Nonlinear saturation of the collisionless drift instability

Journal Article · Wed Jun 01 04:00:00 EDT 1977 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.861982· OSTI ID:7291348

Simon, A; Gross, L S

A collisionless spatially nonuniform plasma is considered in a finite conducting cylinder in a uniform magnetic field. The magnetic field is increased by a small fractional amount over the critical value for onset of instability. A single mode grows and is saturated by nonlinear effects. Analytic expressions are obtained for the time-asymptotic saturation amplitude and frequency shift. Indeterminate equations and singular functions are resolved by methods similar to those used earlier in the one-dimensional bump-on-tail analysis, and the form of the modified equilibrium distribution and potential is obtained. A specific numerical example demonstrates that saturation is due to increased ion Landau damping, and that this saturated amplitude is unstable to small deviations. Hence, the onset of the instability is predicted to be of the ''hard'' variety. This result holds both in the ''quasi-linear'' approximation and in the full nonlinear case.

• Research Organization: Department of Mechanical and Aerospace Sciences, University of Rochester, Rochester, New York 14627
• OSTI ID: 7291348
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 20:6; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
COLLISIONLESS PLASMA
CONFIGURATION
CYLINDRICAL CONFIGURATION
DRIFT INSTABILITY
INHOMOGENEOUS PLASMA
INSTABILITY
INSTABILITY GROWTH RATES
LOW-BETA PLASMA
MAGNETIC FIELDS
PLASMA
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES