• Follow-up of actions from previous meetings
  • New web pages for V6.500 optics version -> JJ (pdf file)
    • New features have been added to the main page (e.g. hierarchy), the configuration pages and the table of contents (e.g. spreadsheet output). New features will be added for survey and aperture.
    • MG asked that the info for new web pages is not distributed until finalised.
  • Impact of quadrupole misalignment at SPS extraction on TI8 performance -> AK (pdf file)
    • Follow up of Werner's suggestion on moving down one quadrupole at TI8.
    • Maximum 10μrad of strength in correctors recover the orbit.
    • The change in dispersion is minimal (a few mm).
    • Updated optics files of the line from V. Kain have to be checked as well (additional tilt of SPS and horizontal displacement).
• Report from meetings
  • MEB -> MG
  • Problem with SpSSS geometry is being investigated. SR studied the impact of this on collimation (to be reported).
• DA comparison for V6.4 and V6.5 at injection -> RdM
  • Postponed for a subsequent meeting.
• Discussion of a new optics for IR7 (and IR3) -> TR (table)
  • Dispersion was compensated for gaining aperture in IR7 by changing phase advance and recovering it in IR4. Certain new rules for n1 have to be followed, i.e. n1=7 in QF and n1=6.7 in QD quadrupoles are the new specifications.
  • SF explained that due to a bug in the evaluation code, n1 in defocussing quads was reduced to 6.7. Otherwise, there would have not been enough no mechanical aperture.
  • Bad aperture at Q8 for Beam 1 (injection constraints) in IR2.
  • TR pointed out that aperture was increased for both beams in both IRs (see table).
  • Next step of the study will be IR3 (collimators should be untouched).
  • MG mentioned that TOTEM optics has also to be checked.
  • MG asked about the peak of beta in IR6 for Beam 2?  TR answered that there is no problem.
• Status of the optics studies for TOTEM -> HB (pdf file)
  • 90m optics for early commissioning is available for both beams.
  • Naming issues checked and fixed.
  • Small horizontal tune problem (ΔQ=0.083) to be recovered in IR4
  • Last task to include the file in V6.500 database (TR).
  • MG asked to check it with new IR7 optics (decreased phase advance)
  • SF suggested that the tune-shift can be accepted or its correction can be absorbed in IR1 and IR5.
  • HB mentioned a preliminary solution with QF and QD  and the trims in the arcs. SF argued trims are better for operation as there is no big impact to beta beating (5%). SF suggests to test the 90m even at injection, as there will be plenty of aperture, but maybe a problem with the peak at Q6. HB said that there should be no problem, but it will be checked.
  • MG asked whether there are any hardware limitations. HB said that it will be checked.
• AOB
  • Internal deadline for the EPAC papers was set 16th of July (papers to Oliver). Main issue is not to mention dates of LHC commissioning
  • LHC-MAC will take place next week (with talks by RA on collimation , SF on flat LHC beam upgrade option, MG on latest DA studies).

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