LONG LIFE COLD CATHODE STUDIES FOR CROSSED-FIELD TUBES
Abstract
The objective of the present cold cathode study program is to achieve long life cold cathode performance for crossed-field amplifiers. A 200A boron nitride film on a molybdenum substrate was subjected to electron bombardment at 0.16 A/cm sq and 1.2 kv for 3 hours and as a result delta max decreased from 1. 75 to 1.55. The high stress Electron Bombardment Vehicle was operated at 4A/cm sq. and 2.5 kv and the polished copper target showed thermal etching effects. Two 4-1-1 barium-calcium-aluminate impregnated tungsten samples were subjected to electron bombardment at varying current levels at 1.2 kV energy, corresponding to a average current densities of 0.2 and 0.4 A/cm sq for 23.5 and 19 hours respectively. Delta max levelled off to an asymptopic value of approximately 2.2 to 2.3 for both samples. Cathode emission life test of model No. 8A was terminated after 58 hours. This model was rebuilt as No. 8B with a 1. 680 inch diameter aluminum cathode. Other design changes were also incorporated and this tube has been designated for long life cathode emission evaluation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1967
- Accession Number
- AD0821609
Entities
People
- L. Lesensky
- M. Arnum
Organizations
- RTX