Studies of the initial phases of exploding W and Al wire and wire-array plasma formation using X-ray backlighting

Abstract

Summary form only given. Exploding W and Al wires and wire arrays have been investigated using direct (point-projection) X-ray backlighting as the principal diagnostic method. A 4.5 kA amplitude, 350 ns quarter-period rise time sinusoidal current source which damps in about 5 ps is delivered to one or more fine W (7.5, 10 or 13.5 /spl mu/m) or Al (13.5 or 25 /spl mu/m) wires approximately 6 cm away from one or two Mo X-pinch X-ray backlighter sources. The X-pinches are placed in parallel between the output electrodes of the 450 kA, 100 ns XP pulser at Cornell University, each thereby producing a sub-nanosecond X-ray pulse. The source size is small enough to permit micron-scale spatial resolution images of the exploding wires on X-ray film. By varying the relative timing between pulsing the current source for the W or Al wire or wires and the XP pulser, images of the initial explosion phase of W and Al wires have been obtained at times ranging upwards from about 100 ns after the start of the 4.5 kA current source.