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ATLAS Phase II For the High Luminosity LHC

ATLAS Phase II For the High Luminosity LHC. IPRD13 – Sienna Italy 07/10/2013. Dr. B. Todd Huffman on behalf of the AT LAS Collaboration ( Oxford University, United Kingdom ). Ladies and gentlemen , I think we’ve got it !. CERN, 4 July 2012.

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ATLAS Phase II For the High Luminosity LHC

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  1. ATLAS Phase IIFor the High Luminosity LHC IPRD13 – Sienna Italy07/10/2013 Dr. B. Todd Huffman on behalf of the ATLAS Collaboration ( Oxford University, United Kingdom ) B.Todd Huffman

  2. Ladies and gentlemen, I thinkwe’vegotit! CERN, 4 July 2012 Discovery of a Higgs-likeparticlecoupling to gaugebosons B.Todd Huffman

  3. Precision measurements of Higgs couplings Final states targeted to measure couplings (that have low signal rate at LHC): • ttH (with H γγ) • Allows precise measurement of top-Yukawa coupling • Cleanest signal (w.r.t WH/ZH)  S/B ~20% • S/√B ~6 with 3000 fb-1 (x2betterthan300 fb-1) B.Todd Huffman

  4. Physics at HL-LHC • Is this “Higgs” really THE Higgs?? • Also rare decays of known states (like top quarks) • Energy upgrade imminent!! • New states of matter to be found? • SUSY, Hidden SUSY, Z-prime, etc… • Highly exciting time! B.Todd Huffman

  5. Outline High-Luminosity • Detector challenges • Radiation damage • Background rates • Tracking • Rad. studies; choice of detector technology • Detector design concepts (baseline) • Trigger • HL-LHC studies on electrons and muons • Tracking ROI trigger • Conclusions B.Todd Huffman

  6. What we mean by “Phase 2”  Upgrade schedule 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 … 2030? LHC startup, √s= 900 GeV √s=7~8 TeV, L=6×1033 cm-2 s-1, bunch spacing 50 ns ~25 fb-1 Go to design energy, nominal luminosity √s = 13~14 TeV, L ~ 1×1034 cm-2 s-1, bunch spacing 25 ns Phase-0 LS1 >=75 fb-1 Injector and LHC Phase-1 upgrade to full luminosity √s = 14 TeV, L ~ 2×1034 cm-2 s-1, bunch spacing 25 ns Phase-I LS2 >=300 fb-1 HL-LHC Phase-2 upgrade, IR, crab cavities √s = 14 TeV, L = 5×1034 cm-2 s-1, luminosity leveling Phase-II LS3 ~3000 fb-1 B.Todd Huffman

  7. Detector Challenges • Peak luminosity (leveled)  1 to 5x1034cm-2s-1; 3000 fb-1 • Higher trigger rate •  need improved triggers • rather than simply raising • thresholds globally • Multiple interactions per crossing  <140> • Higher detector occupancy • Increasing reconstruction complexity • Increasing fluences >1016neq/cm2 close to the beam pipe • Increased radiation damage • Increased activation of materials • Aging electronics (obsolete technology) Baseline of the future Inner Detector traversed by an event with 230 Pile Up

  8. Phase-II: 2021/2022 (LS3) 18 month shutdown • ATLAS • detector upgrade • Replacement of the entire Inner Detector • LAr and Tile calorimeter electronics upgrades • Possible upgrade of Forward Calorimeters • Upgrade of Muon system • Muon Barrel and Large Wheel trigger electronics • Possible upgrades of TGCs in Inner Big Wheels • Coping with a track trigger • Forward detector upgrade • Target Absorber Secondaries (TAS) and • shielding upgrade • TDAQ upgrade • Software and computing • Various infrastructure upgrades • Common activities (installation, safety, …) Phase-II LoI: https://cds.cern.ch/record/1502664?ln=en

  9. The Detector Challenges roughly Split into Two Parts • <1m radius  Radiation Damageto components; ITK expected fluence at 14 TeV (3000 fb-1 ) • >1m radius  Pile-up & Trig. Rates;all of the detectors butwill show upgrades forMuons and Electrons ATLAS Inner Tracker (ITK) region

  10. RD50 Sensor Rad. Damage Studies Unannealed Neutrons 900 V 900 V Unannealed 26 MeV Protons All studied n-strip readout substrates become more and more similar with irradiation. This is true after neutron, proton and pion irradiations and with Hamamatsu and Micron devices. Micron Neutrons: A. Affolder, et. al., Nucl. Instr. Meth. A, Vol. 612 (2010), 470-473. Micron 26 MeV Protons: A. Affolder, et. al., Nucl. Instr. Meth. A, Vol.623 (2010), 177-179. HPK Neutrons: K. Hara, et. at., Nucl. Inst. Meth. A, Vol. 636 (2011) S83-S89. HPK 26 MeV Protons: New and unpublished A. Affolder – VERTEX 2011

  11. All Silicon Inner Tracker (ITK) • n-in-p advantages • Single-sided process (less expensive) • n+-in-n detectors • Double-sided (more expensive) • Guard rings @ ground near amplifiers • Both can work at HL-LHC rad. Levels • (If carefully designed)… • (And if they are kept cold ~-20o C) B.Todd Huffman

  12. All Silicon Inner Tracker for HL-LHC Classical layout with barrel cylinders and endcapdisks – “Utopia” • establishes baseline performance and cost • no special triggering layers cryostat wall solenoid coil long strip layers stub cylinder short strip layers beam pipe IP pixel layers • minimize gaps in coverage • last strip disk at z=3m, last pixel layer at 25-30cm • (improve double track resolution) • small “stub” layer in barrel • total of 14 hits with full coverage to η=2.5 • Pixels to η<2.7 (forward muon ID)

  13. Est. Hit occ. (Everywhere < 1%) Hit Occ. in % Simulations indicate no problems with pattern rec. at these levels. (note: 200 events pile-up for this study) B.Todd Huffman

  14. Pixel staves • Outer pixel layers • About 1.4m long and 5mm thick • Modules on both sides, overlap for full coverage, makes module mounting easier • n-in-p sensors (less costly) • Inner pixel layers • I-beam design linking neighbouring layers; Clamshell construction • Optimizes stiffness • n+-in-n sensors

  15. Phase2: Barrel Strip-Tracker End of Stave card • Strip barrel detector • 5 barrel layers, 3x short strips (23.8 mm) and 2x long strips (47.8 mm) • Strip Pitch – 74.5 mm • Stave-concept construction • Slide in – more reliable installation • Fully incorporated det. Services Need ~20000 of these …. B.Todd Huffman 15

  16. Tracker elements Barrel strip stave Concept: To create integrated, fully functional objects, which can be • Produced in parallel • Tested fully early in the assembly • Single staves are of limited value and loss of small number has small impact on project → Project robustness Outer pixel stave EC strip petal Pixel disk

  17. Radiation  tracker components • Optical data link • 4.8 Gbps • “Versatile link” • Pixels Micro-cables to escape highest Rad. zones • ~4m along the beam line • Then switch to optical readout • Strips  Versatile Link InGaAs GaAs B.Todd Huffman

  18. Inner Tracker Summary • Rad. Damage Studies show good performance for n-implant silicon detectors. • Cost considerations mainly driving decision to use n-in-p for Strips and outer pixels • Tracking coverage and hit occ. maintained. • Novel support structures under design • Stave concept • Cooling requirements mean Services (cooling, monitoring, control) incorporated into support structure. • Rad-hard and SEU tolerant Gbps readout systems needed B.Todd Huffman

  19. Part II: Increased Trigger rates • L0 added @ 500 KHz rate • L1 moves to 200 KHz rate • Important!: Maintain 20 GeV threshold muons(sharpen it up) and elec. (add tracks) • ROI seeded Tracks at L1, regional triggers • ROI = Region of Interest • Incorporated in FE electronics chips • Leads to trigger and electronics upgrades like muon system (but most sub-detectors need some upgrades) B.Todd Huffman

  20. Trigger Evolution – Phase-II • L1 : 200kHz o/p rate • Addition of Track information (L1Track) in Regions of Interest (RoI) • L0 : 500kHz o/p rate

  21. Muon Triggers Phase-1: • Additional Thin Gap Chamber (TGC) doublets (EIL4) • Include information from Tile Extended Barrel Phase-2: • New Small Wheel (NSW): Vector tracking based on sTGC and Drift tubes • Reject b.g. from n & g • Reduce fake muons • Rates for 20 GeVpT threshold @ 3x1034 cm-2s-1: • No change: 50kHz • All Phase-1 upgrades except NSW : 30 kHz • Adding NSW: 13 kHz

  22. L1Track • Maintain single lepton trigger thresholds at ~20GeV by adding track information at L1 • ~factor 5 rejection with 95% efficiency for offline selected events w.r.t. no L1track case Muon Trigger MU20: require track pT>15GeV in DR<0.15 Electron trigger: Require track in DR<0.15 0.67< E/p < 1.5 => Factor ~10 rate reduction

  23. Sharpening Trigger rates 1/E6 90% efficient ¤ Shown is a simple Power-law falling spectrum – Backgrounds fall faster (Red-Dashed) ¤ Idealized Trigger turn-on is made sharper in right-hand case (Solid Green) ¤ Events that Pass Trigger – (Solid Blue) ¤ ~4.5times reduction in rate in right-hand case ¤ In actual muontrigger, expect a factor of two reduction in rate. B.Todd Huffman

  24. CONCLUSIONS • Higgs Discovery motivates luminosity upgrade of LHC. • Proposed machine upgrade for Phase II (circa 2022) presents great challenges for the ATLAS detector. • Direct Radiation Damage and SEU’s • Increased backgrounds (pile-up events) • Shown how these are addressed in the Inner Tracker and the lepton triggers (obviously much more work is taking place in other sub-systems in parallel). • We should have an excellent detector during the next decade’s exciting discoveries! • THANK YOU. B.Todd Huffman

  25. BONUS MATERIAL B.Todd Huffman

  26. Strip staves

  27. Strip forward Detector • 7 Disks • Different types of modules • “Petal” concept • Continue tracking coverage |h|<2.7 • “Petalet” sub-unit under construction. Petalet B.Todd Huffman

  28. Stave Concept – Barrel • Barrel strip stave insertion and locking mechanics • Single-edge Mounting scheme • Staves “slide in” from end of barrel • Running theme Throughout inner tracker – Services incorporated in support structures. B.Todd Huffman

  29. HL-LHC Fluences at z=0 B.Todd Huffman

  30. Strip staves

  31. Strips electronics & readout(prototypes – close packed text: G. Viehhauser) • Sensors: n-in-p single sided design, 98 x 98mm2, 500V Max • Hybrids: glued onto sensor • ASICs: a 130 nm CMOS chipset • ABCn130: binary readout architecture (like SCT) but new protocol, 256 inputs for smaller hybrids, ROI and fast L1 trigger block • HCC: interface and module controller (1 per hybrid) • LV Powering: either serial (SP) or DC-DC at each hybrid/module • Additional powering and protection chipset, prototyped and new versions in development • Readout is being tested using stavelets (goal: good noise performance) Hybrids DC-DC converter board Example: DC-DC powered stavelet 4 modules 8 hybrids 160 ABCn 20k channels

  32. ATLAS Strip Read-Out(Barrel and Forward) • On-Detector • VTRx • GBTx • HCC HCC • HCC • Custom Rad-hard Off-Detector: COTS • Optical engines: • TX: Laser driver + laser arrays • RX: p-i-n array + TIA/discriminator • GBTx functionality in FPGA

  33. Radiation  tracker components GigaBit Transmitter (GBTX) Custom chipMultiplexer w. Forward Error correction (for Single Event Upset mitigation) SEU tests show they come in bursts. FeCcan correct up to 16 bits in a row. Data scrambled (helps DC balance) Responsivity of Photodiodes:Tough power budget decisions Makes Optical links unattractive choice at Pixel radii. B.Todd Huffman

  34. Why Upgrade? • Physics programme at LHC only begun with √s= 7-8 TeV collisions • After 4th July 2012… • Higgs boson precision measurements • Expected uncertainties on signal strength • reduced by a factor of 2-3 with HL-LHC • Ratio of partial widths to measure ratios of • couplings and probe new physics • at 5-15% level • Higgs self-coupling in SM becomes accessible only at HL-LHC luminosity • Probing new Physics • SUSY and other New Physics beyond SM • Enhancements in vector boson scattering amplitudes • Rare processes such as FCNC decays of top accessible to 10-5 Physics case: European Strategy Meeting (Sept. 2012, Kracow) http://indico.cern.ch/conferenceDisplay.py?confId=182232

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