flasher asymmetry and hole ice propertiesglacier.lbl.gov/icecube/flasherworkshop/rutledge.pdf ·...
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Flasher Asymmetry and Hole Ice Properties
Doug RutledgePenn State University
Doug Rutledge Berkeley Tuesday July 25 2005 1
Flasher Data
Set ATWD Channel(s).Set FADCRecord Data.
Flash LEDs. Do Not record data.
● 2 Data Sets– Dom 23 (Lemur)
● Earlier in the year● Mini String (~10 DOMs) ● Full ATWD Readout
– Dom 52 (Nitrogen)● More Doms than mini string● Bottom of the String● 32 Samples in each ATWD
Channel● Only the first ATWD Channel
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Flasher Asymmetry: Run 428
Dom 22
Dom 21
Dom 20
Dom 19
Dom 24 Dom 25
Dom 26Dom 27 Dom 28
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Waveforms
Dom 24
Dom 22
ATWD Channel0
ATWD Channel 1
ATWD Channel 2
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Waveforms II
Dom 25
ATWD Channel 0
ATWD Channel 1
ATWD Channel 2
Dom 21
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Flasher Asymmetry II: Run 2993
Dom 54
Dom 55
Dom 45
Dom 46
Dom 56
Dom 51 Dom 50 Dom 49
Dom 48
Dom 47
Dom 53
Saturation
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Waveforms III
No ATWD Channel 1
ATWD Channel 0
No ATWD Channel 2
Dom 49
Dom 55
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Waveforms IV
ATWD Channel 0
No ATWD Channel 1
No ATWD Channel 2
Dom 48
Dom 56
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Photonics Studies I:Geometry
Michelangelo's Photonics Special features
hole radius: 0.3 m
flasher wavelength: 405 nm
Hole Ice Scattering Length: variable
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Photonics w/ Hole
Ice
http://amanda.berkeley.edu/~mdagost/photonics/
Plots courtesy of Michelangelo D'Agostino
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6 horizontal flashersScattering in & out of the hole
Photon Flux I:Hole Ice scattering length =
50m
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Flux, in arbitrary units
Photon Flux II: Hole Ice scattering length =
1cm
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Flux, in arbitrary units
Photon Flux comparison
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So why is there no difference?
● RHole
– RDom
≈ 10 cm▬ Few sacttering events in the hole
New Flasher data ● Data w/ just horizontal
flashers● Data w/ just angled
flashers● Full ATWD Readout● Wish List:
– OM in the dust Layer– Full ATWD Readout
● 128 Samples● All three channels
– Flasher data for each DOM– A lot of these conditions are
met with new data
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Further Photonics Studies
● New Photonics tables– Only horizontal Leds– Only angled Leds
● Simulate out to other strings
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Further Studies
● Detect flashers with AMANDA?– Probably not– Try it with new
strings? (next year)● Waveform studies
– Length of waveform tail
● In Principle, depends on scattering length
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Conclusions
● Hole Ice scattering length has little effect– Detector is insensitive to dramatic changes
● Up/Down asymmetry– New flasher data
● Test the effects of angled vs horizontal LEDs● Make Q Vs D plots
– Use channel switching– More participating Doms
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This is why it is called a “mini-string”
Hole size studies I:Hole Radius = 1.5m
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Hole size studies II:Hole radius = 5.0m
Big Difference!
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Ratio of Qabove
to Qbelow
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Dust Layer