Structure and observable characteristics of laser driven ablation

Numerical hydrodynamic-heat flow simulations of spherical ablation have been done with sufficient spatial resolution to show the details of the ablation front structure. These simulations show a continuous qualitative change in the velocity spectrum of expanding ions with increasing laser pulse length, ranging from approximately isothermal behavior from short pulse to ablative behavior from longer pulses. The ablative behavior is characterized by an energetic peak in the ion spectrum, a characteristic of ablation that is experimentally observable. The longer pulse cases are found to be in good agreement with the stationary flow model of ablation.