SRF2011 - List of Authors (Saegebarth, S.)

Paper	Title	Page
TUPO041	Investigation on Cavity String Assembly and Repair	472
	A. Matheisen, B. Horst, van der, S. Saegebarth, P. Schilling, M. Schmökel, N. Steinhau Kühl, H. Weitkämper DESY, Hamburg, Germany
	At DESY several cavity strings for modules of the FLASH accelerator and studies on XFEL prototypes are completed. In some modules cavities have been exchanged for upgrade of applicable module gradients or exchange of resonators showing performance degradation in the module test. Assembly and repair sequences and quality control plans for cavity string are developed and applied. From module string PXFEL3 six out of eight cavities are removed and handed over to CEA Saclay for training of string and module assembly. On two of these cavities the procedures for assembly and exchange of cavities in cavity strings are crosschecked. These cavities are tested at 2 K as removed from string without additional treatments to cross check assembly and repair sequences.

TUPO045	Investigations to Understand the Origin of Degradation of Super Conducting Cavities found in Acceleration Modules at DESY	486
	A. Matheisen, B. Horst, van der, D. Kostin, N. Krupka, S. Saegebarth, M. Schalwat, P. Schilling, M. Schmökel, H. Weitkämper DESY, Hamburg, Germany
	In the last decade the degradation of cavity acceleration gradients is observed frequently in module RF tests, after the assembly and installation of complete accelerator modules. In some cases no explanation for these degradations could be found from quality control records, assembly procedure protocols or notes from observers. On the PXFEL3 module quench limitations without indication of field emission loading is observed at two cavities. Boundary conditions like storage of resonators, cleaning process for ISO 4 clean room as well as the assembly processes and handling of the resonators are under investigation. The two degraded cavities of module PXFEL 3 are removed from the cavity string and studied intensively. The actual status of our research is presented.

Paper

Title

Page

Investigation on Cavity String Assembly and Repair

472

A. Matheisen, B. Horst, van der, S. Saegebarth, P. Schilling, M. Schmökel, N. Steinhau Kühl, H. Weitkämper
DESY, Hamburg, Germany

At DESY several cavity strings for modules of the FLASH accelerator and studies on XFEL prototypes are completed. In some modules cavities have been exchanged for upgrade of applicable module gradients or exchange of resonators showing performance degradation in the module test. Assembly and repair sequences and quality control plans for cavity string are developed and applied. From module string PXFEL3 six out of eight cavities are removed and handed over to CEA Saclay for training of string and module assembly. On two of these cavities the procedures for assembly and exchange of cavities in cavity strings are crosschecked. These cavities are tested at 2 K as removed from string without additional treatments to cross check assembly and repair sequences.

TUPO045

Investigations to Understand the Origin of Degradation of Super Conducting Cavities found in Acceleration Modules at DESY

486

A. Matheisen, B. Horst, van der, D. Kostin, N. Krupka, S. Saegebarth, M. Schalwat, P. Schilling, M. Schmökel, H. Weitkämper
DESY, Hamburg, Germany

In the last decade the degradation of cavity acceleration gradients is observed frequently in module RF tests, after the assembly and installation of complete accelerator modules. In some cases no explanation for these degradations could be found from quality control records, assembly procedure protocols or notes from observers. On the PXFEL3 module quench limitations without indication of field emission loading is observed at two cavities. Boundary conditions like storage of resonators, cleaning process for ISO 4 clean room as well as the assembly processes and handling of the resonators are under investigation. The two degraded cavities of module PXFEL 3 are removed from the cavity string and studied intensively. The actual status of our research is presented.