Characteristics of diode perveance and vircator output under various anode-cathode (A-K) gap distances

When the electron beam is generated from the cathode, the electrode sheath plasma is also generated, and hence the perveance of diode is being varied to change the diode output characteristics. In our pulsed power system "Chundoong", the perveance characteristics have been experimentally investigated, from which the sheath plasma expansion speed has been found to be an about 3 cm//spl mu/s inside the diode. It is shown inside the diode that the sheath plasma expansion gives the influence on the electron beam current density, The Vircator microwave output has been shown to be dependent especially on A-K gap distance of which initial 4 mm in A-K gap distance is found to be optimized for maximum power.