What’s new inCalibrations

Kurt Woschnagg, UCB

IceCube Collaboration Meeting, Ghent, October 10, 2007

● 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]

Selected Calibration Topics

DOMcalibrator [Cécile Roucelle]

: icecube/200709001

Dual droop correction

General case

PMT linearity/saturation[Suruj Seunarine]

Expected V

Measured VSketch of the method

PMT linearity/saturation

DOMs have differentsaturation levels

Will be parameterized→ DB→ DOMcalibrator

In-situ flasher data

• 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

Relative DOM efficiency[Henrik Johansson]

Relative DOM efficiency

Two ways to estimate <nphotons>

nHits from FE

Use track detection probability

exp(a-b·r)

Attempt to decouple ice effects

Relative DOM efficiency

Use average b, refit a

Grouping

byb, abs, z

Relative DOM efficiency

ongoing…

DOMINANT+

ROMEOSimulation DOM Calib.data

PMT Calib. DataGlass+Gel Calib.Data

Comparison

OutlineCalibration of ROMEO with GDOM

Challenging : Large PhotoCathode area … Difficult to do overall ABSOLUTE calibration - Combine RELATIVE 2D measurement + small-area ABSOLUTE efficiency measurement ( )

[Kotoyo for Mina Inaba]

OutlineGlass + Gel : Acceptance simulationNew transmittance and DOMINANT

Transmittance of glass/gel is updated - Gel : available for all DOMS ! :)- Glass : still small sample(less than 10), need continuous monitoring

Wavelength [nm]

Acc

epta

nce

Old

New

Updated DOMINANT(Geant4)- New glass/gel transmit.- Harness, MB, FB, HV installed- Fresnel reflection ON

DOMINANT SimulationInjection angle : 0deg (off-axis)Beam size : 8mmBeam location : center of PMTParallel beam

Pho

ton

Acc

epta

nce

OutlineGolden 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

Dust logger updateDust logger update

Corresponds to known 92,000 year old ash layer in Dome C core

First ash layer identified in instrumented volume:[Ryan Bay]

Dust logging in the coming seasonDust logging in the coming season

40”

8”

N2 laser

~4ns @337nm

Full intensity: (4.0±0.4)×1012 /pulse

Standard Candle BasicsStandard Candle I

Standard Candle I: waveform analysis

[Aya for Mina Inaba]

First guess center of brightness

COBx [m]

CO

By

[m]

ATWD based total estimated Npe

100%

?

ATWD waveform of str39

DOM10 DOM11 DOM13 DOM15

DOM16 DOM18 DOM19 DOM20

DOM21 DOM25 DOM28 DOM30

MC

Real

Standard Candle I: ATWD waveforms on str39

ATWD waveform of str40

DOM10 DOM11 DOM13 DOM15

DOM16 DOM17 DOM18 DOM25

DOM26 DOM28 DOM29 DOM30

MC

Real

Standard Candle I: ATWD waveforms on str40

Standard Candle I: waveform analysis

[Aya for Mina Inaba]

SC

1690m 1910m

1680m 1920m

Charge Ratio MC/Real

DOM NumberSC

1.30 [rad]

4.34 [rad]

2.35 [rad]

3.45 [rad]

Standard Candle I: azimuthal asymmetry

Standard Candle data [Joanna Kiryluk]

Data taken on September 18, 2007• pDAQ IC22+TWR default configuration• PnF running• 7 filter wheel settings: 0.5%-100% • SC @ 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)

Standard Candle I: 22-string data

Milestone

[Taboada/Filimonov]

Standard Candle I: 22-string data

100%50%

30%

10%5%

run 109337 run 109338

Standard Candle I: 22-string data

5% setting, ~120 DOMs 100% setting, ~250 DOMs

[AMANDA hits not shown]

• 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 dataNo downtime and automatic filtering of SC data

How to take future Standard Candle data

[I. Taboada]

• 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: 120

Standard Candle II

57 63 64 55

Standard Candle II • deploy next season• pointing downward

Standard Candles

http://wiki.icecube.wisc.edu/index.php/Ice_shear_measurement

flow model

Ice Flow and Shear

Three experimental approaches:1. Using the three deep AMANDA strings2. Muon tomography3. Inclinometers

● 48/57/58: recently deployed = ~vertical● 11/12/13: in the ice for >9 years

Using the deep AMANDA strings

~2000 m

~2300 m

~1700 m

Pilot Runs 9/17Dawn WilliamsAndreas Gross

~2300 mZoom in:

1 bin = 5 ns ≈ 1 m

What resolution can we achieve?

muon tomography[Martino Olivo]

Reconstruct tracks (include the DOM)

Move DOM around (virtually),keep tracks stationary

See how reco likelihood changes → Pandel function

muon tomography

muon tomography

Under development…

x

y

SpecialDevicesbreakout

Angular resolution: 0.01°Angular range: +/- 25°Operating temp: -40 to 85 °C

meters per year

Biaxial tiltmeter for constraining shear @ ~2430 m(on 3-4 strings 2007/08)

Pressure vessel <2” I.D.Pressure vessel <2” I.D.(TBD)(TBD)

3strings

~0.5°/year

[Ryan Bay]