SRF2015 - List of Authors (De Silva, S.U.)

Paper	Title	Page
MOPB003	Superconducting Cavity for the Measurements of Frequency, Temperature, RF Field Dependence of the Surface Resistance	70
	H. Park, S.U. De Silva, J.R. Delayen ODU, Norfolk, Virginia, USA H. Park JLab, Newport News, Virginia, USA
	In order to better understand the contributions of the various physical processes to the surface resistance of superconductors the ODU Center for Accelerator Science is developing a half-wave resonator capable of operating between 325 MHz and 1.3 GHz. This will allow the measurement of the temperature and rf field dependence of the surface resistance on the same surface over the range of frequency of interest for particle accelerators and identify the various sources of power dissipation.
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THPB050	Performance Evaluation of HL-LHC Crab Cavity Prototypes in a CERN Vertical Test Cryostat	1210
	K.G. Hernández-Chahín DCI-UG, León, Mexico G. Burt Cockcroft Institute, Warrington, Cheshire, United Kingdom C. Christophe, A. Macpherson, M. Navarro-Tapia, R. Torres-Sanchez CERN, Geneva, Switzerland S.U. De Silva ODU, Norfolk, Virginia, USA A.R.J. Tutte Cockcroft Institute, Lancaster University, Lancaster, United Kingdom S. Verdú-Andrés BNL, Upton, Long Island, New York, USA
	Funding: My work is supported by the Mexican CONACYT(Consejo Nacional de Ciencia y Tecnologia) program through the Mexican national scholarship (Becas Nacionales y Becas Mixtas). Three proof-of-principle compact crab cavity designs have been fabricated in bulk niobium and cold tested at their home labs, as a first validation step towards the High Luminosity LHC project. As a cross check, all three bare cavities have been retested at CERN, in order to cross check their performance, and cross-calibrate the CERN SRF cold test facilities. While achievable transverse deflecting voltage is the key performance indicator, secondary performance aspects derived from multiple cavity monitoring systems are also discussed. Temperature mapping profiles, quench detection, material properties, and trapped magnetic flux effects have been assessed, and the influence on performance discussed. The significant effort invested in developing expertise in preparation and testing of these crab cavities has already been fruitful for all partners, and more is to come within this ongoing program.
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THPB053	Electromagnetic Design of 400 MHz RF-Dipole Crabbing Cavity for LHC High Luminosity Upgrade	1222
	S.U. De Silva, J.R. Delayen, H. Park ODU, Norfolk, Virginia, USA Z. Li SLAC, Menlo Park, California, USA
	The beam crabbing proposed for the LHC High Luminosity Upgrade requires two crabbing systems operating in both horizontal and vertical planes. In addition, the crabbing cavity design needs to meet strict dimensional constraints and functional specifications of the cavities. This paper presents the detailed electromagnetic design including em properties, multipole analysis, multipacting levels of the 400 MHz rf-dipole crabbing cavity.
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THPB069	Engineering Design and Prototype Fabrication of HOM Couplers for HL-LHC Crab Cavities	1279
	C. Zanoni, S. Atieh, I. Aviles Santillana, R. Calaga, O. Capatina, T. Capelli, F. Carra, P. Freijedo Menendez, M. Garlaschè, J.-M. Geisser, R. Leuxe, L. Marques Antunes Ferreira, E. Rigutto CERN, Geneva, Switzerland S.A. Belomestnykh, S. Verdú-Andrés, Q. Wu, B. P. Xiao BNL, Upton, Long Island, New York, USA G. Burt Lancaster University, Lancaster, United Kingdom S.U. De Silva, J.R. Delayen, R.G. Olave, H. Park ODU, Norfolk, Virginia, USA T.J. Jones, N. Templeton STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom Z. Li SLAC, Menlo Park, California, USA A.J. May, S.M. Pattalwar STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom T.H. Nicol Fermilab, Batavia, Illinois, USA A. Ratti LBNL, Berkeley, California, USA
	The High-Luminosity upgrade for the LHC relies on a set of RF Crab Cavities for reaching its goals. Two parallel concepts, the Double Quarter Wave (DQW) and the RF Dipole (RFD), are going through a comprehensive design process along with preparation of fabrication in view of extensive tests with beam in SPS. High Order Modes (HOM) couplers are critical in providing damping in RF cavities for operation in accelerators. HOM prototyping and fabrication have recently started at CERN. In this paper, an overview of the final shape is provided along with an insight in the mechanical and thermal analyses performed to validate the design of these critical components. Emphasis is also given to test campaigns, material selection, prototyping and initial fabrication that are aimed at fulfilling the highly demanding tolerances of the couplers.
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THPB070	Design of Dressed Crab Cavities for the HL-LHC Upgrade	1284
	C. Zanoni, K. Artoos, S. Atieh, I. Aviles Santillana, J.P. Brachet, R. Calaga, O. Capatina, T. Capelli, F. Carra, L. Dassa, G. Favre, P. Freijedo Menendez, M. Garlaschè, M. Guinchard, N. Kuder, S.A.E. Langeslag, R. Leuxe, L. Prever-Loiri, G. Vandoni CERN, Geneva, Switzerland S.A. Belomestnykh, I. Ben-Zvi, S. Verdú-Andrés, Q. Wu, B. P. Xiao BNL, Upton, Long Island, New York, USA I. Ben-Zvi Stony Brook University, Stony Brook, USA G. Burt Lancaster University, Lancaster, United Kingdom S.U. De Silva, R.G. Olave, H. Park ODU, Norfolk, Virginia, USA J.R. Delayen JLab, Newport News, Virginia, USA T.J. Jones, N. Templeton STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom Z. Li SLAC, Menlo Park, California, USA K.B. Marinov, A.J. May, S.M. Pattalwar STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom T.H. Nicol Fermilab, Batavia, Illinois, USA A. Ratti LBNL, Berkeley, California, USA
	The HL-LHC upgrade relies on a set of RF crab cavities for reaching its goals. Two parallel concepts, the Double Quarter Wave (DQW) and the RF Dipole (RFD), are going through a comprehensive design process along with preparation of fabrication in view of extensive tests with beam in SPS. High Order Modes (HOM) couplers are critical in providing damping in RF cavities for operation in accelerators. HOM prototyping and fabrication have recently started at CERN. In this paper, an overview of the final geometry is provided along with an insight in the mechanical and thermal analyses performed to validate the design of this critical component. Emphasis is also given to material selection, prototyping, initial fabrication and test campaigns that are aimed at fulfilling the highly demanding tolerances of the couplers.
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THPB081	FPC and HOM Coupler Test Boxes for HL-LHC Crab Cavities	1321
	A.R.J. Tutte, G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom R. Calaga, A. Macpherson, E. Montesinos CERN, Geneva, Switzerland S.U. De Silva ODU, Norfolk, Virginia, USA Z. Li SLAC, Menlo Park, California, USA B. P. Xiao BNL, Upton, Long Island, New York, USA
	The LHC luminosity upgrade will involve the installation of thirty-two 400 MHz SRF crab cavities. The cavities have two variants known as the RF dipole and double quarter-wave crab cavities. Each cavity has a fundamental power coupler (FPC) at 400 MHz and two or three HOM couplers. Before integration onto the cavities it is necessary to condition the FPC, and to measure the transmission on the HOM couplers at low power to ensure the operate as designed, each requiring a special test box. The FPC test box should provide a high transmission between two couplers without creating high surface fields. The low power HOM test boxes should be terminated to a load such that the natural stop and pass-bands of the couplers are preserved allowing the reflection to me measured and compared to simulations. In addition, due to the possibility of high HOM power in the LHC crab cavities, the concept of creating a broadband high power HOM coupler test box in order to condition and test the couplers at high power has been investigated. The Rf design of all test boxes is presented and discussed.
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FRBA02	Crab Cavity and Cryomodule Development for HL-LHC	1460
	F. Carra, A. Amorim Carvalho, K. Artoos, S. Atieh, I. Aviles Santillana, A.B. Boucherie, J.P. Brachet, K. Brodzinski, R. Calaga, O. Capatina, T. Capelli, L. Dassa, T. Dijoud, H.M. Durand, G. Favre, L.M.A. Ferreira, P. Freijedo Menendez, M. Garlaschè, M. Guinchard, N. Kuder, S.A.E. Langeslag, R. Leuxe, A. Macpherson, P. Minginette, E. Montesinos, F. Motschmann, C. Parente, L. Prever-Loiri, D. Pugnat, E. Rigutto, V. Rude, M. Sosin, G. Vandoni, G. Villiger, C. Zanoni CERN, Geneva, Switzerland S.A. Belomestnykh, S. Verdú-Andrés, Q. Wu, B. P. Xiao BNL, Upton, Long Island, New York, USA G. Burt Lancaster University, Lancaster, United Kingdom S.U. De Silva, J.R. Delayen, R.G. Olave, R.G. Olave, H. Park ODU, Norfolk, Virginia, USA T.J. Jones, N. Templeton STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom Z. Li SLAC, Menlo Park, California, USA K.B. Marinov, S.M. Pattalwar STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom T.H. Nicol Fermilab, Batavia, Illinois, USA A. Ratti LBNL, Berkeley, California, USA
	The HL-LHC project aims at increasing the LHC luminosity by a factor 10 beyond the design value. The installation of a set of RF Crab Cavities to increase bunch crossing angle is one of the key upgrades of the program. Two concepts, Double Quarter Wave (DQW) and RF Dipole (RFD) have been proposed and are being produced in parallel for test in the SPS beam before the next long shutdown of CERN accelerator’s complex. In the retained concept, two cavities are hosted in one single cryomodule, providing thermal insulation and interfacing with RF coupling, tuning, cryogenics and beam vacuum. This paper overviews the main design choices for the cryomodule and its different components, which have the goal of optimizing the structural, thermal and electro-magnetic behavior of the system, while respecting the existing constraints in terms of integration in the accelerator environment. Prototyping and testing of the most critical components, manufacturing, preparation and installation strategies are also described.
	Slides FRBA02 [4.678 MB]
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Paper

Title

Page

Superconducting Cavity for the Measurements of Frequency, Temperature, RF Field Dependence of the Surface Resistance

70

H. Park, S.U. De Silva, J.R. Delayen
ODU, Norfolk, Virginia, USA
H. Park
JLab, Newport News, Virginia, USA

In order to better understand the contributions of the various physical processes to the surface resistance of superconductors the ODU Center for Accelerator Science is developing a half-wave resonator capable of operating between 325 MHz and 1.3 GHz. This will allow the measurement of the temperature and rf field dependence of the surface resistance on the same surface over the range of frequency of interest for particle accelerators and identify the various sources of power dissipation.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

THPB050

Performance Evaluation of HL-LHC Crab Cavity Prototypes in a CERN Vertical Test Cryostat

1210

K.G. Hernández-Chahín
DCI-UG, León, Mexico
G. Burt
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C. Christophe, A. Macpherson, M. Navarro-Tapia, R. Torres-Sanchez
CERN, Geneva, Switzerland
S.U. De Silva
ODU, Norfolk, Virginia, USA
A.R.J. Tutte
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
S. Verdú-Andrés
BNL, Upton, Long Island, New York, USA

Funding: My work is supported by the Mexican CONACYT(Consejo Nacional de Ciencia y Tecnologia) program through the Mexican national scholarship (Becas Nacionales y Becas Mixtas).
Three proof-of-principle compact crab cavity designs have been fabricated in bulk niobium and cold tested at their home labs, as a first validation step towards the High Luminosity LHC project. As a cross check, all three bare cavities have been retested at CERN, in order to cross check their performance, and cross-calibrate the CERN SRF cold test facilities. While achievable transverse deflecting voltage is the key performance indicator, secondary performance aspects derived from multiple cavity monitoring systems are also discussed. Temperature mapping profiles, quench detection, material properties, and trapped magnetic flux effects have been assessed, and the influence on performance discussed. The significant effort invested in developing expertise in preparation and testing of these crab cavities has already been fruitful for all partners, and more is to come within this ongoing program.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

THPB053

Electromagnetic Design of 400 MHz RF-Dipole Crabbing Cavity for LHC High Luminosity Upgrade

1222

S.U. De Silva, J.R. Delayen, H. Park
ODU, Norfolk, Virginia, USA
Z. Li
SLAC, Menlo Park, California, USA

The beam crabbing proposed for the LHC High Luminosity Upgrade requires two crabbing systems operating in both horizontal and vertical planes. In addition, the crabbing cavity design needs to meet strict dimensional constraints and functional specifications of the cavities. This paper presents the detailed electromagnetic design including em properties, multipole analysis, multipacting levels of the 400 MHz rf-dipole crabbing cavity.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

THPB069

Engineering Design and Prototype Fabrication of HOM Couplers for HL-LHC Crab Cavities

1279

C. Zanoni, S. Atieh, I. Aviles Santillana, R. Calaga, O. Capatina, T. Capelli, F. Carra, P. Freijedo Menendez, M. Garlaschè, J.-M. Geisser, R. Leuxe, L. Marques Antunes Ferreira, E. Rigutto
CERN, Geneva, Switzerland
S.A. Belomestnykh, S. Verdú-Andrés, Q. Wu, B. P. Xiao
BNL, Upton, Long Island, New York, USA
G. Burt
Lancaster University, Lancaster, United Kingdom
S.U. De Silva, J.R. Delayen, R.G. Olave, H. Park
ODU, Norfolk, Virginia, USA
T.J. Jones, N. Templeton
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
Z. Li
SLAC, Menlo Park, California, USA
A.J. May, S.M. Pattalwar
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
T.H. Nicol
Fermilab, Batavia, Illinois, USA
A. Ratti
LBNL, Berkeley, California, USA

The High-Luminosity upgrade for the LHC relies on a set of RF Crab Cavities for reaching its goals. Two parallel concepts, the Double Quarter Wave (DQW) and the RF Dipole (RFD), are going through a comprehensive design process along with preparation of fabrication in view of extensive tests with beam in SPS. High Order Modes (HOM) couplers are critical in providing damping in RF cavities for operation in accelerators. HOM prototyping and fabrication have recently started at CERN. In this paper, an overview of the final shape is provided along with an insight in the mechanical and thermal analyses performed to validate the design of these critical components. Emphasis is also given to test campaigns, material selection, prototyping and initial fabrication that are aimed at fulfilling the highly demanding tolerances of the couplers.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

THPB070

Design of Dressed Crab Cavities for the HL-LHC Upgrade

1284

C. Zanoni, K. Artoos, S. Atieh, I. Aviles Santillana, J.P. Brachet, R. Calaga, O. Capatina, T. Capelli, F. Carra, L. Dassa, G. Favre, P. Freijedo Menendez, M. Garlaschè, M. Guinchard, N. Kuder, S.A.E. Langeslag, R. Leuxe, L. Prever-Loiri, G. Vandoni
CERN, Geneva, Switzerland
S.A. Belomestnykh, I. Ben-Zvi, S. Verdú-Andrés, Q. Wu, B. P. Xiao
BNL, Upton, Long Island, New York, USA
I. Ben-Zvi
Stony Brook University, Stony Brook, USA
G. Burt
Lancaster University, Lancaster, United Kingdom
S.U. De Silva, R.G. Olave, H. Park
ODU, Norfolk, Virginia, USA
J.R. Delayen
JLab, Newport News, Virginia, USA
T.J. Jones, N. Templeton
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
Z. Li
SLAC, Menlo Park, California, USA
K.B. Marinov, A.J. May, S.M. Pattalwar
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
T.H. Nicol
Fermilab, Batavia, Illinois, USA
A. Ratti
LBNL, Berkeley, California, USA

The HL-LHC upgrade relies on a set of RF crab cavities for reaching its goals. Two parallel concepts, the Double Quarter Wave (DQW) and the RF Dipole (RFD), are going through a comprehensive design process along with preparation of fabrication in view of extensive tests with beam in SPS. High Order Modes (HOM) couplers are critical in providing damping in RF cavities for operation in accelerators. HOM prototyping and fabrication have recently started at CERN. In this paper, an overview of the final geometry is provided along with an insight in the mechanical and thermal analyses performed to validate the design of this critical component. Emphasis is also given to material selection, prototyping, initial fabrication and test campaigns that are aimed at fulfilling the highly demanding tolerances of the couplers.

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reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

THPB081

FPC and HOM Coupler Test Boxes for HL-LHC Crab Cavities

1321

A.R.J. Tutte, G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
R. Calaga, A. Macpherson, E. Montesinos
CERN, Geneva, Switzerland
S.U. De Silva
ODU, Norfolk, Virginia, USA
Z. Li
SLAC, Menlo Park, California, USA
B. P. Xiao
BNL, Upton, Long Island, New York, USA

The LHC luminosity upgrade will involve the installation of thirty-two 400 MHz SRF crab cavities. The cavities have two variants known as the RF dipole and double quarter-wave crab cavities. Each cavity has a fundamental power coupler (FPC) at 400 MHz and two or three HOM couplers. Before integration onto the cavities it is necessary to condition the FPC, and to measure the transmission on the HOM couplers at low power to ensure the operate as designed, each requiring a special test box. The FPC test box should provide a high transmission between two couplers without creating high surface fields. The low power HOM test boxes should be terminated to a load such that the natural stop and pass-bands of the couplers are preserved allowing the reflection to me measured and compared to simulations. In addition, due to the possibility of high HOM power in the LHC crab cavities, the concept of creating a broadband high power HOM coupler test box in order to condition and test the couplers at high power has been investigated. The Rf design of all test boxes is presented and discussed.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

FRBA02

Crab Cavity and Cryomodule Development for HL-LHC

1460

F. Carra, A. Amorim Carvalho, K. Artoos, S. Atieh, I. Aviles Santillana, A.B. Boucherie, J.P. Brachet, K. Brodzinski, R. Calaga, O. Capatina, T. Capelli, L. Dassa, T. Dijoud, H.M. Durand, G. Favre, L.M.A. Ferreira, P. Freijedo Menendez, M. Garlaschè, M. Guinchard, N. Kuder, S.A.E. Langeslag, R. Leuxe, A. Macpherson, P. Minginette, E. Montesinos, F. Motschmann, C. Parente, L. Prever-Loiri, D. Pugnat, E. Rigutto, V. Rude, M. Sosin, G. Vandoni, G. Villiger, C. Zanoni
CERN, Geneva, Switzerland
S.A. Belomestnykh, S. Verdú-Andrés, Q. Wu, B. P. Xiao
BNL, Upton, Long Island, New York, USA
G. Burt
Lancaster University, Lancaster, United Kingdom
S.U. De Silva, J.R. Delayen, R.G. Olave, R.G. Olave, H. Park
ODU, Norfolk, Virginia, USA
T.J. Jones, N. Templeton
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
Z. Li
SLAC, Menlo Park, California, USA
K.B. Marinov, S.M. Pattalwar
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
T.H. Nicol
Fermilab, Batavia, Illinois, USA
A. Ratti
LBNL, Berkeley, California, USA

The HL-LHC project aims at increasing the LHC luminosity by a factor 10 beyond the design value. The installation of a set of RF Crab Cavities to increase bunch crossing angle is one of the key upgrades of the program. Two concepts, Double Quarter Wave (DQW) and RF Dipole (RFD) have been proposed and are being produced in parallel for test in the SPS beam before the next long shutdown of CERN accelerator’s complex. In the retained concept, two cavities are hosted in one single cryomodule, providing thermal insulation and interfacing with RF coupling, tuning, cryogenics and beam vacuum. This paper overviews the main design choices for the cryomodule and its different components, which have the goal of optimizing the structural, thermal and electro-magnetic behavior of the system, while respecting the existing constraints in terms of integration in the accelerator environment. Prototyping and testing of the most critical components, manufacturing, preparation and installation strategies are also described.

Slides FRBA02 [4.678 MB]

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