Laser induced damage simulations of silica surface under 1.053 μm irradiation

Simulations of laser-silica interaction at 1.053 and 0.351 mum is a key issue in predicting and quantifying laser damage in large laser systems such as LIL, LMJ or NIF. Laser induced damage will occur in many locations. Pure intrinsic (defect free materials) laser damage of "real world" fused silica does not exist in the nanosecond pulse length range. That is why many attempts to model laser damage using intrinsic properties failed. It does not mean that intrinsic phenomena (avalanche ionization...) do not play a role in laser damage. We have introduced extrinsic features of fused silica in our calculations. Surface defects are modeled in terms of electronic density gradients. We use Monte Carlo simulation to extract avalanche ionization coefficients and collision frequencies. We use fluid equations to determine electric conductivity and compute the electric field distribution with Helmholtz equation in our 1D hydrodynamic DELPOR code where Joule heating, thermal conduction and electron diffusion are taken into account.