Effect of Coulomb Collisions, Landau Damping and Particle Trapping on Linear and Nonlinear Ion Aooustic Waves.
Abstract
The general propagator expansion method is used for the study of the collision effects and the Fokker-Planck kinetic equation is employed for several collisional processes. In drift-free plasma, the studies show that the plasma may become unstable if e-i collision growth can overcome Landau damping and other collision damping. The contamination can affect ion acoustic waves significantly and a small amount of light ion contamination can cause much higher damping. For our experiment on the ion acoustic waves in drift-free plasma, the experimental results are explained with the consideration of collision and contamination effects and are close to our theoretical results.For a plasma with a quasi-static electric field, two ion acoustic modes may propagate in a single ion species plasma. This ion-acoustic instability associated with the slow mode is a kinetic instability and is caused by the interaction of ions and electrons. In our experiment, the fast mode is found and the measured results agree with the theoretic values. In a two-on-species plasma, the velocity differences between the ion species can cause the ion-ion two-stream instability. This is a fluid instability and only exists in a range of ion drift velocities and wave frequencies. An experiment was performed to study ion-ion two-stream instability. The unstable waves generated by the ion beams are observed as predicted by theory and coincide with the kinetic dispersion relations for the ion-ion two stream instability.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 30, 1996
- Accession Number
- ADA315316
Entities
People
- Chung Chan
Organizations
- Northeastern University