Femtosecond laser driven ion acceleration

Esirkepov, T. Z.

A relativistically strong femtosecond laser pulse can produce in plasmas a long-living collective electric field with magnitude greater than TV/m. An efficient generation of fast ion beams with unique properties has been recorded in experiments on the interaction of terawatt-petawatt laser pulses with solid targets. The scaling laws of the ion acceleration driven by a terawatt-petawatt laser pulse from a double layer target are obtained with multi-parametric Particle-in-Cell simulations. For targets with a wide range of thickness and density, at given laser intensity the highest ion energy gain occurs at certain areal density of the target, which is proportional to the square root of intensity. For thin targets and optimal laser pulse duration, the ion maximum energy scales as the square root of the laser pulse power. When the radiation pressure of the laser field becomes dominant, the ion maximum energy becomes proportional to the laser pulse energy.