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Detailed planning for extended maintenance and scheduled shutdowns at LHC, including activities, timelines, and objectives.
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Long shutdowns LS1, LS2, LS3 “Baseline” after Chamonix 2011 LS 1 Extendedmaintenance 2024 LS 2 LS 3 Extendedmaintenance
LHC draft version Oliver Bruning ACES Mar 2011
The next decade : the alternative version NOT FOR RE-DISTRIBUTION LS1 ……… LS2 (FPIX, PLT) 45mm beampipe. Fwd mu (YE4,CSC4,RE4, ME1/1) HO SiPM, HF PMT THIP BSC2 LHC: Splices, Collimation IR3 R2E changes Linac4 ?, PSB? Cryo-collimation? “driven by expts” (ATLAS wants 2019) HB/HE SiPM and granularity LHC: collimation, SPS.LHC mods Prepare RF upgrade & crab cav. 2-week 4-month: Open endcaps, New pix HB/HE? 4-month: Open endcaps? (FPIX,PLT, THIP) 8-week HF chain? Awaiting resource loading on LHC side provisional LHC planning promised for June importance of performance parameters after LS1 (nominal probable) TC/EAM working on provisional planning for TS(11-12), LS1 and TS(15-16/16-17)
Shutdowns & year-end Tech Stops Detailed objectives for each tech stop/shutdown period are interdependent and will evolve progressively depending on -the timing & duration of future stops/shutdowns -the achievements in past stops/shutdowns -the physics achievements (potential) for past (future) operation periods Activities must form part of a coherent plan covering extended technical stops & shutdowns (LS 1, LS 2, LS 3) in tune with the developing performance of LHC. The postponement of the 2011-13 shutdown (LS 1) to 2012-14, or maybe 2013-15 will: -delay the whole LS 1 task-list by 12-16 mo. -allow some tasks scheduled for LS 2 to be pre-empted. -pose a problem for upgardes scheduled for an earlier LS2 -tend to put pressure for more maintenance and repair tasks (& even upgrade tasks) during year-end stop 2011-12.
Baseline: Long Shutdown 1 Timeframe Est Integ Tasks lumi /fb-1 Items carried over from year-end stop 2011-12 (if no opening) 2013-15 5-15 Yoke Endcap disk 4 construction at +z and –z ends in situ. 4’th muon endcap stations +z and –z (CSC & RPC) 1’st endcap muon station readout granularity restoration +z and -z Beampipe region RP shielding + forward region opening under vac. -CASTOR, ZDC, TOT (?) reinstallable for special runs (HI etc) HO, HF & CASTOR calorimeters phototransducer change Muon sector collector move and TRB replacement Beampipe --> remove 59.6mm central beampipe/ install 45mm Barrel – endcap seal revision for colder Tracker operation Piping and test structures for 4-layer pix cooling Beam Scintillation Counter upgrade/replacement. + very many other infra & common systems consolidations. After which CMS should be ready for 13-14 TeV, 100+fb-1 and 1-2 x 1034cm-2s-1
B A E CMS: Shutdown 2012-14: + z seq Martin Gastal EN-MEF C H G The detailed planning already reached 300 discrete tasks and spans 5 May 2012 to 13 Mar 2012 (21 months) 6/7 configs
Year-end Technical Stops The experience of 2009-10 and 2010-11 shows that all 4 experiments can successfully complete complex interventions requiring partial opening in a year-end Technical Stop of ~10 - 12 weeks, with work spanning the CERN closure if necessary. Activities have already included : consolidation & first installation/upgrade : emergency repair and routine maintenance. The year-end Tech stops are an important ingredient in the overall consolidation and upgrade plan as well as being essential for maintenance and repair. So far experiment work stayed ~ within the shadow of LHC work. --> may not always be possible/desirable --> options for major interventions like 4-layer pixel insertion in a 3-4 month extended year-end stop The 2011-12 is very likely to be an extended year-end stop of 12 weeks It starts in 6 months time!!!
Year-end stop: 2011-12 Essential: Install the much-delayed ZDC crane (last chance - activation) Validate CASTOR calorimeter insertion with beampipe at vacuum. If we open the yoke (decision: Sept 2011), plan a “12 week” programme RP studies & shielding test Survey beampipe to confirm position Extract and repair forward pixel Install pixel luminosity telescope Investigate/improve pixel & strip Tracker humidity Limited muon system maintenance & upgrade test installations Consolidate yoke moving system Connect redundant compressor system in cryo hall (if funded 2011) Opening both ends doubles the risk but adds only 3-4 days compared to opening 1 end, provided we have full manpower. This workplan will cost 0.9-1.0 MCHF (Beampipe NEG pumping to be checked – bakeout operation adds 6 weeks if both endcap yokes already opened) After which CMS should be ready for 7-8 TeV, 15 fb-1 and 2-3 x 1033
Year-end stop: 2011-12 Assume a “12 week” stop, starting 6th Dec 2011, ending 15 Mar 2012 Approx 80 2-shift working days available following our usual planning rules Base planning on field experience from 2009-10 & 2010-11 (for TOTEM T1) + end fully open 15 - end fully open 21 + end pixel access available (+/- interchange poss) 24 (difficult by XMAS) - end pixel access available 30 Access to pixel and TK endflange 20 working days + end closing start 50 + end yoke closed 56 - end yoke closed 61 +end forward closed 68 -end forward closed 71 Beampipe pumpdown start 71 Magnetic field cycle and and ramp to 3.8T 76 Ready for beam 80 (If the 2 weeks XMAS site shutdown is included in the 12 weeks, subtract 10 days!!)
Beampipe: Mechanical design 3120 1900 RF HOM: shape OK Machine inner cones & support from Be or AlBe? Option to replace SS conical section (up to bellows & junctions with Endcap pipe) with AlBe. Lighter, as strong, reduces sag & activation. New pipe: SS+ Be: 22% more sag CMS E & I, for C. Schaefer
Beampipe Issues: mechanical tolerances The reduced radius can be viewed as a consolidation based on as-installed experience: Confirmed by CMS surveyors Not incl target to quad transfer < 1.0mm with AlBe Confirming with B=2T, 3.8T beampipe radiaography Conservative : over 3 yaers The requested 21.7 mm inner radius looks feasible
Beampipe: NI radiography in z slices Maxime Gouzevitch, Guacomo Squazzoni: for TIG, May 2011 0.35mm 2T (2011) differs from 3.8T (2010) by only a few mm.
Beampipe issues Would it be a problem to build the inner cones ~1900mm <z< ~1450mm of AlBe?