BigBite%20Spectrometer%20Equipment

1
BigBite Spectrometer Equipment

• by
• Douglas W. Higinbotham

2
BigBite Family of Experiments

• Threshold Pion Production (Hadron Package)
  Cryo-Target
• Transversity d2 (Electron Package) 3He Target
• Ay (HRS) (e,ed) (Hadron Package) 3He Target

3
BigBite Infrastructure For Transversity

• Magnet Continues To Work Without Issue (one spare
  coil)
• Power Supply Has Had Only Minor Problems
• Problem Tends To Be With Communication
• We Rarely Change Field, So Not Big Issue
• Technicians Have Tried To Fix This
• Extremely Tight Space To Get To 30 Degrees
• New Right Foot Designed and Ordered
• Work On Beam-line Area Needs To Be Done (Folts)
• GEN Field Clamp Extended
• Re-use GEN Side Shielding
• Add Better Internal Shielding (Multi-Experiment
  Problem)

4
BigBite Detectors For Transversity

• Three Full Wire Chambers
• Send Middle Chamber To UVa During March
• Designer Assigned
• Upgrade Chamber Major Item For Review
• Trigger Scintillators
• PreShower Shower Detector
• Several PMTs Marginal (near 2kV) and Few Dead
• Either Buying 60 PMTs or 10 PMTs
• NEW Gas Cherenkov Designed by Brad
• Major Item For Review
• Asked JLab For 60k This FY For This Project

5
Wire-Chamber Electronics

• We have both VME and Fastbus! Though would need
  four more VME units for middle chamber read-out.
• 200 pre-Amp cards and associate equipment in
  production.
• Over 100 have been delivered.
• Rest In The Electronics Groups Queue
• 40 more pre-Amp cards are being ordered.
• 210 needed for three 6 plane chambers (240 total
  order)

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Electronics and Cables

• All experiments will share wirechamber
  electronics.
• The pi0 (e,ed) experiments will be using
  mostly their own NIM/CAMAC electronics.
• d2 and Transversity NIM/CAMAC electronics
  converging, BUT not yet finalized.
• Brad is adding Cherenkov to trigger setup
• Must be done in the coming week!
• Albert Coming To Help Supervise Construction

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Test Lab

• All BigBite experiments share the test lab space.
• Douglas Manages The Space
• Eugene Is Area Safety Warden
• Bertha Power Supply (440V) Needs To Be Moved To
  Test Lab
• Single Source Of Power
• Solves Outlet Problem and Hopefully Grounding
  Problems
• Safety Is Important
• Some Items Need Safety Procedures
• Procedures Needs Many Signatures
• Once GEP III Leaves, We Will Get Some Space Back
• BUT, It Will Continue To Be Very Crowded
• Work Safely!