Evidence for large heat fluxes from the mass ablation rate of laser-irradiated spherical targets

The mass ablation rate from spherical targets irradiated at wavelengths of 1.05 and 0.53 μm has been measured with particle and with x-ray diagnostics. The specific mass ablation rate is found to be proportional to I0.7a with little wavelength dependence for a given value of Ia, the absorbed irradiance. Comparisons with simulations shows that heat fluxes up to and in excess of 10% of the free streaming value are occurring. Values of the ablation pressure are derived.