Laser ion acceleration by using the dynamic motion of a target

TL;DR

This paper demonstrates through simulations that using a dynamic, moving target layer in laser-driven proton acceleration significantly enhances proton energy and beam quality, achieving 200 MeV with minimal energy spread.

Contribution

It introduces a novel approach leveraging the target's dynamic motion to improve proton acceleration efficiency and beam quality in laser-plasma interactions.

Findings

Protons reach up to 200 MeV energy.

A 2% energy spread is achieved.

Dynamic target motion enhances acceleration efficiency.

Abstract

Proton acceleration by using a 620-TW, 18-J laser pulse of peak intensity of $5\times 10^{21}$ W/cm$^{2}$ irradiating a disk target is examined using three-dimensional particle-in-cell simulations. It is shown that protons are accelerated efficiently to high energy for a "light" material in the first layer of a double-layer target, because a strongly inhomogeneous expansion of the first layer occurs by a Coulomb explosion within such a material. Moreover, a large movement of the first layer for the accelerated protons is produced by radiation-pressure-dominant acceleration. A time-varying electric potential produced by this expanding and moving ion cloud accelerates protons effectively. In addition, using the best material for the target, one can generate a proton beam with an energy of 200 MeV and an energy spread of 2$%$.