Influence of strong self-electric fields on the ion resonance instability in a nonneutral plasma column

Journal Article · Tue Nov 01 00:00:00 EST 1977 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.861813· OSTI ID:7209544

Davidson, R C; Uhm, H

The influence of strong self-electric fields on the ion resonance instability is examined for a cylindrical nonneutral plasma column immersed in a uniform axial magnetic field B/sub 0/e/sub z/. The analysis is carried out within the framework of a macroscopic cold-fluid model, and electrostatic stability properties are investigated for the case of rectangular electron and ion density profiles. The parameter delta= (2..omega../sup 2//sub p e//..omega../sup 2//sub c e/) (1-f) is introduced as a convenient measure of the relative strengths of the equilibrium self-electric force and the magnetic force on an electron fluid element. (Here, omega-circumflex/sub p e/ is the electron plasma frequency, ..omega../sub c e/ is the electron cyclotron frequency, f=n/sup 0//sub i//n/sup 0//sub e/ is the fractional charge neutralization, and delta=1 corresponds to the maximum allowed charge density for radial confinement of the equilibrium configuration.) An important conclusion of this study is that the equilibrium self-electric field can have a large influence on stability behavior. In particular, stability properties for delta9 or approx. =1 differ substantially from those obtained when deltavery-much-less-than1. Moreover, for nonneutral plasma column with significant charge neutralization, it is found that the fundamental mode (l=1) is not the most unstable mode. Rather, higher harmonic perturbations have larger growth rates. However, in the limiting case where fvery-much-less-than1 and deltavery-much-less-than1, the l=1 mode can have the largest growth rate, which is consistent with the result previously obtained by Levy, Daugherty, and Buneman.

• Research Organization: Division of Magnetic Fusion Energy, Energy Research and Development Administration, Washington, D. C. 20545
• OSTI ID: 7209544
• Journal Information: Phys. Fluids; (United States), Vol. 20:11
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
EQUILIBRIUM PLASMA
ELECTRIC FIELDS
ION WAVE INSTABILITY
CYLINDRICAL CONFIGURATION
DISPERSION RELATIONS
EIGENVALUES
ELECTRON DENSITY
LANGMUIR FREQUENCY
MAGNETIC FIELD CONFIGURATIONS
PLASMA DENSITY
CONFIGURATION
INSTABILITY
PLASMA
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
700107* - Fusion Energy- Plasma Research- Instabilities