AWAKE Proton Beam Commissioning

AWAKE will be the first proton driven plasma wakefield acceleration experiment worldwide. The facility is located in the former CNGS area at CERN and includes a proton, laser and electron beam line merging in a 10 m long plasma cell, which is followed by the experimental diagnostics. In the first phase of the AWAKE physics program, which started at the end of 2016, the effect of the plasma on a high energy proton beam is being studied. A proton bunch is expected to experience the so called self-modulation instability, which leads to the creation of micro-bunches within the long proton bunch. The plasma channel is created in a rubidium vapor via field ionization by a TW laser pulse. This laser beam has to overlap with the proton beam over the full length of the plasma cell, resulting in tight requirements for the stability of the proton beam at the plasma cell in the order of 0.1 mm. In this paper the beam commissioning results of the 810 m long transfer line for proton bunches with $3 \cdot 10^{11}$ protons/bunch and a momentum of 400 GeV/c will be presented with a focus on the challenges of the parallel operation of the laser and proton beam.