Study of the Electron Beam Transfer Line for the AWAKE RUN II Experiment at CERN

Proton Beam-Driven Plasma Wakefield Accelerator (PBD-PWFA) has been actively investigated at CERN within the AWAKE experiments to study the electron beam acceleration using plasma wake fields of the order of GV/m. In the AWAKE RUN 1 experiment an electron beam with an energy of 19 MeV and a bunch length of 2.2 ps rms has been used for the first demonstration of electron beam acceleration in the plasma wake fields. It has been observed that the energy gain of the electron beam is up to 2 GeV, and electron capture efficiency is few percent. Higher capturing efficiency and emittance preservation could be achieved by making the electron beam short enough to be injected only into the acceleration and focusing phase of the plasma wake fields. The electron accelerator needs to be upgraded for AWAKE RUN 2 experiments to obtain a bunch length less than 100 fs which corresponds to a quarter of the plasma wavelength. Planned electron beam parameters for the AWAKE RUN 2 are a beam charge of 100 pC, and a beam energy larger than 50 MeV. In this paper, we show the electron beam parameters for RUN 2, and the parameters of the transfer line such as Twiss parameters, beam envelope, and emittance.