Resonant Alfven wave instabilities driven by streaming fast particles

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6821204

Zachary, A L

A plasma simulation code is used to study the resonant interactions between streaming ions and Alfven waves. The medium that supports the Alfven waves is treated as a single, one-dimensional, ideal MHD fluid, while the ions are treated as kinetic particles. The code is used to study three ion distributions: a cold beam; a monoenergetic shell; and a drifting distribution with a power-law dependence on momentum. These distributions represent: the field-aligned beams upstream of the earth's bow shock; the diffuse ions upstream of the bow shock; and the cosmic-ray distribution function near a supernova remnant shock. Particles that interact with a single, monochromatic electromagnetic wave possess an additional constant of the motion. The field-aligned beams resonantly excites only a single mode, which saturates when the frequency of a trapping oscillation is comparable to the growth rate. The beam ions remain trapped by the wave until decorrelation. After decorrelation, the particles appear to have a Maxwellian distribution, but the additional constant of the motion contrains their motion in phase space. When many modes are present, the wave-particle interactions are usually described using quasilinear theory. The drifting shell resonantly excites many modes. The cosmic-ray distribution functions simulations are used to observe the spatial diffusion caused by pitch-angle scattering.

• Research Organization: California Univ., Berkeley (USA)
• OSTI ID: 6821204
• Country of Publication: United States
• Language: English

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71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALFVEN WAVES
BEAMS
COSMIC RADIO SOURCES
COSMIC RAY PROPAGATION
DISTRIBUTION FUNCTIONS
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
FLUID MECHANICS
FUNCTIONS
HYDRODYNAMICS
HYDROMAGNETIC WAVES
INSTABILITY
INTERACTIONS
ION BEAMS
ION WAVE INSTABILITY
MAGNETOHYDRODYNAMICS
MECHANICS
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
RADIATION STREAMING
SUPERNOVA REMNANTS
TRAPPING