Quantitative imaging approaches dedicated to shock-physics experiments

Structured Light Systems (SLS) give access, without contact, to a rich measurement of a cloud of points belonging to a same object surface. SLS received much interest in the past years and became a standard technique. The aim of this talk is to present the design of such a means, working in the visible spectrum, dedicated to shock physics (implying velocities up to several km/s) and to provide an example of measurements with a 3D reconstruction. A dedicated development is necessary (laser lighting, speckle smoothing, ambient light canceling, depth of field improvement), since commonly developed SLS don’t suit this field of study, mainly for three reasons: phenomena of interest (usually lasting a few microseconds) require extremely short exposure durations (few nanoseconds to few hundreds of picoseconds); the field of view ranges from millimeter for samples shocked by high power lasers to decimeter for high-explosive setups ; and finally, experimentations have single-shot acquisitions. The main domains of study are fragmentations, surface deformations and associated damages, like micro-spalling or ejected particle clouds.