Proton array focused by a laser-irradiated mesh

Abstract

We present a technique on focusing laser-driven proton beams in an array pattern by employing a copper mesh irradiated by a separate, intense laser pulse. Transient fields are generated on the mesh following the intense interaction. Under the combined effect of collisional scattering and electrical deflections from the mesh, a laser-driven proton beam is split into multiple focused beams with a high density of ∼4 × 109/cm2 after propagation through the charged-up mesh. The particle density within the focused beamlets is up to ∼11 times the initial density of the proton beam. Multiple beam focusing through this approach may open routes for proton beam conditioning, leading to opportunities for multi-beam applications, such as tomographic radiography and proton implantation.