IceCube Neutrino Telescope Astroparticle Physics at the South Pole Brendan Fox Pennsylvania State University for the IceCube Collaboration VLVNT08 - Very Large Volume Neutrino Telescopes Toulon, France

USA (11) Europe (15) Japan New Zealand Bartol Research Institute, Delaware, USA Pennsylvania State University, USA UC Berkeley, USA UC Irvine, USA Clark-Atlanta University, USA University of Alaska, Anchorage, USA Univ. of Maryland, USA University of Wisconsin-Madison, USA University of Wisconsin-River Falls, USA LBNL, Berkeley, 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 Universität Wuppertal, Germany MPI Heidelberg, Germany RWTH Aachen Uppsala University, Sweden Stockholm University, Sweden Oxford University, UK Utrecht University, Netherlands Chiba University, Japan University of Canterbury, Christchurch, NZ ANTARCTICA The IceCube Collaboration Amundsen-Scott Station 29 institutions ~250 people

Detecting Neutrinos In Ice Muon neutrino Electron neutrinoTau neutrino Phototubes  Track: + increased detection volume - energy measurement “okay” +  points along , i.e. to source Cascade: - must be in detector + good energy measurement - limited pointing capability -  background (brems’ng) - cosmic ray  background Hybrid: - must be in detector + best energy measurement + pointing capability + nil background - need E>o(1000 TeV) (also includes NC ,  )

IceCube-AMANDA AMANDA Eiffel Tower Svenska Dagbladet Digital Optical Module (DOM) currently instrumented IceTop - ICECUBE : 4800 DOMs on 80 strings - ICETOP : 160 Ice-Cherenkov tank surface array (IceTop) - AMANDA: 677 OMs surrounded by IceCube

IceCube Digital Optical Module Low intrinsic noise ~ 500 Hz Fast digitization 30 ms/channel Waveform: 4 channels/128 sample Low power consumption 5 W per DOM Up to 12  s combined waveform length Variable sampling speed: MHz Up to p.e./10 ns charge resolution

IceCube Digital Optical Module

DOM Final Acceptance Testing ~60 DOMs at time 3 identical setups at UW-Madison (USA) 1 setup at DESY-Zeuthen (Germany) 1 setup at Uppsala University (Sweden) freezer

Most PMTs achieve 1e7 at Volts 1260 Volts1340 VoltsGain vs. HV Fit 1e7 DOMCal Summary for FAT22 Budweiser-TP4Y pC Charge (pC) HV Require 5e7 at <2kV

Laser occupancy ~0.04 laser trigger times recorded in dedicated “Sync DOM” PMT signal recorded in DOM 100,000 synchronized hits sampling time 3.5nsec pulse height digitizer 0.1mV/count Time computed from leading edge (50% of pulse maximum) Resolution 2-3nsec includes DAQ time slewing relative to Sync DOM Time Resolution Test

Dark rate monitoring ~120 hours checking for: Average Rate 2-3kHz –includes non-PMT contributions –will be 650Hz in ice (or 300Hz without double- counting time-correlated noise) No instabilities Rate (kHz) Temp (°C) –35°C –10°C 5e7

Construction Plan Overview IC-40 DEPLOYED AMANDA … drilling/deployment plans for the season being discussed

Schematic of Hot Water Drilling

String Deployment

Season … 18 strings deployed!

Commissioning String 39 two-week freeze-in movie

Commissioning

76 DOMs589 DOMs1390 DOMs “Liljeholmen” stops communicating properly “Rowan” stops communicating 2515 DOMs “Hydrogen” PMT breaks “New_York” and “Dou_Mu” go high current “Garbanzo_bean” stops communicating “Aspudden” slows down DOM Survivability

DOM-to-DOM Synchronization RAPCAL: Sync each DOM to GPS time

Initial Timing Verification 17m dom 10 dom 11 string 76

Initial Timing Verification Means Sigmas … timing of all DOMs within spec (  <3 ns)

Timing Verification With Muons string 49 Cherenkov Photons  track Emission on the Cherenkov Cone

Long-Term Stability of Timing track position of leading edge on monthly basis … … timing stable over IC-22 data-taking period

Initial String Geometry

String Geometry - z check

For string 64, the stage 1 depth was a bit of guess since the pressure sensor broken.

String Geometry - (x,y) check Select well reconstructed muon tracks Vary (x,y) of DOM … look at the log-likelihood -vs- (x,y) Minimium will be where the DOM is situated MC studies still underway … technique looks promising

Readout Scheme

Detector Monitoring Snapshot

Neutrinos in IC-9 (2006) J. Pretz, Ph.D. thesis (Maryland) [DRUM ] 1.Online filtering at Pole to isolate sample of “good” up-going candidates 2.Transfer this sample by satellite to North 3.More refined analysis … … Log-likelihood reconstruction, etc. … apply additional quality cuts, etc. to gain more down-going muon rejection Ratio of data to simulation: At selected cut strength of 10: 234 up-going  in live-days of data (purity of neutrino sample > 95%) RESULT Mis-reconstructed atmospheric muons

Neutrinos in IC-9 (2006) t ~ ° … muon background peaks in  artifact of the IC-9 string configuration ZENITHAZIMUTH

Prospects for IC-22 … IC-40 … (Integrated Exposure) Graph shows cumulative km 3 ·yr of exposure × volume 1 km 3 ·yr reached 2 years before detector is completed Close to 4 km 3 ·yr at the beginning of 1 st year of full array operation. “Actual” NOTE: not adjusted for actual

Upcoming Season Plans : AMANDA : 1 string : : 13 –12 planned : 18 –14 planned : : :

String Layout Options Olaf Schulz Preliminary design DEEP CORE UHE STRINGS

Conclusions Drilling/deployment of IceCube strings is going well Deployment of IceTop stations also on target (40 stations deployed) IceCube components (DOMs/daq/triggers/filter/etc.) up and going IceCube is working as expected … first physics results from IC-22 (318 95% uptime) … IC-40 data-taking started April 1, 2008 IceTop-40 is working too … tank/station performance as per specs … first physics physics from IC-22 being prepared now AMANDA integrated into IceCube … low energy results improved by using IceCube as veto In the future, - Low energy core planned … first string to be deployed UHE arrangement of final strings underway … Elisa Resconi discussed the physics expected from IceCube + these extensions.

BACKUP SLIDES

IceCube Triggering InIce: - Local coincidence between neighboring modules (variable time window: presently = 1 us) On the surface: - require N DOMs  8 within 5 us window Form event from all “hits” within ±8 us of trigger } LC

Scattering Absorption Bubbles at higher depth dust layers Average optical parameters: abs ~ nm sca ~ nm Ice Properties