Effect of wave localization on plasma instabilities

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

OSTI ID:5591265

Levedahl, W K

The Anderson model of wave localization in random media is invoked to study the effect of solar-wind density turbulence on plasma processes associated with the solar type-III radio burst. ISEE-3 satellite data indicate that a possible model for the type-III process is the parametric decay of Langmuir waves excited by solar-flare electron streams into daughter electromagnetic and ion-acoustic waves. The threshold for this instability, however, is much higher than observed Langmuir-wave levels because of rapid wave convection of the transverse electromagnetic daughter wave in the case where the solar wind is assumed homogeneous. Langmuir and transverse waves near critical density satisfy the Ioffe-Riegel criteria for wave localization in the solar wind with observed density fluctuations {approximately}1%. Computer simulations using a linearized hybrid code show that an electron beam will excite localized Langmuir waves in a plasma with density turbulence. An action-principle approach is used to develop a theory of nonlinear wave processes when waves are localized. A theory of resonant particles diffusion by localized waves is developed to explain the saturation of the beam-plasma instability.

• Research Organization: California Univ., Berkeley, CA (USA)
• OSTI ID: 5591265
• Country of Publication: United States
• Language: English

Related Subjects

640104 -- Astrophysics & Cosmology-- Solar Phenomena
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107 -- Fusion Energy-- Plasma Research-- Instabilities
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BEAM-PLASMA SYSTEMS
COMPUTERIZED SIMULATION
ELECTROMAGNETIC RADIATION
ENERGY-LEVEL TRANSITIONS
EXCITATION
INSTABILITY
PLASMA DENSITY
PLASMA INSTABILITY
PLASMA WAVES
RADIATIONS
RADIOWAVE RADIATION
SIMULATION
SOLAR ACTIVITY
SOLAR RADIO BURSTS
SOLAR WIND
TURBULENCE