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SRF2003 Show Abstract

Title Processing of TTF-cavities at DESY
Type Poster cavity design / fabrication / treatment
Abstract The superconducting (s.c.) 9 cell-cavities of TESLA /TTF design are produced by industry. The preparation by surface treatments like chemical etching (buffered chemical polishing /BCP), Electro-polishing (E.P.), high pressure rinsing (HPR) and the assembly take place inside the TTF cleanroom. At first the cavities are treated without their individual Helium vessel (He-vessel) for the acceptance test. This test is done vertically in cw. mode operation at 2 K. After meeting the specification (Eacc > 25MV/m; Qo >5 *10 9), the cavities are welded into their He-vessel. Also this is a complex procedure with several steps and up to now standardized for BCP-cavities only. After this welding process the BCP treated cavities get a final chemical etch. This final preparation step can not be applied to electro-polished (E.P.) resonators. Here a HPR rinse is done for preparation of module assembly. Finally eight cavities, each equipped with pick up antennas for higher order mode (HOM) absorption, field probe and the power coupler, are connected. A beam position monitor (BPM) and one s.c. quadrupole complete the TTF module string assembly. The actual cavity preparation process at DESY will be represented in flow diagrams. The difference between the He-vessel-welding-procedure of etched cavities and the first attempt for E.P. cavity tank-welding will be shown. We will summarize cavity preparations and cavity test results of the last year. In several cases correlations between preparation expiration and the cavity performance will be discussed.

List of authors...

Principle author first.

Last (Family) Name First Name (Initials only) Affiliation or Organization (abbreviations if possible)
Ebeling T. DESY
Bandelmann R. DESY
Escherich K. DESY
Krupka N. DESY
Matheisen A. DESY
Petersen B. DESY
Steinhau-Kuehl N. DESY

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