Beam loading limited high peak current laser wakefield accelerators

Laser wakefield accelerators (LWFA) can potentially generate high-peak current electron beams at the order of a few tens of kiloAmperes which are very attractive as drivers for compact secondary radiation sources ranging from THz up togamma-ray or as drivers for beam driven wakefield accelerators (PWFA).
The phenomenon of beam loading affects the amount of trapped charge inside the plasma cavity while influencing the final beam parameters, i.e., transverse emittance and maximum attainable energy and spread.
We experimentally investigate these effects in the self-truncated ionization injection scheme (STII) by loading several hundreds of pC of charge into the wakefield within a monoenergetic bunch. We explore the influence of beam loading on electron energy, energy spread and beam divergence. We show that beam quality is maintained up to an estimated peak-current of 30 kA, which is an order of magnitude higher than can be reached in current state-of-the-art conventional electron accelerators.