Surface Plasmon-Driven Electron and Proton Acceleration without Grating Coupling

TL;DR

This paper demonstrates through simulations that surface plasmon-driven electron and proton acceleration can be achieved on flat foils at grazing incidence without the need for grating coupling, simplifying experimental setups.

Contribution

It introduces a novel method for surface plasmon excitation and particle acceleration using flat targets and grazing incidence, eliminating the need for surface gratings.

Findings

Efficient electron acceleration occurs on flat foils at grazing incidence.

Proton beams with narrow spectra exceeding 100 MeV can be generated.

The method works with currently available short pulse lasers.

Abstract

Surface plasmon (SP) excitation in intense laser interaction with solid target can be exploited for enhancing secondary emissions, in particular efficient acceleration of high charge electron bunches. Previous studies have mostly used grating coupling to allow SP excitation, which requires stringent laser contrast conditions to preserve the structural integrity of the target. Here we show via simulations that efficient SP electron acceleration for currently available short pulse lasers can occur in a flat foil irradiated at parallel or grazing incidence ($\sim 5^\circ$ with the target surface) without a surface modulation. In turn, the accelerated electrons can be effective for generating proton beams with narrow spectra peaked at $>$100 MeV energies for currently available laser drivers.