Effect of resistivity on dynamics of the wire arrays

Summary form only given, as follows. We report on the implosion dynamics of single nickel and copper wire arrays on the MAGPIE generator with a 1.4 MA, 240 ns current pulse. Plasma formed from individual wires has a core-corona structure. In the nickel arrays, a core size of 75 /spl mu/m is measured by X-ray radiography. The formation of precursor on axis takes place at about 150 ns. Initially the precursor plasma is stable but shows an m=1 instability later in time. The implosion of the array occurs later than that predicted by a 0-D model, indicating that a fraction of the current flows through the precursor plasma. Like aluminum and tungsten, the m=1 instability in the precursor plasma is not observed in the copper arrays, and the implosion time is in accordance with a 0-D model. This implies that the resistivity of the wires play an important role in the dynamics of the wire arrays. Detailed results are presented.