Accelerator Module Repair for the European XFEL Installation

Repair actions of different extent have been performed at 61 modules of the 100 accelerating series modules for the European XFEL to qualify them for the tunnel installation. Four modules could not be repaired in time. CEA Saclay managed to perform three major repairs in parallel to the series module integration, the residual repair actions took place at DESY Hamburg. In this paper we will give an overview on the various technical problems which required being fixed before the tunnel installation and on the repair actions performed.