Characterization of self-injected electron beams from LWFA experiments at SPARC_LAB

TL;DR

This paper characterizes self-injected electron beams generated by laser wakefield acceleration at SPARC_LAB, demonstrating electron energies up to 350 MeV and beam charges of 50-100 pC using a high-power laser system.

Contribution

It provides detailed experimental characterization of self-injected electron beams in LWFA at SPARC_LAB, highlighting specific beam parameters achieved with a 1.5 J laser pulse.

Findings

Electron energies up to 350 MeV achieved.

Beam charge in the range of 50-100 pC.

Plasma density around 6 x 10^{18} cm^{-3}.

Abstract

The plasma-based acceleration is an encouraging technique to overcome the limits of the accelerating gradient in the conventional RF acceleration. A plasma accelerator is able to provide accelerating fields up to hundreds of $GeV/m$, paving the way to accelerate particles to several MeV over a short distance (below the millimetre range). Here the characteristics of preliminary electron beams obtained with the self-injection mechanism produced with the FLAME high-power laser at the SPARC_LAB test facility are shown. In detail, with an energy laser on focus of $1.5\ J$ and a pulse temporal length (FWHM) of $40\ fs$, we obtained an electron plasma density due to laser ionization of about $6 \times 10^{18}\ cm^{-3}$, electron energy up to $350\ MeV$ and beam charge in the range $(50 - 100)\ pC$.