Accession Number : AD0480973

Title :   LONG-LIFE COLD CATHODE STUDIES FOR CROSSED-FIELD TUBES.

Descriptive Note : Quarterly rept. no. 1, 15 Oct 65-15 Jan 66,

Corporate Author : RAYTHEON CO WALTHAM MA MICROWAVE AND POWER TUBE DIV

Personal Author(s) : Lesensky, L. ; Das, D. K. ; McGeoch, C. R.

Report Date : APR 1966

Pagination or Media Count : 40

Abstract : The objective of this study is to investigate the feasibility of utilizing cold cathodes in high power crossed-field tubes (Including linear and reentrant types) with reliable long life, a minimum of 10,000 hours being required. The report deals with the investigation of candidate long life cathode materials. Two test vehicles were constructed, one for evaluating crossed-field amplifier performance and another for observing the effects of electron bombardment on secondary emission ratio sigma. Measurements of the secondary emission ratio as a function of primary energy have been made for a series of Mo - Al2O3 electron-beam-evaporated thin films of 100 A and 1000 A thickness on a Pt substrate with a range of evaporator source compositions of 10% Mo the 30% Mo. Results showed that sigma max = 2-3 which indicated no degradation of sigma had occurred due to the Mo component. The dependence of sigma on the angle of incidence for 25 A Al2O3 films on Al was also to be approximately proportional to the expected factor (cos theta - 1/2. Life-limiting factors of electron and ion bombardment present in crossed-field amplifiers are discussed. (Author)

Descriptors :   *CROSSED FIELD DEVICES), (*COLD CATHODE TUBES, (*ELECTRON MULTIPLIERS, COLD CATHODE TUBES), (*CATHODES(ELECTRON TUBES), SECONDARY EMISSION), ELECTRON IRRADIATION, MOLYBDENUM, ALUMINUM COMPOUNDS, OXIDES, ELECTRON BEAMS, ION BOMBARDMENT, DOPING, GALLIUM ALLOYS, ARSENIC ALLOYS, SEMICONDUCTORS, METAL FILMS, PLATINUM, MAGNETRONS.

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE