Two-dimensional electrostatic E Vector x B Vector trapping

Abstract

The nonlinear motion of a charged particle in a uniformly magnetized, two-dimensional plasma is analyzed in the presence of finite amplitude electrostatic waves traveling in the plane perpendicular to the magnetic field. In a strongly magnetized plasma, no particle trapping occurs in a single electrostatic traveling wave of arbitrary amplitude, since the induced E Vector x B Vector motion is orthogonal to the direction of wave propagation. However, particle orbits can be trapped when there are at least two mutually orthogonal components of the electrostatic field with finite wave amplitude E/sub perpendicular/B greater than or equal to ..omega../k/sub perpendicular/ such that a particle drifts one wavelength in a wave period. This threshold amplitude for strong nonlinear behavior coincides with and helps to explain the many-wave turbulence criterion for the onset of particle diffusion in a two-dimensional plasma.