Enhanced target normal sheath acceleration using colliding laser pulses

TL;DR

This paper demonstrates that splitting a laser pulse into two colliding parts significantly enhances proton acceleration from laser-solid interactions, nearly doubling proton energies and increasing proton numbers, with robust experimental potential.

Contribution

The study introduces a novel multi-pulse scheme that enhances target normal sheath acceleration by creating standing wave patterns, improving proton energies and yields.

Findings

Proton energies nearly doubled with the scheme.

Proton numbers increased fivefold.

Enhancement is robust across incidence angles.

Abstract

Laser-solid interaction can lead to the acceleration of protons to tens of MeV. Here, we show that a strong enhancement of this acceleration can be achieved by splitting the laser pulse to two parts of equal energy and opposite incidence angles. Through the use of two- and three-dimensional Particle-In-Cell simulations, we find that the multi-pulse interaction leads to a standing wave pattern at the front side of the target, with an enhanced electric field and a substantial modification of the hot electron generation process. This in turn leads to significant improvement of the proton spectra, with an almost doubling of the accelerated proton energy and five-fold enhancement of the number of protons. The proposed scheme is robust with respect to incidence angles for the laser pulses, providing flexibility to the scheme, which should facilitate its experimental implementation.