1. First Results from IceCube Physics Motivation Hardware Overview Deployment First Results Conclusions & Future Plans Spencer Klein, LBNL for the IceCube Collaboration See Paolo Desiati’s AMANDA talk

2. S. Klein, LBNL USA (12) Europe (12) Japan New Zealand Alabama University, USA Bartol Research Institute, Delaware, USA Pennsylvania State University, USA UC Berkeley, USA UC Irvine, USA Clark-Atlanta University, USA Univ. of Maryland, USA Alabama University, USA Bartol Research Institute, Delaware, USA Pennsylvania State University, USA UC Berkeley, USA UC Irvine, USA Clark-Atlanta University, USA Univ. of Maryland, USA IAS, Princeton, USA University of Wisconsin-Madison, USA University of Wisconsin-River Falls, USA LBNL, Berkeley, USA University of Kansas, USA Southern University and A&M College, Baton Rouge, USA IAS, Princeton, USA University of Wisconsin-Madison, USA University of Wisconsin-River Falls, USA LBNL, Berkeley, USA University of Kansas, USA Southern University and A&M College, Baton Rouge, USA Universite Libre de Bruxelles, Belgium Vrije Universiteit Brussel, Belgium Université de Mons-Hainaut, Belgium Universiteit Gent, Belgium Humboldt Universität, Germany Universität Mainz, Germany DESY Zeuthen, Germany Universität Dortmund, Germany Universite Libre de Bruxelles, Belgium Vrije Universiteit Brussel, Belgium Université de Mons-Hainaut, Belgium Universiteit Gent, Belgium Humboldt Universität, Germany Universität Mainz, Germany DESY Zeuthen, Germany Universität Dortmund, Germany Universität Wuppertal, Germany Kalmar university, Sweden, Uppsala university, Sweden Stockholm university, Sweden Imperial College, London, UK Oxford university, UK Utrecht university, Netherlands Universität Wuppertal, Germany Kalmar university, Sweden, Uppsala university, Sweden Stockholm university, Sweden Imperial College, London, UK Oxford university, UK Utrecht university, Netherlands Chiba university, Japan University of Canterbury, Christchurch, NZ Chiba university, Japan University of Canterbury, Christchurch, NZ ANTARCTICA The IceCube Collaboration

3. S. Klein, LBNL Physics Motivation n Search for cosmic-ray accelerators u Protons are bent in galactic magnetic fields  are produced by hadron accelerators u HE (>5*10 13 eV) photons are absorbed by interaction with 3 0 K microwave background photons   --> e + e - n Study the High-Energy Universe u ~100 GeV – 10 19 eV F Cross section & effective area rise with energy, so a single detector can cover a very wide energy range

4. S. Klein, LBNL Physics Topics n Source searches u Active Galactic Nuclei u Supernova remnants u Gamma-Ray Bursts  Calculations predict 1-10 /km 3 /year from many source models n Neutrino physics  Expect 100,000 atmospheric /year u Cross-section measurements F Absorption in earth u Decoherence u Oscillations Searches for supersymmetry, WIMPs, MeV from supernovae, monopoles, Q-balls…. Crab Nebula Active Galactic Nucleus

5. S. Klein, LBNL Detector Requirements n Need 1 km 3 area for a good chance to see signals n Requires a natural material u Ice or water n South Pole Ice has u Long absorption length u Shorter scattering length F Depth dependent u Low dark noise rates Ice model: Scattering vs. wavelength and depth

6. S. Klein, LBNL Lessons from AMANDA AMANDA pioneered  astronomy at the South pole u Deployed first OMs 1993/4 Observed atmospheric  n Deep ice (> 1 km) has good optical qualities n Data transmission to surface nontrivial n Paolo Desiati’s talk will present AMANDA results A muon in AMANDA

7. S. Klein, LBNL n 1 gigaton instrumented volume n 80 strings of 60 digital optical modules u 1450-2450 m deep F 17 m spacing u 125 m hexagonal grid n Each DOM is an autonomous data collection unit n IceTop air shower array u 160 surface water tanks F Each contains 2 DOMs AMANDA String 21 IceCube 1 string + 8 tanks deployed Jan. 2005

8. S. Klein, LBNL , e and  IceCube will distinguish , e and  based on the event characteristics   -->  produce long muon tracks F Good angular resolution, limited energy resolution  Atmospheric  are a significant background to searches for extra-terrestrial Soft energy spectra --> may improve signal to noise ratio by optimizing for higher energy  e --> e produce EM showers F Good energy resolution, poor angular resolution  Above ~10 16 eV   produce ‘double-bang’ events  One shower when the  is created, another when it decays

9. S. Klein, LBNL E µ =6 PeV, 1000 hits E µ =10 TeV, 90 hits Simulated  Events

10. S. Klein, LBNL A e would appear as a single shower n.b.  c  =300 m for E  = 6 TeV A simulated multi-Pev  event

11. S. Klein, LBNL Digital Optical Module main board LED flasher board PMT base 25 cm PMT 33 cm Benthosphere Hardware

12. S. Klein, LBNL Analog Front-End n Want to measure arrival time of every photon n 2 waveform digitizer systems u 200-700 Megasamples/s, 10-bit F switched capacitor array F 3 parallel digitizers give 14 bits of dynamic range F 128 samples --> 400 nsec range F Dual chips to minimize dead-time u 40 Megasamples/s, 10-bit ADC  256 samples --> 6.4  s range n Self-triggered u Also, ‘local-coincidence’ circuitry looks for hits in nearby modules An ATWD waveform Time bin (3.3 ns)

13. S. Klein, LBNL DOM Readout n Each DOM is a ‘mini-satellite’ u FGPA + ARM7 CPU for control, data compression… n Packetized data is sent to surface n Baseline data transmission u waveforms for local coincidence data F Rate ~ 15-30 Hz u timing and charge info for isolated hits F Rate ~ 700 Hz n ‘Rapcal’ timing calibration maintains clock calibration to < 2 nsec A ‘Main Board’

14. S. Klein, LBNL Surface DAQ n Trigger based on multiplicity & topology (in a sliding time window) n Selected data saved to tape n High-priority data sent north over a satellite link n GPS clock for overall timing

15. S. Klein, LBNL Amundsen-Scott South Pole station South Pole Dome (old station ) “Summer camp” road to work IceCube Skiway http://icecube.wisc.edu AMANDA

16. S. Klein, LBNL The drilling site in January, 2005 Hot-water drilling Hose reel Drill tower IceTop tanks Hot water generator

17. S. Klein, LBNL The 5 MW water heater for the hot water drill (car-wash technology) Hose Reel

18. S. Klein, LBNL Each 2 m dia. IceTop tank contains two DOMs. An IceTop tank  signals from IceTop DOMs

19. S. Klein, LBNL Schedule & Logistics n Can work December --> mid-February n Logistics are a huge concern u Freight, power, … are expensive! u Weather is always a factor The new South-Pole station

20. S. Klein, LBNL 27.1, 10:08: Reached maximum depth of 2517 m 28.1, 7:00: preparations for string installation start 9:15: Started installation of the first DOM 22:36: last DOM installed 12 min/DOM 22:48: Start drop 29.1, 1:31: String secured at depth of 2450.80 20:40: First communication to DOM IceCube’s First String: January 28, 2005

21. S. Klein, LBNL 2 high-multiplicity muon events Time Residual (ns) Depth (m)

22. S. Klein, LBNL First Results from String 21 Time calibration Muon reconstruction Timing verification with muons Timing and Energy measurement with LED flashers Coincidence events  IceCube - IceTop

23. S. Klein, LBNL Time Calibration for 76 DOMs Time IceTop In-ice DOMs IceTop

24. S. Klein, LBNL Muon and Flasher Reconstruction n Observe Cherenkov radiation from charged particle tracks n Muons produce ~ km long tracks u + hadronic shower at interaction point n EM cascades produce ~ point sources  LED flashers are a surrogate for e n Reconstruct both with maximum likelihood techniques u Use arrival times of all photons, as determined from waveform information ~10m-long cascades, e  neutral current

25. S. Klein, LBNL Muon zenith angle distribution

26. S. Klein, LBNL Timing studies with muons The random and systematic time offsets from one DOM to the next are small, ≤ +/- 3ns Residual Timing (ns) Scattering  (1/m)

27. S. Klein, LBNL A flasher event Equivalent to ~ 60 TeV e Flasher Color --> arrival time Circle size --> Amplitude

28. S. Klein, LBNL Timing resolution from flashers 1.74 ns rms All 60 DOMs { Photon arrival time difference between DOM45 & 46

29. S. Klein, LBNL Energy Measurement for flashers n Reconstruct energy of flash for each flashing DOM, using known position n Variation due to u Ice models u LED intensity u Detector Response.. n Good agreement across entire string All LEDs Side LEDs 45 0 LEDs ~1/3 Intensity

30. S. Klein, LBNL IceTop and in-ice coincidences Some of the difference is due to shower curvature

31. S. Klein, LBNL Conclusions & Outlook IceCube will explore the high-energy sky. u With a 1 km 3 effective area, IceCube has the power to observe extra-terrestrial neutrinos. n We deployed our first string in January, 2005. u 76 out of 76 DOMs are working well. u Timing resolution is < 2 nsec n Next austral summer, we will deploy 8-12 more strings. u Largest neutrino observatory in the world. n By 2010, we will have instrumented ~ 1 km 3.

32. S. Klein, LBNL Extras/Backup n IceCube reviewers – read no farther

33. S. Klein, LBNL 10” PMT Hamatsu- 70

34. S. Klein, LBNL Muon Angular Resolution Waveform information not used. Will improve resolution for high energies !

35. S. Klein, LBNL Timing verification with light-flashers Photons going up Photons going down 47