SRF2013 - List of Authors (Schaefer, L.)

Paper	Title	Page
MOP032	Statistic to Eddy-Current Scanning of Niobium Sheets for European XFEL	171
	A. Brinkmann, S. Arnold, A. Ermakov, J. Iversen, M. Lengkeit, A. Poerschmann, L. Schaefer, W. Singer, X. Singer DESY, Hamburg, Germany
	The fabrication experiences of superconducting cavities for FLASH have shown that eddy-current scanning of the Nb-sheets foreseen for half-cells reduces the cavity failures. New eddy current devices have been developed and build together with the industry for the production of 800 pieces 1.3 GHz superconducting niobium cavities for European XFEL. More than 15.000 Nb-sheets provided by three companies have been tested by eddy-current scanning. The sheets that demonstrated local deviations of the signal have been subsequently non-destructively examined by 3d-microscope and X-Ray element analysis. The surface defects (dents, holes, scratches) are the mainly detected flaws. In addition several types of foreign material inclusions observed. Statistic concerning eddy-current signal deviation and rejection rates for each supplier will be presented.

Paper

Title

Page

Statistic to Eddy-Current Scanning of Niobium Sheets for European XFEL

171

A. Brinkmann, S. Arnold, A. Ermakov, J. Iversen, M. Lengkeit, A. Poerschmann, L. Schaefer, W. Singer, X. Singer
DESY, Hamburg, Germany

The fabrication experiences of superconducting cavities for FLASH have shown that eddy-current scanning of the Nb-sheets foreseen for half-cells reduces the cavity failures. New eddy current devices have been developed and build together with the industry for the production of 800 pieces 1.3 GHz superconducting niobium cavities for European XFEL. More than 15.000 Nb-sheets provided by three companies have been tested by eddy-current scanning. The sheets that demonstrated local deviations of the signal have been subsequently non-destructively examined by 3d-microscope and X-Ray element analysis. The surface defects (dents, holes, scratches) are the mainly detected flaws. In addition several types of foreign material inclusions observed. Statistic concerning eddy-current signal deviation and rejection rates for each supplier will be presented.