A vertex and tracking detector system for CLIC Andreas Nrnberg - PowerPoint PPT Presentation

A vertex and tracking detector system for CLIC Andreas Nürnberg (CERN) on behalf of the CLICdp collaboration International Conference on Technology and Instrumentation in Particle Physics 2017 (TIPP2017) Beijing, China, 22. – 26. May 2017

CLIC ◮ CLIC (Compact Linear Collider): linear e + e − collider proposed for the post HL-LHC phase ◮ Energy range from a few hundred GeV up to 3 TeV, staged construction ◮ Physics goals: ◮ Precision measurements of SM processes (Higgs, top) ◮ Precision measurements of new physics potentially discovered at 14 TeV LHC ◮ Search for new physics: unique sensitivity to particles with electroweak charge Possible layout near Geneva CLIC accelerating structure Legend Lake Geneva CERN existing LHC Potential underground siting: CLIC 380 GeV CLIC 1.5 TeV CLIC 3 TeV Jura Mountains IP Geneva 100 MV m − 1 50 km tunnel (3 TeV stage) A. Nürnberg: A vertex and tracking detector system for CLIC 24. 05. 2017 1

CLIC detector model Silicon tracker 11 . 4 m Vertex detector Forward detectors Fine grained calorimeters Superconducting 12 . 8 m solenoid, 4 T Return Yoke + Muon ID End coils A. Nürnberg: A vertex and tracking detector system for CLIC 24. 05. 2017 2

Detector requirements and experimental conditions ◮ Impact parameter resolution, 3 TeV CLIC 3 6 × 10 34 cm − 2 s − 1 2 θ )µm σ r ϕ = 5 ⊕ 15 / ( p [GeV] sin Luminosity Bunch separation 0 . 5 ns ◮ Momentum resolution, Buches / train 312 T = 2 × 10 − 5 GeV − 1 σ p T / p 2 Train duration 156 ns Repetition rate 50 Hz ∼ 10 − 5 ◮ Jet-energy resolution σ E E ∼ 3 . 5 % − 5 % Duty cycle Beam size σ x / σ y 45 nm × 1 nm ◮ No trigger, full readout of 156 ns bunch Beam size σ z 44 µm train ◮ Beam induced backgrounds: ◮ High rate: 3 γγ → hadron events per bunch crossing at 3 TeV More information on ◮ Requires high readout granularity experimental conditions and ◮ Requires precise timing ≤ 10 ns detector challenges → Talk by ◮ Moderate radiation environment: E. Sicking on Monday ◮ 10 − 4 LHC levels A. Nürnberg: A vertex and tracking detector system for CLIC 24. 05. 2017 3

Vertex and Tracking region A. Nürnberg: A vertex and tracking detector system for CLIC 24. 05. 2017 4

Vertex detector Goal: efficient tagging of heavy quarks through a precise determination of displaced vertices ◮ 3 µm single point resolution ◮ Material budget < 0 . 2 % X 0 per 560 mm layer (50 µm silicon sensor + 50 µm ROC) Multi-layer barrel and endcap pixel ◮ No liquid cooling, use forced air detectors flow cooling ◮ 560 mm in length ◮ Limit the power dissipation to ◮ Barrel radius from 50 mW cm − 2 , pulsed power 30 mm − 70 mm operation ◮ Spiral endcap geometry ◮ Hit time slicing of 10 ns A. Nürnberg: A vertex and tracking detector system for CLIC 24. 05. 2017 5

Vertex detector optimization - flavour tagging ◮ Use b- and c-tagging performance as benchmark for detector design ◮ Full simulation study (multivariate analysis), implementations following engineering studies: ◮ Geometry with x2 in material budget → 5 %-35 % degradation ◮ Spiral endcap geometry → Few regions with reduced coverage, otherwise similar performance ◮ 3 double layers vs. 5 single layers → small improvement for low-energy jets (less material per layer) Dijets at 200 GeV Dijets at 91 GeV Dijets at 91 GeV 1 Misidentification eff. Beauty Background 1.3 1.4 Misidentification Ratio Misidentification Ratio double_spirals_v2 spirals/CDR double_spirals/spirals double_spirals 1.2 -1 10 1.2 single layers 0 . 2 %X0 discs better 1.1 0 . 1 %X0 better per layer 1 1 LF Background 10 -2 double_spirals_v2 double_spirals 0.9 LF Background Charm Background θ ° =10 θ ° 0.8 =20 spirals better θ =10 ° θ =30 ° double layers double_spirals_v2/double_spirals θ ° θ ° =40 Beauty Background 0.8 =20 θ ° 1.4 =50 θ ° LF Background θ ° =60 =30 better θ ° =70 θ ° θ ° =80 =40 θ ° 1.2 =90 0.7 0.6 0.5 0.6 0.7 0.8 0.9 1 0.5 0.6 0.7 0.8 0.9 1 1 Beauty eff. Charm eff. 0.4 0.6 0.8 1 Charm eff. A. Nürnberg: A vertex and tracking detector system for CLIC 24. 05. 2017 6

Silicon tracker 4 . 6 m ◮ Radius ∼ 1 . 5 m, half-length ∼ 2 . 3 m ◮ 6 barrel layers, 7 inner + 4 outer endcap discs ◮ Radius of beam-pipe 3 m support tube increased to maximize forward acceptance ◮ 7 µm single point resolution ◮ 10 ns timestamping Material (vertex+tracker) ◮ Very light, 1 %X 0 − 1 . 5 %X 0 per layer ◮ Liquid cooling foreseen ◮ Good coverage, at least 8 3 m hits for tracks above θ = 8 ◦ A. Nürnberg: A vertex and tracking detector system for CLIC 24. 05. 2017 7

Tracker optimization ◮ Tracker design is outcome of optimization ] -1 µ 3 m studies in fast and full detector simulations ) [GeV Single µ µ 5 m − 3 10 µ θ = 90 ◦ 7 m ◮ Requirement on momentum resolution for µ 10 m µ T,true 15 m µ 20 m high momentum tracks lead to B = 4 T, 2 /p − 4 10 R = 1 . 5 m and single point resolution T p ∆ ( σ r ϕ = 7 µm σ Performance goal ◮ Good agreement between fast and full − 5 10 simulation 2 3 1 10 10 10 p [GeV] × -6 10 40 ] 10 0 -1 µ Single - B = 3.5 T T,true ) / GeV − 1 ) [GeV Fast simulation θ ° B = 4.0 T p = 500 GeV, = 90 Full simulation 35 10 − 1 B = 4.5 T θ = 90 ◦ B = 5.0 T θ = 40 ◦ 30 2 T B = 5.5 T /p 10 − 2 θ = 30 ◦ T θ = 20 ◦ p 25 σ (∆ p T / p 2 θ = 10 ◦ ∆ 10 − 3 RMS( 20 Performance goal 10 − 4 15 10 − 5 10 10 0 10 1 10 2 10 3 1200 1300 1400 1500 p / GeV R [mm] max A. Nürnberg: A vertex and tracking detector system for CLIC 24. 05. 2017 8

Beam induced backgrounds Occupancy / train ◮ Granularity of the tracker driven by 1 Inner Barrel 1 Barrel Inner Barrel 2 Inner Barrel 3 background occupancy Outer Barrel 1 − 1 10 Outer Barrel 2 ◮ Aim is to limit the occupancy to 3 % over 3 % limit Outer Barrel 3 the bunch train, need short strips/long − 2 10 pixels − ◮ Full simulation study: strip length for 3 10 50 µm r ϕ -pitch is limited to 1 mm–10 mm − 1000 0 1000 z / mm ◮ Actual granularity will depend on the chosen technology Occupancy / train 1 Inner Endcap 1 Inner Endcap 2 Endcaps Inner Endcap 3 Inner Endcap 4 Strixel Inner Endcap 5 Detector layers − 1 Inner Endcap 6 10 length / mm width / mm Inner Endcap 7 3 % limit Outer Endcap 1 Outer Endcap 2 Inner barrel 1–2 1 0 . 05 Outer Endcap 3 Outer Endcap 4 − 10 2 Inner barrel 3 5 0 . 05 Outer barrel 1–3 10 0 . 05 − 3 Inner disc 1 0 . 025 0 . 025 10 Inner discs 2–7 1 0 . 05 0 500 1000 1500 Outer discs 1–4 10 0 . 05 r / mm A. Nürnberg: A vertex and tracking detector system for CLIC 24. 05. 2017 9

Technology R&D programme Simulations Readout ASICs Sensors Interconnects/TSV Powering Cooling Light-weight supports Beam tests Detector integration → Integrated R&D effort addressing CLIC vertex and tracker detector A. Nürnberg: A vertex and tracking detector system for CLIC 24. 05. 2017 10

Silicon pixel detector R&D ◮ Different technology options to match the 50 µm planar sensor on CLICpix ASIC 1 . 6 mm different detector requirements ◮ Characterization of prototypes in lab and testbeam studies ◮ Vertex detector, difficult to achieve very good single-point resolution with very thin Capacitively coupled detector detection layers ◮ Planar hybrid pixel detectors ◮ Capacitively coupled pixel detector CLICpix CCPDv3 with active HV-CMOS sensor ( → Talk by M. Buckland on Thursday) ◮ Tracking detector, avoid costly bump SOI test chip HR-CMOS test chip bonding for large surface detector ◮ Integrated high-resistivity CMOS ( → Talk by M. Münker on Thursday) ◮ Silicon-on-insulator A. Nürnberg: A vertex and tracking detector system for CLIC 24. 05. 2017 11

Testbeam: active edge sensors ◮ To minimize material budget, minimize overlap of sensor tiles ◮ Active edge processing of planar sensor allows for seamless tiling without large impact on coverage ◮ Study feasibility of thin sensors with active edge using Timepix3 readout ASICs in testbeam ◮ In this example: grounded guard ring collects charge ⇒ lower efficiency understood using T-CAD simulations ◮ Other geometries, e.g. without guard ring are fully efficient to the edge 50 µm thick, GND guard ring 50 µm thick, GND guard ring T-CAD simulation of electric field in the edge region 2 1 90 TOT Row % 2 CLICdp Efficiency CLICdp Entries Grounded guard-ring 0.9 80 Work in Progress Work in Progress 0.8 60 70 1.5 0.7 60 Silicon 0.6 50 Air 40 1 0.5 40 0.4 30 0.3 20 0.5 20 0.2 0.1 10 0 0 0 0 -0.04-0.02 0 0.02 0.04 -0.04-0.02 0 0.02 0.04 Pos. rel. to last pixel [mm] Pos. rel. to last pixel [mm] A. Nürnberg: A vertex and tracking detector system for CLIC 24. 05. 2017 12