Stability and operating characteristics of the applied B proton extraction diode on KALIF

In this paper we describe detailed investigations of the stability ami operating characteristics of a magnetically insulated proton beam diode in extraction geometry developed for the 1 TW, 1.7 MV pulsed power generator KALIF. From an analysis of ion current density fluctuations the frequency spectrum of predominant instabilities has been determined. Although late in the pulse the main frequencies (1.2 GHz) are higher than expected they are compatible with an ion transit time mode. Combining the results from various detectors we suggest that the parallel load observed in our diode is probably due to a loss of low energy electrons into the expanding anode plasma.