IceCube Neutrino Telescope Astroparticle Physics at the South Pole Brendan Fox Pennsylvania State University for the IceCube Collaboration VLVNT08 - Very Large Volume Neutrino Telescopes
2008 - Toulon, France

The IceCube Collaboration 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 29 institutions ~250 people University of Wisconsin-Madison, USA University of Wisconsin-River Falls, USA LBNL, Berkeley, USA Southern University and A&M College, Baton Rouge, USA USA (11) Japan Europe (15) Chiba University, Japan University of Canterbury, Christchurch, NZ New Zealand 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 ANTARCTICA Universität Wuppertal, Germany MPI Heidelberg, Germany RWTH Aachen Uppsala University, Sweden Stockholm University, Sweden Oxford University, UK Utrecht University, Netherlands Amundsen-Scott Station

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

Digital Optical Module (DOM) 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 ms combined waveform length Variable sampling speed: 250 - 800 MHz Up to 200-300 p.e./10 ns charge resolution

IceCube Digital Optical Module

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

DOMCal Summary for FAT22 Budweiser-TP4Y0031 1260 Volts 1340 Volts Gain vs. HV Fit 1e7 DOMCal Summary for FAT22 Budweiser-TP4Y0031 1.6pC Charge (pC) HV Most PMTs achieve 1e7 at 1100-1600 Volts • Require 5e7 at <2kV

Time Resolution Test Laser pulses @15kHz 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 ~5mV @1e7 digitizer 0.1mV/count Time computed from leading edge (50% of pulse maximum) Resolution 2-3nsec includes DAQ time slewing relative to Sync DOM

Dark rate monitoring ~120 hours checking for: Average Rate 2-3kHz Temp (°C) –35°C –10°C 5e7 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

Construction Plan Overview 08-09 09-10 IC-40 DEPLOYED AMANDA … drilling/deployment plans for the 10-11 season being discussed

Schematic of Hot Water Drilling

String Deployment

2007-08 Season … 18 strings deployed!

String 39 two-week freeze-in movie Commissioning String 39 two-week freeze-in movie

Commissioning 76 528 820 1136

DOM Survivability 76 DOMs 589 DOMs 1390 DOMs 2515 DOMs 66-33 “New_York” and 66-34 “Dou_Mu” go high current 39-61 “Hydrogen” PMT breaks 54-47 “Garbanzo_bean” stops communicating 39-22 “Liljeholmen” stops communicating properly 39-21 “Aspudden” slows down 30-60 “Rowan” stops communicating

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

Initial Timing Verification
dom 10 17m dom 11 string 76

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

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

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

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) RESULT Online filtering at Pole to isolate sample of “good” up-going candidates Transfer this sample by satellite to North 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 137.4 live-days of data (purity of neutrino sample > 95%) Mis-reconstructed atmospheric muons RESULT J. Pretz, Ph.D. thesis (Maryland) [DRUM 1903-4163]

Neutrinos in IC-9 (2006) ZENITH AZIMUTH t ~ 90-110° … muon background peaks in  artifact of the IC-9 string configuration

Prospects for IC-22 … IC-40 … (Integrated Exposure) “Actual” Graph shows cumulative km3·yr of exposure × volume 1 km3·yr reached 2 years before detector is completed Close to 4 km3·yr at the beginning of 1st year of full array operation. NOTE: not adjusted for actual

Upcoming Season Plans 1996-2001: AMANDA 2004-05: 1 string 2005-06: 8 2006-07: 13 12 planned 2007-08: 18 14 planned 2008-09: 16+ 2009-10: 16+ 2010-11: 7+ 09-10 08-09

String Layout Options DEEP CORE UHE STRINGS Preliminary design Olaf Schulz Preliminary design 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 days @ 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 08-09 - UHE arrangement of final strings underway … Elisa Resconi discussed the physics expected from IceCube + these extensions.

BACKUP SLIDES

} LC IceCube Triggering InIce: 4 3 5 2 1 InIce: - Local coincidence between neighboring modules (variable time window: presently = 1 us) On the surface: - require NDOMs  8 within 5 us window Form event from all “hits” within ±8 us of trigger } LC

Ice Properties Bubbles at higher depth dust layers Scattering Absorption Bubbles at higher depth dust layers Average optical parameters: abs ~ 110 m @ 400 nm sca ~ 20 m @ 400 nm