High Current Density Cathodes for Future Vacuum Electronics Applications; Final rept. 1 Aug 2007-30 Apr 2008

摘要

This final report summarizes the achievements at Calabazas Creek Research, Inc. and Massachusetts Institute of Technology to develop and demonstrate techniques for fabricating high current density cathodes using scandium to lower the emission work function. Several techniques were investigated for depositing scandium on and beneath the surface of cathode emitters with techniques for replenishing that removed by normal surface erosion processes. Results indicate that several techniques can successfully provide the initial deposition and subsequent replenishment for long lifetime operation. The techniques use readily available fabrication capabilities. A photonic band gap traveling wave circuit was designed compatible with an electron gun incorporating the high current density capability. Such a device would demonstrate the effectiveness of scandate cathodes in typical RF sources.