Characteristics of UC, ZrC, and (ZrC) (UC) as Thermionic Emitters

Abstract

Uranium carbide is found to have the property of high thermionic emission in the observed temperature range from 1400 to 1800°K. The parameters of the Richardson equation which can be used to fit the data are A=7.3×105 amp/cm2 (°K)2 and φ=4.57 v. While these parameters accurately predict the observed saturated currents, it is doubtful that such anomalous values are of theoretical significance within the framework of the Richardson-Dushman derivation. A solid solution form of uranium carbide and zirconium carbide gives substantially the same thermionic emission as uranium carbide, and for other reasons appears to be the more useful emitter. The carbides require no surface preparation or activation schedule for use as emitters.

Noise Transformation and Cyclotron Waves in Crossed Fields

“…1 the component ac Lorentz equations are developed as follows after separating out and dropping the dc terms: (1) and…”

Materials Problems in Cesium Thermionic Converters

“…The selection of cathode materials is greatly hampered by our lack of information on the physical and chemical properties of materials at temperatures higher than 1000~ Present-day cathode materials are chosen mainly on the basis of their melting points and their electron emission properties. They include tungsten (2-4), thoriated tung- sten (2), tantalum (1), molybdenum (5,6), ZrC (1, 7), UC (7), and UC-ZrC (1, 7) solid solutions. All of these materials have melting points higher than 2400~…”