Measuring sound velocities along release adiabats with Manganin stress gauges

We propose a new technique to measure the state of shock‐loaded specimens along their release adiabats. The technique is based on symmetric impacts of equal thickness flyer and target disks. A Manganin stress gauge is embedded at the back of the target and backed by a thick Plexiglas disk. The stresses at the specimen–Plexiglas interface are relieved in a stepwise manner which is typical for this type of experiment. From the time duration between consecutive release waves one can determine the sound speed in the released specimen. Drastic changes in sound speed, as in melting, can be detected by these time durations adding more information on the state of the specimen as it unloads from very high shock stresses.