Towards A Scintillator SemiDigital Hadron Calorimeter: Progress at NIUNICADD - PowerPoint PPT Presentation

Title: Towards A Scintillator SemiDigital Hadron Calorimeter: Progress at NIUNICADD


1

• Towards A Scintillator (Semi)-Digital Hadron
  Calorimeter Progress at NIU/NICADD
• Jerry Blazey
• Northern Illinois University

2
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 830
• Muon Simulation Development Status Arthur
  Maciel Muon/PID Session Wednesday 100

3

• Generic Calorimeter Simulations
• First Design Prototype Results on Sensitivity
  and Threshold
• Optimization of Unit Cells
• Light Sensor Investigations

4
A Generic Calorimeter Number of Cells vs. Pion
Energy
0.25mip threshold
of Cells
100
E
20
For a 0.25 MIP threshold, cells
monotonically increasing with energy for a wide
range of cell sizes.
5
Digital vs. Analog
Energy 10,50 GeV p
Hits 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
6
Single Particle Energy Resolution

• Minimize (Eo-S(aiLi))2
• ai calculated for 10 GeV applied to all E,
  conservative
• i2 for EMCAL HCAL, also conservative

7
Single Particle Energy Resolution
Non-projective geometry
s/E
0.1
E
20
For lower energy particles digital approach has
superior resolution!
8
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 E10 GeV,
more bits superior.
So it works for single particles how about jets?
9
Toy Simulation Recipe for a Jet

• Determine resolution independent of algorithm
• For ZZ events PT order stable MC particles,
  ignore ns
• 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

10
ZZ Events Sanity Checks
Neutral hadron fraction
Stable MC particles
10
g fraction
25
Energy Fractions
11
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!
12
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)
13
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!
14
Hardware PrototypesStack, Layer, Unit Cell
WLS to Clear Fiber
MPTM
15
Cosmic Data with PMT Readout
ADC
ADC
11 p.e. peak 1MIP
16
0.25 MIP threshold efficient, quiet
17
Cell Response Uniformity Dispersion
Cell-to-cell 7 (dominated by fiber)
Uniformity 3
18
Other Uniformity Measurements
19
Absolute Response Measurements(Purple Cast,
Blue Extruded)
Since light ample, can optimize for ease of
construction
20
Surface Treatment/Wrapping
Paint easy, little light loss
21
Miscellaneous Measurementssource, glues, fibers
0.8 mm square Bicron
Extruded scintillator
1mm round Kuraray
Fiber has greatest affect on yield.
22
NICADD/Fermilab Extruder
23
Thickness Tolerance 2-3Response Depends weakly
on Thickness 20/mm
Thickness not an issue
24
Optimum Cell

• Hexagonal or Square
• 4 - 9 cm2
• Straight Groove
• High yield fiber
• Glued Fiber and Painted Surface
• Extruded (cut costs) _at_ 5mm
• But a bigger question is the light sensor
• PMTs costly, bulky
• we have been investigating APDs, MRS, Si-PM

My current guess
25
Hamamatsu Avalanche Photo-Diodes
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Cosmic MIP with Avalanche Photo-Diode
Hamamatsu S8550
27
Metallic ResistiveSemiconductor (CPTA)
Representative Spectrum
Center for Perspective Technologies and
Apparatus
28
Cosmics with MRS
60
0
50
51
29
Si-PMs (PULSAR/MEPHI) mounted on cell?
Representative Spectrum
Moscow Engineering Physics Institute
30
Cosmic Data with Si-PM
Number of P.E.
Comparable to PMT
31
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 or 1/cm2 for
Extruded/SiPM
32
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.
• Well be moving towards the next prototype