Summary notes of LCU meeting on 12/03/2007

Present: IA, RA, GB, RB, HB, RdM, UD, SF, MG, WH, JJ, MM, TP, VP, TR, FR, FS, RT, TW, FZ

Report from meetings

• Injection WG -> HB
  HB reported from the injection working group meeting on the 28 Feb 07, see the minutes. There were presentations on the sequencer, inject and dump mode and the status of protection devices. The next meeting will discuss the change from optics V6.500 to V6.501 (Q5, aperture..). HB, TR and MG will follow this up in contact with BT, in particular, HB for the impact of optics change in IR2/8 on the transfer line settings, MG to understand the availability of transfer line aperture from the layout database.
• MEB -> SF
  The work for the magnets going into the tunnel is nearly completed. The last magnet to be evaluated is Q2 for IR1. Some further meetings are planned to deal with spare magnets. 
• SLM -> MG
  MG reported about a new European activity led by Lyn Evans on for infrastructure and networks between institutes and possibly machine upgrades.
  The LHC cost to completion will be evaluated assuming 31/08/07 as the end date of the project.
  The request to IT to get support for FORTRAN was not successful. It is planned now to set up a limited support in the department, followed up by John Ferguson with contacts to PH.
  The US-Larp contribution to commissioning was discussed. Some people are expected to come from the US for each at least 3 month.
  Rüdiger Schmidt will organise a course on powering magnets, MG will inform the LCU members as soon as the details will be available.
  The question of the support for numerical computation for LHC impedance was discussed with Trevor Linnecar. A. Grudiev was responsible for this topic in the past. due to other charges the subject will be taken over by Tom Kroyer. Trevor asked to prepare a description of the ABP needs in order to allocate the appropriate resources. RA will provide the needs for the Collimation project, while MG will contact EM to assess the needs for the LHC ring in general.

• ICC -> MG
MG also reported from an ICC meeting. RA gave a presentation on collimation. There is good progress in the triplet heat exchanger repair. There were problems with theft and sabotage and the list of external people with access to the LHC tunnel will have to be reviewed.

Available Aperture in the Triplets IR1 and IR5 -> TW

TW gave a presentation on the available triplet aperture. The studies were done for optics version 6.500. During injection and ramp until squeeze the aperture will be limited by the arcs. During the squeeze, the triplet becomes the aperture limit. Tertiary collimators will have to me be moved in during the squeeze to protect the triplet.
The real aperture appears to be a bit below the specified 7.0 sigma aperture in terms of n1, particularly for beam2. This needs further checks and follow up on the aperture model used (TR). The aperture is already now sufficient (above 8 sigma) for the startup optics without crossing angle such that the collimation team can proceed with preparation for the commissioning.

At this point, FZ already mentioned an AoB item : The LHC commissioners in charge had a training meeting for transfer lines studies, where it was said that no aperture model exists for injection. Various information exists : HB and TR will follow this up with BT. MG will contact Samy Chemli for the database.

Trip report from Dafne -> FS

FS reported from a recent trip to DaΦne/Frascati, where he was involved in resonance driving term measurements with and without octupoles turned on. For this, a GUI is being developed in collaboration with Diamond which uses Mathlab. Such a GUI could be re-used for the implementation of the 1000-turn analysis with the MAD-X on-line model. A lot of data was taken and is being analyzed. The tune resolution reached about 5e-6.

Trip report from BNL and Fermilab -> RdM

RdM  reported on this trip to Fermilab and BNL, both mainly related to work on the LHC upgrade.
He worked with Mokhov at Fermilab on energy deposition estimates based on simulations using the MARS code and he also spent some time in the control room on studies using electron lenses (indeed they are electron cooling devices). The electron lenses can be used to affect single proton bunches and to change tunes by 2 to 3e-3. The electron lenses can also be used to clean the abort gap. Two are currently in operations: one affecting mainly the horizontal plane and the second the vertical plane. Work appears to continue also on muon colliders at FNAL. One of the problems is lattice design for large emittances, which could also be of interest for the LHC luminosity upgrade.
At BNL RdM worked with people involved in magnet designs relevant for the LHC luminosity upgrade. The studies include the possible of integration of high temperature superconducting magnets in the TAS. Work also continued on the dipole first LHC upgrade option.

AoB

MG mentions that following the results of hardware commissioning, there is a request to check if we could run without sextupoles and octupoles in one sector during early commissioning.
MG suggested to have reports from PhD students in the next meetings and he asked to get proposals for dates and titles to be scheduled in the forthcoming meetings.

Last update: 12-Mar-07

MG & HB

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