Multiwire X Pinches on the COBRA Pulsed Power Generator

The rebuilt COBRA pulsed power generator, which has a variable current pulse waveform and amplitude (90–150 ns rise time, 0.6 – 1 MA) has extended the range of current pulse parameters that can be used to study X pinches. X pinches with 2 to 12 wires with diameters from 25 to 75 μm of several different wire materials (from Al to W) have been studied. The influence of different current shapes on X pinch plasma formation and pinch implosion dynamics has been studied using a set of diagnostics with spatial and/or temporal resolution. Multiwire X pinches were placed in the diode center and/or two four wire X pinches were places in one of four parallel return current circuits of the diode. Radiographic images of different test objects, wires in the array and the X pinches, themselves, were obtained with μm scale spatial resolution.