Jerry Blazey NIU/NICADD 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 Scintillator (Semi-)Digital Hadron Calorimeter: Progress at NIU/NICADD – This Talk Test Beam Plans for Scintillator Hadron Calorimeter & Tail-catcher – Vishnu Zutshi – This Session 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 G4-based Simulation Status & Plans – Guilherme Lima – Session 7 Friday 8:30 Muon Simulation Development & Status – Arthur Maciel – Muon/PID Session Wednesday 1:00 Muon Simulation Development & Status – Arthur Maciel – Muon/PID Session Wednesday 1:00

Jerry Blazey NIU/NICADD “Generic” Calorimeter Simulations “Generic” Calorimeter Simulations First Design & Prototype & Results on Sensitivity and Threshold First Design & Prototype & Results on Sensitivity and Threshold Optimization of Unit Cells Optimization of Unit Cells Light Sensor Investigations Light Sensor Investigations

Jerry Blazey NIU/NICADD A Generic Calorimeter: Number of Cells vs. Pion Energy For a 0.25 MIP threshold, # cells monotonically increasing with energy for a wide range of cell sizes. 0.25mip threshold # of Cells E

Jerry Blazey NIU/NICADD Digital vs. Analog Very similar correlations exist for hits or energy Between the EMCAL and HCAL Energy 10,50 GeV  Hits 10,50 GeV  Hits HCALE HCAL Hits ECAL E ECAL

Jerry Blazey NIU/NICADD Single Particle Energy Resolution Minimize (E o -   a i L i  ) 2 Minimize (E o -   a i L i  ) 2 a i calculated for 10 GeV & applied to all E, conservative a i calculated for 10 GeV & applied to all E, conservative i=2 for EMCAL & HCAL, also conservative i=2 for EMCAL & HCAL, also conservative

Jerry Blazey NIU/NICADD Single Particle Energy Resolution Non-projective geometry For lower energy particles digital approach has superior resolution!  /E E

Jerry Blazey NIU/NICADD Resolution as a Function of Multiple Thresholds or Bits * As in the previous slide, below 20 GeV digital resolution superior to analog. *For E>10 GeV, more bits superior.  /E) dig  /E) analog E So it works for single particles how about jets? 1 2

Jerry Blazey NIU/NICADD Toy Simulation: “Recipe” for a Jet Determine resolution independent of algorithm Determine resolution independent of algorithm For ZZ events P T order stable MC particles, ignore ’s For ZZ events P T order stable MC particles, ignore ’s For charged hadrons assume perfect energy (from tracker) For charged hadrons assume perfect energy (from tracker) Smear the energy of other particles Smear the energy of other particles – For neutral hadrons use resolutions for charge pions (just discussed). – For photons use  ~ 17%/sqrt(E) Start with highest p T particle and cluster in 0.7 cone Start with highest p T particle and cluster in 0.7 cone Repeat for remaining particles Repeat for remaining particles Add individual energies to get jet energy Add individual energies to get jet energy

Jerry Blazey NIU/NICADD ZZ Events: Sanity Checks Stable MC particles Energy Fractions Neutral hadron fraction  fraction ~10% ~25%

Jerry Blazey NIU/NICADD Jet E Resolution rms used  /E 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 E rec /E gen ~60% better (Vishnu Zutshi, ECFA-DESY Workshop, 4/1/ presentation 0046)  = 0.25  = 0.16 Calorimeter only Eflow

Jerry Blazey NIU/NICADD Full DHC Eflow: Jet E rec /E gen  = 0.17  = 0.16 Eflow digital (2cm 2 cells) Analog rather than hits 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 ~11 p.e. peak = 1MIP ADCADC

Jerry Blazey NIU/NICADD 0.25 MIP threshold: efficient, quiet

Jerry Blazey NIU/NICADD Cell Response Uniformity & Dispersion Column1Mean Standard Error Median Mode#N/A Standard Deviation Sample Variance Kurtosis Skewness Range Minimum Maximum Sum Count22 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) CellGrooveAreaResponse HexagonSigma SquareSigma SquareSigma HexagonSigma HexagonSigma SquareStraight SquareStraight SquareStraight HexagonStraight HexagonSigma Since light ample, can optimize for ease of construction

Jerry Blazey NIU/NICADD Surface Treatment/Wrapping TyvekPaint VM 2002 MylarCM590CM500 Alum Foil UNPOLISHED TOP AND POLISHED BOTTOM POLISHED TOP AND POLISHED BOTTOM UNPOLISHED TOP AND UNPOLISHED BOTTOM Paint easy, little light loss

Jerry Blazey NIU/NICADD Miscellaneous Measurements: source, glues, fibers Extruded/Cast Extruded/Cast After/Before glue After/Before glue EJ500/BC600 EJ500/BC600 (optical glues) (optical glues) Y11/BCF92 Y11/BCF Extruded scintillator 1mm round Kuraray 0.8 mm square Bicron Fiber has greatest affect on yield.

Jerry Blazey NIU/NICADD NICADD/Fermilab Extruder

Jerry Blazey NIU/NICADD Thickness Tolerance: 2-3% Response Depends weakly on Thickness: ~20%/mm 3mm 4mm 5 mm Thickness not an issue

Jerry Blazey NIU/NICADD Optimum Cell Hexagonal or Square Hexagonal or Square cm cm 2 Straight Groove Straight Groove High yield fiber High yield fiber Glued Fiber and Painted Surface Glued Fiber and Painted Surface Extruded (cut 5mm Extruded (cut 5mm But a bigger question is the light sensor: PMTs costly, bulky we have been investigating APDs, MRS, Si-PM… 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 Resistive Semiconductor (CPTA*) Representative Spectrum *Center for Perspective Technologies and Apparatus

Jerry Blazey NIU/NICADD Cosmics with MRS

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, Estimate <$10 channel in bulk for Extruded/SiPM

Jerry Blazey NIU/NICADD Scintillator DHC Conclusions Simulations indicate approach competitive with analog calorimetry Simulations indicate approach competitive with analog calorimetry Prototypes indicate there is sufficient sensitivity (light x efficiency) & uniformity. Prototypes indicate there is sufficient sensitivity (light x efficiency) & uniformity. Now optimizing materials & construction to minimize cost with required sensitivity Now optimizing materials & construction to minimize cost with required sensitivity SiPM and MRS look very promising SiPM and MRS look very promising All-in-all looks like a competitive option…. We’ll be moving towards the next prototype