Superconducting cryo-modules characterization for European XFEL - LLRF tests in AMTF

Abstract

The paper describes achievements in LLRF based tests preparation for superconducting cryo-modules evaluation for European X-ray Free Electron Laser. The software for automatic cryo-modules characterization at the Accelerator Module Test Facility (AMTF) will be presented. In order to identify fundamental working parameters of the eight TESLA cavities cryomodules the scenario of several tests sequence has been proposed and implemented in AMTF. Main parameters like: cavities quenching levels verification, cavities Pi modes identification, slow and fast frequency tuners performance, fundamental power coupler performance, etc are evaluated. Basing on achieved data the decision about module acceptance for work in the linac is done. In this solution the MTCA.4 based LLRF system is used to control and verify cryo-string performance. Middle layer client servers implemented in this environment are responsible for providing tests initial conditions, testing and results archiving in the dedicated data base. Results of described tests are not only vital for module acceptance but are also important for future LLRF system set-up and configuration concerning module work in the accelerator tunnel.