ATLAS Construction: A Status Report Lake Louise Winter Institute February 2006 Anna Sfyrla

1. ATLAS Construction: A Status Report Lake Louise Winter Institute February 2006 Anna Sfyrla University of Geneva On behalf of the ATLAS Collaboration

2. LHC A Large Hadron Collider 7 TeV beam energy 27 km circumference operating luminosity 1034cm-2s-1 bunch spacing 25ns -> ~23 collisions per bunch crossing

3. ATLAS A Toroidal LHC Apparatus General purpose p-p detector Classic layered structure Shape defined by the ~4T toroidal magnet Length : ~ 46 m Radius : ~ 12 m Weight : ~ 7000 tons ~ 108 electronic channels ~ 3000 km of cables

4. The toroid system Superconducting air core toroids provide the (~4T) magnetic field for the muon spectrometer Barrel Toroid 8 separate coils Endcap Toroid 8 coils in a common cryostat Barrel toroid mechanical installation complete. Electrical and cryogenic connections being made now, To be completed for the first test by Spring 2006! Endcaps under Construction. Tests to be performed at 80K before moving to cavern

5. Muon Spectrometer Triggering - Resistive Plate Chambers (RPC) - Thin Gap Chambers (TGC) Precision Tracking - Cathode Strip Chambers (CSC) - Monitored Drift Tube Chambers (MDT) • Barrel Construction • Innermost chambers well advanced • Middle and outer chamber integration with RPCs and cosmic testing – in progress Barrel Installation • Already started and in good progress • To be completed by August Barrel Commissioning • Combined cosmics run together with Tile Calo Endcap ‘Big Wheel’ endcap under assembly Current speed not sufficient, being addressed with increased resources (plan in progress)

6. Calorimetry Electromagnetic Calorimeter - LAr sampling - Accordion shaped absorber plates Hadronic Calorimeter - LAr sampling in the inner FWD part - Iron/Scintillator sampling (Tile) surrounding the LAr parts Calorimeter barrel (+central solenoid) into their final position at the center of ATLAS (endcap installation in process) (November 2005) A cosmic ray muon registered in the barrel Tile Calorimeter

7. The Tracking System - Cylindrical cavity, length:6.8m, diameter:2.2m - Axial field of max strength 2T (superconducting solenoid in front of the ECAL - Precision tracking, 2ndary vertex detection, good time resolutionvs big amount of material (FE electronics, power cables, cooling pipes…) Transition Radiation Tracker (TRT) Straw tubes ~50K Barrel tubes & ~ 320K Endcap tubes ~4*105 channels 36 space points R < 1m Electron ID SemiConductor Tracker (SCT) Si Strip Detectors 4 Barrels & 2*9 Endcap Disks ~6*106 channels 4 space points 30cm < R < 52cm Pixels Si Pixel Detectors 3 Barrels & 2*3 Endcap Disks ~0.8*108 channels 3 space points 4cm < R < 12cm Big challenge: rad-hardness

8. The Tracking System -- pixels -- Probably the most challenging detector part of ATLAS! Very good progress in Pixel Sensors, Front End electronics and Readout, Mechanics, Staves and Disks Schedule affected by technical problems: - Faulty potting of controller chip on a fraction of barrel modules(solved) - Delamination of a fraction of barrel stave supports(solved) - Corrosion leaks in the barrel cooling tubes(highest priority is given to an optimum strategy for repair and rebuilding of staves) Schedule risk for the in time installation for the start up. (the Pixel sub-system can be installed independently from the rest of the ID) 2 completed pixels disks 2.2M channels each Completed barrel stave

9. The Tracking System -- SCT -- • Barrel assembly completed at Oxford • January-August 2005: Barrels shipped at CERN. • July-September 2005: 4-barrel + thermal enclosure integration • 99.7% of >3M channels fully functional inserting B6 into the thermal enclosure (7/05) a completed endcap disk • All disks for the 1st endcap finished, almost finished for the second one. • Disks assembled to endcaps in Liverpool and NIKHEF • New fabrication of LMTs (Low Mass Tapes for electrical services) because of material failures is on schedule Barrels and services

10. The Tracking System -- TRT -- • Barrel modules built and tested in US, re-tested at CERN • Integration of modules, FE electronics boards, gas and cooling with space frame  completed • Acceptance tests completed • Tests with cosmic rays performed since last summer • Leaks in the barrel cooling line manifolds, due to bad brazing: • redesign was adopted, and has been implemented. • Endcap wheels built and tested in Russia, re-tested at CERN • Acceptance tests completed, integration in progress. Cosmic rays recorded by the TRT

11. The Tracking System -- SCT & TRT integration -- • After reception tests,SCT to ‘cantilever’ stand • Test seals and functionality • Align ID rails • TRT on ‘ID trolley’ • Roll trolley over SCT maintaining alignment • Combined testing… For Barrels and Endcaps similar procedure but different tooling

12. The Tracking System -- SCT & TRT integration -- • Initial tests to take place: • Performance tests of SCT and TRT • Once the above tests accomplished, emphasis will be given in cosmics run (~4wks) • Lowering to the pit will take place at around June Friday, 17 February 2006

13. ATLAS Construction Status Summary • The installation schedule is very tight for the coming 15 months • Global commissioning of ATLAS is planned to take place April 07 – June 07, followed by ATLAS combined cosmics tests, planned for June 07 – August 07 • Last year’s progress has been very impressive, but the next year will be critical for the on schedule detector completion • Despite the delays (ex. Barrel Muon installation) and the still existing critical areas (ex. Pixels), large collective efforts are taking place to rearrange the schedule, in order to minimize the overall impact.

14. ATLAS Overall summary installation schedule Version 7.09