Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-23T14:32:27.387Z Has data issue: false hasContentIssue false

A note on the calculation of the spacing of energy levels in a heavy nucleus

Published online by Cambridge University Press:  24 October 2008

I. N. Sneddon
Affiliation:
The Department of Natural Philosophy, The University of Glasgow
B. F. Touschek
Affiliation:
The Department of Natural Philosophy, The University of Glasgow

Extract

It is known as a result of various experiments on slow neutrons (1) that a heavy nucleus possesses an enormous number of energy levels which are very closely spaced if the nucleus is highly excited. Strong theoretical reasons for the existence of this great number of levels were given by Bohr (2) and since then various attempts have been made to calculate the number of energy levels of a heavy nucleus. In the first of these, due to Bethe(3), it was assumed that the interaction between the nucleons was small so that the nucleus could be treated as a gas. The alternative assumption, that we may consider the interaction to be large in comparison with the kinetic energy of the nucleons, was proposed by Bohr and Kalckar(4). In the present note we assume as our model a nucleus consisting of neutrons and protons independent of one another; we then have a neutron-gas in equilibrium with a proton-gas, Fermi-Dirac statistics being applied to both.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1948

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

(1)Frisch, R. and Placzek, G.Nature, London, 137 (1936), 357.CrossRefGoogle Scholar
Weekes, D. F., Livingston, M. S. and Bethe, H. A.Phys. Rev. 49 (1936), 471.CrossRefGoogle Scholar
Rasetti, F., Fink, G., Goldsmith, H. H. and Mitchell, G. A.Phys. Rev. 49 (1936), 869.Google Scholar
Collie, C. H.Nature, London, 137 (1936), 614.CrossRefGoogle Scholar
Amaldi, E. and Fermi, E.Ricerca Sci. 1 (1936), Nos. 78.Google Scholar
(2)Bohr, N.Nature, London, 137 (1936), 344, 351.CrossRefGoogle Scholar
Breit, G. and Wigner, E.Phys. Rev. 49 (1936), 519.CrossRefGoogle Scholar
(3)Bethe, H. A.Phys. Rev. 50 (1936), 332.CrossRefGoogle Scholar
Oppenheimer, J. R. and Serber, E.Phys. Rev. 50 (1936), 391.Google Scholar
(4)Bohr, N. and Kalckar, F.Kgl. Dansk. Akad. (1939).Google Scholar
(5)Debye, P.Math. Ann. 67 (1909), 535. Münch. Ber. 40 (1910), No. 5.CrossRefGoogle Scholar
Fowler, R. H.Statiatical mechanics, 2nd ed. (Cambridge, 1936), p. 36.Google Scholar
(6)Wilson, H. A.Phys. Rev. 69 (1946), 538.CrossRefGoogle Scholar
(7)Schrödinger, E.Statistical thermodynamics (Cambridge, 1946).Google Scholar
(8)Fermi, E.Thermodynamics (London and Glasgow, 1938), p. 81.Google Scholar
(9)Titchmarsh, E. C.An introduction to the theory of Fourier integrals (Oxford, 1937), p. 6.Google Scholar
(10)Dirac, P. A. M.The principles of quantum mechanics (Oxford, 1935), p. 71.Google Scholar
(11)Watson, G. N.A treatise on Bessel functions, 2nd ed. (Cambridge, 1944).Google Scholar
(12)Bethe, H. A.Rev. Mod. Phys. 9 (1937), § 60.CrossRefGoogle Scholar
(13)Jahnke, E. and Emde, F.Funktionentafeln (Leipzig, 1933), p. 323.Google Scholar
(14)Wiedenbeck, M. L.Phys. Rev. 68 (1945), 1.CrossRefGoogle Scholar
(15)Bethe, H. A.Rev. Mod. Phys. 9 (1937), 85.CrossRefGoogle Scholar
(16)Bardeen, J.Phys. Rev. 51 (1945), 799.CrossRefGoogle Scholar