Foil implosion studies with a plasma flow switch

Summary Form only given, as follows. A plasma flow switch has been developed for the 1.5-MJ Pegasus capacitor bank to utilize the bank energy (quarter-cycle approximately 4 mu s) efficiently to drive a foil implosion (foil initiation and run-in approximately 1-2 mu s). The object of this activity is to generate an intense burst of soft X-rays when the foil stagnates and thermalizes on axis. A typical free-standing aluminum annular foil is 2500-AA thick, 10-cm in diameter, and 2-cm high. The peak current of the Pegasus bank is approximately 10 MA. When used in direct-drive, foil-implosion experiments, the foil collapses to the axis when the current rises to only approximately 3 MA. The kinetic energy of the imploding foil for the direct-drive configuration cannot exceed approximately 25% of the bank energy (lossless calculation). The plasma flow switch has been designed to have a conduction time of approximately 4 mu s and a commutation time of approximately 0.2 mu s. This permits flow-implosion experiments to be performed at peak current.<>