Nonlinear Surface Plasma Wave Induced Target Normal Sheath Acceleration Of Protons

The mode structure of a large amplitude surface plasma wave (SPW) over a vacuum-plasma interface, including relativistic and ponderomotive nonlinearities, is deduced. It is shown that the SPW excited by a p-polarized laser on a rippled thin foil target can have larger amplitude than the transmitted laser amplitude and cause stronger target normal sheath acceleration of protons as reported in a recent experiment. Substantial enhancement in proton number also occurs due to the larger surface area covered by the SPW. (C) 2015 AIP Publishing LLC.