Efficient ion acceleration by collective laser-driven electron dynamics with ultra-thin foil targets

TL;DR

This paper demonstrates efficient ion acceleration using ultra-thin DLC foils irradiated by high-contrast lasers, with simulations showing collective electron dynamics as the key mechanism for energy gain.

Contribution

It introduces a novel approach combining ultra-thin foil targets and laser parameters to enhance ion acceleration via collective electron motion.

Findings

Maximum proton energy of 13 MeV achieved

Carbon ions reach 71 MeV energy

Collective electron motion dominates ion acceleration mechanism

Abstract

Experiments on ion acceleration by irradiation of ultra-thin diamond-like carbon (DLC) foils, with thicknesses well below the skin depth, irradiated with laser pulses of ultra-high contrast and linear polarization, are presented. A maximum energy of 13MeV for protons and 71MeV for carbon ions is observed with a conversion efficiency of > 10%. Two-dimensional particle-in-cell (PIC) simulations reveal that the increase in ion energies can be attributed to a dominantly collective rather than thermal motion of the foil electrons, when the target becomes transparent for the incident laser pulse.