IPAC2017 - List of Authors (Köszegi, J.M.)

Paper	Title	Page
MOPVA047	Investigation of Trapped Magnetic Flux in Superconducting Niobium Samples with Polarized Neutron Radiography	964
	O. Kugeler, J. Knobloch, M.M. Krzyzagorski, J.M. Köszegi, L. Riik, W. Treimer, R.F. Ziesche HZB, Berlin, Germany
	The dynamics of flux expulsion during superconducting transition and the influence of external AC magnetic fields on expulsion of trapped fields in Nb samples has been investigated with radiography using polarized neu-trons. Results of these experiments are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA047
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MOPVA048	Simulation of the Thermoelectrically Generated Magnetic Field in a SC Nine-Cell Cavity	968
	J.M. Köszegi, J. Knobloch, O. Kugeler HZB, Berlin, Germany
	Several studies showed that thermocurrents generate a magnetic field in a horizontal cavity test assembly or cryomodul, which may get trapped during the supercon-ducting phase transition. The trapped flux causes additional dissipation in the order of 1 to 10 n' during operation and can therefore significantly degrade the quality factor in a TESLA cavity. We simulated the distribution of the generated magnetic field over the whole cavity-tank system for an asymmetric temperature distribution. The asymmetry allows the field to penetrate the RF surface which would be field free in the symmetric case. The calculated results complemented a direct measurement of trapped magnetic flux inside the cavity with a small number of field probes. Finally, the obtained data was combined with RF measurements in three passband modes to determine the overall distribution of trapped magnetic flux due to thermocurrents.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA048
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MOPVA050	Setup of a Spatially Resolving Vector Magnetometry System for the Investigation of Flux Trapping in Superconducting Cavities	975
SUSPSIK099	use link to see paper's listing under its alternate paper code
	B. Schmitz, K.Alomari. Alomari, J. Knobloch, O. Kugeler, J.M. Köszegi, Y. Tamashevich HZB, Berlin, Germany
	Flux trapping is the major contribution to the residual resistance of superconducting cavities. In order to gain a better understanding of the mechanisms involved and aiming at an eventual minimization of trapped flux, a measurement setup based on AMR sensors was devised that allows for monitoring the magnetic field vector at various positions near the cavity surface. First results of the efforts are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA050
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Investigation of Trapped Magnetic Flux in Superconducting Niobium Samples with Polarized Neutron Radiography

964

O. Kugeler, J. Knobloch, M.M. Krzyzagorski, J.M. Köszegi, L. Riik, W. Treimer, R.F. Ziesche
HZB, Berlin, Germany

The dynamics of flux expulsion during superconducting transition and the influence of external AC magnetic fields on expulsion of trapped fields in Nb samples has been investigated with radiography using polarized neu-trons. Results of these experiments are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA047

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPVA048

Simulation of the Thermoelectrically Generated Magnetic Field in a SC Nine-Cell Cavity

968

J.M. Köszegi, J. Knobloch, O. Kugeler
HZB, Berlin, Germany

Several studies showed that thermocurrents generate a magnetic field in a horizontal cavity test assembly or cryomodul, which may get trapped during the supercon-ducting phase transition. The trapped flux causes additional dissipation in the order of 1 to 10 n' during operation and can therefore significantly degrade the quality factor in a TESLA cavity. We simulated the distribution of the generated magnetic field over the whole cavity-tank system for an asymmetric temperature distribution. The asymmetry allows the field to penetrate the RF surface which would be field free in the symmetric case. The calculated results complemented a direct measurement of trapped magnetic flux inside the cavity with a small number of field probes. Finally, the obtained data was combined with RF measurements in three passband modes to determine the overall distribution of trapped magnetic flux due to thermocurrents.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA048

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPVA050

Setup of a Spatially Resolving Vector Magnetometry System for the Investigation of Flux Trapping in Superconducting Cavities

975

SUSPSIK099

use link to see paper's listing under its alternate paper code

B. Schmitz, K.Alomari. Alomari, J. Knobloch, O. Kugeler, J.M. Köszegi, Y. Tamashevich
HZB, Berlin, Germany

Flux trapping is the major contribution to the residual resistance of superconducting cavities. In order to gain a better understanding of the mechanisms involved and aiming at an eventual minimization of trapped flux, a measurement setup based on AMR sensors was devised that allows for monitoring the magnetic field vector at various positions near the cavity surface. First results of the efforts are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA050

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)