Brief Status of LHC Experimental Vacuum Project Ray Veness CERN TE/VSC

Contents o Overview of the upgrade project o Project work packages o Recent changes to the project ‘environment’ o Key activities in the 2012 shutdown o Key activities in the 2016 shutdown o Diameters of central beampipes o New requests from the experiments o New data on beampipe alignment o Current issues under discussion o Conclusions LHC Experimental VacuumLHCC Nov'10- R.Veness

Project Work Packages o Timescale o Agreed May 2010 o Covers period o Some modifications will not be complete by the end of this period o Volume of work o 3 new beryllium chambers o 11 other new vacuum chambers o 8 other vacuum technology developments o Access procedures in activated environments o Development, design, construction, installation, commissioning o Integrated project resources o 27.4 person-years staff (~4.5 people average full-time) o 6.5 person-years of visitors o 5982 kCHF of installed hardware and 2590 kCHF of VSC project costs LHC Experimental VacuumLHCC Nov'10- R.Veness

Recent Changes to Project Environment o Project now operating o We have recruited 1 staff engineer, 1 staff technician, 1 fellow and 1 technical student for the project between July and October 2010 o Vacuum technology development and procurement of components is in progress o ‘White Paper’changes to LHC schedule o CERN White Paper ‘Provisional Planning for the LHC and Injectors for the Next Decade’ in August 2010 o 2014 shutdown becomes 2016 and 2018 shutdown becomes o ATLAS and CMS new PIXEL layer installation delayed to 2016 o ALICE replacement central beryllium pipe comes forward to 2016 [not yet in work packages] o LHCb new vertex detector in 2016 [not yet in work packages] LHC Experimental VacuumLHCC Nov'10- R.Veness

2012 Shutdown: ATLAS o 4 new vacuum chambers o No change in envelope (beam aperture) o Replace stainless with aluminium for reasons of: o Access and ALARA during interventions o Detector background o Requires detector opening and removal of 6 vacuum chambers LHC Experimental VacuumLHCC Nov'10- R.Veness Half-length of the ATLAS beam vacuum sector

2012 Shutdown: LHCb o Install 1 new chamber and 2 new support systems o Install a replacement UX85/3 conical beryllium chamber o Required due to varnished leaks in the existing chamber o No change to layout or material o Install and position new ‘spider’ supports for the UX85/2 and UX85/3 chambers o Re-optimised for lower-Z with material changed from aluminium to beryllium o Requires removal of 3 vacuum chambers and their supports LHC Experimental VacuumLHCC Nov'10- R.Veness Cross-section of LHCb experiment View inside magnet showing chambers and spider supports

2016 Shutdown: ATLAS and CMS o ATLAS and CMS consolidate PIXEL detectors o Add another layer of pixel o IBL project in ATLAS and 4-layer PIXEL in CMS o Make room for the detector by reducing the central beampipe diameter from 58 to (50mm) o Beam aperture for current and Phase-I upgrade optics (as per 2009) were studied o Implications for CERN TE-VSC o Design and production of 2 new beryllium chambers and supports o Full opening of both experiments and removal of all vacuum chambers (16 in total) o Complex retro-fit procedure inside existing ATLAS detector o Full procedures for interventions in a radioactive detector LHC Experimental VacuumLHCC Nov'10- R.Veness Installation of CMS beryllium ATLAS beryllium pipe in the PIXEL

Renewed Discussions on Central Beampipe Diameters o Situation upto summer 2010 o Working towards a reduction from 58mm to 50mm diameter for ATLAS and CMS in 2014 o Aperture and machine protection were check OK by machine experts o We were awaiting final layouts in ‘Z’ to verify vacuum, impedance and collimation o Request to study sub-40mm chamber for ALICE in 2018 o ALICE had stated that a 50mm chamber would not give enough space for a useful PIXEL upgrade o Situation as of Autumn 2010 o Request for sub-40mm diameter chamber for ALICE for 2016 o Working towards a decision on an acceptable diameter for the end of 2011 o Request for sub-50mm diameter chamber for CMS for 2016 o Request for sub-50mm diameter chamber for ATLAS for 2012 shutdown o ATLAS would like an ‘urgent’ spare chamber compatible with the IBL LHC Experimental VacuumLHCC Nov'10- R.Veness

New Information on Beampipe Alignment LHC Experimental VacuumLHCC Nov'10- R.Veness M.Nessi (ATLAS) in LEB meeting of 4/11/10W.Riegler (ALICE) in LEB meeting of 4/11/10 Data collected during the 2010 run has given new insight into the actual position of the beampipe on the interaction plane with respect to beam and detectors

Open Issues o ‘Tomography’ data from ALICE, ATLAS and CMS show good correlation with the originally installed positions of the chambers, however there are still open questions: o High-β optics may not be compatible with 50mm or less diameter o ATLAS and CMS confirm they do not see the need for high-β after 2016 o Is this an issue for an ATLAS ‘spare’ for the 2012 shutdown? o Does the beampipe move relative to the beam over a longer period? o Data still being collected by ATLAS et al. o Has there been any movement of central beampipes away from the interaction plane? o eg. tomography would not show ‘rotation’ of the chambers o Other issues: Vacuum (stability, pressures), impedance and heating, collimation check require the length of the smaller diameter section o Formal approval via Engineering Change Request and presentation to LHC Machine Committee will be required LHC Experimental VacuumLHCC Nov'10- R.Veness

Conclusions o Consolidation and upgrade project o Project is approved, personnel have been recruited and is now in progress o Work is progressing as planned for the 2012 shutdown changes o Recent changes to the LHC schedule and new requests from the experiments mean that the work packages and associated resources must be revised o Diameters of upgrade chambers for ALICE, ATLAS and CMS o Reduction of beampipe diameter to 50 mm has been verified for post-2016 operation for aperture, machine protection, mechanics and survey o Missing longitudinal layouts for verification of vacuum, impedance and collimation o Data from the experiments collected during the 2010 physics run are starting to give useful feedback as to the relative positions of beam, beampipe and detectors o This may yield some additional margin for reducing beampipe diameters o Spare beryllium chamber for ATLAS o The request for a sub-50mm spare beryllium chamber to be ready in time for a 2012 LHC shutdown is extremely challenging, from both technical and logistical points of view LHC Experimental VacuumLHCC Nov'10- R.Veness