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

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 f s, we obtained an electron plasma density due to laser ionization of about 6 × 1018 cm−3 , electron energy up to 350 MeV and beam charge in the range (50 − 100) pC