TNSA based proton acceleration by two oblique laser pulses in the presence of an axial magnetic field

TL;DR

This study uses 2D PIC simulations to show that combining two oblique laser pulses with an axial magnetic field significantly enhances proton cutoff energies in TNSA, outperforming normal incidence configurations.

Contribution

It demonstrates the combined effect of oblique laser pulses and an axial magnetic field on proton acceleration, a novel approach in TNSA scheme.

Findings

Oblique laser pulses with magnetic field increase proton cutoff energy.

Magnetic field reduces electron divergence, improving sheath field.

Oblique incidence outperforms normal incidence in energy enhancement.

Abstract

A recently proposed strategy to boost the proton/ion cutoff energy in the target normal sheath acceleration scheme employs two obliquely incident laser pulses simultaneously irradiating the flat target rather than a single normally incident laser pulse of twice the pulse energy. Moreover, the presence of an externally applied magnetic field along the normal of the target's rear surface is known to reduce the angular divergence of hot electrons which results in a more efficient sheath field at the target rear leading to increased cutoff energy of accelerated protons/ions. In the present work, we employ two-dimensional Particle-In-Cell (PIC) simulations to examine, in detail, the effect of such a magnetic field on the cutoff energy of protons/ions in the cases of normal as well as oblique incidence of the laser pulse on a flat target. It is shown that the two-oblique-pulse configuration combined with an external magnetic field results in a stronger enhancement of the cutoff energies as compared to the normal incidence case.