Upstream Photon Veto

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Upstream Photon Veto
GlueX Apparatus
UPV
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Need for Hermitic Detection
Simulation studies show for reactions with
photons emanating from the baryon decay vertex
that approximately 10 of the photons miss
detection by either the barrel calorimeter or the
lead glass detector.
Upstream Hole
GlueX Note 36
These gammas go undetected by escaping out the
upstream hole.
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UPV
A Soft-Iron Scintillator Sandwich Design

• Regain magnetic field- shaping
• Detect photons of energy gt20 MeV
• Multiple photon detection
• Fast detection w/ timing information

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UPV Design
18 layers 1cm thick scintillator 12 layers
0.635cm thick iron (0.36X0) 6 layers 1.270cm
thick iron (0.72X0)
Total 8.91X0
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RD Prototyping for UPV

• Construct Two Competing Veto Prototypes
• Study the feasibility of using iron as a radiator
  instead of lead for low energy measurements
• Instrument to test the building technique
• Build infrastructure in place for future RD w/
  final goal of the construction of the UPV

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Machining Milling
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Polishing Wrapping
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Stacking Prototype 1
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Present State

• Light guides
• UVT strips ready for bending
• Winston cones are being made
• PMTs
• ADIT B51D01
• Bases
• ADIT Model 112-2

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Test DAQ
VME
VME to PC Bridge
Linux DAQ
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Future Plans

• Prototype Module 1
• Completion by end of year
• Prototype Module 2
• Jan-Feb completion
• Testing during spring
• Initial cosmic ray studies
• Possible JLab studies(?)