Monte Carlo modeling of emission enhancement in double-pulse Laser Induced Breakdown Spectroscopy

Abstract

Double-pulse laser-induced breakdown spectroscopy (DP-LIBS) enhances emission intensity, but the mechanisms governing plume interaction remain unclear. In this work, the expansion of a copper laser-produced plasma in argon was investigated using the direct simulation Monte Carlo method implemented in SPARTA. Single-pulse and double-pulse configurations with interpulse delays of 1 μs and 3 μs were analyzed to examine plume dynamics under varying collisional conditions. Results show that a short delay (1 μs) leads to strong plume confinement and prolonged lifetime due to interaction with a dense, highly collisional plasma, resulting in increased number density but reduced peak temperature. In contrast, a longer delay (3 μs) produces higher peak temperatures and a more pronounced plume front due to reduced collisional damping in a rarefied environment. Plume-plume interaction enhances density and extends plume propagation relative to the single-pulse case.