Overview of PhotoDetector Properties

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(No Transcript)
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Outline of Talk

• Overview of Photo-Detector Properties
• A Quick Look At
• MAPMT
• MCPMT
• SiPM
• Photo-Cathode RD
• Conclusion

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Overview of Photo-Detector Properties
Desirable Properties for Gamma-Ray Photo-Detectors

• Good Linearity
• Low Dark Noise
• Single pe Resolution
• Fast Signal

• High Gain
• High QE, 300-600 nm
• No After Pulsing
• Dynamic Range gt 1000

Adapted from J. Vanel, Cherenkov2005
Inexpensive would be Nice
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Overview of Photo-Detector Properties
Plot from Talk by J. Vanel, Cherenkov2005 K.
Arisaka
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Overview of Photo-Detector Properties
Conventional PMTs
Plot from Talk by J. Vanel, Cherenkov2005 K.
Arisaka
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Multi-Anode PMTs
Principle of Operation
Very Similar to Conventional PMT
Photo Drawing from Talk by Tomasz
Skwarnicki, BTeV
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Multi-Anode PMTs
Photo from Talk by Tomasz Skwarnicki, BTeV
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Multi-Anode PMTs
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Multi-Anode PMTs
Tests of R8900 at Argonne For Use in Trice
(ref. Byrum Talk this Workshop)
XY Stage
4-Decade Filter Wheel
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Multi-Anode PMTs
Test Results of R8900 at Argonne (Courtesy Bob
Wagner, ANL)
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Multi-Anode PMTs
Another Candidate 256 Channels
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Multi-Anode PMTs

• Nice Features
• High Gain
• Good Pixel Size
• Good pe Response
• Good Linearity Dynamic Range
• Good Dark Count Rates
• Fair Packaging,
• Some Improvement of Dead Space Needed

• Not-So-Nice Features
• Pixel Non-Uniformity 21 31 Requires
  Calibration, LUTs
• Triggering from Dynode Incurs
• Pixel Non-uniformity Penalty
• Gains Limited to 1E5 for NSB Rates,
• Reduces Resolution of Single pe Peak
• Quantum Efficiency 20, Could Use Improvement

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Micro-Channel Plates
Drawings from Paper by J. L. Wiza, NIM 162,
1976
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Micro-Channel Plates
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Micro-Channel Plates
Testing to Begin At ANL Looking at Fast Timing
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Micro-Channel Plates

• Nice Features
• Custom-Tailor Your Pixel Size
• Good pe Response
• Good Linearity Dynamic Range
• Good Pixel Uniformity, Might Still Need
  Calibration
• Low Dark Count Rates
• Excellent Timing Resolution

• Not-So-Nice Features
• No Dynode for Trigger
• Current-Return Path Not Well Defined Presently
• Slow Recovery of Individual Channels, mSec
• Quantum Efficiency 20, Could Use Improvement
• Packaging Needs Improvement for Dead Space
• Operates on 2000V

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Silicon Photo-Multipliers
Principle of Operation
Single Photodiode
SiPM
APD

• Mode of Operation Depends on
• Doping Purity of Silicon
• Bias Voltage
• Geiger Mode Needs Quenching

Adapted from Talk by Nepomuk Otte, SNIC06
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Silicon Photo-Multipliers
Principle of Operation
Photodiode Array Sum Individual Pixels
Premise Pixels are So Small
That 1 Pixel 1 pe
Photos from Talk by V. Saveliev, 5/4/06
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Silicon Photo-Multipliers

• SiPM Main Features
• Sensitive Size 1x1 mm2 24x24 576
  pixels 32x32 1024 pixels
• 2x2 mm2, 4x4 mm2 Possible
• Operating Voltage 40 to 60V
• Gain 105 up to 106
• Single Pixel Time Resolution
• 100ps
• Single Pixel Recovery Time
• 1 ?s
• No Sensitivity to Magnetic Fields

Triggered Data, 50 nS Gate
Adapted from Talk by V. Saveliev, 5/4/06
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Silicon Photo-Multipliers

• SiPM Features
• Dark Noise Rate
• 1 MHz/mm2 _at_ Room Temp
• 1 KHz/mm2 _at_ 100K
• Optical Crosstalk
• Hot-Carrier Luminescence
• Improvements with Trenching
• Dynamic Range
• 1 pe/pixel ? Limit Pixels

Adapted from Talk by J. Vanel, Cherenkov2005
Triggered Data, 1 mS Gate (ANL Data, Bob Wagner)
ANL Teststand
Adapted from Talk by Nepomuk Otte, SNIC06
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Silicon Photo-Multipliers

• Nice Features
• Small Size
• Low Operating Voltage
• Good pe Resolution (If Do It Right)
• Good Linearity, Fair Dynamic Range
• Good Timing Resolution
• Potential for Good QE (20 ? 40 ? 60)
• Potential for Cheap Production (Not There
  Yet)
• Large Arrays, Direct Integration of Electronics
  Possible

? MAGIC is Considering SiPMs for New
Telescope

• Not-So-Nice Features
• Dark Current Rate is Significant
• ? Needs Cooling, or Coincidence Trigger, or High
  Thresh.
• Optical Crosstalk Potentially a Problem
• QE Needs Improvement
• No Dynode for Trigger

? Not Quite in Production Yet
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Photo-Cathode RD
Slide Courtesy of J. Buckley
Higher QEgt higher cathode cost/area but smaller
telescopes with lower mechanical costs D2.5, and
smaller cathode area D2 (for a QE50, the
mechanical cost would be reduced by a factor of
gt2.4 and reduced cathode area would compensate
for higher cost/area)
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Photo-Cathode RD
Slide Courtesy of J. Buckley
MBE AlGaN/InGaN Cathode RD Washington University
Photocathode Group Buckley, Leopold and Rebillot
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Photo-Cathode RD
Slide Courtesy of J. Buckley
AlN-GaN-InN has a bandgap tunable between 0.8
eV (InN) and 6.2 eV (AlN) or 200 nm to gt 1000 nm
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Photo-Cathode RD
Detected QE with HPMT in our chamber
Slide Courtesy of J. Buckley
Burle (Photonis) is currently integrating one of
our AlGaN/InGaN cathodes into a conventional PMT
- but still more device features to implement
(thicker InN and higher In concentration for
improved long wavelength response, improved
lattice matching, intinsic gain), and many
manufacturing details.
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Conclusions

• Active Photo-Detector RD Programs in Many
  Technologies
• Many Innovative Ideas being Pursued
• Many Groups Active World-wide, in Development
  Evaluation
• Quite an Exciting Time for This Area
• ? We Can Only Profit from this Development
• Still Too Early to Tell Which Technology Will
  be Best
• Many Innovative Ideas being Pursued
• ? With New Approaches, Need to Choose
  Technology Carefully
• Personal Comments
• MAPMTs are Friendly Familiar Need Better QE,
  Uniformity
• MCPMTs Great for Fast Timing Need Additional
  Study
• SiPMs Promising Noise, Recovery, Production
  Issues
• APDs Good QE Need Cooling, Need Low-Noise
  Elec.
• HPDs Expensive, Good for B-Field, Better
  Options Exist

? Elec. Dev. Closely Coupled to Det. If ASICS,
Need Time