Electron transport in multiple orifice hollow cathodes
Abstract
The effect of keeper geometry on the transport of electrons is investigated experimentally using electrostatic probes in the plume of a hollow cathode. Three keeper configurations—one single orifice and two multiple orifices—were studied. The multiple orifice cases were chosen to examine the influence of the hole-pattern radius while the total exit area and the number of holes remained constant. Two-dimensional maps of the plasma parameters and wave properties were inferred from the probe measurements and were used to evaluate a generalized Ohm’s law for the electron flow field. The contributions of pressure, fields, and drag on the transport of electrons were analyzed. The results indicate that increasing the hole-pattern spread reduces the electric field in the plume and increases the pressure contribution to the transport. A further analysis of turbulent wave energy conservation indicates that the multiple orifice keepers increase ion-neutral collisional damping, similar to auxillary flow injection. The implications of these findings on cathode plume modeling and keeper design are discussed.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 28, 2021
- Source ID
- 10.1063/5.0066894
Entities
People
- M S McDonald
- Marcel P. Georgin
Organizations
- United States Naval Research Laboratory