A new type, long focal length, 600 keV, continuous high current density accelerator is described. Beam focus is obtained from a combination of five magnetic and electrostatic lenses. The construction and preliminary multimomentum operation are outlined, wherein a total current of 80 mA at a current density of approximately 40 mA/cm2was obtained. A simple theory for maximum focused beam current density is developed for semispace charge‐neutralized machines which compares favorably with the experimental results. Problems such as back‐streaming electrons and required vacuum conditions are discussed. Focus and beam optics are considered for simultaneous acceleration of a multicomponent beam composed of the several molecular ions of normal hydrogen and of a hydrogen‐deuterium mixture.