1. Calibrations What’s new in Kurt Woschnagg, UCB
IceCube Collaboration Meeting, Ghent, October 10, 2007

2. Selected Calibration Topics
Waveform Calibration
DOMcalibrator [C. Roucelle]
Linearity/Saturation [S. Seunarine]
Relative DOM efficiency [H. Johannson]
Golden DOMs [M. Inaba]
Ice Properties
Dust logger update: deep ash layer found [R. Bay]
Standard Candle
Waveform analysis [M. Inaba]
Azimuthal asymmetry [J. Kiryluk]
New data (IC22+TWR)
Ice Shear
Interstring flasher data [KW]
Muon tomography [M. Olivo]
Inclinometers [R. Bay]

3. DOMcalibrator
[Cécile Roucelle]
: icecube/

4. Dual t droop correction

5. General case

6. PMT linearity/saturation
[Suruj Seunarine]
Sketch of the method
Measured V
Expected V

7. PMT linearity/saturation
DOMs have different
saturation levels
Will be parameterized
→ DB
→ DOMcalibrator
In-situ flasher data

8. Relative DOM efficiency
[Henrik Johansson]
Calculate average nphotons seen by a DOM from a
track at distance r (use well-reconstructed tracks)
Fit curve according to theory: exp(a-b·r)
Use <nphotons(r=0)> as measure
of DOM efficiency
Relate individual efficiencies to
mean efficiency

9. Relative DOM efficiency
Two ways to estimate <nphotons>
exp(a-b·r)
nHits from FE
Use track detection probability

10. Relative DOM efficiency
Attempt to decouple ice effects
Use average b, refit a
Grouping by
b, abs, z

11. Relative DOM efficiency
ongoing…

12. Calibration of ROMEO with GDOM Outline
[Kotoyo for Mina Inaba]
Comparison
DOMINANT + ROMEO
Simulation
PMT Calib. Data
Glass+Gel Calib.Data
DOM Calib.data
Challenging :
Large PhotoCathode area … Difficult to do overall ABSOLUTE calibration
- Combine RELATIVE 2D measurement small-area ABSOLUTE efficiency measurement ( )

13. Glass + Gel : Acceptance simulation New transmittance and DOMINANT
Outline
Transmittance of glass/gel is updated
Gel : available for all DOMS ! :)
Glass : still small sample(less than 10), need continuous monitoring
New
Acceptance
Photon Acceptance
Old
DOMINANT Simulation
Injection angle : 0deg (off-axis)
Beam size : 8mm
Beam location : center of PMT
Parallel beam
Updated DOMINANT(Geant4)
New glass/gel transmit.
Harness, MB, FB, HV installed
Fresnel reflection ON
Wavelength [nm]

14. Outline Golden DOM calibration Summary
We averaged available PMT calibration data
New Glass/Gel transmittance table is applied to DOMINANT simulation
The averaged absolute calibration of GDOM and Romeo + DOMINANT simulation with averaged calib data shows GOOD agreement over all wavelength range
New Romeo + DOMINANT simulation represents Stoyan’s In Water Angle Acceptance measurement
This plots shows the comparison between DOM measurements and the PMT measurement+glass-gel simulation.
The histogram is the expected efficiency which is provided by the simulation explained in the previous slide.
The red points are the value of DOM measurements.
The difference between simulation and data was 12% at 337nm at first, and then
We found that a shift of -3 nm of the penetration curve of a glass and a gel make the difference 0.5%.
You can see that data and simulation agrees well over the wavelengths.

15. Dust logger update [Ryan Bay]
First ash layer identified in instrumented volume:
Corresponds to known 92,000 year old ash layer in Dome C core

16. Dust logging in the coming season

17. Standard Candle Basics
Standard Candle I
Standard Candle Basics
Full intensity:
(4.0±0.4)×1012 /pulse
40”
N2 laser 8”

18. Standard Candle I: waveform analysis
[Aya for Mina Inaba]
ATWD based total estimated Npe
100% ?
First guess center of brightness
COBy [m]
COBx [m]

19. Standard Candle I: ATWD waveforms on str39
ATWD waveform of str39
DOM DOM DOM DOM15
DOM DOM DOM DOM20
DOM DOM DOM DOM30 MC
Real

20. Standard Candle I: ATWD waveforms on str40
ATWD waveform of str40
DOM DOM DOM DOM15
DOM DOM DOM DOM25
DOM DOM DOM DOM30 MC
Real

21. Standard Candle I: waveform analysis
[Aya for Mina Inaba]
Charge Ratio MC/Real
1690m
1910m
1680m
1920m SC

22. Standard Candle I: azimuthal asymmetry
[Joanna Kiryluk]
Standard Candle data
1.30 [rad]
4.34 [rad]
2.35 [rad]
3.45 [rad] SC
DOM Number

23. Standard Candle I: 22-string data
[Taboada/Filimonov]
Data taken on September 18, 2007
pDAQ IC22+TWR default configuration
PnF running
7 filter wheel settings: 0.5%-100%
1Hz, 2000 pulses/setting
80 GBytes of raw data → SC filtering needed
Filtered data now in Data Warehouse:
/data/exp/IceCube/2007/internal-system/
DebugData/1004/DebugData_SCData_Oct03.tar.gz
First pDAQ calibration data taken without detector downtime (as envisioned in the PDD)
Milestone

24. Standard Candle I: 22-string data
run
run
100%
50%
30%
10% 5%

25. Standard Candle I: 22-string data
5% setting, ~120 DOMs
100% setting, ~250 DOMs
[AMANDA hits not shown]

26. How to take future Standard Candle data
[I. Taboada]
Write a Standard Candle trigger
Base trigger on multiplicity, topology, timing
Create a pDAQ configuration that enables this trigger
Otherwise configuration identical to default
Add a PnF filter that runs all the time to select events with a SC trigger
No downtime and automatic filtering of SC data

27. Standard Candle II To be deployed on string 55 (3rd of the season)
Between DOMs 42 and 43
λprop (2150 m) ~38 m (SC-II)
λprop (1813 m) ~22 m (SC-I)
Pointing down (SC-I points up)
About 10 times brighter than SC-I
Filter wheel dynamic range:
SC-II: 1500
SC-I:

28. Standard Candles Standard Candle II deploy next season57
Standard Candle II
deploy next season
pointing downward

29. Three experimental approaches: 1. Using the three deep AMANDA strings
Ice Flow and Shear
flow model
Three experimental approaches:
1. Using the three deep AMANDA strings
2. Muon tomography
3. Inclinometers

30. Using the deep AMANDA strings
● 48/57/58: recently deployed = ~vertical
● 11/12/13: in the ice for >9 years

31. Pilot Runs 9/17
Dawn Williams
Andreas Gross
~1700 m
~2000 m
~2300 m

32. What resolution can we achieve?
Zoom in:
1 bin = 5 ns ≈ 1 m
~2300 m

33. muon tomography [Martino Olivo] Reconstruct tracks (include the DOM)
Move DOM around (virtually),
keep tracks stationary
See how reco likelihood
changes → Pandel function

34. muon tomography

35. muon tomography
Under development…

36. Pressure vessel <2” I.D.
Biaxial tiltmeter for constraining ~2430 m
(on 3-4 strings 2007/08)
[Ryan Bay]
Special
Devices
breakout y x
~0.5°/year 3
strings
meters per year
Angular resolution: 0.01°
Angular range: +/- 25°
Operating temp: to 85 °C
Pressure vessel <2” I.D.
(TBD)