Production of Ions by Repetitive Breakdown of a Vacuum Gap

Zinc ion pulses with varying amplitudes up to 1 mA have been extracted from a vacuum discharge. Repetitive operation of the pulsed discharge at 5300 Hz was maintained for 24 min. Breakdown of the 0.4 mm vacuum gap was accomplished by ramp-charging a 270 pF capacitor connected across the gap until breakdown occurred, the capacitor then being discharged through the gap. Stable operation was maintained by feedback control of the electrode spacing. The anode was eroded at 10 mg/C by the discharge, with 65 percent of the anode material being deposited on the cathode in the form of a fiber.