Impact of He+N2 concentration on self-modulated laser wakefield acceleration driven by pulses of a few TW

Abstract

Laser wakefield electron acceleration with ionization injection has rarely been studied in the low-power, self-modulated case. We performed simulations of such regimes using a mixture of He and N2 gases and driven by laser pulses with peak powers around 1 TW. Analyses show the generation of electron bunches with an average energy of up to 70 MeV, an energy spread as low as 18%, and an emittance as good as a fraction of a mm mrad. The obtained electron beam parameters lead to several trade-offs as a function of N2 concentration, allowing for many different designs.