Coaxial cold-cathode magnetron

We have studied the experimental prototype of an X-band pulsed coaxial magnetron (CM): τ = 70 ns; F = 1000τ/s. The above magnetron uses a metalporous secondary-emission cathode (SEC) as a set of rings between the discs made of refractory metal are placed, with the blade-like shoulders being periodically arranged around their edges. For tunneling the required excitation current from the field emitter (FE) the value of the electric field strength (E_ef) should be around 10⁷ V/cm . But at an anode voltage of 5 to 10 kV, E_ef is two orders of magnitude less than is required. The normal operation of the magnetron prototype is based on 1) the results from the theoretical and experimental studies into the configuration of field emitters; 2) the selection of their material ensuring an increase in E_ef on the top of blade-like shoulders up to ∼10⁷ V/cm and 3) FE activation using the active SEC substance. In the course of experiments one could observe reliable generation of stable oscillations in a short-pulse mode of the operating CMs. For an 8 kV anode voltage the CM output pulse power of over 10 kW at 25% efficiency is provided.