SRF2019 - List of Authors (Capatina, O.)

Paper	Title	Page
MOP099	Design of Crab Cavity Cryomodule for HL-LHC	320
	T. Capelli, K. Artoos, A.B. Boucherie, K. Brodzinski, R. Calaga, S.J. Calvo, E. Cano-Pleite, O. Capatina, F. Carra, L. Dassa, F. Eriksson, M. Garlasché, A. Krawczyk, R. Leuxe, P. Minginette, E. Montesinos, B. Prochal, M. Sosin, M. Therasse CERN, Geneva, Switzerland T.J. Jones, N. Templeton STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom A. Krawczyk, B. Prochal IFJ-PAN, Kraków, Poland S.M. Pattalwar STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: Research supported by the HL-LHC project Crab cavities are a key element to achieve the HL-LHC performance goals. There are two types of cavities Double Quarter Wave (DQW) for vertical crabbing, and Radiofrequency Dipole (RFD) for horizontal crabbing. Cavities are hosted in a cryomodule to provide optimal conditions for their operation at 2K while minimizing the external thermal loads and stray magnetic fields. One crab cryomodule contains more than thirteen thousand components and the assembly procedure for the first DQW prototype was carefully planned and executed. It was installed in the SPS accelerator at CERN in 2018 and successfully tested with proton beams. A review has thus been performed right after completion of the assembly in order to gather all the experience acquired and improve accordingly the design of the next generation of crab cryomodules. A second cryomodule with two RFD cavities is currently under production. This paper presents the lessons learnt from the first assembly and their implementation to the design of the future crab cryomodules.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP099
About •	paper received ※ 21 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP081	Status of the HL-LHC Crab Cavity Tuner	646
	K. Artoos, L. Arnaudon, R. Calaga, E. Cano-Pleite, O. Capatina, T. Capelli, D.F. Cartaxo dos Santos, M. Garlasché, D.C. Glenat, A. Krawczyk, R. Leuxe, P. Minginette, J.S. Swieszek CERN, Geneva, Switzerland T.J. Jones STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom A. Krawczyk, B. Prochal IFJ-PAN, Kraków, Poland J.A. Mitchell Lancaster University, Lancaster, United Kingdom S. Verdú-Andrés BNL, Upton, New York, USA
	Funding: Research supported by the HL-LHC project The resonance frequency of the HL-LHC Double Quarter Wave (DQW) and Radio Frequency Dipole (RFD) crab cavities is set to the operating frequency of 400.79 MHz by deforming the cavities. For both types of cavities, the tuning principle foresees a symmetric mechanical deformation of parts of the cavities in vertical direction, with the tuner motor placed outside on top of the vacuum vessel. The tuner design was successfully tested on the DQW prototype cryomodule with two cavities in 2018 in the SPS at CERN. This paper describes the design of DQW and RFD crab tuners. The experience and results of assembly and cold testing is given together with some required improvements. Finally, the final series crab tuners preparation is reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP081
About •	paper received ※ 21 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP012	Assessment of the Mechanical Properties of Ultra-High Purity Niobium After Cold Work and Heat Treatment With the HL-LHC Crab Cavities as Benchmark	860
	A. Gallifa Terricabras, A. Amorim Carvalho, I. Aviles Santillana, S. Barrière, R. Calaga, E. Cano-Pleite, O. Capatina, M.D. Crouvizier, L. Dassa, M.S. Meyer, N. Valverde Alonso CERN, Geneva, Switzerland M. Benke, A.B. Palotas, G. Szabó, M. Szűcs University of Miskolc, Faculty of Materials Science and Engineering, Miskolc-Egyetemváros, Hungary A. Hlavács, G.J. Krallics, V. Mertinger, M. Sepsi University of Miskolc, Miskolc, Hungary
	The High Luminosity Large Hadron Collider (HL-LHC) is the upgrade of the world’s largest particle collider; it will allow the full exploitation of the LHC potential and its operation beyond 2025. An essential part of the HL-LHC project are the Crab Cavities, that are particle deflecting SRF cavities of non-axisymmetric shape made of bulk ultra-high purity Nb. Since the cavities are produced by complex metal sheet forming processes, followed by a heat treatment (HT) for H outgassing (650 °C, 24 h), there is uncertainty on their mechanical properties after manufacturing and in service conditions (2 K). Mechanical tests at room temperature have been conducted on RRR300 pure Nb samples. The samples were previously submitted, by cold cross-rolling, to different levels of plastic deformation representative of the effective plastic strain seen by the Nb sheets during forming operations. Moreover, a comparison of the mechanical properties of cold cross-rolled samples before and after HT has been established. Results of evolution of the microstructure and hardness are also presented. This study can be of interest for Nb cavities to be sub-mitted to HT at 650 °C, and may help to push the design of novel SRF cavities.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP012
About •	paper received ※ 22 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP036	An Insight on the Thermal and Mechanical Numerical Evaluations for the High-Luminosity LHC Crab Cavities	929
	E. Cano-Pleite, A. Amorim Carvalho, K. Artoos, R. Calaga, O. Capatina, T. Capelli, F. Carra, L. Dassa, M. Garlasché, R. Leuxe, E. Montesinos CERN, Meyrin, Switzerland J.A. Mitchell Lancaster University, Lancaster, United Kingdom S. Verdú-Andrés BNL, Upton, New York, USA
	Funding: Research supported by the HL-LHC project One of the key devices of the HL-LHC project are SRF crab cavities. A cryomodule with two Double Quarter Wave (DQW) crab cavities has been successfully fabricat-ed and tested with beam at CERN whereas the Radio Frequency Dipole (RFD) crab cavities are currently on its fabrication process. The paper provides an insight on the multiple calculations carried out to evaluate the thermal and mechanical performance of the DQW and RFD cavi-ties and its components. In some cases, the presence of RF fields inside the cavity volume requires the use of mul-tiphysics numerical models capable of coupling these fields with the thermal and mechanical domains. In fact, the RF field presents a strong dependency on the cavity shape, whereas the mechanical, thermal and electrical properties of the materials may substantially vary as a function of temperature, which in turn depends on the RF field. The results presented in this paper, using both cou-pled and uncoupled models, allowed elucidating the importance of physics coupling on the numerical evalua-tion of RF cavities and its components. Analyses were also of great support for the design evaluation and im-provement of future prototypes.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP036
About •	paper received ※ 21 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP106	An SRF Test Stand in High Intensity and High Energy Proton Beams	1187
	G. Vandoni, K. Artoos, V. Baglin, K. Brodzinski, R. Calaga, O. Capatina, S.D. Claudet, L.P. Delprat, S. Mehanneche, E. Montesinos, C. Pasquino, J.S. Swieszek CERN, Geneva, Switzerland
	In the framework of HL-LHC, a new infrastructure was installed in 2018, to test SRF structures in the proton beams of the SPS. Scope of the test stand is to study the operational performance of crab cavities for HL-LHC – more generally, SRF cavities – through a wide range of proton beam parameters up to high energy and current, under safe conditions for equipment and personnel. The SPS beam instrumentation is used to monitor orbit centering, RF phase scans, bunch rotation. To minimize impact on beam time, infrastructure and services allow for full remote control. Critical aperture restrictions is overcome by placing the test structure and its ancillaries on a motorized table for lateral translation in- and out of beam. Two articulated Y-shaped vacuum chambers connect the test cryomodule on a beam by-pass. A new cryogenic refrigerator is installed in a split scheme, with an underground cold box fed from a surface compressor. The two Inductive Output Tubes (IOT) power amplifiers deliver up to 60 kW cw via coaxial transmission lines to the two cavities and charges and circulators, the latter installed on the translation table. Interlocks and safety equipment complete the test stand.
	Poster THP106 [3.982 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP106
About •	paper received ※ 23 June 2019 paper accepted ※ 01 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Design of Crab Cavity Cryomodule for HL-LHC

320

T. Capelli, K. Artoos, A.B. Boucherie, K. Brodzinski, R. Calaga, S.J. Calvo, E. Cano-Pleite, O. Capatina, F. Carra, L. Dassa, F. Eriksson, M. Garlasché, A. Krawczyk, R. Leuxe, P. Minginette, E. Montesinos, B. Prochal, M. Sosin, M. Therasse
CERN, Geneva, Switzerland
T.J. Jones, N. Templeton
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
A. Krawczyk, B. Prochal
IFJ-PAN, Kraków, Poland
S.M. Pattalwar
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Funding: Research supported by the HL-LHC project
Crab cavities are a key element to achieve the HL-LHC performance goals. There are two types of cavities Double Quarter Wave (DQW) for vertical crabbing, and Radiofrequency Dipole (RFD) for horizontal crabbing. Cavities are hosted in a cryomodule to provide optimal conditions for their operation at 2K while minimizing the external thermal loads and stray magnetic fields. One crab cryomodule contains more than thirteen thousand components and the assembly procedure for the first DQW prototype was carefully planned and executed. It was installed in the SPS accelerator at CERN in 2018 and successfully tested with proton beams. A review has thus been performed right after completion of the assembly in order to gather all the experience acquired and improve accordingly the design of the next generation of crab cryomodules. A second cryomodule with two RFD cavities is currently under production. This paper presents the lessons learnt from the first assembly and their implementation to the design of the future crab cryomodules.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-MOP099

About •

paper received ※ 21 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

Export •

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

TUP081

Status of the HL-LHC Crab Cavity Tuner

646

K. Artoos, L. Arnaudon, R. Calaga, E. Cano-Pleite, O. Capatina, T. Capelli, D.F. Cartaxo dos Santos, M. Garlasché, D.C. Glenat, A. Krawczyk, R. Leuxe, P. Minginette, J.S. Swieszek
CERN, Geneva, Switzerland
T.J. Jones
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
A. Krawczyk, B. Prochal
IFJ-PAN, Kraków, Poland
J.A. Mitchell
Lancaster University, Lancaster, United Kingdom
S. Verdú-Andrés
BNL, Upton, New York, USA

Funding: Research supported by the HL-LHC project
The resonance frequency of the HL-LHC Double Quarter Wave (DQW) and Radio Frequency Dipole (RFD) crab cavities is set to the operating frequency of 400.79 MHz by deforming the cavities. For both types of cavities, the tuning principle foresees a symmetric mechanical deformation of parts of the cavities in vertical direction, with the tuner motor placed outside on top of the vacuum vessel. The tuner design was successfully tested on the DQW prototype cryomodule with two cavities in 2018 in the SPS at CERN. This paper describes the design of DQW and RFD crab tuners. The experience and results of assembly and cold testing is given together with some required improvements. Finally, the final series crab tuners preparation is reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP081

About •

paper received ※ 21 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

Export •

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

THP012

Assessment of the Mechanical Properties of Ultra-High Purity Niobium After Cold Work and Heat Treatment With the HL-LHC Crab Cavities as Benchmark

860

A. Gallifa Terricabras, A. Amorim Carvalho, I. Aviles Santillana, S. Barrière, R. Calaga, E. Cano-Pleite, O. Capatina, M.D. Crouvizier, L. Dassa, M.S. Meyer, N. Valverde Alonso
CERN, Geneva, Switzerland
M. Benke, A.B. Palotas, G. Szabó, M. Szűcs
University of Miskolc, Faculty of Materials Science and Engineering, Miskolc-Egyetemváros, Hungary
A. Hlavács, G.J. Krallics, V. Mertinger, M. Sepsi
University of Miskolc, Miskolc, Hungary

The High Luminosity Large Hadron Collider (HL-LHC) is the upgrade of the world’s largest particle collider; it will allow the full exploitation of the LHC potential and its operation beyond 2025. An essential part of the HL-LHC project are the Crab Cavities, that are particle deflecting SRF cavities of non-axisymmetric shape made of bulk ultra-high purity Nb. Since the cavities are produced by complex metal sheet forming processes, followed by a heat treatment (HT) for H outgassing (650 °C, 24 h), there is uncertainty on their mechanical properties after manufacturing and in service conditions (2 K). Mechanical tests at room temperature have been conducted on RRR300 pure Nb samples. The samples were previously submitted, by cold cross-rolling, to different levels of plastic deformation representative of the effective plastic strain seen by the Nb sheets during forming operations. Moreover, a comparison of the mechanical properties of cold cross-rolled samples before and after HT has been established. Results of evolution of the microstructure and hardness are also presented. This study can be of interest for Nb cavities to be sub-mitted to HT at 650 °C, and may help to push the design of novel SRF cavities.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP012

About •

paper received ※ 22 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

Export •

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

THP036

An Insight on the Thermal and Mechanical Numerical Evaluations for the High-Luminosity LHC Crab Cavities

929

E. Cano-Pleite, A. Amorim Carvalho, K. Artoos, R. Calaga, O. Capatina, T. Capelli, F. Carra, L. Dassa, M. Garlasché, R. Leuxe, E. Montesinos
CERN, Meyrin, Switzerland
J.A. Mitchell
Lancaster University, Lancaster, United Kingdom
S. Verdú-Andrés
BNL, Upton, New York, USA

Funding: Research supported by the HL-LHC project
One of the key devices of the HL-LHC project are SRF crab cavities. A cryomodule with two Double Quarter Wave (DQW) crab cavities has been successfully fabricat-ed and tested with beam at CERN whereas the Radio Frequency Dipole (RFD) crab cavities are currently on its fabrication process. The paper provides an insight on the multiple calculations carried out to evaluate the thermal and mechanical performance of the DQW and RFD cavi-ties and its components. In some cases, the presence of RF fields inside the cavity volume requires the use of mul-tiphysics numerical models capable of coupling these fields with the thermal and mechanical domains. In fact, the RF field presents a strong dependency on the cavity shape, whereas the mechanical, thermal and electrical properties of the materials may substantially vary as a function of temperature, which in turn depends on the RF field. The results presented in this paper, using both cou-pled and uncoupled models, allowed elucidating the importance of physics coupling on the numerical evalua-tion of RF cavities and its components. Analyses were also of great support for the design evaluation and im-provement of future prototypes.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP036

About •

paper received ※ 21 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

Export •

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

THP106

An SRF Test Stand in High Intensity and High Energy Proton Beams

1187

G. Vandoni, K. Artoos, V. Baglin, K. Brodzinski, R. Calaga, O. Capatina, S.D. Claudet, L.P. Delprat, S. Mehanneche, E. Montesinos, C. Pasquino, J.S. Swieszek
CERN, Geneva, Switzerland

In the framework of HL-LHC, a new infrastructure was installed in 2018, to test SRF structures in the proton beams of the SPS. Scope of the test stand is to study the operational performance of crab cavities for HL-LHC – more generally, SRF cavities – through a wide range of proton beam parameters up to high energy and current, under safe conditions for equipment and personnel. The SPS beam instrumentation is used to monitor orbit centering, RF phase scans, bunch rotation. To minimize impact on beam time, infrastructure and services allow for full remote control. Critical aperture restrictions is overcome by placing the test structure and its ancillaries on a motorized table for lateral translation in- and out of beam. Two articulated Y-shaped vacuum chambers connect the test cryomodule on a beam by-pass. A new cryogenic refrigerator is installed in a split scheme, with an underground cold box fed from a surface compressor. The two Inductive Output Tubes (IOT) power amplifiers deliver up to 60 kW cw via coaxial transmission lines to the two cavities and charges and circulators, the latter installed on the translation table. Interlocks and safety equipment complete the test stand.

Poster THP106 [3.982 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP106

About •

paper received ※ 23 June 2019 paper accepted ※ 01 July 2019 issue date ※ 14 August 2019

Export •

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