Ultraintense proton beams from laser-induced skin-layer ponderomotive acceleration

The results of studies of high-intensity proton beam generation from thin (1-3 μm) solid targets irradiated by 0.35 ps laser pulse of energy up to 15 J and intensity up to 2× 1019 W/ cm2 are reported. It is shown that the proton beams of terawatt power and intensity around 1018 W/ cm2 at the source can be produced when the laser-target interaction conditions approach the skin-layer ponderomotive acceleration requirements. The proton beam parameters remarkably depend on the target structure and can be significantly increased with the use of a double-layer Au/PS target (plastic covered by 0.1-0.2 μm Au front layer).