Guided post-acceleration of laser-driven ions by a miniature modular structure

TLDR

All‑optical particle acceleration attracts global research, yet laser‑driven ion beams suffer from limited peak energy, narrow bandwidth, and high divergence despite excellent emittance. We propose a miniature linear accelerating module that uses laser‑excited electromagnetic pulses along a helical path to simultaneously overcome these limitations. A university‑scale proof‑of‑principle experiment demonstrates post‑acceleration of laser‑driven protons from a flat foil at 0.5 GeV m⁻¹, surpassing conventional accelerators, while providing dynamic beam collimation and energy selection. These results enable the development of extremely compact, cost‑effective ion accelerators for both established and innovative applications.

Abstract

Abstract All-optical approaches to particle acceleration are currently attracting a significant research effort internationally. Although characterized by exceptional transverse and longitudinal emittance, laser-driven ion beams currently have limitations in terms of peak ion energy, bandwidth of the energy spectrum and beam divergence. Here we introduce the concept of a versatile, miniature linear accelerating module, which, by employing laser-excited electromagnetic pulses directed along a helical path surrounding the laser-accelerated ion beams, addresses these shortcomings simultaneously. In a proof-of-principle experiment on a university-scale system, we demonstrate post-acceleration of laser-driven protons from a flat foil at a rate of 0.5 GeV m −1 , already beyond what can be sustained by conventional accelerator technologies, with dynamic beam collimation and energy selection. These results open up new opportunities for the development of extremely compact and cost-effective ion accelerators for both established and innovative applications.