Quartz Plate Simulation Status

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Quartz Plate Simulation Status

• F. Duru, U. Akgun, A.S. Ayan, J. Olson, Y. Onel
• The University of Iowa

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Quartz Plate Simulation Studies

• Version of the simulation as of October 15,
  2005
• GEANT 4.7.1
• WLS Fiber (Bicron 91a) embedded in the Quartz
  Plate
• Counts Cerenkov photons reaching the
  PhotoMultiplierTube

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Quartz Plate Simulation Studies
Iron absorber
Quartz Plate
WLS fiber
PMT
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An example event of detected photons with Fe
absorber in front

• Quartz Plate is wrapped with reflecting material
  of 95 efficiency.
• Currently UVA, UVB regions are included.
  (gt280nm)
• Cerenkov Photons are shown in GREEN.
• Photons emitted by WLS process are shown in RED.
• The WLS-fiber is visible by the wls (red) photons
  traveling in it.

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Simulation Geometry

• 10 x 10x 0.2 cm Quartz plate
• 0.35/0.30 mm radius clad/core wls fiber
• Counting the photons (wls)
• reaching the PMT
• PMT photo-cathode detection.

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Simulation Geometries
O-shape wls
S-shape wls
Y-shape wls
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Simulated WLS (Bicron 91a) Fiber
We simulated Bicron 91a WLS fiber. This can , of
course, be changed.
The wavelength distribution of generated Cerenkov
and WLShifted photons shown.
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Surface Scan O-Shape

• Scans made with 4 GeV electron beam.
• At every 5 mm in x and y.
• 1000 events for each (x,y) pair.

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Surface Scan Y-Shape
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Surface Scan S-Shape
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Photon Arrival(to PMT) Times
S-shape mean2.9 ns rms 1.1 ns
O-shape mean4.1ns rms 3.4 ns
Y-shape mean2.8 ns rms 2.3 ns
All wls shapes have a mean lt 4 ns photon arrival
time.
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Light Collection Non-Uniformity O-shape
Assume (0 cm,0cm)100 Min 14
Max 614 Ave 127
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Light Collection Non-Uniformity S-shape
Assume (0 cm, 0cm)100 Min 48
Max 253 Ave 80
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Light Collection Non-Uniformity Y-shape
Assume (0 cm,0 cm) 100 Min 21
Max 170 Ave 43
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Light Collection Efficiencies
S/O
Y/O
Both Y- and S- have better light collection
efficiencies than O-shape.
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Light Collection Efficiency Comparison
Light collection efficiency ratios calculated as
the ratio of total number detected
photons by PMT during surface scans for each
fiber geometry O S Y 1 9.9 11.4
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Conclusions

• Y-shape has the highest light yield compared to
• S- and O-geometries
• (O S Y 1 9.9 11.4)
• S-shape has the best surface uniformity on ligth
  collection
• O-shape Max/Min 614/14 44, RMS/Mean0.62
• S-shape Max/Min 253/48 5, RMS/Mean0.36
• Y-shape Max/Min 170/21 8, RMS/Mean0.52