Recent news about SiPM based applications R

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Recent news about SiPM based applications RD in
DESY

• Nicola DAscenzo
• University of Hamburg - DESY

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Calorimetry at International Linear Collider

• The ILC physics requires a calorimeter with
• High granularity (Good jet energy resolution)
• Ermeticity and good missing energy resolution
• Compactness (The detector has to stay inside the
  magnetic coil)

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The scintillator tile hadron calorimeter

• Sampling calorimeter absorber stainless steel,
  active medium plastic organic scintillator.
• Along the magnetic field direction it extends in
  -220 cm lt z lt220 cm
• It covers the detector along the radius in the
  region 180 cmlt r lt 290 cm
• The test beam prototype 1 m3 .
• Test beam prototype 38 layers, 216 channel per
  layer.

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SiPM a good photodetector for hadron calorimetry

• The good SiPM for this application
• Low noise above the suggested cut on the mip
  spectrum (Controlled dark rate and cross talk)
• Light Yield not exceeding the saturation
  behaviour of the device.
• Stable and controlled production

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The scintillator direct readout

• The direct readout is easier to extend to
• a large scale production.
• The solution which respects the required bounds
• on the parameters
• Blue Sensitive?
• Green sensitive and large?

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The MPPC by Hamamatsu
Blue sensitive Silicon PhotoMultiplier, Suitable
for the direct coupling
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Direct readout with MPPC

• Readout of a plastic scintillator tile directly
  and comparison with the mediated green fiber
• Tile wrapped with a 3M reflector. In case of the
  direct readout, only a window of 1mm x 1mm is
  open in front of the MPPC
• Source Ru106
• Integration gate 80 ns
• External trigger (Photomultiplier tube)
• Reproducibility of the measurement - 3
• systematic (coupling, positioning etc ...)

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Direct readout with MPPC Most Probable Value of
the mip response spectrum
400 px
1600 px
The green dots correspond to the traditional
wavelength shifter fiber readout. The
performances of the MEPHI SiPMs used are totally
reproduced. THe blue dots correspond to the
direct readout a good light yield is obtained
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The direct readout with MPPC mip collection
efficiency
1600 px
Cut at 3 KHz
400 px
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Direct Readout with MPPC application to
electromagnetic calorimetry
GLD-CAL group, Kobe University
This is the first attempt of using MPPC in the
direct readout configuration in the calorimeter
design. The study of the impact of this
technology in the physics reconstruction is
still in progress.
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The direct readout discussion

• The direct readout looks promising for the
  simplification of the design of the calorimeter
  and the extension of the concept to a large
  scale.
• Still some conceptual problems
• Uniformity of the light response according to the
  impact of the particle in the scintillator
• Montecarlo studies and experiments will test this
  soon
• What is the effect on the performance of the
  calorimeter?
• What is the best position for the coupling?
• The blue sensitive MPPC opened good perspectives
  to the design of calorimeters ready to test new
  photodetectors.

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Application of MPPC in PET motivations and goals

• The calorimeter si just a big PET machine
• The hadron calorimeter has milions of channels
• The hadron calorimeter has a very high
  granularity imaging detector!
• It is only needed to
• Change scintillator (from organic to inorganic)
• Change granularity (from 3x3 cm2 to 1x1 mm2)
• The technology and the needs of the photodetector
  are the same !
• Energy resolution and timing measurements

This study is just at the beginning!
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Application of MPPC in PET setup
2 LSO Crystals of 1mm x 1mm (3mm x3mm) Read out
by 1x1 mm (3x3 mm) Hamamatu MPPC No
amplification needed!!!

QDC
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Application of MPPC in PET energy resolution
PRELIMINARY
PRELIMINARY
3mmx3mm LSO crystal Coupled with a 3mmx3mm MPPC
1mmx1mm LSO crystal Coupled with a 1mmx1mm MPPC
Resolution 14
Resoultion 20
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Application of MPPC in PET timing resolution
Cut at 7 photoelectrons
PRELIMINARY
4 GHz Digital oscilloscope used to calculate the
time difference (50 ps precision) Still the
system needs to be improved with a lower
discrimination.
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Application of MPPC in PETdiscussion

• The application of MPPC in Positron Emission
  Tomography looks promising the blue sensitivity
  of the photodetectors is excellent.
• In DESY we will test different combinations of
  crystals and photodetectors YAP, LYSO... With
  SenSL, new Hamamatsu ....
• The enrgy resolution measurement will be
  continuosly improved in reproducibility and
  stability of the system
• Timing measurement (important also for time of
  flight) is currently beeing improved.

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After the serious conclusions...
The spin off of the technlogical developement
around the new high energy Phyics experiments is
very important... We are dedicating lots of
efforts in order to keep open and fruictful the
interplay between high energy physics and medical
physics. If we will not find the Higgs Boson, at
least, we can tell we were useful for
something...