150 kA fibre pinch experiments with pre-pulse

Experiments investigating the effects of a pre-pulse on a fibre Z-pinch are currently being performed on the IMP-Generator. Although there have been a number of experiments in which Z-pinches have been reported to show more stability, the stabilising mechanisms remained controversial. In order to clarify one of the existing hypotheses of experimental pinch stabilisation a small pre-pulse Marx generator (PPM) has been fitted onto the IMP-Generator to produce an adjustable current pre-pulse reaching a 3-6% peak of the main pulse. The PPM discharges are investigated with a set of optical and electrical diagnostics in two different output regimes. All pre-pulsed discharges of IMP were performed with the pre-pulse starting about 1.5 μs before main current pulse. A few nonpre-pulsed discharges were carried out for reference. The load was in all cases a 7 μm carbon fibre across an 18 mm cathode-anode gap