Speaker: Erik Adli, Associate Professor at the Department of Physics and Technology, University of Oslo, Norway

Title : Recent progress in beam-driven plasma wakefield acceleration research

Abstract :

High-efficiency acceleration of charged particle beams at high gradients (energy gain per unit length) is necessary to achieve an affordable and compact high-energy collider for high energy physics. The beam-driven plasma wakefield accelerator is one concept being developed for this purpose. The field has recently seen a rapid experimental progress, in particular with the last few years of running of the FACET facility at SLAC.  We present the general principles of plasma wakefield acceleration, followed by key results recently obtained at FACET.  First, the acceleration of a distinct trailing bunch of electrons, at high fields, with high energy efficiency and low energy spread, was demonstrated. Positron behave very differently than electrons in the non-linear blow-out regime studied at FACET. In the experiments, a new regime for positron acceleration, where energy is efficiently transferred from the front to the rear within a single positron bunch was discovered. In the wake of the successful experiments in the US, several European laboratories, including CERN, are currently investing in plasma wakefield experiments.  We will briefly discuss these experiments as well.