Initial Plasma Testing of the Ion Proportional Surface Emission Cathode
Abstract
The Ion Proportional Surface Emission Cathode (IProSEC) is a low-brightness cathode technology under development for applications where large areas are available for emission and it is advantageous to avoid the space charge effects associated with bright or intense sources. Space applications include spacecraft charge control and electrodynamic tethers. Surface Emission Cathodes emit electrons by concentrating an electric field between a p-doped insulating substrate and an adjacent metal cathode element. The substrate potential is held positive of the cathode with gate elements. In plasma, the gate is eliminated due to ambient ion flux which maintains the substrate potential near plasma ground. Prototype devices have been tested using a laboratory plasma source achieving sustained and stable operation over a wide bias voltage for a given ion flux. Chip-based sources are compared to carbon nanotube mats. The principle of operation, ion flux proportionality, and prototype performance is discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 15, 2008
- Accession Number
- ADA490909
Entities
People
- Adrian Wheelock
- D. L. Cooke
- Michael W. Geis
Organizations
- Air Force Research Laboratory