A Multibunch Plasma Wakefield Accelerator

We investigate a plasma wakefield acceleration scheme where a train of electron microbunches feeds into a high density plasma. When the microbunch train enters such a plasma that has a corresponding plasma wavelength equal to the microbunch separation distance, a strong wakefield is expected to be resonantly driven to an amplitude that is at least one order of magnitude higher than that using an unbunched beam. PIC simulations have been performed using the beamline parameters of the Brookhaven National Laboratory Accelerator Test Facility operating in the configuration of the STELLA inverse free electron laser (IFEL) experiment. A 65 MeV electron beam is modulated by a 10.6 μm CO
2
laser beam via an IFEL interaction. This produces a train of ∼ 90 microbunches separated by the laser wavelength. In this paper, we present both a simple theoretical treatment and simulation results that demonstrate promising results for the multibunch technique as a plasma-based accelerator.