Premium
A Linear Analysis of The Formation of Field‐Aligned Striations in Plasma Clouds Due to Cross‐Field Instability
Author(s) -
Rao P. B.,
Russell W. H.
Publication year - 1971
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/rs006i002p00221
Subject(s) - instability , plasma , electric field , two stream instability , ionization , physics , striation , atomic physics , magnetic field , computational physics , materials science , ion , mechanics , quantum mechanics , composite material
A weakly ionized plasma with gradients in the ionization density under the influence of the crossed electric and magnetic fields is subject to a unique type of plasma instability called the cross‐field or E×B instability. This paper examines by means of a linear analysis the relevance of such an instability mechanism to the formation of the field aligned columns of enhanced ionization or striations in the artificially generated plasma clouds in the upper atmosphere. A Gaussian model for the electron density distribution in the cloud and the electric fields that have been derived from the ion and neutral cloud drift motions have been used in computing the characteristic parameters, which are the minimum wavelength λ min and the e ‐folding growth time τ for the instability. A brief comparison has shown good agreement between the computed instability model and the observed striation formation in one of the high latitude Barium releases conducted in Alaska during March 1969 (test hemlock of Secede III series). Some general results that show the dependence of the instability parameters on the height of the release and cloud dimension are also presented.