Proton acceleration in underdense plasma by ultraintense Laguerre–Gaussian laser pulse

Abstract

A three-dimensional (3D) particle-in-cell (PIC) simulation is used to investigate witness proton acceleration in underdense plasma with a short intense Laguerre–Gaussian (LG) laser pulse. Driven by the LG10 laser pulse, a special bubble with an electron pillar on the axis is formed in which protons can be well confined by the generated transversal focusing field and accelerated by the longitudinal wakefield. The risk of scattering prior to acceleration with a Gaussian laser pulse in underdense plasma is avoided, and protons are accelerated stably to much higher energy. In the simulation, a proton beam has been accelerated to 7 GeV from 1 GeV in underdense tritium plasma driven by a 2.14 × 1022 W cm−2 LG10 laser pulse.