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Calorimeter R & D for Linear Collider

Calorimeter R & D for Linear Collider. Naba K Mondal TIFR, Mumbai. LC Calorimeter. Goal: Measure the Energy and mass of final state particles as precisely as possible. Many final state will contain particles escaping the detector. Need to measure missing energy as accurately as possible.

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Calorimeter R & D for Linear Collider

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  1. Calorimeter R & D for Linear Collider Naba K Mondal TIFR, Mumbai N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  2. LC Calorimeter • Goal: • Measure the Energy and mass of final state particles as precisely as possible. • Many final state will contain particles escaping the detector. Need to measure missing energy as accurately as possible. • Energy resolution of Calorimeter : • For most of the existing and planned detectors A ~.6-.7 • We need to achieve a value of 0.3 for LC calorimeter N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  3. LC Calorimeter • Why we need Few Examples • Measurement of Longitudinal coupling of W boson • Need to distinguish between nnWW & nnZZ final states. W/Z identification by mass reconstruction  in 4 jets N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  4. LC Calorimeter • Measurement of Higgs Self coupling in ZHH final state: • For a luminosity of 1 ab-1 , the signal is expected to be  at 3σ for α=0.60 while the signal goes to 6σ for α=0.30 • Measurement of Higgs to W boson branching ratios • The expected precision on BR(H→WW)downgrade by 22% when passing from α=0.30 to α=0.60. •  It is equivalent to a loss of 45% of the luminosity. N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  5. resolution Tracker better <= 70 GeV/c How to reach ? • For a 500 GeV e+e- collider– consider the process e+e- ---> ZZ consider the hadronic Z decay: • Energy sharing • Charged pions : ~60% • Photons : ~25-30% • Neutral hadrons: ~10-12% • Neutrinos :~small Use tracker in a magnetic field for Measuring charge particle energy. E.M. Calorimeter for photon energy measurment. HCAL for measuring the energy of neutral Hadrons only. Energy flow Algorithem N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  6. Design Optimisation for Energy Flow Challenges: Charged/neutral shower seperation requires High granularity in both longitudinal and Transverse direction to reconstruct showers Due to individual particles in 3D. Software to recognise tracks and clusters. Calorimeter has to be far enough from the Interaction point. Should have small radiation length, small interaction length and a matched readout granularity. N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  7. Talks on Calorimetry • Study of Scintillator based EM Calorimeter • H. Matsunaga • Hardware aspects of ECAl & HCAL opions from ALCPG • M.Oreglia • Simulation and Particle flow Algorithems for LC detectors • D.Chahraborty • Detector R & D Opportunities for a LC at Fermilab • Slawomir Tkaczyk • Development of RPC for INO • B.Satyanarayana • Heavy Ion detector R & D in India • Y.P.Viyogi N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  8. ALCPG Calorimetry:Hardware Aspects of ECAL and HCAL Options • ECAL R/D • Si-W • Scintillator-W • Hybrids • crystals • HCAL R/D • Scintillator • RPC • GEM Si-W design (SLAC/Oregon) => cost and minimal RM require compromise on E resolution by minimizing Si area (30 layers) and (Si thickness (300 mm)) Scint-W design (Colorado) => inexpensive, more samples – but poor granularity and larger RM Si-W-Scint. Hybrid (Kansas, K-State)=> thin Scint. layers, cheaper, more samples (incl. Si), retain granularity, keep RM small N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  9. ALCPG Calorimetry:Software and Simulation aspects STDHEP (pythia/pandora or particle gun) GISMO (SLAC) EGS, GEISHA xml geom. input Projective only Mokka (LLR) LCDMokka (DESY/ SLAC): G4, MySQL or xml geom. input LCDG4(NIU) G4, xml geom. input, Handles non-proj geometries Sio/lcio output for reco/analysis with JAS/Root/indep. AIDA-compliant code N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop + several standalone simulation programs

  10. Si-W geometry 6-inch f hexagonal Si wafers DC coupled Read out 1000 pads • power challenge • can dynamic range be realized? (0.1-2000 MIP) Transverse segmentation of 5mm x 5 mm possible N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  11. Scint-W Sampling Calorimeter Offset helps – but position resolution at low energy ?? Considering pixels of 50mm x 50 mm area to allow 1mm fiber curving 1.75 mm W; 2mm Sc ; 1mm gap N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  12. Smallest shower size in SD, but HY42 achieves almost the same E resolution with a slightly larger shower for 33% of the silicon cost Hybrid Si-W-Scint. Calorimeter N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  13. Fine granularity ECAL for the GLC calorimeter group • Currently studying fine granularityECAL with Pb/Sci sampling technique • examine “particle flow” analysis capability • Baseline design : tile/fiber ECAL • 4cmx4cmx1mm-Sci + 4mm-thick Pb • Option design : strip-array ECAL • 1cmx20cmx2mm-Sci + 4mm-thick Pb • Shower-max detector with scinti-strips • Conventional WLS readout • Directly-attached APD readout • Require multi-channel photon sensorsoperational in magnetic field N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  14. Test beams for new ECAL design • 2002 : T517 at KEK (e/m/p, 1-4 GeV) • tile/fiber ECAL, strip-array ECAL, scinti-strip SHmax • 2003 : test at DESY (e, 1-6 GeV) • scinti-strip SHmax • 2004 : T545 at KEK (e/m/p, 1-4 GeV) • tile/fiber ECAL, strip-array ECAL, scinti-strip SHmax • probably the last opportunity for KEK PS beamline Setup of T517 test beam measurement N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  15. Energy resolution Test beam GEANT3 simulation w/o photo statistics • If photo statistics is taken into account, beam test results are consistent with simulation N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  16. Linearity • Linearity : < 3.5% • < 1% above 2GeV • deviation at 1GeV : due to material in front of ECAL ? • In good agreement with simulation N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  17. Spatial resolution 4GeV electron event : Fitted to Gaussian Position resolution for 4GeV electron s =2.0mm around shower max N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  18. Angle measurement • Incident angle : 0 ~ 3 degree • Offset due to mis-alignment ? • Ignoring offset, angles are correctly measured within errors N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  19. Readout of scinti-strip • Strip-size : 20cm x 1cm x 1cm • Conventional readout : WLS + clear fiber to • MA-PMTs (tested) • HPDs (2004) • Directly-attached APDs on scinti-strip (tested) • SiPMs directly on WLS (2004) N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  20. Photon sensors • Multi-pixel Hybrid Photodiode (HPD) • DEP-HPD used for CMS-HCAL • We have tested Hamamatsu 64 pixels HAPD • Gain = 6 x 104 (good) • Commercially not yet available • Electron-bombarded CCD (EBCCD) • Suitable for fiber readout ～400 fibers/device possible • Sensitivity to single-photon • Gain is low (< 1000) • No timing information • Will test them with SHmax in 2004 test beam N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  21. Photon sensors (cont.) • SiPM • Micro-APD cells operated in Geiger mode • 1ch/device, compact, cheap (a few $/device) • High gain (~106), but significant noise rate • Can be directly attached to WLS fiber • Having only one SiPM in Japan, but expect more from DESY • Test in 2004 beam test ? N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  22. HCAL R & D Optimize application of Energy Flow Algorithms Separation of different components of jets Extremely fine segmentation of readout Readout pads of order of 1 cm2 Layer-by-layer readout Readout Digital (1 bit resolution) Semi-digital (say 2 bit resolution) Energy resolution preserved in MC simulation studies Challenges Develop active medium with required granularity in readout Reduce cost of electronic readout to O($1/channel) Intermediate goal Construction of 1 m3 prototype section 400,000 readout channels Candidate for active element Scintillator, Gas Electron Multipliers (GEMs), Resistive Plate Chambers (RPCs) N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  23. Scintillator DHCAL Concept Scintillator thickness 5 mm Hexagons of 9.4 cm2 area Trade-off segmentation with readout resolution Considering 2 – bit readout (= 3 thresholds) NorthernIllinois University Non-projective geometry N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  24. GEM DHCAL Concept Gas volume for ionization GEM foils for multiplication → perforated Pads for signal pick-up Universityof Texas at Arlington 9 channel GEM prototype using electronics developed for silicon readout (FNAL) 32 channel boards 3 mm gas gap N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  25. Technology/Design simulations:GEM Digital HCal (UTA) ArCO 2 0. 00 6.5mm 5 1 Cu . 0. 0 00 Kapton 5 G10 ArCO2 3.4 mm GEM 3.1 mm • Replaced scintillator with GEM’s – in Tesla TDR (Mokka) • Full & mixture approximation compared • Single pion studies to understand response and resolution • Analog vs Digital comparisons N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  26. GEM HCAL : Analog vs. Digital • ELive=SEEM+ W SGEHCAL • Obtained the relative weight W using two Gaussian fits to EM only vs HCAL only events • Perform linear fit to mean values as a function of incident pion energy • Extract ratio of the slopes  Weight factor W • E = C* ELive Digital Analog N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  27. GEM DHCal: response & E resolution • Single charged pions • 1 cm2 cells in HCal N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  28. RPC DHCAL Argonne, Boston, Chicago, FNAL • Major effort to: • prove reliable operation • vindicate simulation work • build cubic meter prototype for 2005 Mylar Pick-up pads Graphite Signal HV Gas Resistive plates Both groups agree Glass as resistive plates (NO permanent ageing ever observed) Work in avalanche mode (reduced cross talk, higher rate capability) N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  29. US chamber tests Two gas gaps of 0.64 mm each Gas Freon:Argon:Isobutane = 62:30:8 (in the past) Freon:Isobutane: SF6 = 94.5:5:0.5 (now) Readout pads of 1 cm2 High efficiency, wide HV plateau Little charge outside pad hit N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  30. HCal: gas vs. scintillator Needs revision with current algorithms RPC Scint. Analog: Digital: This is not a measure of ability to separate showers in a jet N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  31. DHCal: Density-weighted Clustering(NIU) di = k S (1/Rij) • Density-based clustering in both ECal and HCal • Clusters matched to tracks replaced by their generated p • For ECal clusters, use energy of assoc. cells • For HCal clusters, use nHit based E estimate N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  32. Analog vs Digital Energy Resolution GEANT 4 Simulation of SD Detector (5 GeV +) -> sum of ECAL and HCAL analog signals - Analog -> number of hits with 7 MeV threshold in HCAL - Digital Analog Digital Landau tails + path length fluctuations Gaussian N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  33. Single 10 GeVp+: event display comparison Blue: density = 1 Red: density = 2,3 Green: density > 3 Energy weighted Density weighted N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  34. RPC R & D work in India Looks a good candidate for Digital Calorimetry N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  35. PMD for Calorimeter active element ? STAR & ALICE • WA93 (S + Au, 200AGeV) : 8000 pads covering 3m2 • WA98 (Pb + Pb, 158 AGeV): 53000 pads covering 21m2 N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  36. N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

  37. Summary • Calorimetry is no longer the job of Calorimeter alone. • Need global collaboration among all sub detectors. • Need to define a model detector to check how such a collaboration will work effectively. N.K.Mondal, Calorimeter Summary, 17th Dec, 2002, ACFA Workshop

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