Electron gun for microwave tubes with cold field emitting cathodes

The latest achievements in technology of diamond-like carbon films deposition have made it possible to obtain emitters capable of operating in a technical vacuum with average current density 1-2 A/n/spl tilde/i/sup 2/ at macroscopic electric fields on the cathode 6-7 kV/mm. This discovers the opportunities of creation of new class of electron guns for industrial microwave tubes (TWTs, klystrons) having unique features: instant turn-on time, absence of heating power, high time of life, increased electrodes´ stability and absence of cathode sputtering.