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Nuclear-shell theories

Before concluding this section, it must be pointed out that there are other fields of application of the SRH formalism. Thus, Karwowski et al. have used it in the study of the statistical theory of spectra [30,38]. Also, the techniques used in developing the p-SRH algorithms have proven to be very useful in other areas such as the nuclear shell theory [39,40]. [Pg.66]

Dalton, B. J. (1971), Nonrigid Molecule Effects on the Rovibronic Energy Levels and Spectra of Phosphorous Pentafluoride, J. Chem. Phys. 54,4745. de Shalit, A., and Talmi, 1. (1963), Nuclear Shell Theory, Academic Press, N.Y. [Pg.225]

Four decades ago, Bell [3] introduced a particle-hole conjugation operator CB into nuclear shell theory. Its operator algebra is essentially isomorphic to that of Cq (for example, CB is unitary), the filled Dirac sea now corresponding to systems with half-filled shells. This was later extended to other areas of physics. For example,... [Pg.24]

STa63] de Shalit A and Talmi 1 1963 Nuclear shell theory (Academic Press, New York and London). [Pg.424]

De Shalit, A., Talmi, I. Nuclear shell theory. New York Academic Press 1963. [Pg.81]

A. De-Shalit, I. Takni, Nuclear Shell Theory, Academic Press, New York, 1963. [Pg.214]

In both the electronic and nuclear-shell theories, one is dealing with a many-body problem for which there is no analytical solution. As a result, the explanations provided in both cases are approximate and rely to some extent on empirical evidence, such as the precise ordering of levels. These relative orderings of levels have not been deduced from first principles, contrary to the impression created by some presentations. Indeed, problems are more severe in the nuclear case, in view of the greater complexity of the nucleus. Just as the + /rule is obtained empirically in the electronic case, as described in chapter 9, so the nuclear ordering by the aujbau principle is also obtained by appeal to empirical data. ... [Pg.265]

The explanation of the magic numbers by nuclear-shell theory is nevertheless a remarkable achievement in that the number of nucleons per level as well as the relationship between the various quantum numbers is deduced from first principles even if the ordering of levels is not. [Pg.265]

Mayer, M. Goeppert, and J. H. D. Jensen, Elementary Theory of Nuclear Shell Structure (New York and London John Wiley and Sons, Inc., 1955). [Pg.811]

During recent decades a great amount of knowledge about the properties of atomic nuclei has been gathered. An extensive theory of nucleonic interactions and nuclear structure [liquid-drop theory (7), shell theory (2, 3), unified theory (4), cluster theory (5—7)] has been developed... [Pg.816]

The shell theory has had great success in accounting for many nuclear properties (3). The principal quantum number n for nucleons is usually taken to be n, + 1, where nr, the radial quantum number, is the number of nodes in the radial wave function. (For electrons n is taken to be nr + / +1 / is the azimuthal quantum number.) Strong spin-orbit coupling is assumed,... [Pg.816]

Figure 6.3 Energy level pattern and spectroscopic labeling of states from the schematic shell model. The angular momentum coupling is indicated at the left side and the numbers of nucleons needed to fill each orbital and each shell are shown on the right side. From M. G. Mayer and J. H. D. Jenson, Elementery Theory of Nuclear Shell Structure, Wiley, New York, 1955. Figure 6.3 Energy level pattern and spectroscopic labeling of states from the schematic shell model. The angular momentum coupling is indicated at the left side and the numbers of nucleons needed to fill each orbital and each shell are shown on the right side. From M. G. Mayer and J. H. D. Jenson, Elementery Theory of Nuclear Shell Structure, Wiley, New York, 1955.
R. D. Lawson, "Theory of Nuclear Shell Model", Clarendon Press,... [Pg.55]

Element abundance data were useful not only in astrophysics and cosmology but also in the attempts to understand the structure of the atomic nucleus. [74] As mentioned, this line of reasoning was adopted by Harkins as early as 1917, of course based on a highly inadequate picture of the nucleus. It was only after 1932, with the discovery of the neutron as a nuclear component, that it was realized that not only is the atomic mass number related to isotopic abundance, but so are the proton and neutron numbers individually. Cosmochemical data played an important part in the development of the shell model, first proposed by Walter Elsasser and Kurt Guggenheimer in 1933-34 but only turned into a precise quantitative theory in the late 1940s. [75] Guggenheimer, a physical chemist, used isotopic abundance data as evidence of closed nuclear shells with nucleon numbers 50 and 82. [Pg.175]

Effective Hamiltonians and effective operators are used to provide a theoretical justification and, when necessary, corrections to the semi-empirical Hamiltonians and operators of many fields. In such applications, Hq may, but does not necessarily, correspond to a well defined model. For example. Freed and co-workers utilize ab initio DPT and QDPT calculations to study some semi-empirical theories of chemical bonding [27-29] and the Slater-Condon parameters of atomic physics [30]. Lindgren and his school employ a special case of DPT to analyze atomic hyperfine interaction model operators [31]. Ellis and Osnes [32] review the extensive body of work on the derivation of the nuclear shell model. Applications to other problems of nuclear physics, to solid state, and to statistical physics are given in reviews by Brandow [33, 34], while... [Pg.468]

M. Mayer, Elementary Theory of Nuclear Shell Structure, Wiley, New York... [Pg.266]

The mechanisms and data of the fission process have been reviewed recently by Leachman (70). Several different approaches have been used in an effort to explain the asymmetry of the fission process as well as other fission parameters. These approaches include developments of the liquid drop model (50, 51,102), calculations based on dependence of fission barrier penetration on asymmetry (34), the effect of nuclear shells (52, 79, 81), the determinations of the fission mode by level population of the fragments (18, 33, 84), and finally the consideration of quantum states of the fission nucleus at the saddle point (15, 108). All these approaches require a mass formula whereby the masses of the fission fragments far removed from stability may be determined. The lack of an adequate mass formula has hindered the development of a satisfactory theory of fission. The fission process is highly complex and it is not surprising that the present theories fall short of a full explanation. [Pg.332]

R.D. Lawson, Theory of the Nuclear Shell Model (Clarendon Press, Oxford, 1980) p. 208. [Pg.70]

Realistic nuclear structure theory has traditionally been formulated in a framework which is tailored to the features of the simple mean-field shell model including its strong single-particle (sp) spin-orbit potential [1,2]. The introduction of a small model space which supposedly includes the essential configurations to describe the low-energy excitations, plays a central role in this traditional approach. An important early example of this method is provided by the seminal work of... [Pg.119]

Feenberg, E. The shell structure of the nucleus. Princeton The University Press 1954. — Mayer, M. G., and J. H. Jensen Elementary theory of nuclear shell structure. New York John Wiley 1955. [Pg.199]


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See also in sourсe #XX -- [ Pg.124 ]

See also in sourсe #XX -- [ Pg.124 ]




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