Rayleigh-Taylor instability in ion beam driven ablation fronts

A physical model for the linear stage of Rayleigh-Taylor instability in ablation fronts is presented. The model allows for direct physical interpretation and for retrieving the well known results for the instability growth rate in ablation fronts driven by thermal diffusion. The model is applied to ablation fronts directly driven by intense ion beams and the instability growth rate is found. We show that ablation by itself still provides a mechanism for growth rate reduction but the cutoff wave number above which the front becomes stable, does no exist in ion beam driven ablation fronts. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3212592]