DYNAMICS OF A HIGH-POWER ALUMINUM-WIRE ARRAY Z-PINCH IMPLOSION

Annular Al-wire Z-pinch implosions on the Saturn accelerator [D.D. Blo omquist et al., Proceedings, 6th Pulsed Power Conference (Institute of Electrical and Electronics Engineers, New York, 1987), p. 310] that h ave high azimuthal symmetry exhibit both a strong first and weaker sec ond x-ray burst that correlate with strong and weaker radial compressi ons, respectively. Measurements suggest that the observed magnetic Ray leigh-Taylor (RT) instability prior to the first compression seeds an m=0 instability observed later. Analyses of axially averaged spectral data imply that, during the first compression, the plasma is composed of a hot core surrounded by a cooler plasma halo. Two-dimensional (2-D ) radiation magnetohydrodynamic computer simulations show that a RT in stability grows to the classic bubble and spike structure during the c ourse of the implosion. The main radiation pulse begins when the bubbl e reaches the axis and ends when the spike finishes stagnating on axis and the first compression ends. These simulations agree qualitatively with the measured characteristics of the first x-ray pulse and the ov erall energetics, and they provide a 2-D view into the plasma hydrodyn amics of the implosion.