Schlieren diagnostics of the plasma focus using a mode-locked dye laser

Abstract

By means of schlieren techniques the discharge characteristics of a 1 kJ plasma focus device were investigated. Different inner electrodes were used with diameters ranging from 4 mm to 10 mm and the working gases were hydrogen and neon. A spatial resolution in the μm region and a temporal resolution in the ps region could be achieved using a mode-locked dye laser as schlieren light source. During the run-down and collapse phase of the discharge the spatially and temporally resolved electron density was determined from the schlieren pictures by means of numerical simultations of the beam deflection by the plasma. During the focus phase the temporal development of the plasma could be observed.