Stable laser-produced quasimonoenergetic proton beams from interactive laser and target shaping

Liu, J. L. and Chen, M. and Sheng, Z. M. and Liu, C. S. and Mori, W. B. and Zhang, J. (2013) Stable laser-produced quasimonoenergetic proton beams from interactive laser and target shaping. Physical Review Special Topics: Accelerators and Beams, 16 (12). 121301. ISSN 1098-4402

PDF (Liu-etal-PRST2013-stable-laser-produced-proton-beams)
Accepted Author Manuscript

Download (1MB)| Preview


    In radiation pressure dominated laser ion acceleration schemes, transverse target deformation and Rayleigh-Taylor (RT)-like instability always develop quickly, break the acceleration structure, limit the final accelerated ion energy, and lower the beam quality. To overcome these issues, we propose a target design named dual parabola targets consisting of a lateral thick part and a middle thin part, each with a parabolic front surface of different focus positions. By using such a target, through interactive laser and target shaping processes, the central part of the thin target will detach from the whole target and a microtarget is formed. This enables the stable acceleration of the central part of the target to high energy with high quality since usual target deformation and RT-like instabilities with planar targets are suppressed. Furthermore, this target design reduces the laser intensity required to optimize radiation pressure acceleration by more than 1 order of magnitude compared to normal flat targets with similar thickness and density. Two-dimensional particle-in-cell simulations indicate that a quasimonoenergetic proton beam with peak energy over 200 MeV and energy spread around 2% can be generated when such a solid target (with density 400nc and target thickness 0.5λ0) is irradiated by a 100 fs long circularly polarized laser pulse at focused intensity IL∼9.2×1021 W/cm2.