The article presents recent results of the dramatically enhanced electric breakdown strength observed in the accelerating gap of a plasma-filled optical system for the formation and focusing of a wide-aperture pulsed electron beams with currents up to 80 A and energies up to 35 keV. This system is a plasma-optical diode type device in which the acceleration and formation of the electron beam occurs in the double layer between the emissive surface of the plasma cathode (electron emitter) stabilized by a fine mesh grid and the open surface of the anode plasma. The anode plasma is created by the toroidal plasma generator of original design based on the ion source with closed drift of electrons with an anode layer.