Download or read book A Microscopic Theory of Fission Dynamics Based on the Generator Coordinate Method written by Walid Younes and published by Springer. This book was released on 2019-01-09 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces a quantum-mechanical description of the nuclear fission process from an initial compound state to scission. Issues like the relevant degrees of freedom throughout the process, the way of coupling collective and intrinsic degrees during the fission process, and how a nucleus divides into two separate daughters in a quantum-mechanical description where its wave function can be non-local, are currently being investigated through a variety of theoretical, computational, and experimental techniques. The term “microscopic” in this context refers to an approach that starts from protons, neutrons, and an effective (i.e., in-medium) interaction between them. The form of this interaction is inspired by more fundamental theories of nuclear matter, but still contains parameters that have to be adjusted to data. Thus, this microscopic approach is far from complete, but sufficient progress has been made to warrant taking stock of what has been accomplished so far. The aim is to provide, in a pedagogical and comprehensive manner, one specific approach to the fission problem, originally developed at the CEA Bruyères-le-Châtel Laboratory in France. Intended as a reference for advanced graduate students and researchers in fission theory as well as for practitioners in the field, it includes illustrative examples throughout the text to make it easier for the reader to understand, implement, and verify the formalism presented.
Download or read book Fission Dynamics in a Microscopic Theory written by Shi Jin and published by . This book was released on 2019 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is concerned with the application of the time-dependent density functional theory (TDDFT) to investigate the fission dynamics of atomic nucleus, which is still one of the most complicated problem in nuclear physics and a full microscopic interpretation is still missing. The establishment of the time-dependent superfluid local density approximation (TDSLDA) and the increasing power of computing resources make the three-dimensional symmetry unrestricted simulations of fission dynamics possible in recent years. In this work, a qualitative new nuclear energy density functional (NEDF) is developed, which contains only seven uncorrelated fitting parameters, and have excellent performance in describing various nuclear properties, e.g. nuclear mass, charge radii, neutron separation energy, shell structure, and deformation properties like the height of fission barriers and the excitation energy of fission isomer. Using such NEDF and another popular NEDF among fission practitioners, SkM*, a comprehensive study of fission dynamics with TDSLDA formalism is presented. The role of pairing correlations in fission dynamics is demonstrated quantitatively. It is also shown that independent TDSLDA trajectories with different initial conditions on the potential energy surface generate almost the same fission fragment (FF) configurations, e.g. the mass split, total kinetic energy, total excitation energies etc. An important aspect of this study is to provide a quantitative validation that the fission dynamics from saddle to scission is a non-adiabatic, overdamped one. To overcome the limitation of TDDFT that fails to produce the variances in the FF properties, a novel method in the spirit of the classical Langevin approach is promoted to include fluctuations and dissipations into the TDDFT framework. Promising results are obtained in a simpler nuclear hydrodynamics simulation, while its implementation in full TDSLDA calculation is still challenging.
Download or read book Microscopic Theory of Fission written by and published by . This book was released on 2008 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theory of Nuclear Fission written by Hans J. Krappe and published by Springer Science & Business Media. This book was released on 2012-02-06 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together various aspects of the nuclear fission phenomenon discovered by Hahn, Strassmann and Meitner almost 70 years ago. Beginning with an historical introduction the authors present various models to describe the fission process of hot nuclei as well as the spontaneous fission of cold nuclei and their isomers. The role of transport coefficients, like inertia and friction in fission dynamics is discussed. The effect of the nuclear shell structure on the fission probability and the mass and kinetic energy distributions of the fission fragments is presented. The fusion-fission process leading to the synthesis of new isotopes including super-heavy elements is described. The book will thus be useful for theoretical and experimental physicists, as well as for graduate and PhD students.
Download or read book A Microscopic Theory of Low Energy Fission written by and published by . This book was released on 2013 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Microscopic Theory of Fission written by and published by . This book was released on 2017 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microscopic Description of Nuclear Fission at Finite Temperature written by Jordan David McDonnell and published by . This book was released on 2012 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: While a predictive, microscopic theory of nuclear fission has been elusive, advances in computational techniques and in our understanding of nuclear structure are allowing us to make significant progress. Through nuclear energy density functional theory, we study the fission of thorium and uranium isotopes in detail. These nuclides have been thought to possess hyperdeformed isomers in the third minima of their potential energy surfaces, but microscopic theories tend to estimate either shallow or non-existent third minima in these nuclei. We seek an explanation in terms of neutron shell effects. We study how the fission pathways, the symmetry, and the third minima of these nuclei evolve with increasing excitation energy. We then study the fission of mercury-180, in which a recent experiment unexpectedly discovered that this nucleus fissions asymmetrically. We find that the fission of mercury-180 and mercury-198 is driven by subtleties in shell effects on the approach to scission. We finally survey fission barrier heights and spontaneous fission half-lives of several actinide nuclei, from radium to californium. For a new energy density functional, we find good agreement between our calculations and available experimental data, lending confidence to the predictions of our theory beyond experimentally measured nuclei.
Download or read book The Microscopic Theory of Fission written by and published by . This book was released on 2009 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fission-fragment properties have been calculated for thermal neutron-induced fission on a 239Pu target, using constrained Hartree-Fock-Bogoliubov calculations with a finite-range effective interaction. A quantitative criterion based on the interaction energy between the nascent fragments is introduced to define the scission configurations. The validity of this criterion is benchmarked against experimental measurements of the kinetic energies and of multiplicities of neutrons emitted by the fragments.
Download or read book Fragment Yields Calculated in a Time Dependent Microscopic Theory of Fission written by and published by . This book was released on 2012 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Introduction to Nuclear Fission written by Walid Younes and published by Springer Nature. This book was released on 2021-11-15 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: This hands-on textbook introduces physics and nuclear engineering students to the experimental and theoretical aspects of fission physics for research and applications through worked examples and problem sets. The study of nuclear fission is currently undergoing a renaissance. Recent advances in the field create the opportunity to develop more reliable models of fission predictability and to supply measurements and data to critical applications including nuclear energy, national security and counter-proliferation, and medical isotope production. An Introduction to Nuclear Fission provides foundational knowledge for the next generation of researchers to contribute to nuclear fission physics.
Download or read book Microscopic Description of Fission Dynamics written by and published by . This book was released on 2015 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Master Equations in the Microscopic Theory of Nuclear Collective Dynamics written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Workshop on Fusion Dynamics at the Extremes written by Yu. Ts Oganessian and published by World Scientific. This book was released on 2001 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the properties and fusion dynamics of very heavy nuclei. It contains the latest experimental results on the formation and fission of superheavy nuclei and on the near-barrier fusion of light exotic nuclei, along with the different theoretical approaches to the description of fusion dynamics and microscopic properties of superheavy nuclei. The book also discusses nuclear collective dynamics and expectations from the use of accelerated beams of radioactive nuclei in fusion reactions. Contents: Aspects of Fusion, Fission and Cluster Radioactivity (W Greiner); Superheavy Nuclei in Deformed Mean-Field Calculations (T Brvenich et al.); The Synthesis of Superheavy Nuclei in the 48 Ca+ 244 Pu Reaction (Yu Ts Oganessian et al.); Fusion-Fission of Superheavy Nuclei at Low Excitation Energies (M G Itkis et al.); Semi-Bubbles and Bubbles: a New Kind of Superheavy Nuclei (K Dietrich); Reaction Theory for Synthesis of the Superheavy Elements (Y Abe); Fusion-Fission Dynamics of the Synthesis of Superheavy Nuclei (V I Zagrebaev); Sub-Barrier Fusion and Multi Nucleon Transfer in Medium-Heavy Nuclei (F Scarlassara et al.); Mechanisms of Sub-Barrier Fusion Enhancement (N Rowley); Transfer, Breakup, and Fusion Reactions of 6 He with 209 Bi Near the Coulomb Barrier (J J Kolata); Study of Sub-Barrier and Near-Barrier Fusion of Halo Nuclei (N Alamanos et al.); and other papers. Readership: Graduate students, researchers and lecturers in nuclear physics.
Download or read book Effect of Fission Dynamics on the Spectra and Multiplicities of Prompt Fission Neutrons written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: With the goal of examining their effect on the spectra and multiplicities of the prompt neutrons emitted in fission, we discuss recent advances in a unified macroscopic-microscopic description of large-amplitude collective nuclear dynamics. The conversion of collective energy into single-particle excitation energy is calculated for a new surface-plus-window dissipation mechanism. By solving the Hamilton equations of motion for initial conditions appropriate to fission, we obtain the average fission-fragment translational kinetic energy and excitation energy. The spectra and multiplicities of the emitted neutrons, which depend critically upon the average excitation energy, are then calculated on the basis of standard nuclear evaporation theory, taking into account the average motion of the fission fragments, the distribution of fission-fragment residual nuclear temperature, the energy dependence of the cross section for the inverse process of compound-nucleus formation, and the possibility of multiple-chance fission. Some illustrative comparisons of our calculations with experimental data are shown.
Download or read book Charge and Energy Transfer Dynamics in Molecular Systems written by Volkhard May and published by John Wiley & Sons. This book was released on 2011-04-27 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 3rd edition has been expanded and updated to account for recent developments, while new illustrative examples as well as an enlarged reference list have also been added. It naturally retains the successful concept of its predecessors in presenting a unified perspective on molecular charge and energy transfer processes, thus bridging the regimes of coherent and dissipative dynamics, and establishing a connection between classic rate theories and modern treatments of ultrafast phenomena. Among the new topics are: - Time-dependent density functional theory - Heterogeneous electron transfer, e.g. between molecules and metal or semiconductor surfaces - Current flows through a single molecule. While serving as an introduction for graduate students and researchers, this is equally must-have reading for theoreticians and experimentalists, as well as an aid to interpreting experimental data and accessing the original literature.
Download or read book Nuclear Fission written by Patrick Talou and published by Springer. This book was released on 2024-01-16 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides advanced students and postdocs, as well as current practitioners of any field of nuclear physics involving fission an understanding of the nuclear fission process. Key topics covered are: fission cross sections, fission fragment yields, neutron and gamma emission from fission and key nuclear technologies and applications where fission plays an important role. It addresses both fundamental aspects of the fission process and fission-based technologies including combining quantitative and microscopic modeling.
Download or read book THEORY 1 written by and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
