THE METAL VAPOR VACUUM ARC (MEWA) HIGH CURRENT ION SOURCE*

An ion source is described in which a metal vapor vacuum arc is used to create the plasma from which the ions are extracted. Beams of a variety of ions have been produced, ranging from lithium up to uranium. At an extraction voltage of 25 kV we’ve measured an ion beam current of over 1 Ampere, with over 550 ema of the beam in an emittance of 0.0731 cm. mradians (normalized). The ion charge state distribution varies with cathode material and with arc power; for uranium a typical distribution is peaked at U5 +, with up to 40 % of the beam current in this charge state