Operation of an intense ion beam diode at high repetition rate

Abstract

A magnetically insulated ion diode with a plasma anode has been operated on a pulsed power system capable of up to 1-kHz repetition rate in bursts of a few pulses. The authors discuss results on diode operating characteristics as a function of anode plasma parameters and insulating magnetic field strength and results on ion beam extraction in single-shot mode. The plasma anode ion source originates as an annular puff of H/sub 2/, C/sub 2/H/sub 2/, or other gas, which is preionized and then inductively broken down by a 1- mu s-risetime magnetic field coil. The plasma is then magnetically driven toward a magnetically insulated high voltage gap. Ion diode operation depends critically on the gas puff pressure and the relative timing between initiation of the main plasma driver pulse and the arrival of the high-voltage pulse at the ion diode. Single-shot and high-repetition-rate results have been compared, and the dependence of diode operation on other diode conditions (e.g. gas puff pressure and magnetic insulation field strength) has been investigated. Anode plasma temperature and density have been measured in hydrogen plasmas using spectroscopic techniques.<>