A simple model for cavity-enhanced laser-driven ion acceleration from thin foil targets

TL;DR

This paper proposes a simple model for enhancing laser-driven ion acceleration from thin foils by enclosing the target in a reflecting cavity, which redirects reflected laser pulses to improve acceleration efficiency.

Contribution

It introduces a semi-analytic formula to describe cavity reflection effects in laser-driven ion acceleration, extending the light-sail model to include cavity-enhanced dynamics.

Findings

Cavity reflections can significantly boost ion acceleration efficiency.

The model applies to ultra-intense laser pulses of different durations.

Enhanced acceleration is demonstrated through two example scenarios.

Abstract

A scenario for the enhanced laser-driven ion acceleration from a thin solid target at high laser intensity is considered, where the target is enclosed in a reflecting cavity. The laser pulse reflected from the target is redirected towards the target by reflection at the inner cavity wall. This scenario is discussed in the context of sub-wavelength foil acceleration in the radiation pressure regime, when plasma dynamics is known to be reasonably well described by the light-sail model. A semi-analytic formula is presented that describes the effect of cavity reflections in one-dimensional geometry. The effect of cavity reflections on sub-wavelength foil acceleration is then evaluated for two concrete examples of ultra-intense laser pulses of picosecond and femtosecond duration.