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Joint NDC-LNO sections meeting
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Joint NDC-LNO sections meeting
Introduction, Rogelio and Stefano
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This meeting was organized as a short, joint NDC-LNO meeting.
The main subject planned, the discussion of the cryostat alignment campaigns, with a presentation by Helene Mainaud Durand and Jean-Frederic Fuchs had to be postponed on short notice : mistakes were found in the alignment data that require a reanalysis.
Rogelio reported on recent LNO meetings and activities. The last meetings were focusing on the booster commissioning and modeling of solenoids. Slides and short minutes are on indico. There is good progress on the PS commissioning. Alex will report about this in the next meeting. Work is in progress on HL-LHC optics and scenarios. Riccardo is working on the optics details, including possible changes in position or optics related to the beam dump diluters TCDQ.
A more general subject followed up is to assure and further improve the smooth data flow from equipment data and machine alignment to our accelerator and optics physics side. This is followed up by Alex for the injectors and Riccardo for the LHC. It is planned to prepare a project proposal on this. Massimo said it will be important to get EN fully on board.
Stefano shows the current functional specification draft document in preparation ( EDMS # 2276602 ) on the
"Functional and operational conditions of the hollow lenses at HL-LHC".
NDC, activities and round table discussions
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NDC is providing training for its new members.
Simulation details were discussed yesterday with the FLUKA team. One recent feature is the implementation of bend crystals for ion collimation cleaning. Until recently this could only be done using GEANT4 and required a specific connection to GEANT4. It is now also possible with FLUKA and can profit from the existing FLUKA-SixTrack coupling.
Bjorn Lindstrom has started in NDC as fellow. He is looking into aperture modeling for HL-LHC for the current V1.5 optics.
This triggered a more general discussion on aperture information and the ongoing efforts to converge on a single source and make the complete set of aperture information for a given configuration easily available.
A rather complete set of aperture information as required for n1 calculations is provided on the MAD-X input level. Markers are used when needed to provide information like beam screen sizes extending beyond magnetic elements. Riccardo says that MAD-X technically can work with the aperture information extracted from the layout database ( https://layout.cern.ch accessible within CERN). The data is however currently not complete and not error free. Some details of beam pipe apertures for HL-LHC remain to be specified by the vacuum group.
Very detailed LHC aperture information for simulations have been available on the SixTrack level. The passage from the MAD-X to the SixTrack aperture model still requires some manual iterations.
Next NDC meetings : presentations by all students are planned.
LNO, activities and round table discussions
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Several of us are busy preparing and writing IPAC ontributions.
Concerning codes, Tobias commented on possibilities to modify the proton mass to match the value to the mass used by SixTrack.
A recent MAD-X issue reported was for the intrabeam module for coasting beams and is followed up.
Closed orbit finding with tapering still needs to be fully understood.
The scheduling for the next MAD-X release will be discussed today by Laurent and Tobias.
Laurent says he has been busy with the recent MAD-X courses and work for MAD-NG including the fascinating topic of normal forms.
Much of the OMC work is now directed towards the planned beams tests in autumn.
Details of the combined ramp and squeeze remain to be defined. Some reduction of beta* will be needed before reaching 7 TeV. The currently preferred strategy would be to ramp with only a minimal squeeze to maybe 7m.
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