SHIVA Electromagnetic Implosion X-Ray Source

The generation of pulsed high-energy density plasmas by electromagnetic implosion of cylindrical foils (i.e., imploding liners or hollow Z-pinches) has been investigated experimentally and theoretically at the Air Force Weapons Laboratory. The experimental studies involve discharging a 1.3 microsecond, 1.1 megajoule capacitor bank through 7 cm radius, 2 cm tall, 3 to 30 mg cylindrical foil liners. Typical discharge parameters are 7 to 12 MA peak current and 1-1.5 microsecond current rise time. Current and voltage waveforms indicate strong coupling of the load to the capacitor bank, and analysis of the waveforms indicates good implosion of the current sheath. Optical and magnetic probe measurements are consistent with 1 to 2 cm thickness of the imploding plasma shell and with final implosion velocities. Comparison of electrical, magnetic, and radiation data with one dimensional magnetohydrodynamic and two dimensional magnetohydrodynamic calculations is presented. The prospects for improving the performance with the present energy source and scaling to larger energy sources are briefly discussed.