Download or read book Nuclear Level Densities Proceedings Of The Oecd Meeting written by G Reffo and published by World Scientific. This book was released on 1992-05-30 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume collects the papers presented at the “Specialists' Meeting on Nuclear Level Densities”, held in Bologna 15 - 17 November, 1989, which gathered most of the scientists working in the field. The papers cover all the major aspects of the level density problem both from the theoretical and the experimental viewpoint, including the subject of partial level densities. In particular, moment method, collective vector method, interacting boson model, static path approximation and combinatorial approach are discussed. Effects of the residual interactions and nuclear structure are also addressed, giving a state-of-art reveiw of our present knowledge on nuclear level densities.
Download or read book Studies of Low energy Nuclear Reactions and Level Densities for Medium mass Nuclei written by Anastasios A. Katsanos and published by . This book was released on 1967 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Level Densities in Nuclear Physics written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the independent-particle model nucleons move independently in a central potential. There is a well-defined set of single- particle orbitals, each nucleon occupies one of these orbitals subject to Fermi statistics, and the total energy of the nucleus is equal to the sum of the energies of the individual nucleons. The basic question is the range of validity of this Fermi gas description and, in particular, the roles of the residual interactions and collective modes. A detailed examination of experimental level densities in light-mass system is given to provide some insight into these questions. Level densities over the first 10 MeV or so in excitation energy as deduced from neutron and proton resonances data and from spectra of low-lying bound levels are discussed. To exhibit some of the salient features of these data comparisons to independent-particle (shell) model calculations are presented. Shell structure is predicted to manifest itself through discontinuities in the single-particle level density at the Fermi energy and through variatons in the occupancy of the valence orbitals. These predictions are examined through combinatorial calculations performed with the Grover (Phys. Rev., 157, 832(1967), 185 1303(1969)) odometer method. Before the discussion of the experimenta results, statistical mechanical level densities for spherical nuclei are reviewed. After consideration of deformed nuclei, the conclusions resulting from this work are drawn. 7 figures, 3 tables. (RWR).
Download or read book On the Statistical Calculation of the Density of the Energy Levels of the Nuclei written by C. Van Lier and published by . This book was released on 1937 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Foundations of High Energy Density Physics written by Jon Larsen and published by Cambridge University Press. This book was released on 2017-03-10 with total page 759 pages. Available in PDF, EPUB and Kindle. Book excerpt: A valuable and complete resource that brings together many of the branches of physics needed in high-energy-density physics. Targeted at research scientists and graduate students in physics and astrophysics, this book begins with basic concepts and develops a detailed explanation of the physics of hydrodynamics and energy transport in plasma.
Download or read book Chaos and Structure of Level Densities written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The energy region of the first few MeV above the ground state shows interesting features of the nucleus. Beyond an ordered energy region just above the ground-state the dynamics changes, and chaotic features are observed in the neutron resonance region. The statistical properties of energies and wave-functions are common to all chaotic nuclei. However, if instead a global property, like the local level-density function is studied, strong structure effects emerge. In this contribution we discuss these two different facets of warm nuclei. In section 2 the onset of chaos with increasing excitation energy is discussed, with both experimental observations and proposed theoretical mechanisms as starting points. The structure of level densities in the same excitation energy region based on the two different starting points, is treated in section 3, where we give a short presentation of a newly developed combinatorial level-density modell. Some results from the model are presented and discussed. Two coexisting facets of warm nuclei, quantum chaos and structure of the level density, are considered. A newly developed combinatorial level-density model is presented, and the role of collective enhancements discussed. An example of extreme parity enhancement is shown.
Download or read book Nuclear Level Density written by Fawzeya Gharghar and published by LAP Lambert Academic Publishing. This book was released on 2010-05 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the characteristic properties of a nucleus is the nuclear level (state) density(number of levels (states) per unit energy interval) as a function of excitation energy. A level corresponds to several degenerate states. Nuclear level density is a basic quantity of the nucleus and plays an important role in both pure and applied physics. This importance comes from the wide needs for understanding the nuclear system properties such as the description of excited nuclei, the ssion dynamics and the calculation of reaction cross sections. Given the experimentally observed spectrum of a nucleus in the ground state region, the level density is simply calculated by counting the number of levels (states) in a given energy interval. For heavy nuclei, the excitation energy up to which complete information (all levels measured (energy) and identi ed (angular momentum)) is usually available is around 2 MeV. Further, experimental information in terms of neutron or proton resonances is available at the neutron or proton separation energy. There is no information in the intermediate energy region."
Download or read book The Nuclear Shell Model and Nuclear Level Densities written by Ann Auriol Ross and published by . This book was released on 1956 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Uses of Level Density Models written by and published by . This book was released on 1989 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper addresses issues associated with the use of nuclear level density models in calculations made for data applications. The two most commonly used models, the Gilbert Cameron and the Back-Shifted Fermi Gas, are briefly summarized and examples are provided of recent efforts to improve their parameterization. Calculated particle emission spectra are compared with recent experimental data in order to assess performance and sensitivity to these models. Extrapolation of nuclear level densities for calculations involving nuclei away from stability poses special problems and examples of recent efforts to improve such extrapolations are cited. The sensitivity of current schemes in the modeling of fission transition state densities are explored through calculated (n, f) cross sections. Two newer phenomenological models, those of Ignatyuk and Schmidt, provide a more physically realistic description of level densities. Calculations concerning 2°7Pb(n, xn) cross sections compare results using the Ignatyuk formalism with the Gilbert Cameron results. 31 refs., 10 figs.
Download or read book Random Matrices and the Statistical Theory of Energy Levels written by M. L. Mehta and published by Academic Press. This book was released on 2014-05-12 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Random Matrices and the Statistical Theory of Energy Levels focuses on the processes, methodologies, calculations, and approaches involved in random matrices and the statistical theory of energy levels, including ensembles and density and correlation functions. The publication first elaborates on the joint probability density function for the matrix elements and eigenvalues, including the Gaussian unitary, symplectic, and orthogonal ensembles and time-reversal invariance. The text then examines the Gaussian ensembles, as well as the asymptotic formula for the level density and partition function. The manuscript elaborates on the Brownian motion model, circuit ensembles, correlation functions, thermodynamics, and spacing distribution of circular ensembles. Topics include continuum model for the spacing distribution, thermodynamic quantities, joint probability density function for the eigenvalues, stationary and nonstationary ensembles, and ensemble averages. The publication then examines the joint probability density functions for two nearby spacings and invariance hypothesis and matrix element correlations. The text is a valuable source of data for researchers interested in random matrices and the statistical theory of energy levels.
Download or read book High Energy Density Physics written by R Paul Drake and published by Springer. This book was released on 2018-01-02 with total page 671 pages. Available in PDF, EPUB and Kindle. Book excerpt: The raw numbers of high-energy-density physics are amazing: shock waves at hundreds of km/s (approaching a million km per hour), temperatures of millions of degrees, and pressures that exceed 100 million atmospheres. This title surveys the production of high-energy-density conditions, the fundamental plasma and hydrodynamic models that can describe them and the problem of scaling from the laboratory to the cosmos. Connections to astrophysics are discussed throughout. The book is intended to support coursework in high-energy-density physics, to meet the needs of new researchers in this field, and also to serve as a useful reference on the fundamentals. Specifically the book has been designed to enable academics in physics, astrophysics, applied physics and engineering departments to provide in a single-course, an introduction to fluid mechanics and radiative transfer, with dramatic applications in the field of high-energy-density systems. This second edition includes pedagogic improvements to the presentation throughout and additional material on equations of state, heat waves, and ionization fronts, as well as problem sets accompanied by solutions.
Download or read book Electronic Density of States written by Lawrence Herman Bennett and published by . This book was released on 1971 with total page 842 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Level Densities from Spectra of Different Reactions Populating the Same Nucleus written by and published by . This book was released on 1971 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Frontiers in High Energy Density Physics written by National Research Council and published by National Academies Press. This book was released on 2003-05-11 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent scientific and technical advances have made it possible to create matter in the laboratory under conditions relevant to astrophysical systems such as supernovae and black holes. These advances will also benefit inertial confinement fusion research and the nation's nuclear weapon's program. The report describes the major research facilities on which such high energy density conditions can be achieved and lists a number of key scientific questions about high energy density physics that can be addressed by this research. Several recommendations are presented that would facilitate the development of a comprehensive strategy for realizing these research opportunities.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1974-07 with total page 978 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Library of Congress Subject Headings written by Library of Congress and published by . This book was released on 2004 with total page 1396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt:
