Prospects of laser-wakefield electron beams as drivers and witness for plasma wakefield acceleration

by Prof. Stefan Karsch (Fakultät für Physik Ludwig-Maximilians-Universität München and Max-Planck-Institut für Quantenoptik)

Tuesday 19 Jul 2016, 16:15 → 17:15 Europe/Berlin

Auditorium (MPI fuer Physik)

Laser-wakefield acceleration (LWFA) is an established technique for high-gradient electron acceleration and conceptually very similar to plasma-wakefield acceleration (PWFA), just swapping the beam driver for an intense laser pulse. It has been demonstrated by a large number of university-sized laboratories around the world, but its main limitation is the lower-than-c group velocity of the driving laser pulse in the plasma medium. This causes an accelerated electron beam to eventually overtake the driving laser and subsequently loose its energy. On the plus side, LWFA beams are comparably easy to generate, not requiring a national-lab-scale RF accelerator, their ultrashort duration of a few fs and multi-kA current. As such, they seem to be an ideal driver for small-scale PWFA model experiments, allowing to study the basic experimental challenges of PWFA without having to apply for limited access to CERN, DESY or SLAC. Likewise, they offer interesting properties as a witness bunch for large-scale PWFA experiments, especially where ultrashort electron beams are not already present like in AWAKE. Finally, laser-based wakefield diagnostics also apply to beam-driven wakefields, opening up a wide range of synergies. We will discuss LWFA-beam driven wake generation, controllable driver-witness generation and give an introduction to the new CALA laboratory at Garching.