to the IAEA. Currently, the JRC puts major efforts in producing CRMs and conformity assessment tools for “age-dating” of uranium and plutonium samples. They are needed for method validation in determining the date of the last chemical separation of uranium or plutonium from their daughter nuclides. These type of CRMs are not only needed in nuclear safeguards and forensics, but could support in the future a possible new type of “verification mechanism” as part of the Fissile Material Cut-off Treaty (FMCT), since measurements and measurement standards
Fujii, Yoshiaki
2011-04-01
This study suggests that the cause of the stagnation in global warming in the mid 20th century was the atmospheric nuclear explosions detonated between 1945 and 1980. The estimated GST drop due to fine dust from the actual atmospheric nuclear explosions based on the published simulation results by other researchers (a single column model and Atmosphere-Ocean General Circulation Model) has served to explain the stagnation in global warming. Atmospheric nuclear explosions can be regarded as full-scale in situ tests for nuclear winter. The non-negligible amount of GST drop from the actual atmospheric explosions suggests that nuclear winter is not just a theory but has actually occurred, albeit on a small scale. The accuracy of the simulations of GST by IPCC would also be improved significantly by introducing the influence of fine dust from the actual atmospheric nuclear explosions into their climate models; thus, global warming behavior could be more accurately predicted.
Energy Technology Data Exchange (ETDEWEB)
Schoof, Tim
2017-03-08
diagonalization method. Benchmark results are presented which reveal large errors of the Hartree-Fock approximation in open shell configurations even for weak coupling strengths and a significant deviation of multi-level blocking PIMC data in the complete basis set limit. The application of the CPIMC method to the warm dense homogeneous electron gas (HEG) quantifies the accuracy of recently published restricted PIMC (RPIMC) results which have been the basis for the construction of exchange-correlation free energy functionals to be used in finite-temperature density functional theory calculations of warm dense matter. It is shown that the errors of the RPIMC data exceed 10 % at intermediate densities. Additionally, highly accurate data for the exchange-correlation energy at high densities, which are inaccessible by the RPIMC method, are provided in this work. These results are useful to significantly increase the quality of future exchange-correlation functionals for finite-temperature applications. The benchmark results of this work have already been used in the development of other methods such as density-matrix QMC. In particular, thorough comparisons have been crucial for the successful verification of the accuracy of the permutation blocking PIMC method, which extends PIMC calculations to much higher densities and degeneracies. The combination of the complementary CPIMC and PBPIMC methods allows for an almost complete description of the HEG at finite temperatures in the thermodynamic limit.
Three-dimensional structure of low-density nuclear matter
International Nuclear Information System (INIS)
Okamoto, Minoru; Maruyama, Toshiki; Yabana, Kazuhiro; Tatsumi, Toshitaka
2012-01-01
We numerically explore the pasta structures and properties of low-density nuclear matter without any assumption on the geometry. We observe conventional pasta structures, while a mixture of the pasta structures appears as a metastable state at some transient densities. We also discuss the lattice structure of droplets.
Three-dimensional calculation of inhomogeneous nuclear matter
International Nuclear Information System (INIS)
Okamoto, Minoru; Maruyama, Toshiki; Yabana, Kazuhiro; Tatsumi, Toshitaka
2012-01-01
We numerically explore the pasta structures and properties of low-density symmetric nuclear matter without any assumption on the geometry. We observe conventional pasta structures, while a mixture of the pasta appears as a meta-stable state at some transient densities. We also analyze the lattice structure of droplets.
Three-dimensional calculation of inhomogeneous nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Okamoto, Minoru; Maruyama, Toshiki; Yabana, Kazuhiro; Tatsumi, Toshitaka [Graduate School of Pure and Applied Science, University of Tsukuba (Japan); Advanced Science Research Center, Japan Atomic Energy Agency (Japan); Graduate School of Pure and Applied Science, University of Tsukuba (Japan); Department of Physics, Kyoto University (Japan)
2012-11-12
We numerically explore the pasta structures and properties of low-density symmetric nuclear matter without any assumption on the geometry. We observe conventional pasta structures, while a mixture of the pasta appears as a meta-stable state at some transient densities. We also analyze the lattice structure of droplets.
Three-dimensional structure of low-density nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Okamoto, Minoru, E-mail: okamoto@nucl.ph.tsukuba.ac.jp [Graduate School of Pure and Applied Science, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8571 (Japan); Advanced Science Research Center, Japan Atomic Energy Agency, Shirakata Shirane 2-4, Tokai, Ibaraki 319-1195 (Japan); Maruyama, Toshiki, E-mail: maruyama.toshiki@jaea.go.jp [Advanced Science Research Center, Japan Atomic Energy Agency, Shirakata Shirane 2-4, Tokai, Ibaraki 319-1195 (Japan); Graduate School of Pure and Applied Science, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8571 (Japan); Yabana, Kazuhiro, E-mail: yabana@nucl.ph.tsukuba.ac.jp [Graduate School of Pure and Applied Science, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8571 (Japan); Center of Computational Sciences, University of Tsukuba, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8571 (Japan); Tatsumi, Toshitaka, E-mail: tatsumi@ruby.scphys.kyoto-u.ac.jp [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan)
2012-07-09
We numerically explore the pasta structures and properties of low-density nuclear matter without any assumption on the geometry. We observe conventional pasta structures, while a mixture of the pasta structures appears as a metastable state at some transient densities. We also discuss the lattice structure of droplets.
Binding Energy and Compression Modulus of Infinite Nuclear Matter ...
African Journals Online (AJOL)
... MeV at the normal nuclear matter saturation density consistent with the best available density-dependent potentials derived from the G-matrix approach. The results of the incompressibility modulus, k∞ is in excellent agreement with the results of other workers. Journal of the Nigerian Association of Mathematical Physics, ...
QUANTUM TRANSPORT-THEORY OF NUCLEAR-MATTER
BOTERMANS, W; MALFLIET, R
1990-01-01
Quantum kinetic equations are derived using the Keldysh Green's function formalism to describe non-equilibrium processes in nuclear matter and nucleus-nucleus collisions. A general transport equation is proposed which includes energy spreading effects. We discuss a number of specific kinetic
The symmetry energy in nuclei and in nuclear matter
Van Isacker, P.; Dieperink, A. E. L.
2006-01-01
We discuss to what extent information on ground-state properties of finite nuclei (energies and radii) can be used to obtain constraints on the symmetry energy in nuclear matter and its dependence on the density. The starting point is a generalized Weizsacker formula for ground-state energies. In
The symmetry energy in nuclei and in nuclear matter
Dieperink, A. E. L.; Van Isacker, P.
We discuss to what extent information on ground-state properties of finite nuclei ( energies and radii) can be used to obtain constraints on the symmetry energy in nuclear matter and its dependence on the density. The starting point is a generalized Weizsacker formula for ground-state energies. In
Nuclear symmetry energy and stability of matter in neutron stars
International Nuclear Information System (INIS)
Kubis, Sebastian
2007-01-01
It is shown that the nuclear symmetry energy is the key quantity in the stability consideration in neutron star matter. The symmetry energy controls the position of crust-core transition and also may lead to new effects in the inner core of neutron star
Nuclear matter equation of state and σ-meson parameters
Indian Academy of Sciences (India)
We try to determine phenomenologically the extent of in-medium modification of -meson parameters so that the saturation observables of the nuclear matter equation of state (EOS) are reproduced. To calculate the EOS we have used Brueckner–Bethe–Goldstone formalism with Bonn potential as two-body interaction.
Charm and Hidden Charm Scalar Resonances in Nuclear Matter
Tolos, Laura; Molina, Raquel; Gamermann, Daniel; Oset, Eulogio
2009-01-01
We study the properties of the scalar charm resonances D(s0)(2317) and D(0)(2400), and the theoretical hidden charm state X(3700) in nuclear matter. We find that for the D(s0)(2317) and X(3700) resonances, with negligible and small width at zero density, respectively, the width becomes about 100 MeV
Spin polarized states in strongly asymmetric nuclear matter
International Nuclear Information System (INIS)
Isayev, A.A.; Yang, J.
2004-01-01
The possibility of appearance of spin polarized states in strongly asymmetric nuclear matter is analyzed within the framework of a Fermi liquid theory with the Skyrme effective interaction. The zero temperature dependence of the neutron and proton spin polarization parameters as functions of density is found for SLy4 and SLy5 effective forces. It is shown that at some critical density strongly asymmetric nuclear matter undergoes a phase transition to the state with the oppositely directed spins of neutrons and protons while the state with the same direction of spins does not appear. In comparison with neutron matter, even small admixture of protons strongly decreases the threshold density of spin instability. It is clarified that protons become totally polarized within a very narrow density domain while the density profile of the neutron spin polarization parameter is characterized by the appearance of long tails near the transition density
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.
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
Nuclear matter from effective quark-quark interaction.
Baldo, M; Fukukawa, K
2014-12-12
We study neutron matter and symmetric nuclear matter with the quark-meson model for the two-nucleon interaction. The Bethe-Bruckner-Goldstone many-body theory is used to describe the correlations up to the three hole-line approximation with no extra parameters. At variance with other nonrelativistic realistic interactions, the three hole-line contribution turns out to be non-negligible and to have a substantial saturation effect. The saturation point of nuclear matter, the compressibility, the symmetry energy, and its slope are within the phenomenological constraints. Since the interaction also reproduces fairly well the properties of the three-nucleon system, these results indicate that the explicit introduction of the quark degrees of freedom within the considered constituent quark model is expected to reduce the role of three-body forces.
Comparative study of three-nucleon potentials in nuclear matter
Lovato, Alessandro; Benhar, Omar; Fantoni, Stefano; Schmidt, Kevin E.
2012-02-01
A new generation of local three-body potentials providing an excellent description of the properties of light nuclei, as well as of the neutron-deuteron doublet scattering length, has been recently derived. We have performed a comparative analysis of the equations of state of both pure neutron matter (PNM) and symmetric nuclear matter (SNM) at zero temperature obtained using these models of three-nucleon forces. In particular, we have carried out both variational and auxiliary field diffusion Monte Carlo calculations of the equation of state of PNM, while in the case of SNM we have only the variational approach has been considered. None of the considered potentials simultaneously explains the empirical equilibrium density and binding energy of symmetric nuclear matter. However, two of them provide reasonable values of the saturation density. The ambiguity concerning the treatment of the contact term of the chiral inspired potentials is discussed.
Warm Dark Matter Sterile Neutrinos in Electron Capture and Beta Decay Spectra
Directory of Open Access Journals (Sweden)
O. Moreno
2016-01-01
Full Text Available We briefly review the motivation to search for sterile neutrinos in the keV mass scale, as dark matter candidates, and the prospects to find them in beta decay or electron capture spectra, with a global perspective. We describe the fundamentals of the neutrino flavor-mass eigenstate mismatch that opens the possibility of detecting sterile neutrinos in such ordinary nuclear processes. Results are shown and discussed for the effect of heavy neutrino emission in electron capture in Holmium 163 and in two isotopes of Lead, 202 and 205, as well as in the beta decay of Tritium. We study the deexcitation spectrum in the considered cases of electron capture and the charged lepton spectrum in the case of Tritium beta decay. For each of these cases, we define ratios of integrated transition rates over different regions of the spectrum under study and give new results that may guide and facilitate the analysis of possible future measurements, paying particular attention to forbidden transitions in Lead isotopes.
Nonlinear mean field theory for nuclear matter and surface properties
International Nuclear Information System (INIS)
Boguta, J.; Moszkowski, S.A.
1983-01-01
Nuclear matter properties are studied in a nonlinear relativistic mean field theory. We determine the parameters of the model from bulk properties of symmetric nuclear matter and a reasonable value of the effective mass. In this work, we stress the nonrelativistic limit of the theory which is essentially equivalent to a Skyrme hamiltonian, and we show that most of the results can be obtained, to a good approximation, analytically. The strength of the required parameters is determined from the binding energy and density of nuclear matter and the effective nucleon mass. For realistic values of the parameters, the nonrelativistic approximation turns out to be quite satisfactory. Using reasonable values of the parameters, we can account for other key properties of nuclei, such as the spin-orbit coupling, surface energy, and diffuseness of the nuclear surface. Also the energy dependence of the nucleon-nucleus optical model is accounted for reasonably well except near the Fermi surface. It is found, in agreement with empirical results, that the Landau parameter F 0 is quite small in normal nuclear matter. Both density dependence and momentum dependence of the NN interaction, but especially the former, are important for nuclear saturation. The required scalar and vector coupling constants agree fairly well with those obtained from analyses of NN scattering phase shifts with one-boson-exchange models. The mean field theory provides a semiquantitative justification for the weak Skyrme interaction in odd states. The strength of the required nonlinear term is roughly consistent with that derived using a new version of the chiral mean field theory in which the vector mass as well as the nucleon mass is generated by the sigma-field. (orig.)
Variational theory of nuclear and neutron matter
International Nuclear Information System (INIS)
Pandharipande, V.R.; Wiringa, R.B.
1989-06-01
In these lectures we will discuss attempts to solve the A = 3 to ∞ nuclear many-body problems with the variational method. We choose the form of a variational wave function Χ v (1, 2 hor-ellipsis A) to describe the ground state. The Χ v and the ground-state energy E v are obtained by minimizing E v = left-angle Χ v |H|Χ v right-angle/left-angle Χ v |Χ v right-angle with respect to variations in Χ v . If the form of the variational wave function is chosen properly we can expect Χ v ∼ Χ 0 and E v ∼ E 0 where Χ 0 and E 0 are the exact ground-state wave function and energy. In general E v ≥ E 0 in variational calculations. 63 refs., 11 figs
Nuclear power and global warming: a first cost-benefit calculation
International Nuclear Information System (INIS)
Hope, C.
1994-01-01
This paper investigates the costs and benefits of a modest nuclear power programme in the European Union to combat the threat of global warming. The nuclear programme is found to bring a double benefit. The first and more obvious benefit is that the economic impacts of global warming are reduced. The second benefit is counter-intuitive; most people would expect it to be a cost. It comes from the stimulus to the economy from the construction of the nuclear plant, which, with the recycling of carbon tax revenues, offsets its construction and operating costs, and may even cause consumers' expenditure to rise. Calculations in this paper show that over the period to 2100 the mean net present value of the first benefit is 6 billion European Currency Units (ECU; 1 ECU is about Dollars 1), while the second benefit has a mean net present value of 159 billion ECU. However both benefits, particularly the second, are still very uncertain, to the extent that even their sign is not yet definitely established. (author)
Climate Change, Nuclear Power and Nuclear Proliferation: Magnitude Matters
Energy Technology Data Exchange (ETDEWEB)
Robert J. Goldston
2010-03-03
Integrated energy, environment and economics modeling suggests electrical energy use will increase from 2.4 TWe today to 12 TWe in 2100. It will be challenging to provide 40% of this electrical power from combustion with carbon sequestration, as it will be challenging to provide 30% from renewable energy sources. Thus nuclear power may be needed to provide ~30% by 2100. Calculations of the associated stocks and flows of uranium, plutonium and minor actinides indicate that the proliferation risks at mid-century, using current light-water reactor technology, are daunting. There are institutional arrangements that may be able to provide an acceptable level of risk mitigation, but they will be difficult to implement. If a transition is begun to fast-spectrum reactors at mid-century, without a dramatic change in the proliferation risks of such systems, at the end of the century proliferation risks are much greater, and more resistant to mitigation. The risks of nuclear power should be compared with the risks of the estimated 0.64oC long-term global surface-average temperature rise predicted if nuclear power were replaced with coal-fired power plants without carbon sequestration. Fusion energy, if developed, would provide a source of nuclear power with much lower proliferation risks than fission.
Climate Change, Nuclear Power and Nuclear Proliferation: Magnitude Matters
International Nuclear Information System (INIS)
Goldston, Robert J.
2010-01-01
Integrated energy, environment and economics modeling suggests electrical energy use will increase from 2.4 TWe today to 12 TWe in 2100. It will be challenging to provide 40% of this electrical power from combustion with carbon sequestration, as it will be challenging to provide 30% from renewable energy sources. Thus nuclear power may be needed to provide ∼30% by 2100. Calculations of the associated stocks and flows of uranium, plutonium and minor actinides indicate that the proliferation risks at mid-century, using current light-water reactor technology, are daunting. There are institutional arrangements that may be able to provide an acceptable level of risk mitigation, but they will be difficult to implement. If a transition is begun to fast-spectrum reactors at mid-century, without a dramatic change in the proliferation risks of such systems, at the end of the century proliferation risks are much greater, and more resistant to mitigation. The risks of nuclear power should be compared with the risks of the estimated 0.64 C long-term global surface-average temperature rise predicted if nuclear power were replaced with coal-fired power plants without carbon sequestration. Fusion energy, if developed, would provide a source of nuclear power with much lower proliferation risks than fission.
Variational method for infinite nuclear matter with noncentral forces
International Nuclear Information System (INIS)
Takano, M.; Yamada, M.
1998-01-01
Approximate energy expressions are proposed for infinite zero-temperature nuclear matter by taking into account noncentral forces. They are explicitly expressed as functionals of spin- (isospin-) dependent radial distribution functions, tensor distribution functions and spin-orbit distribution functions, and can be used conveniently in the variational method. A notable feature of these expressions is that they automatically guarantee the necessary conditions on the spin-isospin-dependent structure functions. The Euler-Lagrange equations are derived from these energy expressions and numerically solved for neutron matter and symmetric nuclear matter. The results show that the noncentral forces bring down the total energies too much with too dense saturation densities. Since the main reason for these undesirable results seems to be the long tails of the noncentral distribution functions, an effective theory is proposed by introducing a density-dependent damping function into the noncentral potentials to suppress the long tails of the non-central distribution functions. By adjusting the value of a parameter included in the damping function, we can reproduce the saturation point (both the energy and density) of symmetric nuclear matter with the Hamada-Johnston potential. (Copyright (1998) World Scientific Publishing Co. Pte. Ltd)
Energy Technology Data Exchange (ETDEWEB)
Khvorostyanov, D.V.; Ciais, G. (Laboratoire des Sciences du Climat et l' Environnement, Saclay (France)); Krinner, G. (Laboratoire de Glaciologie et Geophysique de l' Environnement, St Martin d' Heres (France)). e-mail: Dimitry.Khvorostiyanov@lsce.ipsl.fr; Heimann, M. (Max-Planck Inst. of Biogeochemistry, Jena (DE)); Zimov, S.A. (Northeast Science Station, Cherskii (RU))
2008-07-01
We constructed a new model to study the sensitivity of permafrost carbon stocks to future climate warming. The one-dimensional model solves an equation for diffusion of heat penetrating from the overlying atmosphere and takes into account additional in situ heat production by active soil microorganisms. Decomposition of frozen soil organic matter and produced CO{sub 2} and methane fluxes result from an interplay of soil heat conduction and phase transitions, respiration, methanogenesis and methanotrophy processes. Respiration and methanotrophy consume soil oxygen and thus can only develop in an aerated top-soil column. In contrast, methanogenesis is not limited by oxygen and can be sustained within the deep soil, releasing sufficient heat to further thaw in depth the frozen carbon-rich soil organic matter. Heat production that accompanies decomposition and methanotrophy can be an essential process providing positive feedback to atmospheric warming through self-sustaining transformation of initially frozen soil carbon into CO{sub 2} and CH{sub 4}. This supplementary heat becomes crucial, however, only under certain climate conditions. Oxygen limitation to soil respiration slows down the process, so that the mean flux of carbon released during the phase of intense decomposition is more than two times less than without oxygen limitation. Taking into account methanogenesis increases the mean carbon flux by 20%. Part II of this study deals with mobilization of frozen carbon stock in transient climate change scenarios with more elaborated methane module, which makes it possible to consider more general cases with various site configurations. Part I (this manuscript) studies mobilization of 400 GtC carbon stock of the Yedoma in response to a stepwise rapid warming focusing on the role of supplementary heat that is released to the soil during decomposition of organic matter
Pion condensation in a theory consistent with bulk properties of nuclear matter
International Nuclear Information System (INIS)
Glendenning, N.K.
1980-01-01
A relativistic field theory of nuclear matter is solved for the self-consistent field strengths inthe mean-field approximation. The theory is constrained to reproduce the bulk properties of nuclear matter. A weak pion condensate is compatible with this constraint. At least this is encouraging as concerns the possible existence of a new phase of nuclear matter. In contrast, the Lee-Wick density isomer is probably not compatible with the properties of nuclear matter. 3 figures
Variational theory of nuclear and neutron matter
Energy Technology Data Exchange (ETDEWEB)
Pandharipande, V.R.; Wiringa, R.B. (Illinois Univ., Urbana, IL (USA). Dept. of Physics; Argonne National Lab., IL (USA))
1989-06-01
In these lectures we will discuss attempts to solve the A = 3 to {infinity} nuclear many-body problems with the variational method. We choose the form of a variational wave function {Chi}{sub v}(1, 2{hor ellipsis}A) to describe the ground state. The {Chi}{sub v} and the ground-state energy E{sub v} are obtained by minimizing E{sub v} = {l angle}{Chi}{sub v}{vert bar}H{vert bar}{Chi}{sub v}{r angle}/{l angle}{Chi}{sub v}{vert bar}{Chi}{sub v}{r angle} with respect to variations in {Chi}{sub v}. If the form of the variational wave function is chosen properly we can expect {Chi}{sub v} {approx} {Chi}{sub 0} and E{sub v} {approx} E{sub 0} where {Chi}{sub 0} and E{sub 0} are the exact ground-state wave function and energy. In general E{sub v} {ge} E{sub 0} in variational calculations. 63 refs., 11 figs.
Nuclear matter descriptions including quark structure of the hadrons
International Nuclear Information System (INIS)
Huguet, R.
2008-07-01
It is nowadays well established that nucleons are composite objects made of quarks and gluons, whose interactions are described by Quantum chromodynamics (QCD). However, because of the non-perturbative character of QCD at the energies of nuclear physics, a description of atomic nuclei starting from quarks and gluons is still not available. A possible alternative is to construct effective field theories based on hadronic degrees of freedom, in which the interaction is constrained by QCD. In this framework, we have constructed descriptions of infinite nuclear matter in relativistic mean field theories taking into account the quark structure of hadrons. In a first approach, the in medium modifications of mesons properties is dynamically obtained in a Nambu-Jona-Lasinio (NJL) quark model. This modification is taken into account in a relativistic mean field theory based on a meson exchange interaction between nucleons. The in-medium modification of mesons masses and the properties of infinite nuclear matter have been studied. In a second approach, the long and short range contributions to the in-medium modification of the nucleon are determined. The short range part is obtained in a NJL quark model of the nucleon. The long range part, related to pions exchanges between nucleons, has been determined in the framework of Chiral Perturbation theory. These modifications have been used to constrain the couplings of a point coupling relativistic mean field model. A realistic description of the saturation properties of nuclear matter is obtained. (author)
Review of the theory of infinite nuclear matter
International Nuclear Information System (INIS)
Llano, M. de; Tolmachev, V.V.
1975-01-01
Given a two-body force, there seems to be two distinct starting points in the many-body perturbation-theoretic problem of computing the energy per nucleon of infinite (as well as finite) nuclear matter: ordinary Hartree-Fock theory and the Brueckner theory. The former theory, treated almost exclusively with plane-wave solutions, has long-ago fallen into disuse, to yield to the latter, apparently more sophisticated, theory. After a brief outline of many-fermion diagramatic techniques, the Brueckner-Bethe-Goldstone series expansion in terms of the density is discussed as a low density, non-ideal Fermi gas theory, whose convergence is analyzed. A calculation based on particle-hole Green's function techniques shows that a nucleon gas condenses to the liquid phase at about 3% of the empirical nuclear matter saturation density. The analogy between the BBG expansion and the virial expansion for a classical or quantum gas is studied with special emphasis on the apparent impossibility of analytical-continuing the latter gas theory to densities in the liquid regime, as first elucidated by Lee and Yang. It is finally argued that ordinary HF theory may provide a good starting point for the eventual understanding of nuclear matter as it gives (in the finite nuclear problem, at any rate) not only the basic liquid properties of a definite density and a surface but also provides independent-particle aspects, avoiding at the same time the idea of n-body clusters appropriate only for dilute gases. This program has to date not been carried out for infinite nuclear matter, mainly because of insufficient knowledge regarding low-energy, non-plane-wave solutions of the HF equations, in the thermodynamic limit [pt
Climate Change, Nuclear Power and Nuclear Proliferation: Magnitude Matters
International Nuclear Information System (INIS)
Goldston, Robert J.
2011-01-01
Integrated energy, environment and economics modeling suggests that worldwide electrical energy use will increase from 2.4 TWe today to ∼12 TWe in 2100. It will be challenging to provide 40% of this electrical power from combustion with carbon sequestration, as it will be challenging to provide 30% from renewable energy sources derived from natural energy flows. Thus nuclear power may be needed to provide ∼30%, 3600 GWe, by 2100. Calculations of the associated stocks and flows of uranium, plutonium and minor actinides indicate that the proliferation risks at mid-century, using current light-water reactor technology, are daunting. There are institutional arrangements that may be able to provide an acceptable level of risk mitigation, but they will be difficult to implement. If a transition is begun to fast-spectrum reactors at mid-century, without a dramatic change in the proliferation risks of such systems, at the end of the century global nuclear proliferation risks are much greater, and more resistant to mitigation. Fusion energy, if successfully demonstrated to be economically competitive, would provide a source of nuclear power with much lower proliferation risks than fission.
Climate Change, Nuclear Power and Nuclear Proliferation: Magnitude Matters
Energy Technology Data Exchange (ETDEWEB)
Robert J. Goldston
2011-04-28
Integrated energy, environment and economics modeling suggests that worldwide electrical energy use will increase from 2.4 TWe today to ~12 TWe in 2100. It will be challenging to provide 40% of this electrical power from combustion with carbon sequestration, as it will be challenging to provide 30% from renewable energy sources derived from natural energy flows. Thus nuclear power may be needed to provide ~30%, 3600 GWe, by 2100. Calculations of the associated stocks and flows of uranium, plutonium and minor actinides indicate that the proliferation risks at mid-century, using current light-water reactor technology, are daunting. There are institutional arrangements that may be able to provide an acceptable level of risk mitigation, but they will be difficult to implement. If a transition is begun to fast-spectrum reactors at mid-century, without a dramatic change in the proliferation risks of such systems, at the end of the century global nuclear proliferation risks are much greater, and more resistant to mitigation. Fusion energy, if successfully demonstrated to be economically competitive, would provide a source of nuclear power with much lower proliferation risks than fission.
Energy Technology Data Exchange (ETDEWEB)
Vega, H.J. de [Sorbonne Universites, Universite Pierre et Marie Curie UPMC Paris VI, LPTHE CNRS UMR 7589, Paris Cedex 05 (France); Sanchez, N.G. [Observatoire de Paris PSL Research University, Sorbonne Universites UPMC Paris VI, Observatoire de Paris, LERMA CNRS UMR 8112, Paris (France)
2017-02-15
The Thomas-Fermi approach to galaxy structure determines self-consistently and non-linearly the gravitational potential of the fermionic warm dark matter (WDM) particles given their quantum distribution function f(E). This semiclassical framework accounts for the quantum nature and high number of DM particles, properly describing gravitational bounded and quantum macroscopic systems as neutron stars, white dwarfs and WDM galaxies. We express the main galaxy magnitudes as the halo radius r{sub h}, mass M{sub h}, velocity dispersion and phase space density in terms of the surface density which is important to confront to observations. From these expressions we derive the general equation of state for galaxies, i.e., the relation between pressure and density, and provide its analytic expression. Two regimes clearly show up: (1) Large diluted galaxies for M{sub h} >or similar 2.3 x 10{sup 6} M {sub CircleDot} and effective temperatures T{sub 0} > 0.017 K described by the classical self-gravitating WDM Boltzman gas with a space-dependent perfect gas equation of state, and (2) Compact dwarf galaxies for 1.6 x 10{sup 6} M {sub CircleDot} >or similar M{sub h} >or similar M{sub h,min} ≅ 3.10 x 10{sup 4} (2 keV/m){sup (16)/(5)} M {sub CircleDot}, T{sub 0} < 0.011 K described by the quantum fermionic WDM regime with a steeper equation of state close to the degenerate state. In particular, the T{sub 0} = 0 degenerate or extreme quantum limit yields the most compact and smallest galaxy. In the diluted regime, the halo radius r{sub h}, the squared velocity v{sup 2}(r{sub h}) and the temperature T{sub 0} turn to exhibit square-root of M{sub h} scaling laws. The normalized density profiles ρ(r)/ρ(0) and the normalized velocity profiles v{sup 2}(r)/v{sup 2}(0) are universal functions of r/r{sub h} reflecting the WDM perfect gas behavior in this regime. These theoretical results contrasted to robust and independent sets of galaxy data remarkably reproduce the observations. For
Symmetric and asymmetric nuclear matter in the relativistic approach
International Nuclear Information System (INIS)
Huber, H.; Weber, F.; Weigel, M.K.
1995-01-01
Symmetric and asymmetric nuclear matter is studied in the framework of the relativistic Brueckner-Hartree-Fock and in the relativistic version of the so-called Λ 00 approximation. The equations are solved self-consistently in the full Dirac space, so avoiding the ambiguities in the choice of the effective scattering amplitude in matter. The calculations were performed for some modern meson-exchange potentials constructed by Brockmann and Machleidt. In some cases we used also the Groningen potentials. First, we examine the outcome for symmetric matter with respect to other calculations, which restrict themselves to positive-energy states only. The main part is devoted to the properties of asymmetric matter. In this case we obtain additionally to the good agreement with the parameters of symmetric matter, also a quite satisfactory agreement with the semiempirical macroscopic coefficients of asymmetric matter. Furthermore, we tested the assumption of a quadratic dependence of the asymmetry energy for a large range of asymmetries. Included is also the dependence of nucleon self-energies on density and neutron excess. For the purpose of comparison we discuss further the similarities and differences with relativistic Hartree and Hartree-Fock calculations and nonrelativistic Skyrme calculations
Dai, Jiayu; Hou, Yong; Yuan, Jianmin
2010-06-18
Electron-ion interactions are central to numerous phenomena in the warm dense matter (WDM) regime and at higher temperature. The electron-ion collisions induced friction at high temperature is introduced in the procedure of ab initio molecular dynamics using the Langevin equation based on density functional theory. In this framework, as a test for Fe and H up to 1000 eV, the equation of state and the transition of electronic structures of the materials with very wide density and temperature can be described, which covers a full range of WDM up to high energy density physics. A unified first principles description from condensed matter to ideal ionized gas plasma is constructed.
Pure Neutron Matter Constraints and Nuclear Symmetry Energy
International Nuclear Information System (INIS)
Fattoyev, F J; Newton, W G; Xu, Jun; Li, Bao-An
2013-01-01
In this review, we will discuss the results of our recent work [1] to study the general optimization of the pure isovector parameters of the popular relativistic mean-field (RMF) and Skyrme-Hartree-Fock (SHF) nuclear energy-density functionals (EDFs), using constraints on the pure neutron matter (PNM) equation of state (EoS) from recent ab initio calculations. By using RMF and SHF parameterizations that give equivalent predictions for ground-state properties of doubly magic nuclei and properties of symmetric nuclear matter (SNM) and PNM, we found that such optimization leads to broadly consistent symmetry energy J and its slope parameter L at saturation density within a tight range of α(J) sym , (b) the symmetry energy at supra-saturation densities, and (c) the radius of neutron stars.
Relativistic nuclear matter with alternative derivative coupling models
International Nuclear Information System (INIS)
Delfino, A.; Coelho, C.T.; Malheiro, M.
1994-01-01
Effective Lagrangians involving nucleons coupled to scalar and vector fields are investigated within the framework of relativistic mean-field theory. The study presents the traditional Walecka model and different kinds of scalar derivative coupling suggested by Zimanyi and Moszkowski. The incompressibility (presented in an analytical form), scalar potential, and vector potential at the saturation point of nuclear matter are compared for these models. The real optical potential for the models are calculated and one of the models fits well the experimental curve from-50 to 400 MeV while also gives a soft equation of state. By varying the coupling constants and keeping the saturation point of nuclear matter approximately fixed, only the Walecka model presents a first order phase transition of finite temperature at zero density. (author)
Determination of nuclear-matter temperature and density
International Nuclear Information System (INIS)
Wolf, K.L.
1980-01-01
Some of the things learned about nuclear matter under extreme conditions during the past few years in relativistic heavy ion studies are reviewed. Two developments are discussed. The completion of analyses and publication of results from the impact parameter selected, single-particle inclusive experiments have proven to be important. Preliminary results from the new generation of two-particle correlation and particle-exclusive measurements, especially those using streamer chambers, look even more definitive. Also the measurement of more exotic ejectiles with long mean free paths in nuclear matter promises to provide more basic information. Calculations are offering real guidance and are providing explanations of high energy collisions. The Monte Carlo and intranuclear cascade calculations discussed are especially informative
Strangeness in nuclear matter at DAΦNE
International Nuclear Information System (INIS)
Gianotti, P.
1998-01-01
The low energy kaons from the φ meson produced at DAΦNE offer a unique opportunity to study strangeness in nuclear matter. The interaction of kaons with hadronic matter can be investigated at DAΦNE using three main approaches: study of hypernuclei production and decay, kaons scattering on nucleons, kaonic atoms formation. These studies explore kaon-nucleon and hyperon-nucleon forces at very low energy, the nuclear shell model in presence of strangeness quantum number and eventual quarks deconfinement phenomena. The experiments devoted to study this physical program at DAΦNE are FINUDA and DEAR. The physics topics of both experiments are illustrated together with a detailed descriptions of the two detectors
Role of nuclear energy to a future society of shortage of energy resources and global warming
Energy Technology Data Exchange (ETDEWEB)
Saito, Shinzo, E-mail: saito.shinzo@jaea.go.j [Japan Atomic Energy Research Institute (Japan)
2010-03-15
Human society entered into the society of large energy consumption since the industrial revolution and consumes more than 10 billion tons of oil equivalent energy a year in the world in the present time, in which over 80% is provided by fossil fuels such as coal, oil and natural gas. Total energy consumption is foreseen to increase year by year from now on due to significant economical and population growth in the developing countries such as China and India. However, fossil fuel resources are limited with conventional crude oil estimated to last about 40 years, and it is said that the peak oil production time has come now. On the other hand, global warming due to green house gases (GHG) emissions, especially carbon dioxide, has become a serious issue. Nuclear energy plays an important role as means to resolve energy security and global warming issues. Four hundred twenty-nine nuclear power plants are operating world widely producing 16% of the total electric power with total plant capacity of 386 GWe without emission of CO{sub 2} as of 2006. It is estimated that another 250 GWe nuclear power is needed to keep the same level contribution of electricity generation in 2030. On the other hand, the Japan Atomic Energy Research Institute (JAERI) developed the very high temperature gas-cooled reactor (HTGR) named high temperature gas-cooled engineering test reactor (HTTR) and carbon free hydrogen production process (IS process). Nuclear energy utilization will surely widen in, not only electricity generation, but also various industries such as steel making, chemical industries, together with hydrogen production for transportation by introduction of HTGRs. The details of development of the HTTR and IS process are also described.
Investigation of the organic matter in inactive nuclear tank liquids
International Nuclear Information System (INIS)
Schenley, R.L.; Griest, W.H.
1990-08-01
Environmental Protection Agency (EPA) methodology for regulatory organics fails to account for the organic matter that is suggested by total organic carbon (TOC) analysis in the Oak Ridge National Laboratory (ORNL) inactive nuclear waste-tank liquids and sludges. Identification and measurement of the total organics are needed to select appropriate waste treatment technologies. An initial investigation was made of the nature of the organics in several waste-tank liquids. This report details the analysis of ORNL wastes
Self-Energy of Decuplet Baryons in Nuclear Matter
Ouellette, Stephen M.; Seki, Ryoichi
1997-01-01
We calculate, in chiral perturbation theory, the change in the self-energy of decuplet baryons in nuclear matter. These self-energy shifts are relevant in studies of meson-nucleus scattering and of neutron stars. Our results are leading order in an expansion in powers of the ratio of characteristic momenta to the chiral symmetry-breaking scale (or the nucleon mass). Included are contact diagrams generated by 4-baryon operators, which were neglected in earlier studies for the $\\Delta$ isomulti...
Mass shift of σ-meson in nuclear matter
Indian Academy of Sciences (India)
Mass shift of σ-meson in nuclear matter. J R MORONES-IBARRA1, MÓNICA MENCHACA MACIEL1,∗. ,. AYAX SANTOS-GUEVARA2 and FELIPE ROBLEDO PADILLA1. 1Facultad de Ciencias Físico-Matemáticas, Universidad Autónoma de Nuevo León, UANL,. Av. Universidad S/N Ciudad Universitaria, San Nicolás de los ...
Properties of the ρ meson in dense nuclear matter
International Nuclear Information System (INIS)
Herrmann, M.
1992-05-01
In order to reach a description of the ρ meson, which is in accordance with the principles of the gauge invariance of the electromagnetic interaction, the vector-dominance hypothesis, and the unitarity a model for the ρ meson in the vacuum is developed. Thereafter follows the calculation of the properties of the ρ meson in nuclear matter. First the connection between the spectral function of the ρ meson and the dilepton production rate for an equilibrium state is derived. Then the model for the pion in nuclear matter is described. Following approximations are applied: The description of the pion-baryon interaction pursues non-relativistically and both the width of the delta resonance and the short-range repulsive delta-nucleon interaction is neglected. The self-energy of the ρ meson in nuclear matter following from this description is formally derived from the requirement to couple the ρ meson to a conserved current. The corrections for the 3-point and 4-point vertex resulting from this are calculated and discussed. Thereafter the physical consequences of the changed self-energy of the ρ meson in nuclear matter are considered. By means of the spectral function it is shown that up to the two-fold of the ground-state density the position of the resonance is nearly not changed. At still higher densities the resonances is a little shifted to higher energies. In the range of an invariant mass of about 400 meV a strong increasement concentrated on a small range results. This is caused by coupling to a naked delta-hole state and a pion. Finally the possibilities are discussed to apply the results of this thesis to the prediction of experimental data. Thereby it is proved to be necessary to base on a simulation of the heavy ion reaction. (orig./HSI) [de
Conversion width of Σ-hyperon in nuclear matter
International Nuclear Information System (INIS)
Filimonov, V.A.
1983-01-01
Width G of ΣN→ΛN conversion for Σ - hyperon in nuclear matter on the base of one-boson exchange model is calculated. Essential compensation of contributions of diffe-- rent mesons to amplitude of the conversiop is shown to take place. As a result G decreases approximately twice as compaped with the value from exchange only by π-meson. Without accout of Pauli principle it is obtained G=15-25 MeV
Comments on nucleon mean free paths in nuclear matter
International Nuclear Information System (INIS)
Blann, M.
1977-01-01
It is suggested that recent evidence cited for a fourfold increase in the mean free path of nucleons in nuclear matter results from an error in formulation of the exciton model. The literature cited as being in support of the longer mean free path is reviewed and found to be in disagreement with the new value, and in quite reasonable agreement with results used over the past 30 years. (Auth.)
Quark mean field theory and consistency with nuclear matter
International Nuclear Information System (INIS)
Dey, J.; Tomio, L.; Dey, M.; Frederico, T.
1989-01-01
1/N c expansion in QCD (with N c the number of colours) suggests using a potential from meson sector (e.g. Richardson) for baryons. For light quarks a σ field has to be introduced to ensure chiral symmetry breaking ( χ SB). It is found that nuclear matter properties can be used to pin down the χ SB-modelling. All masses, M Ν , m σ , m ω are found to scale with density. The equations are solved self consistently. (author)
Time characteristics for the spinodal decomposition in nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Idier, D.; Farine, M.; Benhassine, B.; Remaud, B.; Sebille, F.
1992-12-31
Dynamics of the fluctuation growth are studied. Time characteristics are key quantities to determine the conditions under which spinodal decomposition could be observed. Dynamical instabilities arising from fluctuations in spinodal zone for nuclear matter are studied using Skyrme type interactions within a pseudo-particle model. Typical times for cluster formation are extracted. The numerical treatment is based on the Vlasov phase space transport equation. (K.A.) 11 refs.; 7 figs.
Time characteristics for the spinodal decomposition in nuclear matter
International Nuclear Information System (INIS)
Idier, D.; Farine, M.; Benhassine, B.; Remaud, B.; Sebille, F.
1992-01-01
Dynamics of the fluctuation growth are studied. Time characteristics are key quantities to determine the conditions under which spinodal decomposition could be observed. Dynamical instabilities arising from fluctuations in spinodal zone for nuclear matter are studied using Skyrme type interactions within a pseudo-particle model. Typical times for cluster formation are extracted. The numerical treatment is based on the Vlasov phase space transport equation. (K.A.) 11 refs.; 7 figs
Directory of Open Access Journals (Sweden)
Rui Wang
2017-10-01
Full Text Available We establish a relation between the equation of state of nuclear matter and the fourth-order symmetry energy asym,4(A of finite nuclei in a semi-empirical nuclear mass formula by self-consistently considering the bulk, surface and Coulomb contributions to the nuclear mass. Such a relation allows us to extract information on nuclear matter fourth-order symmetry energy Esym,4(ρ0 at normal nuclear density ρ0 from analyzing nuclear mass data. Based on the recent precise extraction of asym,4(A via the double difference of the “experimental” symmetry energy extracted from nuclear masses, for the first time, we estimate a value of Esym,4(ρ0=20.0±4.6 MeV. Such a value of Esym,4(ρ0 is significantly larger than the predictions from mean-field models and thus suggests the importance of considering the effects of beyond the mean-field approximation in nuclear matter calculations.
Properties of nuclear matter from macroscopic–microscopic mass formulas
Directory of Open Access Journals (Sweden)
Ning Wang
2015-12-01
Full Text Available Based on the standard Skyrme energy density functionals together with the extended Thomas–Fermi approach, the properties of symmetric and asymmetric nuclear matter represented in two macroscopic–microscopic mass formulas: Lublin–Strasbourg nuclear drop energy (LSD formula and Weizsäcker–Skyrme (WS* formula, are extracted through matching the energy per particle of finite nuclei. For LSD and WS*, the obtained incompressibility coefficients of symmetric nuclear matter are K∞=230±11 MeV and 235±11 MeV, respectively. The slope parameter of symmetry energy at saturation density is L=41.6±7.6 MeV for LSD and 51.5±9.6 MeV for WS*, respectively, which is compatible with the liquid-drop analysis of Lattimer and Lim [4]. The density dependence of the mean-field isoscalar and isovector effective mass, and the neutron–proton effective masses splitting for neutron matter are simultaneously investigated. The results are generally consistent with those from the Skyrme Hartree–Fock–Bogoliubov calculations and nucleon optical potentials, and the standard deviations are large and increase rapidly with density. A better constraint for the effective mass is helpful to reduce uncertainties of the depth of the mean-field potential.
Infinite nuclear matter based for mass of atomic nuclei
International Nuclear Information System (INIS)
Satpathy, L.
1987-01-01
The ground-state energy of an atomic nucleus with asymmetry β is considered to be equivalent to the energy of a perfect sphere made up of infinite nuclear matter of the same asymmetry plus a residual energy eta, called the local energy. Eta represents the energy due to shell, deformation, diffuseness and exchange Coulomb effects, etc. Using this picture and the generalised Hugenholtz-Van Hove theorem of many-body theory, the previously proposed mass relation is derived in a transport way in which eta drops away in a very natural manner. The validity of this mass relation is studied globally using the latest mass table. The model is suitable for the extraction of the saturation properties of nuclear matter. The binding energy per nucleon and the saturation Fermi momentum of nuclear matter obtained through this model are 18.33 MeV and 1.48 fm -1 respectively. It is shown in several representative cases in the Periodic Table that the masses of nuclei in the far unknown region can be reliably predicted. (author)
Skyrme interaction to second order in nuclear matter
Kaiser, N.
2015-09-01
Based on the phenomenological Skyrme interaction various density-dependent nuclear matter quantities are calculated up to second order in many-body perturbation theory. The spin-orbit term as well as two tensor terms contribute at second order to the energy per particle. The simultaneous calculation of the isotropic Fermi-liquid parameters provides a rigorous check through the validity of the Landau relations. It is found that published results for these second order contributions are incorrect in most cases. In particular, interference terms between s-wave and p-wave components of the interaction can contribute only to (isospin or spin) asymmetry energies. Even with nine adjustable parameters, one does not obtain a good description of the empirical nuclear matter saturation curve in the low density region 0\\lt ρ \\lt 2{ρ }0. The reason for this feature is the too strong density-dependence {ρ }8/3 of several second-order contributions. The inclusion of the density-dependent term \\frac{1}{6}{t}3{ρ }1/6 is therefore indispensable for a realistic description of nuclear matter in the Skyrme framework.
Infinite nuclear matter model and mass formulae for nuclei
International Nuclear Information System (INIS)
Satpathy, L.
2016-01-01
The matter composed of the nucleus is a quantum-mechanical interacting many-fermionic system. However, the shell and classical liquid drop have been taken as the two main features of nuclear dynamics, which have guided the evolution of nuclear physics. These two features can be considered as the macroscopic manifestation of the microscopic dynamics of the nucleons at fundamental level. Various mass formulae have been developed based on either of these features over the years, resulting in many ambiguities and uncertainties posing many challenges in this field. Keeping this in view, Infinite Nuclear Matter (INM) model has been developed during last couple of decades with a many-body theoretical foundation employing the celebrated Hugenholtz-Van Hove theorem, quite appropriate for the interacting quantum-mechanical nuclear system. A mass formula called INM mass formula based on this model yields rms deviation of 342 keV being the lowest in literature. Some of the highlights of its result includes its determination of INM density in agreement with the electron scattering data leading to the resolution of the long standing 'r 0 -paradox' it predicts new magic numbers giving rise to new island of stability in the drip-line regions. This is the manifestation of a new phenomenon where shell-effect over comes the repulsive component of nucleon-nucleon force resulting in the broadening of the stability peninsula. Shell quenching in N= 82,and N= 126 shells, and several islands of inversion have been predicted. The model determines the empirical value of the nuclear compression modulus, using high precission 4500 data comprising nuclear masses, neutron and proton separation energies. The talk will give a critical review of the field of mass formula and our understanding of nuclear dynamics as a whole
Finite size effects in neutron star and nuclear matter simulations
Energy Technology Data Exchange (ETDEWEB)
Giménez Molinelli, P.A., E-mail: pagm@df.uba.ar; Dorso, C.O.
2015-01-15
In this work we study molecular dynamics simulations of symmetric nuclear and neutron star matter using a semi-classical nucleon interaction model. Our aim is to gain insight on the nature of the so-called “finite size effects”, unavoidable in this kind of simulations, and to understand what they actually affect. To do so, we explore different geometries for the periodic boundary conditions imposed on the simulation cell: cube, hexagonal prism and truncated octahedron. For nuclear matter simulations we show that, at sub-saturation densities and low temperatures, the solutions are non-homogeneous structures reminiscent of the “nuclear pasta” phases expected in neutron star matter simulations, but only one structure per cell and shaped by specific artificial aspects of the simulations—for the same physical conditions (i.e. number density and temperature) different cells yield different solutions. The particular shape of the solution at low enough temperature and a given density can be predicted analytically by surface minimization. We also show that even if this behavior is due to the imposition of periodic boundary conditions on finite systems, this does not mean that it vanishes for very large systems, and it is actually independent of the system size. We conclude that, for nuclear matter simulations, the cells' size sets the only characteristic length scale for the inhomogeneities, and the geometry of the periodic cell determines the shape of those inhomogeneities. To model neutron star matter we add a screened Coulomb interaction between protons, and perform simulations in the three cell geometries. Our simulations indeed produce the well known nuclear pasta, with (in most cases) several structures per cell. However, we find that for systems not too large results are affected by finite size in different ways depending on the geometry of the cell. In particular, at the same certain physical conditions and system size, the hexagonal prism yields a
Covariant description of dynamical processes in relativistic nuclear matter
International Nuclear Information System (INIS)
Celenza, L.S.; Pantziris, A.; Shakin, C.M.
1992-01-01
We report results of covariant calculations of density-dependent polarization processes in relativistic nuclear matter. We consider the polarization induced by those mesons that play an important role in the boson-exchange model of nuclear forces (σ,π,ρ,ω). After obtaining the polarization operators, we construct the propagators for these mesons. The covariant nature of the calculation greatly clarifies the structure of the polarization operators and associated Green's functions. (In addition to the meson momentum, these quantities depend upon another four-vector, η μ , that describes the uniform motion of the medium.) In the case of the pion, we show that the same results are obtained for pseudovector or pseudoscalar coupling to the nucleon, if the associated Lagrangians are related by chiral transformations. Of particular interest are the extremely large values found for the polarization operators of the omega and sigma mesons. It is also found that the coupling of the sigma and omega fields through the polarization process is also extremely large. (Because of these results one cannot usefully consider the sigma and omega fields as independent degrees of freedom in nuclear matter.) We describe methods for reorganizing the calculation of ring diagrams in which we group those diagrams that exhibit strong cancellations. We also comment on the implication of our results for nuclear structure studies
Towards a chiral effective field theory of nuclear matter
International Nuclear Information System (INIS)
Mallik, S.
2008-01-01
As a preliminary attempt to formulate an effective theory of nuclear matter, we undertake to calculate the effective pole parameters of nucleon in such a medium. We begin with the virial expansion of these parameters to leading order in nucleon number density in terms of the on-shell NN scattering amplitude. We then proceed to calculate the same parameters in the effective theory, getting a formula for the nucleon mass-shift to leading order, that was known already to give too large a value to be acceptable at normal nuclear density. At this point the virial expansion suggests a modification of this formula, which we carry out following Weinberg's method for the two-nucleon system in the effective theory. The results are encouraging enough to attempt a complete, next-to-leading order calculation of the off-shell nucleon spectral function in nuclear medium. (author)
The effective action approach applied to nuclear matter (1)
International Nuclear Information System (INIS)
Tran Huu Phat; Nguyen Tuan Anh.
1996-11-01
Within the framework of the Walecka model (QHD-I) the application of the Cornwall-Jackiw-Tomboulis (CJT) effective action to nuclear matter is presented. The main feature is the treating of the meson condensates for the system of finite nuclear density. The system of couple Schwinger-Dyson (SD) equations is derived. It is shown that SD equations for sigma-omega mixings are absent in this formalism. Instead, the energy density of the nuclear ground state does explicitly contain the contributions from the ring diagrams, amongst others. In the bare-vertex approximation, the expression for energy density is written down for numerical computation in the next paper. (author). 14 refs, 3 figs
Thermodynamic instabilities in hot and dense nuclear matter
Directory of Open Access Journals (Sweden)
Lavagno A.
2016-01-01
Full Text Available We study the presence of thermodynamic instabilities in a hot and dense nuclear medium where a nuclear phase transition can take place. Similarly to the low density nuclear liquid-gas phase transition, we show that such a phase transition is characterized by pure hadronic matter with both mechanical instability (fluctuations on the baryon density that by chemical-diffusive instability (fluctuations on the strangeness concentration. The analysis is performed by requiring the global conservation of baryon number and zero net strangeness in the framework of an effective relativistic mean field theory with the inclusion of the Δ(1232-isobars, hyperons and the lightest pseudoscalar and vector meson degrees of freedom. It turns out that in this situation hadronic phases with different values of strangeness content may coexist, altering significantly meson-antimeson ratios.
Properties of rho and eta mesons in nuclear matter
International Nuclear Information System (INIS)
Herrmann, M.; Sauermann, C.; Friman, B.L.; Technische Hochschule Darmstadt; Noerenberg, W.; Technische Hochschule Darmstadt
1993-10-01
The properties of ρ- and η-mesons in nuclear matter are studied within the scope of hadronic models. Unknown model parameters are obtained from fits to scattering data. - The treatment of the ρ-meson includes the coupling to two pions which, in matter, are strongly mixed with delta-particle-nucleon-hole states. The ρ-meson self-energy is evaluated in a current conserving approximation with in-medium pion propagators and vertex corrections. While the position of the original peak in the spectral function remains almost unchanged, its width grows rapidly with increasing density. Consequently, the ρ-meson strength function is strongly dispersed at high densities. Due to vertex corrections a new peak at a mass around 3m π emerges with increasing density, while the spectral function around the two-pion threshold is found to be smooth at all densities. The η-meson is strongly mixed with N * (1535)-particle-nucleon-hole states in nuclear matter. The corresponding dispersion relations with an upper and a lower branch look similar to those of the (π, ΔN -1 )-modes. However, since the N * is an S-wave resonance in the ηN-channel, the repulsion of the two branches survives at zero momentum. (orig.)
The effect of thermal velocities on structure formation in N-body simulations of warm dark matter
Leo, Matteo; Baugh, Carlton M.; Li, Baojiu; Pascoli, Silvia
2017-11-01
We investigate the impact of thermal velocities in N-body simulations of structure formation in warm dark matter models. Adopting the commonly used approach of adding thermal velocities, randomly selected from a Fermi-Dirac distribution, to the gravitationally-induced velocities of the simulation particles, we compare the matter and velocity power spectra measured from CDM and WDM simulations, in the latter case with and without thermal velocities. This prescription for adding thermal velocities introduces numerical noise into the initial conditions, which influences structure formation. At early times, the noise affects dramatically the power spectra measured from simulations with thermal velocities, with deviations of the order of ~ Script O(10) (in the matter power spectra) and of the order of ~ Script O(102) (in the velocity power spectra) compared to those extracted from simulations without thermal velocities. At late times, these effects are less pronounced with deviations of less than a few percent. Increasing the resolution of the N-body simulation shifts these discrepancies to higher wavenumbers. We also find that spurious haloes start to appear in simulations which include thermal velocities at a mass that is ~3 times larger than in simulations without thermal velocities.
Bombaci, Ignazio; Logoteta, Domenico
2018-02-01
Aims: We report a new microscopic equation of state (EOS) of dense symmetric nuclear matter, pure neutron matter, and asymmetric and β-stable nuclear matter at zero temperature using recent realistic two-body and three-body nuclear interactions derived in the framework of chiral perturbation theory (ChPT) and including the Δ(1232) isobar intermediate state. This EOS is provided in tabular form and in parametrized form ready for use in numerical general relativity simulations of binary neutron star merging. Here we use our new EOS for β-stable nuclear matter to compute various structural properties of non-rotating neutron stars. Methods: The EOS is derived using the Brueckner-Bethe-Goldstone quantum many-body theory in the Brueckner-Hartree-Fock approximation. Neutron star properties are next computed solving numerically the Tolman-Oppenheimer-Volkov structure equations. Results: Our EOS models are able to reproduce the empirical saturation point of symmetric nuclear matter, the symmetry energy Esym, and its slope parameter L at the empirical saturation density n0. In addition, our EOS models are compatible with experimental data from collisions between heavy nuclei at energies ranging from a few tens of MeV up to several hundreds of MeV per nucleon. These experiments provide a selective test for constraining the nuclear EOS up to 4n0. Our EOS models are consistent with present measured neutron star masses and particularly with the mass M = 2.01 ± 0.04 M⊙ of the neutron stars in PSR J0348+0432.
Rare isotopes and the sound of dilute nuclear matter
Papakonstantinou, P.
2018-04-01
Dilute baryonic matter, at densities below the normal saturation density of symmetric matter, is found on the crust of neutron stars and in collapsing supernova matter, its properties determining the evolution of those stellar objects. It is also readily found on the surface of ordinary and exotic atomic nuclei and lives fleetingly in the form of space-extended resonances of excited nucleons. Liminal states of nuclear matter, between saturation and full evaporation or clusterization, are manifest in the structure of symmetric nuclei through clustering and of very asymmetric rare species in haloes and the neutron skin; they stand literally at the threshold of a nucleus's response to hadronic probes, including processes which hinder or enable fusion. In this contribution I focus on excited states, and in particular exotic or not-so-exotic dipole excitation modes of N = Z nuclei and neutron-rich species, including new theoretical results on threshold strength. Modes of special interest are vibrations of and within diffuse surface layers and alpha-cluster oscillations. The modeling of such processes is relevant, directly or indirectly, for the description of reactions at astrophysical energies.
Nucleon-nucleon correlations in dense nuclear matter
International Nuclear Information System (INIS)
Alm, T.
1993-02-01
In this thesis new results on the problematics of the formation of nucleon-nucleon correlations in nuclear matter could be presented. Starting from a general study of the two-particle problem in matter we studied the occurrence of a suprafluid phase (pair condensate of nucleons). The Gorkov decoupling by means of anomalous Green functions was generalized, so that also Cooper pairs with spin 1 (triplet pairing) can be described. A generalized gap equation resulted, which permits to determine the order parameters of the suprafluied phase in arbitrary channels of the nucleon-nucleon scattering states. This equation was solvd in the 1 S 0 -, in the 3 P 2 - 3 F 2 , and in the 3 S 1 - 3 D 1 channel under application of realistic nucleon-nucleon potentials. The behaviour of the resulting gap parameters in the single channels was studied as function of density and temperature. (orig.) [de
Energy Technology Data Exchange (ETDEWEB)
Muller, Richard A.
2011-04-26
This book explains the science behind the concerns that our nation faces in the immediate future. It outlines the tools of terrorists, the dangers of nuclear power, and the reality of global warming. As citizens who will elect future presidents of the most powerful and influential countries in the world, we need to know-truly understand if Iran's nascent nuclear capability is a genuine threat to the West, if biochemical weapons are likely to be developed by terrorists, if there are viable alternatives to fossil fuels that should be nurtured and supported by the government, if nuclear power should be encouraged, and if global warming is actually happening. This book is written in everyday, nontechnical language on the science behind the concerns that our nations faces in the immediate future. This book is translated from 'Physics for Future Presidents: The Science Behind the Headlines', published by W. W. Norton and Company in August 2008. Contents: 1 - Terrorism: Nine-eleven, Terrorist nukes, The next terrorist attack, Biological terrorism; 2 - Energy: Key energy surprises, Solar Power, The end of oil; 3 - Nukes: Radioactivity and death, Radioactive decay, Nuclear weapons, Nuclear madness, Nuclear power, Nuclear waste, Controlled fusion; 4 - Space: Space and satellites, Gravity applications, Humans in space, Spying with invisible light; 5 - Global Warming: A brief history of climate, The greenhouse effect, A very likely cause, Evidence, Non-solutions, The fruit on the ground, New technologies
International Nuclear Information System (INIS)
Ishino, Masahiko; Hasegawa, Noboru; Nishikino, Masaharu; Kawachi, Tetsuya; Yamagiwa, Mitsuru; Pikuz, Tatiana; Skobelev, Igor; Faenov, Anatoly; Inogamov, Nail
2014-01-01
We investigated the optical emission from the ablating surfaces induced by the irradiations of soft x-ray laser (SXRL) pulses with the aim of estimation of the maximum electron temperature. No emission signal in the spectral range of 400–800 nm could be observed despite the formation of damage structures on the target surfaces. Hence, we estimated an upper limit for the electron temperature of 0.4–0.7 eV for the process duration of 100–1000 ps. Our results imply that the ablation and/or surface modification by the SXRL is not accompanied by plasma formation but is induced by thermo-mechanical pressure, which is so called a spallative ablation. This spallative ablation process occurs in the low electron temperature region of a non-equilibrium state of warm dense matter
Equidistant structure and effective nucleon mass in nuclear matter
International Nuclear Information System (INIS)
Tezuka, Hirokazu.
1981-11-01
The effective nucleon mass of the Equidistant Multi-Layer Structure (EMULS) is discussed self-consistently. In the density region where the Fermi gas state in nuclear matter is unstable against the density fluctuation, the EMULS gives lower binding energy. It is, however, shown that such a structure with an ordinary nucleon mass collapses due to too strong attraction. We point out that such a collapse can be avoided by taking account of an effective nucleon mass affected by the localization of nucleons. (author)
Thermostatic properties of semi-infinite polarized nuclear matter
International Nuclear Information System (INIS)
Abd-Alla, M.; Hassan, M.Y.M.; Ramadan, S.
1988-03-01
The surface and curvature properties of semi-infinite polarized nuclear matter (SPNM) are calculated using an expansion for the Fermi integrals up to T 2 . A density matrix expansion is obtained for a modified form of Seyler-Blanchard interaction. New parameters that characterize the surface and curvature properties of SPNM are introduced. The level density parameter is extracted from the low temperature expansion of the free energy and compared with previous calculations. A reasonable agreement is obtained for the parameters calculated before. (author). 78 refs, 1 fig., 5 tabs
Quark mean field theory and consistency with nuclear matter
International Nuclear Information System (INIS)
Dey, J.; Dey, M.; Frederico, T.; Tomio, L.
1990-09-01
1/N c expansion in QCD (with N c the number of colours) suggests using a potential from meson sector (e.g. Richardson) for baryons. For light quarks a σ field has to be introduced to ensure chiral symmetry breaking ( χ SB). It is found that nuclear matter properties can be used to pin down the χ SB-modelling. All masses, M N , m σ , m ω are found to scale with density. The equations are solved self consistently. (author). 29 refs, 2 tabs
Onset of superfluidity in hot asymmetric nuclear matter
International Nuclear Information System (INIS)
Alm, T.; Roepke, G.; Friman, B.L.
1991-05-01
The onset of superfluidity in hot asymmetric nuclear matter is studied within a generalized Beth-Uhlenbeck approach. The finite tempeature t-matrix is of the Bethe-Goldstone type and contains hole-hole propagation not considered in the Brueckner G-matrix approach. It is shown that the phase contour for the onset of superfluidity in this approach is identical to that obtained within Gorkov's approach to BCS theory. Results for the realistic Paris potential imply that the critical temperature in the neutron-proton triplet channel is on the order of 6-8 MeV and thus much larger than that for singlet pairing. (orig.)
Mass shift of σ-meson in nuclear matter
International Nuclear Information System (INIS)
Morones-Ibarra, J.R.; Maciel, Mónica Menchaca; Padilla, Felipe Robledo; Santos-Guevara, Ayax
2013-01-01
The propagation of σ-meson in nuclear matter is studied in the Walecka model, by assuming that sigma couples to a pair of nucleon-antinucleon states to particle-hole states. The in-medium effect of σ-ω mixing is also studied. For completeness, the coupling of sigma to two virtual pions was also considered. It is found that the σ-meson mass decreases with respect to its value in vacuum and that the contribution of the σ-ω mixing effect on the mass shift is relatively small. (author)
No pion condensate in nuclear matter due to fluctuations
International Nuclear Information System (INIS)
Kleinert, H.
1981-01-01
We show that if pion condensation occurs in a mean-field theory of infinite nuclear matter, fluctuations completely prevent the formation of a condensate as well as of the associated Goldstone mode. Thus if an increase of opalescence should ever be observed experimentally, it is these fluctuations which are measured rather than the scattering on the Goldstone modes. They preserve isotopic symmetry and increase very smoothly as the density passes the formerly critical density. There are no discontinuities in any thermodynamic quantitiy. (orig.)
Self-consistent determination of quasiparticle properties in nuclear matter
International Nuclear Information System (INIS)
Oset, E.; Palanques-Mestre, A.
1981-01-01
The self-energy of nuclear matter is calculated by directing the attention to the energy and momentum dependent pieces which determine the quasiparticle properties. A microscopic approach is followed which starts from the boson exchange picture for the NN interaction, then the π-and p-mesons are shown to play a major role in the nucleon renormalization. The calculation is done self-consistently and the effective mass and pole strength determined as a function of the nuclear density and momentum. Particular emphasis is put on the non-static character of the interaction and its consequences. Finally a comparison is made with other calculations and with experimental results. The consequences of the nucleon renormalization in pion condensation are also examined with the result that the critical density is pushed up appreciably. (orig.)
Is a condensed state of nuclear matter possible?
International Nuclear Information System (INIS)
D'yakonov, D.I.; Mirlin, A.D.
1988-01-01
Nucleon chiral models naturally lead to the concept of ''generalized'' or ''classical'' nucleons which are characterized by a definite orientation in spin-isospin space. Nucleons and Δ resonances are different rotational states of generalized nucleons. Interaction of two generalized nucleons is sharply anisotropic and at a definite relative orientation leads to very strong attraction. This gives an idea of possible existence of a condensed state of nuclear matter, i.e. of a crystal or Fermi liquid with a short-range order which consists of N and Δ coherent superpositions. The variational estimate shows that at densities a few times that of the standard nuclear density this condensed state may be energetically favourable
Nuclear matter calculations with a pseudoscalar-pseudovector chiral model
Energy Technology Data Exchange (ETDEWEB)
Niembro, R.; Marcos, S.; Bernardos, P. [University of Cantabria, Faculty of Sciences, Department of Modern Physics, 39005 Santander (Spain); Fomenko, V.N. [St Petersburg University for Railway Engineering, Department of Mathematics, 197341 St Petersburg (Russian Federation); Savushkin, L.N. [St Petersburg University for Telecomunications, Department of Physics, 191065 St Petersburg (Russian Federation); Lopez-Quelle, M. [University of Cantabria, Faculty of Sciences, Department of Applied Physics, 39005 Santander, Spain (Spain)
1998-10-01
A mixed pseudoscalar-pseudovector {pi}N coupling relativistic Lagrangian is obtained from a pure pseudoscalar chiral one, by transforming the nucleon field according to a generalized Weinberg transformation, which depends on a mixing parameter. The interaction is generated by the {sigma}, {omega} and {pi} meson exchanges. Within the Hartree-Fock context, pion polarization effects, including the {delta} isobar, are considered in the random phase approximation in nuclear matter. These effects are interpreted, in a non-relativistic framework, as a modification of the range and intensity of a Yukawa-type potential by means of a simple function which takes into account the nucleon-hole and {delta}-hole excitations. Results show stability of relativistic nuclear matter against pion condensation. Compression modulus is diminished by the combined effects of the nucleon and {delta} polarization towards the usually accepted experimental values. The {pi}N interaction strength used in this paper is less than the conventional one to ensure the viability of the model. The fitting parameters of the model are the scalar meson mass m{sub {sigma}} and the {omega}-N coupling constant g{sub {omega}}. (author)
Strange quark matter in the Universe and accelerator nuclear beams
International Nuclear Information System (INIS)
Okonov, Eh.
1995-01-01
An almost symmetric mixture of u, d and s-quarks - Strange Quark Matter (SQM) is strongly argued to be the ground and absolutely stable of the matter. Astrophysical objects, supposed to be the SQM states, could be formed as the result of the Big Bang (in the early Universe) and the conversion of neutron stars into strange ones. Such objects are considered to be favourable candidates as black holes. The unique possibility to produce the SQM under terrestrial conditions (at accelerator laboratories) are violent relativistic nucleus-nucleus collisions so called 'little big bang'. The expected singulares of SQM are reviewed which could be revealed from astrophysical observations of peculiarities of large SQM objects as well as from accelerator experiments with searching smaller SQM states including the simplest one - metastable six-quark H dihyperon. The first results of the Dubna search experiments, with considerable heating of matter and formation a dense strangeness abundant fireball (mixed phase?) in central nuclear collisions, is presented. Under these favourable conditions a candidate for H dihyperon is observed and an upper limit of production cross sections of this SQM state is estimated. Some prospects and advantages of further searches for light SQM states, using the JINR new superconducting accelerator - Nuclotron with energy 5-6 GeV per nucleon, are briefly outlined. 19 refs., 7 figs
Discovery potential for directional dark matter detection with nuclear emulsions
Guler, A. M.; NEWSdm Collaboration
2017-06-01
Direct Dark Matter searches are nowadays one of the most exciting research topics. Several Experimental efforts are concentrated on the development, construction, and operation of detectors looking for the scattering of target nuclei with Weakly Interactive Massive Particles (WIMPs). In this field a new frontier can be opened by directional detectors able to reconstruct the direction of the WIMP-recoiled nucleus thus allowing to extend dark matter searches beyond the neutrino floor. Exploiting directionality would also give a proof of the galactic origin of dark matter making it possible to have a clear and unambiguous signal to background separation. The angular distribution of WIPM-scattered nuclei is indeed expected to be peaked in the direction of the motion of the Solar System in the Galaxy, i.e. toward the Cygnus constellation, while the background distribution is expected to be isotropic. Current directional experiments are based on the use of gas TPC whose sensitivity is limited by the small achievable detector mass. In this paper we show the potentiality in terms of exclusion limit of a directional experiment based on the use of a solid target made by newly developed nuclear emulsions and read-out systems reaching sub-micrometric resolution.
Boiling Patterns of Iso-asymmetric Nuclear Matter
International Nuclear Information System (INIS)
Tõke, Jan
2013-01-01
Limits of thermodynamic metastability of self-bound neutron-rich nuclear matter are explored within the framework of microcanonical thermodynamics of interacting Fermi Gas model in Thomas-Fermi approximation. It is found that as the excitation energy per nucleon of the system is increased beyond a certain limiting value, the system loses metastability and becomes unstable with respect to joint fluctuations in excitation energy per nucleon and in isospin per nucleon. As a result, part of the system is forced to boil off in a form of iso-rich non-equilibrated vapors. Left behind in such a process, identifiable with distillation, is a more iso-symmetric metastable residue at a temperature characteristic of its residual isospin content. With a progressing increase in the initial excitation energy per nucleon, more neutron-rich matter is boiled off and a more iso-symmetric residue is left behind with progressively increasing characteristic temperature. Eventually, when all excess neutrons are shed, the system boils uniformly with a further supply of excitation energy, leaving behind a smaller and smaller residue at a characteristic boiling-point temperature of iso-symmetric matter.
Antiferromagnetism of nuclear matter in the model with effective Gogny interaction
International Nuclear Information System (INIS)
Isayev, A.A.; Yang, J.
2006-01-01
The possibility of ferromagnetic (FM) antiferromagnetic (AFM) phase transitions in symmetric nuclear matter is analyzed within the framework of a Fermi-liquid theory with the effective Gogny interaction. It is shown that at some critical density nuclear matter undergoes a phase transition to the AFM spin state. The self-consistent equations of spin-polarized nuclear matter have no solutions corresponding to FM spin ordering and, hence, the FM transition does not appear. The AFM spin state properties are investigated [ru
Quark condensates in nuclear matter in the global color symmetry model of QCD
International Nuclear Information System (INIS)
Liu Yuxin; Gao Dongfeng; Guo Hua
2003-01-01
With the global color symmetry model being extended to finite chemical potential, we study the density dependence of the local and nonlocal scalar quark condensates in nuclear matter. The calculated results indicate that the quark condensates increase smoothly with the increasing of nuclear matter density before the critical value (about 12ρ 0 ) is reached. It also manifests that the chiral symmetry is restored suddenly as the density of nuclear matter reaches its critical value. Meanwhile, the nonlocal quark condensate in nuclear matter changes nonmonotonously against the space-time distance among the quarks
Greenberg, Michael; Truelove, Heather Barnes
2011-05-01
A survey of 3,200 U.S. residents focused on two issues associated with the use of nuclear and coal fuels to produce electrical energy. The first was the association between risk beliefs and preferences for coal and nuclear energy. As expected, concern about nuclear power plant accidents led to decreased support for nuclear power, and those who believed that coal causes global warming preferred less coal use. Yet other risk beliefs about the coal and nuclear energy fuel cycles were stronger or equal correlates of public preferences. The second issue is the existence of what we call acknowledged risk takers, respondents who favored increased reliance on nuclear energy, although also noting that there could be a serious nuclear plant accident, and those who favored greater coal use, despite acknowledging a link to global warming. The pro-nuclear group disproportionately was affluent educated white males, and the pro-coal group was relatively poor less educated African-American and Latino females. Yet both shared four similarities: older age, trust in management, belief that the energy facilities help the local economy, and individualistic personal values. These findings show that there is no single public with regard to energy preferences and risk beliefs. Rather, there are multiple populations with different viewpoints that surely would benefit by hearing a clear and comprehensive national energy life cycle policy from the national government. © 2010 Society for Risk Analysis.
J/psi production in proton-nucleus collisions at ALICE: cold nuclear matter really matters
CERN. Geneva
2013-01-01
Heavy quarkonia are expected to be sensitive to the properties of strongly interacting matter, at both low and high temperatures. In nucleus-nucleus collisions, a phase transition to a deconfined state of quarks and gluons (Quark-Gluon Plasma) is thought to take place once the temperature of the system exceeds a critical temperature of the order of 150-200 MeV. The deconfined state can induce a suppression of charmonium (due to color screening, dominant at SPS and RHIC energies), which can be overturned at LHC energy by the (re)combination of the large number of free c and cbar quarks, taking place when the system cools down below the critical temperature. Cold nuclear matter also has an influence on heavy quarkonia. Such effects can be studied in proton-nucleus collisions, where no deconfined state is expected to be created. At LHC energy, they mainly include nuclear shadowing, gluon saturation, break-up of the quarkonium states, and parton energy loss in the initial and final state. The study of these eff...
A Study of Nuclear Recoil Backgrounds in Dark Matter Detectors
Energy Technology Data Exchange (ETDEWEB)
Westerdale, Shawn S. [Princeton Univ., NJ (United States)
2016-01-01
Despite the great success of the Standard Model of particle physics, a preponderance of astrophysical evidence suggests that it cannot explain most of the matter in the universe. This so-called dark matter has eluded direct detection, though many theoretical extensions to the Standard Model predict the existence of particles with a mass on the $1-1000$ GeV scale that interact only via the weak nuclear force. Particles in this class are referred to as Weakly Interacting Massive Particles (WIMPs), and their high masses and low scattering cross sections make them viable dark matter candidates. The rarity of WIMP-nucleus interactions makes them challenging to detect: any background can mask the signal they produce. Background rejection is therefore a major problem in dark matter detection. Many experiments greatly reduce their backgrounds by employing techniques to reject electron recoils. However, nuclear recoil backgrounds, which produce signals similar to what we expect from WIMPs, remain problematic. There are two primary sources of such backgrounds: surface backgrounds and neutron recoils. Surface backgrounds result from radioactivity on the inner surfaces of the detector sending recoiling nuclei into the detector. These backgrounds can be removed with fiducial cuts, at some cost to the experiment's exposure. In this dissertation we briefly discuss a novel technique for rejecting these events based on signals they make in the wavelength shifter coating on the inner surfaces of some detectors. Neutron recoils result from neutrons scattering from nuclei in the detector. These backgrounds may produce a signal identical to what we expect from WIMPs and are extensively discussed here. We additionally present a new tool for calculating ($\\alpha$, n)yields in various materials. We introduce the concept of a neutron veto system designed to shield against, measure, and provide an anti-coincidence veto signal for background neutrons. We discuss the research and
A study of nuclear recoil backgrounds in dark matter detectors
Westerdale, Shawn S.
Despite the great success of the Standard Model of particle physics, a preponderance of astrophysical evidence suggests that it cannot explain most of the matter in the universe. This so-called dark matter has eluded direct detection, though many theoretical extensions to the Standard Model predict the existence of particles with a mass on the 1-1000 GeV scale that interact only via the weak nuclear force. Particles in this class are referred to as Weakly Interacting Massive Particles (WIMPs), and their high masses and low scattering cross sections make them viable dark matter candidates. The rarity of WIMP-nucleus interactions makes them challenging to detect: any background can mask the signal they produce. Background rejection is therefore a major problem in dark matter detection. Many experiments greatly reduce their backgrounds by employing techniques to reject electron recoils. However, nuclear recoil backgrounds, which produce signals similar to what we expect from WIMPs, remain problematic. There are two primary sources of such backgrounds: surface backgrounds and neutron recoils. Surface backgrounds result from radioactivity on the inner surfaces of the detector sending recoiling nuclei into the detector. These backgrounds can be removed with fiducial cuts, at some cost to the experiment's exposure. In this dissertation we briefly discuss a novel technique for rejecting these events based on signals they make in the wavelength shifter coating on the inner surfaces of some detectors. Neutron recoils result from neutrons scattering off of nuclei in the detector. These backgrounds may produce a signal identical to what we expect from WIMPs and are extensively discussed here. We additionally present a new tool for calculating (alpha, n) yields in various materials. We introduce the concept of a neutron veto system designed to shield against, measure, and provide an anti-coincidence veto signal for background neutrons. We discuss the research and development
International Nuclear Information System (INIS)
Xu Chang; Li Baoan; Chen Liewen; Ko, Che Ming
2011-01-01
Using the Hugenholtz-Van Hove theorem, we derive general expressions for the quadratic and quartic symmetry energies in terms of the isoscalar and isovector parts of single-nucleon potentials in isospin asymmetric nuclear matter. These expressions are useful for gaining deeper insights into the microscopic origins of the uncertainties in our knowledge on nuclear symmetry energies especially at supra-saturation densities. As examples, the formalism is applied to two model single-nucleon potentials that are widely used in transport model simulations of heavy-ion reactions.
Differential isospin-fractionation in dilute asymmetric nuclear matter
International Nuclear Information System (INIS)
Li Baoan; Chen Liewen; Ma Hongru; Xu Jun; Yong Gaochan
2007-01-01
The differential isospin-fractionation (IsoF) during the liquid-gas phase transition in dilute asymmetric nuclear matter is studied as a function of nucleon momentum. Within a self-consistent thermal model it is shown that the neutron/proton ratio of the gas phase becomes smaller than that of the liquid phase for energetic nucleons, although the gas phase is overall more neutron-rich. Clear indications of the differential IsoF consistent with the thermal model predictions are demonstrated within a transport model for heavy-ion reactions. Future comparisons with experimental data will allow us to extract critical information about the momentum dependence of the isovector strong interaction
Two-body correlation functions in dilute nuclear matter
International Nuclear Information System (INIS)
Isayev, A A
2006-01-01
Finding the distinct features of the crossover from the regime of large overlapping Cooper pairs to the limit of non-overlapping pairs of fermions (Shafroth pairs) in multicomponent Fermi systems remains one of the actual problems in a quantum many-body theory. Here this transition is studied by calculating the two-body density, spin and isospin correlation functions in dilute asymmetric nuclear matter. It is shown that criterion of the crossover (Phys. Rev. Lett. 95, 090402 (2005)), consisting in the change of the sign of the density correlation function at low momentum transfer, fails to describe correctly the density-driven BEC-BCS transition at finite isospin asymmetry or finite temperature. As an unambiguous signature of the BEC-BCS transition, there can be used the presence (BCS regime) or absence (BEC regime) of the singularity in the momentum distribution of the quasiparticle density of states
Study of the Λ(1116 interaction in cold nuclear matter
Directory of Open Access Journals (Sweden)
Arnold Oliver
2014-03-01
Full Text Available The interaction of Λ hyperons with baryonic nuclear matter at saturation density is expected to be attractive. The interaction strength was extracted from hypernuclei data. A different approach to obtain the potential depth of the Λ mean-field potential is to compare experimental data with transport simulations. We analyze experimental data of Λ hyperons measured with the HADES detector in p+93Nb reactions with a kinetic beam energy of 3.5 GeV carried by the proton. The high statistic of measured Λ hyperons allows us to perform a double differential analysis in Lorentz-invariant observables of transverse momentum and rapidity. We present the analysis method and a comparison with simulations.
Hyperon interaction in free space and nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Dhar, Madhumita; Lenske, Horst [Institute for Theoretical Physics, Justus- Liebig-University Giessen (Germany)
2015-07-01
Baryon-baryon interactions within the SU(3)-octet are investigated in free space and nuclear matter.A meson exchange model based on SU(3) symmetry is used for determining the interaction. The Bethe-Salpeter equations are solved in a 3-D reduction scheme. In-medium effect has been incorporated by including a two particle Pauli projector operator in the scattering equation. The coupling of the various channels of total strangeness S and conserved total charge is studied in detail. Special attention is paid to the physical thresholds. The density dependence of interaction is clearly seen in the variation of the in-medium low-energy parameters. The approach is compared to descriptions derived from chiral-EFT and other meson-exchange models e.g. the Nijmegen and the Juelich model.
Effective pion--nucleon interaction in nuclear matter
International Nuclear Information System (INIS)
Celenza, L.S.; Liu, L.C.; Nutt, W.; Shakin, C.M.
1976-01-01
We discuss the modification of the interaction between a pion and a nucleon in the presence of an infinite medium of nucleons (nuclear matter). The theory presented here is covariant and is relevant to the calculation of the pion--nucleus optical potential. The specific effects considered are the modifications of the nucleon propagator due to the Pauli principle and the modification of the pion and nucleon propagators due to collisions with nucleons of the medium. We also discuss in detail the pion self-energy in the medium, paying close attention to off-shell effects. These latter effects are particularly important because of the rapid variation with energy of the fundamental pion--nucleon interaction. Numerical results are presented, the main feature being the appearance of a significant damping width for the (3, 3) resonance
Static and Covariant Meson-Exchange Interactions in Nuclear Matter
International Nuclear Information System (INIS)
Carlson, B.V.; Hirata, D.
2011-01-01
The Dirac version of static meson exchange interactions provides a good description of low-energy NN scattering as well as very reasonable saturation properties in Dirac-Brueckner calculations of nuclear matter. We include retardation terms to make these interactions covariant and readjust the coupling constants so as to maintain a reasonable description of NN scattering. In this case, we find the Dirac-Brueckner approximation to nuclear matter to be extremely overbound. The Bonn meson-exchange interactions provide a good fit to low-energy nucleon-nucleon scattering and the deuteron binding energy using a static interaction and the Thompson form of the reduced two-nucleon interaction. We have readjusted the coupling constants of the these interactions to obtain almost equivalent fits to the scattering data and deuteron binding energy with a static interaction and the Blankenbecler-Sugar form of the reduced two-nucleon propagator and using both forms of the propagator with a covariant interaction. Dirac-Brueckner calculations using the static interactions furnish saturation properties similar to those found for the Bonn interactions. The covariant interactions, on the contrary, yield extreme overbinding and do not show signs of saturation before our calculations diverge. One of the advantages claimed for Dirac mean field calculations over nonrelativistic ones has been the fact that they yield reasonable saturation properties without the necessity of a three-body interaction. This is usually credited to the three-body effects introduced by virtual scattering through the Dirac sea states. These are included, in part, through the Dirac form of the self-energy in our calculations. However, we have explicitly excluded their contribution to the Brueckner scattering kernel. Dirac-Brueckner calculations in which both the positive and negative energy states are included in the scattering kernel result in less binding than those that include only the positive-energy ones
Roles of nuclear power system in the presence of uncertainties from global warming
International Nuclear Information System (INIS)
Kiriyama, Eriko; Iwata, Shuichi
2005-01-01
Environmental 'bads' like carbon dioxide are not simply incorporated in the market system. The costs involved, however, do not really reflect the inherent value of the environment, or what it is worth to them. This study focuses on the uncertainty of CO 2 emission credits. Assigning economic values to environmental goods and services is complex, but it is an area that is receiving considerable attention from environmental economists. The purpose of this study is to analyze the value of an investment in power generation assets that do not emit CO 2 . To deal with the CO 2 emission credit, we built new models based on the real option model by Pindyck (2000). In the modern, market-based financial systems that dominate the global economy, the value of a resource is represented by the price that an individual or a group is willing to pay for it. Managing CO 2 emission limitations will be a critical aspect of power generation systems. And it will be increasingly so as the emphasis on global environmental issues continues to rise. In order to secure the effectiveness of measures against global warming, we should reconsider the role of nuclear power systems. (author)
3D2 pairing in asymmetric nuclear matter
International Nuclear Information System (INIS)
Alm, T.
1996-01-01
The superfluid 3 D 2 pairing instability in isospin-asymmetric nuclear matter is studied, using the Paris nucleon-nucleon interaction as an input. It is found that the critical temperature associated with the transition to the superfluid phase becomes strongly suppressed with increasing isospin asymmetry, and vanishes for asymmetry parameter values α (≡(n n -n p )/(n n +n p )) that are larger than several percent. It is shown that for neutron star models based on relativistic, field-theoretical equations of state, a large fraction of their interior may exist in a 3 D 2 -paired superfluid phase. The implications of such a 3 D 2 superfluid in massive neutron stars is discussed with respect to observable pulsar phenomena. Another interesting phenomenon, discussed in the paper, concerns the numerical finding of two critical superfluid temperatures for a given density in the case of isospin-asymmetric matter. Using the BCS cut-off ansatz, a mathematical expression for the critical temperature is derived which confirms this finding analytically. (orig.)
Short-range correlations in quark and nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Froemel, Frank
2007-06-15
In the first part of this thesis, the role of short-range correlations in quark matter is explored within the framework of the Nambu-Jona-Lasinio model. Starting from a next-to-leading order expansion in the inverse number of the quark colors, a fully self-consistent model constructed that employs the close relations between spectral functions and self-energies. In contrast to the usual quasiparticle approximations, this approach allows the investigation of the collisional broadening of the quark spectral function. Numerical calculations at various chemical potentials and zero temperature show that the short-range correlations do not only induce a finite width of the spectral function but also have some influence on the structure of the chiral phase transition. In the second part of this thesis, the temperature and density dependence of the nucleon spectral function in symmetric nuclear matter is investigated. The short-range correlations can be well described by a simple, self-consistent model on the one-particle-two-hole and two-particle-one-hole level (1p2h, 2p1h). The thermodynamically consistent description of the mean-field properties of the nucleons is ensured by incorporating a Skyrme-type potential. Calculations at temperatures and densities that can also be found in heavy-ion collisions or supernova explosions and the formation of neutron stars show that the correlations saturate at high temperatures and densities. (orig.)
Many body effects in nuclear matter QCD sum rules
Drukarev, E. G.; Ryskin, M. G.; Sadovnikova, V. A.
2017-12-01
We calculate the single-particle nucleon characteristics in symmetric nuclear matter with inclusion of the 3N and 4N interactions. We calculated the contribution of the 3N interactions earlier, now we add that of the 4N ones. The contribution of the 4N forces to nucleon self energies is expressed in terms of the nonlocal scalar condensate (d = 3) and of the configurations of the vector-scalar and the scalar-scalar quark condensates (d = 6) in which two diquark operators act on two different nucleons of the matter.These four-quark condensates are obtained in the model-independent way. The density dependence of the nucleon effective mass, of the vector self energy and of the single-particle potential energy are obtained. We traced the dependence of the nucleon characteristics on the actual value of the pion-nucleon sigma term. We obtained also the nucleon characteristics in terms of the quasifree nucleons, with the noninteracting nucleons surrounded by their pion clouds as the starting point. This approach leads to strict hierarchy of the many body forces.
2010-03-09
... NUCLEAR REGULATORY COMMISSION [Docket No. 05000271; License No. DPR-28; EA-10-034; NRC-2010-0089] In the Matter of Entergy Nuclear Operations; Vermont Yankee Nuclear Power Station; Demand for... this Demand for Information, the following information, in writing, and under oath or affirmation: 1...
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.)
Nuclear matter in relativistic mean field theory with isovector scalar meson.
Energy Technology Data Exchange (ETDEWEB)
Kubis, S.; Kutschera, M. [Institute of Nuclear Physics, Cracow (Poland)
1996-12-01
Relativistic mean field (RMF) theory of nuclear matter with the isovector scalar mean field corresponding to the {delta}-meson [a{sub 0}(980)] is studied. While the {delta}-meson field vanishes in symmetric nuclear matter, it can influence properties of asymmetric nuclear matter in neutron stars. The RMF contribution due to {delta}-field to the nuclear symmetry energy is negative. To fit the empirical value, E{sub s}{approx}30 MeV, a stronger {rho}-meson coupling is required than in absence of the {delta}-field. The energy per particle of neutron star matter is than larger at high densities than the one with no {delta}-field included. Also, the proton fraction of {beta}-stable matter increases. Splitting of proton and neutron effective masses due to the {delta}-field can affect transport properties of neutron star matter. (author). 4 refs, 6 figs.
Nuclear matter in relativistic mean field theory with isovector scalar meson
International Nuclear Information System (INIS)
Kubis, S.; Kutschera, M.
1996-12-01
Relativistic mean field (RMF) theory of nuclear matter with the isovector scalar mean field corresponding to the δ-meson [a 0 (980)] is studied. While the δ-meson field vanishes in symmetric nuclear matter, it can influence properties of asymmetric nuclear matter in neutron stars. The RMF contribution due to δ-field to the nuclear symmetry energy is negative. To fit the empirical value, E s ∼30 MeV, a stronger ρ-meson coupling is required than in absence of the δ-field. The energy per particle of neutron star matter is than larger at high densities than the one with no δ-field included. Also, the proton fraction of β-stable matter increases. Splitting of proton and neutron effective masses due to the δ-field can affect transport properties of neutron star matter. (author). 4 refs, 6 figs
International Nuclear Information System (INIS)
Koniges, A.; Liu, W.; Barnard, J.; Friedman, A.; Logan, G.; Eder, D.; Fisher, A.; Masters, N.; Bertozzi, A.
2013-01-01
The Neutralized Drift Compression Experiment II (NDCX II) is an induction accelerator planned for initial commissioning in 2012. The final design calls for a 3 MeV, Li + ion beam, delivered in a bunch with characteristic pulse duration of 1 ns, and transverse dimension of order 1 mm. The NDCX II will be used in studies of material in the warm dense matter (WDM) regime, and ion beam/hydrodynamic coupling experiments relevant to heavy ion based inertial fusion energy. We discuss recent efforts to adapt the 3D ALE-AMR code to model WDM experiments on NDCX II. The code, which combines Arbitrary Lagrangian Eulerian (ALE) hydrodynamics with Adaptive Mesh Refinement (AMR), has physics models that include ion deposition, radiation hydrodynamics, thermal diffusion, anisotropic material strength with material time history, and advanced models for fragmentation. Experiments at NDCX-II will explore the process of bubble and droplet formation (two-phase expansion) of superheated metal solids using ion beams. Experiments at higher temperatures will explore equation of state and heavy ion fusion beam-to-target energy coupling efficiency. Ion beams allow precise control of local beam energy deposition providing uniform volumetric heating on a timescale shorter than that of hydrodynamic expansion. We also briefly discuss the effects of the move to exascale computing and related computational changes on general modeling codes in fusion. (authors)
Multi-charge-state molecular dynamics and self-diffusion coefficient in the warm dense matter regime
Fu, Yongsheng; Hou, Yong; Kang, Dongdong; Gao, Cheng; Jin, Fengtao; Yuan, Jianmin
2018-01-01
We present a multi-ion molecular dynamics (MIMD) simulation and apply it to calculating the self-diffusion coefficients of ions with different charge-states in the warm dense matter (WDM) regime. First, the method is used for the self-consistent calculation of electron structures of different charge-state ions in the ion sphere, with the ion-sphere radii being determined by the plasma density and the ion charges. The ionic fraction is then obtained by solving the Saha equation, taking account of interactions among different charge-state ions in the system, and ion-ion pair potentials are computed using the modified Gordon-Kim method in the framework of temperature-dependent density functional theory on the basis of the electron structures. Finally, MIMD is used to calculate ionic self-diffusion coefficients from the velocity correlation function according to the Green-Kubo relation. A comparison with the results of the average-atom model shows that different statistical processes will influence the ionic diffusion coefficient in the WDM regime.
Teiji, KUNIHIRO; Tatsuyuki, TAKATSUKA; Ryozo, TAMAGAKI; Department of National Sciences, Ryukoku University; College of Humanities and Social Sciences, Iwate University; Department of Physics, Kyoto University
1985-01-01
Pion condensation in the symmetric nuclear matter is investigated on the basis of the ALS (alternating-layer-spin) model which provides a good description for the π^0 condensation. We perform energy calculations in a realistic way where the isobar (Δ)-mixing, the short range effects and the exchange energy of the interaction are taken into account. The Δ-mixing effect is built in the model state as previously done in the neutron matter. We preferentially employ G-0 force of Sprung and Banerje...
International Nuclear Information System (INIS)
Sakata, F.; Marumori, T.; Hashimoto, Y.; Tsukuma, H.; Yamamoto, Y.; Terasaki, J.; Iwasawa, Y.; Itabashi, H.
1992-01-01
Since the research field of nuclear physics is expanding rapidly, it is becoming more imperative to develop the microscopie theory of nuclear matter physics which provides us with a unified understanding of diverse phenomena exhibited by nuclei. An estabishment of various stable mean-fields in nuclei allows us to develop the microscopie theory of nuclear collective dynamics within the mean-field approximation. The classical-level theory of nuclear collective dynamics is developed by exploiting the symplectic structure of the timedependent Hartree-Fock (TDHF)-manifold. The importance of exploring the single-particle dynamics, e.g. the level-crossing dynamics in connection with the classical order-to-chaos transition mechanism is pointed out. Since the classical-level theory os directly related to the full quantum mechanical boson expansion theory via the symplectic structure of the TDHF-manifold, the quantum theory of nuclear collective dynamics is developed at the dictation of what os developed on the classical-level theory. The quantum theory thus formulated enables us to introduce the quantum integrability and quantum chaoticity for individual eigenstates. The inter-relationship between the classical-level and quantum theories of nuclear collective dynamics might play a decisive role in developing the quantum theory of many-body problems. (orig.)
International Nuclear Information System (INIS)
1979-01-01
These Regulations prescribe, for the purposes of the definition of 'excepted matter' in the Nuclear Installations Act 1965, certain specified quantities and forms of nuclear matter, and supersede the Nuclear Installations (excepted Matter) Regulations 1965. They bring the definition of excepted matter in those Regulations into line with the decisions of 27 October 1977 of the OECD Nuclear Energy Agency's Steering Committee excluding certain kinds and quantities of nuclear substances from the scope of the Paris Convention on Third Party Liability in the Field of Nuclear Energy. Compared with the 1965 Regulations, the principal changes in relation to consignments are that activity limits and packing requirements now take account of the most recent IAEA Regulations. (NEA) [fr
Yuan, Xiaochun; Si, Youtao; Lin, Weisheng; Yang, Jingqing; Wang, Zheng; Zhang, Qiufang; Qian, Wei; Yang, Yusheng
2018-01-01
Increasing temperature and nitrogen (N) deposition are two large-scale changes projected to occur over the coming decades. The effects of these changes on dissolved organic matter (DOM) are largely unknown. This study aimed to assess the effects of warming and N addition on the quantity and quality of DOM from a subtropical Cunninghamia lanceolata plantation. Between 2014 and 2016, soil solutions were collected from 0–15, 15–30, and 30–60 cm depths by using a negative pressure sampling method. The quantity and quality of DOM were measured under six different treatments. The spectra showed that the DOM of the forest soil solution mainly consisted of aromatic protein-like components, microbial degradation products, and negligible amounts of humic-like substances. Warming, N addition, and warming + N addition significantly inhibited the concentration of dissolved organic carbon (DOC) in the surface (0–15 cm) soil solution. Our results suggested that warming reduced the amount of DOM originating from microbes. The decrease in protein and carboxylic acid contents was mostly attributed to the reduction of DOC following N addition. The warming + N addition treatment showed an interactive effect rather than an additive effect. Thus, short-term warming and warming + N addition decreased the quantity of DOM and facilitated the migration of nutrients to deeper soils. Further, N addition increased the complexity of the DOM structure. Hence, the loss of soil nutrients and the rational application of N need to be considered in order to prevent the accumulation of N compounds in soil. PMID:29360853
International Nuclear Information System (INIS)
Koniges, A.; Eder, E.; Liu, W.; Barnard, J.; Friedman, A.; Logan, G.; Fisher, A.; Masers, N.; Bertozzi, A.
2011-01-01
The Neutralized Drift Compression Experiment II (NDCX II) is an induction accelerator planned for initial commissioning in 2012. The final design calls for a 3 MeV, Li+ ion beam, delivered in a bunch with characteristic pulse duration of 1 ns, and transverse dimension of order 1 mm. The NDCX II will be used in studies of material in the warm dense matter (WDM) regime, and ion beam/hydrodynamic coupling experiments relevant to heavy ion based inertial fusion energy. We discuss recent efforts to adapt the 3D ALE-AMR code to model WDM experiments on NDCX II. The code, which combines Arbitrary Lagrangian Eulerian (ALE) hydrodynamics with Adaptive Mesh Refinement (AMR), has physics models that include ion deposition, radiation hydrodynamics, thermal diffusion, anisotropic material strength with material time history, and advanced models for fragmentation. Experiments at NDCX-II will explore the process of bubble and droplet formation (two-phase expansion) of superheated metal solids using ion beams. Experiments at higher temperatures will explore equation of state and heavy ion fusion beam-to-target energy coupling efficiency. Ion beams allow precise control of local beam energy deposition providing uniform volumetric heating on a timescale shorter than that of hydrodynamic expansion. The ALE-AMR code does not have any export control restrictions and is currently running at the National Energy Research Scientific Computing Center (NERSC) at LBNL and has been shown to scale well to thousands of CPUs. New surface tension models that are being implemented and applied to WDM experiments. Some of the approaches use a diffuse interface surface tension model that is based on the advective Cahn-Hilliard equations, which allows for droplet breakup in divergent velocity fields without the need for imposed perturbations. Other methods require seeding or other methods for droplet breakup. We also briefly discuss the effects of the move to exascale computing and related
Temperature dependence of single-particle properties in nuclear matter
International Nuclear Information System (INIS)
Zuo, W.; Lu, G.C.; Li, Z.H.; Lombardo, U.; Schulze, H.-J.
2006-01-01
The single-nucleon potential in hot nuclear matter is investigated in the framework of the Brueckner theory by adopting the realistic Argonne V 18 or Nijmegen 93 two-body nucleon-nucleon interaction supplemented by a microscopic three-body force. The rearrangement contribution to the single-particle potential induced by the ground state correlations is calculated in terms of the hole-line expansion of the mass operator and provides a significant repulsive contribution in the low-momentum region around and below the Fermi surface. Increasing temperature leads to a reduction of the effect, while increasing density makes it become stronger. The three-body force suppresses somewhat the ground state correlations due to its strong short-range repulsion, increasing with density. Inclusion of the three-body force contribution results in a quite different temperature dependence of the single-particle potential at high enough densities as compared to that adopting the pure two-body force. The effects of three-body force and ground state correlations on the nucleon effective mass are also discussed
Neutrino propagation in neutron matter and the nuclear equation of state
Margueron, J; Nguyen Van Giai; Jiang, W
2001-01-01
We study the propagation of neutrinos inside dense matter under the conditions prevailing in a proto-neutron star. Equations of state obtained with different nuclear effective interactions (Skyrme type and Gogny type) are first discussed. It is found that for many interactions, spin and/or isospin instabilities occur at densities larger than the saturation density of nuclear matter. From this study we select two representative interactions, SLy230b and D1P. We calculate the response functions in pure neutron matter where nuclear correlations are described at the Hartree-Fock plus RPA level. These response functions allow us to evaluate neutrino mean free paths corresponding to neutral current processes.
Chiral symmetry, scalar field and confinement: from nucleon structure to nuclear matter
International Nuclear Information System (INIS)
Chanfray, Guy; Ericson, Magda
2010-01-01
We discuss the relevance of the scalar modes appearing in chiral theories with spontaneous symmetry breaking such as the NJL model for nuclear matter studies. We show that it depends on the relative role of chiral symmetry breaking and confinement in the nucleon mass origin. It is only in the case of a mixed origin that nuclear matter can be stable and reach saturation. We describe models of nucleon structure where this balance is achieved. We show how chiral constarints and confinement modify the QCD sum rules for the mass evolution in nuclear matter.
Bedford, Daniel
2016-01-01
Educators seeking to address global warming in their classrooms face numerous challenges, including the question of whether student opinions about anthropogenic global warming (AGW) can change in response to increased knowledge about the climate system. This article analyzes survey responses from 458 students at a primarily undergraduate…
Probing warm dense lithium by inelastic X-ray scattering
Energy Technology Data Exchange (ETDEWEB)
Garcia Saiz, E; Riley, D [School of Mathematics and Physics, Queen' s University of Belfast, Belfast (United Kingdom); Gregori, G [Clarendon Laboratory, University of Oxford, Parks Road, Oxford (United Kingdom); Gregori, G; Clarke, R J; Neely, D; Notley, M M; Spindloe, C [Central Laser Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OX (United Kingdom); Gericke, D O; Vorberger, J; Wunsch, K [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry (United Kingdom); Barbrel, B; Koenig, M [Laboratoire pour l' Utilisation des Laser Intenses, Ecole Polytechnique - Universite Paris-6, 91 - Palaiseau (France); Freeman, R R; Weber, R L; Van Woerkom, L [Department of Physics, The Ohio State University, Columbus, Ohio (United States); Glenzer, S H; Landen, O L; Neumayer, P; Price, D [Lawrence Livermore National Laboratory, Livermore, California (United States); Khattak, F Y [Department of Physics, Kohat University of Science and Technology, Kohat-26000, NWFP (Pakistan); Pelka, A; Roth, M; Schollmeier, M [Institut fur Kernphysik, Technische Universitat Darmstadt (Germany)
2008-10-15
One of the grand challenges of contemporary physics is understanding strongly interacting quantum systems comprising such diverse examples as ultracold atoms in traps, electrons in high-temperature superconductors and nuclear matter. Warm dense matter, defined by temperatures of a few electron volts and densities comparable with solids, is a complex state of such interacting matter. Moreover, the study of warm dense matter states has practical applications for controlled thermonuclear fusion, where it is encountered during the implosion phase, and it also represents laboratory analogues of astrophysical environments found in the core of planets and the crusts of old stars. Here we demonstrate how warm dense matter states can be diagnosed and structural properties can be obtained by inelastic X-ray scattering measurements on a compressed lithium sample. Combining experiments and ab initio simulations enables us to determine its microscopic state and to evaluate more approximate theoretical models for the ionic structure. (authors)
Can tonne-scale direct detection experiments discover nuclear dark matter?
Energy Technology Data Exchange (ETDEWEB)
Butcher, Alistair; Kirk, Russell; Monroe, Jocelyn; West, Stephen M., E-mail: Alistair.Butcher.2010@live.rhul.ac.uk, E-mail: Russell.Kirk.2008@live.rhul.ac.uk, E-mail: Jocelyn.Monroe@rhul.ac.uk, E-mail: Stephen.West@rhul.ac.uk [Department of Physics, Royal Holloway University of London, Egham, Surrey, TW20 0EX (United Kingdom)
2017-10-01
Models of nuclear dark matter propose that the dark sector contains large composite states consisting of dark nucleons in analogy to Standard Model nuclei. We examine the direct detection phenomenology of a particular class of nuclear dark matter model at the current generation of tonne-scale liquid noble experiments, in particular DEAP-3600 and XENON1T. In our chosen nuclear dark matter scenario distinctive features arise in the recoil energy spectra due to the non-point-like nature of the composite dark matter state. We calculate the number of events required to distinguish these spectra from those of a standard point-like WIMP state with a decaying exponential recoil spectrum. In the most favourable regions of nuclear dark matter parameter space, we find that a few tens of events are needed to distinguish nuclear dark matter from WIMPs at the 3 σ level in a single experiment. Given the total exposure time of DEAP-3600 and XENON1T we find that at best a 2 σ distinction is possible by these experiments individually, while 3 σ sensitivity is reached for a range of parameters by the combination of the two experiments. We show that future upgrades of these experiments have potential to distinguish a large range of nuclear dark matter models from that of a WIMP at greater than 3 σ .
Can tonne-scale direct detection experiments discover nuclear dark matter?
International Nuclear Information System (INIS)
Butcher, Alistair; Kirk, Russell; Monroe, Jocelyn; West, Stephen M.
2017-01-01
Models of nuclear dark matter propose that the dark sector contains large composite states consisting of dark nucleons in analogy to Standard Model nuclei. We examine the direct detection phenomenology of a particular class of nuclear dark matter model at the current generation of tonne-scale liquid noble experiments, in particular DEAP-3600 and XENON1T. In our chosen nuclear dark matter scenario distinctive features arise in the recoil energy spectra due to the non-point-like nature of the composite dark matter state. We calculate the number of events required to distinguish these spectra from those of a standard point-like WIMP state with a decaying exponential recoil spectrum. In the most favourable regions of nuclear dark matter parameter space, we find that a few tens of events are needed to distinguish nuclear dark matter from WIMPs at the 3 σ level in a single experiment. Given the total exposure time of DEAP-3600 and XENON1T we find that at best a 2 σ distinction is possible by these experiments individually, while 3 σ sensitivity is reached for a range of parameters by the combination of the two experiments. We show that future upgrades of these experiments have potential to distinguish a large range of nuclear dark matter models from that of a WIMP at greater than 3 σ .
Hyperons in nuclear matter from SU(3) chiral effective field theory
Energy Technology Data Exchange (ETDEWEB)
Petschauer, S.; Kaiser, N. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Haidenbauer, J. [Institut fuer Kernphysik, Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich Center for Hadron Physics, Juelich (Germany); Meissner, Ulf G. [Institut fuer Kernphysik, Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich Center for Hadron Physics, Juelich (Germany); Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Weise, W. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Villa Tambosi, ECT, Villazzano (Trento) (Italy)
2016-01-15
Brueckner theory is used to investigate the properties of hyperons in nuclear matter. The hyperon-nucleon interaction is taken from chiral effective field theory at next-to-leading order with SU(3) symmetric low-energy constants. Furthermore, the underlying nucleon-nucleon interaction is also derived within chiral effective field theory. We present the single-particle potentials of Λ and Σ hyperons in symmetric and asymmetric nuclear matter computed with the continuous choice for intermediate spectra. The results are in good agreement with the empirical information. In particular, our calculation gives a repulsive Σ-nuclear potential and a weak Λ-nuclear spin-orbit force. (orig.)
Tahir, Naeem Ahmad; Blanco Sancho, Juan; Schmidt, Ruediger; Shutov, Alaxander; Burkart, Florian; Wollmann, Daniel; Piriz, Antonio Roberto
2013-10-01
Numerical simulations have shown that the range of 7 TeV LHC protons in solid matter will be significantly increased due to hydrodynamic tunneling. For example, in solid copper and solid carbon, these protons and the shower can penetrate up to 35 m and 25 m, respectively. However, their corresponding static range in the two materials is 1 m and 3 m, respectively. This will have important implications on machine protection design. In order to validate these simulation results, experiments have been performed at the CERN HiRadMat facility using the 440 GeV SPS proton beam irradiating solid copper cylindrical target. The phenomenon of hydrodynamic tunneling has been experimentally confirmed and good agreement has been found between the simulations and the experimental results. A very interesting outcome of this work is that the HiRadMat facility can be used to generate High Energy Density matter including Warm Dense Matter and strongly coupled plasmas in the laboratory.
International Nuclear Information System (INIS)
Messina, A.
2000-01-01
This book contains 102 scientific contributions in the areas of nuclear and condensed matter physics. The conference was attended by 144 physicists, most of them belonging to the Sicilian Universities of Palermo, Catania and Messina
Influence of flow constraints on the properties of the critical endpoint of symmetric nuclear matter
Ivanytskyi, A. I.; Bugaev, K. A.; Sagun, V. V.; Bravina, L. V.; Zabrodin, E. E.
2018-06-01
We propose a novel family of equations of state for symmetric nuclear matter based on the induced surface tension concept for the hard-core repulsion. It is shown that having only four adjustable parameters the suggested equations of state can, simultaneously, reproduce not only the main properties of the nuclear matter ground state, but the proton flow constraint up its maximal particle number densities. Varying the model parameters we carefully examine the range of values of incompressibility constant of normal nuclear matter and its critical temperature, which are consistent with the proton flow constraint. This analysis allows us to show that the physically most justified value of nuclear matter critical temperature is 15.5-18 MeV, the incompressibility constant is 270-315 MeV and the hard-core radius of nucleons is less than 0.4 fm.
Nuclear matter saturation in a U(1) circle-times chiral model
International Nuclear Information System (INIS)
Lin, Wei
1989-01-01
The mean-field approximation in the U(1) circle-times chiral model for nuclear matter maturation is reviewed. Results show that it cannot be the correct saturation mechanism. It is argued that in this chiral model, other than the fact the ω mass can depend on the density of nuclear matter, saturation is still quite like the Walecka picture. 16 refs., 3 figs
Properties of nuclear and neutron matter using D1 Gogny force
International Nuclear Information System (INIS)
Mansour, H.M.M.; Ramadan, Kh.A.; Hammad, M.
2004-01-01
In the present work, we investigate the equation of state of hot and cold nuclear and neutron matter using the Gogny effective interaction. The binding energy per particle, symmetry energies, free energy, and pressure are calculated as a function of the density ρ, fm -3 , for the nuclear and neutron matter. The results are comparable with previous theoretical estimates using the Seyler-Blanchard effective interaction and the famous calculation of Friedman and Pandharipande using a realistic interaction
Softness of Nuclear Matter and the Production of Strange Particles in Neutron Stars
Institute of Scientific and Technical Information of China (English)
陈伟; 文德华; 刘良钢
2003-01-01
In the various models, we study the influences of the softness of nuclear matter, the vacuum fluctuation ofnucleons and σ mesons on the production of strange particles in neutron stars. Wefind that the stiffer the nuclear matter is, the more easily the strange particles is produced in neutron stars. The vacuum fluctuation of nucleons has large effect on strange particle production while that of σ meson has little effect on it.
Role of isospin in nuclear-matter liquid-gas phase transition
International Nuclear Information System (INIS)
Ducoin, C.
2006-10-01
Nuclear matter presents a phase transition of the liquid-gas type. This well-known feature is due to the nuclear interaction profile (mean-range attractive, short-range repulsive). Symmetric-nuclear-matter thermodynamics is thus analogous to that of a Van der Waals fluid. The study shows up to be more complex in the case of asymmetric matter, composed of neutrons and protons in an arbitrary proportion. Isospin, which distinguishes both constituents, gives a measure of this proportion. Studying asymmetric matter, isospin is an additional degree of freedom, which means one more dimension to consider in the space of observables. The nuclear liquid-gas transition is associated with the multi-fragmentation phenomenon observed in heavy-ion collisions, and to compact-star physics: the involved systems are neutron rich, so they are affected by the isospin degree of freedom. The present work is a theoretical study of isospin effects which appear in the asymmetric nuclear matter liquid-gas phase transition. A mean-field approach is used, with a Skyrme nuclear effective interaction. We demonstrate the presence of a first-order phase transition for asymmetric matter, and study the isospin distillation phenomenon associated with this transition. The case of phase separation at thermodynamic equilibrium is compared to spinodal decomposition. Finite size effects are addressed, as well as the influence of the electron gas which is present in the astrophysical context. (author)
Critical behavior of mean-field hadronic models for warm nuclear matter
International Nuclear Information System (INIS)
Silva, J.B.; Lourenco, O.; Delfino, A.; Martins, J.S. Sa; Dutra, M.
2008-01-01
We study a set of hadronic mean-field models in the liquid-gas phase transition regime and calculate their critical parameters. The discussion is unified by scaling the coexistence curves in terms of these critical parameters. We study the models close to spinodal points, where they also present critical behavior. Inspired by signals of criticality shown in fragmentation experiments, we analyze two different scenarios in which such behavior would be expected: (i) the stability limits of a metastable system with vanishing external pressure; and (ii) the critical point of a gas-liquid phase equilibrium system for which the Maxwell construction applies. Spinodal and coexistence curves show the regions in which model dependence arises. Unexpectedly, this model dependence does not manifest if one calculates the thermal incompressibility of the models
Some Recent Progress on Quark Pairings in Dense Quark and Nuclear Matter
International Nuclear Information System (INIS)
Pang Jinyi; Wang Jincheng; Wang Qun
2012-01-01
In this review article we give a brief overview on some recent progress in quark pairings in dense quark/nuclear matter mostly developed in the past five years. We focus on following aspects in particular: the BCS-BEC crossover in the CSC phase, the baryon formation and dissociation in dense quark/nuclear matter, the Ginzburg-Landau theory for three-flavor dense matter with U A (1) anomaly, and the collective and Nambu-Goldstone modes for the spin-one CSC. (physics of elementary particles and fields)
Non-Abelian behavior of α bosons in cold symmetric nuclear matter
International Nuclear Information System (INIS)
Zheng Hua; Bonasera, Aldo
2011-01-01
The ground-state energy of infinite symmetric nuclear matter is usually described by strongly interacting nucleons obeying the Pauli exclusion principle. We can imagine a unitary transformation which groups four nonidentical nucleons (i.e., with different spin and isospin) close in coordinate space. Those nucleons, being nonidentical, do not obey the Pauli principle, thus their relative momenta are negligibly small (just to fulfill the Heisenberg principle). Such a cluster can be identified with an α boson. But in dense nuclear matter, those α particles still obey the Pauli principle since are constituted of fermions. The ground state energy of nuclear matter α clusters is the same as for nucleons, thus it is degenerate. We could think of α particles as vortices which can now braid, for instance making 8 Be which leave the ground state energy unchanged. Further braiding to heavier clusters ( 12 C, 16 O,...) could give a different representation of the ground state at no energy cost. In contrast d-like clusters (i.e., N=Z odd-odd nuclei, where N and Z are the neutron and proton number, respectively) cannot describe the ground state of nuclear matter and can be formed at high excitation energies (or temperatures) only. We show that even-even, N=Z, clusters could be classified as non-Abelian states of matter. As a consequence an α condensate in nuclear matter might be hindered by the Fermi motion, while it could be possible a condensate of 8 Be or heavier clusters.
Sound-like collective mode excitation with pion absorption in nuclear matter
International Nuclear Information System (INIS)
Qiu Xijiun; Shen Jianguo; Huang Lingfang
1985-01-01
The relativistic mean field theory consistent with bulk properties of nuclear matter is extended to study the excitations of the sound-like collective modes in nuclear matter. Corresponding relativistic mean field equations are solved numerically and self-consistently. The effective mass of nucleon, the speed of the sound and the amplitude of the sound-like solution are calculated. When the nuclear density is near or greater than the saturation density, the sound-like non-trivial solution could be found
Isospin and momentum dependence of liquid-gas phase transition in hot asymmetric nuclear matter
International Nuclear Information System (INIS)
Xu, Jun; Ma, Hongru; Chen, Liewen; Li, Baoan
2008-01-01
The liquid-gas phase transition in hot neutron-rich nuclear matter is investigated within a self-consistent thermal model using different interactions with or without isospin and/or momentum dependence. The boundary of the phase-coexistence region is shown to be sensitive to the density dependence of the nuclear symmetry energy as well as the isospin and momentum dependence of the nuclear interaction. (author)
The matter of probability controlling melting of nuclear ship reactor
International Nuclear Information System (INIS)
Pihowicz, W.; Sobczyk, S.
2008-01-01
In the first part of this work beside description of split power, power of radioactivity disintegration and afterpower and its ability to extinguish, the genera condition of melting nuclear reactor core and its detailed versions were described. This paper also include the description of consequences melting nuclear reactor core both in case of stationary and mobile (ship) reactor and underline substantial differences. Next, fulfilled with succeed, control under melting of stationary nuclear reactor core was characterized.The middle part describe author's idea of controlling melting of nuclear ship reactor core. It is based on: - the suggestion of prevention pressure's untightness in safety tank of nuclear ship reactor by '' corium '' - and the suggestion of preventing walls of this tank from melting by '' corium ''. In the end the technological and construction barriers of the prevention from melting nuclear ship reactor and draw conclusions was presented. (author)
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)
Hou, Yong; Fu, Yongsheng; Bredow, Richard; Kang, Dongdong; Redmer, Ronald; Yuan, Jianmin
2017-03-01
The average-atom model combined with the hyper-netted chain approximation is an efficient tool for electronic and ionic structure calculations for warm dense matter. Here we generalize this method in order to describe non-equilibrium states with different electron and ion temperature as produced in laser-matter interactions on ultra-short time scales. In particular, the electron-ion and ion-ion correlation effects are considered when calculating the electron structure. We derive an effective ion-ion pair-potential using the electron densities in the framework of temperature-depended density functional theory. Using this ion-ion potential we perform molecular dynamics simulations in order to determine the ionic transport properties such as the ionic diffusion coefficient and the shear viscosity through the ionic velocity autocorrelation functions.
International Nuclear Information System (INIS)
Cornish, Emma
2000-01-01
The nuclear industry sits along side the renewable energy sector in its role as a non carbon emitting technology. But persuading international political leaders of this fact presents a challenge. Generating electricity from nuclear fuel avoids at least 2 billion tonnes of carbon dioxide every year through its 16% share of world wide electricity generation. Nuclear energy is essential to minimising greenhouse gas emissions. This presentation highlights the main issues resulting from the climate change negotiations that are highly relevant to the industry; explains the activities of the International Nuclear Forum and our interaction with the delegates to the process; outlines future activities. The International Nuclear Forum (INF) was formed to provide a collective voice lobbying for nuclear at the climate change negotiations. It's internationally representative of the industry and comprises of: the Uranium Institute; the Nuclear Energy Institute; the Japan Atomic Industry Forum; the Canadian Nuclear Association; the European Nuclear Society, and Foratom. All are accredited non governmental observers to the negotiations of the United Nations Framework Convention on Climate Change
Chiral symmetry and nuclear matter equation of state
Indian Academy of Sciences (India)
In other words, we want to probe if, in the context of a two-body force model, the empirical ... action occurs by the surrounding nucleons through Pauli blocking and the nuclear mean field. Nuclear ... sigma and delta have been considered.
Modification of the omega-meson lifetime in nuclear matter
Kotulla, M.; Trnka, D.; Muehlich, P.; Anton, G.; Bacelar, J. C. S.; Bartholomy, O.; Bayadilov, D.; Beloglazov, Y. A.; Bogendoerfer, R.; Castelijns, R.; Crede, V.; Dutz, H.; Ehmanns, A.; Elsner, D.; Ewald, R.; Fabry, I.; Fuchs, M.; Essig, K.; Funke, Ch.; Gothe, R.; Gregor, R.; Gridnev, A. B.; Gutz, E.; Hoeffgen, S.; Hoffmeister, P.; Horn, I.; Hoessl, J.; Jaegle, I.; Junkersfeld, J.; Kalinowsky, H.; Klein, Frank; Klein, Fritz; Klempt, E.; Konrad, M.; Kopf, B.; Krusche, B.; Langheinrich, J.; Loehner, H.; Lopatin, I. V.; Lotz, J.; Lugert, S.; Menze, D.; Messchendorp, J. G.; Mertens, T.; Metag, V.; Mosel, U.; Nanova, M.; Novotny, R.; Ostrick, M.; Pant, L. M.; van Pee, H.; Pfeiffer, M.; Roy, A.; Radkov, A.; Schadmand, S.; Schmidt, Ch.; Schmieden, H.; Schoch, B.; Shende, S.; Suft, G.; Sumachev, V. V.; Szczepanek, T.; Suele, A.; Thoma, U.; Varma, R.; Walther, D.; Weinheimer, Ch.; Wendel, Ch.
2008-01-01
Information on hadron properties in the nuclear medium has been derived from the photoproduction of omega mesons on the nuclei C, Ca, Nb, and Pb using the Crystal Barrel/TAPS detector at the ELSA tagged photon facility in Bonn. The dependence of the omega-meson cross section on the nuclear mass
Tritium in organic matter around Krsko Nuclear Power Plant
International Nuclear Information System (INIS)
Kristof, Romana; Zorko, Benjamin; Kozar Logar, Jasmina; Kosenina, Suzana
2017-01-01
The aim of the research was to obtain first results of tritium in the organic matter of environmental samples in the vicinity of Krsko NPP. The emphasis was on the layout of suitable sampling network of crops and fruits in nearby agricultural area. Method for determination of tritium in organic matter in the form of Tissue Free Water Tritium (TFWT) and Organically Bound Tritium (OBT) has been implemented. Capabilities of the methods were tested on real environmental samples and its findings were compared to modeled activities of tritium from atmospheric releases and literature based results of TFWT and OBT. (author)
Isospin-dependent properties of asymmetric nuclear matter in relativistic mean field models
Chen, Lie-Wen; Ko, Che Ming; Li, Bao-An
2007-11-01
Using various relativistic mean-field models, including nonlinear ones with meson field self-interactions, models with density-dependent meson-nucleon couplings, and point-coupling models without meson fields, we have studied the isospin-dependent bulk and single-particle properties of asymmetric nuclear matter. In particular, we have determined the density dependence of nuclear symmetry energy from these different relativistic mean-field models and compared the results with the constraints recently extracted from analyses of experimental data on isospin diffusion and isotopic scaling in intermediate energy heavy-ion collisions as well as from measured isotopic dependence of the giant monopole resonances in even-A Sn isotopes. Among the 23 parameter sets in the relativistic mean-field model that are commonly used for nuclear structure studies, only a few are found to give symmetry energies that are consistent with the empirical constraints. We have also studied the nuclear symmetry potential and the isospin splitting of the nucleon effective mass in isospin asymmetric nuclear matter. We find that both the momentum dependence of the nuclear symmetry potential at fixed baryon density and the isospin splitting of the nucleon effective mass in neutron-rich nuclear matter depend not only on the nuclear interactions but also on the definition of the nucleon optical potential.
The future of the nuclear industry: a matter of communication
Energy Technology Data Exchange (ETDEWEB)
De Waal, H S
1993-11-01
Since the very first successes achieved by the early scientists the infant nuclear industry was plagued by an atmosphere of uncertainty, conflict, anxiety and expectations. After the initial euphoria the Chernobyl accident shocked public opinion and perspectives changed. Nuclear energy is experience by the public in three dimensions. Firstly there are the technical realities of the reactor and its fantastically reduced source of power. Secondly, there is a psychological and political meaning, including the association of modern technology with authority, government, and control. The third dimension is the product of old myths about `divine secrets`, mad scientists dreadful pollution and cosmic apocalypse. To a large extent the nuclear industry is at fault for these emotional connotations. An early lapse in the communication process can be blamed for many of the misconceptions. The nuclear industry lost an opportunity by sticking to `vagueness`. Recent trends show that a pattern of conditional acceptance is present in public opinion with regard to the nuclear industry. Possible solutions, including better communication, aggressive marketing, and the training of scientists to become communicators, are discussed. A study was done of community attitudes around Koeberg, and it is concluded that the public must be convinced of the fact that nuclear power is clean, safe, cheap and accepted as such by the industrially developed word. 62 refs., 13 figs.
The future of the nuclear industry: a matter of communication
International Nuclear Information System (INIS)
De Waal, H.S.
1993-11-01
Since the very first successes achieved by the early scientists the infant nuclear industry was plagued by an atmosphere of uncertainty, conflict, anxiety and expectations. After the initial euphoria the Chernobyl accident shocked public opinion and perspectives changed. Nuclear energy is experience by the public in three dimensions. Firstly there are the technical realities of the reactor and its fantastically reduced source of power. Secondly, there is a psychological and political meaning, including the association of modern technology with authority, government, and control. The third dimension is the product of old myths about 'divine secrets', mad scientists dreadful pollution and cosmic apocalypse. To a large extent the nuclear industry is at fault for these emotional connotations. An early lapse in the communication process can be blamed for many of the misconceptions. The nuclear industry lost an opportunity by sticking to 'vagueness'. Recent trends show that a pattern of conditional acceptance is present in public opinion with regard to the nuclear industry. Possible solutions, including better communication, aggressive marketing, and the training of scientists to become communicators, are discussed. A study was done of community attitudes around Koeberg, and it is concluded that the public must be convinced of the fact that nuclear power is clean, safe, cheap and accepted as such by the industrially developed word. 62 refs., 13 figs
Variational Calculation for the Equation of State of Hot Asymmetric Nuclear Matter
International Nuclear Information System (INIS)
Togashi, Hajime; Kanzawa, Hiroaki; Takano, Masatoshi
2010-01-01
We calculate the equation of state (EOS) of asymmetric nuclear matter at finite temperatures with the cluster variational method based on the realistic nuclear Hamiltonian composed of the AV18 and UIX nuclear potentials. The free energy is calculated with an extension of the variational method proposed by Schmidt and Pandharipande. The obtained thermodynamic quantities such as entropy, internal energy, pressure and chemical potential derived from the free energy are reasonable. It is also found that the present variational calculation is self-consistent. These thermodynamic quantities are essential ingredients in our project for constructing a new nuclear EOS applicable to supernova simulations.
Antiferromagnetic spin phase transition in nuclear matter with effective Gogny interaction
International Nuclear Information System (INIS)
Isayev, A.A.; Yang, J.
2004-01-01
The possibility of ferromagnetic and antiferromagnetic phase transitions in symmetric nuclear matter is analyzed within the framework of a Fermi liquid theory with the effective Gogny interaction. It is shown that at some critical density nuclear matter with the D1S effective force undergoes a phase transition to the antiferromagnetic spin state (opposite directions of neutron and proton spins). The self-consistent equations of spin polarized nuclear matter with the D1S force have no solutions corresponding to ferromagnetic spin ordering (the same direction of neutron and proton spins) and, hence, the ferromagnetic transition does not appear. The dependence of the antiferromagnetic spin polarization parameter as a function of density is found at zero temperature
Sigma-omega meson coupling and properties of nuclei and nuclear matter
International Nuclear Information System (INIS)
Haidari, Maryam M.; Sharma, Madan M.
2008-01-01
We have constructed a Lagrangian model with a coupling of σ and ω mesons in the relativistic mean-field theory. Properties of finite nuclei and nuclear matter are explored with the new Lagrangian model SIG-OM. The study shows that an excellent description of binding energies and charge radii of nuclei over a large range of isospin is achieved with SIG-OM. With an incompressibility of nuclear matter K=265 MeV, it is also able to describe the breathing-mode isoscalar giant monopole resonance energies appropriately. It is shown that the high-density behaviour of the equation of state of nuclear and neutron matter with the σ-ω coupling is much softer than that of the non-linear scalar coupling model
Baltar, Federico; Moran, Xose Anxelu G.; Lø nborg, Christian
2017-01-01
Extracellular enzymatic activities (EEAs) are the rate-limiting step in the degradation of organic matter. Extracellular enzymes can be found associated to cells or dissolved in the surrounding water. The proportion of cell-free EEA constitutes
Collective effects on transport coefficients of relativistic nuclear matter. Pt. 2
International Nuclear Information System (INIS)
Mornas, L.
1993-04-01
The transport coefficients (thermal conductivity, shear and bulk viscosities) of symmetric nuclear matter and neutron matter are calculated in the Walecka model with a Boltzmann-Uehling-Uhlenbeck collision term by means of a Chapman-Enskog expansion in first order. The order of magnitude of the influence of collective effects induced by the presence of the mean σ and ω fields on these coefficients is evaluated. (orig.). 9 figs
Proton impurity in the neutron matter: a nuclear polaron problem
Energy Technology Data Exchange (ETDEWEB)
Kutschera, M [Institute of Nuclear Physics, Cracow (Poland); Wojcik, W [Politechnika Krakowska, Cracow (Poland)
1992-10-01
We study interactions of a proton impurity with density oscillations of the neutron matter in a Debye approximation. The proton-phonon coupling is of the deformation-potential type at long wavelengths. It is weak at low density and increases with the neutron matter density. We calculate the proton`s effective mass perturbatively for a weak coupling, and use a canonical transformation technique for stronger couplings. The proton`s effective mass grows significantly with density, and at higher densities the proton impurity can be localized. This behaviour is similar to that of the polaron in solids. We obtain properties of the localized proton in the strong coupling regime from variational calculations, treating the neutron in the Thomas-Fermi approximation. (author). 14 refs, 8 figs.
Tensor quasiparticle interaction and spin-isospin sound in nuclear matter
International Nuclear Information System (INIS)
Haensel, P.
1979-01-01
The effect of the tensor components of the quasiparticle interaction in nuclear matter on the spin-isospin sound type excitations is studied. Numerical results are obtained using a simplified model of the quasiparticle interaction in nuclear matter. The quasiparticle distribution matrix corresponding to the spin-isospin sound is found to be qualitatively different from that obtained for purely central quasiparticle interaction. The macroscopic effects, however, are restricted to a small change in the phase velocity of the spin-isospin sound. (Auth.)
Nuclear matter properties using different sets of parameters in the Gogny interaction
International Nuclear Information System (INIS)
Ramadan, Kh.A.; Mansour, H.M.M.
2002-01-01
In the present work we use the finite range density dependent effective Gogny interaction to study the equation of state of polarized nuclear matter. Six sets of the interaction parameters are used and a comparison is made with the calculations of Friedman and Pandharipande using a realistic interaction. One of the parameter sets (D1) gives similar results for the properties of polarized nuclear matter while the other parameter sets (D1S, D250, D260, D280 and D300) yield results which are reasonably comparable with the realistic interaction calculation of Friedman and Pandharipande. (author)
The stability of nuclear matter in the Nambu-Jona-Lasinio model
Energy Technology Data Exchange (ETDEWEB)
Bentz, W. E-mail: bentz@keyaki.cc.u-tokai.ac.jp; Thomas, A.W. E-mail: athomas@physics.adelaide.edu.au
2001-12-17
Using the Nambu-Jona-Lasinio model to describe the nucleon as a quark-diquark state, we discuss the stability of nuclear matter in a hybrid model for the ground state at finite nucleon density. It is shown that a simple extension of the model to simulate the effects of confinement leads to a scalar polarizability of the nucleon. This, in turn, leads to a less attractive effective interaction between the nucleons, helping to achieve saturation of the nuclear matter ground state. It is also pointed out that that the same effect naturally leads to a suppression of 'Z-graph' contributions with increasing scalar potential.
Radiative muon capture and induced pseudoscalar coupling constant in nuclear matter
International Nuclear Information System (INIS)
Cheoun, Myung Ki; Kim, K S; Choi, T K
2003-01-01
Radiative muon capture is studied to investigate the induced pseudoscalar coupling constant g P in nuclear matter. According to the recent TRIUMF experiment for μ - p → nν μ γ, the g P was surprisingly larger than the value obtained from μ - p → nν μ experiment by as much as 44%. The result may affect seriously theoretical interpretations of the experimental results for the radiative muon captures in finite nuclei. In view of the recent TRIUMF result, the radiative muon capture in nuclear matter is revisited in a framework of the relativistic mean field theory
Nuclear matter with a pseudo-particle model: static bulk and surface properties
International Nuclear Information System (INIS)
Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.
1993-01-01
Direct calculations of cold and hot nuclear matter (bulk and surface properties) are carried out within the frame of a pseudo-particle model using a gaussian decomposition of the distribution function. Comparisons with Hartree-Fock calculations, for a large class of effective interactions, show that such a model is reliable to reproduce accurately the equation of state of nuclear matter for large ranges of densities and temperatures. The number of gaussians per nucleon and the gaussian widths are critical parameters in that semi-classical model. (orig.)
Nuclear matter with pseudo-particle model: static bulk and surface properties
Energy Technology Data Exchange (ETDEWEB)
Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.
1993-12-31
Direct calculations of cold and hot nuclear matter (bulk and surface properties) are carried out within the frame of a pseudo-particle model using a Gaussian decomposition of the distribution function. Comparisons with Hartree-Fock calculations, for a large class of effective interactions, show that such a model is reliable to reproduce accurately the equation of state of nuclear matter for large ranges of densities and temperatures. The number of Gaussian per nucleon and the Gaussian widths are critical parameters in that semi-classical model. (author) 13 refs.; 9 figs.; 2 tabs.
Nuclear matter with pseudo-particle model: static bulk and surface properties
International Nuclear Information System (INIS)
Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.
1993-01-01
Direct calculations of cold and hot nuclear matter (bulk and surface properties) are carried out within the frame of a pseudo-particle model using a Gaussian decomposition of the distribution function. Comparisons with Hartree-Fock calculations, for a large class of effective interactions, show that such a model is reliable to reproduce accurately the equation of state of nuclear matter for large ranges of densities and temperatures. The number of Gaussian per nucleon and the Gaussian widths are critical parameters in that semi-classical model. (author) 13 refs.; 9 figs.; 2 tabs
Nuclear matter with a pseudo-particle model: static bulk and surface properties
Energy Technology Data Exchange (ETDEWEB)
Idier, D. (Lab. de Physique Nucleaire CNRS/IN2P3, Univ. de Nantes (France)); Benhassine, B. (Lab. de Physique Nucleaire CNRS/IN2P3, Univ. de Nantes (France)); Farine, M. (Lab. de Physique Nucleaire CNRS/IN2P3, Univ. de Nantes (France)); Remaud, B. (Lab. de Physique Nucleaire CNRS/IN2P3, Univ. de Nantes (France)); Sebille, F. (Lab. de Physique Nucleaire CNRS/IN2P3, Univ. de Nantes (France))
1993-11-15
Direct calculations of cold and hot nuclear matter (bulk and surface properties) are carried out within the frame of a pseudo-particle model using a gaussian decomposition of the distribution function. Comparisons with Hartree-Fock calculations, for a large class of effective interactions, show that such a model is reliable to reproduce accurately the equation of state of nuclear matter for large ranges of densities and temperatures. The number of gaussians per nucleon and the gaussian widths are critical parameters in that semi-classical model. (orig.)
Equation of state and stability of hot asymmetric nuclear matter
International Nuclear Information System (INIS)
Samaddar, S.K.
1989-01-01
The nuclear incompressibility as obtained from different sources, from nuclei, high energy nuclear collisions, supernova and neutron stars are briefly reviewed. All these data in general favour a compression modulus, K α ∼ 300 Mev with a minimum uncertainty ∼ 50 MeV. Using a finite rang e density and momentum dependent two-body effective interaction, variation of nucl ear incompressibility with temperature, asymmetry and density is discussed in a non-relativistic mean field approach. The same formalism has also been used to study the limiting temperatures of infinite as well as finite nuclear systems in the astrophysical context as well as in high energy heavy ion collisions. (autho r). 16 refs., 6 figs., 1 tab
Hyperons in nuclear matter from SU(3) chiral effective field theory
Energy Technology Data Exchange (ETDEWEB)
Petschauer, Stefan; Kaiser, Norbert [Technische Universitaet Muenchen (Germany); Haidenbauer, Johann [Forschungszentrum Juelich (Germany); Meissner, Ulf G. [Forschungszentrum Juelich (Germany); Universitaet Bonn (Germany); Weise, Wolfram [Technische Universitaet Muenchen (Germany); ECT, Trento (Italy)
2016-07-01
Brueckner theory is used to investigate the properties of hyperons in nuclear matter. The hyperon-nucleon interaction is taken from chiral effective field theory at next-to-leading order with SU(3) symmetric low-energy constants. Furthermore, the underlying nucleon-nucleon interaction is also derived within chiral effective field theory. We present the single-particle potentials of Λ and Σ hyperons in symmetric and asymmetric nuclear matter computed with the continuous choice for intermediate spectra. The results are in good agreement with the empirical information. In particular, our calculation gives a repulsive Σ-nuclear potential and a weak Λ-nuclear spin-orbit force. The splittings among the Σ{sup +}, Σ{sup 0} and Σ{sup -} potentials have a non-linear dependence on the isospin asymmetry which goes beyond the usual parametrization in terms of an isovector Lane potential.
Relativistic and non-relativistic studies of nuclear matter
Banerjee, MK; Tjon, JA
2002-01-01
We point out that the differences between the results of the non-relativistic lowest order Brueckner theory (LOBT) and the relativistic Dirac-Brueckner analysis predominantly arise from two sources. Besides effects from a nucleon mass modification M* in nuclear medium we have in a relativistic
Pinning down nuclear. To the core of the matter
International Nuclear Information System (INIS)
Boeck, Helmut; Gerstmayr, Michael; Radde, Eileen
2014-01-01
The nuclear disaster in Fukushima shocked the world tremendously. The call to pull out of nuclear energy is getting louder - and more often than not by politicians trying to lure the favour of voters. Through the media there are half-truths and false information floating about the global consequences of the disaster and sensational prognoses for the future, all of which are in turn unsettling for the general public. Are the opposers to nuclear energy playing with the fear of the public or is the threat real? This book tells, in a captivating manner - authenticated with examples and incidents not known by many - what the threat for the area actually looks like. They confront the level of truth in the frightening scenarios and inform about the situation in case of emergency. Furthermore, they examine factors that preceded the disaster and broach the subject of the incredible hunger for energy, which dominates the world and continues to drive the commercial use of nuclear energy. Also the ghost of Chernobyl and its aftermath, which has been dismissed from our minds, is re-examined based on current knowledge. The book impresses with insider know-how, latest detailed knowledge, amazing facts and an entertaining narrative style.
Fluctuation effects on bubble growth in hot nuclear matter
International Nuclear Information System (INIS)
Santiago, A.J.; Chung, K.C.
1991-01-01
The evolution of bubbles with arbitrary density in an infinite nuclear system is studied in a simplified treatment. Kinetic pressure fluctuations on the bubble surface are considered. The critical radius, evolution time and probability for bubble expansion are shown to depend significantly on the initial bubble density. (author)
Pinning down nuclear. To the core of the matter
Energy Technology Data Exchange (ETDEWEB)
Boeck, Helmut; Gerstmayr, Michael [Technische Univ., Vienna (Austria); International Atomic Energy Agency, Vienna (Austria); Radde, Eileen [Nuclear Engineering Seibersdorf GmbH (Austria); International Atomic Energy Agency, Vienna (Austria)
2014-07-01
The nuclear disaster in Fukushima shocked the world tremendously. The call to pull out of nuclear energy is getting louder - and more often than not by politicians trying to lure the favour of voters. Through the media there are half-truths and false information floating about the global consequences of the disaster and sensational prognoses for the future, all of which are in turn unsettling for the general public. Are the opposers to nuclear energy playing with the fear of the public or is the threat real? This book tells, in a captivating manner - authenticated with examples and incidents not known by many - what the threat for the area actually looks like. They confront the level of truth in the frightening scenarios and inform about the situation in case of emergency. Furthermore, they examine factors that preceded the disaster and broach the subject of the incredible hunger for energy, which dominates the world and continues to drive the commercial use of nuclear energy. Also the ghost of Chernobyl and its aftermath, which has been dismissed from our minds, is re-examined based on current knowledge. The book impresses with insider know-how, latest detailed knowledge, amazing facts and an entertaining narrative style.
2012-02-24
... and NPF-69] In the Matter of Exelon Corporation; Constellation Energy Group, Inc.; Nine Mile Nuclear..., LLC (Exelon Ventures), and Constellation Energy Nuclear Group, LLC (CENG), acting on behalf of itself... Nuclear Advisory Committee of Constellation Energy Nuclear Group, LLC, shall prepare an Annual Report...
Isospin-dependent properties of asymmetric nuclear matter in relativistic mean-field models
Chen, Lie-Wen; Ko, Che Ming; Li, Bao-An
2007-01-01
Using various relativistic mean-field models, including the nonlinear ones with meson field self-interactions, those with density-dependent meson-nucleon couplings, and the point-coupling models without meson fields, we have studied the isospin-dependent bulk and single-particle properties of asymmetric nuclear matter. In particular, we have determined the density dependence of nuclear symmetry energy from these different relativistic mean-field models and compare the results with the constra...
Wigner-Kirkwood expansion of the phase-space density for half infinite nuclear matter
International Nuclear Information System (INIS)
Durand, M.; Schuck, P.
1987-01-01
The phase space distribution of half infinite nuclear matter is expanded in a ℎ-series analogous to the low temperature expansion of the Fermi function. Besides the usual Wigner-Kirkwood expansion, oscillatory terms are derived. In the case of a Woods-Saxon potential, a smallness parameter is defined, which determines the convergence of the series and explains the very rapid convergence of the Wigner-Kirkwood expansion for average (nuclear) binding energies
Halftime - a balance in matters nuclear of the grand coalition
International Nuclear Information System (INIS)
Heller, W.
2007-01-01
On November 11, 2005, the coalition partners, CDU/CSU and SPD, signed the agreement establishing a coalition in the German federal parliament under the heading of ''Together for Germany''. Among other things, this raised the question of what would happen in the fields of energy policy and nuclear power. After 2 years of a grand coalition, it is time to draw some interim conclusions. The coalition agreement contains statements to the effect that energy policy means fundamental economic, structural and climate policies, and that secure, low-cost, non-polluting energy supplies are elementary prerequisites of a modern, capable national economy. A sustainable overall energy policy concept should be based on a balanced energy mix. This overall concept, one of the results of ''energy summit'' talks with Federal Chancellor Merkel, was announced for the end of 2007. The 3 energy summit discussions with Federal Chancellor Merkel deliberately avoided the subject of nuclear power. There is no debate about the implications of nuclear energy. This in no way improved the status of nuclear power in Germany. What remains is hope for the second half of this government's term of office. The beginning of that term is marked by the McKinsey study, initiated by the Federation of German Industries (BDI), on ''Cost and Potential of Avoiding Greenhouse Gas Emissions in Germany,'' which says that operating German nuclear power plants for 60 or even 45 years would result in a CO2 avoidance potential for 2020 which would be approximately 90 million tons higher, and in avoidance costs lower by 4.5 billion euro per year. (orig.)
The 132Sn giant dipole resonance as a constraint on nuclear matter properties
Roach, Brandon; Bonasera, Giacomo; Shlomo, Shalom
2015-10-01
Nuclear giant resonances provide a sensitive method for constraining the properties of nuclear matter (NM) - many of which have large uncertainties - and thereby improve the nuclear energy-density functional. In this work, self-consistent Hartree-Fock random-phase approximation (HF-RPA) theory was employed to calculate the strength function and energy of the isovector giant dipole resonance (IVGDR) in the doubly-magic 132Sn nucleus. Several (17) commonly-used Skyrme-type interactions were employed. The correlations between the IVGDR centroid energy and each nuclear matter property were explored, as were correlations between the nuclear matter properties and the 132Sn neutron skin thickness rn -rp . Experimental data for the IVGDR centroid energy was used to constrain the symmetry energy density, the symmetry energy, and its first and second derivatives, respectively, of NM. Further investigation, particularly of nuclides far from stability, will be needed to extend the nuclear energy-density functional to the extremes of density and neutron abundance found in neutron stars and astrophysical nucleosynthesis environments.
ERK5 and cell proliferation: nuclear localization is what matters
Directory of Open Access Journals (Sweden)
Nestor Gomez
2016-09-01
Full Text Available ERK5, the last MAP kinase family member discovered, is activated by the upstream kinase MEK5 in response to growth factors and stress stimulation. MEK5-ERK5 pathway has been associated to different cellular processes, playing a crucial role in cell proliferation in normal and cancer cells by mechanisms that are both dependent and independent of its kinase activity. Thus, nuclear ERK5 activates transcription factors by either direct phosphorylation or acting as co-activator thanks to a unique transcriptional activation TAD domain located at its C-terminal tail. Consequently, ERK5 has been proposed as an interesting target to tackle different cancers, and either inhibitors of ERK5 activity or silencing the protein have shown antiproliferative activity in cancer cells and to block tumour growth in animal models. Here, we review the different mechanisms involved in ERK5 nuclear translocation and their consequences. Inactive ERK5 resides in the cytosol, forming a complex with Hsp90-Cdc37 superchaperone. In a canonical mechanism, MEK5-dependent activation results in ERK5 C-terminal autophosphorylation, Hsp90 dissociation and nuclear translocation. This mechanism integrates signals such as growth factors and stresses that activate the MEK5-ERK5 pathway. Importantly, two other mechanisms, MEK5-independent, have been recently described. These mechanisms allow nuclear shuttling of kinase-inactive forms of ERK5. Although lacking kinase activity, these forms activate transcription by interacting with transcription factors through the TAD domain. Both mechanisms also require Hsp90 dissociation previous to nuclear translocation. One mechanism involves phosphorylation of the C-terminal tail of ERK5 by kinases that are activated during mitosis, such as Cyclin-dependent kinase-1. The second mechanism involves overexpression of chaperone Cdc37, an oncogene that is overexpressed in cancers such as prostate adenocarcinoma, where it collaborates with ERK5 to promote
Theory of dressed bosons and nuclear matter distributions
International Nuclear Information System (INIS)
Tomaselli, M.; Liu, L.C.; Tanihata, I.
2002-09-01
The structure of nuclei with large neutron or proton-neutron excess, i.e., with large isospin components, is investigated in the Boson Dynamic Correlation Model where the valence particle pairs are dressed by their interactions with the microscopic clusters of the core. The mixed-mode states of the model are the eigenstates of a set of nonlinear equations. We solve these equations in terms of the cluster factorizations that are introduced to compute the n-boson matrix elements. Our calculation of the energy levels of 18 O reveals a strong mixing between the valence and core clusters which leads to a large reduction of the spectroscopic factors as calculated in Shell-Model approximations. The coupling of valence- to core-clusters gives a new insight into the halo formation in neutron-rich nuclei, namely, the halo is also a consequence of the excitation of the core protons. The calculated matter distributions of 6 He and 6 Li exhibit strong similarities, which indicate that halo formation in nuclei with proton-neutron excess must be postulated. The matter distributions of these two isotopes reproduce well the differential cross sections obtained in the proton elastic scattering experiments performed at GSI in inverse kinematics at an energy of 0.7 GeV/u. (orig.)
Historical trend of nuclear matter calculation and its recent developments
International Nuclear Information System (INIS)
Kohno, Michio
2006-01-01
He guide line to understand nuclear properties on the basis of nuclear force was started in the 1950's by the Brueckner theory. The theory established the fundamental framework to formulate the picture to consider both the two nucleon and tensor correlations as well as Pauli effect inside the nuclei. In the 1960's the theory was developed to obtain ground state energy on the perturbation many-body theory. The growth and refinement of the Brueckner theory in the 1970's and after are overviewed and the computer code developments in the 1980's are mentioned. Concerning the many-body correlation problem Italian group has calculated up to three-body correlations in the Brueckner theory. At present, effective interaction nuclear theory is coming into a new level and actively studied by the introduction of low momentum interaction based on the renormalization group theory, by full application of the coupled cluster method, by the application of Skyrme Hartree-Fock method in wide range and by the reconsideration of the energy density functional method in relation to the relativistic mean field method. Owing to the recent remarkable progress of computers, calculations which were impossible to be executed in old days are now done rather easily. (S. Funahashi)
Besson, Ugo; De Ambrosis, Anna; Mascheretti, Paolo
2010-01-01
We present a teaching module dealing with the thermal effects of interaction between radiation and matter, the infrared emission of bodies and the greenhouse effect devoted to university level and teacher education. The module stresses the dependence of the optical properties of materials (transparency, absorptivity and emissivity) on radiation…
Which role for nuclear power in the battle against global warming?
International Nuclear Information System (INIS)
Jean-Baptiste, Ph.; Ducroux, R.
2000-01-01
The climatic impact of massive releases of carbon dioxide from the burning of fossil fuels has become a major international issue. Atmospheric CO 2 concentration continually increases. At the present rate, it is predicted that by 2040 it will have doubled with respect to its pre-industrial level. In a growing world economy, now dependent on fossil fuels for 90% of its energy, only a drastic change in energy policy involving extensive use of CO 2 -free energies can make it possible to stabilize atmospheric CO 2 levels. With 35 % of its primary energy from nuclear reactors, France sets a good example for the greenhouse gas reduction. Using this energy has resulted in a 20% reduction in releases since 1973. During the same period, world emissions have increased by 45%. In view of the French experience in 25 years of managing a large number of nuclear reactors in respecting safety requirements and environmental impact, it appears that nuclear energy has an important role to play in the battle against greenhouse gases. (authors)
International Nuclear Information System (INIS)
Ru-Keng Su; Li Li; Hong-Qiu Song
1998-01-01
The effects of the tensor coupling term on nuclear matter in the Zimanyi-Moszkowki (ZM) model are investigated. It is shown that the tensor coupling term in the ZM model leaves the thermodynamical properties of nuclear matter almost unchanged. The corrections of tensor coupling to the critical point of the liquid-gas phase transition are given. (author)
Self-consistent green function calculations for isospin asymmetric nuclear matter
International Nuclear Information System (INIS)
Mansour, Hesham; Gad, Khalaf; Hassaneen, Khaled S.A.
2010-01-01
The one-body potentials for protons and neutrons are obtained from the self-consistent Green-function calculations of asymmetric nuclear matter, in particular their dependence on the degree of proton/neutron asymmetry. Results of the binding energy per nucleon as a function of the density and asymmetry parameter are presented for the self-consistent Green function approach using the CD-Bonn potential. For the sake of comparison, the same calculations are performed using the Brueckner-Hartree-Fock approximation. The contribution of the hole-hole terms leads to a repulsive contribution to the energy per nucleon which increases with the nuclear density. The incompressibility for asymmetric nuclear matter has been also investigated in the framework of the self-consistent Green-function approach using the CD-Bonn potential. The behavior of the incompressibility is studied for different values of the nuclear density and the neutron excess parameter. The nuclear symmetry potential at fixed nuclear density is also calculated and its value decreases with increasing the nucleon energy. In particular, the nuclear symmetry potential at saturation density changes from positive to negative values at nucleon kinetic energy of about 200 MeV. For the sake of comparison, the same calculations are performed using the Brueckner-Hartree-Fock approximation. The proton/neutron effective mass splitting in neutron-rich matter has been studied. The predicted isospin splitting of the proton/neutron effective mass splitting in neutron-rich matter is such that m n * ≥ m p * . (author)
Computational methods for the nuclear and neutron matter problems. Progress report
International Nuclear Information System (INIS)
Kalos, M.H.
1979-01-01
A brief report is given of progress on the development of Monte Carlo methods for the treatment of both simplified and realistic models of extensive neutron and nuclear matter and, eventually, of finite nuclei. A wide class of algorithms that may allow the efficient sampling of the integrands required in calculating the energy expectations with useful trial wave functions was devised
Single Particle Potential of a Σ Hyperon in Nuclear Matter. II Rearrangement Effects
International Nuclear Information System (INIS)
Dabrowski, J.
2000-01-01
The rearrangement contribution to the real part of the single particle potential of a Σ hyperon in nuclear matter, U Σ , is investigated. The isospin and spin dependent parts of U Σ are considered. Results obtained for four models of the Nijmegen baryon-baryon interaction are presented and discussed. (author)
Extension of Hartree-Fock theory including tensor correlation in nuclear matter
Hu, Jinniu; Toki, Hiroshi; Ogawa, Yoko
2013-10-01
We study the properties of nuclear matter in the extension of Hartree-Fock theory including tensor correlation using a realistic nucleon-nucleon (NN) interaction. The nuclear wave function consists of the Hartree-Fock and two-particle-two-hole (2p-2h) states, following the concept of the tensor-optimized shell model (TOSM) for light nuclei. The short range repulsion and strong tensor force of realistic NN interaction provide high momentum components, which are taken into account in a many-body framework by introducing 2p-2h states. Single particle states are determined by the variational principle of the total energy with respect to 2p-2h amplitudes and Hartree-Fock (HF) single-particle states. The resulting differential equation is almost identical with that of Brueckner-Hartree-Fock (BHF) theory by taking two-body scattering terms only. We calculate the equation of state (EOS) of nuclear matter in this framework with the Bonn potential as a realistic NN interaction. We found similar results to BHF theory with slightly repulsive effects in the total energy. The relativistic effect is discussed for the EOSs of nuclear matter in both non-relativistic and relativistic frameworks. The momentum distribution has large components at high momenta due to 2p-2h excitations. We also obtain the EOSs of pure neutron matter, where the tensor effect is small in the iso-vector channel.
Evidences for a new state of the nuclear matter: quark gluon plasma in liquid phase
International Nuclear Information System (INIS)
Jipa, Alexandru
2005-01-01
The experimental results obtained in the last years at the RHIC BNL (USA) allowed to obtain an important experimental result, namely the observation of the quark gluon plasma formation in nucleus-nucleus collisions at 200 A GeV in CMS. Evidences for this new state of nuclear matter are presented in this work. The results of the BRAHMS Experiment are detailed. (author)
Time scales for spinodal decomposition in nuclear matter with pseudo-particle model
Energy Technology Data Exchange (ETDEWEB)
Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.
1993-12-31
Dynamical instabilities arising from fluctuations in the spinodal zone for nuclear matter are studied using a large variety of zero range interactions in the frame of a pseudo-particle model. Scale times for spinodal decomposition are extracted and a possible link with decomposition in real heavy-ion collisions is discussed. (author) 12 refs.; 6 figs.; 1 tab.
Time scales for spinodal decomposition in nuclear matter with pseudo-particle model
International Nuclear Information System (INIS)
Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.
1993-01-01
Dynamical instabilities arising from fluctuations in the spinodal zone for nuclear matter are studied using a large variety of zero range interactions in the frame of a pseudo-particle model. Scale times for spinodal decomposition are extracted and a possible link with decomposition in real heavy-ion collisions is discussed. (author) 12 refs.; 6 figs.; 1 tab
Time scales for spinodal decomposition in nuclear matter with pseudoparticle models
International Nuclear Information System (INIS)
Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F.
1993-01-01
Dynamical instabilities arising from fluctuations in the spinodal zone for nuclear matter are studied using a large variety of zero range interactions in the frame of a pseudoparticle model. Scale times for spinodal decomposition are extracted and a possible link with decomposition in real heavy-ion collisions is discussed
Time scales for spinodal decomposition in nuclear matter with pseudoparticle models
Energy Technology Data Exchange (ETDEWEB)
Idier, D.; Benhassine, B.; Farine, M.; Remaud, B.; Sebille, F. (Laboratoire de Physique Nucleaire CNRS/IN2P3, Universite de Nantes, 2, rue de la Houssiniere, 44072 Nantes (France))
1993-08-01
Dynamical instabilities arising from fluctuations in the spinodal zone for nuclear matter are studied using a large variety of zero range interactions in the frame of a pseudoparticle model. Scale times for spinodal decomposition are extracted and a possible link with decomposition in real heavy-ion collisions is discussed.
Nuclear recoil energy scale in liquid xenon with application to the direct detection of dark matter
International Nuclear Information System (INIS)
Sorensen, Peter; Dahl, Carl Eric
2011-01-01
We show for the first time that the quenching of electronic excitation from nuclear recoils in liquid xenon is well-described by Lindhard theory, if the nuclear recoil energy is reconstructed using the combined (scintillation and ionization) energy scale proposed by Shutt et al. We argue for the adoption of this perspective in favor of the existing preference for reconstructing nuclear recoil energy solely from primary scintillation. We show that signal partitioning into scintillation and ionization is well described by the Thomas-Imel box model. We discuss the implications for liquid xenon detectors aimed at the direct detection of dark matter.
QCD evolution equations for high energy partons in nuclear matter
Kinder-Geiger, Klaus; Geiger, Klaus; Mueller, Berndt
1994-01-01
We derive a generalized form of Altarelli-Parisi equations to decribe the time evolution of parton distributions in a nuclear medium. In the framework of the leading logarithmic approximation, we obtain a set of coupled integro- differential equations for the parton distribution functions and equations for the virtuality (``age'') distribution of partons. In addition to parton branching processes, we take into account fusion and scattering processes that are specific to QCD in medium. Detailed balance between gain and loss terms in the resulting evolution equations correctly accounts for both real and virtual contributions which yields a natural cancellation of infrared divergences.
Nuclear matter at high density: Phase transitions, multiquark states, and supernova outbursts
International Nuclear Information System (INIS)
Krivoruchenko, M. I.; Nadyozhin, D. K.; Rasinkova, T. L.; Simonov, Yu. A.; Trusov, M. A.; Yudin, A. V.
2011-01-01
Phase transition from hadronic matter to quark-gluon matter is discussed for various regimes of temperature and baryon number density. For small and medium densities, the phase transition is accurately described in the framework of the Field Correlation Method, whereas at high density predictions are less certain and leave room for the phenomenological models. We study formation of multiquark states (MQS) at zero temperature and high density. Relevant MQS components of the nuclear matter can be described using a previously developed formalism of the quark compound bags (QCB). Partialwave analysis of nucleon-nucleon scattering indicates the existence of 6QS which manifest themselves as poles of P matrix. In the framework of the QCB model, we formulate a self-consistent system of coupled equations for the nucleon and 6QS propagators in nuclear matter and the G matrix. The approach provides a link between high-density nuclear matter with the MQS components and the cumulative effect observed in reactions on the nuclei, which requires the admixture of MQS in the wave functions of nuclei kinematically. 6QS determines the natural scale of the density for a possible phase transition into theMQS phase of nuclear matter. Such a phase transition can lead to dynamic instability of newly born protoneutron stars and dramatically affect the dynamics of supernovae. Numerical simulations show that the phase transition may be a good remedy for the triggering supernova explosions in the spherically symmetric supernovamodels. A specific signature of the phase transition is an additional neutrino peak in the neutrino light curve. For a Galactic core-collapse supernova, such a peak could be resolved by the present neutrino detectors. The possibility of extracting the parameters of the phase of transition from observation of the neutrino signal is discussed also.
Nuclear matter at high density: Phase transitions, multiquark states, and supernova outbursts
Energy Technology Data Exchange (ETDEWEB)
Krivoruchenko, M. I.; Nadyozhin, D. K.; Rasinkova, T. L.; Simonov, Yu. A.; Trusov, M. A., E-mail: trusov@itep.ru; Yudin, A. V. [Institute for Theoretical and Experimental Physics (Russian Federation)
2011-03-15
Phase transition from hadronic matter to quark-gluon matter is discussed for various regimes of temperature and baryon number density. For small and medium densities, the phase transition is accurately described in the framework of the Field Correlation Method, whereas at high density predictions are less certain and leave room for the phenomenological models. We study formation of multiquark states (MQS) at zero temperature and high density. Relevant MQS components of the nuclear matter can be described using a previously developed formalism of the quark compound bags (QCB). Partialwave analysis of nucleon-nucleon scattering indicates the existence of 6QS which manifest themselves as poles of P matrix. In the framework of the QCB model, we formulate a self-consistent system of coupled equations for the nucleon and 6QS propagators in nuclear matter and the G matrix. The approach provides a link between high-density nuclear matter with the MQS components and the cumulative effect observed in reactions on the nuclei, which requires the admixture of MQS in the wave functions of nuclei kinematically. 6QS determines the natural scale of the density for a possible phase transition into theMQS phase of nuclear matter. Such a phase transition can lead to dynamic instability of newly born protoneutron stars and dramatically affect the dynamics of supernovae. Numerical simulations show that the phase transition may be a good remedy for the triggering supernova explosions in the spherically symmetric supernovamodels. A specific signature of the phase transition is an additional neutrino peak in the neutrino light curve. For a Galactic core-collapse supernova, such a peak could be resolved by the present neutrino detectors. The possibility of extracting the parameters of the phase of transition from observation of the neutrino signal is discussed also.
Nuclear ``pasta'' structures in low-density nuclear matter and properties of the neutron-star crust
Okamoto, Minoru; Maruyama, Toshiki; Yabana, Kazuhiro; Tatsumi, Toshitaka
2013-08-01
In the neutron-star crust, nonuniform structure of nuclear matter—called the “pasta” structure—is expected. From recent studies of giant flares in magnetars, these structures might be related to some observables and physical quantities of the neutron-star crust. To investigate the above quantities, we numerically explore the pasta structure with a fully three-dimensional geometry and study the properties of low-density nuclear matter, based on the relativistic mean-field model and the Thomas-Fermi approximation. We observe typical pasta structures for fixed proton number fraction and two of them for cold catalyzed matter. We also discuss the crystalline configuration of “pasta.”
Equation of state of asymmetric nuclear matter using re-projected nucleon–nucleon potentials
Asadi Aghbolaghi, Z.; Bigdeli, M.
2018-06-01
In this paper, we have calculated the equation of state of asymmetric nuclear matter using the lowest order constrained variational approach and Argonne family potentials with and without three-nucleon interaction (TNI) contribution. In particular, we have used the AV18 potential and the re-projected potentials, AV8‧, and AV6‧. We have also calculated the saturation properties of symmetric nuclear matter, and the nuclear symmetry energy using AV18+TNI, AV8‧+TNI and AV6‧+TNI potentials. The inclusion of TNI has modified the agreement with experiment. We have also made a comparison between our results and those of other many-body calculations.
Cold Nuclear Matter Effects on J/psi Production: Intrinsic and Extrinsic Transverse Momentum Effects
Energy Technology Data Exchange (ETDEWEB)
Ferreiro, E.G.; /Santiago de Compostela U.; Fleuret, F.; /Ecole Polytechnique; Lansberg, J.P.; /Heidelberg U.; Rakotozafindrabe, A.; /SPhN, DAPNIA, Saclay
2010-08-26
Cold nuclear matter effects on J/{psi} production in proton-nucleus and nucleus-nucleus collisions are evaluated taking into account the specific J/{psi}-production kinematics at the partonic level, the shadowing of the initial parton distributions and the absorption in the nuclear matter. We consider two different parton processes for the c{bar c}-pair production: one with collinear gluons and a recoiling gluon in the final state and the other with initial gluons carrying intrinsic transverse momentum. Our results are compared to RHIC observables. The smaller values of the nuclear modification factor R{sub AA} in the forward rapidity region (with respect to the mid rapidity region) are partially explained, therefore potentially reducing the need for recombination effects.
Hadron structure in a simple model of quark/nuclear matter
International Nuclear Information System (INIS)
Horowitz, C.J.; Moniz, E.J.; Negele, J.W.
1985-01-01
We study a simple model for one-dimensional hadron matter with many of the essential features needed for examining the transition from nuclear to quark matter and the limitations of models based upon hadron rather than quark degrees of freedom. The dynamics are generated entirely by the quark confining force and exchange symmetry. Using Monte Carlo techniques, the ground-state energy, single-quark momentum distribution, and quark correlation function are calculated for uniform matter as a function of density. The quark confinement scale in the medium increases substantially with increasing density. This change is evident in the correlation function and momentum distribution, in qualitative agreement with the changes observed in deep-inelastic lepton scattering. Nevertheless, the ground-state energy is smooth throughout the transition to quark matter and is described remarkably well by an effective hadron theory based on a phenomenological hadron-hadron potential
Intrinsic neutron background of nuclear emulsions for directional Dark Matter searches
Alexandrov, A.; Asada, T.; Buonaura, A.; Consiglio, L.; D'Ambrosio, N.; De Lellis, G.; Di Crescenzo, A.; Di Marco, N.; Di Vacri, M. L.; Furuya, S.; Galati, G.; Gentile, V.; Katsuragawa, T.; Laubenstein, M.; Lauria, A.; Loverre, P. F.; Machii, S.; Monacelli, P.; Montesi, M. C.; Naka, T.; Pupilli, F.; Rosa, G.; Sato, O.; Strolin, P.; Tioukov, V.; Umemoto, A.; Yoshimoto, M.
2016-07-01
Recent developments of the nuclear emulsion technology led to the production of films with nanometric silver halide grains suitable to track low energy nuclear recoils with submicrometric length. This improvement opens the way to a directional Dark Matter detection, thus providing an innovative and complementary approach to the on-going WIMP searches. An important background source for these searches is represented by neutron-induced nuclear recoils that can mimic the WIMP signal. In this paper we provide an estimation of the contribution to this background from the intrinsic radioactive contamination of nuclear emulsions. We also report the neutron-induced background as a function of the read-out threshold, by using a GEANT4 simulation of the nuclear emulsion, showing that it amounts to about 0.06 per year per kilogram, fully compatible with the design of a 10 kg × year exposure.
Hyperon interaction in free space and nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Dhar, Madhumita [Justus-Liebig University Giessen (Germany); Lenske, Horst [Justus-Liebig University Giessen (Germany); GSI, Darmstadt (Germany)
2016-07-01
A new approach to the SU(3) flavour symmetric meson-exchange model is introduced to describe free space baryon-baryon interaction. The Bethe-Salpeter equations are solved in a 3-D reduction scheme. The coupling of the various channels of total strangeness S and conserved total charge Q is studied in detail. Special attention is paid to the physical thresholds. The derived vacuum interaction has then been used to derive nuclear medium effect by employing the Pauli projector operator in 3-D reduced Bethe-Salpeter equation. The in-medium properties of the interaction are clearly seen in the variation of the in-medium low-energy parameters as a function of density.
SIGNATURES OF DARK MATTER BURNING IN NUCLEAR STAR CLUSTERS
International Nuclear Information System (INIS)
Casanellas, Jordi; Lopes, IlIdio
2011-01-01
In order to characterize how dark matter (DM) annihilation inside stars changes the aspect of a stellar cluster, we computed the evolution until the ignition of the He burning of stars from 0.7 M sun to 3.5 M sun within halos of DM with different characteristics. We found that, when a cluster is surrounded by a dense DM halo, the positions of the cluster' stars in the H-R diagram have a brighter and hotter turnoff point than in the classical scenario without DM, therefore giving the cluster a younger appearance. The high DM densities required to produce these effects are expected only in very specific locations, such as near the center of our Galaxy. In particular, if DM is formed by the 8 GeV weakly interacting massive particles recently invoked to reconcile the results from direct detection experiments, then this signature is predicted for halos of DM with a density ρ χ = 3 x 10 5 GeV cm -3 . A DM density gradient inside the stellar cluster would result in a broader main sequence, turnoff, and red giant branch regions. Moreover, we found that for very high DM halo densities the bottom of the isochrones in the H-R diagram rises to higher luminosities, leading to a characteristic signature on the stellar cluster. We argue that this signature could be used to indirectly probe the presence of DM particles in the location of a cluster.
Determination of the equation of state of asymmetric nuclear matter
Energy Technology Data Exchange (ETDEWEB)
Tsang, Manyee Betty [Michigan State Univ., East Lansing, MI (United States)
2016-12-30
A new Time Projection Chamber (TPC), called the SπRIT (SAMURAI pion Reconstruction Ion Tracker) TPC was constructed and used successfully in two experiments with the SAMURAI spectrometer at RIKEN, Japan to study the equation of state of neutron rich matter. As a result of the project, the SπRIT collaboration, an international collaboration consisting of groups from US, Japan, Korea, Poland, China and Germany, has been formed to pursue the science opportunities provided by the SπRIT TPC. After completion of the TPC and the two experiments, the collaboration continues to develop the software to analyze the SπRIT experiments and extract constraints of symmetry energy at supra-saturation densities. Over 250 TB of data have been obtained in the last SπRIT TPC experimental campaign. Construction of the TPC provided opportunities for the scientists to develop new designs for the light-weight and thin-walled field cage for the large pad plane and for the gating grid. Two PhD students (1 US and 1 Korea) graduated in 2016 based on their research on the TPC. At least four more doctoral theses (2 US, 1 Japan and 1 Korea) based on physics from the SπRIT experiments are expected.
Leksin, G A
2002-01-01
Features of deep inelastic nuclear reactions proceeding on dense fluctuations of nuclear matter (fluctons) are briefly considered. Fluctons, which can be many-quark bags or drops of quark-gluon plasma, are studied. Their properties are discussed, viz., characteristic parameters of nuclear matter inside a flucton - temperature and density close to the critical values for a phase transition. These values can be reached or exceeded if the flucton-flucton collision events are separated. The separation method is discussed
Particle production in hot and dense nuclear matter
International Nuclear Information System (INIS)
Eklund, A.
1992-08-01
The charged particle production in heavy ion reactions at 200 A GeV has been studied for projectiles of 16 O and 32 S on targets of Al, Cu, Ag and Au. Up to 700 charged particles are measured in the pseudorapidity region -1.7 32 S+Au. The measured particle density is used to estimate the energy density attained in central collisions and gives a values of ≅2 GeV/fm 3 . This is close to the energy density predicted for the phase transition from hadronic matter to a quark-gluon plasma. To measure the large number of charged particle produced, finely granulated detector systems are employed. Streamer tube detectors with pad readout and large area, multi-step avalanche chambers with optical readout have been developed for the measurements. The widths of the pseudorapidity distributions of charged particles increase with decreasing centrality of the collision as well as with increasing mass of the target nucleus. This behaviour is assumed to be due to the target fragmentation. The Monte-Carlo model for nucleus-nucleus collisions, VENUS 3.11, which includes rescattering, is in reasonable agreement with the data. The yield of charged particles for central collisions of the heavy targets with 33 S is found to be proportional to the target mass, A, at target rapidity. At midrapidity it is approximately proportional to A 0.3 . At midrapidity the charged particle measurements are supplemented by measurements of the transverse energy. The dimensionless, normalized variances of the multiplicity and transverse energy distributions are, to a large extent, governed by the collision geometry. The change in the normalized variance when studying the charged particle distribution in a narrow angular region is explained as being of statistical nature. (au)
Neutron optical potentials in unstable nuclei and the equation of state of asymmetric nuclear matter
International Nuclear Information System (INIS)
Oyamatsu, K.; Iida, K.
2003-01-01
Neutron single particle potential is one of the basic macroscopic properties to describe structure and reactions of nuclei in nuclear reactors and in the universe. However, the potential is quite uncertain for unstable nuclei primarily because the equation of state (EOS) of asymmetric nuclear matter is not known well. The present authors studied systematically the empirical EOS of asymmetric nuclear matter using a macroscopic nuclear model; about two hundred EOS's having empirically allowed values of L (symmetry energy density derivative coefficient) and K 0 (incompressibility) were obtained from the fittings to masses and radii of stable nuclei. It was suggested that the L value could be determined from global (Z, A) dependence of nuclear radii. In the present study, the single particle potential is examined assuming kinetic energies of non-interacting Fermi gases. The potential in a nucleus can be calculated easily, once the density distribution is solved using the effective nuclear interaction (EOS). Neutron and proton single particle potentials are calculated systematically for 80 Ni using the two hundred EOS's. It is found that the neutron-proton potential difference has clear and appreciable L dependence, while the potential for each species does not show such simple dependence on L. (author)
Nuclear-Recoil Energy Scale in CDMS II Silicon Dark-Matter Detectors
Energy Technology Data Exchange (ETDEWEB)
Agnese, R.; et al.
2018-03-07
The Cryogenic Dark Matter Search (CDMS II) experiment aims to detect dark matter particles that elastically scatter from nuclei in semiconductor detectors. The resulting nuclear-recoil energy depositions are detected by ionization and phonon sensors. Neutrons produce a similar spectrum of low-energy nuclear recoils in such detectors, while most other backgrounds produce electron recoils. The absolute energy scale for nuclear recoils is necessary to interpret results correctly. The energy scale can be determined in CDMS II silicon detectors using neutrons incident from a broad-spectrum $^{252}$Cf source, taking advantage of a prominent resonance in the neutron elastic scattering cross section of silicon at a recoil (neutron) energy near 20 (182) keV. Results indicate that the phonon collection efficiency for nuclear recoils is $4.8^{+0.7}_{-0.9}$% lower than for electron recoils of the same energy. Comparisons of the ionization signals for nuclear recoils to those measured previously by other groups at higher electric fields indicate that the ionization collection efficiency for CDMS II silicon detectors operated at $\\sim$4 V/cm is consistent with 100% for nuclear recoils below 20 keV and gradually decreases for larger energies to $\\sim$75% at 100 keV. The impact of these measurements on previously published CDMS II silicon results is small.
Nuclear pasta in hot dense matter and its implications for neutrino scattering
Roggero, Alessandro; Margueron, Jérôme; Roberts, Luke F.; Reddy, Sanjay
2018-04-01
The abundance of large clusters of nucleons in neutron-rich matter at subnuclear density is found to be greatly reduced by finite-temperature effects when matter is close to β equilibrium, compared to the case where the electron fraction is fixed at Ye>0.1 , as often considered in the literature. Large nuclei and exotic nonspherical nuclear configurations called pasta, favored in the vicinity of the transition to uniform matter at T =0 , dissolve at a relatively low temperature Tu as protons leak out of nuclei and pasta. For matter at β equilibrium with a negligible neutrino chemical potential we find that Tuβ≃4 ±1 MeV for realistic equations of state. This is lower than the maximum temperature Tmaxβ≃9 ±1 MeV at which nuclei can coexist with a gas of nucleons and can be explained by a change in the nature of the transition to uniform matter called retrograde condensation. An important new finding is that coherent neutrino scattering from nuclei and pasta makes a modest contribution to the opacity under the conditions encountered in supernovas and neutron star mergers. This is because large nuclear clusters dissolve at most relevant temperatures, and at lower temperatures, when clusters are present, Coulomb correlations between them suppress coherent neutrino scattering off individual clusters. Implications for neutrino signals from galactic supernovas are briefly discussed.
International Nuclear Information System (INIS)
Xu Jun; Ma Hongru; Chen Liewen; Li Baoan
2008-01-01
Thermal properties of asymmetric nuclear matter are studied within a self-consistent thermal model using an isospin and momentum-dependent interaction (MDI) constrained by the isospin diffusion data in heavy-ion collisions, a momentum-independent interaction (MID), and an isoscalar momentum-dependent interaction (eMDYI). In particular, we study the temperature dependence of the isospin-dependent bulk and single-particle properties, the mechanical and chemical instabilities, and liquid-gas phase transition in hot asymmetric nuclear matter. Our results indicate that the temperature dependence of the equation of state and the symmetry energy are not so sensitive to the momentum dependence of the interaction. The symmetry energy at fixed density is found to generally decrease with temperature and for the MDI interaction the decrement is essentially due to the potential part. It is further shown that only the low momentum part of the single-particle potential and the nucleon effective mass increases significantly with temperature for the momentum-dependent interactions. For the MDI interaction, the low momentum part of the symmetry potential is significantly reduced with increasing temperature. For the mechanical and chemical instabilities as well as the liquid-gas phase transition in hot asymmetric nuclear matter, our results indicate that the boundaries of these instabilities and the phase-coexistence region generally shrink with increasing temperature and are sensitive to the density dependence of the symmetry energy and the isospin and momentum dependence of the nuclear interaction, especially at higher temperatures
Description of a nucleon in nuclear matter using the chiral bag model
International Nuclear Information System (INIS)
Bunatyan, G.G.
1990-01-01
The chiral bag (cloudy bag) model, which contains an essentially nonlinear interaction of quarks with both the classical and quantum pion field, is extended for description of a nucleon in nuclear matter. The dependence on the density and temperature of the medium is studied. The pion field in nuclear matter differs considerably from the free field, and this leads to a modification of the nucleon bag. Increase of the density ρ and temperature T causes strengthening of the pion field and growth of its thermodynamic fluctuations. At sufficiently high densities ρ approx-gt ρ CB and temperatures T≥T cr this leads to instability of the three-quark nucleon bag. Under such conditions nuclear matter cannot be composed only of nucleons, and one should expect the appearance of a different, non-nucleon, phase. Estimates of the critical density and temperature are obtained: ρ CB ∼ (1.5-2)ρ 0 and T cr ∼ 200 MeV (where ρ 0 is the conventional nuclear density)
Chiral approach to nuclear matter: Role of explicit short-range NN-terms
International Nuclear Information System (INIS)
Fritsch, S.; Kaiser, N.
2004-01-01
We extend a recent chiral approach to nuclear matter by including the most general (momentum-independent) NN-contact interaction. Iterating this two-parameter contact vertex with itself and with one-pion exchange the emerging energy per particle exhausts all terms possible up to and including fourth order in the small momentum expansion. Two (isospin-dependent) cut-offs Λ 0,1 are introduced to regularize the (linear) divergences of some three-loop in-medium diagrams. The equation of state of pure neutron matter, anti E n (k n ), can be reproduced very well up to quite high neutron densities of ρ n =0.5 fm -3 by adjusting the strength of a repulsive nn-contact interaction. Binding and saturation of isospin-symmetric nuclear matter is a generic feature of our perturbative calculation. Fixing the maximum binding energy per particle to - anti E(k f0 )=15.3 MeV we find that any possible equilibrium density ρ 0 lies below ρ 0 max =0.191 fm -3 . The additional constraint from the neutron matter equation of state leads however to a somewhat too low saturation density of ρ 0 =0.134 fm -3 . We also investigate the effects of the NN-contact interaction on the complex single-particle potential U(p,k f )+iW(p,k f ). We find that the effective nucleon mass at the Fermi surface is bounded from below by M * (k f0 ) ≥1.4 M. This property keeps the critical temperature of the liquid-gas phase transition at somewhat too high values T c ≥21 MeV. The downward bending of the asymmetry energy A(k f ) above nuclear-matter saturation density is a generic feature of the approximation to fourth order. We furthermore investigate the effects of the NN-contact interaction on the (vector-∇ρ) 2 -term in the nuclear energy density functional E[ρ,τ]. Altogether, there is within this complete fourth-order calculation no ''magic'' set of adjustable short-range parameters with which one could reproduce simultaneously and accurately all semi-empirical properties of nuclear matter. In
Phase transition in dense nuclear matter with quark and gluon condensates
International Nuclear Information System (INIS)
Ellis, J.; Kapusta, J.I.; Olive, K.A.
1991-01-01
Nuclear matter is expected to modify the expectation values of the quark and gluon condensates. We utilize the chiral and scale symmetries of QCD to describe the interaction between these condensates and hadrons. We solve the resulting equations self-consistently in the relativistic mean field approximation. In order that these QCD condensates be driven towards zero at high density their coupling to sigma and vector mesons must be such that the masses of these mesons do not decrease with density. In this case a physically sensible phase transition to quark matter ensures. (orig.)
2010-12-01
... NUCLEAR REGULATORY COMMISSION [EA-10-152; Project No. 52-0001; NRC-2010-0368] In the Matter of Toshiba America Nuclear Energy Corporation and All Other Persons Who Seek or Obtain Access to Safeguards... protect SGI (73 FR 63546). The NRC is issuing this Order to Toshiba America Nuclear Energy Corporation...
2011-03-02
... NUCLEAR REGULATORY COMMISSION [Docket Nos. 52-029-COL, 52-030-COL] In the Matter of Progress Energy Florida, Inc. (Combined License Application, Levy County Nuclear Power Plant, Units 1 and 2... by the Nuclear Regulatory Commission staff in this case. Mr. Dehmel has not previously performed any...
2013-03-05
... NUCLEAR REGULATORY COMMISSION [NRC-2012-0310; Docket Nos. 50-445 and 50-446; License Nos. NPF-87 and NPF-89] In the Matter of Luminant Generation Company LLC, Comanche Peak Nuclear Power Plant, Units... Nuclear Power Plant, Units 1 and 2 (CPNPP), and its Independent Spent Fuel Storage Installation Facility...
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)
Braenzel, J.; Barriga-Carrasco, M. D.; Morales, R.; Schnürer, M.
2018-05-01
We investigate, both experimentally and theoretically, how the spectral distribution of laser accelerated carbon ions can be filtered by charge exchange processes in a double foil target setup. Carbon ions at multiple charge states with an initially wide kinetic energy spectrum, from 0.1 to 18 MeV, were detected with a remarkably narrow spectral bandwidth after they had passed through an ultrathin and partially ionized foil. With our theoretical calculations, we demonstrate that this process is a consequence of the evolution of the carbon ion charge states in the second foil. We calculated the resulting spectral distribution separately for each ion species by solving the rate equations for electron loss and capture processes within a collisional radiative model. We determine how the efficiency of charge transfer processes can be manipulated by controlling the ionization degree of the transfer matter.
International Nuclear Information System (INIS)
Xin Jing; Tang Huaqing; Zhang Yinghua; Zhang Limin
2009-01-01
A risk assessment model of nuclear accident emergency protection countermeasure based on fuzzy matter-element analysis and Euclid approach degree is proposed in the paper. The weight of assessed index is determined by information entropy and the scoring by experts, which could not only make full use of the inherent information of the indexes adequately, but reduce subjective assumption in the course of assessment effectively. The applied result shows that it is reasonable that the model is adopted to make risk assessment for nuclear accident emergency protective countermeasure,and it could be a kind of effective analytical method and decision making basis to choose the optimum protection countermeasure. (authors)
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.)
From meson- and photon-nucleon scattering to vector mesons in nuclear matter
International Nuclear Information System (INIS)
Wolf, Gy.; Lutz, M.F.M.; Friman, B.
2003-01-01
A relativistic and unitary approach to pion- and photon-nucleon scattering taking into account the πN, ρN, ωN, ηN, πΔ, KΛ and KΣ channels is presented. The scheme dynamically generates the s- and d-wave baryon resonances N(1535), N(1650), N(1520) and N(1700) and as well as Δ(1620) and Δ(1700) in terms of quasi-local two-body interaction terms. A fair description of the experimental data relevant to the properties of slow vector mesons in nuclear matter is obtained. The resulting s-wave ρ- and ω-meson-nucleon scattering amplitudes which define the leading density modification of the ρ- and ω-meson spectral functions in nuclear matter are presented. (author)
Inhomogeneous condensates in dilute nuclear matter and BCS-BEC crossovers
International Nuclear Information System (INIS)
Stein, Martin; Sedrakian, Armen; Huang, Xu-Guang; Clark, John W; Röpke, Gerd
2014-01-01
We report on recent progress in understanding pairing phenomena in low-density nuclear matter at small and moderate isospin asymmetry. A rich phase diagram has been found comprising various superfluid phases that include a homogeneous and phase-separated BEC phase of deuterons at low density and a homogeneous BCS phase, an inhomogeneous LOFF phase, and a phase-separated BCS phase at higher densities. The transition from the BEC phases to the BCS phases is characterized in terms of the evolution, from strong to weak coupling, of the condensate wavefunction and the second moment of its density distribution in r-space. We briefly discuss approaches to higher-order clustering in low-density nuclear matter.
Two-loop corrections for nuclear matter in the Walecka model
International Nuclear Information System (INIS)
Furnstahl, R.J.; Perry, R.J.; Serot, B.D.; Department of Physics, The Ohio State University, Columbus, Ohio 43210; Physics Department and Nuclear Theory Center, Indiana University, Bloomington, Indiana 47405)
1989-01-01
Two-loop corrections for nuclear matter, including vacuum polarization, are calculated in the Walecka model to study the loop expansion as an approximation scheme for quantum hadrodynamics. Criteria for useful approximation schemes are discussed, and the concepts of strong and weak convergence are introduced. The two-loop corrections are evaluated first with one-loop parameters and mean fields and then by minimizing the total energy density with respect to the scalar field and refitting parameters to empirical nuclear matter saturation properties. The size and nature of the corrections indicate that the loop expansion is not convergent at two-loop order in either the strong or weak sense. Prospects for alternative approximation schemes are discussed
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
International Nuclear Information System (INIS)
Sun, Baoxi; Lu, Xiaofu; Shen, Pengnian; Zhao, Enguang
2003-01-01
The Debye screening masses of the σ, ω and neutral ρ mesons and the photon are calculated in the relativistic mean-field approximation. As the density of the nucleon increases, all the screening masses of mesons increase. A different result with Brown–Rho scaling is shown, which implies a reduction in the mass of all the mesons in the nuclear matter, except the pion. Replacing the masses of the mesons with their corresponding screening masses in the Walecka-1 model, five saturation properties of the nuclear matter are fixed reasonably, and then a density-dependent relativistic mean-field model is proposed without introducing the nonlinear self-coupling terms of mesons. (author)
Analysis of the doubly heavy baryons in the nuclear matter with the QCD sum rules
International Nuclear Information System (INIS)
Wang, Zhi-Gang
2012-01-01
In this article, we study the doubly heavy baryon states Ξ cc , Ω cc , Ξ bb and Ω bb in the nuclear matter using the QCD sum rules, and derive three coupled QCD sum rules for the masses, vector self-energies and pole residues. The predictions for the mass-shifts in the nuclear matter ΔM Ξ cc =-1.11simGeV, ΔM Ω cc =-0.33∝GeV, ΔM Ξ bb =-3.37∝GeV and ΔM Ω bb =-1.05∝GeV can be confronted with experimental data in the future. (orig.)
NDM06: 2. symposium on neutrinos and dark matter in nuclear physics
Energy Technology Data Exchange (ETDEWEB)
Akerib, D; Arnold, R; Balantekin, A; Barabash, A; Barnabe, H; Baroni, S; Baussan, E; Bellini, F; Bobisut, F; Bongrand, M; Brofferio, Ch; Capolupo, A; Enrico, Carrara; Caurier, E; Cermak, P; Chardin, G; Civitarese, O; Couchot, F; Kerret, H de; Heros, C de los; Detwiler, J; Dracos, M; Drexlin, G; Efremenko, Y; Ejiri, H; Falchini, E; Fatemi-Ghomi, N; Finger, M Ch; Finger Miroslav, Ch; Fiorillo, G; Fiorini, E; Fracasso, S; Frekers, D; Fushimi, K I; Gascon, J; Genest, M H; Georgadze, A; Giuliani, A; Goeger-Neff, M; Gomez-Cadenas, J J; Greenfield, M; H de Jesus, J; Hallin, A; Hannestad, St; Hirai, Sh; Hoessl, J; Ianni, A; Ieva, M B; Ishihara, N; Jullian, S; Kaim, S; Kajino, T; Kayser, B; Kochetov, O; Kopylov, A; Kortelainen, M; Kroeninger, K; Lachenmaier, T; Lalanne, D; Lanfranchi, J C; Lazauskas, R; Lemrani, A R; Li, J; Mansoulie, B; Marquet, Ch; Martinez, J; Mirizzi, A; Morfin Jorge, G; Motz, H; Murphy, A; Navas, S; Niedermeier, L; Nishiura, H; Nomachi, M; Nones, C.; Ogawa, H; Ogawa, I; Ohsumi, H; Palladino, V; Paniccia, M; Perotto, L; Petcov, S; Pfister, S; Piquemal, F; Poves, A; Praet, Ch; Raffelt, G; Ramberg, E; Rashba, T; Regnault, N; Ricol, J St; Rodejohann, W; Rodin, V; Ruz, J; Sander, Ch; Sarazin, X; Scholberg, K; Sigl, G; Simkovic, F; Sousa, A; Stanev, T; Strolger, L; Suekane, F; Thomas, J; Titov, N; Toivanen, J; Torrente-Lujan, E; Tytler, D; Vala, L; Vignaud, D; Vitiello, G; Vogel, P; Volkov, G; Volpe, C; Wong, H; Yilmazer, A
2006-07-01
This second symposium on neutrinos and dark matter is aimed at discussing research frontiers and perspectives on currently developing subjects. It has been organized around 6 topics: 1) double beta decays, theory and experiments (particularly: GERDA, MOON, SuperNEMO, CUORE, CANDLES, EXO, and DCBA), 2) neutrinos and nuclear physics, 3) single beta decays and nu-responses, 4) neutrino astrophysics, 5) solar neutrino review, and 6) neutrino oscillations. This document is made up of the slides of the presentations.
Observation of Δ+→pπ0 decay in nuclear matter
International Nuclear Information System (INIS)
Matulewicz, T.; Aphecetche, L.; Charbonnier, Y.; Delagrange, H.; Martinez, G.; Schutz, Y.; Marques, F.M.
1997-01-01
The Δ baryonic resonances production and decay in nuclear matter have been studied. The heavy ion reaction of 180 A MeV Ar beam on Ca target was used to create the Δ resonances (at SIS GSI Darmstadt). The decay of Δ was measured by means of neutral pion π 0 decay product, two gamma quanta, registration. The Δ resonance invariant mass distribution has been determined
NDM06: 2. symposium on neutrinos and dark matter in nuclear physics
International Nuclear Information System (INIS)
Akerib, D.; Arnold, R.; Balantekin, A.; Barabash, A.; Barnabe, H.; Baroni, S.; Baussan, E.; Bellini, F.; Bobisut, F.; Bongrand, M.; Brofferio, Ch.; Capolupo, A.; Carrara Enrico; Caurier, E.; Cermak, P.; Chardin, G.; Civitarese, O.; Couchot, F.; Kerret, H. de; Heros, C. de los; Detwiler, J.; Dracos, M.; Drexlin, G.; Efremenko, Y.; Ejiri, H.; Falchini, E.; Fatemi-Ghomi, N.; Finger, M.Ch.; Finger Miroslav, Ch.; Fiorillo, G.; Fiorini, E.; Fracasso, S.; Frekers, D.; Fushimi, K.I.; Gascon, J.; Genest, M.H.; Georgadze, A.; Giuliani, A.; Goeger-Neff, M.; Gomez-Cadenas, J.J.; Greenfield, M.; H de Jesus, J.; Hallin, A.; Hannestad, St.; Hirai, Sh.; Hoessl, J.; Ianni, A.; Ieva, M.B.; Ishihara, N.; Jullian, S.; Kaim, S.; Kajino, T.; Kayser, B.; Kochetov, O.; Kopylov, A.; Kortelainen, M.; Kroeninger, K.; Lachenmaier, T.; Lalanne, D.; Lanfranchi, J.C.; Lazauskas, R.; Lemrani, A.R.; Li, J.; Mansoulie, B.; Marquet, Ch.; Martinez, J.; Mirizzi, A.; Morfin Jorge, G.; Motz, H.; Murphy, A.; Navas, S.; Niedermeier, L.; Nishiura, H.; Nomachi, M.; Nones, C.; Ogawa, H.; Ogawa, I.; Ohsumi, H.; Palladino, V.; Paniccia, M.; Perotto, L.; Petcov, S.; Pfister, S.; Piquemal, F.; Poves, A.; Praet, Ch.; Raffelt, G.; Ramberg, E.; Rashba, T.; Regnault, N.; Ricol, J.St.; Rodejohann, W.; Rodin, V.; Ruz, J.; Sander, Ch.; Sarazin, X.; Scholberg, K.; Sigl, G.; Simkovic, F.; Sousa, A.; Stanev, T.; Strolger, L.; Suekane, F.; Thomas, J.; Titov, N.; Toivanen, J.; Torrente-Lujan, E.; Tytler, D.; Vala, L.; Vignaud, D.; Vitiello, G.; Vogel, P.; Volkov, G.; Volpe, C.; Wong, H.; Yilmazer, A.
2006-01-01
This second symposium on neutrinos and dark matter is aimed at discussing research frontiers and perspectives on currently developing subjects. It has been organized around 6 topics: 1) double beta decays, theory and experiments (particularly: GERDA, MOON, SuperNEMO, CUORE, CANDLES, EXO, and DCBA), 2) neutrinos and nuclear physics, 3) single beta decays and nu-responses, 4) neutrino astrophysics, 5) solar neutrino review, and 6) neutrino oscillations. This document is made up of the slides of the presentations
Hot metastable state of abnormal matter in relativistic nuclear field theory
International Nuclear Information System (INIS)
Glendenning, N.K.
1987-01-01
Because of their non-linearity, the field equations of relativistic nuclear field theory admit of additional solutions besides the normal state of matter. One of these is a finite-temperature abnormal phase. Over a narrow range in temperature, matter can exist in the abnormal phase at zero pressure. This is a hot metastable state, for which there is a barrier against decay, because the field configuration is different than in the normal state, the baryon masses are far removed from their vacuum masses, there is an abundance of pairs also far removed from their vacuum masses, and a correspondingly high entropy. The abundance of baryon-antibaryon pairs is the glue that holds this matter together. The signals associated with this novel state are quite unusual. A fragment of such matter will cool by emitting a spectrum of black-body radiation, consisting principally of photons, lepton pairs and pions, rather than by baryon emission, because the latter are far removed from their vacuum masses. If produced at the upper end of its temperature range, a large fraction of the original energy, more than half in the examples studied here, is radiated in this way. The baryons and light elements produced in the eventual decay, after the abnormal matter has cooled to a domain where its pressure becomes positive, will account for only a fraction of the original energy. The energy domain of this state depends sensitively on the coupling constants, and within a reasonable range as determined by nuclear matter properties, can lie in the range of GeV to tens of GeV per nucleon. (orig.)
Global security and the impacts in nuclear matter control: Nuclear Security Summit 2016
International Nuclear Information System (INIS)
Lima, Martonio Mont’Alverne Barreto; Barreto, Midred Cavalcante
2017-01-01
Due to the current international security instability, especially resulting from traffic and nuclear terrorism threat proliferation, the Nuclear Security Summits were conceived with the objective of increasing the cooperation between States, institutions and international organisms, as well as conducting a global community in following the guidelines and action plans which have produced curious results such as the reduction and the removal of enriched uranium in some countries, the reinforcement of safeguard installations that store radioactive materials and the establishment of Excellence Centers, qualification, training and technological development in the fight against nuclear weaponry traffic. (author)
Global security and the impacts in nuclear matter control: Nuclear Security Summit 2016
Energy Technology Data Exchange (ETDEWEB)
Lima, Martonio Mont’Alverne Barreto; Barreto, Midred Cavalcante, E-mail: barreto@unifor.br, E-mail: midredcb@hotmail.com [Universidade de Fortaleza (UNIFOR), CE (Brazil)
2017-07-01
Due to the current international security instability, especially resulting from traffic and nuclear terrorism threat proliferation, the Nuclear Security Summits were conceived with the objective of increasing the cooperation between States, institutions and international organisms, as well as conducting a global community in following the guidelines and action plans which have produced curious results such as the reduction and the removal of enriched uranium in some countries, the reinforcement of safeguard installations that store radioactive materials and the establishment of Excellence Centers, qualification, training and technological development in the fight against nuclear weaponry traffic. (author)
Saturation properties of asymmetric nuclear matter to be obtained from unstable nuclei
Energy Technology Data Exchange (ETDEWEB)
Oyamatsu, Kazuhiro [Aichi Shukutoku Univ., Dept. of Media Production and Theories, Nagakute, Aichi (Japan); Iida, Kei [Institute of Physical and Chemical Research, Wako, Saitama (Japan)
2002-09-01
We examine relations among the parameters characterizing the phenomenological equation of state (EOS) of nearly symmetric, uniform nuclear matter near the saturation density from experimental data on radii and masses of stable nuclei. The EOS parameters of interest are the symmetry energy S{sub 0}, the symmetry energy density-derivative coefficient L and the incompressibility K{sub 0} at the normal nuclear density. The calculations of the nuclear properties were performed with a simplified Thomas-Fermi model. We find a constraint on (K{sub 0}, L) values from the slope of the saturation line (the line joining the saturation points of asymmetric matter EOS with fixed proton abundance). A strong correlation between S{sub 0} and L, which was discussed in the Skyrme Hartree-Fock theory for relatively small L values, is found to hold for such larger values as a relativistic mean field theory predicts. In the light of the uncertainties in the (K{sub 0}, L) values, we calculate radii of unstable nuclei as expected to be produced in future facilities. We find that the matter radii depend strongly on L almost independently of K{sub 0}, and that systematic detection of the radii of such nuclei will help to determine the L value. (author)
Effects of Brown-Rho scalings in nuclear matter, neutron stars and finite nuclei
Kuo, T. T. S.; Dong, Huan
2011-01-01
We have carried out calculations for nuclear matter, neutron stars and finite nuclei using NN potentials with and without the medium-dependent modifications based on the Brown-Rho (BR) scalings. Using the Vlow-k low-momentum interactions derived from such potentials, the equations of state (EOS) for symmetric and asymmetric nuclear matter, for densities up to ~ 5ρ0, are calculated using a RPA method where the particle-particle hole-hole ring diagrams are summed to all orders. The medium effects from both a linear BR scaling (BR1) and a non-linear one (BR2) are considered, and they both are essential for our EOSs to reproduce the nuclear matter saturation properties. For densities ρ below ρ0, results from BR1 and BR2 are close to each other. For higher densities, the EOS given by BR2 is more desirable and is well reproduced by that given by the interaction (Vlow-k+TBF) where Vlow-k is the unsealed low-momentum interaction and TBF is an empirical Skyrme three-body force. The moment of inertia of neutron stars is ~ 60 and ~ 25Modotkm2 respectively with and without the inclusion of the above BR2 medium effects. Effects from the BR scaling are important for the long half-life, ~ 5000yrs, of the 14C - 14N β-decay.
The single-particle potential of nuclear matter in the LOCV framework
Energy Technology Data Exchange (ETDEWEB)
Modarres, M., E-mail: mmodares@ut.ac.ir [Physics Department, University of Tehran, North-Kargar Ave., 1439955961 Tehran (Iran, Islamic Republic of); Rajabi, A. [Physics Department, Shahid Rajaei Teacher Training University, Lavizan, 16788 Tehran (Iran, Islamic Republic of)
2011-10-01
The density and momentum dependence of single-particle potential (SPP) and effective mass of symmetric nuclear matter are studied in the framework of lowest order constrained variational (LOCV) method. The Reid68, the Reid68-{Delta} and the Av{sub 18} interactions are considered as the input nucleon-nucleon potentials. It is shown that the SPP of nuclear matter, at fixed density, is an increasing function of nucleon momentum, and it has different behavior for the Reid type potentials with respect to Av{sub 18} interaction. We find good agreements between our LOCV SPP and those coming from others many-body techniques such as the (Dirac-)Brueckner-Hartree-Foch ((D)BHF), the fermion hypernetted chain (FHNC), mean field (MF), etc. On the other hand SPP dramatically depends on the density at low and high nucleon momentums. While the effective mass of nuclear matter increases as we increase the nucleon momentum, it decreases at the Fermi surface. Again, good agreements are observed between our calculated effective mass and those coming from the methods mentioned above.
Effective interactions and mean field theory: from nuclear matter to nuclei
International Nuclear Information System (INIS)
Cochet, B.
2005-07-01
The Skyrme force is a zero-range force that allows the construction of the mean field inside the nucleus in a simple way. Skyrme forces are reasonably predictive but some features of the infinite nuclear matter or the mass of heavy nuclei are not well computed. The aim of this work is to propose an expanded parametrization of the Skyrme force in order to improve its predictive power. The first part is dedicated to the construction of the expansion of the parametrization. We recall how the effective forces are linked to the nucleon-nucleon interaction then we show the limits of the standard Skyrme forces and we propose a relatively natural improvements based on the integration of spin and isospin instabilities. The second part deals with the validation of the model, first by describing infinite nuclear matter then by studying β-balanced nuclear matter which has enabled us to reproduce some features of neutron stars like mass and radius. The computation of properties of nuclei like binding energy, mass, radii depends strongly on the adjustment procedure. (A.C.)
Tensor Fermi liquid parameters in nuclear matter from chiral effective field theory
Holt, J. W.; Kaiser, N.; Whitehead, T. R.
2018-05-01
We compute from chiral two- and three-body forces the complete quasiparticle interaction in symmetric nuclear matter up to twice nuclear matter saturation density. Second-order perturbative contributions that account for Pauli blocking and medium polarization are included, allowing for an exploration of the full set of central and noncentral operator structures permitted by symmetries and the long-wavelength limit. At the Hartree-Fock level, the next-to-next-to-leading order three-nucleon force contributes to all noncentral interactions, and their strengths grow approximately linearly with the nucleon density up to that of saturated nuclear matter. Three-body forces are shown to enhance the already strong proton-neutron effective tensor interaction, while the corresponding like-particle tensor force remains small. We also find a large isovector cross-vector interaction but small center-of-mass tensor interactions in the isoscalar and isovector channels. The convergence of the expansion of the noncentral quasiparticle interaction in Landau parameters and Legendre polynomials is studied in detail.
International Nuclear Information System (INIS)
2005-01-01
Following the success of INAC 2002 which was inaugurated in Rio de Janeiro, INAC 2005 has been held with the 14th Meeting on Reactor Physics and Thermal Hydraulics (XIV ENFIR) and the 7th Meeting on Nuclear Applications (VII ENAN). A key goal of these joint meetings is to bring together scientists to exchange the latest research and development (R and D) information in nuclear science and technology. In the INAC 2005 technical program, plenary sessions, such as round table discussions and keynote lectures, has held to present to the general public the recent advances of peaceful nuclear energy usage, reducing the global warming. Besides, INAC 2005 has offered a poster technical session on Management Systems for Nuclear Organizations. The XIV ENFIR has covered all aspects of interdisciplinary R and D related to nuclear reactors, and the VII ENAN has offered a forum for discussion on nuclear applications in industry, geology, agriculture, medicine, biology and environmental sciences. Both ENFIR and ENAN have also organized oral and poster technical sessions
International Nuclear Information System (INIS)
Mori, Shunsuke
2012-01-01
This paper presents an evaluation of global warming mitigation options based on scenarios from the Asian Modeling Exercise. Using an extended version of the integrated assessment model MARIA-23 (Multiregional Approach for Resource and Industry Allocation), we analyze nuclear fuel recycling options, carbon capture and storage technologies (CCS), and biomass utilization. To assess the potential implications of decreased social acceptance of nuclear power in the wake of the Fukushima nuclear accident, additional scenarios including a nuclear power expansion limitation, are analyzed. We also evaluate MARIA-23 model simulation estimates of long-term contributions and interrelationships among nuclear power, biomass, and CCS. Finally, potential costs of nuclear limitation under carbon control policies are assessed. The simulation results in this paper suggest the following: (1) under the reference scenario, global GDP losses in climate limitation scenarios range from 1.3% per year to 3.9% per year in 2060, rising to between 3.5% per year and 4.5% per year in 2100; (2) the use of nuclear fuel reprocessing technologies increase rapidly in all carbon control policy scenarios; (3) under a scenario where the price of CO 2 is $30 and nuclear power expansion is strictly limited, GDP losses increase significantly—from 4.5% per year to 6.4% per year by 2100; (4) nuclear power and CCS are substitute mitigation technologies. With nuclear power technology available CCS deployment reaches approximately 15,000 Mt-CO 2 per year by 2010; without a nuclear power option, CCS deployment rises to more than 80,000 Mt-CO 2 per year; and (5) biomass utilization cannot fully compensate for limitations to nuclear power expansion in policy scenarios. In addition to examining the role of these three technologies on global scales, we report results for several major Asian regions, namely Japan, China, and India. China tends to deploy nuclear power (if available) in response to rapidly growing
Finite size effects in liquid-gas phase transition of asymmetric nuclear matter
International Nuclear Information System (INIS)
Pawlowski, P.
2001-01-01
Full text: Since the nuclear equation of state has been studied in astrophysical context as an element of neutron star or super-nova theories - a call for an evidence was produced in experimental nuclear physics. Heavy-ion collisions became a tool of study on thermodynamic properties of nuclear matter. A particular interest has been inspired here by critical behavior of nuclear systems, as a phase transition of liquid-gas type. A lot of efforts was put to obtain an experimental evidence of such a phenomenon in heavy-ion collisions. With the use of radioactive beams and high performance identification systems in a near future it will be possible to extend experimental investigation to asymmetric nuclear systems, where neutron-to-proton ratio is far from the stability line. This experimental development needs a corresponding extension of theoretical studies. To obtain a complete theory of the liquid-gas phase transition in small nuclear systems, produced in violent heavy-ion collisions, one should take into account two facts. First, that the nuclear matter forming nuclei is composed of protons and neutrons; this complicates the formalism of phase transitions because one has to deal with two separate, proton and neutron, densities and chemical potentials. The second and more important is that the surface effects are very strong in a system composed of a few hundreds of nucleons. This point is especially difficult to hold, because surface becomes an additional, independent state parameter, depending strongly on the geometrical configuration of the system, and introducing a non-local term in the equation of state. In this presentation we follow the recent calculation by Lee and Mekjian on the finite-size effects in small (A = 10 2 -10 3 ) asymmetric nuclear systems. A zero-range isospin-dependent Skyrme force is used to obtain a density and isospin dependent potential. The potential is then completed by additional terms giving contributions from surface and Coulomb
Measurement of Quark Energy Loss in Cold Nuclear Matter at Fermilab E906/SeaQuest
Energy Technology Data Exchange (ETDEWEB)
Lin, Po-Ju [Univ. of Colorado, Boulder, CO (United States)
2017-01-01
Parton energy loss is a process within QCD that draws considerable interest. The measurement of parton energy loss can provide valuable information for other hard-scattering processes in nuclei, and also serves as an important tool for exploring the properties of the quark-gluon plasma (QGP). Quantifying the energy loss in cold nuclear matter will help to set a baseline relative to energy loss in the QGP. With the Drell-Yan process, the energy loss of incoming quarks in cold nuclear matter can be ideally investigated since the final state interaction is expected to be minimal. E906/SeaQuest is a fixed-target experiment using the 120 GeV proton beam from the Fermilab Main Injector and has been collecting data from p+p, p+d, p+C, p+Fe, and p+W collisions. Within the E906 kinematic coverage of Drell-Yan production via the dimuon channel, the quark energy loss can be measured in a regime where other nuclear effects are expected to be small. In this thesis, the study of quark ener gy loss from different cold nuclear targets is presented.
Nuclear matter studies with density-dependent meson-nucleon coupling constants
International Nuclear Information System (INIS)
Banerjee, M.K.; Tjon, J.A.; Banerjee, M.K.; Tjon, J.A.
1997-01-01
Due to the internal structure of the nucleon, we should expect, in general, that the effective meson nucleon parameters may change in nuclear medium. We study such changes by using a chiral confining model of the nucleon. We use density-dependent masses for all mesons except the pion. Within a Dirac-Brueckner analysis, based on the relativistic covariant structure of the NN amplitude, we show that the effect of such a density dependence in the NN interaction on the saturation properties of nuclear matter, while not large, is quite significant. Due to the density dependence of the g σNN , as predicted by the chiral confining model, we find, in particular, a looping behavior of the binding energy at saturation as a function of the saturation density. A simple model is described, which exhibits looping and which is shown to be mainly caused by the presence of a peak in the density dependence of the medium modified σN coupling constant at low density. The effect of density dependence of the coupling constants and the meson masses tends to improve the results for E/A and density of nuclear matter at saturation. From the present study we see that the relationship between binding energy and saturation density may not be as universal as found in nonrelativistic studies and that more model dependence is exhibited once medium modifications of the basic nuclear interactions are considered. copyright 1997 The American Physical Society
Xu, Yangyang; Lamarque, Jean-François
2018-03-01
Particulate matter with the diameter smaller than 2.5 μm (PM2.5) poses health threats to human population. Regardless of efforts to regulate the pollution sources, it is unclear how climate change caused by greenhouse gases (GHGs) would affect PM2.5 levels. Using century-long ensemble simulations with Community Earth System Model 1 (CESM1), we show that, if the anthropogenic emissions would remain at the level in the year 2005, the global surface concentration and atmospheric column burden of sulfate, black carbon, and primary organic carbon would still increase by 5%-10% at the end of 21st century (2090-2100) due to global warming alone. The decrease in the wet removal flux of PM2.5, despite an increase in global precipitation, is the primary cause of the increase in the PM2.5 column burden. Regionally over North America and East Asia, a shift of future precipitation toward more frequent heavy events contributes to weakened wet removal fluxes. Our results suggest climate change impact needs to be accounted for to define the future emission standards necessary to meet air quality standard.
Xu, Y.; Lamarque, J. F.; Wu, X.
2017-12-01
Particulate matter with the diameter smaller than 2.5 micrometers (PM2.5) poses health threats to human populations. Regardless of efforts to regulate the pollution sources, it is unclear how climate change caused by greenhouse gases (GHGs) would affect PM2.5 levels. Using century-long ensemble simulations with Community Earth System Model 1 (CESM1), we show that, if the anthropogenic emissions would remain at the level in the year 2005, the global surface concentration and atmospheric column burden of sulfate, black carbon, and primary organic carbon would still increase by 5-10% at the end of 21st century (2090-2100) due to global warming alone. The decrease in the wet removal flux of PM2.5, despite an increase in global precipitation, is the primary cause for the increase in the PM2.5 column burden. Regionally over North America and East Asia, a shift of future precipitation toward more frequent heavy events contributes to weakened wet removal fluxes. Based on the daily model output, the frequency and intensity of extreme pollution events are also studied. We found that both stagnation frequency and rainfall changes serve to worsen extreme pollution in the future.
General aspects of the nucleon-nucleon interaction and nuclear matter properties
Energy Technology Data Exchange (ETDEWEB)
Plohl, Oliver
2008-07-25
The subject of the present thesis is at first the investigation of model independent properties of the nucleon-nucleon (NN) interaction in the vacuum concerning the relativistic structure and the implications for nuclear matter properties. Relativistic and non-relativistic meson-exchange potentials, phenomenological potentials s well as potentials based on effective field theory (EFT) are therefore mapped on a relativistic operator basis given by the Clifford Algebra. This allows to compare the various approaches at the level of covariant amplitudes where a remarkable agreement is found. Furthermore, the relativistic self-energy is determined in the Hartree-Fock (HF) approximation. The appearance of a scalar and vector field of several hundred MeV magnitude is a general feature of relativistic descriptions of nuclear matter. Within QCD sum rules these fields arise due to the density dependence of chiral condensates. We find that independent of the applied NN interaction large scalar and vector fields are generated when the symmetries of the Lorentz group are restored. In the framework of chiral EFT (chEFT) it is shown, that these fields are generated by short-range next-to-leading order (NLO) contact terms, which are connected to the spin-orbit interaction. To estimate the effect arising from NN correlations the equation of state of nuclear and neutron matter is calculated in the Brueckner-HF (BHF) approximation applying chEFT. Although, as expected, a clear over-binding is found (at NLO a saturating behavior is observed), the symmetry energy shows realistic properties when compared to phenomenological potentials (within the same approximation) and other approaches. The investigation of the pion mass dependence within chEFT at NLO shows that the magnitude of the scalar and vector fields persists in the chiral limit - nuclear matter is still bound. In contrast to the case of a pion mass larger than the physical one the binding energy and saturation density are
General aspects of the nucleon-nucleon interaction and nuclear matter properties
International Nuclear Information System (INIS)
Plohl, Oliver
2008-01-01
The subject of the present thesis is at first the investigation of model independent properties of the nucleon-nucleon (NN) interaction in the vacuum concerning the relativistic structure and the implications for nuclear matter properties. Relativistic and non-relativistic meson-exchange potentials, phenomenological potentials s well as potentials based on effective field theory (EFT) are therefore mapped on a relativistic operator basis given by the Clifford Algebra. This allows to compare the various approaches at the level of covariant amplitudes where a remarkable agreement is found. Furthermore, the relativistic self-energy is determined in the Hartree-Fock (HF) approximation. The appearance of a scalar and vector field of several hundred MeV magnitude is a general feature of relativistic descriptions of nuclear matter. Within QCD sum rules these fields arise due to the density dependence of chiral condensates. We find that independent of the applied NN interaction large scalar and vector fields are generated when the symmetries of the Lorentz group are restored. In the framework of chiral EFT (chEFT) it is shown, that these fields are generated by short-range next-to-leading order (NLO) contact terms, which are connected to the spin-orbit interaction. To estimate the effect arising from NN correlations the equation of state of nuclear and neutron matter is calculated in the Brueckner-HF (BHF) approximation applying chEFT. Although, as expected, a clear over-binding is found (at NLO a saturating behavior is observed), the symmetry energy shows realistic properties when compared to phenomenological potentials (within the same approximation) and other approaches. The investigation of the pion mass dependence within chEFT at NLO shows that the magnitude of the scalar and vector fields persists in the chiral limit - nuclear matter is still bound. In contrast to the case of a pion mass larger than the physical one the binding energy and saturation density are
Janovics, R; Bihari, Á; Papp, L; Dezső, Z; Major, Z; Sárkány, K E; Bujtás, T; Veres, M; Palcsu, L
2014-02-01
Danube water, sediment and various aquatic organisms (snail, mussel, predatory and omnivorous fish) were collected upstream (at a background site) and downstream of the outlet of the warm water channel of Paks Nuclear Power Plant. Gamma emitters, tissue free-water tritium (TFWT) and total organically-bound tritium (T-OBT) measurements were performed. A slight contribution of the power plant to the natural tritium background concentration was measured in water samples from the Danube section downstream of the warm water channel. Sediment samples also contained elevated tritium concentrations, along with a detectable amount of (60)Co. In the case of biota samples, TFWT exhibited only a very slight difference compared to the tritium concentration of the Danube water, however, the OBT was higher than the tritium concentration in the Danube, independent of the origin of the samples. The elevated OBT concentration in the mollusc samples downstream of the warm water channel may be attributed to the excess emission from the nuclear power plant. The whole data set obtained was used for dose rate calculations and will be contributed to the development of the ERICA database. Copyright © 2013 Elsevier Ltd. All rights reserved.
Di-nucleon structures in homogeneous nuclear matter based on two- and three-nucleon interactions
Energy Technology Data Exchange (ETDEWEB)
Arellano, Hugo F. [University of Chile, Department of Physics - FCFM, Santiago (Chile); CEA, DAM, DIF, Arpajon (France); Isaule, Felipe [University of Chile, Department of Physics - FCFM, Santiago (Chile); Rios, Arnau [University of Surrey, Department of Physics, Faculty of Engineering and Physical Sciences, Guildford (United Kingdom)
2016-09-15
We investigate homogeneous nuclear matter within the Brueckner-Hartree-Fock (BHF) approach in the limits of isospin-symmetric nuclear matter (SNM) as well as pure neutron matter at zero temperature. The study is based on realistic representations of the internucleon interaction as given by Argonne v{sub 18}, Paris, Nijmegen I and II potentials, in addition to chiral N{sup 3}LO interactions, including three-nucleon forces up to N{sup 2}LO. Particular attention is paid to the presence of di-nucleon bound states structures in {sup 1}S{sub 0} and {sup 3}SD{sub 1} channels, whose explicit account becomes crucial for the stability of self-consistent solutions at low densities. A characterization of these solutions and associated bound states is discussed. We confirm that coexisting BHF single-particle solutions in SNM, at Fermi momenta in the range 0.13-0.3 fm{sup -1}, is a robust feature under the choice of realistic internucleon potentials. (orig.)
Equation of state of neutron-rich nuclear matter from chiral effective field theory
Energy Technology Data Exchange (ETDEWEB)
Kaiser, Norbert; Strohmeier, Susanne [Technische Universitaet Muenchen (Germany)
2016-07-01
Based on chiral effective field theory, the equation of state of neutron-rich nuclear matter is investigated systematically. The contributing diagrams include one- and two-pion exchange together with three-body terms arising from virtual Δ(1232)-isobar excitations. The proper expansion of the energy per particle, anti E(k{sub f},δ) = anti E{sub n}(k{sub f}) + δB{sub 1}(k{sub f}) + δ{sup 5/3}B{sub 5/3}(k{sub f}) + δ{sup 2}B{sub 2}(k{sub f}) +.., for the system with neutron density ρ{sub n} = k{sub f}{sup 3}(1-δ)/3π{sup 2} and proton density ρ{sub p} = k{sub f}{sup 3}δ/3π{sup 2} is performed analytically for the various interaction contributions. One observes essential structural differences to the commonly used quadratic approximation. The density dependent coefficient B{sub 1}(k{sub f}) turns out to be unrelated to the isospin-asymmetry of nuclear matter. The coefficient B{sub 5/3}(k{sub f}) of the non-analytical δ{sup 5/3}-term receives contributions from the proton kinetic energy and from the one- and two-pion exchange interactions. The physical consequences for neutron star matter are studied.
Peranan Environmental Accounting Terhadap Global Warming
Martusa, Riki
2009-01-01
This article explores about is global warming. The distortion of nature causes global warming. Industrial sector is one of global warming incurred. Some nations create a group to cope this matter. They try to reduce carbon emission as one of global warming causes by controlling industrial carbon emission through financial reporting. This article explores normatively roles of environmental accounting in cope with global warming.
Nonstatic, self-consistent πN t matrix in nuclear matter
International Nuclear Information System (INIS)
Van Orden, J.W.
1984-01-01
In a recent paper, a calculation of the self-consistent πN t matrix in nuclear matter was presented. In this calculation the driving term of the self-consistent equation was chosen to be a static approximation to the free πN t matrix. In the present work, the earlier calculation is extended by using a nonstatic, fully-off-shell free πN t matrix as a starting point. Right-hand pole and cut contributions to the P-wave πN amplitudes are derived using a Low expansion and include effects due to recoil of the interacting πN system as well as the transformation from the πN c.m. frame to the nuclear rest frame. The self-consistent t-matrix equation is rewritten as two integral equations which modify the pole and cut contributions to the t matrix separately. The self-consistent πN t matrix is calculated in nuclear matter and a nonlocal optical potential is constructed from it. The resonant contribution to the optical potential is found to be broadened by 20% to 50% depending on pion momentum and is shifted upward in energy by approximately 10 MeV in comparison to the first-order optical potential. Modifications to the nucleon pole contribution are found to be negligible
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
St. Laurent, Georges; Savva, Yiannis A.; Kapranov, Philipp
2012-01-01
Perhaps no other topic in contemporary genomics has inspired such diverse viewpoints as the 95+% of the genome, previously known as “junk DNA,” that does not code for proteins. Here, we present a theory in which dark matter RNA plays a role in the generation of a landscape of spatial micro-domains coupled to the information signaling matrix of the nuclear landscape. Within and between these micro-domains, dark matter RNAs additionally function to tether RNA interacting proteins and complexes of many different types, and by doing so, allow for a higher performance of the various processes requiring them at ultra-fast rates. This improves signal to noise characteristics of RNA processing, trafficking, and epigenetic signaling, where competition and differential RNA binding among proteins drives the computational decisions inherent in regulatory events. PMID:22539933
Towards Dense Nuclear Matter in A Modified Sakai-Sugimoto Model
Directory of Open Access Journals (Sweden)
Rho Mannque
2012-02-01
Full Text Available As a part of the attempt to address dense baryonic matter, we first review holographic approaches to QCD. The big advantage of the holographic approaches is that they render strongly coupled 4D gauge theories as duals of certain weakly coupled string/supergravity that are well understood. Its relevance to real QCD is one of the central problems in hadron/nuclear physics as well as in the context of applied string theory. None of the models based on these holographic approaches presently available can adequately describe the system we are interested in, namely dense baryonic matter. Nevertheless, some aspects of the holographic approach are found to describe certain processes both in vacuum and in medium. In this talk we only present the structure of a model that appears to be closest to QCD, and has the potential to address the problem.
Neutron star properties and the relativistic nuclear equation of state of many-baryon matter
International Nuclear Information System (INIS)
Weber, F.; Weigel, M.K.
1989-01-01
A relativistic model of baryons interacting via the exchange of σ-, ω-, π- and ρ-mesons (scalar-vector-isovector (SVI) theory) is used to describe the properties of both dense and superdense matter. For the theoretical frame, we used the temperature-dependent Green's function formalism. The equation of state (EOS) is calculated for nuclear as well as neutron matter in the Hartree (H) and Hartree-Fock (HF) approximation. The existence of phase transitions has been investigated. The isotherms of pressure as a function of density show for nuclear matter a critical temperature of about T c HF =16.6 MeV. (As in the usual scalar-vector (SV) theory, the phase transition is absent for neutron matter. A phase transition of both many-baryon systems in the high-pressure and high-density region, which has been found within the SV many-baryon theory, appears in the SVI theory too. The calculated maximum stable masses of neutron stars depend on 1. the underlying parameter set and/or 2. on the chosen approximation (i.e., H, HF; SV-, SVI theory, respectively). Hartree calculations lead to a mass stability limit of M max H ≤2.87 M sun (M max H ≤2.44 M sun when hyperons are taken into account). For the HF calculations we obtained M max HF ≤3.00 M sun (M max HF ≤2.85 M sun ). The corresponding maximum radii are (same notation as above) R H ≤13.2 km (R H ≤11.8 km), R HF ≤14.0 km (R HF ≤13.94 km).) The influence of the approximations, parameter sets and hyperons on the neutron star's moment of inertia is exhibited. (orig.)
DEFF Research Database (Denmark)
da Providëncia, J.; Jalkanen, Karl J.; Bohr, Henrik
2013-01-01
relativistic fluid of elementary particles is studied. We find that the magnetic field of spin polarized matter with densities of 2 to 30, where 0 is the equilibrium density of nuclear matter, is rather huge, of the order of 1017 Gauss. Finally we look at the chiral nature of nuclear forces and interactions...... as they possibly relate to chirality of nuclei (atoms) in molecules as a source of chirality in amino acids and hence in life. Previous works have not investigated the nuclear forces as a possible bias which initiated the bias towards L-amino acids as the building blocks on proteins, and later life....
Microscopic equation of state calculations: 1. Nuclear matter. 2. Liquid helium 3
International Nuclear Information System (INIS)
Heyer, J.P.
1989-01-01
A new method for calculating the equation of state of extended Fermi systems is proposed and applied to nuclear matter and liquid 3 He. New techniques are developed for summing up the particle-particle (pp) and particle-hole (ph) ring diagrams to all orders in the calculation of the ground state shift ΔE 0 for many-body systems. Analytic expressions for ΔE pp P 0 , the contribution from all of the pp ring diagrams to ΔE 0 , and ΔE ph 0 , the corresponding contribution from all of the ph ring diagrams, have been obtained. It has been shown that the pp ring diagram sum may be written as an integral over frequency, involving the particle-particle Green's function. A similar integral expression is derived for the ph ring diagram sum. Two methods are developed for carrying out the frequency integrations, namely the multipole and transition amplitude methods. These methods have been tested on an exactly-solvable many-fermion model, a modified Lipkin model, and compared. The author has studied the instability of nuclear matter at both zero and finite temperature within the pp ring diagram framework. He has found using the Gogny D1 effective nucleon-nucleon interaction, complex eigenvalues of an RPA-type secular equation are obtained in a well-defined temperature-density region. When complex eigenvalues occur, the thermodynamic potential becomes complex. The possible connection between the occurrence of complex eigenvalues and liquid-gas phase separation is discussed. The pp ring diagrams are also found to lower the compression modulus of nuclear matter. Lastly, the pp ring diagram method is applied to the calculation of the ground state energy of normal and spin-polarized liquid 3 He. We have found a binding energy per particle (BE/A) of 1.45 degree K and 1.79 degree K for the normal and spin-polarized systems, respectively
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
International Nuclear Information System (INIS)
Korpa, C.L.; Lutz, M.F.M.; Technische Univ. Darmstadt
2003-06-01
We evaluate the in-medium spectral functions for pions, nucleon and isobar resonances in a self consistent and covariant manner. The calculations are based on a recently developed formulation which leads to predictions in terms of the pion-nucleon scattering phase shifts and a set of Migdal parameters describing important short range correlation effects. We do not observe any significant softening of pion modes if we insist on reasonable isobar resonance properties but predict a considerable broadening of the N(1440) and N(1520) resonances in nuclear matter. (orig.)
Two-body tensor interactions in the nuclear matter response function
International Nuclear Information System (INIS)
Besprosvany, J.
1997-01-01
The inclusive scattering response of nuclear matter is studied in the regime of large momentum transfer q, and around the quasielastic peak. We review interaction corrections to free propagation as embodied in the impulse approximation. Calculations of the two-body and many-body corrections within an eikonal approach are presented. These use an approximated two-body density matrix which takes account of spin and isospin degrees of freedom. Both calculations give similar and sizable corrections at q = 550 MeV and reproduce data extrapolated from finite nuclei; this indicates the relevance of two-body tensor contributions in this regime. (Author)
Upper-bound nature of the Brueckner energy of nuclear matter
International Nuclear Information System (INIS)
Harada, M.
1993-01-01
A trial wavefunction is constructed for nuclear matter in terms of the reaction matrix. The trial function includes only two-particle excitations and the resulting energy expectation value for two-nucleon forces with a state-independent repulsive core of Yukawa shape approaches in the thermodynamic limit the energy given by the lowest order Brueckner theory with standard dispersion. Evaluation of the energy expectation value is carried out in a systematic way by use of an identity that holds between the Hamiltonians and reaction matrix. (Author)
Baryonic forces and hyperons in nuclear matter from SU(3) chiral effective field theory
Energy Technology Data Exchange (ETDEWEB)
Petschauer, Stefan Karl
2016-02-12
In this work the baryon-baryon interaction is studied at next-to-leading order in SU(3) chiral effective field theory and applied to hyperon-nucleon scattering. The properties of hyperons in isospin-symmetric as well as asymmetric nuclear matter are calculated within the Bruecker-Hartree-Fock formalism. Moreover, the leading three-baryon interaction is derived and its low-energy constants are estimated from decuplet intermediate states. We conclude, that chiral effective field theory is a well-suited tool to describe the baryonic forces.
Nuclear matter kinetic coefficients and damping of finite nuclear collective modes
International Nuclear Information System (INIS)
Toledo Piza, A.F.R. de.
1986-06-01
By carrying the general description of one-body observables beyond the mean-field approximation, those correlation terms responsible for Kinetic phenomena and those involved in the renormalization of the G-matrix mean-field in finite nuclei are identified. A Kinetic equation for the one-body density is obtained. Estimates for transport coefficients and for the damping of zero sound are obtained which point to the inadequacy of hydrodynamical descriptions of collective nuclear modes and indicate that collisional damping in large nuclei may account for one or a few tenths of the observed widths. (S.D.) [pt
Ludert, Erin Edkins
While evidence of non-baryonic dark matter has been accumulating for decades, its exact nature continues to remain a mystery. Weakly Interacting Massive Particles (WIMPs) are a well motivated candidate which appear in certain extensions of the Standard Model, independently of dark matter theory. If such particles exist, they should occasionally interact with particles of normal matter, producing a signal which may be detected. The DarkSide-50 direct dark matter experiment aims to detect the energy of recoiling argon atoms due to the elastic scattering of postulated WIMPs. In order to make such a discovery, a clear understanding of both the background and signal region is essential. This understanding requires a careful study of the detector's response to radioactive sources, which in turn requires such sources may be safely introduced into or near the detector volume and reliably removed. The CALibration Insertaion System (CALIS) was designed and built for this purpose in a joint effort between Fermi National Laboratory and the University of Hawaii. This work describes the design and testing of CALIS, its installation and commissioning at the Laboratori Nazionali del Gran Sasso (LNGS) and the multiple calibration campaigns which have successfully employed it. As nuclear recoils produced by WIMPs are indistinguishable from those produced by neutrons, radiogenic neutrons are both the most dangerous class of background and a vital calibration source for the study of the potential WIMP signal. Prior to the calibration of DarkSide-50 with radioactive neutron sources, the acceptance region was determined by the extrapolation of nuclear recoil data from a separate, dedicated experiment, ScENE, which measured the distribution of the pulse shape discrimination parameter, f 90, for nuclear recoils of known energies. This work demonstrates the validity of the extrapolation of ScENE values to DarkSide-50, by direct comparison of the f90 distribution of nuclear recoils from Sc
Correlations between the nuclear matter symmetry energy, its slope, and curvature
International Nuclear Information System (INIS)
Santos, B M; Delfino, A; Dutra, M; Lourenço, O
2015-01-01
By using point-coupling versions of finite range nuclear relativistic mean field models containing cubic and quartic self interactionsin the scalar field σ, a nonrelativistic limit is achieved. This approach allows for an analytical expression for the symmetry energy (J) as a function of its slope (L) in a unified form, namely, L = 3J + f(m*, ρ o , B o , K o ), where the quantities m*, p o , B o and K o are bulk parameters at the nuclear matter saturation density ρ o . This result establishes a linear correlation between L and J which is reinforced by exact relativistic calculations we have performed. An analogous analytical correlation can also be found for J, L and the symmetry energy curvature (K sym ). Based on these results, we propose a graphic constraint in L × J plane which finite range models should satisfy. (paper)
Studying Cold Nuclear Matter with the MPC-EX of PHENIX
Grau, Nathan; Phenix Collaboration
2017-09-01
Highly asymmetric collision systems, such as d+Au, provide a unique environment to study cold nuclear matter. Potential measurements range from pinning down the modification of the nuclear wave function, i.e. saturation, to studying final state interactions, i.e. energy loss. The PHENIX experiment has enhanced the muon piston calorimeter (MPC) with a silicon-tungsten preshower, the MPC-EX. With its fine segmentation the MPC-EX extends the photon detection capability at 3 < | η | < 3.8. In this talk we review the current status of the detector, its calibration, and its identification capabilities using the 2016 d+Au dataset. We also discuss the specific physics observables the MPC-EX can measure.
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.)
Low mass dielectrons radiated off cold nuclear matter measured with HADES
Directory of Open Access Journals (Sweden)
Lorenz M.
2014-03-01
Full Text Available The High Acceptance DiElectron Spectrometer HADES [1] is installed at the Helmholtzzentrum für Schwerionenforschung (GSI accelerator facility in Darmstadt. It investigates dielectron emission and strangeness production in the 1-3 AGeV regime. A recent experiment series focusses on medium-modifications of light vector mesons in cold nuclear matter. In two runs, p+p and p+Nb reactions were investigated at 3.5 GeV beam energy; about 9·109 events have been registered. In contrast to other experiments the high acceptance of the HADES allows for a detailed analysis of electron pairs with low momenta relative to nuclear matter, where modifications of the spectral functions of vector mesons are predicted to be most prominent. Comparing these low momentum electron pairs to the reference measurement in the elementary p+p reaction, we find in fact a strong modification of the spectral distribution in the whole vector meson region.
Properties of nuclear and neutron matter in a relativistic Hartree-Fock theory
International Nuclear Information System (INIS)
Horowitz, C.J.; Serot, B.D.
1983-01-01
Relativistic-Hartree-Fock (HF) equations are derived for an infinite system of mesons and baryons in the framework of a renormalizable relativistic quantum field theory. The derivation is based on a diagrammatic approach and Dyson's equation for the baryon propagator. The result is a set of coupled, nonlinear integral equations for the baryon self-energy with a self-consistency condition on the single-particle spectrum. The HF equations are solved for nuclear and neutron matter in the Walecka model, which contains neutral scalar and vector mesons. After renormalizing model parameters to reproduce nuclear matter saturation properties, HF results at low to moderate densities are similar to those in the mean-field (Hartree) approximation. Self-consistent exchange corrections to the Hartree equation of state become negligible at high densities. Rho- and pi-meson exchanges are incorporated using a renormalizable gauge-theory model. A chiral transformation of the lagrangian is used to replace the pseudoscalar πN coupling with a pseudovector coupling, for which one-pion exchange is a reasonable first approximation. This transformation maintains the model's renormalizability so that corrections may be evaluated. Pion exchange has a small effect on the HF results of the Walecka model and brings HF results in closer in closer agreement with the mean-field theory. The diagrammatic techniques used here retain the mesonic degrees of freedom and are simple enough to be extended to more refined self-consistent approximations. (orig.)
Hot nuclear matter in the modified quark-meson coupling model with quark-quark correlations
International Nuclear Information System (INIS)
Zakout, I.; Jaqaman, H.R.
2000-01-01
Short-range quark-quark correlations in hot nuclear matter are examined within the modified quark-meson coupling (MQMC) model by adding repulsive scalar and vector quark-quark interactions. Without these correlations, the bag radius increases with the baryon density. However, when the correlations are introduced the bag size shrinks as the bags overlap. Also as the strength of the scalar quark-quark correlation is increased, the decrease of the effective nucleon mass M* N with the baryonic density is slowed down and tends to saturate at high densities. Within this model we study the phase transition from the baryon-meson phase to the quark-gluon plasma (QGP) phase with the latter modelled as an ideal gas of quarks and gluons inside a bag. Two models for the QGP bag parameter are considered. In one case, the bag is taken to be medium-independent and the phase transition from the hadron phase to QGP is found to occur at five to eight times ordinary nuclear matter density for temperatures less than 60 MeV. For lower densities, the transition takes place at a higher temperature, reaching up to 130 MeV at zero density. In the second case, the QGP bag parameter is considered to be medium-dependent as in the MQMC model for the hadronic phase. In this case, it is found that the phase transition occurs at much lower densities. (author)
Chae, Jinho; Choi, Hyun Woo; Lee, Woo Jin; Kim, Dongsung; Lee, Jae Hac
2008-07-01
Impingement of a large amount of gelatinous plankton, Salpa fusiformis on the seawater intake system-screens in a nuclear power plant at Uljin was firstly recorded on 18th June 2003. Whole amount of the clogged animals was estimated were presumptively at 295 tons and the shortage of cooling seawater supply by the animal clogging caused 38% of decrease in generation capability of the power plant. Zooplankton collection with a multiple towing net during the day and at night from 5 to 6 June 2003 included various gelatinous zooplanktons known to be warm water species such as salps and siphonophores. Comparatively larger species, Salpa fusiformis occupied 25.4% in individual density among the gelatinous plankton and showed surface distribution in the depth shallower than thermocline, performing little diel vertical migration. Temperature, salinity and satellite data also showed warm surface current predominated over the southern coastal region near the power plant in June. The results suggested that warm surface current occasionally extended into the neritic region may transfer S. fusiformis, to the waters off the power plant. The environmental factors and their relation to ecobiology of the large quantity of salpa population that are being sucked into the intake channel of the power plant are discussed.
Exploring the Quark-Gluon Content of Hadrons: From Mesons to Nuclear Matter
International Nuclear Information System (INIS)
Hrayr Matevosyan
2007-01-01
Even though Quantum Chromodynamics (QCD) was formulated over three decades ago, it poses enormous challenges for describing the properties of hadrons from the underlying quark-gluon degrees of freedom. Moreover, the problem of describing the nuclear force from its quark-gluon origin is still open. While a direct solution of QCD to describe the hadrons and nuclear force is not possible at this time, we explore a variety of developed approaches ranging from phenomenology to first principle calculations at one or other level of approximation in linking the nuclear force to QCD. The Dyson Schwinger formulation (DSE) of coupled integral equations for the QCD Green's functions allows a non-perturbative approach to describe hadronic properties, starting from the level of QCD n-point functions. A significant approximation in this method is the employment of a finite truncation of the system of DSEs, that might distort the physical picture. In this work we explore the effects of including a more complete truncation of the quark-gluon vertex function on the resulting solutions for the quark 2-point functions as well as the pseudoscalar and vector meson masses. The exploration showed strong indications of possibly large contributions from the explicit inclusion of the gluon 3- and 4-point functions that are omitted in this and previous analyses. We then explore the possibility of extrapolating state of the art lattice QCD calculations of nucleon form factors to the physical regime using phenomenological models of nucleon structure. Finally, we further developed the Quark Meson Coupling model for describing atomic nuclei and nuclear matter, where the quark-gluon structure of nucleons is modeled by the MIT bag model and the nucleon many body interaction is mediated by the exchange of scalar and vector mesons. This approach allows us to formulate a fully relativistic theory, which can be expanded in the nonrelativistic limit to reproduce the well known phenomenological Skyrme
Meson production in nuclear collisions and the equation of state of hadronic matter
International Nuclear Information System (INIS)
Grosse, E.
1993-01-01
Whereas nuclear matter at saturation, i.e. at its ground state density [ρ o ≅ 1 nucleon per 6 fm 3 ] is realized in the center of nuclei, it is compressed to much higher density in neutron stars and during explosive stellar processes like novae and supernovae. The hard core repulsion in the nucleon-nucleon potential and also the Pauli principle counteract such a compression and the stiffness of the equation of state of this matter is determined by these two effects - at least up to a certain density. For very high density and temperature it is believed that the nucleons dissociate into a plasma of quarks and gluons. On the other hand there are detailed theoretical arguments and also experimental evidence shown here, that in the intermediate density range the equation of state is influenced by a different scenario. The conversion of nucleons into heavier baryons leads directly to an additional mass density and at the same time their different quantum numbers allow a higher particle number in a given volume of phase space. The heavy baryons in question are nucleon resonances (Δ,N*) and to smaller extent also hyperons; to conserve strangeness the formation of the latter is associated with the production of kaons whereas Δ's and N*'s are strongly coupled to the pions in the hadronic matter in the collision zone. (author)
Energy Technology Data Exchange (ETDEWEB)
Typel, S; Wolter, H H [Sektion Physik, Univ. Muenchen, Garching (Germany)
1998-06-01
Nuclear matter and ground state properties for (proton and neutron) semi-closed shell nuclei are described in relativistic mean field theory with coupling constants which depend on the vector density. The parametrization of the density dependence for {sigma}-, {omega}- and {rho}-mesons is obtained by fitting to properties of nuclear matter and some finite nuclei. The equation of state for symmetric and asymmetric nuclear matter is discussed. Finite nuclei are described in Hartree approximation, including a charge and an improved center-of-mass correction. Pairing is considered in the BCS approximation. Special attention is directed to the predictions for properties at the neutron and proton driplines, e.g. for separation energies, spin-orbit splittings and density distributions. (orig.)
Chiral approach to nuclear matter: Role of two-pion exchange with virtual delta-isobar excitation
Fritsch, S.; Kaiser, N.; Weise, W.
2004-01-01
We extend a recent three-loop calculation of nuclear matter in chiral perturbation theory by including the effects from two-pion exchange with single and double virtual $\\Delta(1232)$-isobar excitation. Regularization dependent short-range contributions from pion-loops are encoded in a few NN-contact coupling constants. The empirical saturation point of isospin-symmetric nuclear matter, $\\bar E_0 = -16 $MeV, $\\rho_0 = 0.16 $fm$^{-3}$, can be well reproduced by adjusting the strength of a two-...
International Nuclear Information System (INIS)
Anon.
1992-01-01
Canada's Green Plan strategy for dealing with global warming is being implemented as a multidepartmental partnership involving all Canadians and the international community. Many of the elements of this strategy are built on an existing base of activities predating the Green Plan. Elements of the strategy include programs to limit emissions of greenhouse gases, such as initiatives to encourage more energy-efficient practices and development of alternate fuel sources; studies and policy developments to help Canadians prepare and adapt to climate change; research on the global warming phenomenon; and stimulation of international action on global warming, including obligations arising out of the Framework Convention on Climate Change. All the program elements have been approved, funded, and announced. Major achievements to date are summarized, including improvements in the Energy Efficiency Act, studies on the socioeconomic impacts of global warming, and participation in monitoring networks. Milestones associated with the remaining global warming initiatives are listed
Energy Technology Data Exchange (ETDEWEB)
Brygoo, St
2006-11-15
The purpose of this work was to develop a new approach of laser shocks on pre-compressed targets in order to collect data concerning the equation of state in the warm dense matter zone of the phase diagram. The accuracy of the measurement has been increased by the use of a new metrology based on quartz. Quartz is considered as a standard for the measurement of both the pressure and the density, a model of an isentropic relaxation based on a Grueneisen type approximation has been developed. By combining laser shocks with diamond anvil cells and by using this new metrology, we have investigated the following systems: diamond, helium, hydrogen, deuterium and hydrogen-helium mixtures. The results for helium agree very well with the predictions of the Saumon-Chabrier model. The results for deuterium are consistent with the latest results found in literature. As for the results concerning hydrogen, they have showed the limits of the quartz-based metrology. In fact, by being so little dense we are at the limit of the application range of the quartz relaxation. A mixture of helium-hydrogen (50 %) has been investigated, no sign of phase separation has been found.
Measurement of Nuclear Recoils in the CDMS II Dark Matter Search
Fallows, Scott M.
The Cryogenic Dark Matter Search (CDMS) experiment is designed to directly detect elastic scatters of weakly-interacting massive dark matter particles (WIMPs), on target nuclei in semiconductor crystals composed of Si and Ge. These scatters would occur very rarely, in an overwhelming background composed primarily of electron recoils from photons and electrons, as well as a smaller but non-negligible background of WIMP-like nuclear recoils from neutrons. The CDMS~II generation of detectors simultaneously measure ionization and athermal phonon signals from each scatter, allowing discrimination against virtually all electron recoils in the detector bulk. Pulse-shape timing analysis allows discrimination against nearly all remaining electron recoils taking place near detector surfaces. Along with carefully limited neutron backgrounds, this experimental program allowed for "background-free'' operation of CDMS~II at Soudan, with less than one background event expected in each WIMP-search analysis. As a result, exclusionary upper-limits on WIMP-nucleon interaction cross section were placed over a wide range of candidate WIMP masses, ruling out large new regions of parameter space. These results, like any others, are subject to a variety of systematic effects that may alter their final interpretations. A primary focus of this dissertation will be difficulties in precisely calibrating the energy scale for nuclear recoil events like those from WIMPs. Nuclear recoils have suppressed ionization signals relative to electron recoils of the same recoil energy, so the response of the detectors is calibrated differently for each recoil type. The overall normalization and linearity of the energy scale for electron recoils in CDMS~II detectors is clearly established by peaks of known gamma energy in the ionization spectrum of calibration data from a 133Ba source. This electron-equivalent keVee) energy scale enables calibration of the total phonon signal (keVt) by enforcing unity
International Nuclear Information System (INIS)
Blasche, K.; Bock, R.; Franzke, B.; Greiner, W.; Gutbrod, H.H.; Povh, B.; Schmelzer, C.; Stock, R.
1977-01-01
The future problems of heavy-ion physics in the 10 GeV/U range are dealt with: the dynamics of relativistic nuclear collisions, phase transitions, nuclear matter, quantum electrodynamics of extremely strong fields, and astrophysical aspects. In the second part, the project of a heavy-ion accelerator in the 10 GeV/U range to be coupled to the present GSI UNILAC accelerator is discussed. (WL) [de
International Nuclear Information System (INIS)
Li Baoan; Chen Liewen; Wen Dehua; Xiao Zhigang; Xu Chang; Yong Gaochan; Zhang Ming
2010-01-01
The nuclear symmetry energy E sym (ρ) is the most uncertain part of the Equation of State (EOS) of dense neutron-rich nuclear matter. In this talk, we discuss the underlying physics responsible for the uncertain E sym (ρ) especially at supra-saturation densities, the circumstantial evidence for a super-soft E sym (ρ) from analyzing π - /π + ratio in relativistic heavy-ion collisions and its impacts on astrophysics and cosmology.
Squeeze-out of nuclear matter as a function of projectile energy and mass
International Nuclear Information System (INIS)
Gutbrod, H.H.; Kampert, K.H.; Kolb, B.; Poskanzer, A.M.; Ritter, H.G.; Schicker, R.; Schmidt, H.R.
1990-01-01
Squeeze-out, a component of the collective flow of nuclear matter, is the preferential emission of particles out of the reaction plane. Using the sphericity method the out-of-plane/in-plane ratio of the kinetic energy flow has been analyzed as a function of multiplicity and beam energy for Ca+Ca, Nb+Nb, and Au+Au collisions measured with the Plastic Ball detector at the Bevalac. Also, azimuthal distribution of the particles around the flow axis are presented together with the extracted out-of-plane/in-plane ratios. Finally, the rapidity dependence of the out-of-plane/in-plane ratio has been investigated with a new method using the transverse momentum components of the particles
Surface behaviour of the pairing gap in a slab of nuclear matter
International Nuclear Information System (INIS)
Baldo, M.; Farine, M.; Lombardo, U.; Saperstein, E.E.; Zverev, M.V.; Schuck, P.
2003-01-01
The surface behavior of the pairing gap previously studied for semi-infinite nuclear matter is analyzed in the slab geometry. The gap-shape function is calculated in two cases: a) pairing with the Gogny force in a hard-wall potential and b) pairing with the separable Paris interaction in a Saxon-Woods mean-field potential. It is shown that the surface features are preserved in the case of slab geometry, being almost independent of the width of the slab. It is also demonstrated that the surface enhancement is strengthened as the absolute value of chemical potential vertical stroke μvertical stroke decreases which simulates the approach to the nucleon drip line. (orig.)
Phase diagram of dilute nuclear matter: Unconventional pairing and the BCS-BEC crossover
Energy Technology Data Exchange (ETDEWEB)
Stein, Martin; Sedrakian, Armen [Frankfurt Univ. (Germany). Inst. fuer Theoretische Physik
2013-07-01
We report on a comprehensive study of the phase structure of cold, dilute nuclear matter featuring a {sup 3}S{sub 1}-{sup 3}D{sub 1} condensate at non-zero isospin asymmetry, within wide ranges of temperatures and densities. We find a rich phase diagram comprising three superfluid phases, namely a LOFF phase, the ordinary BCS phase, and a heterogeneous, phase-separated BCS phase, with associated crossovers from the latter two phases to a homogeneous or phase-separated Bose-Einstein condensate of deuterons. The phase diagram contains two tri-critical points (one a Lifshitz point), which may degenerate into a single tetra-critical point for some degree of isospin asymmetry.
Correlation effects on the nonmesonic weak decay of the Λ hyperon in nuclear matter
Robertson, N. J.; Dickhoff, W. H.
2005-08-01
The nonmesonic weak decay of a Λ hyperon is studied in nuclear matter. Special emphasis is placed on a consistent treatment of correlations introduced by the strong interaction on its weak counterpart. The latter is described by the exchange of mesons between the initial ΛN state and the final NN one. The weak decay is studied in terms of the weak self-energy, which allows a systematic evaluation of short-range and tensor correlation effects that are determined by a realistic hyperon-nucleon interaction. The admixture of ΣN components through the strong interaction is also included in the calculation of the Λ decay properties. Calculations for the ratio of the neutron-induced partial width to the corresponding proton-induced one, Γn/Γp, are discussed in connection with recent experimental results.
Toward the Limits of Matter: Ultra-relativistic nuclear collisions at CERN
Schukraft, Jurgen
2015-01-01
Strongly interacting matter as described by the thermodynamics of QCD undergoes a phase transition, from a low temperature hadronic medium to a high temperature quark-gluon plasma state. In the early universe this transition occurred during the early microsecond era. It can be investigated in the laboratory, in collisions of nuclei at relativistic energy, which create "fireballs" of sufficient energy density to cross the QCD Phase boundary. We describe 3 decades of work at CERN, devoted to the study of the QCD plasma and the phase transition. From modest beginnings at the SPS, ultra-relativistic heavy ion physics has evolved today into a central pillar of contemporary nuclear physics and forms a significant part of the LHC program.
Non-Markovian effects on the dynamics of bubble growth in hot asymmetric nuclear matter
International Nuclear Information System (INIS)
Kolomietz, V.M.; Sanzhur, A.I.; Shlomo, S.
2003-01-01
We study the conditions for the generation and the dynamical evolution of embryonic overcritical vapor bubbles in an overheated asymmetric nuclear matter. We show that the Fermi-surface distortion and memory effects significantly hinder the growth of the bubbles. Moreover, the growth of the bubble is accompanied by characteristic oscillations of its radius R. The characteristic energy E, the damping parameter Γ, and the instability growth rate parameter ζ, depend on the relaxation time τ. The characteristic oscillations disappear in the short relaxation time limit τ→0. Our approach ignores the fluctuations of the particle numbers in the bubble region and the finite diffuse layer of the bubble. The minimum size of the critical radius R * for which our approach applies is determined by the condition a/R * <<1, where a=0.5-1 fm is the temperature-dependent surface thickness of the bubble
Effective mass of a #betta#-particle in nuclear matter and OBE #betta#-n interactions
International Nuclear Information System (INIS)
Bando, Hiroharu; Nagata, Sinobu.
1982-01-01
The effective mass of a lambda particle (M sub( lambda )*) in nuclear matter is investigated within the framework of the lowest-order Brueckner theory by employing the Nijmegen OBE lambda -N interaction model D and F. The non-locality mass (M tilde sub( lamda )) and the energy mass (anti M sub( lambda )) are evaluated and discussed in the light of the characteristics of the two models. In comparison with the model D, the model F yields smaller anti M sub( lambda ) and larger anti M sub( lamb da ) reflecting the stronger Majorana exchange force and the stronger lambda N- sigma N coupling tensor force. Final results of M sub( lambda )*/M sub( lambda ) are 0.85 for D and 0.79 for F. In view of the effective lambda mass inferred from observed properties of the single particle potential for lambda , the model D interaction seems to be more adequate. (author)
Low mass dilepton production at the SPS probing hot and dense nuclear matter
Pérez de los Heros, C; Baur, R; Breskin, Amos; Chechik, R; Drees, A; Jacob, C; Faschingbauer, U; Fisher, P H; Fraenkel, Zeev; Fuchs, C; Gatti, E; Glässel, P; Günzel, T F; Hess, F; Irmscher, D; Lenkeit, B C; Olsen, L H; Panebratsev, Yu A; Pfeiffer, A; Ravinovich, I; Rehak, P; Schön, A; Schükraft, Jürgen; Sampietro, M; Shimansky, S S; Shor, A; Specht, H J; Steiner, V; Tapprogge, Stefan; Tel-Zur, G; Tserruya, Itzhak; Ullrich, T S; Wurm, J P; Yurevich, V I
1996-01-01
CERES and HELIOS-3 have detected a significant enhancement of low--mass dileptons in nuclear collisions at 200 GeV/nucleon with respect to the expected ``conventional'' sources. The onset of the excess, starting at a mass of $\\sim2m_{\\pi}$, and the possibility of a quadratic dependence on the event multiplicity suggest the opening of the $\\pi^+\\pi^-\\rightarrow e^+e^-(\\mu^+\\mu^-)$ annihilation channel. This would be the first observation of thermal radiation from dense hadronic matter. Possible interpretations of these results are presented, including the reduction of the $\\rho$ mass due to partial restoration of chiral symmetry in the dense fireball formed in the collision.
Effects of isospin and momentum-dependent interactions on thermal properties of nuclear matter
International Nuclear Information System (INIS)
Xu Jun; Ma Hongru; Chen Liewen; Li Baoan
2009-01-01
In this article, three models with different isospin and momentum dependence are used to study the thermodynamical properties of asymmetric nuclear matter. They are isospin and momentum-dependent MDI interaction constrained by the isospin diffusion data of heavy ion collision, the momentum-independent MID interaction and the isoscalar momentum-dependent eMDYI interaction. Temperature effects of symmetry energy, mechanical and chemical instability and liquid-gas phase transition are analyzed. It is found that for MDI model the temperature effects of the symmetry energy attribute from both the kinetic and potential energy, while only potential part contributes to the decreasing of the symmetry energy for MID and eMDYI models. We also find that the mechanical instability, chemical instability and liquid-gas phase transition are all sensitive to the isospin and momentum dependence and the density dependence of the symmetry energy. (authors)
International Nuclear Information System (INIS)
2011-01-01
While maintaining a strong industry in France is agreed by the vast majority, it appears irresponsible to advocate the phasing-out of nuclear energy in the French territory. Nuclear energy is undoubtedly France's best competitive advantage. The Concorde foundation recommends to avoid any change in France's energy mix which would have a significant impact on French citizens' standard of living
New relativistic effective interaction for finite nuclei, infinite nuclear matter, and neutron stars
Kumar, Bharat; Patra, S. K.; Agrawal, B. K.
2018-04-01
We carry out the study of finite nuclei, infinite nuclear matter, and neutron star properties with the newly developed relativistic force, the Institute of Physics Bhubaneswar-I (IOPB-I). Using this force, we calculate the binding energies, charge radii, and neutron-skin thickness for some selected nuclei. From the ground-state properties of superheavy nuclei (Z =120 ), it is noticed that considerable shell gaps appear at neutron numbers N =172 , 184, and 198, manifesting the magicity at these numbers. The low-density behavior of the equation of state for pure neutron matter is compatible with other microscopic models. Along with the nuclear symmetry energy, its slope and curvature parameters at the saturation density are consistent with those extracted from various experimental data. We calculate the neutron star properties with the equation of state composed of nucleons and leptons in β -equilibrium, which are in good agreement with the x-ray observations by Steiner [Astrophys. J. 722, 33 (2010), 10.1088/0004-637X/722/1/33] and Nättilä [Astron. Astrophys. 591, A25 (2016), 10.1051/0004-6361/201527416]. Based on the recent observation of GW170817 with a quasi-universal relation, Rezzolla et al. [Astrophys. J. Lett. 852, L25 (2018), 10.3847/2041-8213/aaa401] have set a limit for the maximum mass that can be supported against gravity by a nonrotating neutron star in the range 2.01 ±0.04 ≲M (M⊙)≲2.16 ±0.03 . We find that the maximum mass of the neutron star for the IOPB-I parametrization is 2.15 M⊙ . The radius and tidal deformability of a canonical neutron star of mass 1.4 M⊙ are 13.2 km and 3.9 ×1036g cm2s2 , respectively.
Thermodynamic coupling of heat and matter flows in near-field regions of nuclear waste repositories
International Nuclear Information System (INIS)
Carnahan, C.L.
1983-11-01
In near-field regions of nuclear waste repositories, thermodynamically coupled flows of heat and matter can occur in addition to the independent flows in the presence of gradients of temperature, hydraulic potential, and composition. The following coupled effects can occur: thermal osmosis, thermal diffusion, chemical osmosis, thermal filtration, diffusion thermal effect, ultrafiltration, and coupled diffusion. Flows of heat and matter associated with these effects can modify the flows predictable from the direct effects, which are expressed by Fourier's law, Darcy's law, and Fick's law. The coupled effects can be treated quantitatively together with the direct effects by the methods of the thermodynamics of irreversible processes. The extent of departure of fully coupled flows from predictions based only on consideration of direct effects depends on the strengths of the gradients driving flows, and may be significant at early times in backfills and in near-field geologic environments of repositories. Approximate calculations using data from the literature and reasonable assumptions of repository conditions indicate that thermal-osmotic and chemical-osmotic flows of water in semipermeable backfills may exceed Darcian flows by two to three orders of magnitude, while flows of solutes may be reduced greatly by ultrafiltration and chemical osmosis, relative to the flows predicted by advection and diffusion alone. In permeable materials, thermal diffusion may contribute to solute flows to a smaller, but still significant, extent
Measurement of Nuclear Recoils in the CDMS II Dark Matter Search
Energy Technology Data Exchange (ETDEWEB)
Fallows, Scott Mathew [Univ. of Minnesota, Minneapolis, MN (United States)
2014-12-01
The Cryogenic Dark Matter Search (CDMS) experiment is designed to directly detect elastic scatters of weakly-interacting massive dark matter particles (WIMPs), on target nuclei in semiconductor crystals composed of Si and Ge. These scatters would occur very rarely, in an overwhelming background composed primarily of electron recoils from photons and electrons, as well as a smaller but non-negligible background of WIMP-like nuclear recoils from neutrons. The CDMS II generation of detectors simultaneously measure ionization and athermal phonon signals from each scatter, allowing discrimination against virtually all electron recoils in the detector bulk. Pulse-shape timing analysis allows discrimination against nearly all remaining electron recoils taking place near detector surfaces. Along with carefully limited neutron backgrounds, this experimental program allowed for \\background- free" operation of CDMS II at Soudan, with less than one background event expected in each WIMP-search analysis. As a result, exclusionary upper-limits on WIMP-nucleon interaction cross section were placed over a wide range of candidate WIMP masses, ruling out large new regions of parameter space.
Energy Technology Data Exchange (ETDEWEB)
Margueron, J
2001-07-01
We study the elementary interactions between neutrinos and dense matter in a proto-neutron star. Equations of state obtained with different nuclear effective interactions (Skyrme, Gogny, Relativistic Lagrangians) are first discussed. Then, we characterize their stability in spin and isospin. We derive magnetic susceptibilities for all isospin asymmetry values as a function of Landau parameters G{sup {pi}}{sup {pi}}{sup '}{sub 0} (where {pi}, {pi}' = proton or neutron). From this work, we select a parametrization for each of the 3 effective forces: Sly230b,D1P,NL3. We calculate the pure neutron matter and asymmetric nuclear matter response functions with and without charge exchange, describing nuclear correlations in both approaches: non-relativistic (Hartree-Fock with Skyrme forces, then complete RPA) and relativistic (in the Hartree approximation). At the end, we calculate neutrino mean free paths neutral current and charged current reactions. Comparisons between relativistic and non-relativistic approaches allow us to identify relativistic effects in nuclear matter at densities as low as twice the saturation density. RPA correlations make the medium more transparent to neutrinos compared to free Fermi gas. The importance of the effective mass in mean free path calculations is also shown. (author)
Energy Technology Data Exchange (ETDEWEB)
Matsuzaki, M. [Fukuoka Univ. of Education, Dept. of Physics, Munakata, Fukuoka (Japan); Tanigawa, T.
1999-08-01
We propose a simple method to reproduce the {sup 1}S{sub 0} pairing properties of nuclear matter, which are obtained by a sophisticated model, by introducing a density-independent cutoff into the relativistic mean field model. This applies well to the physically relevant density range. (author)
International Nuclear Information System (INIS)
Gubler, Philipp; Ohtani, Keisuke
2015-01-01
The modification of the ϕ-meson at finite density is studied by using QCD sum rules in combination with the maximum entropy method. As a result, it is found that the mass shift of the ϕ-meson is strongly correlated to the strangeness content of the nucleon, , which governs the depletion of the strange quark condensate in nuclear matter. (author)
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
International Nuclear Information System (INIS)
Aoki, Shinya
2011-01-01
Four main research subjects in the strategic field No. 5 'The origin of matter and the universe', planned to be investigated on 'Kei' super computer, are explained in detail, by focusing on interdisciplinary aspect of researches among particle, nuclear and astrophysics. (author)
2013-05-17
... and DPR-48] In the Matter of Zion Solutions, LLC; Zion Nuclear Power Station, Units 1 and 2; Order... formed for the purpose of acquiring ES, Inc. and is held by certain investment fund entities organized by... Environmental Management Programs, in writing, of such receipt no later than one (1) business day prior to the...
International Nuclear Information System (INIS)
Hayashi, Taizo
2005-01-01
The future structure surrounding fuel choice in power generation sector should be understood how to evaluate actual and potential merit and demerit both in economic and environmental aspects on nuclear power generation. That is i.e. nuclear can be understood as superior power source without GHGs and on the other hand, as unfavorable power source which might cause some critical dangers due to its hazardous radioactive nuclear waste. On this specific characteristic, this theme on fuel choice surrounding nuclear in power generation sector could be understood as a highly cultural problem as much as economic and political one. For instance, we can observe quite opposite direction with each other on nuclear power development in European countries like France and Finland on one hand and Germany and Sweden on the other hand. Looking at Asian countries, we also observe the very reality of high economic growth with rapid growth of electricity demand like China. What on earth, is it really possible without nuclear power source for such gigantic countries. I will develop my personal idea on nuclear power source based on Japanese experience towards successfully managing nuclear power technologies in the world, consisting of developing countries with growing economies and of advanced ones with rather matured nuclear technology under the pressure of environmentally restricted world order. My basic view point to discuss nuclear power problem has, conclusionally speaking, several aspects; The first one is in the relation with deregulation or liberalization of electricity market, which has been undergoing among such developed countries as OECD member countries i.e. USA, EU, Japan and other countries. Deregulation or liberalization of electricity market seems to be the inevitable process towards more matured market economy among developed countries group, and that process inevitably forces management of power companies towards more near sighted attitude if those companies are
Nucleonics, and nuclear matter in 10-20 secs. before the close of open-quotes Big Bangclose quotes
International Nuclear Information System (INIS)
Ayub, S.M.
1995-01-01
The Nuclear picture 10 -20 secs. after the thermonuclear creation of the Universe ∼8 Billion years ago (as also evidenced by Hubble Telescope) was published. Relativity concepts predict the Nuclear picture l0 -20 secs. before the open-quote G close-quote collapse of the Universe, by the progressive decline of expansion,and H. Constant. No double-nuclei, anymore. Only Neutrinos, as predicted by International Scientists, and fragments of Black Holes. Universe open-quote r close-quote=60 Billion Light-Years. At the Zero Point, N.Force,and 3 other Forces merging into Super-G. Time, Space, becoming identical, and all Physical Laws vanishing. The final will be Nuclear Matter compact of ∼ 10Km., open-quote r close-quote, P=10 15 -10 18 Temp. > 10 10 Deg. C. P> 10 18 will cause another thermonuclear Bang'. Super-computers, also, cannot predict beyond this point. There will be the Creator, and a compact of Nuclear Matter. In the absence of Physical Laws, there can be no further predictability. What initiated by the N. Force, has culminated into a compact of Nuclear Matter- - how interesting exclamation point
International Nuclear Information System (INIS)
Kato, Yoshinobu; Fujita, Yusuke
2005-01-01
At the Awara campus (lat. 36.264degN, long, 136.235degE) of Fukui University of Technology, a Terra/Aqua-MODIS receiving system is operated from September, 2003. This paper deals with the thermal band image processing by using the received MODIS data. In chapter 2, we investigate the image representation of the warm water discharges of nuclear power plants located with Wakasa Bay of Fukui Prefecture. In chapter 3, we describe the image processing of the drifting of Echizen-Jellyfishes. The Echizen-Jellyfish, a kind of big jellyfish, whose scientific name is Nemopilema nomurai Kishinouye, appeared in large quantities in 2003 and did serious damage to the fishery in Japan Sea. (author)
Properties of ΣQ*, ΞQ* and ΩQ* heavy baryons in cold nuclear matter
Azizi, K.; Er, N.
2018-02-01
The in-medium properties of the heavy spin-3/2 ΣQ*, ΞQ* and ΩQ* baryons with Q being b or c quark are investigated. The shifts in some spectroscopic parameters of these particles due to the saturated cold nuclear matter are calculated. The variations of those parameters with respect to the changes in the density of the cold nuclear medium are studied, as well. It is observed that the parameters of ΣQ* baryons are considerably affected by the nuclear matter compared to the ΞQ* and ΩQ* particles that roughly do not see the medium. The results obtained may be used in analyses of the data to be provided by the in-medium experiments like PANDA.