Author: Deniau, L.
Paper Title Page
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.