Key parameters for surface plasma wave excitation in the ultra-high intensity regime

TL;DR

This paper investigates the optimal conditions for exciting surface plasma waves using ultra-high intensity lasers, revealing key parameters that enhance electron acceleration and informing future high-power laser experiments.

Contribution

The study identifies the best conditions for surface plasma wave excitation at ultra-high intensities through Particle-in-Cell simulations, linking laser incidence angle and plasma parameters.

Findings

Optimal surface plasma wave excitation angle correlates with laser incidence angle.

Adjusting plasma density and surface shape can extend excitation limits.

Results facilitate future experiments with multi-petawatt laser systems.

Abstract

Ultra-short high-power lasers can deliver extreme light intensities ($\ge 10^{20}$ W/cm$^2$ and $\leq 30 f$s) and drive large amplitude Surface Plasma Wave (SPW) at over-dense plasma surface. The resulting current of energetic electron has great interest for applications, potentially scaling with the laser amplitude, provided the laser-plasma transfer to the accelerated particles mediated by SPW is still efficient at ultra-high intensity. By mean of Particle-in-Cell simulations, we identify the best condition for SPW excitation and show a strong correlation between the optimum Surface Plasma Wave excitation angle and the laser's angle of incidence that optimize the electron acceleration along the plasma surface. We also discuss how plasma density and plasma surface shape can be adjusted in order to push to higher laser intensity the limit of Surface Plasma Wave excitation. Our results open the way to new experiments on forthcoming multi-petawatt laser systems.