Author: Migliorati, M.
Paper Title Page
WEPWA006 Beam Heat Load Measurements with COLDDIAG at the Diamond Light Source 2135
 
  • S. Gerstl, S. Casalbuoni, A.W. Grau, T. Holubek, D. Saez de Jauregui, R. Voutta
    KIT, Eggenstein-Leopoldshafen, Germany
  • R. Bartolini, M.P. Cox, E.C. Longhi, G. Rehm, J.C. Schouten, R.P. Walker
    Diamond, Oxfordshire, United Kingdom
  • M. Migliorati, B. Spataro
    INFN/LNF, Frascati (Roma), Italy
  
  Un­der­stand­ing the heat load from an elec­tron beam is still an open issue for the cryo­genic de­sign of su­per­con­duct­ing in­ser­tion de­vices. COLD­DIAG, a cold vac­uum cham­ber for di­ag­nos­tics was de­signed and built spe­cially for this pur­pose. With the equipped in­stru­men­ta­tion, which cov­ers tem­per­a­ture sen­sors, pres­sure gauges, mass spec­trom­e­ters as well as re­tard­ing field an­a­lyz­ers it is pos­si­ble to mea­sure the beam heat load, total pres­sure, and gas con­tent as well as the net flux and en­ergy of par­ti­cles hit­ting the cham­ber walls. Fol­low­ing a fail­ure after its first in­stal­la­tion in No­vem­ber 2011, COLD­DIAG was sub­se­quently re­in­stalled in the Di­a­mond stor­age ring in Au­gust 2012. We re­port on the pre­lim­i­nary re­sults that have been ob­tained since then.  
 
TUPWA044 Longitudinal Coupled-Bunch Oscillation Studies in the CERN PS 1808
 
  • H. Damerau, S. Hancock, M.M. Paoluzzi
    CERN, Geneva, Switzerland
  • M. Migliorati, L. Ventura
    Rome University La Sapienza, Roma, Italy
  
  Lon­gi­tu­di­nal cou­pled-bunch os­cil­la­tions are an im­por­tant lim­i­ta­tion for the high-bright­ness beams ac­cel­er­ated in the CERN PS. Up to the pre­sent in­ten­si­ties they are sup­pressed by a ded­i­cated feed­back sys­tem lim­ited to the two dom­i­nant os­cil­la­tion modes. In view of the pro­posed in­stal­la­tion of a wide-band feed­back kicker cav­ity within the frame­work of the LHC In­jec­tors Up­grade pro­ject (LIU), mea­sure­ments have been per­formed with the ex­ist­ing damp­ing sys­tem with the aim of di­men­sion­ing the new one. Fol­low­ing the ex­ci­ta­tion of well-de­fined os­cil­la­tion modes, damp­ing times and cor­re­spond­ing lon­gi­tu­di­nal kick strength are analysed. The paper sum­ma­rizes the re­sults of the ob­ser­va­tions and gives an out­look on the ex­pected per­for­mance with the new cou­pled-bunch feed­back.  
 
WEPEA042 The PS Upgrade Programme: Recent Advances 2594
 
  • S.S. Gilardoni, S. Bart Pedersen, C. Bertone, N. Biancacci, A. Blas, D. Bodart, J. Borburgh, P. Chiggiato, H. Damerau, S. Damjanovic, J.D. Devine, T. Dobers, M. Gourber-Pace, S. Hancock, A. Huschauer, G. Iadarola, L.A. Lopez Hernandez, A. Masi, S. Mataguez, E. Métral, M.M. Paoluzzi, S. Persichelli, S. Pittet, S. Roesler, C. Rossi, G. Rumolo, B. Salvant, R. Steerenberg, G. Sterbini, L. Ventura, J. Vollaire, R. Wasef, C. Yin Vallgren
    CERN, Geneva, Switzerland
  • M. Migliorati
    University of Rome "La Sapienza", Rome, Italy
  
  The LHC In­jec­tors Up­grade pro­ject (LIU) has been ini­ti­ated to im­prove the per­for­mances of the ex­ist­ing in­jec­tor com­plex at CERN to match the fu­ture re­quire­ments of the HL-LHC. In this frame­work, the Pro­ton Syn­chro­tron (PS) will un­dergo fun­da­men­tal changes for many of its main sys­tems: the in­jec­tion en­ergy will be in­creased to re­duce space-charge ef­fects, the trans­verse damper will be im­proved to cope with trans­verse in­sta­bil­i­ties the RF sys­tems will be up­graded to ac­cel­er­ate higher beam in­ten­sity and bright­ness. These hard­ware im­prove­ments are trig­gered by a se­ries of stud­ies meant to iden­tify the most crit­i­cal per­for­mance bot­tle­necks, like space charge, im­ped­ances, lon­gi­tu­di­nal and trans­verse in­sta­bil­i­ties, as well as elec­tron-cloud. Ad­di­tion­ally, al­ter­na­tive pro­duc­tion schemes for the LHC-type beams have been pro­posed and im­ple­mented to cir­cum­vent some of the pre­sent lim­i­ta­tions. A sum­mary of the most re­cent ad­vances of the stud­ies, as well as the pro­posed hard­ware im­prove­ments is given.  
 
WEPFI013 The Damped C-band RF Structures for the European ELI-NP Proposal 2726
 
  • D. Alesini, R. Boni, R. D. Di Raddo, V.L. Lollo, B. Spataro, C. Vaccarezza
    INFN/LNF, Frascati (Roma), Italy
  • L. Ficcadenti, V. Pettinacci
    INFN-Roma, Roma, Italy
  • M. Migliorati, A. Mostacci, L. Palumbo
    URLS, Rome, Italy
  • L. Serafini
    Istituto Nazionale di Fisica Nucleare, Milano, Italy
  
  The gamma beam sys­tem of the Eu­ro­pean ELI-NP pro­posal fore­sees the use of a multi-bunch train col­lid­ing with a high in­ten­sity re­cir­cu­lated laser pulse. The linac en­ergy booster is com­posed of 14 trav­el­ling wave C-Band struc­tures, 1.8 m long with a field phase ad­vance per cell of 2π/3 and a rep­e­ti­tion rate of 100 Hz. Be­cause of the multi-bunch op­er­a­tion, the struc­tures have been de­signed with a damp­ing of the HOM dipoles modes in order to avoid beam break-up (BBU). In the paper we dis­cuss the de­sign cri­te­ria of the struc­tures also il­lus­trat­ing the ef­fec­tive­ness of the damp­ing in the con­trol of the BBU. Pro­to­type ac­tiv­ity is fi­nally il­lus­trated.  
 
THOBB102 Beam Coupling Impedance Localization Technique Validation and Measurements in the CERN Machines 3106
 
  • N. Biancacci, G. Arduini, T. Argyropoulos, H. Bartosik, R. Calaga, K. Cornelis, S.S. Gilardoni, N. Mounet, E. Métral, Y. Papaphilippou, S. Persichelli, G. Rumolo, B. Salvant, G. Sterbini, R. Tomás, R. Wasef
    CERN, Geneva, Switzerland
  • M. Migliorati, L. Palumbo
    URLS, Rome, Italy
  
  The beam cou­pling im­ped­ance could lead to lim­i­ta­tions in beam bright­ness and qual­ity, and there­fore it needs ac­cu­rate quan­tifi­ca­tion and con­tin­u­ous mon­i­tor­ing in order to de­tect and mit­i­gate high im­ped­ance sources. In the CERN ma­chines, for ex­am­ple, kick­ers and col­li­ma­tors are ex­pected to be the main con­trib­u­tors to the total imag­i­nary part of the trans­verse im­ped­ance. In order to de­tect the other sources, a beam based mea­sure­ment was de­vel­oped: from the vari­a­tion of be­ta­tron phase beat­ing with in­ten­sity, it is pos­si­ble to de­tect the lo­ca­tions of main im­ped­ance sources. In this work we pre­sent the ap­pli­ca­tion of the method with beam mea­sure­ments in the CERN PS, SPS and LHC.  
slides icon Slides THOBB102 [7.224 MB]