1. 1. Introduction 2. IceCube Detector 3. Neutrino Detection Principles 4. Status of the Construction and Performance 5. Summary IceCube neutrino telescope@SouthPole - a new window on the universe Joanna Kiryluk LBNL/UC Berkeley

2. UHE Cosmic Rays GZK cutoff Greisen, Zatsepin And Kuzmin (1966) What’s the origin of Cosmic Rays with E up to 10 20 eV ? The puzzle unresolved almost a century after CR discovery ? SNR

3. - do not point back to the source  protons: directions scrambled by magnetic fields   -rays : straight-line propagation Multi-Messenger Astronomy Where do UHE cosmic rays come from? protons,  -rays & neutrinos as probes of the high-energy Universe

7. - do not point back to the source but reprocessed in the sources (difficult to prove that they are associate with CR); extragalactic backgrounds absorb E  >TeV Multi-Messenger Astronomy Where do UHE cosmic rays come from? protons,  -rays & neutrinos as probes of the high-energy Universe  protons: directions scrambled by magnetic fields   -rays : straight-line propagation  Neutrinos:  Neutrinos: straight-line propagation, unabsorbed, but difficult to detect

8. Expected n flux from galactic point sources, example SNR: RXJ 1713-3946 Christian Stegmann et al., J.Phys.Conf.Serv.60 (2007) 243

9. cosmic rays interact with the microwave background cosmic rays disappear, neutrinos appear Neutrinos from GZK interactions Expect ~ 1 event per km2 per year GZK neutrinos - very low but guaranteed flux (GZK CRs exist!)

10. (Ultra-) high-energy neutrino detectors Neutrino telescopes: Primarily aimed at > TeV , e.g. IceCube /AMANDA, Antares … Also sensitive to PeV, EeV, but limited area New directions with effort to detect: Giant air showers detectors sensitive to ~EeV  e.g. Auger Radio detection - threshold in EeV range, e.g. Anita Extraterrestrial neutrinos - discovery potential! The only confirmed extraterrestrial low energy neutrino sources detected so far are the Sun and the supernova SN1987A

11. USA: Bartol Research Institute, Delaware Pennsylvania State University UC Berkeley UC Irvine Clark-Atlanta University University of Maryland IAS, Princeton University of Wisconsin-Madison University of Wisconsin-River Falls Lawrence Berkeley National Lab. University of Kansas Southern University and A&M College, Baton Rouge University of Alaska, Anchorage Sweden: Uppsala Universitet Stockholm Universitet UK: Imperial College, London Oxford University Netherlands: Utrecht University Belgium: Université Libre de Bruxelles Vrije Universiteit Brussel Universiteit Gent Université de Mons-Hainaut Germany: Universität Mainz DESY-Zeuthen Universität Dortmund Universität Wuppertal Universität Berlin MPI Heidelberg RWTH Aachen Japan: Chiba university New Zealand: University of Canterbury THE ICECUBE COLLABORATION 33 institutions, ~250 members http://icecube.wisc.edu ANTARCTICA Amundsen-Scott Station

12. Science potential with IceCube is vast:  Neutrino point source search (     Diffuse searches ( e,  and    more sensitive if there are more sources IceCube physics topics  Atmospheric neutrinos  Cosmic Ray (C.R.) composition  Supernova (SN)  Gamma Ray Bursts  Search for exotic particles and new physics. http://www.sciencemag.org/content/vol315/issue5808 Vol 315 (2007)

13. The IceCube Detector Counting House 1450 m 2450 m AMANDA IceTop Surface air shower array InIce 70+ strings, each with 60 digital optical modules (DOM) 17 m between modules 125 m string separation Instrumenting 1km 3 of Antarctic Ice to detect extraterrestrial neutrinos IceCube will detect neutrinos of all flavors at energies from 10 11 eV to 10 20 eV

14. Digital Optical Module (DOM) DOM - a complete data acquisition system: - internal digitization and time stamping the photonic signals from the PMT - can perform PMT gain and time calibration - transmitting digital data to the surface PMT Main Board Main Board (most of electronics) - PMT output collected with fast waveform digitizer chips that sample the signal 128 times at 200-700 MSPS - PMT signal is fed into 3 parallel 10-bit ADC with a nominal gain ratios 0.25:2:16. Combined they provide wide dynamic range from single p.e. to thousands p.e.

15. Time Resolution from LED flashers Method: flash an LED on a DOM and measure the arrival time of light reaching a nearby DOM RMS variation of time delay measured with flashers for 59 DOM pairs on one string. For most of the DOMs resolution better than 2 ns DOM 51 DOM 52 DOM 53 DOM 54 Photon arrival time delay at DOM 52 when DOM 53 is flashing.

16. Muon neutrino Electron neutrino Phototubes (km long) Track: + increased detection volume +  points along  , i.e. to source - cosmic ray  background - ok energy measured Cascade: e-m or hadronic showers -must be in detector -  background (brems’ng) - limited pointing capability + good energy measurement Neutrinos: How do we see them?

17. Energy Res. : log(E)~0.3 Angular Res.: 0.8 -2 deg Neutrinos Signature (Simulations) E = 375 TeV Energy Res. log(E)~0.1-0.2 Poor Angular Resolution 300m  +N  +...   +hadrons Muon neutrino Electron neutrino Tau neutrino a) E µ =10 TeV ~ 90 hits b) E µ =6 PeV ~1000 hits E = 10 PeV Double-bang signature above ~ 1 PeV Very low background Pointing capability E ~ dE/dx, E> 1 TeV

18. Origin of the neutrinos observed in the detector M.Kowalski [astro-ph/0505506]  atmospheric neutrinos (mostly  ) dN/dE~E -3.7  neutrinos from charm decay In the atmosphere dN/dE~ E -2.8  astrophysical neutrinos dN/dE~E -2.0 (model) signal

19. Extraterrestrial Neutrinos: Signals and backgrounds Low energy: Distinguish: -  (CR vs  ) by their direction - (atmospheric vs extrater.) by energy Above 10 5 TeV - small  and  bg produced in CR interactions with the Earth atmosphere. Distinguish  flavor by their topology High energy: Neutrinos (all flavors) interact in(or close to) the detector via: Muon channel: Cascade channel:

20. AMANDA IceCube Skiway Amundsen-Scott South Pole Station Geographic South Pole IceCube at the South Pole Drill Site Counting House

21. Getting there is half the fun New C-17 Old C-141 (photo by RGS) Transportation upgrades to Antartica….

22. Schedule and Logistics The new South-Pole station  Can work from December to mid-February  Logistics are a huge concern  Power - expensive!  3 winterover scientists operate and maintain instrument during winter  Weather is always a factor

23. Field team deals very well with issues and harsh conditions

24. Hotwater drill system Drill tower Hose reel DOMs

25. Hole Drilling Design goal: 40 hours to drill a hole 36 h Successfully used for three holes. Expected to save about 2 holes per season. 2007: Independent firn drill Depth (m) Time  2500 m deep, 60 cm dia. holes  5 Megawatt hot water drill  Speeds to 2.2 m/minute

26. IceCube Deployments to Date AMANDA 21 30 29 40 50 39 38 49 59 46 47 48 58 57 66 67 74 65 73 78 56 72 2004-2005 1 string deployed First data astro-ph/0604450 2005-2006 8 string deployed 2006-2007 13 strings deployed 1+8+13 = 22 strings to date Goal >=14 strings/season Completion by 2011. More than 25 % of full detector installed.  1424 sensors deployed, and 1403 sensors (98.5%) are commissioned and being used  Comparison to AMANDA-II: 85 of 677 sensors (12.5%) are not usable for technical reasons

27. April 29 2007 ( commissioning) IceDust layer (low rate) 2007 13-strings Deployment  Physics Run - started May 2007  Updated DAQ, triggers, monitoring system 1450m 2450m 0 50m

28.  Measurements: in-situ light sources, atmospheric muons and Dust Loggers (records dust layers with cm resolution): Ice Properties: scattering and absorption Average optical ice parameters: Dust Logger signal depth (m) DOM Occupancy abs ~110m@400nm sca ~ 20m@400 nm Scattering length varies from 6 to 30m depending on depth and location of dust layers (deposited by e.g. volcanic events over past thousands of years) Understanding ice properties - key to modeling IceCube Probability a DOM is hit in evts that have >7 hits on a string

29. Dust Logger

30. Bubble Camera - 2007 deployment DOM 60 Weight Stack Sphere 1 Sphere 2 String 57

32. Particle (  ) Tracking  Charged particles emit Cherenkov radiation angle  = Cos -1 (1/n) = 41 0  The photons scatter (L ~ 25 m)  Some (<10 -6 ) photons are observed in photodetectors  We measure points 0-30 meters from the  track  Angular resolution < 1 0 for long tracks  Noise  bremsstrahlung pair-creation e+e-e+e-  photo-nuclear  tracks lose energy by emitting , e + e - pairs and hadronic interactions (via virtual  ) DOM

33. Atmospheric muon neutrinos in 2006 2006 data: 90 days with 9 strings Data selection done online at S. Pole and transferred by satellite North Neutrino-induced muon candidate Dust layer

34. IC-9strings (first) analysis: Atmospheric muon neutrinos in 2006 Reconstructed Zenith Angle  (deg) Contamination at the horizon likely due to mis-reconstructed events (single shower) as being below the horizon.  After cuts: 234 events measured (211 expected from atm.  MC)  Reconstructed direction Reconstructed Azimuth Angle  (deg) Horizon arXiv:0705.1781 [astro-ph]

35.  Event rate: 610 Hz  Raw data: 180 GB/day  Uptime to date: 92%  Events recorded by June 28, 2007 1.65 x 10^9  Continuous data taking … Sufficient data to observe (diffuse) non-atmospheric neutrinos? IC-22 run status May 23, 2007 - start of IceCube science run Downgoing muons (background) Azimuth distribution illustrates detector response.

36. String Commissioning pDAQ IC36+ Commissioning(95%) Calibration (Geometry, DOMs) P&F IC36+ Commissioning DecJanFebMarApril IC22 Science runIC36+ Science run IC 36+ verification Finish Latecomers IC22  IC36+ Schedule Current status: Ready to go….winterovers arrive on ice Oct 22!! Bulk of drillers arrive on Oct 31

37. Future Plans  Above ~ 10 16 eV, the expected rates in IceCube are small  A ~100 km 3 detector is needed to see GZK  Protons and  have limited range. Only  probe sensitive to ‘EHE universe’ > 50 megaparsecs away  Coherent radio and/or acoustic detection of EHE showers may allow for an affordable detector

38. Summary  IceCube construction is well underway - More than 25% complete. - Completed detector in 2011.  Physics analysis underway. IceCube IC-9 atmospheric muon neutrino results IC-22 analyses on-going Stay tuned!

39. ANITA Gondola & Payload Antenna array Overall height ~8m Solar panels Antarctic Impulsive Transient Antenna Experiment searching for GZK neutrinos with radio detection in Antarctic ice neutrino Cascade: ~10m length air Ice- radio transparent medium RF Cherenkov Utilizes Askaryan effect

40. STATUS: 35 day flight this season 2006/7 ~15 days of good data - Haven’t unblinded yet - Might see a GZK neutrino, if lucky Payload was crunched on landing Next flight in 2008/9

41. ARIANNA concept 100 x 100 station array, ~1/2 Teraton ~300m Ross Ice Shelf, Antarctica

42. Sensitivity and limits S. Barwick ANITA sensitivity, 45 days total: ~5 to 30 GZK neutrinos IceCube: high energy cascades ~1.5-3 GZK events in 3 years

43. Oscar Blanch-Bigas Neutrino fluxes - upper limits

44. Supernova Monitor Amanda-II IceCube 0 5 10 sec Count rates LMC AMANDA II: 95% of Galaxy IceCube: Milky Way + LMC msec time resolution You are here

45. Data Acquisition and Trigger “Full” DAQ software & trigger Select time regions of interest using multiplicity, topology Events == time window Collect data for these windows Data filtering (muon, cascade) Reconstruct events Select interesting events for satellite transmission Monitoring, calibration, logging, control functions,… Master Clock Distribution InIce