• D. Kostin, W.-D. Möller, J.K. Sekutowicz, K. Twarowski
  DESY, Hamburg

TESLA 9-cell cavity was designed a decade ago for pulse operation at duty factor of a few percents. Recently, numerous coherent and synchrotron light sources projects base their driving superconducting linacs on this design assuming operation in a continuous wave (CW) mode at rather high gradients. We have performed CW tests of a standard 9-cell TESLA cavities installed in helium vessel and fully equipped with the standard TESLA-TTF auxiliaries, main coupler and both Higher Order Mode (HOM) couplers in the horizontal test cryostat to find out a limit in the CW operation. Tests details and results are presented and discussed.

Poster

• T. Kamps, W. Anders, A. Frahm, J. Knobloch, O. Kugeler, A. Neumann, T. Quast, M. Schenk, M. Schuster
  Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Elektronen-Speicherring BESSY II, Berlin
• M. Dirsat
  Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin
• P. Kneisel
  JLAB, Newport News, Virginia
• R. Nietubyc
  The Andrzej Soltan Institute for Nuclear Studies, Centre Swierk, Swierk/Otwock
• T. Rao, J. Smedley
  BNL, Upton, Long Island, New York
• J.K. Sekutowicz
  DESY, Hamburg
• J. Teichert
  FZD, Dresden
• I. Will
  MBI, Berlin

In this paper we describe the R&D roadmap at HZB for the development of a high-brightness, high average current SRF electron gun for an energy-recovery linac based synchrotron radiation source.

• P. Kneisel
  JLAB, Newport News, Virginia
• J.K. Sekutowicz
  DESY, Hamburg

We have in the past reported about our efforts to develop a flangeable coaxial coupler for both HOM and fundamental coupling for 9-cell ILC-type cavities. The design of the coupler was done in a way, that the rf magnetic fields at the flange connection were minimized and only a field of <5 mT would be present for a magnetic field of 160 mT ( Eacc ~ 35 MV/m) in the cavity. Even though we achieved reasonably high Q-values at low field, the cavity/coupler combination was limited to only ~ 7 MV/m in the cavity, where a thermally initiated degradation occurred. We believed that this limitation was caused by poor cooling of the shorting plate in the coaxial coupler; therefore, we have improved the cooling conditions by drilling radial cooling channels into the shorting plate. This paper reports about our experiences with the modified conditions.

• 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.