SRF2017 - List of Authors (Kaufman, J.J.)

Paper	Title	Page
TUPB073	Vertical Electro-polishing Collaboration Between Cornell, KEK, and Marui Galvanizing Co. Ltd	563
	F. Furuta, M. Ge, T. Gruber, J.J. Kaufman, M. Liepe, J. Sears Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA V. Chouhan, Y.I. Ida, K.N. Nii, T.Y. Yamaguchi MGH, Hyogo-ken, Japan H. Hayano, S. Kato, T. Saeki KEK, Ibaraki, Japan
	Cornell's SRF group, KEK, and Marui Galvanizing Co. Ltd (MGI) have collaborated since 2014 on Vertical Electro-Polishing (VEP) R&D as a part of a US/Japan Program for Cooperation in High Energy Physics. We have focused on an improvement of removal uniformity during the VEP process. MGI and KEK have developed their original VEP cathode named i-cathode Ninja®, which has four retractable wing-shape parts per cell. Cornell processed one single cell cavity with VEP using this cathode and performed a vertical test. KEK also provided one 9-cell cavity to Cornell. Cornell then performed surface treatments including Cornell VEP and RF test on this 9-cell cavity. The progress by the VEP collaboration and RF test results are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUPB073
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TUPB074	RF Performance of Multi-cell Scale Niobium SRF Cavities Prepared with HF Free Bipolar Electro-polishing at Faraday Technology	567
	F. Furuta, M. Ge, T. Gruber, J.J. Kaufman, M. Liepe, J. Sears Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA T.D. Hall, M.E. Inman, R. Radhakrishnan, S.T. Snyder, E.J. Taylor Faraday Technology, Inc., Clayton, Ohio, USA
	Cornell's SRF group and Faraday Technology, Inc. have been collaborating on two phase-II SBIR projects. One of them is the development and commissioning of a 9-cell scale HF free Bipolar Electro-Polishing (BEP) system. Faraday Technology had completed the proof of principle on BEP with single cell scale prior to the work reported here, and has now developed a new 9-cell scale BEP system. Cornell has fabricated three single cell cavities and has assembled them together as a 9-cell scale test string. The 9-cell scale test string has received BEP at Faraday Technology and RF testing has been performed on the three single cell cavities one-by-one at Cornell. Here we give a status update on the new 9-cell scale BEP system commissioning and on results from RF tests of the BEP cavities.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUPB074
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THPB004	Impact of the Duration of Low Temperature Doping on Superconducting Cavity Performance	750
	P.N. Koufalis, F. Furuta, J.J. Kaufman, M. Liepe Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Low temperature treatments of superconducting cavities in a low pressure ambient atmosphere have been shown to introduce a 'Q-rise' up to moderate surface fields and an overall increase in quality factor. However, the effect of varying the doping time at a fixed temperature on cavity performance has not been systematically examined. We present results of such an investigation for cavities prepared at 120 and 160 C in a continuously flowing low pressure atmosphere for various amounts of time. We show that the introduction of impurities to the RF penetration layer can improve cavity performance and investigate the relationship between electron mean free path and the temperature-dependent component of the surface resistance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THPB004
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Paper

Title

Page

Vertical Electro-polishing Collaboration Between Cornell, KEK, and Marui Galvanizing Co. Ltd

563

F. Furuta, M. Ge, T. Gruber, J.J. Kaufman, M. Liepe, J. Sears
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
V. Chouhan, Y.I. Ida, K.N. Nii, T.Y. Yamaguchi
MGH, Hyogo-ken, Japan
H. Hayano, S. Kato, T. Saeki
KEK, Ibaraki, Japan

Cornell's SRF group, KEK, and Marui Galvanizing Co. Ltd (MGI) have collaborated since 2014 on Vertical Electro-Polishing (VEP) R&D as a part of a US/Japan Program for Cooperation in High Energy Physics. We have focused on an improvement of removal uniformity during the VEP process. MGI and KEK have developed their original VEP cathode named i-cathode Ninja®, which has four retractable wing-shape parts per cell. Cornell processed one single cell cavity with VEP using this cathode and performed a vertical test. KEK also provided one 9-cell cavity to Cornell. Cornell then performed surface treatments including Cornell VEP and RF test on this 9-cell cavity. The progress by the VEP collaboration and RF test results are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUPB073

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TUPB074

RF Performance of Multi-cell Scale Niobium SRF Cavities Prepared with HF Free Bipolar Electro-polishing at Faraday Technology

567

F. Furuta, M. Ge, T. Gruber, J.J. Kaufman, M. Liepe, J. Sears
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
T.D. Hall, M.E. Inman, R. Radhakrishnan, S.T. Snyder, E.J. Taylor
Faraday Technology, Inc., Clayton, Ohio, USA

Cornell's SRF group and Faraday Technology, Inc. have been collaborating on two phase-II SBIR projects. One of them is the development and commissioning of a 9-cell scale HF free Bipolar Electro-Polishing (BEP) system. Faraday Technology had completed the proof of principle on BEP with single cell scale prior to the work reported here, and has now developed a new 9-cell scale BEP system. Cornell has fabricated three single cell cavities and has assembled them together as a 9-cell scale test string. The 9-cell scale test string has received BEP at Faraday Technology and RF testing has been performed on the three single cell cavities one-by-one at Cornell. Here we give a status update on the new 9-cell scale BEP system commissioning and on results from RF tests of the BEP cavities.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUPB074

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

THPB004

Impact of the Duration of Low Temperature Doping on Superconducting Cavity Performance

750

P.N. Koufalis, F. Furuta, J.J. Kaufman, M. Liepe
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Low temperature treatments of superconducting cavities in a low pressure ambient atmosphere have been shown to introduce a 'Q-rise' up to moderate surface fields and an overall increase in quality factor. However, the effect of varying the doping time at a fixed temperature on cavity performance has not been systematically examined. We present results of such an investigation for cavities prepared at 120 and 160 C in a continuously flowing low pressure atmosphere for various amounts of time. We show that the introduction of impurities to the RF penetration layer can improve cavity performance and investigate the relationship between electron mean free path and the temperature-dependent component of the surface resistance.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THPB004

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