Heavy ion acceleration in the Breakout Afterburner regime

TL;DR

This study explores heavy ion acceleration using ultrathin gold foils and laser pulses, identifying efficient regimes and demonstrating high-flux, high-energy gold ion beams through simulations of different laser systems.

Contribution

It introduces two efficient heavy ion acceleration schemes in the Breakout Afterburner regime and compares their effectiveness with different laser pulse durations.

Findings

Gold ion beams with flux >10^11 ions/sr and energy >10 MeV/nucleon were generated.

Transition from Radiation Pressure Acceleration to Breakout Afterburner regime observed.

Both laser systems produced directional gold ion beams with high flux and energy.

Abstract

Theoretical study of heavy ion acceleration from an ultrathin (20 nm) gold foil irradiated by sub-picosecond lasers is presented. Using two dimensional particle-in-cell simulations we identified two highly efficient ion acceleration schemes. By varying the laser pulse duration we observed a transition from Radiation Pressure Acceleration to the Breakout Afterburner regime akin to light ions. The underlying physics and ion acceleration regimes are similar to that of light ions, however, nuances of the acceleration process make the acceleration of heavy ions more challenging. Two laser systems are studied in detail: the Texas Petawatt Laser and the Trident laser, the former having pulse duration 180 fs, intermediate between very short femtosecond pulses and picosecond pulses. Both laser systems generated directional gold ions beams (~10 degrees half-angle) with fluxes in excess of 1011 ion/sr and normalized energy >10 MeV/nucleon.