Author: Mehrling, T.J.
Paper Title Page
Electron Beam De-chirping in a Plasma  
  • V. Wacker, C. Behrens, J. Grebenyuk, A. Martinez de la Ossa, T.J. Mehrling, J. Osterhoff
    DESY, Hamburg, Germany
  Beam-driven plasma wakefield acceleration (PWFA) is a promising and evolving technique for next-generation, compact light sources. By propagating a dense drive-beam through a plasma, expelled plasma electrons can excite wakefields supporting electric fields in excess of 10 GV/m. Like in a conventional radio-frequency cavity, the acceleration strongly depends on the injection phase with respect to the wakefield. Different injection schemes have been proposed recently, all having in common a significant time-energy correlation, the so-called energy-chirp. These energy-chirps typically lead to energy bandwidths of up to 10% in PWFA, hampering efficient beam transport and eventually any kind of free-electron laser (FEL) application. Analogous to short-range wakefields generated by electron beams in a resistive beam pipe, the wakefields generated by the electron beam in a plasma can be used to compensate the initial energy-chirp. Here we present the idea of electron beam de-chirping in a plasma and show the conditions for optimal de-chirping with simultaneous beam quality preservation. This is the basis for efficient beam transport and thus paves the way for FELs utilizing PWFA.