HB2018 - List of Keywords (luminosity)

Paper	Title	Other Keywords	Page
WEP2PO002	Scaling Laws for the Time Dependence of Luminosity in Hadron Circular Accelerators based on Simple Models of Dynamic Aperture Evolution	collider, proton, hadron, experiment	260
	F.F. Van der Veken, M. Giovannozzi CERN, Geneva, Switzerland
	In recent years, models for the time-evolution of the dynamic aperture have been proposed and applied to the analysis of non-linear betatronic motion in circular accelerators. In this paper, these models are used to derive scaling laws for the luminosity evolution and are applied to the analysis of the data collected during the LHC physics runs. An extended set of fills from the LHC proton physics has been analysed and the results presented and discussed in detail. The long-term goal of these studies is to improve the estimate of the performance reach of the HL-LHC.
	Poster WEP2PO002 [5.757 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-WEP2PO002
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WEP2PO008	SPS Long Term Stability Studies in the Presence of Crab Cavities and High Order Multipoles	multipole, cavity, optics, sextupole	284
	A. Alekou, H. Bartosik, R. Calaga, M. Carlà, Y. Papaphilippou CERN, Geneva, Switzerland R.B. Appleby, R.B. Appleby UMAN, Manchester, United Kingdom R.B. Appleby Cockcroft Institute, Warrington, Cheshire, United Kingdom
	A local Crab Cavity (CC) scheme will recover the head-on collisions at the IP of the High Luminosity LHC (HL-LHC), which aims to increase the LHC luminosity by a factor of 3-10. The tight space constraints at the CC location result in axially non-symmetric cavity designs that introduce high order multipole CC components. The impact of these high order components on the long term stability of the beam in the SPS machine, where two prototype crab cavities are presently installed in the CERN SPS to perform tests with beam, is presented. Furthermore, the Dynamic Aperture is studied in the presence of the SPS errors. Future plans are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-WEP2PO008
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THA2WD01	Operation Challenges and Performance of the LHC During Run II	emittance, MMI, operation, brightness	357
	R. Steerenberg, J. Wenninger CERN, Geneva, Switzerland
	The CERN Large Hadron Collider Run II saw an important increase in beam performance through both, improvements in the LHC and an increased beam brightness from the injectors, leading to a peak luminosity that exceeds the LHC design luminosity by more than a factor two. This contribution will give an overview of run 2, the main challenges encountered and it will address the measures applied to deal with and make use of the increased beam brightness. Finally potential areas where further performance improvement can be a realized will be identified.
	Slides THA2WD01 [6.709 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-THA2WD01
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP2WC02	LLRF Studies for HL-LHC Crab Cavities	cavity, feedback, emittance, betatron	440
	P. Baudrenghien CERN, Geneva, Switzerland T. Mastoridis CalPoly, San Luis Obispo, California, USA
	The HL-LHC upgrade includes sixteen Crab Cavities (CC) to be installed on both sides of the high luminosity experiments, ATLAS and CMS. Two issues have been highlighted for the Low Level RF: transverse emittance growth (and associated luminosity drop) caused by CC RF noise, and large collimator losses following a CC trip. A prototype cryomodule with two CCs has been installed in the SPS, and tests have started in May 2018 with beam. This paper briefly reports on preliminary results from the SPS tests. It then presents emittance growth calculations from cavity field phase and amplitude noise, deduces the maximum RF noise compatible with the specifications and presents a possible cure consisting of a feedback on CC phase and amplitude. To reduce the losses following a CC trip we propose to implement transverse tail cleaning via the injection of CC noise with an optimized spectrum, which selectively excites the particles of large transverse oscillation amplitudes.
	Slides THP2WC02 [1.943 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-THP2WC02
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

Scaling Laws for the Time Dependence of Luminosity in Hadron Circular Accelerators based on Simple Models of Dynamic Aperture Evolution

collider, proton, hadron, experiment

260

F.F. Van der Veken, M. Giovannozzi
CERN, Geneva, Switzerland

In recent years, models for the time-evolution of the dynamic aperture have been proposed and applied to the analysis of non-linear betatronic motion in circular accelerators. In this paper, these models are used to derive scaling laws for the luminosity evolution and are applied to the analysis of the data collected during the LHC physics runs. An extended set of fills from the LHC proton physics has been analysed and the results presented and discussed in detail. The long-term goal of these studies is to improve the estimate of the performance reach of the HL-LHC.

Poster WEP2PO002 [5.757 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-WEP2PO002

Export •

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

WEP2PO008

SPS Long Term Stability Studies in the Presence of Crab Cavities and High Order Multipoles

multipole, cavity, optics, sextupole

284

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

A local Crab Cavity (CC) scheme will recover the head-on collisions at the IP of the High Luminosity LHC (HL-LHC), which aims to increase the LHC luminosity by a factor of 3-10. The tight space constraints at the CC location result in axially non-symmetric cavity designs that introduce high order multipole CC components. The impact of these high order components on the long term stability of the beam in the SPS machine, where two prototype crab cavities are presently installed in the CERN SPS to perform tests with beam, is presented. Furthermore, the Dynamic Aperture is studied in the presence of the SPS errors. Future plans are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-WEP2PO008

Export •

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

THA2WD01

Operation Challenges and Performance of the LHC During Run II

emittance, MMI, operation, brightness

357

R. Steerenberg, J. Wenninger
CERN, Geneva, Switzerland

The CERN Large Hadron Collider Run II saw an important increase in beam performance through both, improvements in the LHC and an increased beam brightness from the injectors, leading to a peak luminosity that exceeds the LHC design luminosity by more than a factor two. This contribution will give an overview of run 2, the main challenges encountered and it will address the measures applied to deal with and make use of the increased beam brightness. Finally potential areas where further performance improvement can be a realized will be identified.

Slides THA2WD01 [6.709 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-THA2WD01

Export •

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

THP2WC02

LLRF Studies for HL-LHC Crab Cavities

cavity, feedback, emittance, betatron

440

P. Baudrenghien
CERN, Geneva, Switzerland
T. Mastoridis
CalPoly, San Luis Obispo, California, USA

The HL-LHC upgrade includes sixteen Crab Cavities (CC) to be installed on both sides of the high luminosity experiments, ATLAS and CMS. Two issues have been highlighted for the Low Level RF: transverse emittance growth (and associated luminosity drop) caused by CC RF noise, and large collimator losses following a CC trip. A prototype cryomodule with two CCs has been installed in the SPS, and tests have started in May 2018 with beam. This paper briefly reports on preliminary results from the SPS tests. It then presents emittance growth calculations from cavity field phase and amplitude noise, deduces the maximum RF noise compatible with the specifications and presents a possible cure consisting of a feedback on CC phase and amplitude. To reduce the losses following a CC trip we propose to implement transverse tail cleaning via the injection of CC noise with an optimized spectrum, which selectively excites the particles of large transverse oscillation amplitudes.

Slides THP2WC02 [1.943 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-HB2018-THP2WC02

Export •

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