STUDIES OF VACUUM BREAKDOWN BETWEEN MICRON-SIZED AREAS.
Abstract
Vacuum breakdown between broad-area electrodes is initiated and occurs in localized areas of the electrodes. A new method of investigating such localized areas with a modified 'Muller' microscope is described and results are discussed. The method consists of scanning a metal surface with a small-area electrode (anode) at constant current and constant voltage. In this manner a plot of the cathode surface is obtained and micron-sized inhomogeneities can be detected. The experimental results indicate that changes of the electrodes occur even at current levels of 10 to the -10th power amperes when the surface is scanned for the first time. Apparent inhomogeneities of the cathode surface can be created or destroyed by current pulses of microamperes. Using the Fowler-Nordheim equation for the analysis of the emission data, it was found that the field enhancement factor is a function of gap spacing, that the field enhancement factor can change slightly at current levels of 10 to the -10th power amperes and can change drastically at current pulses of a few microamperes. The latter current pulses are usually accompanied by pressure increases. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1966
- Accession Number
- AD0634761
Entities
People
- Hans Hieslmair
Organizations
- United States Army Communications-Electronics Command