THERMIONIC EMISSION FROM METAL CRYSTALS IN ALKALI METAL VAPORS
Abstract
Thermionic emission microscopes were used to evaluate the emission density from tungsten, molybdenum, tantalum, niobium, nickel, rhenium, and niobium carbide in cesium, rubidium, and potassium vapors as a function of alkali vapor pressure, emitter temperature, and emitter crys tal face. It was found that when the emitter surface had less than a monolayer coverage of alkali metal, it was the atomically closest packed plane of the emitter which yielded the highest thermionic emission density. The effects of surface contaminants were studied and evidence was obtained suggesting that the high work func tion of the 112 plane of tungsten and molybdenum may be caused by a contaminant. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1963
- Accession Number
- AD0407962
Entities
People
- H. F. Webster
- P. L. Read
Organizations
- General Electric