Author: Lamont, M.
Paper Title Page
MOYAA01 The LHC from Commissioning to Operation 11
 
  • M. Lamont
    CERN, Geneva, Switzerland
  
  In 2011 the LHC moves from com­mis­sion­ing into the physics pro­duc­tion phase with the aim of ac­cu­mu­lat­ing 1fb-1 by the end of 2011. The progress from com­mis­sion­ing to op­er­a­tion is de­scribed. Em­pha­sis is put on the beam per­for­mance, but also on the per­for­mance of the dif­fer­ent hard­ware sys­tems. The role of col­li­ma­tion and ma­chine pro­tec­tion is dis­cussed, in view of the very high stored beam and mag­net en­er­gy. Com­ment: Other in­vit­ed pre­sen­ta­tions in this con­fer­ence will cover the ex­pe­ri­ence with beam in­stru­men­ta­tion and the up­grade pro­grammes.  
slides icon Slides MOYAA01 [7.410 MB]  
 
TUPZ016 First Run of the LHC as a Heavy-ion Collider 1837
 
  • J.M. Jowett, G. Arduini, R.W. Assmann, P. Baudrenghien, C. Carli, M. Lamont, M. Solfaroli Camillocci, J.A. Uythoven, W. Venturini Delsolaro, J. Wenninger
    CERN, Geneva, Switzerland
  
  A year of LHC op­er­a­tion typ­i­cal­ly con­sists of an ex­tend­ed run with col­lid­ing pro­tons, end­ing with a month in which the LHC has to switch to its sec­ond role as a heavy ion col­lid­er and pro­vide a use­ful in­te­grat­ed lu­mi­nos­i­ty to three ex­per­i­ments. The first such run in Novem­ber 2010 demon­strat­ed that this is fea­si­ble. Com­mis­sion­ing was ex­treme­ly rapid, with col­li­sions of Pb nu­clei achieved with­in 55 h of first in­jec­tion. Sta­ble beams for physics da­ta-tak­ing were de­clared a lit­tle over one day later and the final in­te­grat­ed lu­mi­nos­i­ty sub­stan­tial­ly ex­ceed­ed ex­pec­ta­tions.  
 
TUPZ028 Beam Based Optimization of the Squeeze at the LHC 1867
 
  • X. Buffat
    EPFL, Lausanne, Switzerland
  • M. Lamont, S. Redaelli, J. Wenninger
    CERN, Geneva, Switzerland
  
  The be­ta­tron squeeze is a crit­i­cal op­er­a­tional phase for the LHC be­cause it is car­ried out at top en­er­gy, with the max­i­mum stored en­er­gy and with re­duced aper­ture mar­gins in the su­per­con­duct­ing triplets. A sta­ble op­er­a­tion with min­i­mum beam loss­es must be achieved in order to en­sure a safe and ef­fi­cient op­er­a­tion. The op­er­a­tional ex­pe­ri­ence at the LHC showed that this is pos­si­ble. The op­er­a­tion in 2010 is re­viewed. In par­tic­u­lar, orbit, tune and chro­matic­i­ty mea­sure­ments are in­ves­ti­gat­ed and cor­re­lat­ed to beam loss­es. Dif­fer­ent op­ti­miza­tions are then pro­posed to­wards a more ef­fi­cient and ro­bust op­er­a­tion. The im­prove­ments ob­tained for the op­er­a­tion in 2011 are pre­sent­ed.  
 
WEPO031 The Magnetic Model of the LHC during Commissioning to Higher Beam Intensities in 2010-2011 2466
 
  • L. Deniau, N. Aquilina, L. Fiscarelli, M. Giovannozzi, P. Hagen, M. Lamont, G. Montenero, R.J. Steinhagen, M. Strzelczyk, E. Todesco, R. Tomás, W. Venturini Delsolaro, J. Wenninger
    CERN, Geneva, Switzerland
  
  The Field De­scrip­tion of the Large Hadron Col­lid­er (FiDeL) model is a set of se­mi-em­pir­i­cal equa­tions link­ing the mag­nets be­haviours es­tab­lished from mag­net­ic mea­sure­ments to the mag­net­ic prop­er­ties of the ma­chine ob­served through beam mea­sure­ments. The FiDeL model in­cludes the pa­ram­e­ter­i­za­tion of stat­ic com­po­nents such as mag­nets resid­u­al mag­ne­ti­za­tion, per­sis­tent cur­rents, hys­tere­sis and sat­u­ra­tion as well as the decay and snap-back dy­nam­ic com­po­nents. In the pre­sent paper, we out­line the re­la­tion­ship be­tween the beam ob­serv­ables (orbit, tune, chro­matic­i­ty) and the model com­po­nents dur­ing the com­mis­sion­ing to high­er beam in­ten­si­ties in 2010-2011, with an en­er­gy of 3.5 TeV per beam. The main rel­e­vant is­sues are (i) the op­er­a­tion at 2 A/s and 10 A/s ramp rate and their in­flu­ence on chro­mat­ic cor­rec­tion, (ii) the beta beat­ing and its re­la­tion to the knowl­edge of the re­sis­tive quadrupoles trans­fer func­tions and (iii) the ob­served tune decay at in­jec­tion en­er­gy and its pos­si­bles ori­gins.