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Towards A Scintillator (Semi)-Digital Hadron Calorimeter: Progress at NIU/NICADD Jerry Blazey Northern Illinois University. LC Activities at NIU/NICADD. Scintillator (Semi-)Digital Hadron Calorimeter: Progress at NIU/NICADD – This Talk
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Towards A Scintillator (Semi)-Digital Hadron Calorimeter: Progress at NIU/NICADD Jerry Blazey Northern Illinois University Jerry Blazey NIU/NICADD
LC Activities at NIU/NICADD • Scintillator (Semi-)Digital Hadron Calorimeter: Progress at NIU/NICADD – This Talk • Test Beam Plans for Scintillator Hadron Calorimeter & Tail-catcher – Vishnu Zutshi – This Session • G4-based Simulation Status & Plans – Guilherme Lima – Session 7 Friday 8:30 • Muon Simulation Development & Status – Arthur Maciel – Muon/PID Session Wednesday 1:00 Jerry Blazey NIU/NICADD
“Generic” Calorimeter Simulations • First Design & Prototype & Results on Sensitivity and Threshold • Optimization of Unit Cells • Light Sensor Investigations Jerry Blazey NIU/NICADD
A Generic Calorimeter:Number of Cells vs. Pion Energy 0.25mip threshold # of Cells 100 20 E For a 0.25 MIP threshold, # cells monotonically increasing with energy for a wide range of cell sizes. Jerry Blazey NIU/NICADD
Digital vs. Analog Hits 10,50 GeV p Energy 10,50 GeV p Hits ECAL E ECAL Hits HCAL E HCAL Very similar correlations exist for hits or energy Between the EMCAL and HCAL Jerry Blazey NIU/NICADD
Single Particle Energy Resolution • Minimize (Eo-S(aiLi))2 • ai calculated for 10 GeV & applied to all E, conservative • i=2 for EMCAL & HCAL, also conservative Jerry Blazey NIU/NICADD
Single Particle Energy Resolution Non-projective geometry s/E 0.1 20 E For lower energy particles digital approach has superior resolution! Jerry Blazey NIU/NICADD
(s/E)dig (s/E)analog Resolution as a Function ofMultiple Thresholds or Bits 2 1 E * As in the previous slide, below 20 GeV digital resolution superior to analog. *For E>10 GeV, more bits superior. So it works for single particles how about jets? Jerry Blazey NIU/NICADD
Toy Simulation: “Recipe” for a Jet • Determine resolution independent of algorithm • For ZZ events PT order stable MC particles, ignore n’s • For charged hadrons assume perfect energy (from tracker) • Smear the energy of other particles • For neutral hadrons use resolutions for charge pions (just discussed). • For photons use s ~ 17%/sqrt(E) • Start with highest pT particle and cluster in 0.7 cone • Repeat for remaining particles • Add individual energies to get jet energy Jerry Blazey NIU/NICADD
ZZ Events: Sanity Checks Neutral hadron fraction Stable MC particles ~10% g fraction ~25% Energy Fractions Jerry Blazey NIU/NICADD
Jet E Resolution 0.04 s/E 0.01 rms used Jet E(GeV) So the idea holds water: At all energies 3x3 single threshold resolution comparable to analog! Jerry Blazey NIU/NICADD
Using full DHC E-flow: Jet Erec/Egen Calorimeter only Eflow s = 0.25 s = 0.16 ~60% better (Vishnu Zutshi, ECFA-DESY Workshop, 4/1/2003 http://nicadd.niu.edu, presentation 0046) Jerry Blazey NIU/NICADD
Full DHC Eflow: Jet Erec/Egen Eflow digital (2cm2 cells) Analog rather than hits s = 0.17 s = 0.16 Digital approach not yet optimized but performance comparable to analog! Jerry Blazey NIU/NICADD
Hardware Prototypes:Stack, Layer, & Unit Cell WLS to Clear Fiber MPTM Jerry Blazey NIU/NICADD
Cosmic Data with PMT Readout ADC ADC ~11 p.e. peak = 1MIP Jerry Blazey NIU/NICADD
0.25 MIP threshold: efficient, quiet Jerry Blazey NIU/NICADD
Cell Response Uniformity & Dispersion Cell-to-cell ~ 7% (dominated by fiber) Uniformity ~ 3% Jerry Blazey NIU/NICADD
Other Uniformity Measurements Jerry Blazey NIU/NICADD
Absolute Response Measurements(Purple: Cast, Blue: Extruded) Since light ample, can optimize for ease of construction Jerry Blazey NIU/NICADD
Surface Treatment/Wrapping Paint easy, little light loss Jerry Blazey NIU/NICADD
Miscellaneous Measurements:source, glues, fibers 0.8 mm square Bicron Extruded scintillator 1mm round Kuraray Fiber has greatest affect on yield. Jerry Blazey NIU/NICADD
NICADD/Fermilab Extruder Jerry Blazey NIU/NICADD
3mm 4mm 5 mm Thickness Tolerance: 2-3%Response Depends weakly on Thickness: ~20%/mm Thickness not an issue Jerry Blazey NIU/NICADD
Optimum Cell • Hexagonal or Square • 4 - 9 cm2 • Straight Groove • High yield fiber • Glued Fiber and Painted Surface • Extruded (cut costs) @ 5mm But a bigger question is the light sensor: PMTs costly, bulky we have been investigating APDs, MRS, Si-PM… My current guess… Jerry Blazey NIU/NICADD
Hamamatsu Avalanche Photo-Diodes Jerry Blazey NIU/NICADD
Cosmic MIP with Avalanche Photo-Diode Hamamatsu S8550 Jerry Blazey NIU/NICADD
Metallic ResistiveSemiconductor (CPTA*) Representative Spectrum *Center for Perspective Technologies and Apparatus Jerry Blazey NIU/NICADD
Cosmics with MRS 60 0 50 51 Jerry Blazey NIU/NICADD
Si-PMs (PULSAR/MEPHI*) mounted on cell? Representative Spectrum *Moscow Engineering Physics Institute Jerry Blazey NIU/NICADD
Cosmic Data with Si-PM Number of P.E. Comparable to PMT Jerry Blazey NIU/NICADD
Tabulated Specs/Studies * A. Bross et al., Fermilab FN-0733, 2003 ** B. Dolgoshein, “An Advanced Study of Silicon PM”, ICFA IB, 2002 *** V. Rykalin, NICADD presentation, http://nicadd.niu.edu , 2002 Estimate <$10 channel in bulk for Extruded/SiPM Jerry Blazey NIU/NICADD
Scintillator DHC Conclusions • Simulations indicate approach competitive with analog calorimetry • Prototypes indicate there is sufficient sensitivity (light x efficiency) & uniformity. • Now optimizing materials & construction to minimize cost with required sensitivity • SiPM and MRS look very promising All-in-all looks like a competitive option…. We’ll be moving towards the next prototype Jerry Blazey NIU/NICADD