Suppressing longitudinal double-layer oscillations by using elliptically polarized laser pulses in the hole-boring radiation pressure acceleration regime

TL;DR

This paper demonstrates that elliptically polarized laser pulses can suppress double-layer oscillations in the hole-boring radiation pressure acceleration regime, leading to higher quality mono-energetic ion beams, confirmed by Particle-in-Cell simulations.

Contribution

The study introduces a novel method using elliptically polarized lasers to suppress oscillations and improve ion beam quality in laser-driven acceleration.

Findings

Suppression of double-layer oscillations with elliptically polarized lasers.

Generation of well-collimated, mono-energetic ion beams.

Enhanced energy spectrum of ion beams compared to circular polarization.

Abstract

It is shown that well collimated mono-energetic ion beams with a large particle number can be generated in the hole-boring radiation pressure acceleration regime by using an elliptically polarized laser pulse with appropriate theoretically determined laser polarization ratio. Due to the $\bm{J}\times\bm{B}$ effect, the double-layer charge separation region is imbued with hot electrons that prevent ion pileup, thus suppressing the double-layer oscillations. The proposed mechanism is well confirmed by Particle-in-Cell simulations, and after suppressing the longitudinal double-layer oscillations, the ion beams driven by the elliptically polarized lasers own much better energy spectrum than those by circularly polarized lasers.