Emission of MeV multiple-charged ions from metallic foils irradiated with an ultrashort laser pulse

From full kinetic particle-in-cell simulation including elastic collisions and collisional and field ionization, we find that the emission of MeV multiple-charged ions from a non-low-Z matter foil irradiated by a short laser pulse sensitively depends on the ion charge distribution. In spite of strong elastic collisions, the anisotropy of the hot electron velocity distribution enhances the ion energy and improves the emittance. With up to 10% conversion of the laser energy, Al⁺⁶-Al⁺⁷ ions over MeV energy are produced from 0.125{μ}m foil with an obliquely incident (45^∘{}) p-polarized laser pulse of 1 ps duration in the range of intensity 10^16-17W/cm².