Spatial Landau damping in plasmas with three-dimensional κ distributions -: art. no. 052101

The increase in linear Landau damping in kappa-distributed plasmas compared to thermal equilibrium plasmas is studied by solving a boundary value problem for the spatially damped plasma waves generated by a planar grid electrode with an applied time harmonic potential. Solutions are computed for the plasma potential versus the distance from the electrode for different values of the parameter kappa skappad. The velocity parameter v(0) of the distribution function is chosen so that, as the parameter kappa varies, the kinetic temperature of the plasma remains constant. The exact solutions of this problem are also compared to approximate solutions derived from the theory of normal modes, that is, from the roots of the dispersion relation. This model problem demonstrates the significant increase in Landau damping by electrons which occurs for small values of the parameter kappa. (c) 2005 American Institute of Physics.