Comprehensive investigation of Rayleigh-Taylor instability in laser-induced copper plasma: spectroscopic diagnostics and morphological analysis
Abstract
The conducted experiments and theoretical analysis revealed that picosecond-durationNd:YAG laser irradiation induces highly complex thermal and hydrodynamic processes on thesurface of copper foil. Spectroscopic measurements showed that the determined plasma parameters(Тe ≈ 8825 K and ne = (0.23–14.8)×1018 см−3) are closely related to pressure gradientsand variations in surface tension. Scanning electron microscopy images showed direct traces ofstability in the craters: additional instabilities resulting from the ablative Rayleigh-Taylor process,Marangoni convection, and density reduction had a significant impact on the crater shapeand size. This clarified Scanning electron microscopy images of the craters demonstrated directtraces of instabilities: the ablative Rayleigh-Taylor process, Marangoni convection, andadditional instabilities caused by rarefaction significantly influenced the crater shape and volume.This clarified the key mechanisms of material redistribution under laser irradiation. Thus,the research findings provided a deeper understanding of crater formation through accurateplasma characterization and theoretical modeling of instabilities. The conclusions obtainedserve as a solid scientific basis for high-precision surface modification and the creation ofnanostructures using laser technologies.