STABILITY OF AN INHOMOGENEOUS PLASMA IN A MAGNETIC FIELD

Journal Article · Sat Apr 01 04:00:00 EST 1961 · Physics of Fluids (U.S.)

DOI:https://doi.org/10.1063/1.1706356· OSTI ID:4049342

Lehnert, B

Charge separation caused by ion and electron clouds drifting with different velocities in the x direction is discussed. It is shown that a plasma region(1) of constunt density n(1- theta ) is initially divided from another region(2) of constant density n by a sharp sinusoidal boundary. The density gradient is then involved in the parameter 1- theta which vanishes in the earlier theory. For cases where theta << 1 the argument of the solution(1), which is valid in the initial phase (ut << L), is reduced by a factor ( theta /2)/sup 1/2/. This suppresses the growth rate considerably. When the separation ut becomes comparable with L the solutions are altered and a reversal of the electric drift may even take place. The shape of the ion and electron clouds can then be rep resented by a mixture of sinusoidal modes. A deduction similar to that by Rosenbluth and Longmire gives the space charge and the drift motions in terms of the perturbations. The stability of the system is determined by the parameter gamma . Oscillations with steadily increasing amplitude occur when gamma > 1/4, whereas the amplitude is limited for gamma < 1/4. Consequently, a strong magnetic field gradient provides a scrambling mechanism which smooths out the electric field drift and may stabilize the system, at least for small disturbances. (N.W.R.)

• Research Organization: Royal Inst. of Tech., Stockholm
• Sponsoring Organization: USDOE
• NSA Number: NSA-15-016583
• OSTI ID: 4049342
• Journal Information: Physics of Fluids (U.S.), Journal Name: Physics of Fluids (U.S.) Vol. Vol: 4; ISSN PFLDA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

DENSITY
DISTURBANCES
ELECTRIC CHARGES
ELECTRIC FIELDS
ELECTRONS
IONS
MAGNETIC FIELDS
MOTION
PHYSICS
PLASMA
SPACE CHARGE
STABILITY
SURFACES
VARIATIONS
VELOCITY