SRF2017 - List of Keywords (interface)

Paper	Title	Other Keywords	Page
MOPB019	Interface Challenges for the SRF Cryomodules for the European Spallation Source	ion, cryomodule, cavity, ion-source	100
	F. Schlander, C. Darve, N. Elias, C.G. Maiano ESS, Lund, Sweden P. Bosland CEA/DSM/IRFU, France G. Olry IPN, Orsay, France
	The European Spallation Source is currently under construction in Lund in southern Sweden. The main part of the accelerator will consist of two different types of cryomodules housing three different types of cavities ' double spoke cavities and two different elliptical cavities. The spoke cavities as well as the cryomodules will be provided by IPN Orsay, thus the external interfaces to the other accelerator systems have to be verified. While the procurement and assembly of the elliptical cryomodules will be performed by CEA Saclay, the cavities will be provided by INFN Milano and STFC Daresbury. Thus in addition to the external cryomodule interfaces, also the internal interfaces between cavities and cryomodules have to be taken care of. This contribution presents the challenges related to this work.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB019
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MOPB020	An Optimal Procedure for Coupler Conditioning for ESS Superconducting Linac	ion, cavity, vacuum, controls	103
	H. Li Uppsala University, Uppsala, Sweden E. Asensi Conejero, C.G. Maiano, R. Zeng ESS, Lund, Sweden
	An optimal procedure for coupler and cavity conditioning is proposed for the ESS superconducting cavities, which is applicable for different test stands and following installation in the ESS tunnel. A preliminary procedure has been developed and successfully tested at FREIA facility, Uppsala. The preliminary procedure will now be improved by integrating it into LLRF and EPICS control. This will be a joint effort between FREIA and ESS and will be used at the test stands in Lund and on the couplers installed in the tunnel. Developing the conditioning procedures on a common platform offers ESS significant advantages by allowing the procedures to be reused at different sites and by recording data in a consistent format. The details of the procedure, its development and testing will be reported and the future activities will be described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB020
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MOPB104	Development of a Novel Supporting System for High Luminosity LHC SRF Crab Cavities	ion, cavity, cryomodule, SRF	304
	T.J. Jones STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom K. Artoos, R. Calaga, O. Capatina, T. Capelli, M. Sosin, J.S. Swieszek, C. Zanoni CERN, Geneva, Switzerland G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom T.J. Jones Lancaster University, Lancaster, United Kingdom
	Compact SRF Crab Cavities are integral to the HL-LHC upgrade. This paper details the design of support structures within the SPS (Super Proton Synchrotron) Crab Cavity Cryomodule. For ease of alignment each cavity is supported with the mechanical tuner and RF Fundamental Power Coupler (FPC) via a common support plate. To reduce heat leak and remove bellows in the FPC it was determined that this would be the fixed support for the cavity (V. Parma, 2013). In addition, novel flexural blades were designed to give increased stiffness yet allow for thermal contraction of the cavity towards the fixed point of the FPC. This approach was superior when compared via simulation to several alternative techniques. A detailed simulation model was used for optimisation of directional stiffness, identification of vibration modes and minimising thermal stresses. A transmission matrix was developed in MS Excel to assess modal deflection for given ground vibration conditions. The spreadsheet gives an instantaneous yet comparable result to time consuming random vibration FE Analyses. The final engineering design of the supporting system is now complete and will also be described in this paper. References V. Parma, R. B. (2013). Status of the Superconducting Proton Linac (SPL) Cryomodule. SRF2013.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB104
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TUYBA02	Thermal Boundary Resistance Model and Defect Statistical Distribution in Nb/Cu Cavities	ion, cavity, ISOL, feedback	374
	R. Vaglio UniNa, Napoli, Italy V. Palmieri INFN/LNL, Legnaro (PD), Italy
	The ‘Q-slope' problem strongly limits the application of niobium thin film sputtered cavities in high field accelerators. Here we consider the hypothesis that the Q-slope is related to local enhanced of the thermal boundary resistance at the Nb/Cu interface, due to poor thermal contact between film and substrate. We introduce a simple model that directly connects the Q versus Eacc curves to the distribution function f(RNb/Cu) of RNb/Cu thermal contact at the Nb/Cu interface over the cavity surface. Starting from the experimental curves, using inverse problem methods, we deduce the distribution functions generating those curves. The technique has been applied to cavities by different groups, including LNL/INFN and ISOLDE/CERN. In all cases to explain the data it is sufficient to assume that only a small fraction of the film over the cavity surface is in poor thermal contact with the substrate. The distribution functions typically follow a simple power-law statistical distribution and are temperature independent. The full analysis supports the hypothesis that the main origin of the Q-slope in thin film cavities is indeed related to bad adhesion at the Nb/Cu interface.
	Slides TUYBA02 [0.988 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUYBA02
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TUYBA03	The Way of Thick Films toward a Flat Q-curve in Sputtered Cavities	ion, cavity, niobium, site	378
	V. Palmieri INFN/LNL, Legnaro (PD), Italy
	Thick films have bulk like properties. In this paper it is explored the possibility to sputter 70 micron thick films in order to get rid of the Q-slope in Niobium sputtered Cop-per Cavities. An innovative method based on the multi-layer deposition of zero-stress single layers is reported. The deposition of zero-stress thick films into 6 GHz Cop-per seamless cavities, has shown the possibility to obtain straight curves for the Q-factor versus accelerating fields Work supported by the INFN V group experiment ISIDE and performed under the CERN-INFN-FTSC Agreement N. KE2722/BE/FCC
	Slides TUYBA03 [4.935 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUYBA03
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THPB036	Fundamental SIMS Analyses for Nitrogen-enriched Niobium	ion, niobium, cavity, instrumentation	821
	J. Tuggle, M.J. Kelley Virginia Polytechnic Institute and State University, Blacksburg, USA M.J. Kelley, U. Pudasaini The College of William and Mary, Williamsburg, Virginia, USA M.J. Kelley, A.D. Palczewski, C.E. Reece JLab, Newport News, Virginia, USA F.A. Stevie NCSU AIF, Raleigh, North Carolina, USA
	Funding: Co-Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. W&M and VT work supported by the Office of High Energy Physics, U.S. DOE under grant DE-SC-0014475 In order to fully understand nitrogen addition techniques it is vital to have a full understanding of the material, including the content, location, and speciation of nitrogen contained in the treated Nb. In this work Secondary Ion Mass Spectrometry (SIMS) is used to elucidate content and location. Dynamic SIMS nitrogen analysis is reported, for the first time, for "as-received" cavity grade niobium from three separate suppliers. In addition, a number of method and instrumental issues are discussed including depth resolution, detection limit, and quantification.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THPB036
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOPB019

Interface Challenges for the SRF Cryomodules for the European Spallation Source

ion, cryomodule, cavity, ion-source

100

F. Schlander, C. Darve, N. Elias, C.G. Maiano
ESS, Lund, Sweden
P. Bosland
CEA/DSM/IRFU, France
G. Olry
IPN, Orsay, France

The European Spallation Source is currently under construction in Lund in southern Sweden. The main part of the accelerator will consist of two different types of cryomodules housing three different types of cavities ' double spoke cavities and two different elliptical cavities. The spoke cavities as well as the cryomodules will be provided by IPN Orsay, thus the external interfaces to the other accelerator systems have to be verified. While the procurement and assembly of the elliptical cryomodules will be performed by CEA Saclay, the cavities will be provided by INFN Milano and STFC Daresbury. Thus in addition to the external cryomodule interfaces, also the internal interfaces between cavities and cryomodules have to be taken care of. This contribution presents the challenges related to this work.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB019

Export •

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

MOPB020

An Optimal Procedure for Coupler Conditioning for ESS Superconducting Linac

ion, cavity, vacuum, controls

103

H. Li
Uppsala University, Uppsala, Sweden
E. Asensi Conejero, C.G. Maiano, R. Zeng
ESS, Lund, Sweden

An optimal procedure for coupler and cavity conditioning is proposed for the ESS superconducting cavities, which is applicable for different test stands and following installation in the ESS tunnel. A preliminary procedure has been developed and successfully tested at FREIA facility, Uppsala. The preliminary procedure will now be improved by integrating it into LLRF and EPICS control. This will be a joint effort between FREIA and ESS and will be used at the test stands in Lund and on the couplers installed in the tunnel. Developing the conditioning procedures on a common platform offers ESS significant advantages by allowing the procedures to be reused at different sites and by recording data in a consistent format. The details of the procedure, its development and testing will be reported and the future activities will be described.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB020

Export •

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

MOPB104

Development of a Novel Supporting System for High Luminosity LHC SRF Crab Cavities

ion, cavity, cryomodule, SRF

304

T.J. Jones
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
K. Artoos, R. Calaga, O. Capatina, T. Capelli, M. Sosin, J.S. Swieszek, C. Zanoni
CERN, Geneva, Switzerland
G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
T.J. Jones
Lancaster University, Lancaster, United Kingdom

Compact SRF Crab Cavities are integral to the HL-LHC upgrade. This paper details the design of support structures within the SPS (Super Proton Synchrotron) Crab Cavity Cryomodule. For ease of alignment each cavity is supported with the mechanical tuner and RF Fundamental Power Coupler (FPC) via a common support plate. To reduce heat leak and remove bellows in the FPC it was determined that this would be the fixed support for the cavity (V. Parma, 2013). In addition, novel flexural blades were designed to give increased stiffness yet allow for thermal contraction of the cavity towards the fixed point of the FPC. This approach was superior when compared via simulation to several alternative techniques. A detailed simulation model was used for optimisation of directional stiffness, identification of vibration modes and minimising thermal stresses. A transmission matrix was developed in MS Excel to assess modal deflection for given ground vibration conditions. The spreadsheet gives an instantaneous yet comparable result to time consuming random vibration FE Analyses. The final engineering design of the supporting system is now complete and will also be described in this paper.
References
V. Parma, R. B. (2013). Status of the Superconducting Proton Linac (SPL) Cryomodule. SRF2013.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-MOPB104

Export •

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

TUYBA02

Thermal Boundary Resistance Model and Defect Statistical Distribution in Nb/Cu Cavities

ion, cavity, ISOL, feedback

374

R. Vaglio
UniNa, Napoli, Italy
V. Palmieri
INFN/LNL, Legnaro (PD), Italy

The ‘Q-slope' problem strongly limits the application of niobium thin film sputtered cavities in high field accelerators. Here we consider the hypothesis that the Q-slope is related to local enhanced of the thermal boundary resistance at the Nb/Cu interface, due to poor thermal contact between film and substrate. We introduce a simple model that directly connects the Q versus Eacc curves to the distribution function f(RNb/Cu) of RNb/Cu thermal contact at the Nb/Cu interface over the cavity surface. Starting from the experimental curves, using inverse problem methods, we deduce the distribution functions generating those curves. The technique has been applied to cavities by different groups, including LNL/INFN and ISOLDE/CERN. In all cases to explain the data it is sufficient to assume that only a small fraction of the film over the cavity surface is in poor thermal contact with the substrate. The distribution functions typically follow a simple power-law statistical distribution and are temperature independent. The full analysis supports the hypothesis that the main origin of the Q-slope in thin film cavities is indeed related to bad adhesion at the Nb/Cu interface.

Slides TUYBA02 [0.988 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUYBA02

Export •

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

TUYBA03

The Way of Thick Films toward a Flat Q-curve in Sputtered Cavities

ion, cavity, niobium, site

378

V. Palmieri
INFN/LNL, Legnaro (PD), Italy

Thick films have bulk like properties. In this paper it is explored the possibility to sputter 70 micron thick films in order to get rid of the Q-slope in Niobium sputtered Cop-per Cavities. An innovative method based on the multi-layer deposition of zero-stress single layers is reported. The deposition of zero-stress thick films into 6 GHz Cop-per seamless cavities, has shown the possibility to obtain straight curves for the Q-factor versus accelerating fields
Work supported by the INFN V group experiment ISIDE and performed under the CERN-INFN-FTSC Agreement N. KE2722/BE/FCC

Slides TUYBA03 [4.935 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUYBA03

Export •

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

THPB036

Fundamental SIMS Analyses for Nitrogen-enriched Niobium

ion, niobium, cavity, instrumentation

821

J. Tuggle, M.J. Kelley
Virginia Polytechnic Institute and State University, Blacksburg, USA
M.J. Kelley, U. Pudasaini
The College of William and Mary, Williamsburg, Virginia, USA
M.J. Kelley, A.D. Palczewski, C.E. Reece
JLab, Newport News, Virginia, USA
F.A. Stevie
NCSU AIF, Raleigh, North Carolina, USA

Funding: Co-Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. W&M and VT work supported by the Office of High Energy Physics, U.S. DOE under grant DE-SC-0014475
In order to fully understand nitrogen addition techniques it is vital to have a full understanding of the material, including the content, location, and speciation of nitrogen contained in the treated Nb. In this work Secondary Ion Mass Spectrometry (SIMS) is used to elucidate content and location. Dynamic SIMS nitrogen analysis is reported, for the first time, for "as-received" cavity grade niobium from three separate suppliers. In addition, a number of method and instrumental issues are discussed including depth resolution, detection limit, and quantification.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THPB036

Export •

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