Author: De Maria, R.
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TUPRO001 Alternative High Luminosity LHC Matching Section Layout 990
 
  • B. Dalena, A. Chancé
    CEA/IRFU, Gif-sur-Yvette, France
  • R. De Maria
    CERN, Geneva, Switzerland
  • J. Payet
    CEA/DSM/IRFU, France
 
  Funding: The research leading to these results has received funding from the European Commission under the FP7 project HiLumi LHC, GA no. 284404, co-funded by the DoE, USA and KEK, Japan.
In the framework of the HL-LHC Upgrade project possible variants for the layout of the LHC matching section located in the high luminosity insertions are investigated. This layout is optimized to reduce the demand on the voltage of the crab cavities, it also improves the optics squeeze-ability, both in ATS[1] and non-ATS mode. Moreover the injection and transitions to collision optics are also discussed. [1] S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO001  
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TUPRO002 Fringe Fields Modeling for the High Luminosity LHC Large Aperture Quadrupoles 993
 
  • B. Dalena, A. Chancé, O. Gabouev
    CEA/IRFU, Gif-sur-Yvette, France
  • R. Appleby, D.R. Brett
    UMAN, Manchester, United Kingdom
  • R. De Maria, M. Giovannozzi
    CERN, Geneva, Switzerland
  • J. Payet
    CEA/DSM/IRFU, France
 
  Funding: The research leading to these results has received funding from the European Commission under the FP7 project HiLumi LHC, GA no. 284404, co-funded by the DoE, USA and KEK, Japan.
The HL-LHC Upgrade project relies on large aperture magnets (mainly the inner Triplet and the separation dipole D1). The beam is much more sensitive to non-linear perturbations in this region, such as those induced by the fringe fields of the low-beta quadrupoles. Analytical evaluations of detuning with amplitude and chromatic effects show that the effect is small, but not negligible. Therefore, the effect on long-term beam dynamics is evaluated via tracking simulations. Different tracking models are compared in order to provide a numerical estimate of this effect due to the proposed inner triplet quadrupoles. The implementation of the fringe fields in SixTrack, to be used for dynamic apertures studies, is also discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO002  
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TUPRO008 Specification of Field Quality of the Interaction Region Magnets of the High Luminosity LHC Based on Dynamic Aperture 1013
 
  • Y. Nosochkov, Y. Cai, M.-H. Wang
    SLAC, Menlo Park, California, USA
  • R. De Maria, S.D. Fartoukh, M. Giovannozzi, E. McIntosh
    CERN, Geneva, Switzerland
 
  Funding: Work partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404, and by the US LARP through US Department of Energy.
The high luminosity LHC upgrade (HL-LHC) requires new magnets in the low-beta interaction regions with a larger aperture than in the existing LHC. These include the Nb3Sn superconducting (SC) inner triplet quadrupoles, Nb-Ti SC separation dipoles D1 and D2, and SC matching quadrupoles Q4 and Q5. The large aperture is necessary for accommodating the increased beam size caused by significantly higher beta functions in these magnets in the collision optics. The high beta functions also enhance the effects of field errors in these magnets leading to a smaller dynamic aperture (DA). It is, therefore, critical to determine the field quality specifications for these magnets which 1) satisfy an acceptable DA, and 2) are realistically achievable. The estimates of expected field quality obtained from magnetic field calculations and measurements were used as a starting point. Then, based on the DA study, the field errors were optimized in order to reach an acceptable DA. The DA calculations were performed using SixTrack. Details of the optimization process and summary of the field quality specifications for collision and injection energies are presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO008  
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TUPRI014 Modelling and Long Term Dynamics of Crab Cavities in the LHC 1578
 
  • R. Appleby, D.R. Brett
    UMAN, Manchester, United Kingdom
  • J. Barranco García, R. De Maria, A. Grudiev, R. Tomás
    CERN, Geneva, Switzerland
 
  Funding: The research leading to these results has received funding from the European Commission under the FP7 project HiLumi LHC, GA no. 284404, co-funded by the DoE, USA and KEK, Japan.
The High Luminosity upgrade of the Large Hadron Collider (HL-LHC) aims to achieve an integrated luminosity of 250-300 fb-1 per year. This upgrade includes the use crab cavities to mitigate the geometric loss of luminosity arising from the beam crossing angle. The tight space constraints at the location of the cavities leads to cavity designs which are axially non-symmetric and have a potentially significant effect on the long term dynamics and dynamic aperture of the LHC. In this paper we present the current status of advanced modelling of crab cavities.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRI014  
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