Presents: RA, GB, CB, HB, MG, JBJ, JJ, AK, YP, SR, TR, TW.

• Follow-up of actions from previous meetings
  • Complete comparison between model from database and model used by collimation team (Action: JJ+SR). (pdf file)
    • A new query from the layout database was made: results are slightly different with respect to the previous aperture model.
    • Differences between the aperture model as obtained from the official database and from the Collimation team (set-up by SR) were found: a detailed analysis/comparison between the two models is required (Action: JJ, SR).
  • Beam 2 in MAD-X -> (Action: MG, TR)
    • Following the presentation at the last meeting, a number of additional checks were performed and few errors corrected.
    • A script to generate the files for SixTrack was prepared: it works fine.
    • Final tests with tracking inside SixTrack are required (Action: MG).
• Report from meetings
  • FQWG -> MG
    • Measurements of the field angle of LHC dipoles in the industry are problematic: they will be stopped and a request will be prepared to have additional measurements performed at CERN.
    • Magnetic measurements of the field quality of standard LHC beam screens: the agreement with previous results is not good for all the multipoles. This might be a consequence of the different manufacturing procedure. Additional tests will be performed.
  • LTC -> MG
    • Presentation of the installation schedule: the string 3 test is dropped due to the lack of DFBX. The question of postponing the shut-down of SMI18 to was raised: no official answer from AT so far.
    • Presentation of quench levels for LHC cryomagnets for proton operation:  the case of steady-state losses was considered. Detailed tables for the various classes of magnets were presented: at the present status of the study, the quench level for dipoles could be about a factor of 2 higher than assumed. However, there are cases for which the quench level is considerably lower than expected.
  • MEB -> MG
    • Magnet allocation continues:
      • Cryodipoles for sector 3-4 and 4-5
      • SSS for sector 7-8
    • Presentation of new magnets:
      • Warm dipoles for the spectrometer compensation in IP8
      • Special SSS for IP8
  • SLM -> MG
    • Clarification of the scope of ABP Fora: they are meant to be the general group meetings.
    • Chamonix organisation: meetings are in progress to define the various sessions.
    • Sector test meetings: a series of meetings are organised by M. Lamont to define activities in view of the LHC sector test. Following a request by OB to define a representative for the LOC section, MG proposed HB (as he is responsible for transfer line studies and injection) who accepted. There will be regular reports at the LOC meetings.
  • CWG -> RA
    • M. Lamont reviewed the estimates for beam losses during LHC operation: with respect to previous estimates a reduction by a factor of 2 is achieved.
    • The issue of water activation was considered: it will not be possible to release the water. The need for a remote handling system is under investigation.
• Optics squeeze generation for beam 1 in IP8 -> RdM
  • This point is postponed to a future meeting
• Solenoids in LHC using MAD-X -> HB (pdf file), AK (pdf file), TR (pdf file)
  • Follow up of discussions during second MAD-X Day
  • What is missing:
    • makethin for solenoids (no possibility of slicing a solenoid using standard multipole kicks).
    • tracking with solenoids in SixTrack.
    • information concerning experimental solenoids in LHC sequence file.
  • On-going work:
    • new implementation of makethin
    • cross-checks between tracking of thick solenoids with twiss command and PTC: excellent agreement found.
    • implementation of solenoids in MAD-X tracking module using Ripken formalism: tracking with thin solenoids does not agree with results from twiss and PTC for thick solenoids: small discrepancies found.
  • Future activities:
    • look at impact of experimental solenoids on coupling and possible correction strategies.
• AOB