Accession Number : AD0289539

Title :   RESEARCH OF CESIUM-VAPOR CELLS EMPLOYING CARBIDE EMITTERS

Corporate Author : GENERAL DYNAMICS SAN DIEGO CALIF GENERAL ATOMIC DIV

Personal Author(s) : CARPENTER,F. ; CHENEY,G.

Report Date : 31 OCT 1962

Pagination or Media Count : 1

Abstract : Emission poisoning can result when a UC-ZrC emitter is exposed to air after it has been heated to a high temperature. Suitable handling of the emitter after mechanical abrasion of the surface will completely remove the poisoned region and retore satisfactory emission behavior. It was established that thermionic emission from UC-ZrC emitters is largely independent of composition. However, UC-ZrC emitters with low mol-% UC composition are more readily poisoned than those with high mol-% UC compositions. Data on the vacuum thermionic emission of UC-ZrC solid solutions are consistent with the hypothesis that emission from UC and UC-ZrC emitters is controlled primarily by an adsorbed layer of uranium on the surface of the carbide. Work on the Mark I-D thermionic cell has produced a workable and versatile research cell. Initial operation at low temperatures revealed significant information concerning the thermionic effects of cesium on carbide surfaces. Consequently, cesium vapor adsorption causes a substantial modification of the thermionic work function of a carbide. (Author)

Descriptors :   *CARBIDES, *CESIUM, *THERMIONIC EMISSION, ABRASIVES, ADSORPTION, CHEMICAL ANALYSIS, ELECTRIC CURRENTS, ELECTRODES, HIGH TEMPERATURE, IMPURITIES, MIXTURES, SURFACES, URANIUM COMPOUNDS, VACUUM APPARATUS, VAPORIZATION, VAPORS, WORK FUNCTIONS, ZIRCONIUM COMPOUNDS

Distribution Statement : APPROVED FOR PUBLIC RELEASE