CLIC detector requirements and technologies first comparison with - PowerPoint PPT Presentation

CLIC detector requirements and technologies first comparison with the pp case Lucie Linssen, CERN on behalf of the CLIC detector and physics study (CLICdp) Lucie Linssen, FHC meeting, 27/1/2014 1

contents Contents: • CLIC detector requirement • Beam conditions at CLIC • CLIC detector concept(s) and some comparison with pp case • W/Z mass separation in W/Z => jj Results shown are from full Geant4-based detector simulation/reconstruction with overlay of beam-induced backgrounds Note on ATLAS, CMS and CLIC experiment comparisons: Performance comparisons between ATLAS, CMS and CLIC experiment were compiled by Erik van der Kraaij, CERN detector seminar October 2012: https://indico.cern.ch/conferenceDisplay.py?confId=210720 …with references therein. (You’ll find some of them in the backup slides) Lucie Linssen, FHC meeting, 27/1/2014 2

References and note on ongoing detector optimisation • CLIC CDR (#2), Physics and Detectors at CLIC, CERN-2012-003, arXiv:1202.5940 • CLIC CDR (#3), The CLIC Programme: towards a staged e + e - Linear Collider exploring the Terascale, CERN-2012-005, http://arxiv.org/abs/1209.2543 • Physics at the CLIC e+e- Linear Collider , Input to the Snowmass process 2013, http://arxiv.org/abs/1307.5288 CLIC has been using 2 detector concepts, derived from the ILC concepts. These are used in the references above and in most of the talk. We are currently doing new detector optimisation studies. With the aim of having one optimised concept by end 2014 Lucie Linssen, FHC meeting, 27/1/2014 3

physics aims => detector needs  momentum resolution: e.g. Smuon endpoint Higgs recoil mass, Higgs coupling to muons smuon end point  jet energy resolution: e.g. W/Z/h di-jet mass separation (for high- E jets)  impact parameter resolution: W-Z e.g. c/b-tagging, Higgs BR jet reco  angular coverage, very forward electron tagging + requirements from CLIC beam structure and beam-induced background Lucie Linssen, FHC meeting, 27/1/2014 4

CLIC machine environment (1) CLIC machine environment CLIC at 3 TeV L (cm -2 s -1 ) 5.9×10 34 BX separation 0.5 ns Drives timing requirements #BX / train 312 for CLIC detector Train duration (ns) 156 Rep. rate 50 Hz σ x / σ y (nm) ≈ 45 / 1 very small beam size σ z ( μm ) 44 Beam related background:  Small beam profile at IP leads very high E-field  Beamstrahlung  Pair-background  γγ to hadrons Lucie Linssen, FHC meeting, 27/1/2014 5

CLIC machine environment (2) Coherent e + e - pairs  7 x 10 8 per BX, very forward Simplified view: Incoherent e + e - pairs Pair background  3 x 10 5 per BX, rather forward • Design issue (high occupancies)  gg → hadrons gg → hadrons •  3.2 events per BX Impacts on the physics •  main background in calorimeters Needs suppression in data  ~19 TeV in HCAL per bunch train Beamstrahlung  important energy losses right at the interaction point 3 TeV E.g. full luminosity at 3 TeV: √s 5.9 × 10 34 cm -2 s -1 energy spectrum Of which in the 1% most energetic part: 2.0 × 10 34 cm -2 s -1 Most physics processes are studied well above production threshold => profit from full luminosity Lucie Linssen, FHC meeting, 27/1/2014 6

γγ => hadrons background Average p T of background particles is ~2 GeV Total ~19 TeV deposited in the calorimeters, within detector acceptance. Ratio 10/1 for Endcaps/Barrel Lucie Linssen, FHC meeting, 27/1/2014 7

CLIC detector concepts … in a few words … complex forward return yoke with region with final Instrumentation beam focusing for muon ID strong solenoids 4 T and 5 T fine grained (PFA) calorimetry, 1 + 7.5 Λ i , 6.5 m ultra low-mass main trackers: vertex detector TPC+silicon (CLIC_ILD) with 25 μm pixels all-silicon (CLIC_SiD) Lucie Linssen, FHC meeting, 27/1/2014 8

CLIC_ILD and CLIC_SiD Two general-purpose CLIC detector concepts Based on initial ILC concepts (ILD and SiD) Optimised and adapted to CLIC conditions CLIC_ILD CLIC_SiD 7 m Lucie Linssen, FHC meeting, 27/1/2014 9

CLIC time structure of the beam CLIC time structure - not to scale - 156 ns 20 ms CLIC Bunch separation = 0.5 ns 1 train = 312 bunches Repetition rate = 50 Hz CLIC has a very low duty cycle:  No need for a trigger, read out all data after 156 ns bunch train  The beam structure is used to apply power pulsing to all detectors  Key ingredient to achieve low mass in the vertex/tracker  Key ingredient to achieve highly compact calorimetry 10 Lucie Linssen, FHC meeting, 27/1/2014

comparison CLIC  LHC detector In a nutshell: CLIC detector: LHC detector: • High precision: • Medium-high precision: • Jet energy resolution • Very precise ECAL (CMS) • => fine-grained calorimetry • Very precise muon tracking (ATLAS) • Momentum resolution • Impact parameter resolution • Overlapping beam-induced background: • Overlapping minimum-bias events: • High background rates, medium energies • High background rates, high energies • High occupancies • High occupancies • Cannot use vertex separation • Can use vertex separation in z • Need very precise timing (1ns, 10ns) • Need precise time-stamping (25 ns) • “No” issue of radiation damage (10 -4 LHC) • Severe challenge of radiation damage • Except small forward calorimeters • Beam crossings “sporadic” • Continuous beam crossings • No trigger, read-out of full 156 ns train • Trigger has to achieve huge data reduction Lucie Linssen, FHC meeting, 27/1/2014 11

Challenges in LC detector R&D These requirements lead to the following challenges: Vertex and tracker Very high granularity Dense integration of functionalities ultra – light Including ~10 ns time-stamping Super-light materials Low-power design + power pulsing Air cooling Calorimetry ultra – heavy Fine segmentation in R, phi, Z and compact Time resolution ~1 ns Ultra – compact active layers Pushing integration to limits Power pulsing Lucie Linssen, FHC meeting, 27/1/2014 12

CLIC vertex detector Vertex + forward tracking CLIC_ILD • ~25×25 μm pixel size => ~2 Giga-pixels • 0.2% X 0 material par layer <= very thin ! • Very thin materials/sensors • Low-power design, power pulsing, air cooling • Aim: 50 mW/cm 2 • Time stamping 10 ns • Radiation level <10 11 n eq cm -2 year -1 <= 10 4 lower than LHC Very challenging and very active R&D project ! Lucie Linssen, FHC meeting, 27/1/2014 13

CLIC vertex detector R&D Hybrid approach pursued: (<= other options possible) • Thin (~50 μm ) silicon sensors • Thinned High density ASIC in very-deep-sub-micron: • R&D within Medipix/Timepix effort • Low-mass interconnect • Micro-bump-bonding (Cu-pillar option, Advacam) • Through-Silicon-Vias (R&D with CEA-Leti) • Power pulsing • Air cooling CLICpix 64×64 pixels 64×64 pixel demonstrator Fully functional • 65 nm technology CLICdp • 25× 25 μm 2 pixels participates in • 4-bit TOA and TOT information 1.6 mm RD53 (pixel ASIC • 10 nsec time-slicing R&D in 65 nm) • Power 2 W/cm 2 (continuous) • together with With power pulsing ATLAS and CMS • 50 mW/cm 2 Lucie Linssen, FHC meeting, 27/1/2014 14

CLIC_SiD main silicon tracker all-silicon tracker in 5 Tesla field chip on sensor 1.3 m Aim: ~1%X 0 per layer in the outer tracker R&D still at an early stage Lucie Linssen, FHC meeting, 27/1/2014 15

calorimetry and PFA Jet energy resolution and background rejection drive the overall detector design => => fine-grained calorimetry + Particle Flow Analysis (PFA) What is PFA? Typical jet composition: 60% charged particles 30% photons 10% neutrons  Always use the best info you have: 60% => tracker 30% => ECAL 10% => HCAL Hardware + software ! Lucie Linssen, FHC meeting, 27/1/2014 16

calorimetry and PFA FPA-based simulation Simulated image (to determine depth of tungsten HCAL) (gives good feeling of the granularity) Lucie Linssen, FHC meeting, 27/1/2014 17

PFA calorimetry at CLIC ECAL technology Si or Scint. (active) + Tungsten (absorber) cell sizes 13 mm 2 or 25 mm 2 30 layers in depth jet energy resolution HCAL Several technology options: scint. + gas Tungsten (barrel) , steel (endcap) cell sizes 9 cm 2 (analog) or 1 cm 2 (digital) 60-75 layers in depth Total depth 7.5 Λ i High precision on jets  ECAL +HCAL have to fit inside coil  CLIC needs Tungsten absorber in HCAL  Requires beam tests to validate Geant4 (no jet clustering, without background overlay) Lucie Linssen, FHC meeting, 27/1/2014 18

Linear Collider calorimetry R&D With major technological prototypes in beam tests in recent years Lucie Linssen, FHC meeting, 27/1/2014 19

Analog HCAL: scintillator/tungsten HCAL tests with 10 mm thick Tungsten absorber plates, Tests in 2010+2011 with scintillator active layers, 3×3 cm 2 cells => analog readout visible Energy longitudinal shower protons profile, pions CERN SPS 2011 good agreement with Geant4 Lucie Linssen, FHC meeting, 27/1/2014 20