Status of 1.5.3 Detector Characterization a.k.a. Calibration & Monitoring

1. Status of1.5.3 Detector Characterizationa.k.a. Calibration & Monitoring • Project Year 2 objectives (→ Mar ‘04) 1. Calibration plan (first draft in March ‘03 – still circulating…) 2. Define contents of calibration DB 3. Define algorithms 4. Monitoring interface for TestDAQ 5. Monitoring plan (new L4 for monitoring: Rodin Porrata) • Manpower 1 FTE (UCB) + 0.5 FTE (UW) + 0.2 FTE (UD) + δ Kurt Woschnagg, UC Berkeley

2. Calibration Tasks • Low-level calibrations: • Timing 7 ns • Geometry 1 m • Charge, OM gain (lab, ice) • Angular OM acceptance (lab) • Optical ice properties • High-level calibrations: • Energy (cascades) • Vertex resolution • Pointing accuracy and angular resolution • DOM lab calibrations not included here

3. Timing calibration Automatic, part of normal DAQ ops 1. Every waveform time-stamped (coarse, fine) locally in DOM 2. Clock calibration (RAPcal) to relate local times to global (master) time 3. PMT transit time measurement (in lab, in-situ with onboard LED) Testing (post-deployment): - with flasher data - with muons (req. reconstruction) Development and testing underway @LBL

4. Calibration devices • Standard candles (lasers) vertex, energy • Flasher boards geometry, timing, vertex, energy, ice • Dust loggers ice properties • On-board LEDs charge, timing (transit time) • Pressure sensors geometry, deployment • Payout, drill, GPS geometry • Acoustic televiewer drilling So far: physics requirements, cable issues

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

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

7. Geometry calibration – Stage 2 Global interstring fit to flasher timing data → Relative string positions within ~0.5 m Time scale: weeks → days? Does it work in IceCube?

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

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

10. Optical properties of ice From in-situ light sources in AMANDA we get (after some analysis): So what is left to do…

11. Are the dust bands horizontal over km-scale? 2. What happens below 2100 m? 3. Can we measure hole ice prop.? Optical properties in IceCube

12. Calibration hardwareFlasher boards • Requirements document (ERD) finalized • Each board has 12 LEDs (405 nm) 6 horizontal for geometry 6 at ~45° for cascade simulation All 12 can be fired independently Adjustable light output • Cascade energies up to 10 TeV (at least)

13. Calibration hardwareDust loggers Conceptual design stage, but: • Experience at UCB • Proven method Optimal placement: in IceCube corners and at AMANDA center Deploy first season?

14. Record of Northern climate variations at GISP2(Greenland Ice Sheet Project, 3054 meters) A dust logger in action Ryan Bay, UCB Dust logger data Dust in ice core Temperature record from ice core

15. DOM gain (charge) calibration Relate measured charge to number of photoelectrons • In lab (pre-deployment): measured for all DOMs → database - SPE peak - linearity - dynamic range - saturation - dependence on HV, temperature • In situ (post-deployment): on-board LED, min-bias muon data - SPE peak - linearity? saturation?

16. Calibration hardwareOn-board LEDs Hardware: Separate UV LED on DOM main board Purpose: Charge calibration: SPE peak Timing calibration: PMT transit time Work in progress (@LBL): Light output Pulse width Optical coupling Placement

17. Cascade energy calibration ~105 photons/GeV In-situ light sources: • Flashers; up to 10 TeV • Lasers; 1 TeV and up Standard candles: absolute calibration in lab Realistic cascade simulation (light distribution, timing) • Overlay events to reach higher energies - saturation (database with lab measurements) - software

18. Getting ready for the first strings The first IceCube string is deployed in Dec ’04 …then what? Mainly calibrations in ’05 • Timing calibration • Reconstruction • Deployment daq AMANDA/IceCube cross calibrations: - Common reconstruction - Coordinate system

19. Dependencies by WBS element • Reconstruction • Deployment • DAQ • AMANDA-IceCube integration • Software • Simulation • In-ice devices (in-situ light sources) • Monitoring, database, … help!