SRF2011 - List of Authors (Schalwat, M.)

Paper	Title	Page
TUPO018	Update of the DESY Infrastructure for Cavity Preparation	401
	M. Schalwat, K. Escherich, N. Krupka, A. Matheisen, B. Petersen, N. Steinhau Kühl DESY, Hamburg, Germany
	The clean room is the main infrastructure for preparation of superconducting cavities at DESY, which was set up in the early 90th of the last century. This clean room was completely renovated in 2009. The ground plan of clean room class ISO 4 was enlarged from 20 to 53 m² and the areas of ISO 7 of the old clean room were upgraded to ISO 6 and ISO 5 standard. Areas for ultrasonic cleaning, ultrapure water rinsing and chemical surface treatment were upgraded to ISO 4 standards. Multiple vacuum connections were installed to reduce movement of cavities. A 120oC heating chamber was connected to the ISO 4 assembly area and allows the in situ bake out of multi cell super conducting resonators. For industrial cavity production it was shown that a high pressure rinsing unit driven by a turbine pump allows feeding several high pressure rinsing stands in parallel. For cost reduction of ultra pure water production and for increase of the amount of water in the cavity preparation cycle, a recirculation of rinsing water is under commissioning. Fixtures and tools for the assembly of the Beam position monitor and Quadrupol units (BQU) for the XFEL modules are installed and commissioned.

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

Update of the DESY Infrastructure for Cavity Preparation

401

M. Schalwat, K. Escherich, N. Krupka, A. Matheisen, B. Petersen, N. Steinhau Kühl
DESY, Hamburg, Germany

The clean room is the main infrastructure for preparation of superconducting cavities at DESY, which was set up in the early 90th of the last century. This clean room was completely renovated in 2009. The ground plan of clean room class ISO 4 was enlarged from 20 to 53 m² and the areas of ISO 7 of the old clean room were upgraded to ISO 6 and ISO 5 standard. Areas for ultrasonic cleaning, ultrapure water rinsing and chemical surface treatment were upgraded to ISO 4 standards. Multiple vacuum connections were installed to reduce movement of cavities. A 120oC heating chamber was connected to the ISO 4 assembly area and allows the in situ bake out of multi cell super conducting resonators. For industrial cavity production it was shown that a high pressure rinsing unit driven by a turbine pump allows feeding several high pressure rinsing stands in parallel. For cost reduction of ultra pure water production and for increase of the amount of water in the cavity preparation cycle, a recirculation of rinsing water is under commissioning. Fixtures and tools for the assembly of the Beam position monitor and Quadrupol units (BQU) for the XFEL modules are installed and commissioned.

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.