"Tandem puff-on-wire" experiments on ACE 4

Abstract

Summary form only given, as follows. Prior experiments showed enhanced soft (/spl sim/1 keV) and significant hard (6 keV) X-ray output for aluminum plasma jet implosions that included a central metal wire. In an effort to confirm those results and to establish the operative physical processes, we adapted the puff-on-wire geometry to the tandem puff load on the 4 MJ ACE 4 inductive energy storage (IES) machine. Most of our experiments used an 11 centimeter diameter neon gas puff surrounding central fine (25-75 micron diameter) wires of copper, molybdenum, silver and tungsten. In addition to standard soft radiation sensors (calorimeters, XRDs, PCDs, etc.), our diagnostics included a nine channel silicon PIN diode spectrometer covering the range from /spl sim/6 to over 300 keV. Peak current into the load exceeded 3 megamps. We do see increased soft and hard X-ray output when a central wire is in place. Time resolved data show that the soft and hard X-ray components begin at the same time but their evolutions vary with wire atomic number. The time scale of the hard radiation exceeds 100 ns. The hard X-ray yield increases with wire atomic number.