SRF2015 - List of Authors (Tutte, A.R.J.)

Paper	Title	Page
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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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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Paper

Title

Page

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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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)