Download or read book A Semi Empirical Study of the Shell Model Proton Neutron Interaction written by J. M. Ferguson and published by . This book was released on 1964 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effective proton-neutron interaction in nuclei is approximated by an extreme short-range force with an ordinary and a spin-dependent component. This interaction is applied to several odd-odd nuclei with two nucleons (or holes) outside of closed shells throughout the periodic table. Simple Harmonic Oscillator wave functions are used to evaluate dependent to ordinary force are determined empirically. It is found that the simple model reproduces the interaction with about 30 percent accuracy. It also indicates a stronger interaction energy should be used when the proton and neutron are in the same single-particle state than when they are in different states. (Author).
Download or read book The Nuclear Shell Model written by Kris Heyde and published by Springer. This book was released on 2013-12-20 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the present edition, a number of new features have been added. First of all, a number of typographical errors that had crept into the text have been corrected. More importantly, a number of new examples, figures and smaller sections have been added. In evaluating the two-body matrix elements which characterize the residual interaction, attention has been paid to the multipole expansion and insight into the importance of various multipoles is presented. The 18 example of 0 is now worked out for all the different angular momentum states in the section on configuration mixing. Some additional comments on how to determine one- and two-body matrix elements in jn configurations, on isospin and the application of isospin to the study of light odd-odd nuclei are included. In Chap. 3, a small section on the present use of large-scale shell model calculations and a section on experimental tests of how a nucleon actually moves inside the nucleus (using electromagnetic probing of nucleonic motion) has been added. In Chap. 4, some recent applications of the study of quadrupole motion in jn particle systems (with reference to the Po, Rn, Ra nuclei) are presented. In the discussion of magnetic dipole moments, the effects and importance of collective admixtures are pointed out and discussed. In Chap. 5, some small additions relating to the particle-hole conjugation and to the basic Hartree-Fock theory have been made. In Chap.
Download or read book The Nuclear Shell Model written by Kris L.G. Heyde and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is aimed at enabling the reader to obtain a working knowledge of the nuclear shell model and to understand nuclear structure within the framework of the shell model. Attention is concentrated on a coherent, self-contained exposition of the main ideas behind the model with ample illustrations to give an idea beyond formal exposition of the concepts. Since this text grew out of a course taught for advanced undergraduate and first-year graduate students in theoretical nuclear physics, the accents are on a detailed exposition of the material with step-by-step derivations rather than on a superficial description of a large number of topics. In this sense, the book differs from a number of books on theoretical nuclear physics by narrowing the subject to only the nuclear shell model. Most of the expressions used in many of the existing books treating the nuclear shell model are derived here in more detail, in a practitioner's way. Due to frequent student requests I have expanded of detail in order to take away the typical phrase " . . . after some the level simple and straightforward algebra one finds . . . ". The material could probably be treated in a one-year course (implying going through the problem sets and setting up a number of numerical studies by using the provided computer codes). The book is essentially self-contained but requires an introductory course on quantum mechanics and nuclear physics on a more general level.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1971 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book U S Government Research Reports written by and published by . This book was released on 1964 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1974 with total page 1148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Theory Index written by and published by . This book was released on 1964 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gamow Shell Model written by Nicolas Michel and published by Springer Nature. This book was released on 2021-04-24 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides the first graduate-level, self-contained introduction to recent developments that lead to the formulation of the configuration-interaction approach for open quantum systems, the Gamow shell model, which provides a unitary description of quantum many-body system in different regimes of binding, and enables the unification in the description of nuclear structure and reactions. The Gamow shell model extends and generalizes the phenomenologically successful nuclear shell model to the domain of weakly-bound near-threshold states and resonances, offering a systematic tool to understand and categorize data on nuclear spectra, moments, collective excitations, particle and electromagnetic decays, clustering, elastic and inelastic scattering cross sections, and radiative capture cross sections of interest to astrophysics. The approach is of interest beyond nuclear physics and based on general properties of quasi-stationary solutions of the Schrödinger equation – so-called Gamow states. For the benefit of graduate students and newcomers to the field, the quantum-mechanical fundamentals are introduced in some detail. The text also provides a historical overview of how the field has evolved from the early days of the nuclear shell model to recent experimental developments, in both nuclear physics and related fields, supporting the unified description. The text contains many worked examples and several numerical codes are introduced to allow the reader to test different aspects of the continuum shell model discussed in the book.
Download or read book Efficient Modeling of Nuclei Through Coupling of Proton and Neutron Wavefunctions written by and published by . This book was released on 2018 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes a nuclear shell model code which aims for a significant reduction in computer resource usage while retaining accuracy of results as compared to numerically exact solutions. I begin with an introduction to the configuration interaction and shell model calculations. I then motivate the need for a proton-neutron decomposition of the Hamiltonian, and present evidence for the viability of such a decomposition to reduce the size of the model space, through three different studies. The first is a series of calculations of proton-neutron entanglement entropy, a relatively novel approach in shell model calculations. Entanglement entropy measures the distribution of wavefunction coefficients, and thus the viability of truncation of a model space. These calculations study the strength and origin of the isospin dependence of the proton-neutron entanglement entropy. The second is a toy model that attempts to reproduce the entanglement entropy properties of realistic nuclear calculations. The third is a strength function decomposition of exact wavefunctions in an explicit proton-neutron formalism. Finally, I discuss a code to calculate nuclear wave-functions by a coupling of proton and neutron wave-functions which are calculated beforehand by an existing interacting shell model code. Results and convergence properties of this code are provided and discussed.
Download or read book Theory of the Nuclear Shell Model written by R. D. Lawson and published by Oxford University Press, USA. This book was released on 1980 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shell model Semi empirical Nuclear Masses II written by Nissan Zeldes and published by . This book was released on 1967 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simple Models of Complex Nuclei written by Igal Talmi and published by Taylor & Francis. This book was released on 1993 with total page 1110 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work deals with the shell model and interacting boson model and their applications to the structure of atomic nuclei. The author systematically develops these models from an elementary level, through an introduction to tensor algebra, to the use of group theory in spectroscopy. Igal Talmi, Weizman Institute of Science, Rehovot, Israel
Download or read book The Practitioner s Shell Model written by George F. Bertsch and published by Elsevier Publishing Company. This book was released on 1972 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Science Abstracts written by and published by . This book was released on 1965 with total page 2344 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Semiempirical Shell Model Calculation in the N written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of the present work was to determine a consistent set of single-particle energies and two-body interaction matrix elements that are relevant in the region around 146Gd nucleus. The resulting values were used to calculate the medium- and high-spin states that are fed by the decay of the 550 ns isomer in 147Gd. 5 refs., 1 fig., 6 tabs.
Download or read book Isospin breaking Interactions in the Nuclear Shell Model written by Aaron Magilligan and published by . This book was released on 2021 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ever advancing scale of experimental nuclear physics has lit a fire under nuclear theorists. With the inevitable explosion in the number of exotic isotopes available for study at the soon to be operational Facility for Rare Isotope Beams and other rare isotope labs, the need for quantitative descriptions of nuclei far from stability is clear.The Nuclear Shell Model allows for the calculation of realistic nuclear wavefunctions using configuration-interaction theory. This theory examines only the valence nucleons in a restricted model space or "nuclear shell" and treats the filled shells in the core of the nucleus as inert. Interactions used in this theory usually take the form of one- and two-body terms which can be built up from fundamental theory using various many body methods and are continually being improved. The ab initio based methods now include three-body interactions together with improved methods for handling short-ranged correlations and model space truncations. This enables them to describe binding energies within several MeV and energy spectra within about 500 keV.One can phenomenologically improve upon these interactions by using the energy data for nuclei in a given mass region to obtain effective two-body matrix elements for a given model space. An effective method for doing this is to start with an ab initio based Hamiltonian and then to modify the best determined linear combinations of interaction parameters as determined by the energy data using what is called the singular value decomposition method. This can be thought of as a truncation of the allowed parameter space. The result is that both binding and excitation energies can be described to within 150-200 keV. The relatively small modifications to the ab initio interaction parameters reflect deficiencies in the many-body methods and their inputs.This method has resulted in widely used Hamiltonians for several model spaces. Universal effective sd-shell Hamiltonians have a history dating back to the 1970s, and the newest updates are presented in this dissertation. The USDC interaction, as it is called, and its companion interactions are the first effective sd-shell interactions that incorporate energies in the fitting protocol from proton rich nuclei and explicitly includes isospin-breaking terms. Apart from the addition of a Coulomb interaction, an isotensor term is added to the strong interaction in order to reproduce the oscillation found in the c-coefficients of the Isobaric Multiplet Mass Equation. A modified version of Coulomb is used in the USDCm interaction, which was constrained to better reproduce mirror energy differences.Experimental binding and excitation energies across the shell are reproduced by USDC, apart from the known island of inversion nuclei and the neutron-rich fluorine isotopes. A single-particle model of the Thomas-Ehrman shift is developed to account for coupling to the continuum not present in the shell model results for nuclei at or near the proton dripline. Using this model and the improved theoretical binding energies, new predictions for the proton and neutron driplines are presented. The possibility of 34Ca being a two-neutron emitter is explored.Isospin level mixing of isobaric analogue states with nearby states can significantly impact nuclear decays. Several cases with experimentally measured isospin mixing are explained with the new interactions. However, USDCm over predicts the strength of the associated matrix elements. This motivates a refinement of USDC in which an isovector term is added to the strong interaction and constrained to reproduce changes of mirror energy differences in the isobaric doublets. This is shown to provide the benefits of the modified Coulomb interaction without its detriments.An effective fp-shell interaction is presented tailored to the neutron rich calcium isotopes out to 60Ca. This is constrained with the nuclear interaction fitting code FINCH, developed during the creation of the USDC interactions. This interaction is shown to be a good renormalized fp-shell interaction and several predictions for unobserved states are presented. Using this and inter-model comparisons leads us to conclude that 60Ca is likely doubly-magic to a similar level as $. {68}$Ni.Following these successful implementations of effective universal configuration-interaction Hamiltonians, future research aims to develop an sdpf model space interaction for deeper study of the N=20, 28, and 42 islands of inversion.
