Dispersal of a Localized Density Fluctuation in a Uniform Magnetoplasma

Abstract

The dispersal of a localized density fluctuation in a uniform magnetoplasma is studied using the macroscopic fluid equations. Expressions are obtained for the Fourier‐Laplace transforms of the perturbed density, potential field, and flux distributions. These expressions are inverse transformed, using a combination of analytic and numeric techniques. The resulting curves which display the real space and time development of the system are then compared with magnetic‐field‐free ambipolar diffusion. One finds that diffusion along the magnetic field, $\text{θ\hspace{0.17em}=\hspace{0.17em}0°}$ , is much more rapid than ambipolar diffusion, that when the ion motion is not affected by the magnetic field, diffusion at $\text{θ\hspace{0.17em}=\hspace{0.17em}90°}$ proceeds at approximately the ambipolar rate, and that the electron and ion fluxes are not ambipolar.