Characteristics of Al:Mg alloy wire-array z-pinches on the Z generator

The characteristics of 95% Al:5% Mg alloy wire-array z-pinches formed by the Z generator and their associated x-emission are discussed. The arrays consisted of 180 to 266 wires, with each wire being 20-mm long and mounted at radii of 15, 20, or 25 mm. The implosion time of the loads explored was maintained at ∼106 ns by keeping M*R*R constant. M is the array mass that decreased from 7.1 to 4.2 to 2.6 mg as the radius R was increased. Current at the load was measured by B-dot monitors, and piezo-electric pressure gauges. These monitors showed that peak currents of ∼19 MA were generated in agreement with Screamer power-flow simulations. The temporally-resolved radiation field was measured by spatially-integrating resistive bolometers, filtered XRDs, and PCDs in 12 discrete channels that spanned the energy range 5 eV to 7 keV. Preliminary analysis indicates that the total radiated energy generated is of the order of 1 MJ and produces a total x-ray power on the order of 65 TW. The K-shell energy yield shows a strong dependence on mass increasing from ∼90 to ∼200 kJ as the mass decreases from 7.1 to 2.6 mg. Opacity effects are manifested by the share of Mg radiation greatly exceeding its 5% number ratio. Over this range, the associated FWHM of the K-shell emission decreases from 20 to 13 ns and the peak K-shell power increases from 4 to 12 TW, respectively, The x-ray images suggest the presence of a Rayleigh-Taylor instability. Two-dimensional radiation-magnetohydrodynamic simulations in the R-Z plane give insight into the mass distribution arising from this instability