The nonlinear diocotron mode in a pure electron plasma
نویسنده
چکیده
The nonlinear diocotron mode, discussed by Fine, Driscoll, and Malmberg @Phys. Rev. Lett. 63, 2232 ~1989!# is characterized by two equations, one describing the frequency of orbiting, the other giving the quadrupole moment, as functions of size and offset. A new analysis, based on the method of moments, which yields equations more general in their content, is presented here. For example, the new equations describe columns whose shapes are not elliptical and whose densities are not constant. © 1996 American Institute of Physics. @S1070-664X~96!01409-7#
منابع مشابه
Diocotron and Kelvin mode damping from a flux through the critical layer.
Experiments and theory characterize a novel type of spatial Landau damping, caused by a flux of particles through the wave or rotation resonance (critical) layer. Pure electron plasma experiments demonstrate that a steady flux of particles causes algebraic damping of diocotron mode amplitudes for azimuthal modes m = 1 and m = 2, and a simple model of dynamics in the nonlinear cat's eye clarifie...
متن کاملDiocotron Wave Echoes in a Pure Electron Plasma
Experimental images illustrate spatial Landau damping of an externally launched diocotron mode, and the resulting echo from a second externally launched wave. Filaments at the resonance layer exhibit spiral wind-up during the collisionless damping process, and “unwind” during the echo formation.
متن کاملResonant drift-wave coupling modified by nonlinear separatrix dissipation.
Resonant drift-wave coupling experiments characterize a new dissipative coupling term caused by a trapping separatrix. The system is a cylindrical pure-electron plasma with an axial trapping separatrix generated by an applied theta-symmetric wall voltage. The resonant decay of m_{theta}=2 diocotron modes into m_{theta}=1 trapped-particle diocotron modes is measured and compared to parametric mo...
متن کاملSimple theory of a nonlinear ciiocotron mode
A simple perturbation theory of the frequencies and density distortions of the I= 1 diocotron mode on pure electron plasma columns is presented. This mode is the dynamical state of an off-axis electron column which is orbiting around the containment axis at the ExB drift velocity. The theory predicts shifts in the orbit frequency and quadrupole distortions of the plasma surface, both varying as...
متن کاملExponential growth of an unstable l=1 diocotron mode for a hollow electron column in a warmfluid model
Numerical investigations of a warm-fluid model with an isothermal equation of state for the perpendicular dynamics of an axisymmetric, magnetically confined pure electron plasma predict an exponentially unstable, I= 1, diocotron mode for hollow density profiles. , The unstable mode can be identified with a stable, nonsmooth mode that exists in cold drift models but which is destabilized-by fini...
متن کامل