2D axisymmetric numerical simulation of lens-focused laser-generated xenon plasma

Laser-generated plasma has attracted significant attention as a high-brightness broadband light source for applications such as semiconductor metrology and spectroscopic analysis. However, its performance is often constrained by spatial asymmetry and thermal inhomogeneity. This study presents a systematic numerical investigation of xenon laser-generated plasma dynamics using a time-dependent two-dimensional axisymmetric model. The model couples Reynolds-averaged Navier–Stokes equations with laser energy deposition, radiation transport, and gas dynamics under the assumption of local thermodynamic equilibrium. Thermophysical properties—including absorption coefficients (inverse bremsstrahlung and bound-bound), density, specific heat, enthalpy, viscosity, and thermal conductivity—were computed over an extended range of temperatures (300–30 000 K) and pressures (0.1–10 MPa) to ensure accuracy. Validation against experimental data in the 70–250 W range showed agreement within 5% in plasma size and 15% in peak temperature. Simulations under elevated conditions (0.5–15 kW; 0.1–10 MPa) reveal key insights: shorter wavelengths (e.g., 0.405 μm) yield compact plasmas (axial length 1.8 mm, radial diameter 0.6 mm at 1 MPa), while longer wavelengths lead to expanded morphologies. Increasing laser power induces upstream displacement of the plasma centroid—from 2 mm at 0.5 kW to 11.5 mm at 10 kW (1 MPa, 1.08 μm)—and elevates peak temperatures up to 34 000 K at 7.5 kW. Higher operating pressures enhance plasma energy density but only moderately reduce spatial extent. These findings provide critical guidance for the parameter-specific design and optimization of high-performance Laser-generated plasma light sources.