IceCube project

Shigeru YoshidaDept. of Physics, Chiba University.

Bartol Research Inst, Univ of Delaware, USAPennsylvania State University, USAUniversity of Wisconsin-Madison, USAUniversity of Wisconsin-River Falls, USALBNL, Berkeley, USAUC Berkeley, USAUC Irvine, USA

Bartol Research Inst, Univ of Delaware, USAPennsylvania State University, USAUniversity of Wisconsin-Madison, USAUniversity of Wisconsin-River Falls, USALBNL, Berkeley, USAUC Berkeley, USAUC Irvine, USA

Univ. of Alabama, USAClark-Atlanta University, USAUniv. of Maryland, USAIAS, Princeton, USAUniversity of Kansas, USASouthern Univ. and A&M College, Baton Rouge

Univ. of Alabama, USAClark-Atlanta University, USAUniv. of Maryland, USAIAS, Princeton, USAUniversity of Kansas, USASouthern Univ. and A&M College, Baton Rouge

Universidad Simon Bolivar, Caracas,Venezuela

Université Libre de Bruxelles, BelgiumVrije Universiteit Brussel, BelgiumUniversité de Mons-Hainaut, BelgiumUniversität Mainz, GermanyDESY-Zeuthen, GermanyUniversität Wuppertal, Germany

Université Libre de Bruxelles, BelgiumVrije Universiteit Brussel, BelgiumUniversité de Mons-Hainaut, BelgiumUniversität Mainz, GermanyDESY-Zeuthen, GermanyUniversität Wuppertal, Germany

Uppsala Universitet, SwedenStockholm universitet, SwedenKalmar Universitet, SwedenImperial College, London, UKUniversity of Oxford, UKUtrecht University, Utrecht, NL

Uppsala Universitet, SwedenStockholm universitet, SwedenKalmar Universitet, SwedenImperial College, London, UKUniversity of Oxford, UKUtrecht University, Utrecht, NL

Chiba University, JapanChiba University, Japan

University of Canterbury, Christchurch, New Zealand

University of Canterbury, Christchurch, New Zealand

Who are we ?

AMANDA

IceCube

IceTop

IceCube80 strings

60 OMs/string17 m vertical spacing

125 m between strings

IceTop160 tanks

frozen-water tanks2 OMs / tank

First year deployment (Jan 2005) 4 IceCube strings (240 OMs)

8 IceTop Tanks (16 OMs)

10” Hamamatsu R-7081

1200 m

IceTop Tank deployed in 2004

Theoretical bounds and future

atmospheric

W&B W&B

MPRMPR

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: 11/2004-01/2009

FY04:6

FY05:12FY06:16

FY07:16

FY08:16 FY09:14

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 CalibrationQe x CeN2 laser @ 337.1 nmUse Rayleigh scattering for beam dumping (~1E-11) for SPE measurement

Setup

ATTENUATOR

PressuremeterTemp

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)

N2 laser lambda ＝ 337.1nmEmax=300uJ (for 1p.e., E~2nJ)

Pulse width<4nsec– Si energy probe

(Laser Probe Inc. RjP-465)

500fJ-250nJDetection area:1.0cm2

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 shotphotoelectron # = -ln(Nped/Nall)

II. Estimate scattered light yieldY = incidental photon # / initial laser photon

~ aperture x Cross Section

Laser Energy Profile

Signal subtractionsf0077@1atm

Calculation of “light yield”

Typically 4.764957518892241E-11 dumped

2 Dimensional Absolute Efficiency

SF0077

Center Edge

ADC ADC

ADC spectrum of Center and Edge of photocathode

SF0077, SF0050, SF0061

2 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 GoalPMT DOM

Standard Candle (absolutely calibrated, 2D scanned)

FY2005 Goal

1400 m

2400 m

AMANDA

South Pole

IceTop

Skiway

“Perfect” standard Candle