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

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]

DOMcalibrator [Cécile Roucelle] : icecube/200709001

Dual t droop correction

General case

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

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

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

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

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

Relative DOM efficiency ongoing…

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 ( )

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]

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.

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

Dust logging in the coming season

Standard Candle Basics Standard Candle I Standard Candle Basics ~4ns @337nm Full intensity: (4.0±0.4)×1012 /pulse 40” N2 laser 8”

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

Standard Candle I: ATWD waveforms on str39 ATWD waveform of str39 DOM10 DOM11 DOM13 DOM15 DOM16 DOM18 DOM19 DOM20 DOM21 DOM25 DOM28 DOM30 MC Real

Standard Candle I: ATWD waveforms on str40 ATWD waveform of str40 DOM10 DOM11 DOM13 DOM15 DOM16 DOM17 DOM18 DOM25 DOM26 DOM28 DOM29 DOM30 MC Real

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

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

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% 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) Milestone

Standard Candle I: 22-string data run 109337 run 109338 100% 50% 30% 10% 5%

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

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

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: 120

Standard Candles Standard Candle II deploy next season 57 Standard Candle II deploy next season pointing downward 63 64 55

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

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

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

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

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…

Pressure vessel <2” I.D. Biaxial tiltmeter for constraining shear @ ~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: -40 to 85 °C Pressure vessel <2” I.D. (TBD)