Monoenergetic electron beams from relativistic laser-plasma interaction

Plasmas are attractive media for the next generation of compact particle accelerators because they can sustain electric fields larger than those in conventional accelerators by three orders of magnitude. However, until now, plasma-based accelerators have produced relatively poor quality electron beams even though for most practical applications, high quality beams are required. In particular, beams from plasma-based accelerators have a large divergence and very large energy spreads, meaning that different particles travel at different speeds. The combination of these two problems makes it difficult to utilize these beams. Here, we demonstrate the production of high quality and high energy electron beams from laser-plasma interaction: in a distance of 3 mm, a very collimated and quasi-monoenergetic electron beam is emitted with a 1 nanocoulomb charge at 170 MeV +/-20 MeV. This dramatic increase in performance occurs when the laser pulse is able to drive a plasma bubble. The plasma bubble is an ideal structure for trapping electrons and accelerating them to a single energy. In this talk, we will review the different regimes of electron acceleration and we will show how enhanced performances can be reached with state-of-the-art ultrashort laser systems