PULSED HOLOGRAPHY FOR HYPERVELOCITY IMPACT DIAGNOSTICS

The development of pulsed holography has two principal objectives. The first objective is to quantify the three dimensional characteristics of hypervelocity impact events, and the second is to provide a diagnos tic with the ability to capture high fidelity information for the vali dation of sophisticated three-dimensional hydrocodes. The holographic image-capturing subsystem uses a Q-switched, seeded, frequency-doubled Nd-YAG laser which produces 5 ns, 750 mJ, coherent pulses at 532 nm. Holographic images have been captured of the back-surface debris bubbl e from 4 km/s perforating impacts and crater ejecta from 2 km/s non-pe rforating impacts. A prototype holographic reconstruction and image an alysis subsystem has been assembled that provides the ability to measu re both the spatial distribution of particles and the morphology of in dividual particles produced in a hypervelocity impact event. The demon strated image resolution of this system is 20 mum; however, higher res olutions are possible with magnification optics.