Miniature High Density Scandate Cathodes For Linear Beam Devices

This proposal describes a program for an improved impregnated dispenser cathode. It will first seek to verify and understand recent improvements in scandate cathodes by workers in China.To do this, it will conduct tests on these cathodes and it will study composition and fabrication procedures. Based on this, scandate cathodes of similar composition will be fabricated and tested. They will be incorporated into a miniature cathode format for use in high frequency amplifiers. Present impregnated cathodes cannot reliably exceed 10 amps/cm2 and 50,000 hours. But the Chinese have reported 100 amps/cm2 on scandate cathodes and these results have been verified in this country. This is a major breakthrough in cathode technology. The cathode is currently the main performance limiting component in linear beam amplifiers. Bandwidth, frequency, power and life are all adversely impacted by this limitation.