IceCube project Shigeru Yoshida Dept. of Physics, Chiba University.

Bartol Research Inst, Univ of Delaware, USA Pennsylvania State University, USA University of Wisconsin-Madison, USA University of Wisconsin-River Falls, USA LBNL, Berkeley, USA UC Berkeley, USA UC Irvine, USA Bartol Research Inst, Univ of Delaware, USA Pennsylvania State University, USA University of Wisconsin-Madison, USA University of Wisconsin-River Falls, USA LBNL, Berkeley, USA UC Berkeley, USA UC Irvine, USA Univ. of Alabama, USA Clark-Atlanta University, USA Univ. of Maryland, USA IAS, Princeton, USA University of Kansas, USA Southern Univ. and A&M College, Baton Rouge Univ. of Alabama, USA Clark-Atlanta University, USA Univ. of Maryland, USA IAS, Princeton, USA University of Kansas, USA Southern Univ. and A&M College, Baton Rouge Universidad Simon Bolivar, Caracas,Venezuela Université Libre de Bruxelles, Belgium Vrije Universiteit Brussel, Belgium Université de Mons-Hainaut, Belgium Universität Mainz, Germany DESY-Zeuthen, Germany Universität Wuppertal, Germany Université Libre de Bruxelles, Belgium Vrije Universiteit Brussel, Belgium Université de Mons-Hainaut, Belgium Universität Mainz, Germany DESY-Zeuthen, Germany Universität Wuppertal, Germany Uppsala Universitet, Sweden Stockholm universitet, Sweden Kalmar Universitet, Sweden Imperial College, London, UK University of Oxford, UK Utrecht University, Utrecht, NL Uppsala Universitet, Sweden Stockholm universitet, Sweden Kalmar Universitet, Sweden Imperial College, London, UK University of Oxford, UK Utrecht University, Utrecht, NL Chiba University, Japan University of Canterbury, Christchurch, New Zealand University of Canterbury, Christchurch, New Zealand Who are we ?

AMANDA IceCube IceTop IceCube 80 strings 60 OMs/string 17 m vertical spacing 125 m between strings IceTop 160 tanks frozen-water tanks 2 OMs / tank First year deployment (Jan 2005) 4 IceCube strings (240 OMs) 8 IceTop Tanks (16 OMs) 10” Hamamatsu R m IceTop Tank deployed in 2004

Theoretical bounds and future atmospheric  W&B MPR DUMAND test string FREJUS NT-200 MACRO  NT-200+ AMANDA-II IceCube AMANDA-97 AMANDA-00 opaque for neutrons Mannheim, Protheroe and Rachen (2000) – Waxman, Bahcall (1999)  derived from known limits on extragalactic protons +  -ray flux neutrons can escape

Construction: 11/ /2009 AMANDA SPASE-2 South Pole Dome Skiway 100 m Grid North

Right now at the pole

DOM … a Key element in IceCube

Digital Optical Module (DOM) HV Base Main Board (DOM-MB) “Flasher Board” 10” PMT 13” Glass (hemi)sphere

PMT Absolute Calibration Qe x Ce N nm Use Rayleigh scattering for beam dumping (~1E-11) for SPE measurement

Setup ATTENUATOR Pressure meter Temp monitor

Chamber Center 窓１窓２ レーザー Baffle (beam size 1cm) Rotation bed Configuration Survey

Setup photo

– Light source (Laser Science VSL-337ND-S) N 2 laser lambda ＝ 337.1nm E max =300uJ (for 1p.e., E~2nJ) Pulse width<4nsec – Si energy probe (Laser Probe Inc. RjP-465) 500fJ-250nJ Detection area:1.0cm 2 Accuracy=+-5% MODULE Pressure and Temperture monitored by Pressure meter and Platinum resistor

Data Analysis QE(absolute efficiency) = photoelectron # / incidental photon # I. Estimate photoelectron # per laser shot photoelectron # = -ln(N ped /N all ) II. Estimate scattered light yield Y = incidental photon # / initial laser photon ~ aperture x Cross Section

Laser Energy Profile

Signal subtraction

Calculation of “light yield” Typically E-11 dumped

2 Dimensional Absolute Efficiency SF0077

Center Edge ADC ADC spectrum of Center and Edge of photocathode

SF0077, SF0050, SF Dimensional Absolute Efficiency

SF0077 Really see only scattered photons? -> 'YES' There's no other factors(offset) for data

Typical Error Budget ➢ Statistics ● photoelectron # : 10% ➢ Systematics photoelectron # : 1% Light yeild (aperture) : 4% Initial photon fluctuation : 4% Pressure : 1% Photon energy probe: 5% Total Error Budget : 12.7%

FY2005 Goal PMTDOM Standard Candle (absolutely calibrated, 2D scanned)

FY2005 Goal 1400 m 2400 m AMANDA South Pole IceTop Skiway “Perfect” standard Candle