Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-25T04:56:44.103Z Has data issue: false hasContentIssue false

Variational principles in high-frequency scattering*

Published online by Cambridge University Press:  24 October 2008

Ralph D. Kodis
Affiliation:
Cavendish Laboratory Cambridge*

Abstract

A pair of variational principles are formulated for two-dimensional scattering by obstacles. The first of these is in terms of the obstacle boundary values, and it is shown that a simple ‘optical’ trial function leads to an incorrect frequency dependence for the scattering cross-section. In the second, the obstacle is viewed as the analogue of an aperture coupling two half spaces. The geometric optics part of the cross-section can then be made explicit and is split off to leave a stationary form for the frequency correction. The zero-order calculation for the cross-section of a circle, using corresponding ‘optical’ trial functions, is found to have the correct (Ka)−2/3 frequency dependence.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1958

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)Debye, P.Phys. Z. 9 (1908), 775.Google Scholar
(2)Sommerfeld, A. and Runge, J.Ann. Phys., Lpz., (4) 35 (1911), 277.CrossRefGoogle Scholar
(3)MacDonald, H. M.Phil. Trans. A, 210 (1910), 113.Google Scholar
(4)MacDonald, H. M.Proc. Boy. Soc. A, 90 (1914), 50.Google Scholar
(5)Erdelyi, A. et al. Higher transcendental functions, p. 89, Vol. 2 (New York, 1953).Google Scholar
(6)Rubinow, S. I. and Wu, T. T.J. Appl. Phys. 27 (1956), 1032.CrossRefGoogle Scholar
(7)Keller, J. B., Lewis, R. M. and Seckler, B. D. New York University Research Report No. EM-81 (06 1955).Google Scholar
(8)MacDonald, H. M.Phil. Trans. A, 212 (1912), 299.Google Scholar
(9)Kay, I. and Keller, J. B.J. Appl. Phys. 25 (1954), 876.CrossRefGoogle Scholar
(10)Fock, V.J. Phys. (Moscow), 10 (1946), 130.Google Scholar
(11)Levine, H. and Schwinger, J.Commun. Pure Appl. Math. 3 (1950), 355.CrossRefGoogle Scholar
(12)Papas, C. H.J. Appl. Phys. 21 (1950), 318.CrossRefGoogle Scholar
(13)Kodis, R. D.J. Soc. Industr. Appl. Math. 2 (1954), 89.CrossRefGoogle Scholar
(14)Watson, G. N.Bessel functions, p. 229, 2nd ed. (Cambridge, 1945).Google Scholar
(15)Watson, G. N.Bessel functions, p. 417, 2nd ed. (Cambridge, 1945).Google Scholar
(16)Franz, W. and Deppermann, K.Ann. Phys., Lpz., (6) 10 (1952), 361.CrossRefGoogle Scholar
(17)Wu, T. T.Phys. Rev. 104 (1956), 1201.CrossRefGoogle Scholar
(18)Jones, D. S.Proc. Roy. Soc. A, 239 (1957), 338.Google Scholar
(19)Jones, D. S.Proc. Camb. Phil. Soc. 53 (1957), 691.CrossRefGoogle Scholar