Self-modulation of long electron beams in plasma at PITZ

Beam-driven plasma wakefield acceleration has generated a high scientific interest since it was experimentally proven that electrons can be accelerated up to energies close to 100 GeV in less than a meter of propagation in plasma. Recently, it has been proposed to use the high energetic proton beams from the CERN SPS to drive a plasma wave which is able to accelerate electron beams to TeV energy regime. The whole project relies on the fact that a long proton bunch (L>λp) is self-modulated through its propagation in plasma, splitting itself in ultrashort sub-bunches of length ∝λp which resonantly drive the plasma wave. The Photo Injector Test facility at DESY, Zeuthen site (PITZ), offers the unique possibility to study and demonstrate the self-modulation of long electron bunches in plasma. A set of numerical simulations with the particle-in-cell code Osiris have been carried out to optimize some of the parameters of the experiment like the electron bunch profile, the plasma density and the propagation length in plasma, and constrain other physical effects which can spoil the optimal excitation of the plasma wave like dephasing, hosing instability and plasma density perturbations.