Hall B 12 GeV Upgrade System

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Hall B 12 GeV Upgrade System Safety
ReviewProject Overview
Latifa Elouadrhiri Hall B 12 GeV Control Account
Manager
2
CLAS12 Design Parameters
The physics program allows to firmly establish
requirements for the CLAS12 performance in terms
of rate capability, particle ID, and
resolution. (See Burkert Talk)
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Torus and Solenoid Magnets
Reference Design Max. field B5
Tesla Homogeneity ?B/Blt10-4 Main coil 4000
turns Shielding coil 1880 turns Stored energy
25 MJ
Reference Design coils 6 Radial thickness
294mm Width 100mm Stored energy 14MJ
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Procurement Schedule TORUS
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Procurement Schedule Solenoid
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Silicon Vertex tracker

• BST and FST designs can achieve the physics
• specifications
• robust and proven design
• Q coverage BST 35o 125o FST5o 35o
• F coverage 2p
• BST 4 regions (u-v graded stereo 0o 3o)
• FST 3 regions each with u-v stereo strips ( /-
  12o )
• Good segmentation, good resolution
• High efficiency for track reconstruction over all
  f
• Low rate of fake tracks at L1035 cm-2s-1
• Good missing momentum resolution, matched to the
  forward detector
• Proven by a full event simulation and
  reconstruction program

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DC
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High Threshold Cerenkov Counter (HTCC)

• Works in conjunction with CLAS Low
  ThresholdCerenkov Counter and Preshower
  Calorimeter and the CLAS Electromagnetic
  Calorimeter, to provide electron identification
  in full kinematics
• Optical properties defined
• Response to electrons, pions, and background
  particles simulated in detail, and meets
  requirements for high pion rejection
• Operation in magnetic field is used as input for
  the design of the solenoid magnet
• Sensitivity of PMTs to magnetic field addressed
  in RD plan for prototype of multi-layer magnetic
  shield.
• Light-weight mirror construction techniques
  developed to limit impact on 3-momentum
  resolution
• Light readout segmentation allows use in trigger
  decisions

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Pre-Shower Calorimeters (PCAL)

• Provide sufficient granularity and position
  resolution for the separation of photons and p0
  for momentaup to 10 GeV/c
• Add 5 radiation lengths in depth to EC and
  provide full shower and energy containment
• Choose design readout that allows use of low-cost
  extruded scintillator material and low cost PMTs
• Non-projective geometry greatly simplifies
  construction and allows significant cost savings
• Full GEANT simulation to optimize readout
  segmentation

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Central Time of Flight

• CTOF design with R2083, magnetic shield, and bent
  Light Guides will likely achieving the 60 ps
  timing resolution. This is based on a realistic
  prototype, high statistics tests, and MC
  calculations.
• Further RD work that is currently underway may
  allow lt 60 ps.
  
  
  
• The design allows simple integration of other
  PMTs and achieving the desired performance
  independently on other systems.
  
  
  
• Extensive documentation of RD work is
  publically available in Nucl. Inst. Meth. and
  CLAS notes.
  
  
  
  
• Safety considerations and QA processes have been
  defined and are being incorporated in design,
  component construction, assembly.

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Forward Time-of-Flight
12
Design Drawings
DC R2 End Plate Detail
PCAL PMT Header
HTCC Main Assembly
CTOF Fwd light guide support
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Detector Design and Integration

• Design solutions for all detectors are well
  advanced and many are into making detail
  fabrication drawings.
• Integration of detectors and magnets is being
  addressed and magnet specifications being
  written.
• For systems that mount on the magnets, interface
  requirements will be part of specifications for
  both components.
• Installation and maintenance procedures have been
  addressed in detector designs.
• Installation plan shows ample float.
• Safety plan is well developed and special issues
  including onsite assembly and installation have
  been addressed.

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Online DAQ Electronics

• CLAS12 DAQ will meet requirements 10kHz event
  rate, 100MB/s data rate, lt15 dead time
• CLAS12 Trigger System will be able to reliably
  identify electrons and select multi-particle
  events
• CLAS12 Electronics exists or currently under
  development in JLAB
• CLAS12 Online System main components exist and
  will be integrated into Experiment Control System

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Detector Simulation and Event reconstruction

• Full modeling of the CLAS12 Detectors and
  magnetic field in place
• Detail simulation in the presence of
  electromagnetic and hadronic background has been
  performed
• CLAS12 can operate at the design luminosity
• Track reconstruction code based on Kalman Filter
  has been developed for both the forward and
  central detectors
• Derived resolutions satisfies the physics
  requirements
• High tracking efficiency at the design luminosity
  1035cm-2s-1
• Excellent track matching between Drift Chamber
  system and Forward SVT
• Forward SVT provides large improvements on track
  parameters
• 3-10 times better for the vertex, 1.2 -1.9 for f

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Summary

• CLAS12 technical performance parameters are well
  defined
• Burkert talk on physics requirements, and the
  individual system talks
• Construction plans for each system are
  well-developed assembly plans consistent with
  Upgrade and Hall B installation schedule
• Baseline project plan in Cost book and P3e
  schedule
• Summary presented in Elouadrhiri morning talk,
  and Dave kashy for the overall schedule of
  installation and integration
• Detector likely to achieve performance with low
  risk
• Overall Low risk based on
• Cost and schedule estimates well-founded and
  well-documented
• System integration plan within CLAS12 and Hall B
  is well studied and developed
• Details presented in Kashy talk
• ESH aspects of construction and commissioning
  have been incorporated into project plan