Stability of Positive Column in a Strong Magnetic Field

抄録

The instability of positive column is investigated theoretically, under the assumption that the densities of electrons and ions are perturbed independently. The electric field induced by these perturbations is derived exactly by solving Poisson’s equation. For helical perturbations, the existence of a finite potential at the wall is found. A relation between the critical magnetic field above which the perturbation is unstable and the corresponding electric field is obtained. It depends upon the discharge current; and this dependence is in good agreement with Hoh and Lehnert’s experiments.