Spatial-temporal characteristics analysis of laser-induced shockwave pressure by reverse optimization with multi-island genetic algorithm

Abstract

Laser-induced shock wave (LSW) represents a significant phenomenon arising from the interaction between laser radiation and matter. In this study, we establish a finite element and optimization model constrained by a physical framework. Utilizing multichannel photon Doppler velocimeter experimental data as the target for matching, we directly acquire the spatiotemporal pressure characteristics of LSW through the multi-island genetic algorithm. The optimized outcomes show deviations from experimental results within 10%. Research reveals that the spatial uniformity of pressure deteriorates with increasing power density, accompanied by a gradual reduction in the proportion of peak pressure. Temporally, aside from the pressure caused by plasma, there are some small pressure peaks. When the laser's full width half maximum reaching 100 or 200 ns, the pressure decays prematurely. The duration of pressure does not extend to two to three times the duration of the laser pulse.