Laser-driven shock acceleration of monoenergetic ion beams

TL;DR

This paper demonstrates that monoenergetic ion beams can be generated using laser-driven collisionless shocks in plasma, with potential energies up to 200 MeV using current laser technology.

Contribution

It introduces a novel method for producing high-quality monoenergetic ion beams via shock acceleration in a decaying plasma profile, supported by theory and simulations.

Findings

Monoenergetic ion beams achieved through laser-driven shocks.

Ion energies up to approximately 200 MeV with 100 TW lasers.

Conditions for high-quality ion beam acceleration identified.

Abstract

We show that monoenergetic ion beams can be accelerated by moderate Mach number collisionless, electrostatic shocks propagating in a long scale-length exponentially decaying plasma profile. Strong plasma heating and density steepening produced by an intense laser pulse near the critical density can launch such shocks that propagate in the extended plasma at high velocities. The generation of a monoenergetic ion beam is possible due to the small and constant sheath electric field associated with the slowly decreasing density profile. The conditions for the acceleration of high-quality, energetic ion beams are identified through theory and multidimensional particle-in-cell simulations. The scaling of the ion energy with laser intensity shows that it is possible to generate $\sim 200$ MeV proton beams with state-of-the-art 100 TW class laser systems.