Ion acceleration from aluminum foil coated with a gold nanolayer irradiated by ultrashort laser pulses

Abstract

Enhancement of proton energy has always been a key aspect addressed via laser-driven proton acceleration. As the target normal sheath acceleration protons are driven by the electric field produced at the target rear surface, the presence of a gold nanolayer on the surface of the target foil will enhance the energy of accelerated ion beams. In our study, we used a 30 fs laser pulse with a wavelength of 800 nm and a peak intensity of 3×1020 W/cm2. The targets were 2 μm thick aluminum foils coated with a 10–20 nm layer of gold (Au). It was observed that the dynamics of proton acceleration from the foil target is a function of the position of the nanolayer (front or rear surface). 2D particle-in-cell simulation was also performed in support of the observed experimental results.