1. Calibrating the first four IceCube strings Kurt Woschnagg, UCB L3 Detector Characterization IceCube Collaboration Meeting, Bartol, March 2004

2. Objectives for first four strings What we need What we need DFL measurements (gain, angular acceptance) → DB DFL measurements (gain, angular acceptance) → DB Timing (RAPcal, DAQ software) Timing (RAPcal, DAQ software) Charge (on-board LED, DAQ software) Charge (on-board LED, DAQ software) Geometry Geometry Timing/geometry verification (flashers, muons) Timing/geometry verification (flashers, muons) What we want What we want Optical properties below 2100 m Optical properties below 2100 m Dust profile with volcanic ash bands Dust profile with volcanic ash bands Cross-calibration with AMANDA and SPASE Cross-calibration with AMANDA and SPASE Deep temperature profile → ice flow Deep temperature profile → ice flow

3. Calibration devices Flasher boards geometry, timing, vertex, energy, ice Flasher boards geometry, timing, vertex, energy, ice Dust loggers ice properties Dust loggers ice properties On-board LEDs charge, timing (transit time) On-board LEDs charge, timing (transit time) Pressure sensors geometry, deployment Pressure sensors geometry, deployment Payout, drill, GPS geometry Payout, drill, GPS geometry Laser distance meter well depth (geometry) Laser distance meter well depth (geometry) Thermistors ice properties Thermistors ice properties Acoustic televiewer hole diameter (drilling) Acoustic televiewer hole diameter (drilling) AMANDA, IceTop, SPASE verification, cross-calibration AMANDA, IceTop, SPASE verification, cross-calibration In following years Standard candles (lasers) vertex, energy, (geometry, x-calib) Standard candles (lasers) vertex, energy, (geometry, x-calib)

4. Geometry calibration in 3 stages ► Stage 1 (~days) Combine deployment data: surface survey, drill log, pressure data, payout etc. ► Stage 2 (~weeks → days?) Interstring calibration with flasher data Requires: timing calibration ► Stage 3 (~months → weeks → days?) Muon survey Requires: timing calibration, reconstruction

5. Geometry calibration – Stage 1 Initial geometry from deployment data: GPS survey of surface locations GPS survey of surface locations Pressure sensors Pressure sensors Well depth Well depth Drill log Drill log Cable payout Cable payout + Hole diameter from acoustic televiewer (?) → Absolute OM positions within ~1 m Time scale: days → day?

6. Geometry calibration – Stage 2 Take data with 8-10 flashers on each string Take data with 8-10 flashers on each string Dedicated calibration runs (length: TBD) Dedicated calibration runs (length: TBD) Cross-calibrate with AMANDA OMs and flashers (string 18) Cross-calibrate with AMANDA OMs and flashers (string 18) → Relative string positions within ~0.5 m within ~0.5 m Time scale: weeks → days? Time scale: weeks → days? Global interstring fit to flasher timing data

7. Measuring ice flow with cosmic-ray muons Rigid down to 2000 m Stuck at bedrock Lagging 1.Reconstruct downgoing muon tracks 2.Find location for each OM that minimizes its contribution to the reconstruction likelihood

8. Geometry calibration – Stage 3 Survey with downgoing muons → OM positions within ~0.3 m Time scale: month(s) → weeks → days? Test: finds artificial shifts Development and testing on AMANDA data underway @ UCB (Jeff Allen, Dima)

9. Timing/geometry verification Use reconstructed (downgoing) events Use reconstructed (downgoing) events IceCube muons IceCube muons AMANDA muons AMANDA muons SPASE coincidences SPASE coincidences In-situ light sources In-situ light sources IceCube flashers IceCube flashers AMANDA flashers, lasers AMANDA flashers, lasers Look at Look at time residuals time residuals amplitudes amplitudes reconstructed vertex position reconstructed vertex position

10. Cross-calibrations With AMANDA: AMANDA light sources seen with IceCube strings AMANDA light sources seen with IceCube strings IceCube light sources seen with AMANDA strings IceCube light sources seen with AMANDA strings Separate and common (not in Y1?) reconstruction Separate and common (not in Y1?) reconstruction Matching dust profiles Matching dust profiles With SPASE: Geometry survey – sensitive in depth coordinate (muon tomography sensitive in x,y) With IceTop: Can we do something with 8 tanks?

11. Ice Properties with first four Design, build, deploy first dust logger Design, build, deploy first dust logger Adaptable to IceCube holes? Adaptable to IceCube holes? Verify AMANDA dust profile Verify AMANDA dust profile Ash bands Ash bands Flasher data Flasher data Optical properties from timing fits Optical properties from timing fits Absorption/scattering below 2100 m Absorption/scattering below 2100 m Thermistors Thermistors Firm up deep temperature profile Firm up deep temperature profile Ice flow model Ice flow model