Author: Vollenberg, W.
Paper Title Page
WEPAB338 Amorphous Carbon Coating in SPS 3475
 
  • W. Vollenberg, P. Chiggiato, P. Costa Pinto, P. Cruikshank, H. Moreno, C. Pasquino, J. Perez Espinos, M. Taborelli
    CERN, Geneva, Switzerland
  
  Within the LHC In­jec­tor Up­grade (LIU) pro­ject, the Super Pro­ton Syn­chro­tron (SPS) needs to be up­graded to in­ject into the LHC higher in­ten­sity and brighter 25-ns bunch spaced beams. To mit­i­gate the Elec­tron Mul­ti­pact­ing (E.M.) phe­nom­e­non, a well-known lim­it­ing fac­tor for high-in­ten­sity pos­i­tively charged beams, CERN de­vel­oped car­bon coat­ings with a low Sec­ondary Elec­tron Yield (SEY). Dur­ing the 2016 & 2017 year-end tech­ni­cal stops, such coat­ings were de­posited on the inner wall of the vac­uum cham­bers of some SPS quadru­pole and di­pole mag­nets by a ded­i­cated in-situ setup. A much larger scale de­ploy­ment was im­ple­mented dur­ing the Long Shut­down 2 (2019-2020) to coat all beam pipes of fo­cussing quadrupoles (QF) and their ad­ja­cent short straight sec­tions. In this con­tri­bu­tion, we re­mind the mo­ti­va­tion of the pro­ject, and pre­sent the re­sults and the qual­ity con­trol of the car­bon coat­ing cam­paign dur­ing the lat­ter phase of im­ple­men­ta­tion.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB338  
About • paper received ※ 19 May 2021       paper accepted ※ 16 June 2021       issue date ※ 13 August 2021  
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THPAB235 Detailed Electromagnetic Characterisation of HL-LHC Low Impedance Collimators 4258
 
  • A. Kurtulus, C. Accentura, N. Biancacci, F. Carra, F. Caspers, N. Chitnis, F. Giordano, R. Illan Fiastre, S. Joly, I. Lamas Garcia, L. Mourier, E. Métral, S. Redaelli, B. Salvant, W. Vollenberg, C. Vollinger, C. Zannini
    CERN, Geneva, Switzerland
  
  The High Lu­mi­nos­ity Large Hadron Col­lider (HL-LHC) pro­ject will up­grade the LHC ma­chine to allow op­er­a­tion with in­creased lu­mi­nos­ity for the ex­per­i­ments. In order to achieve this goal, dif­fer­ent op­er­a­tional pa­ra­me­ters of the ma­chine need to be pushed be­yond the pre­sent de­sign val­ues, in­clud­ing the stored beam en­ergy. One of the main chal­lenges re­lated to the achieve­ment of the up­graded per­for­mance is the beam col­li­ma­tion sys­tem and its con­tri­bu­tion to the over­all ma­chine im­ped­ance bud­get. In this per­spec­tive, new low im­ped­ance col­li­ma­tors have been de­signed, fab­ri­cated, and in­stalled in the LHC. In this study, we will pre­sent their de­tailed elec­tro­mag­netic (EM) char­ac­ter­i­za­tion by means of radio fre­quency (RF) mea­sure­ments and EM sim­u­la­tions.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB235  
About • paper received ※ 19 May 2021       paper accepted ※ 19 July 2021       issue date ※ 10 August 2021  
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