Staged laser acceleration of high quality protons from a tailored plasma

TL;DR

This paper proposes a two-stage laser-driven proton acceleration scheme using tailored plasma profiles, achieving high-energy, low-divergence, quasi-monoenergetic proton beams with significant charge and energy up to hundreds of MeV.

Contribution

It introduces a novel staged acceleration method combining wakefield pre-acceleration and shock acceleration in tailored plasma, enhancing proton beam quality and energy.

Findings

Proton beams with few tens of percent energy spread produced.

Proton beams with divergence of a few degrees.

Achieved proton energies up to several hundreds of MeV.

Abstract

A new scheme of proton acceleration from a laser-driven near-critical-density plasma is proposed. Plasma with a tailored density profile allows a two-stage acceleration of protons. The protons are pre-accelerated in the laser-driven wakefields, and are then further accelerated by the collisionless shock, launched from the rear side of the plasma. The shock has a small transverse size, and it generates a strong space-charge field, which defocuses protons in such a way, that only those protons with the highest energies and low energy spread remains collimated. Theoretical and numerical analysis demonstrates production of high-energy proton beams with few tens of percents energy spread, few degrees divergence and charge of few nC. This scheme indicates the efficient generation of quasi-monoenergetic proton beams with energies up to several hundreds of MeV with PW-class ultrashort lasers.