CLAS12 Silicon vertex Tracker Summary Talk

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CLAS12 Silicon vertex TrackerSummary Talk

• Latifa Elouadrhiri

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outline

• Extension of physics reach
• Design summary
• Simulation results
• Construction details
• Project outlook

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SVT Extends Physics Reach

• Barrel Silicon Tracker (BST)
• Many experiments require charged particle
  detection in central region
• 50 of events have 1 or more charged tracks in
  central region
• Resolution and efficiency well-matched to forward
  detector
• Large extension of kinematic coverage (35 125o)
• Forward Silicon Tracker (FST)
• Improved f resolution especially forward-going
  electrons
• useful for coplanarity cuts
• Excellent vertex resolution (impact parameter
  200 mm)
• enables a strong signal/background enhancement of
  strangeness events augmenting K identification
• May allow efficiency identification of "stub"
  tracks
• useful in establishing "exclusivity" of events

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Design Summary

• Central tracker (35 125o)
• 4 planes (u-v graded stereo) 150 mm pitch
• 1 3 sensors wire-bonded on a rectangular stave
• Butt-jointed polygonal structure
• Forward tracker (5 35o)
• 3 disks (u-v stereo, /- 12o) 150 mm pitch
• 2 sensors wire-bonded onto a trapezoidal stave
• Butt-jointed trapezoidal structure

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Simulation Results

• Track-finding algorithms developed
• stand-alone for BST matching with DC for FVT
• Good missing momentum resolution in central
  region, improved vertex and f-resolution for FVT
• GEANT4-based backgrounds generated
• High efficiency for track reconstruction at the
  design luminosity
• Full simulations, realistic backgrounds
• will perform as required

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Construction Details

• Standard techniques
• 300 mm sensors sized to optimize dicing
• up to 3 sensors wire-bonded on a stave
• only 3 masks central 2 masks forward
• SVX4 chip proven design FSSR2 ?
• unified mechanical design
• heat loads identified cooling being designed

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Project Outlook

• Scope of the BVT and FVT
• well defined, well-known technology,
• moderate risk lack of in-house experience with
  silicon
• strong collaboration in place
• Main performance parameters defined
• verified by RD
• GEANT4 simulation and track reconstruction
• detailed engineering design underway
• ESHQ issues identified
• identified during RD and design phase,
• relevant to detector assembly, installation,
  interface with other CLAS12detectors and
  maintenance
• With these capabilities CLAS12 will be able to
  carry out a world-class experimental program in
  fundamental nuclear physics