Landau Damping of Electron Plasma Waves in the Linear and Trapping Regimes
Abstract
Linear Landau damping and nonlinear wave-particle trapping oscillations are observed with m(sub theta) = 0 standing plasma waves (Trivelpiece-Gould modes) in a trapped pure electron plasma. The measured linear damping rate (10 (exp -3 </^gamma/omega </^ 10 (exp -1) agrees quantitatively with Landau damping theory for moderate plasma temperatures (1 < T < 3 eV), and exceedingly low wave amplitudes (delta n/n <10 (exp -6). At larger amplitudes, the wave initially damps at the Landau rate, then develops trapping oscillations at frequency ohm(sub tr), causing the effective damping rate to decrease with amplitude as first predicted by O'Neil in 1965. For comparison, the measured damping rate is observed to decrease dramatically when the resonant particles are eliminated by truncating the nominally Maxwellian velocity distribution.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 24, 2002
- Accession Number
- ADP012532
Entities
People
- C.. F. Driscoll
- Francois Anderegg
- James R. Danielson
- Kevin Rigg
- Nobuyasu Shiga
Organizations
- University of California, San Diego