High intensity, pulsed electron beam emission from carbon nanotube cathodes

High intensity electron emission cathodes based on carbon nanotube films have been successfully fabricated by use of a screen printing method. The emission properties of the cathode were investigated in single-pulse and double-pulse modes. The high intensity emission from the cathode is obtained and the highest emission current density reaches 267 A/cm2 at an electric field of 15.4 V/μm in double-pulse mode. Emission images of the cathode surface prove that the plasma layer forms on the cathode surface, and the production mechanism of the high-current electron beams is explosive electron emission. This carbon nanotube cathode appears to be suitable for high-power microwave device applications.