Accession Number : AD0715882

Title :   Electrostatic Electron Oscillations in Cylindrical, Non-Neutral Plasmas.

Descriptive Note : Research rept.,

Corporate Author : AVCO EVERETT RESEARCH LAB EVERETT MASS

Personal Author(s) : Linson,Lewis M.

Report Date : SEP 1970

Pagination or Media Count : 34

Abstract : The character and stability of electrostatic electron waves which propagate both parallel to B (wavenumber beta) and perpendicular to B (azimuthal mode number l) in non-neutral plasmas in cylindrical geometry are studied. The background ions are taken to be infinitely massive and so provide a partial neutralization of the unperturbed electron space charge; this neutralization ranges from the completely unneutralized electron plasma case to the more familiar case of a completely neutral plasma. It is found that the axisymmetric mode (l = 0) is stable for arbitrary radial density variation when the charge density is not too high. For l > or = 1 and electron and ion densities constant out to r = a and zero beyond, the system is stable for all frequencies independent of the degree of neutralization and the location of a conducting outer wall. The dispersion relation is analogous to that for a neutral plasma permitting separate low and high frequency propagation bands. For low frequencies and low, nonincreasing electron, ion, and net charge densities, it is found that the presence of a resonant layer (zero frequency as seen by the electrons) within the electron cloud is necessary but not sufficient for instability. In general, finite axial wavenumber increases the tendency towards stability. (Author)

Descriptors :   (*PLASMA MEDIUM, ELECTROSTATIC FIELDS), MAGNETIC FIELDS, OSCILLATION, PLASMAS(PHYSICS), INTEGRAL EQUATIONS, BOUNDARY VALUE PROBLEMS, DIFFERENTIAL EQUATIONS, STABILITY

Subject Categories : Plasma Physics and Magnetohydrodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE