Numerical simulations of generation of high-energy ion beams driven by a petawatt femtosecond laser

Abstract

Abstract. This contribution presents results of a Particle-in-Cell simulation of ion beam acceleration via the interaction of a petawatt 25 fs laser pulse of high intensity (up to ~10 21 W/cm 2 ) with thin hydrocarbon (CH) and erbium hydride (ErH 3 ) targets of equal areal mass density (of 0.6 g/m 2 ). A special attention is paid to the effect that the laser pulse polarization and the material composition of the target have on the maximum ion energies and the number of high energy (>10 MeV) protons. It is shown that both the mean and the maximum ion energies are higher for the linear polarization than for the circular one. A comparison of the maximum proton energies and the total number of protons generated from the CH and ErH 3 targets using a linearly polarized beam is presented. For the ErH 3 targets the maximum proton energies are higher and they reach 50 MeV for the laser pulse intensity of 10 21 W/cm 2 . The number of protons with energies higher than 10 MeV is an order of magnitude higher for the ErH 3 targets than that for the CH targets.

Numerical studies of petawatt laser-driven proton generation from two-species targets using a two-dimensional particle-in-cell code

“…Also the mean velocities of proton are higher for erbium hydride targets (especially for linear polarization). The observed difference matches up to the previous results obtained for lower intensities and one dimensional simulations [22,24,26] and could be explained by the difference in the strength of interaction between heavier ions (C, Er) and the electric field induced in plasma by the laser pulse. This interaction depends on the q/m parameter (q is the ion charge, m is the ion mass) which for erbium ions is much smaller than for C ions.…”

“…The parameters of laser-accelerated ion beams depend also on the target composition. However, the effect of this composition on the process of ion acceleration was studied in much lesser degree [22][23][24][25][26], in spite of the fact that the structure of the target can have a fairly big influence on the efficiency of this process and on properties of generated ion beams and proton beams in particular.…”