Progress Report on Construction and Testing of a 3 MeV, DC, Ampere Intensity Electron Beam Recirculation System

Construction is underway on a 3 MV electrostatic accelerator designed to recirculate D.C. electron beams with intensities up to 4 amperes. The test facility includes a 3 MV, SF6 insulated vertical accelerator with parallel accelerator and decelerator tubes, diagnostic equipment, and vacuum and beam line components to bend the beam 180° and return it to the terminal. Special consideration has been given to cathode, electron gun, electron collector, and optical design to allow beam recovery efficiency of better than 99.99% at currents up to 4 amperes.