Generation and Propagation of Shock Waves in Submillimeter Capillaries

摘要

Shock wave generation and propagation have been investigated experimentally in the submillimeter range. In a first preliminary experiment, shock waves were generated via a fs-laser-generated plasma in free air. Not too close to the optical breakdown site, shock propagation could be well described by Sedov's model. More close to it, the experimental data are consistent with the plasma pressure. The main part of the experiments concentrated on shock wave propagation in a capillary. The experimental results of LPP-generated shock waves can be well explained by Sedov's model. However, when the shock waves are generated by means of a valve, the situation is different. In particular, in contrast to shock wave propagation in a macroscopic tube, in a submillimeter capillary, strong deviations from the classical shock theory have been found. This may be explained by boundary and friction effects and will be subject of a more detailed investigation in future.