Electron gun with a photocathode for electron-beamcontrolled lasers

An investigation was made of the possibility of using a photocathode and a pulsed light source in an electron gun to generate a high-current electron beam of large cross section and a uniform distribution of the current density. A gun of this kind could also have facilities for controlling the duration and shape of the electron pulses and for controlling the current density while keeping the gun voltage constant. A photoemission current of ~20A/cm² density was obtained from a magnesium photocathode. A gun of this kind which was found to be suitable for electron-beam-controlled lasers was demonstrated.