Increasing Electric field Standoff Between Conductors in Vacuum

Summary form only given. There are limits on the electric field that can be maintained in vacuum between conductors. Transporting a beam in vacuum using magnetic insulation is a solution on low impedance systems. On higher impedance systems the fundamental limitation is the breakdowns initiated initially by field emission followed by a vacuum arc. Field emissions require an electric field of about 10⁹ V/M. Actual vacuum breakdowns typically occur at electric fields of 10⁷ V/M or less. Techniques have been developed to condition surfaces to withstand considerably higher electric fields. These techniques have been used on systems ranging from pulsed power systems to miniature DC X-ray tubes to high voltage DC ion implanters. These applications will be described.