IPAC2019 - List of Authors (Alekou, A.)

Paper	Title	Page
MOPGW094	First Machine Developments Result with HL-LHC Crab Cavities in the SPS	338
	L.R. Carver, A. Alekou, F. Antoniou, H. Bartosik, T. Bohl, R. Calaga, M. Carlà, T.E. Levens, G. Papotti CERN, Geneva, Switzerland A. Alekou, R.B. Appleby, R.B. Appleby UMAN, Manchester, United Kingdom G. Burt Cockcroft Institute, Warrington, Cheshire, United Kingdom G. Burt, J.A. Mitchell Lancaster University, Lancaster, United Kingdom C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	Crab cavities are a critical component within the High Luminosity upgrade project for the Large Hadron Collider (HL-LHC). It is foreseen to use crab cavities in order to compensate the geometric luminosity reduction factor (reduction of the luminous region at the Interaction Point [IP]) due to the beam crossing angle (required for minimizing the impact of the long range beam-beam effects on the single particle beam dynamics) and increase the number of collisions per bunch crossing. In 2018 the first beam tests of crab cavities with protons were performed in the Super Proton Synchrotron (SPS) at CERN. Two vertical superconducting cavities of the Double Quarter Wave (DQW) type were fabricated and installed in the SPS to verify some key components of the cavity design and operation. This paper will present some of the first results relating to the proton beam dynamics in the presence of crab cavities.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW094
About •	paper received ※ 25 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPGW095	Beam Dynamics Simulations with Crab Cavities in the SPS Machine	342
	A. Alekou, A. Alekou, H. Bartosik, H. Bartosik, M. Carlà, Y. Papaphilippou, Y. Papaphilippou, Y. Papaphilippou CERN, Geneva, Switzerland A. Alekou, A. Alekou, R.B. Appleby, R.B. Appleby UMAN, Manchester, United Kingdom R.B. Appleby Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The LHC Upgrade, called High Luminosity LHC, aims to increase the integrated luminosity by a factor of 10. To achieve this, the project relies on a number of key innovative technologies, including the use of superconducting Crab Cavities with ultra-precise phase control for beam rotation. A set of prototype Crab Cavities has been recently installed in the second largest machine of CERN, the Super Proton Synchrotron (SPS), that operated as a test-bed from May to November of 2018. The tight LHC constraints call for axially non-symmetric cavity designs that introduce high order multipole components. Furthermore, the Crab Cavities in the presence of SPS non-linearities can affect the long term stability of the beam. This paper presents how the SPS dynamic aperture is affected for different cavity, machine and beam configurations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW095
About •	paper received ※ 06 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPTS090	Beam-Based Measurement of the Skew-Sextupolar Component of the Radio Frequency Field of a HL-LHC-Type Crab-Cavity	1066
	M. Carlà, A. Alekou, H. Bartosik, L.R. Carver CERN, Meyrin, Switzerland
	Two High Luminosity Large Hadron Collider (LHC) type crab-cavities have been installed in the CERN SPS for testing purposes. An attempt to characterize the skew-sextupolar component of the radio frequency field of the crab-cavity (a3) has been carried out by means of beam-based techniques using turn-by-turn monitoring of the betatron motion. The skew nature of a3 couples the horizontal and vertical betatron motions through a non-linear term. Therefore by exciting the horizontal betatron motion it was possible to observe a spectral line in the vertical beam motion driven by the non-linear coupling at the characteristic frequency 2Qx. A measurement of the magnitude of a3 was thus obtained by characterizing amplitude and phase of such line. The results of the measurements are discussed here.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS090
About •	paper received ※ 06 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

First Machine Developments Result with HL-LHC Crab Cavities in the SPS

338

L.R. Carver, A. Alekou, F. Antoniou, H. Bartosik, T. Bohl, R. Calaga, M. Carlà, T.E. Levens, G. Papotti
CERN, Geneva, Switzerland
A. Alekou, R.B. Appleby, R.B. Appleby
UMAN, Manchester, United Kingdom
G. Burt
Cockcroft Institute, Warrington, Cheshire, United Kingdom
G. Burt, J.A. Mitchell
Lancaster University, Lancaster, United Kingdom
C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Crab cavities are a critical component within the High Luminosity upgrade project for the Large Hadron Collider (HL-LHC). It is foreseen to use crab cavities in order to compensate the geometric luminosity reduction factor (reduction of the luminous region at the Interaction Point [IP]) due to the beam crossing angle (required for minimizing the impact of the long range beam-beam effects on the single particle beam dynamics) and increase the number of collisions per bunch crossing. In 2018 the first beam tests of crab cavities with protons were performed in the Super Proton Synchrotron (SPS) at CERN. Two vertical superconducting cavities of the Double Quarter Wave (DQW) type were fabricated and installed in the SPS to verify some key components of the cavity design and operation. This paper will present some of the first results relating to the proton beam dynamics in the presence of crab cavities.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW094

About •

paper received ※ 25 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

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

MOPGW095

Beam Dynamics Simulations with Crab Cavities in the SPS Machine

342

A. Alekou, A. Alekou, H. Bartosik, H. Bartosik, M. Carlà, Y. Papaphilippou, Y. Papaphilippou, Y. Papaphilippou
CERN, Geneva, Switzerland
A. Alekou, A. Alekou, R.B. Appleby, R.B. Appleby
UMAN, Manchester, United Kingdom
R.B. Appleby
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The LHC Upgrade, called High Luminosity LHC, aims to increase the integrated luminosity by a factor of 10. To achieve this, the project relies on a number of key innovative technologies, including the use of superconducting Crab Cavities with ultra-precise phase control for beam rotation. A set of prototype Crab Cavities has been recently installed in the second largest machine of CERN, the Super Proton Synchrotron (SPS), that operated as a test-bed from May to November of 2018. The tight LHC constraints call for axially non-symmetric cavity designs that introduce high order multipole components. Furthermore, the Crab Cavities in the presence of SPS non-linearities can affect the long term stability of the beam. This paper presents how the SPS dynamic aperture is affected for different cavity, machine and beam configurations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW095

About •

paper received ※ 06 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

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

MOPTS090

Beam-Based Measurement of the Skew-Sextupolar Component of the Radio Frequency Field of a HL-LHC-Type Crab-Cavity

1066

M. Carlà, A. Alekou, H. Bartosik, L.R. Carver
CERN, Meyrin, Switzerland

Two High Luminosity Large Hadron Collider (LHC) type crab-cavities have been installed in the CERN SPS for testing purposes. An attempt to characterize the skew-sextupolar component of the radio frequency field of the crab-cavity (a3) has been carried out by means of beam-based techniques using turn-by-turn monitoring of the betatron motion. The skew nature of a3 couples the horizontal and vertical betatron motions through a non-linear term. Therefore by exciting the horizontal betatron motion it was possible to observe a spectral line in the vertical beam motion driven by the non-linear coupling at the characteristic frequency 2Qx. A measurement of the magnitude of a3 was thus obtained by characterizing amplitude and phase of such line. The results of the measurements are discussed here.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS090

About •

paper received ※ 06 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

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