RESEARCH, DEVELOPMENT, AND FABRICATION OF TUNNEL EMISSION CATHODES,
Abstract
Research was continued on the development of tunnel emission cathodes. Emission currents up to 300 microamperes were measured from Al-Al2o3-Au sandwiches with an area of lmm sq. In terms of current density, this corresponds to 30 ma sq. cm. The transmission coefficients at these current levels were of the order of 10 to the -3rd power and the peak film currents were usually in the 100-150 ma range. Several sand wiches were operated under pulsed conditions up to 30 hours without burnout at peak film currents of 10-20 ma and with peak emission currents of 10-20 microamperes. Several different metals have been evaporated for accelerator layers on the Al-Al2o3 system but none appeared to give the high reproducibility attained with gold. Experi ments were conducted to form an aluminum oxide layer bygaseous anodization. Emission currents up to 5 microamperes have been obtained from Al-Al2o3-Au sandwiches in which the oxide was formed by using this technique but burnout oc cured at about 30 ma of film current. Mass spec trometric analysis indicated that a high concen tration of impurities was present in the oxygen supply which probably contaminated the oxide layer. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1963
- Accession Number
- AD0413856
Entities
People
- J.w. Hall
Organizations
- General Electric