Jonathan Eisch University of Wisconsin River Falls

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Jonathan EischUniversity of WisconsinRiver Falls

• Testing and Calibration of a Water Cherenkov
  Detector

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Why a Water Cherenkov Detector?

• IceTop, companion to IceCube
• Calibration of IceCube
• Cosmic ray air shower detector
• Consists of 80 pairs of 1000 gallon tanks of ice.
• Large individual detector area with readily
  available medium.

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How the detector array works.
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Experiment Objectives

• Refine trigger logic and settings.
• Signal magnitude and shape for varied tank
  parameters (medium volume, PMT position)
• Signal characteristics for various particle paths
  through tank (corner clippers, short paths, long
  paths).

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Design Parameters

• Use a commercially available tank (to reduce
  costs)
• Easily vary water depth
• Position PMTs independently in two dimensions.
• Space for muon telescope around tank
• Maintain light-tightness during parameter changes.

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How our detector works
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Triggering

• Muon telescope (scintillators above and below
  tank) uses for triggering.
• Shower-cancel scintillator ensures single muon
  signals.

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A triggering scintillator
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The Tank
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PMTs
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Our Equipment

• 1.8m diameter by 1.2m tall polyethylene tank with
  black polypropylene and white Tyvek liners.
• 2x 10 Hamamatsu PMTs (icecube)
• 1x 2 SPASE PMT
• LeCroy WaveRunner-2 and WavePro 7000 digital
  oscilloscopes.

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Construction

• Black polyethylene is not black!
• Light tightness and configurability.
• Plumbing.
• Moving PMTs.

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Current Setup
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Preliminary Results

• Tank not completely light tight (35mil
  polypropylene not black enough)
• Trigger rate .5 Hertz
• Testing with plastic scintillator medium followed
  predictions with no ringing.

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Acknowledgements

• Dr. Glen Spiczak
• Dr. Jim Madsen
• Dr. Earl Blodgett - SPS Advisor