Observations of the plasma in a two-wire Z-pinch

Summary form only given, as follows. We report on experiments performed on two parallel wire Z-pinch driven by a current up to 150 kA, with a rise time (10%-90%) of 65 ns. Aluminium and tungsten wires of diameters 5 to 18 m and separated by distances 300 m to 3 mm were used. The plasma dynamics was studied with schlieren photography and a two frame moire deflectometry with a 7 ns pulsed ruby laser. In addition, time integrated pinhole camera, streak camera, crystal spectrometer and filtered PIN diodes were used to monitor the X-ray emission. Preliminary observations show that the expansion of the plasma ablated from the wires is at a higher speed in the region between the wires than outside the two wires. The ablated plasma from the wires also develop non-uniformities typical of the m=0 instability. The non-uniformity of the plasma in the region between the wires appears to be spatially random and uncorrelated, whereas the structure in the region outside the wires is spatially correlated along each wire.