Dynamic interface instabilities including the Kelvin-Helmoltz (shear), Rayleigh-Taylor (acceleration), and Richtmyer-Meshkov (shock) instabilities play important roles in such varied conditions as explosive welding, inertial confinement fusion, and supernovae. Besides their importance to those applications, the emergence and development of these instabilities are influenced by the properties of the materials involved. Thus, they can be used as a way to study material behavior for unrelated applications. For example, Rayleigh-Taylor instability growth driven by lasers or explosive products has been used to study the high-pressure high-strain rate response of metals, and Richtmyer-Meshkov instabilities (RMI) growth has been used to study the strength of metals at high strain rates and low pressures. Recently, tamped RMI experiments have extended the approach to elevated pressures. If the behavior of the jetting material is known, the tamped RMI experiment can be used to study the behavior of the tamping material. Effectively, it becomes a dynamic indentation/penetration experiment. This is especially useful when the tamping material is not a ductile metal suited to instability growth. Here, we characterize the behavior of copper in untamped and tamped RMI configurations. We then use the tamped RMI configuration to study the strength behavior of other materials that are used as tampers. Because these materials are opaque to optical light, we utilize synchrotron X-ray radiation from the Advanced Photon Source and perform the experiments at the Dynamic Compression Sector. Results are compared to other strength measurements made at high pressures and strain rates.
Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.