LINAC2014 - List of Keywords (superconductivity)

Paper	Title	Other Keywords	Page
MOPP016	Extracting Superconducting Parameters from Surface Resistivity by Using Inside Temperature of SRF Cavities	cavity, accelerating-gradient, SRF, electron	80
	G.M. Ge, G.H. Hoffstaetter, M. Liepe, H. Padamsee, V.D. Shemelin Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	The surface resistance of an RF superconductor depends on the surface temperature, the residual resistance and various superconductor parameters. These parameters can be determined by measuring the quality factor of a SRF cavity in helium-baths of different temperatures. The surface resistance can be computed from Q0 for any cavity geometry, however it is less simple to determine the temperature of the surface when only the temperature of the helium bath is known. Traditionally, it was approximated that the surface temperature on the inner surface of the cavity is the same as the temperature of the bath. This is a good approximation at small RF-field losses on the surface, but to determine the field dependence of Rs, one cannot be restricted to small field losses. Here we show how computer simulations can be used to determine the inside temperature so that Rs(Tin) can then be used to extract superconductor parameters. The computer code combines the well-known programs HEAT and SRIMP. We find that the error of the incorrect fitting method is about 10% at high RF-fields.

THPP021	Analysis of the RF Test Results from the On-going Accelerator Cavity Production for the European XFEL	cavity, SRF, linac, operation	879
	D. Reschke, S. Aderhold, V. Gubarev, J. Schaffran, N.J. Walker DESY, Hamburg, Germany L. Monaco INFN/LASA, Segrate (MI), Italy Y. Yamamoto KEK, Ibaraki, Japan
	Funding: The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no 283745 (CRISP) The main Linac of the European XFEL will consist of 100 superconducting accelerator modules, operated at an average design gradient of 23.6 MV/m. The fabrication by industry (which includes chemical surface preparation) of the required 800 superconducting cavities is now in full swing, with approximately 400 cavities having been delivered to date. In this interim report, we present an analysis of the RF acceptance tests amassed so far.

Paper

Title

Other Keywords

Page

MOPP016

Extracting Superconducting Parameters from Surface Resistivity by Using Inside Temperature of SRF Cavities

cavity, accelerating-gradient, SRF, electron

80

G.M. Ge, G.H. Hoffstaetter, M. Liepe, H. Padamsee, V.D. Shemelin
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

The surface resistance of an RF superconductor depends on the surface temperature, the residual resistance and various superconductor parameters. These parameters can be determined by measuring the quality factor of a SRF cavity in helium-baths of different temperatures. The surface resistance can be computed from Q0 for any cavity geometry, however it is less simple to determine the temperature of the surface when only the temperature of the helium bath is known. Traditionally, it was approximated that the surface temperature on the inner surface of the cavity is the same as the temperature of the bath. This is a good approximation at small RF-field losses on the surface, but to determine the field dependence of Rs, one cannot be restricted to small field losses. Here we show how computer simulations can be used to determine the inside temperature so that Rs(Tin) can then be used to extract superconductor parameters. The computer code combines the well-known programs HEAT and SRIMP. We find that the error of the incorrect fitting method is about 10% at high RF-fields.

THPP021

Analysis of the RF Test Results from the On-going Accelerator Cavity Production for the European XFEL

cavity, SRF, linac, operation

879

D. Reschke, S. Aderhold, V. Gubarev, J. Schaffran, N.J. Walker
DESY, Hamburg, Germany
L. Monaco
INFN/LASA, Segrate (MI), Italy
Y. Yamamoto
KEK, Ibaraki, Japan

Funding: The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no 283745 (CRISP)
The main Linac of the European XFEL will consist of 100 superconducting accelerator modules, operated at an average design gradient of 23.6 MV/m. The fabrication by industry (which includes chemical surface preparation) of the required 800 superconducting cavities is now in full swing, with approximately 400 cavities having been delivered to date. In this interim report, we present an analysis of the RF acceptance tests amassed so far.