• D. Proch
  DESY, Hamburg

CARE (Coordinated Accelerator Research in Europe) describes a collaboration which aimed at improvements of existing accelerator facilities. It was supported by the European commission in the framework of FP6. The dominant R&D activities within CARE were related to superconducting accelerator systems, especially TTF / FLASH. This report will describe the different SRF activities (cavity fabrication technologies, surface treatments and inspection, industrialisation of electro-polishing, coupler and tuner developments, Low Level RF concepts and beam diagnostics). The most important advances will be high lighted and the impact to new or future SRF accelerator systems will be concluded.

Slides

Talk

• G. Kreps, A. Goessel, D. Kostin, W.-D. Möller, D. Proch, K. Twarowski
  DESY, Hamburg

The CW test of the 9 cell TESLA-type cavity in liquid helium bath at 2 K gives the cavity performance data for the cavity acceptance. The excitation of parasitic modes of the operating pass band is an error source for the cavity gradient and quality factor determination. The excitation of the parasitic modes in the operating pass band has been observed in 81 CW cold tests out of 170 and in 41 cavities under test out of 65 since 2006. The ramp up time of the parasitic mode depends strongly on the Qload of the input antenna. Some modes are exited in the combination with electron emission but others (7/9 Pi) have large amplitude without any attribute of field emission (x-ray or e^- current at pick up). The growing up function of parasitic modes is different from the cavity response on the outside excitation but it describes a positive feed-back system. The relation of this effect to the field emission as well as to other test parameters has been investigated and is described in this paper.

Poster

• J.H. Thie, A. Goessel, J. Iversen, D. Klinke, G. Kreps, W.-D. Möller, C. Mueller, D. Proch
  DESY, Hamburg
• R.H. Carcagno, T.N. Khabiboulline, S. Kotelnikov, A. Makulski, R. Nehring, J.M. Nogiec, M.C. Ross, W. Schappert
  Fermilab, Batavia

A semi-automatic cavity tuning machine is used at DESY since 15 years to tune the field flatness and concentricity of the TESLA shape 9 cell cavities for FLASH. Based on this experience a further development work was done in a collaboration effort among FNAL, DESY and KEK to support the high throughput cavity fabrication necessary for the European XFEL and other SRF based future projects. Two of the four machines will be delivered to and operated by the cavity vendors for the tuning of the XFEL cavities. We describe the mechanical design and functionality of these machines and discuss the safety aspects for the operation at the industry.

Poster

• P.A. McIntosh, R. Bate, C.D. Beard, S.M. Pattalwar
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• S.A. Belomestnykh, E.P. Chojnacki, Z.A. Conway, G.H. Hoffstaetter, P. Quigley, V. Veshcherevich
  CLASSE, Ithaca, New York
• A. Büchner, F.G. Gabriel, P. Michel
  FZD, Dresden
• M.A. Cordwell, D.M. Dykes, J. Strachan
  STFC/DL, Daresbury, Warrington, Cheshire
• J.N. Corlett, D. Li, S.M. Lidia
  LBNL, Berkeley, California
• T. Kimura, T.I. Smith
  Stanford University, Stanford, Califormia
• S.R. Koscielniak, R.E. Laxdal
  TRIUMF, Vancouver
• M. Liepe, H. Padamsee, J. Sears, V.D. Shemelin
  Cornell University, Ithaca, New York
• D. Proch, J.K. Sekutowicz
  DESY, Hamburg

The collaborative development of an optimised cavity/cryomodule solution for application on ERL facilities has now progressed to final assembly and testing of the cavity string components and their subsequent cryomodule integration. This paper outlines the testing and verification processes for the various cryomodule sub-components and details the methodology utilised for final cavity string integration. The paper also highlights the modifications required to integrate this new cryomodule into the existing ALICE cryo-plant facility at Daresbury Laboratory.