Plasma Motion Across Magnetic Fields

The analysis of plasma flow problems in magnetic fields is usually based on a hydromagnetic fluid model. In low‐density collisionless plasmas, however, the limitations of the applicability of this method are not clearly understood. In this paper a simplified self‐consistent field method is used, with particle motion considered in the guiding center approximation. In this case the high ``dielectric constant'' of the magneto‐plasma plays the role of the infinite conductivity of the fluid model. Several experiments are analyzed on the basis of this model, and the limitations and shortcomings of the hydromagnetic treatment discussed.