Plasma Wakefield Acceleration Experiments at FACET

FACET (Facility for Advanced Accelerator Experimental Tests) is a new facility at SLAC primarily dedicated to the study of beam-driven plasma wakefield acceleration (PWFA), an advanced particle acceleration technique which can produce longitudinal electric fields that are orders of magnitude stronger than those in conventional metal structures, and can sustain those fields over a distance of meters. These features make PWFA an attractive technology for the design of future linear colliders and light sources. The experiments at FACET will roughly mimic a single stage of a plasma-based accelerator by demonstrating the uniform acceleration of a discrete electron witness bunch, increasing its energy by about 20 GeV over a distance of 1 m in a plasma wake induced by a separate driver bunch of electrons. Another major goal of FACET is to study PWFA using various combinations of positrons and electrons in the roles of driver and witness bunch for the first time.