Nuclear constitution and the interpretation of fission phenomena
About: This article is published in Physical Review.The article was published on 1953-03-01. It has received 1462 citations till now. The article focuses on the topics: Fission products & Fission.
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TL;DR: In this paper, the authors review the present status of self-consistent mean field (SCMF) models for describing nuclear structure and low-energy dynamics and present several extensions beyond the mean-field model which are currently used.
Abstract: The authors review the present status of self-consistent mean-field (SCMF) models for describing nuclear structure and low-energy dynamics. These models are presented as effective energy-density functionals. The three most widely used variants of SCMF's based on a Skyrme energy functional, a Gogny force, and a relativistic mean-field Lagrangian are considered side by side. The crucial role of the treatment of pairing correlations is pointed out in each case. The authors discuss other related nuclear structure models and present several extensions beyond the mean-field model which are currently used. Phenomenological adjustment of the model parameters is discussed in detail. The performance quality of the SCMF model is demonstrated for a broad range of typical applications.
1,822 citations
TL;DR: The fourth version of the Japanese Evaluated Nuclear Data Library has been produced in cooperation with the Japanese Nuclear Data Committee as mentioned in this paper, and much emphasis is placed on the improvement of the original library.
Abstract: The fourth version of the Japanese Evaluated Nuclear Data Library has been produced in cooperation with the Japanese Nuclear Data Committee. In the new library, much emphasis is placed on the impro...
1,699 citations
TL;DR: In this article, a semi-empirical theory of nuclear masses and deformations is presented, where the potential energy of a nucleus, considered as a function of N, Z and the nuclear shape, is given by the liquid-drop model, modified by a shell correction.
1,376 citations
TL;DR: In this article, the authors survey the hierarchy of theoretical approximations leading to the jellium model, including various extensions, including local density approximation to exchange and correlation effects, which greatly simplifies self-consistent calculations of the electronic structure.
Abstract: The jellium model of simple metal clusters has enjoyed remarkable empirical success, leading to many theoretical questions. In this review, we first survey the hierarchy of theoretical approximations leading to the model. We then describe the jellium model in detail, including various extensions. One important and useful approximation is the local-density approximation to exchange and correlation effects, which greatly simplifies self-consistent calculations of the electronic structure. Another valuable tool is the semiclassical approximation to the single-particle density matrix, which gives a theoretical framework to connect the properties of large clusters with the bulk and macroscopic surface properties. The physical properties discussed in this review are the ground-state binding energies, the ionization potentials, and the dipole polarizabilities. We also treat the collective electronic excitations from the point of view of the cluster response, including some useful sum rules.
1,357 citations
TL;DR: In this article, a general algorithm for constructing coherent states of dynamical groups for a given quantum physical system is presented, and the result is that the coherent states are isomorphic to a coset space of group geometrical space.
Abstract: In this review, a general algorithm for constructing coherent states of dynamical groups for a given quantum physical system is presented. The result is that, for a given dynamical group, the coherent states are isomorphic to a coset space of group geometrical space. Thus the topological and algebraic structure of the coherent states as well as the associated dynamical system can be extensively discussed. In addition, a quantum-mechanical phase-space representation is constructed via the coherent-state theory. Several useful methods for employing the coherent states to study the physical phenomena of quantum-dynamic systems, such as the path integral, variational principle, classical limit, and thermodynamic limit of quantum mechanics, are described.
1,354 citations
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TL;DR: In this paper, the crossing of a polar and homopolar state of a molecule with stationary nuclei has been studied, and the essential features may be illustrated in the crossing.
Abstract: The crossing of energy levels has been a matter of considerable discussion. The essential features may be illustrated in the crossing of a polar and homopolar state of a molecule. Let ψ1 ( x /R), ψ2 ( x /R) be two electronic eigenfunctions of a molecule with stationary nuclei. Let these eigenfunctions have the property that for R≫R, ψ1 has polar characteristics, ψ2 homopolar; while at R≪R, ψ2 has polar characteristics, ψ1 homopolar. In the region R=R these two eigenfunctions may be said to exchange their characteristics.
3,509 citations
1,584 citations
TL;DR: On the basis of the liquid drop model of atomic nuclei, an account of the mechanism of nuclear fission is given in this article, where conclusions are drawn regarding the variation from nucleus to nucleus of the critical energy required for fission, and regarding the dependence of fission cross section for a given nucleus on energy of the exciting agency.
Abstract: On the basis of the liquid drop model of atomic nuclei, an account is given of the mechanism of nuclear fission. In particular, conclusions are drawn regarding the variation from nucleus to nucleus of the critical energy required for fission, and regarding the dependence of fission cross section for a given nucleus on energy of the exciting agency. A detailed discussion of the observations is presented on the basis of the theoretical considerations. Theory and experiment fit together in a reasonable way to give a satisfactory picture of nuclear fission.
1,281 citations
774 citations
TL;DR: In this article, the authors apply statistical methods to the calculation of nuclear processes provided that the energies involved are large in comparison with the lowest excitation energies of nuclei Expressions are obtained for the emission probability of neutrons or charged particles by highly excited heavy nuclei.
Abstract: It is possible to apply statistical methods to the calculation of nuclear processes provided that the energies involved are large in comparison with the lowest excitation energies of nuclei Expressions are obtained for the emission probability of neutrons or charged particles by highly excited heavy nuclei These expressions are built up in a similar way to the formula for the probability of evaporation of a particle from a body at low temperatures In applying it to the impact of high energy neutrons on heavy nuclei, the mean energy loss per impact turns out to be $E[1\ensuremath{-}2{(\frac{a}{E})}^{\frac{1}{2}}]$ where $E$ is the energy of the incident neutrons and $a$ is dependent on the nuclear structure; we can put approximately $a\ensuremath{\sim}005\ensuremath{-}02$ MV The energy distribution of the scattered neutrons is approximately a Maxwellian one with a mean energy of $2{(\mathrm{aE})}^{\frac{1}{2}}$
709 citations