Observations of a double-layer in a hot-cathode discharge

The meniscus region of a hot cathode discharge was selected for an analysis of the nonlinear interaction of a convectively amplifying wave with a background plasma. A potential step, resulting from rectification of the wave fields is observed, and it is noted that predicted values for the step are in good agreement with empirical data. Attention is given to the determination of plasma parameters (using a Langmuir probe placed in front of the cathode) in terms of their relation to the pondermotive force.