Development of micro fabricated scandate dispenser cathode and electron gun for terahertz vacuum electron devices

Scandate dispenser cathode with hundreds of ampere per square centimeter has been developed using metal injection molding (MIM) technique for terahertz vacuum electron devices. We have investigated scandate thermionic cathode surface by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) before surface treatment. And then, scandate cathode was fabricated with 1 mm diameter. The performance was verified by beam transmission test after assembling electron gun using microfabricated scandate cathode. The beam transmission rate was 99.8% for 0.5 mm radius drift tube with 0.8 T magnetic field condition.