Hostname: page-component-848d4c4894-ttngx Total loading time: 0 Render date: 2024-05-04T14:14:50.000Z Has data issue: false hasContentIssue false

Similarity solutions of the steady state cosmic-ray equation of transport

Published online by Cambridge University Press:  17 February 2009

G. M. Webb
Affiliation:
Department of Mathematics, Monash University, Clayton, Vic. 3168, Australia
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Similarity solutions of the steady-state equation of transport for the distribution function F0 of cosmic rays in the interplanetary region are obtained by theuse of transformation groups. The solutions are derived in detail for a spherically-symmetric model of the interplanetary region with an effective radial diffusion coefficient κ = κ0(p)rb with r the heliocentric radial distance. p the particle momentum, κ0(p) an arbitary function of p, and the solar wind velocity is radial and of constant speed V. Solutions for which the similarity variable η is a function of r only are also derived; these are of particular impoartance when the F0 is specified on a boundary of given radius. Non spherically-symmetric solutions can also be obtained by group methods and examples of such solutions are listed, without derivation, for the equation of transport incorporating the effects of anisotropic diffusion (diffusion coefficient κ1 in the radial direction and κ2 normal to it). The solutions are the most extensive steady-state analytic solutions yet obtained, and contain previous analytic solutions as special cases.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1976

References

[1]Abramowitz, M. and Stegun, I. A., Handbook of Mathematical Functions, Dover, New York (1965).Google Scholar
[2]Bluman, G. W., Construction of Solutions to Partial Differential Equations by the use of Lie Groups, Ph.D. Thesis, California Institute of Technology, (1967).Google Scholar
[3]Bluman, G. W.. ‘Similarity solutions of the one-dimensional Fokker-Planck equation’. Int. J. Non-Lin. Mech. 6, (1971), 143.CrossRefGoogle Scholar
[4]Bluman, G. W., ‘Applications of the general similarity solution of the heat equation to boundary value problems’, Quart. J. Appl. Math., 31, (1974), 403.CrossRefGoogle Scholar
[5]Bluman, G. W. and Cole, J. D., ‘The general similarity solution of the heat equation’, J. Math. and Mechanics, 18 (1969), 1025.Google Scholar
[6]Bluman, G. W. and Cole, J. D., Similarity Methods for Differential Equations, (A.M.S. publications 13), Springer-Verlag, New York (1974).CrossRefGoogle Scholar
[7]Dolginov, A. Z. and Toptygin, I. N., ‘Diffusion of cosmic particles in the interplanetary medium’, Geomag. and Aeron., 7 (1967), 785.Google Scholar
[8]Dolginov, A. Z. and Toptygin, I. N., ‘Cosmic-rays in the interplanetary magnetic fields’, Icarus, 8 (1968), 54.CrossRefGoogle Scholar
[9]Fisk, L. A., Behaviour of Cosmic-Rays in the Interplanetary Medium, Ph.D. Thesis, University of California, San Diego, (1969).Google Scholar
[10]Fisk, L. A. and Axford, W. I., ‘Solar modulation of galactic cosmic-rays, I’, J. Geophys. Res., 74 (1969), 4973.CrossRefGoogle Scholar
[11]Gleeson, L. J. and Axford, W. I., ‘Cosmic-rays in the interplanetary medium’, Astrophys. J. Lett., 149 (1967), L115.CrossRefGoogle Scholar
[12]Gleeson, L. J. and Webb, G. M., ‘Modulation and spectral redistribution of galactic cosmic-rays’, Proc. 14th Int. Conf. on Cosmic-Rays, Munich, 3 (1975), 893.Google Scholar
[13]Jokipu, J. R. and Parker, E. N., ‘On the convection, diffusion and adiabatic deceleration of cosmic-rays in the solar wind’, Astrophys. J., 172 (1970), 319.Google Scholar
[14]Lie, S., ‘Über die Integration durch bestimmte Integrale Von einer Klasse linearer partieller Differentialgleichungen’, Arch. Math., 6, (1881), 328.Google Scholar
[15]Muller, E. A. and Matschat, K., Über das Auffinden von Ähnlichkeitslösungen partieller Differentialgleichungssysteme, mit Anwendung auf Probleme der Stromungphysik, Mizellaneen der Angewandten Mechanik’, Berlin, (1962), 190.CrossRefGoogle Scholar
[16]Ovsjannikov, L. V., Gruppovye svoystva differentisialny uravneni, Novosibirsk (1962) (Group Properties of Differential Equations, translated by Bluman, G. W., 1967).Google Scholar
[17]Parker, E. N., ‘The passage of energetic charged particles through interplanetary space’, Planet. Space Sci., 13 (1965), 9.CrossRefGoogle Scholar
[18]Parker, E. N., ‘The effect of adiabatic deceleration on the cosmic-ray spectrum in the solar system’, Planet. Space Sci., 14 (1966), 371.CrossRefGoogle Scholar
[19]Slater, L. J., Confluent Hypergeometric Functions, Cambridge University Press, London (1960).Google Scholar
[20]Toptygin, I. N., ‘Direct and inverse problem of cosmic-ray propagation in interplanetary space’, Geomag. and Aeron., 13 (1973), 181.Google Scholar
[21]Webb, G. M., Steady-state cosmic-ray propagation in interplanetary space, Ph.D. Thesis, University of Tasmania, Hobart, (1976).Google Scholar
[22]Webb, G. M. and Gleeson, L. J., ‘Monoenergetic-source solutions of the steady-state cosmic-ray equation of transport’, Proc. 13th Int. Conf. on Cosmic-Rays, Denver, (University of Denver), Conf. Papers, 5 (1973), 3253.Google Scholar
[23]Webb, G. M. and Gleeson, L. J., ‘Solutions of the cosmic-ray equation of transport’, Proc. Astron. Soc. Aust., Vol. 2, No. 5, (1974), 299.CrossRefGoogle Scholar