Quasi-directly heated cathode for magnetron

Quasi-directly heated cathode is the new version of the cathode design with vacuum gap for microwave heating magnetrons (Djubua, 1997). A characteristic feature of this design is that the spiral, on which the emission body is fixed as a bushing, performs three functions: firstly - the cathode holder, second - the heater, third - the source of primary electron which provide the magnetron fast start. The necessary spiral emission level is achieved due to adsorption of active metals vaporizing in the operation process from the cathode bushing.