Premium
Computation of Dispersion Curves for a Hot Magnetoplasma with Application to the Upper‐Hybrid and Cyclotron Frequencies
Author(s) -
Muldrew D. B.,
Estabrooks M. F.
Publication year - 1972
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs007i005p00579
Subject(s) - physics , dispersion relation , computational physics , electron , plasma , collision frequency , whistler , magnetic field , plasma oscillation , refractive index , wavenumber , atomic physics , optics , quantum mechanics
Rapid calculations of the dispersion relation can be made for a hot, Maxwellian electron magnetoplasma, with collisions and for any angle β between the wave normal and static magnetic field without using the low‐temperature or the quasi‐static approximations. The dispersion equations of Lewis and Keller [1962] are discussed and interpreted for the purpose of computer programming; these equations are valid for a Vlasov‐Maxwellian plasma and contain a particle‐preserving collision term. Examples of dispersion curves for homogeneous plane waves show: (1) protrusions from some refractive‐index surfaces and (2) the usual multiplicity of solutions for a Maxwellian plasma when the real and imaginary components of the refractive index are of similar magnitude. For a wave frequency 1.11 times the plasma frequency and about 1.78 times the gyrofrequency, a minimum is found in the collisionless damping at β = 0° and a maximum is found at about β = 14°. Three alternatives for the gyroresonance observations on topside ionograms can be found from a study of the dispersion curves near the gyrofrequency: (1) an energy transfer between the highly damped whistler mode and electrons in the vicinity of the sounder, (2) the field resulting from the multiplicity of solutions mentioned above, and (3) an evanescent field.