Stability of Ion Acceleration in a Plasma Dominated by the Radiation Pressure of an Electromagnetic Pulse

The electric fields produced by the interaction of ultra-short and ultra-intense laser pulses with a thin target make it possible to obtain multiMeV , high density, highly collimated proton and ion beams with duration in the sub-picosecond range. Critical features are the efficiency of the ion acceleration process and the energy spectrum of the produced ion beam. At high laser intensities the radiation pressure of the laser pulse foil plays a major role in the acceleration process. We discuss the stability of this regime against the onset of Rayleigh-Taylor deformations of the plasma foil. Introduction The effective ion acceleration up to a few tens ofMeV during the interaction of an ultra short and ultra intense laser pulse with matter is possibly one of most important results of the interaction of multi-terawatt and petawatt power laser pulses with plasmas. Compared to conventional accelerators these proton beams have a very high brilliance and are very directional, with a divergence of a few degrees at the highest energies and an apparent source size of less than 5 − 10 μm. The number of particles in the beams can approach 10 in bursts of ps duration, three orders of magnitude shorter than conventional accelerator bunches, and with good conversion efficiency of the laser energy. These laser-produced ion beams have important applications ranging from the fast ignition of thermonuclear