Accession Number : AD0437273


Title :   RESEARCH, DEVELOPMENT, AND FABRICATION OF TUNNEL EMISSION CATHODES.


Descriptive Note : Final interim technical rept. July-Nov 63,


Corporate Author : GENERAL ELECTRIC CO OWENSBORO KY


Personal Author(s) : Hall,J W


Report Date : Nov 1963


Pagination or Media Count : 68


Abstract : Metal-insulator-metal (M-I-M) sandwiches have been studied as an electron source for possible use as a cathode in electron tubes. The M-I-M sandwich, which had an area of .01 sq. cm, consisted of an aluminum base layer, a thin layer of AL203, and a thin metal accelerator layer. The metal films were formed by vacuum evaporation, while the Al203 was formed by either solution anodization, gaseous anodization, thermal oxidation or evaporation of Al in an oxygen atmosphere. The best results were obtained by solution anodization in a 5% solution of tartaric acid. Twelve metals were investigated as accelerator layers for the Al-Al203 system with the most promising results obtained with gold. Experimental results are reported. The sandwiches were tested under both pulsed and D.C. conditions. Under D.C. conditions the heat energy generated caused the accelerator films to agglomerate, the oxide to break down, and promoted reactions between the films. Under pulsed conditions, with less average heat generated, the sandwiches operated at emission current densities of 200 ma/sq. cm for short periods and at low emission current densities for periods up to 100 hours with no apparent signs of degradation. (Author)


Descriptors :   *CATHODES(ELECTRON TUBES) , *TUNNELING(ELECTRONICS) , TUNNELING(ELECTRONICS) , METALS , MANUFACTURING , PRODUCTION , SANDWICH CONSTRUCTION , DIELECTRICS , ALUMINUM , ALUMINUM COMPOUNDS , OXIDES , VAPOR PLATING , VACUUM APPARATUS , TEMPERATURE , EMISSIVITY , HEAT , FAILURE(MECHANICS) , ELECTRON MICROSCOPY , ELECTRON DIFFRACTION


Distribution Statement : APPROVED FOR PUBLIC RELEASE