• Follow up of actions
  • Aperture analysis of the improved optics solutions prepared by TR-> MG
    • TR prepared new IR optics with improved aperture. MG will give a detailed presentation during the next meeting.
  • LHCWG-> MG (pdf file)
    • There are several action to be covered up during the following meetings.
      • Circumference difference between rings and non-reproducibility for the two aperture -> Luca Bottura, MG and GA.
    • Beam based measurement an correction of transfer function in separation dipoles using orbit feed-back (D2 in particular) -> tbd
    • Expected triplet quad roll error and related measurement procedures -> tbd
    • Global view of expected imperfections (follow-up of RT study for beta-beating) -> JPK, ET, MG
  • LTC action-> MG
    • Maximum bump amplitude at 450 GeV -> YP
    • Transparency of spectrometer polarity for LHCb (WH on Chamonix 2006) -> WH and/or YP
    • Injection optics for Pb collisions -> JJ
    • Energy spread via beam profile monitors (LCC) ->  tbd

• Report from meetings
  • MEB -> MG
  • Work continued on the allocation of SSS, SpSSS and MBWs.
  • Ranko Ostojic reported a problem detected during the installation of the first cold D4 separation dipole. Actually, the hardware type was wrong and the decision proposed was to move it to the equivalent slot but geometrical shifts were not able to be applied. A geometrical re-qualification of the magnet was necessary.
  • TCC-> MG
    • In IR3, cables are pulled in very tight bundles and cooling them will be very difficult. As a result,  magnets may not be able to be powered to their nominal values. Paul Prudlock asked to check the warm orbit correctors and the trim warm quadrupoles. For the latter there is no problem. Some work needs to be done on the orbit correctors. A rough 30% level was communicated  to Paul in order for him to be able to do a first check. TR will study the expected values for the orbit correctors and will report during next meeting.
  • MADX meeting -> FS
    • Piotr added many tools in MADX and thin lens tracing module was improved (varying fields)
• Phasing of collimation installation -> RWA (pdf file)
  • RWA presented the transparencies that he was going to show at the next MARIC meeting.
  • The collimation production and phases as well as the collimator general layout. Supports and infrastructure  are already installed, apart from tanks and vacuum pumping devices.
  • The production delays from the company (CERCA) are not related with technical issue. The delays have an impact on the collimator installation schedule.
  • A particular brazing problem was described, resulting in vacuum leaks, which is now fixed.
  • The collimator needs for the 450 GeV were presented: there is no additional limitation for low energy run for intensities of 3 x 10¹³ at 450GeV and 2 x 10¹²  at 1 TeV due to the revised installation schedule of collimators.
  • HB asked about the situation of injection TCIs. RWA answered that they will be delayed to phase 2.
•  Updates on optics studies -> TR
  • TR worked out an option of compensating the phase advance using only the quadrupoles in IR4. He has to check with JBJ the details of mechanical aperture in IR4.
  • There is an issue on the septum aperture and the renormalization of IR3 due to momentum collimation. This should be checked with JBJ.
• IR2 and 8 spectrometer compensation at 450 GeV  -> YP (pdf file)
  • YP presents the impact in aperture when having the experimental dipoles in IR2 and IR8 to their maximum strength, during the LHC collision run next year (LTC action).
  • The optics of both IRs is presented as well as the scheme of the experimental magnet compensation which creates the internal crossing angle.
  • The nominal cases are compared to the case of maximum strength in the spectrometer magnets (for the various crossing scheme flavors and polarities) creating a 16-fold increase in the folding angle and maximum in the orbit excursion on the second compensators.
  • In consequence, the main limitations come in both IRs in the location of the 2nd compensator magnet:
    • MBWMD in IR2 -> Available aperture of 9mm (with respect to 14mm for the nominal case), corresponding to 13σ of aperture loss.
    • MBXWH in IR8 -> Available aperture of 6mm (with respect to 12mm for the nominal case), corresponding to 15σ of aperture loss.
  • Given the tight aperture, it is felt safer to require that the spectrometer magnets are at their nominal value/16 at injection and the ramped. This, by the way, will be the configuration during routine operation runs.

• AOB
  • FS reports about recent issues concerning tracking/tools (pdf file):
    • He confirms that solenoids are not included in SixTrack.
    • A recent accident with the CASTOR system will be analyzed in details. For the time being storing tracking file to CASTOR should be disabled (MG circulated a mail from Eric McIntosh on how to do this).
    • A serious bug in the MAD-X to SixTrack converter was recently fixed.

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