Field Emission Cathode and Vacuum Microelectronic Microwave Amplifier Development

摘要

The objective of this report is to summarize progress, indicate problem areasthat have been addressed, outline plans for future work, and to discuss, in a realistic manner, the likelihood that the proposed work will be completed in a reasonable time frame. Although we knew that the growth of the ZrO2. Y2O3-W (ZYW) composite was far from an exact science, we felt that we could build on prior work in this area and make rapid progress toward solving some problems. However, a few of these problems, particularly that of banding in the structure (discontinuities in the growth of the tungsten fibers) proved to be more recalcitrant than expected. Nevertheless, an adequate amount of material with continuous fiber growth has now been made to fabricate a sufficient supply of samples to complete the proposed work. The composite growth work is discussed. Etching of the composites also proved more difficult than anticipated. Plasma etching was investigated, which may eventually provide better, and more uniform, pin tip geometries than were ever available with the chemical etches. LVFE structure development is recounted. Most of the work on emission testing has been associated with the set-up of a vacuum test station, design and assembly of a test vehicle, and collection of the associated electrical equipment needed for both the CW and RF electrical tests of the field emission cathodes.