Radiation-driven shock and debris propagation down a partitioned pipe

Abstract

-Two experiments have been performed to measure the effects of pulsed radiation loads on the front of small tubular structures, using as an energy source the X-ray fluence produced by a Z-pinch at the Sandia National Laboratories Z Facility. The project had two major goals: to establish the feasibility of using the Z machine to study the phenomenology associated with debris generation and propagation down tubular structures with partitions; and to use the resultant experimental data to validate numerical hydrocodes (shock physics codes) so that we have confidence in their use in analyzing these types of situations. Two tubular aluminum structures (5 and 10 cm long and 1 cm inside dkuneter) were prepared, with aluminum partitions located at the front, halfway down the pipe, and at the rear. Interferometry (VISARS) provided multiple velocity histories for all of the partitions. In both experiments, the first barrier, which was exposed directly to the x-ray fluence, was launched into the pipe at a velocity of -2 km/s, accelerating to give a mean velocity of-2.6 km/s. Loss of plate integrity is inferred from the dispersed launch of the second partition at -1 Ian/s. Wall shocks propagating at 4.5 kmk were inferred, although stmin gage measurements did not succeed. Post-test metallography showed evidence of melting and partial vaporization of the plates, and turbulent mixing with material from the walls. Calculations qualhatively agree with the observed results, but slightly overpredict debris velocity, possibly due to overestimates of total energy fluence. An application for this work is the study of techniques for line-of-sight shock and debris mitigation on high-power pulse-power facilities such as Z and its follow-on machines.

High Intensity X-Ray Coupling to Meteorite Targets

“…2 ) X-ray pulses generated from an exploding wire/hohlraum configuration at the Sandia Z-machine have been used to generate shock wave driven high pressures (multi megabar range) on various test samples and structures in order to determine the equation of state (EOS) and constitutive properties of materials at these high pressures 1 . Following this lead, we report on the utilization of the Sandia Z-machine to irradiate several meteorite specimens with soft Xrays (Plankian and line emission) in order to study the meteorite targets' response to high rates of dynamic loading provided by the ablation driven shock waves and the ensuing high pressure generation throughout the target sample.…”