Stochastic Shock Observations from Plate Impact of Porous Tantalum*

Comparative multi- and single-point velocimetry measurements were made and used to explore spatial variability in the shock response of porous tantalum films prepared by thermal-spray deposition. The material pore structure was elucidated using x-ray tomography at the Advanced Photon Source. Multi-point velocimetry included frequency-based Photonic Doppler Velocimetry (PDV) and quadrature-based Photonic Displacement Interferometry (PDI), each with two different optical configurations allowing up to 13 measurements per sample, with up to three samples per shot. In addition, complementary single-point VISAR data were acquired. Variations in loading history are compared between identically-impacted sapphire and porous tantalum for flyer-plate velocities up to \textasciitilde 300 m/s.