The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
TY - CPAPER AU - Schalwat, M. AU - Barbanotti, S. AU - Daniel, A. AU - Hintz, H. AU - Jensch, K. AU - Matheisen, A. AU - Saegebarth, S. AU - Schilling, P. AU - Schmidt, A. TI - Exchange and Repair of Titanium Service Pipes for the EXFEL Series Cavities J2 - Proc. of International Conference on RF Superconductivity (SRF2015), Whistler, BC, Canada, Sept. 13-18, 2015 AB - Longitudinally-welded 72 mm ID service pipes (HSP) made from titanium grade 2 is used by the two suppliers of the helium tanks for the EU-XFEL accelerator. From the perspective of the PED DESY is legally designated as the manufacturer and is responsible for conformity to all relevant codes. During module assemblies at CEA Saclay the orbital welds of the interconnection bellows between cavities showed pores with dimensions outside the specifications set by DESY. These welds needed to be redone which caused a project delay of several months. The X-ray examination of the HSP showed that the pipes already exhibited many out-of- DESY spec pores in the longitudinal welds and were most likely the main cause of the problems in the orbital welds. It was decided to replace the extremities of the service pipes with seamless titanium tubes both on “naked” helium tanks as well as on tanks with cavities already welded in. At DESY more than 750 service pipes were exchanged over a period of 2 years. The qualification of the repair line according to PED regulation and the prove with RF test at 2 K that the repairs do not influence the high performance of the s.c. cavities were done. PB - JACoW CY - Geneva, Switzerland SP - 1122 EP - 1126 KW - cavity KW - alignment KW - linac KW - cryomodule KW - SRF DA - 2015/12 PY - 2015 SN - 978-3-95450-178-6 DO - 10.18429/JACoW-SRF2015-THPB025 UR - http://srf2015.vrws.de/papers/thpb025.pdf ER -