Author: Timko, H.
Paper Title Page
TUPEA053 Feasibility Study of the AWAKE Facility at CERN 1253
 
  • E. Gschwendtner, C. Bracco, B. Goddard, M. Meddahi, A. Pardons, E.N. Shaposhnikova, H. Timko, F.M. Velotti, H. Vincke
    CERN, Geneva, Switzerland
  
  Plasma Wake­field ac­cel­er­a­tion is a rapidly de­vel­op­ing field which ap­pears to be a promis­ing can­di­date tech­nol­ogy for fu­ture high-en­ergy ac­cel­er­a­tors. The Pro­ton Dri­ven Plasma Wake­field Ac­cel­er­a­tion has been pro­posed as an ap­proach to even­tu­ally ac­cel­er­ate an elec­tron beam to the TeV en­ergy range in a sin­gle plasma sec­tion. To ver­ify this novel tech­nique, a proof-of-prin­ci­ple demon­stra­tion ex­per­i­ment, AWAKE, is pro­posed using 400 GeV pro­ton bunches from the SPS. De­tailed stud­ies on the iden­ti­fi­ca­tion of the best site for the in­stal­la­tion of the AWAKE fa­cil­ity re­sulted in propos­ing the CNGS fa­cil­ity as best lo­ca­tion. De­sign and in­te­gra­tion lay­outs cov­er­ing the beam line, the ex­per­i­men­tal area and all in­ter­faces and ser­vices will be shown. Among other is­sues, ra­di­a­tion pro­tec­tion, safety and civil en­gi­neer­ing con­straints will be raised.  
 
TUPME034 Experimental Studies for Future LHC Beams in the SPS 1652
 
  • H. Bartosik, T. Argyropoulos, T. Bohl, S. Cettour-Cave, J.F. Esteban Müller, W. Höfle, G. Iadarola, Y. Papaphilippou, G. Rumolo, B. Salvant, F. Schmidt, E.N. Shaposhnikova, H. Timko
    CERN, Geneva, Switzerland
  • A.Y. Molodozhentsev
    KEK, Ibaraki, Japan
  
  The High Lu­mi­nos­ity LHC (HL-LHC) pro­ject re­quires sig­nif­i­cantly higher beam in­ten­sity than presently ac­ces­si­ble in the LHC in­jec­tor chain. The aim of the LHC in­jec­tors up­grade pro­ject (LIU) is to pre­pare the CERN ac­cel­er­a­tors for the fu­ture needs of the LHC. There­fore a se­ries of ma­chine stud­ies with high bright­ness beams were per­formed, as­sess­ing the pre­sent per­for­mance reach and iden­ti­fy­ing re­main­ing lim­i­ta­tions. Of par­tic­u­lar con­cern are beam load­ing and lon­gi­tu­di­nal in­sta­bil­i­ties at high en­ergy, space charge for beams with 50ns bunch spac­ing and elec­tron cloud ef­fects for beams with 25ns bunch spac­ing. This paper pro­vides a sum­mary of the per­formed stud­ies, that have been pos­si­ble thanks to the im­ple­men­ta­tion of the SPS low gamma-tran­si­tion op­tics.  
 
TUPWA039 Identification of the SPS Impedance at 1.4 GHz 1793
 
  • T. Argyropoulos, T. Bohl, H. Damerau, J.F. Esteban Müller, E.N. Shaposhnikova, H. Timko
    CERN, Geneva, Switzerland
  
  In the SPS spec­trum mea­sure­ments of very long sin­gle bunches were used in the past to iden­tify sources of lon­gi­tu­di­nal mi­crowave in­sta­bil­ity. Shield­ing of the iden­ti­fied ob­jects sig­nif­i­cantly im­proved the beam sta­bil­ity. How­ever, lon­gi­tu­di­nal in­sta­bil­i­ties are still one of the lim­i­ta­tions for high in­ten­sity LHC beams in the SPS. Re­cently the same mea­sure­ment tech­nique was used again, re­veal­ing a strong high fre­quency res­o­nance. Dur­ing the slow de-bunch­ing with the RF switched off, the pres­ence of dif­fer­ent res­o­nant im­ped­ances leads to a line den­sity mod­u­la­tion at the res­o­nant fre­quen­cies. Lon­gi­tu­di­nal pro­files of bunches of var­i­ous in­ten­si­ties were ac­quired. For suf­fi­ciently high in­ten­si­ties their spec­tra show a fast grow­ing and strong mod­u­la­tion at 1.4 GHz. Mea­sure­ments using two trans­verse op­tics with dif­fer­ent tran­si­tion en­ergy are com­pared. Re­pro­duc­ing the mea­sure­ments with nu­mer­i­cal sim­u­la­tions, in­clud­ing the known SPS lon­gi­tu­di­nal im­ped­ances, al­lowed the pa­ra­me­ter range of this un­known source to be de­ter­mined. Pos­si­ble can­di­dates as im­ped­ance sources in the SPS ring are in­ves­ti­gated.  
 
TUPWA049 Short High-Intensity Bunches for Plasma Wakefield Experiment AWAKE in the CERN SPS 1820
 
  • H. Timko, T. Argyropoulos, H. Bartosik, T. Bohl, J.F. Esteban Müller, E.N. Shaposhnikova
    CERN, Geneva, Switzerland
  • A.V. Petrenko
    BINP SB RAS, Novosibirsk, Russia
  
  Ob­tain­ing the short­est pos­si­ble bunch length in com­bi­na­tion with the small­est trans­verse emit­tances and high­est bunch in­ten­sity – this is the wish list of the pro­ton-bunch dri­ven, plasma wake­field ac­cel­er­a­tion ex­per­i­ment AWAKE cur­rently under fea­si­bil­ity study at CERN. A few mea­sure­ment ses­sions were con­ducted to de­ter­mine the achiev­able bunch prop­er­ties and their re­pro­ducibil­ity. To ob­tain a short bunch length, the bunches were ro­tated in lon­gi­tu­di­nal phase space using the max­i­mum avail­able RF volt­age prior to ex­trac­tion. Mea­sure­ments were car­ried out in two op­tics with dif­fer­ent tran­si­tion en­er­gies. The main per­for­mance lim­i­ta­tion is lon­gi­tu­di­nal beam in­sta­bil­ity that de­vel­ops dur­ing the ac­cel­er­a­tion ramp. With lower tran­si­tion en­ergy, beam sta­bil­ity is im­proved, but the bucket area is smaller for the same volt­age. Based on the re­sults ob­tained, we shall dis­cuss the choice of op­tics, the im­pact of lon­gi­tu­di­nal in­sta­bil­i­ties, the im­por­tance of re­pro­ducibil­ity, as well as op­tions for im­prov­ing the bunch pa­ra­me­ters.  
 
WEPEA053 Progress with the Upgrade of the SPS for the HL-LHC Era 2624
 
  • B. Goddard, T. Argyropoulos, W. Bartmann, H. Bartosik, T. Bohl, F. Caspers, K. Cornelis, H. Damerau, L.N. Drøsdal, L. Ducimetière, J.F. Esteban Müller, R. Garoby, M. Gourber-Pace, W. Höfle, G. Iadarola, L.K. Jensen, V. Kain, R. Losito, M. Meddahi, A. Mereghetti, V. Mertens, Ö. Mete, E. Montesinos, Y. Papaphilippou, G. Rumolo, B. Salvant, E.N. Shaposhnikova, M. Taborelli, H. Timko, F.M. Velotti
    CERN, Geneva, Switzerland
  • E. Gianfelice-Wendt
    Fermilab, Batavia, USA
  
  The de­mand­ing beam per­for­mance re­quire­ments of the HL-LHC pro­ject trans­late into a set of re­quire­ments and up­grade paths for the LHC in­jec­tor com­plex. In this paper the per­for­mance re­quire­ments for the SPS and the known lim­i­ta­tions are re­viewed in the light of the 2012 op­er­a­tional ex­pe­ri­ence. The var­i­ous SPS up­grades in progress and still under con­sid­er­a­tion are de­scribed, in ad­di­tion to the ma­chine stud­ies and sim­u­la­tions per­formed in 2012. The ex­pected ma­chine per­for­mance reach is es­ti­mated on the basis of the pre­sent knowl­edge, and the re­main­ing de­ci­sions that still need to be made con­cern­ing up­grade op­tions are de­tailed.  
 
THPWO080 Operational Performance of the LHC Proton Beams with the SPS Low Transition Energy Optics 3945
 
  • Y. Papaphilippou, G. Arduini, T. Argyropoulos, W. Bartmann, H. Bartosik, T. Bohl, C. Bracco, S. Cettour-Cave, K. Cornelis, L.N. Drøsdal, J.F. Esteban Müller, B. Goddard, A. Guerrero, W. Höfle, V. Kain, G. Rumolo, B. Salvant, E.N. Shaposhnikova, H. Timko, D. Valuch, G. Vanbavinckhove, J. Wenninger
    CERN, Geneva, Switzerland
  • E. Gianfelice-Wendt
    Fermilab, Batavia, USA
  
  An op­tics in the SPS with lower in­te­ger tunes (20 ver­sus 26) was pro­posed and in­tro­duced in ma­chine stud­ies since 2010, as a mea­sure for in­creas­ing trans­verse and lon­gi­tu­di­nal in­sta­bil­ity thresh­olds, es­pe­cially at low en­ergy, for the LHC pro­ton beams. After two years of ma­chine stud­ies and care­ful op­ti­mi­sa­tion, the new “Q20” op­tics be­came op­er­a­tional in Sep­tem­ber 2012 and steadily de­liv­ered beam to the LHC until the end of the run. This paper re­views the op­er­a­tional per­for­mance of the Q20 op­tics with re­spect to trans­verse and lon­gi­tu­di­nal beam char­ac­ter­is­tics in the SPS, en­abling high bright­ness beams in­jected into the LHC. As­pects of lon­gi­tu­di­nal beam sta­bil­ity, trans­mis­sion, high-en­ergy orbit con­trol and beam trans­fer are dis­cussed.