Laser-driven 1 GeV carbon ions from preheated diamond targets in the break-out afterburner regime

Experimental data are presented for laser-driven carbon C6+ ion-acceleration, verifying 2D-PIC studies for multi-species targets in the Break-Out Afterburner regime. With Trident's ultra-high contrast at relativistic intensities of 5 × 1020 W/cm2 and nm-scale diamond targets, acceleration of carbon ions has been optimized by using target laser-preheating for removal of surface proton contaminants. Using a high-resolution wide angle spectrometer, carbon C6+ ion energies exceeding 1 GeV or 83 MeV/amu have been measured, which is a 40% increase in maximum ion energy over uncleaned targets. These results are consistent with kinetic plasma modeling and analytic theory.