Stromverteilung und Materiemitführung bei der Hohlpincherzeugung mit kondensierten Stickstoff-Molekularstrahlen / Current Distribution and Mass Pickup during a Hollow Dynamic Pinch Discharge in Condensed Molecular Beams of Nitrogen

The current distribution during a z-pinch discharge in a hollow cylindrical beam of nitrogen clusters is determined by magnetic probe measurements. After breakdown a current sheath arises within the ring-shaped cross section of the cluster beam. During the discharge the sheath is accelerated radially inward towards the axis. Simultaneously the radial collapse of a hollow luminosity pattern is observed by image converter photographs. The arrival of the current sheath at the axis coincides with the rapid development of a luminous core in the photographs. The radius-time curve of the sheath is calculated with the measured density of the electrodynamic forces neglecting pressure terms. Comparison of the observed and the calculated radius-time curves seems to indicate that most of the injected mass of the cluster beam is swept inward by the pinch discharge.