Highresolution, fast and radiationhard silicon tracking station

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High-resolution, fast and radiation-hard silicon
tracking station
STS working group

• CBM collaboration meeting March 2005

2
Status STS

• Conceptual design (CDR)
• First round of simulations (TSR)
• ITS with 3 pixel planes
• SIT with 4 equidistant planes, strip technology
  through out
• Design iteration (partly in TSR)
• Optimize configuration
• Include HitProducers in simulation
• Physics performance studies for different physics
  cases
• Final design (TDP 2006?!)
• Senors/FE chip, module, supportcooling, readout
• Technological feasibility (RD)
• Full performance simulation

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Facts after 2nd round of simulations
Depends strongly on the physics case. Alternative
configurations for different observables possible.
Beam pipe of 1 cm Ø
First 3 stations (ITS) inside the vacuum!
Possibly shielded against good beam vacuum by a
foil.
Fluence above 1016
Is this the last word
?
Pixel
Strip
Only strip sensors for stations 4 to 7 (SIT) if
micro2 strips are used close to the beam!
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Challenging tasks of the tracking station (I)

• Micro vertex reconstruction (main task of the
  ITS)
• Secondary vertex reconstruction better 50mm
  (z-coordinate)
• Extremely high track density

D0?K-p
Both high resolution and a respectively low
material budget are needed.
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D0?K-p
Material budget / plane
I. Vassiliev
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Challenging tasks of the tracking station (II)

• Background rejection in low mass dielectron
  spectroscopy
• Reconstruction of "incomplete" tracks
• Needs probably much more redundancy

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d-electrons are a huge concern

• Yield in 1st station 5/gold ion passing the (1)
  target
• 5000 at frame rates of 10 ms and 109 ions/s !?

8
Possible configuration (B-TeV inspired)

• Outer section of plane 3 outside the vacuum!
• Highest granularity not needed there
• Allows using thin vacuum window
• Detectors can be moved in two halfs.
• Remove sensors from beam area during focusing
• Only two different module geometries
• Optional for MAPS or Hybrids

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Generic designs for simulation

• MAPS-like
• Radiation hardness
• Read-out speed

• Hybrid-like
• Material budget
• Resolution

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MAPS material budget a first assessment by
Michael Deveaux

• Stacking of sensors due to inactive read-out area
• Design VELO (LHCb) inspired

0.29
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MAPS RD

• Dense program of chip submission in 2005
• MIMOSA 9 ? factor 2 lower signal than expected
• MIMOSA 10 ? MIMOSTAR1 first prototype for STAR
  IT
• MIMOSA 11 ? Various sensor geometries for
  studying aspects of radiation tolerance
• MIMOSA 12 ? Multiple charge storage
  on-pixel, aspects of capacitor performance
• MIMOSA 13 ? Current readout faster, better
  noise immunity
• Transfer of one test station to Frankfurt
• Support RD efforts starting with MIMOSA11
• Aspects of cryogenic operation

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Assessment for GIGATRACKER
http//na48.web.cern.ch/NA48/NA48-3/groups/gigatra
cker/

• NA48 CERN-SPSC-2004-029 (K?pnn)
• Concept (only small area needs to be covered)
• High rate 40 MHz / cm2
• 100 ps time resolution
• Fluence 4.5 1014 cm2 (12 Mrad)
• 0.13 mm envisaged

x/X0 lt 0.6
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STS working packages
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Design optimization
Mainframe
STS group
Tracking groups
Algorithms
Digitizers
MAPS HitProducer (Michael)
Design Optimization
Strip HitProducer(Valeri)
Final configuration
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Towards a Design Proposal