Demonstration of a telecentric lens relay system for PDV in plate-impact experiments.

Photon Doppler velocimetry (PDV) has become a standard diagnostic in impact and shock experiments, due to its relative flexibility and ease in alignment compared to other optical diagnostics. The conventional approach to fielding PDV in plate-impact experiments is to place probes directly down-range from the projectile and target. In experiments such as these, probes are almost certainly destroyed, resulting in significant replacement cost particularly when multiple probes are used. To overcome these shortcomings, a free-space optical relay system has been developed to focus multiple channels of PDV from outside an experimental tank onto a target of reduced size than the probe array. This system has been successfully tested on plate-impact experiments measuring a Hugoniot state of polycrystal tin, and the peak elastic stress and spall strength in 6082 aluminium alloy, in both cases adding information about the shock tilt to the experimental data generated. [ABSTRACT FROM AUTHOR]