Generation of quasi-monoenergetic proton beams via quantum radiative compression

TL;DR

This paper introduces a quantum radiative compression technique that uses laser-plasma interactions to produce dense, quasi-monoenergetic proton beams with high energy and low spread, suitable for advanced applications.

Contribution

The study proposes a novel quantum radiative compression method for post-processing laser-accelerated proton beams, achieving high density and low energy spread in proton beams.

Findings

Proton beams with GeV energies and a few percent energy spread can be generated.

The method produces proton numbers around 10^10, suitable for practical applications.

Simulations show feasibility with near-future laser facilities.

Abstract

Dense high-energy monoenergetic proton beams are vital for wide applications, thus modern laser-plasma-based ion acceleration methods are aiming to obtain high-energy proton beams with energy spread as low as possible. In this work, we put forward a quantum radiative compression method to post-compress a highly accelerated proton beam and convert it to a dense quasi-monoenergetic one. We find that when the relativistic plasma produced by radiation pressure acceleration collides head-on with an ultraintense laser beam, large-amplitude plasma oscillations are excited due to quantum radiation-reaction and the ponderomotive force, which induce compression of the phase space of protons located in its acceleration phase with negative gradient. Our three-dimensional spin-resolved QED particle-in-cell simulations show that hollow-structure proton beams with a peak energy $\sim$ GeV, relative energy spread of few percents and number $N_p\sim10^{10}$ (or $N_p\sim 10^9$ with a $1\%$ energy spread) can be produced in near future laser facilities, which may fulfill the requirements of important applications, such as, for radiography of ultra-thick dense materials, or as injectors of hadron colliders.