Radiographic and spectroscopic studies of X-pinch plasma implosion dynamics and x-ray burst emission characteristics

Abstract

Experimental results are presented from studies of the dynamics of X-pinch plasmas, formed using two fine wires that cross and touch at a single point (in the form of an X) as the load of a high current pulser. High-resolution (sub-ns in time and 2-3 μm in space) x-ray radiographs of X pinches driven by current pulses that rise to 200-250 kA peak current in 40 ns show that ≤300 μm long Z pinches form in the region of the original wire cross-point a few ns prior to the first sub-ns intense x-ray bursts that are characteristic of an X pinch. The Z pinches implode to ≤10 μm diam and then appear to develop gaps in the radiographic images in one or two places, coincident in time with the x-ray burst(s). The emission spectra of the intense x-ray bursts from different wire materials indicate electron temperatures of 500-1300 eV and densities in excess of 10 22/cm 3. © 2001 American Institute of Physics.