Wednesday Summary of Working Group I

Initial questions I: 1) General boundary conditions: Topic for presentations during the WG boundary conditions related to radiation Goal of presentation present angular divergence of debris leaving the IP present energy distribution of debris leaving the IP present charge and mass distribution of debris present estimates for total power contained in debris present estimates for required absorber materials and thickness what additional radiation shielding is required in the IR for a factor 10 higher luminosity?

present questions still to be addressed in future studies Potential speaker Tanaji Sen magnetic TAS Assuming a TAS loaction between 19m and 23m from the IP what is the Tanaji Sen required diple field for deflecting 90% of the charged debris to amplitudes outside the nominal riplet aperture (63mm)? Does this value scale with the total heat ;load and luminosity?

Assuming a TAS loaction between 19m and 23m from the IP what is the required diple field for deflecting 90% of the charged debris to amplitudes outside a large triplet aperture (85mm)? Does this value scale with the total heat load and luminosity?

boundary conditions related to vacuum do we need beam screens in the triplet magnets if yes, how much aperture do we need to allocate for them Related questions given to the WG by the Work Shop Organizers required triplet aperture and crossing angle what are the minimum requried apertures of the experimental vacuum chamber for future detector upgrades?

LHC LUMI 2005; 1.9.2005; Arcidosso Oliver Brüning 1

Wednesday Summary of Working Group I

Initial questions II: 2) Upgrade issues for the detectors: Question / Topic radiation issues data taking issues goal of presentation what are the upgrades to the ATLAS and CMS detectors needed to withstand a factor 10 higher luminosity what bunch spacing scenarios are acceptible for a luminosity upgrade and how does they depend on the bunch luminosity?

what changes are needed for the experimental beam pipes (aperture and material choice)?

Potential speaker Fabrizio Palla space requirements and L* how much can we reduce L* for a future detector upgrade can quadrupole magnets be integrated into the detector design in order to reduce L*?

can quadrupole magnets be integrated into the detector design in order to reduce L*? Can we learn something from the experience in other machines (e.g. HERA)?

Michael Bieler & Peter McIntyre on ironless quads with integrated cooling Related questions given to the WG by the Work Shop Organizers what are the minimum requried apertures of the experimental vacuum chamber for future detector upgrades?

LHC LUMI 2005; 1.9.2005; Arcidosso Oliver Brüning 2

Wednesday Summary of Working Group I

main points from Tanaji Sen’s presentation I: -peak power deposition inside the triplet magnets is a factor 3 to 4 above the quench limit of the triplet magnets  any IR upgrade scenario requires an upgrade of the TAS absorber  TAS length and material?

-peak power deposition inside the triplet magnets leaves a safety factor 4 for the quench limit (including 3mm orbit errors) for nominal operation  how does the peak power deposition inside the triplet magnets scale with the orbit tolerances and how much can we increase the safety factor for the peak power deposition wih reduced tolerances on the closed orbit errors?

LHC LUMI 2005; 1.9.2005; Arcidosso Oliver Brüning 3

Wednesday Summary of Working Group I

main points from Tanaji Sen’s presentation II: -two options for dealing with the increased heat load inside the triplet magnets: 1) construct more robust triplet magnets that can tolerate the increased peak heat load :  how does the quench limit of different super conducting materials vary and are there SC materials that provide higher tolerances on the peak power deposition inside the magnets?

LHC LUMI 2005; 1.9.2005; Arcidosso Oliver Brüning 4

Wednesday Summary of Working Group I

main points from Tanaji Sen’s presentation III: -two options for dealing with the increased heat load inside the triplet magnets: 2) reduce the peak heat load with an upgrade of the TAS absorber:  how does the peak power deposition scale with the magnetic field strength and aperture of the magnets?

 magnetic TAS: requires integrated field of 10 Tm <-> 20 Tm LHC LUMI 2005; 1.9.2005; Arcidosso Oliver Brüning 5

Wednesday Summary of Working Group I

main points from Tanaji Sen’s presentation IV: -peak power deposition inside the triplet magnets depends on the material of the vacuum chamber -peak power deposition inside the triplet magnets depends on the orbit tolerances  scaling?

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Inner Triplet - baseline

Azimuthally averaged power density isocontours (mW/g) in the inner triplet of IR5

Peak power density - baseline

Peak power density in the first 2 radial bins for the baseline beam tube in Q1 and an alternative thinner tube.

Wednesday Summary of Working Group I

main points from Peter McIntyres’s presentation I: -power density deposited inside the triplet magnets reduces with L* if the triplet aperture is kept constant  move triplet magnets closer to the IP (scaling of losses with magnet field?) -power deposition inside the triplet magnets increases with L* with one assumes the magnet diameter is proportional to L*  move the triplet magnets further away from the IP -discussion showed that it is still a good idea to reduce L* but assumption of constant aperture must be revised LHC LUMI 2005; 1.9.2005; Arcidosso Oliver Brüning 9

Wednesday Summary of Working Group I

main points from Fabrizio Palla’s presentation I: -CMS detector might offer potential magnet locations for L* = 14 m with radial space of +/- 0.5 m (currently occupied by TOTEM and CASTOR) -ECAL installation is region of high radiation (L* = 3 m) -evaluate pro & con of a fixed installation (compatibility with access and vacuum bake out) and a movable installation (tolerances for magnet and detector movements) LHC LUMI 2005; 1.9.2005; Arcidosso Oliver Brüning 10

Muon chambers

Need better shielding of YE/4 (likely to be done before SLHC proper) Need better shielding for ME/1

Wednesday Summary of Working Group I

main points from Fabrizio Palla’s presentation II: -the situation for ATLAS is not as obvious (active area of the detector extends beyond TAS absorber)  we might have to look for different IR layout solutions for the two main experiments -the time required for an upgrade shut down must be balanced against a gain in integrated luminotisy  see the talk by Michael Bieler LHC LUMI 2005; 1.9.2005; Arcidosso Oliver Brüning 12

Wednesday Summary of Working Group I

main points from Michael Bieler’s presentation I: -HERA luminosity upgrade features 6 new superconducting magnets inside the detectors (2m and 3.7m long) -main problems related to the new installation: • water condenses on the cold magnets and drips into the detector • magnets are supported by steel cables and move by up to 1mm during the ramp • BPMs in the IR regions were initially exposed to synchtoron radiation LHC LUMI 2005; 1.9.2005; Arcidosso Oliver Brüning 13

Wednesday Summary of Working Group I

main points from Michael Bieler’s presentation II: -commissioning time for the HERA luminosity upgrade of 1.5 years to 2 years  the LHC IR upgrade must be robust in order to allow a fast commissioning time!

LHC LUMI 2005; 1.9.2005; Arcidosso Oliver Brüning 14

Mikrovertex-Detektor

ZEUS Detektor

Zentrale Driftkammer CTD Solenoid Magnet p e Vorwärts-Kalorimeter Zentrales-Kalorimeter Rückwärts-Kalorimeter

Wednesday Summary of Working Group I

summary: -not all questions could be answered but interests and worries have been communicated to all parties involved -many new questions -interest in scaling laws and concrete layout models for comparative studies -reduced L* is not excluded from the experiment (CMS) point of view -complicated IR designs that might imply a long commissioning time!

LHC LUMI 2005; 1.9.2005; Arcidosso Oliver Brüning 16