Kinetic modeling of plume-shockwave interactions during laser-produced plasma expansion in background gas

Abstract

We explore the effects of shockwave formation on the expansion of laser-produced plasmas (LPP) using the direct simulation Monte Carlo (DSMC) method. We have shown that the huge number of collisions within the initial plume drives the forward-directed expansion, and the background gas slows down the plume as it approaches the target. The shock front formation within the plume and background gas agrees with literature on experimental LPP expansion. Furthermore, we discuss the increased density and distorted shape of the plume as it collides with the argon shock front that is reflected from the substrate. The plume deceleration and distortion due to shockwave collision have potential applications in laser breakdown spectroscopy and nanoparticle fabrication.