High quality ion acceleration from a double-layer target dominated by the radiation pressure of a transversely Gaussian laser pulse

The ion acceleration from a double-layer target irradiated by a transversely Gaussian laser pulse is investigated by theoretical analysis and particle-in-cell simulations. The main idea of the double-layer target is to match the transverse areal mass density of the target with the laser intensity profile by single ion specie with two densities or by two ion species. Two-dimensional particle-in-cell simulations show that the target deformation and the transverse instability are efficiently suppressed in the double-layer scheme, ions within the laser spot are uniformly accelerated and are well collimated in the forward direction, GeV/u monoenergetic ion beams with very low divergency are observed. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3503604]