Laser-wavelength dependence of mass-ablation rate and heat-flux inhibition in laser-produced plasmas

Abstract

Thin-foil experiments at 1.06, 0.53, and 0.26 \ensuremath{\mu}m have been realized in order to measure mass-ablation rate $\stackrel{\ifmmode \dot{}\else \.{}\fi{}}{m}$ as a function of absorbed laser flux ${\ensuremath{\varphi}}_{a}$ and laser wavelength $\ensuremath{\lambda}$. The results can be put in the form $\stackrel{\ifmmode \dot{}\else \.{}\fi{}}{m}(\mathrm{kg}/\mathrm{s}{\mathrm{cm}}^{2})\ensuremath{\approx}110{[{\ensuremath{\varphi}}_{a}\frac{(\mathrm{W}/{\mathrm{cm}}^{2})}{{10}^{14}}]}^{\frac{1}{3}}{\ensuremath{\lambda}}_{\ensuremath{\mu}\mathrm{m}}^{\ensuremath{-}\frac{4}{3}}$. Hydrodynamical simulations of these experiments show that heat-flux inhibition occurs at each wavelength, but the mechanisms are very different.