# Enhancement of laser-driven ion acceleration in non-periodic nanostructured targets

## TL;DR

This study uses particle-in-cell simulations to show that non-periodic nanostructured targets, like nanocones and nanoholes, significantly enhance laser-driven proton acceleration by increasing hot-electron generation and interaction efficiency.

## Contribution

It demonstrates that non-periodic nanostructured targets improve TNSA performance without requiring periodic arrangements, relaxing manufacturing constraints.

## Key findings

- Proton cutoff energy increases up to twofold with nanostructures.
- Nanohole perforated foils yield the highest enhancement.
- Performance is robust across various foil thicknesses and hole sizes.

## Abstract

Using particle-in-cell simulations, we demonstrate an improvement of the target normal sheath acceleration (TNSA) of protons in non-periodically nanostructured targets with micron-scale thickness. Compared to standard flat foils, an increase in the proton cutoff energy by up to a factor of two is observed in foils coated with nanocones or perforated with nanoholes. The latter nano-perforated foils yield the highest enhancement, which we show to be robust over a broad range of foil thicknesses and hole diameters. The improvement of TNSA performance results from more efficient hot-electron generation, caused by a more complex laser-electron interaction geometry and increased effective interaction area and duration. We show that TNSA is optimized for a nanohole distribution of relatively low areal density and that is not required to be periodic, thus relaxing the manufacturing constraints.