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Brief Status of LHC Experimental Vacuum Project Ray Veness CERN TE/VSC
Brief Status of LHC Experimental Vacuum Project
Ray VenessCERN TE/VSC
Contents
o Overview of the upgrade projecto Project work packageso Recent changes to the project ‘environment’o Key activities in the 2012 shutdowno Key activities in the 2016 shutdown
o Diameters of central beampipeso New requests from the experimentso New data on beampipe alignmento Current issues under discussion
o Conclusions
LHC Experimental Vacuum LHCC Nov'10- R.Veness
Project Work Packageso Timescale
o Agreed May 2010o Covers period 2010-2015o Some modifications will not be complete
by the end of this periodo Volume of work
o 3 new beryllium chamberso 11 other new vacuum chamberso 8 other vacuum technology
developmentso Access procedures in activated
environmentso Development, design, construction,
installation, commissioningo Integrated project resources
o 27.4 person-years staff (~4.5 people average full-time)
o 6.5 person-years of visitorso 5982 kCHF of installed hardware and
2590 kCHF of VSC project costsLHC Experimental Vacuum LHCC Nov'10- R.Veness
Recent Changes to Project Environment
o Project now operatingo 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 scheduleo CERN White Paper ‘Provisional Planning for the LHC and
Injectors for the Next Decade’ in August 2010o 2014 shutdown becomes 2016 and 2018 shutdown becomes 2020-21
o ATLAS and CMS new PIXEL layer installation delayed to 2016o 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 Vacuum LHCC Nov'10- R.Veness
2012 Shutdown: ATLAS
o 4 new vacuum chamberso No change in envelope (beam aperture)o Replace stainless with aluminium for
reasons of:o Access and ALARA during interventionso Detector background
o Requires detector opening and removal of 6 vacuum chambers
LHC Experimental Vacuum LHCC Nov'10- R.Veness
Half-length of the ATLAS beam vacuum sector
2012 Shutdown: LHCbo Install 1 new chamber
and 2 new support systemso Install a replacement UX85/3
conical beryllium chambero Required due to varnished leaks
in the existing chambero 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 Vacuum LHCC 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 detectorso Add another layer of pixel
o IBL project in ATLAS and 4-layer PIXEL in CMSo 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-VSCo Design and production of 2 new beryllium
chambers and supportso Full opening of both experiments and
removal of all vacuum chambers (16 in total)o Complex retro-fit procedure inside existing
ATLAS detectoro Full procedures for interventions in a
radioactive detectorLHC Experimental Vacuum LHCC Nov'10- R.Veness
Installation of CMS beryllium
ATLAS beryllium pipe in the PIXEL
Renewed Discussions on Central Beampipe Diameters
o Situation upto summer 2010o Working towards a reduction from 58mm to 50mm diameter for
ATLAS and CMS in 2014o Aperture and machine protection were check OK by machine expertso We were awaiting final layouts in ‘Z’ to verify vacuum, impedance and
collimationo 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 2010o Request for sub-40mm diameter chamber for ALICE for 2016
o Working towards a decision on an acceptable diameter for the end of 2011o Request for sub-50mm diameter chamber for CMS for 2016o Request for sub-50mm diameter chamber for ATLAS for 2012
shutdowno ATLAS would like an ‘urgent’ spare chamber compatible with the IBL
LHC Experimental Vacuum LHCC Nov'10- R.Veness
New Information on Beampipe Alignment
LHC Experimental Vacuum LHCC Nov'10- R.Veness
M.Nessi (ATLAS) in LEB meeting of 4/11/10
W.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 Issueso ‘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
diametero ATLAS and CMS confirm they do not see the need for high-β after 2016o 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 Vacuum LHCC Nov'10- R.Veness
Conclusionso Consolidation and upgrade project
o Project is approved, personnel have been recruited and is now in progresso Work is progressing as planned for the 2012 shutdown changeso Recent changes to the LHC schedule and new requests from the experiments
mean that the work packages and associated resources must be revisedo 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 collimationo 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 diameterso 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 Vacuum LHCC Nov'10- R.Veness
