Presents: HB, SF, MG, JBJ, JJ, AK, FS, TR, GRdM, AV

• Follow-up of actions from previous meetings
  • Comparison between aperture models: it will be presented at the next meeting -> JJ
  • Study of the beta-squeeze vs. time: discussions with F. Bordry stressed more details to be taken into account (L, R of the individual circuits). Data extraction from the official database already done by M. Zerlauth. Further analysis to be done -> MG
  • Correct field quality data for triplet quadrupoles: J. Kirby was contacted. Data for individual magnets are wrong and not coherent with those for the whole assembly. By the end of April a new set of data should be made available. -> FS
• Report from meetings:
  • TCC -> JBJ (pdf file)
    • Statement from LHC Project Leader: the slow installation rate is not an argument to slow down other activities, e.g. reduction of backlog dipoles to be re-adjusted towards ITP20.
  • MARIC -> JBJ (pdf file)
    • Presentation by D. Tommasini and L. Bottura on the new fiducialisation strategy and impact on MEB activities: strategy endorsed.
  • LHCOP -> OB
  • SLM -> OB
  • LTC -> SF, MG, JBJ
    • Presentation by L. Bottura of the new fiducialisation strategy and impact on MEB activities. Recommendation to complete the backlog of cryodipoles to be fiducialised asap.
    • Presentation by F. Zimmermann on heat load from e-cloud: it is no more an issue.
  • FQWG -> OB, SF, MG
    • Discussion on the beam screen contribution to the field quality
    • Measurements of prototype beam screens and simulations match well
    • Catalogue of beam screen effect for the whole set of magnets and beam screen orientation should be compiled via numerical simulations. The effect of vacuum pipe in MQWs will be studied too.
  • MEB -> SF, MG
    • 2 cryodipole's slots to be defined in sector 7-8
    • 7 cryodipole's slots to be defined in sector 8-1
    • Allocation of SSS is increasing pace
    • Strategy for pre-selection of cryodipoles for the next sectors, 4-5, 3-4, under discussion.
• New fellow in LOC section -> HB, AK (pdf file)
  • Main tasks:
    • maintenance and development of the tracking module in MADX
    • participation in the transfer line commissioning
  • MG suggests also to provide the maintenance of the beta-knobs developed by W. Wittmer.
• Status of computing for LHC studies -> FS
  • E. McIntosh produced a new version of the scripts to include also tune scans: it will be tested once D. Kaltchev will be at CERN.
  • New version of SixTrack including special routines for elementary function.
  • Main issue: computing support from IT when Eric will retire. Discussion are on-going between AB and IT Dept. Heads.
  • An assessment of the computing needs is required.
• The aperture module in MADX -> JBJ (pdf file)
  • The module was developed by I. Waarum with support from E. d'Amico.
  • Documentation already available from the MADX manual: an example should be provided.
  • JJ asks to have a clear definition of the n1 parameter. MG proposes to have a link from the MADX manual to the LHC-PN 111.
  • A number of details of the implementation should be clarified at the next meeting
• Latest results of the Dynamic Aperture studies for insertion quadrupoles -> MG (pdf file)
  • Tracking for MQM quadrupoles: done, but hysteresis
  • Tracking for MQY quadrupoles: done, but hysteresis and wider scan
  • Analysis of most dangerous quadrupole's location should be done using SODD
• AOB
  • OB will leave for two weeks.
  • A presentation on LOC section objectives and working packages will be made in one month -> OB.
  • SF: FQ issue of spool pieces correctors. Those produced by CAT are conform. The b3 correctors from TESLA are conform, but not the b4 and b5 correctors. The specifications have been revised:
    • Low order multipoles: from 100 units -> 250 units
    • High-order multipoles: stick to 100 units
    • Bound on systematic values over a batch of 50 magnets
  • M. Karppinen will produce an ECR.
  • HB: a presentation of the outcome of the MP Review should be scheduled for the next LOC meeting.

Colour code:

• Black: proposed agenda
• Red: outcome of discussion at the meeting