Using the line-VISAR to study multi-dimensional and mesoscale impact phenomena

The line-VISAR is an optical interferometry system that allows velocities to be measured in a spatially and temporally resolved manner. The ability to measure velocity not only as a function of time but also as a function of position represents a significant advance over other diagnostics and opens up several new avenues of research. Over the last few years, the line-VISAR has been used to study a variety of phenomena related to material behavior at the mesoscale such as crushing of granular sugar, nonuniform failure of materials such as the statistics of spall strength, and multi-dimensional configurations such as flyer launch, embedded defects, and material interfaces. Here, we review the studies reported to date that utilized the line-VISAR in the investigation as well as presenting new results on nonuniformity of the phase transformation in iron and hypervelocity flyer launch with the Z machine. As part of the review, we will highlight examples of multi-dimensional applications resulting from impacts over the velocity range of 0.20 to 13 km/s. These examples demonstrate that the line-VISAR can be a valuable addition to the suite of diagnostics for impact and hypervelocity phenomena. (C) 2008 Elsevier Ltd. All rights reserved.