IceCubea kilometer-scale deep-ice observatory

in Antarctica

Olga BotnerUppsala university, Sweden

Neutrino 2004, June 14-19, 2004

http

:// i

cecu

be.w

isc.

edu

http

:// i

cecu

be.w

isc.

edu

copyright ©West Nottinghamshire College 2003

The location – at the bottom of the world

Distance

from Paris

15440 km

and landing

Aerial View of the Amundsen-Scott Research Station

going there …

Photo http://www.ifa.hawaii.edu/~hsieh/

IceCube – a ”next generation” observatory

kilometer-scale successor to AMANDA

detection of Cherenkov light from the charged particles produced when a interacts with rock or ice

direction reconstructed from the time sequence of signals

energy measurement – counting the number deposited p.e. waveform read out

Expected performance wrt AMANDA increased effective area/volume superior angular resolution superior energy resolution

astronomy requires km-scale detectors astronomy requires km-scale detectors

ultrahigh energy ’s associated with the sources of

high energy cosmic rays top-down scenarios: decays of massive cosmological relics bottom-up scenarios: ”cosmic accelerators” accreting black holes (eg AGN) colliding neutron stars/black holes

fireball (eg GRB)

cosmogenic ’s supernova ’s dark matter WIMP, Kaluza-Klein exotica monopoles, Q-balls, mini black holes

p + (p or ) e ,

The Science

IceCube conceptDeep ice array 80 strings / 60 OM’s each 17 m OM spacing 125 m between strings hexagonal pattern over 1 km2

geometry optimized for detection of TeV – PeV (EeV) ‘s based on measured absorption

& scattering properties ofAntarctic ice for UV – blue

Cherenkov light

Surface array IceTop 2 frozen-water tanks (2 OM’s each) on top of every string

IceTop + IceCube: 1/3 km2 srfor coincident tracks

VETO against

All downward events E > 300 TeV with trajectories inside IceTop

Larger events falling outside

CALIBRATION

of angular response with tagged

Expect ~100 tagged air showers/day

with multi-TeV ’s in IceCube

Muon survey of IceCube

FY04:6

FY05:12FY06:16

FY07:16

FY08:16 FY09:14

Large showers with E ~ 100-1000 PeVwill clarify transition from galactic toextra-galactic cosmic rays

IceCube layout

Measure

energy spectrum

chemical composition

Measure

energy spectrum

chemical composition

Cosmic Ray physics

Showers triggering 4 stations give ~300 TeV threshold for EAS array

Showers triggering 4 stations give ~300 TeV threshold for EAS array

IceCube - Icetop coincidences

Investigate transition to

extragalactic CR

Investigate transition to

extragalactic CR

Small showers (2-10 TeV)associated with the dominant background detected as 2-tank coincidences at a station.

Small showers (2-10 TeV)associated with the dominant background detected as 2-tank coincidences at a station.

Energy range 1015 eV - 1018 eV

Digital Optical module (DOM)

a self-contained ”mini”-

DAQ

records timestamps digitizes stores transmits to surface at request

an optical sensor10 inch Hamamatsu R-7081

mu metal cage

PMT

penetrator HV board

flasher board

DOMmain board

pressure sphere

optical gel

delay board

Dark noise rate < 1 kHz SN monitoring within

our Galaxy

DOM Mainboard

fast ADC recording at 40 MHz over 5 s

event duration in ice

2xATWD

FPGA

Memories

HV Board Interface

CPLD FPGA (Excalibur/Altera) reads out the ATWD

handles communications time stamps

waveformssystem time stamp resolution 7 ns wrt

master clock

FPGA (Excalibur/Altera) reads out the ATWD

handles communications time stamps

waveformssystem time stamp resolution 7 ns wrt

master clock

oscillator (Corning Frequency Ctl) running at 20 MHz

maintains f/f < 2x10-10

2 four-channel ATWDsAnalog Transient Waveform

Digitizerslow-power ASICs

recording at 300 MHz over first 0.5s

signal complexity at the start of event

2 four-channel ATWDsAnalog Transient Waveform

Digitizerslow-power ASICs

recording at 300 MHz over first 0.5s

signal complexity at the start of event

Dead time < 1%

Dynamic range - 200 p.e./15 ns- 2000 p.e./5 s

energy measurement (TeV – PeV)

-time stamped w.f. recorded & analyzed

- downgoing muons detected

- photon timing accuracy in ice < 8 ns

- local clock calibration < 5 ns r.m.s.

- 15% of waveforms have > 1 p.e.

IceCube design works

IceCube physics performance simulations benefit from AMANDA experience

IceCube will be able to identify tracks from for E > 1011 eV cascades from e for E > 1013 eV for E > 1015 eV

Background mainly downgoing cosmic ray ’s(+ time coinc. ’s from uncorrelated air showers) exp. rate at trigger level ~1.7 kHzatm. rate at trigger level ~300/day

Rejected using direction/energy/flavor id temporal/spatial coincidence w. source

for E < 1PeV focus on the Northern sky

for E > 1PeV sensitive aperture increases w. energy full sky observations possible

Eµ=10 TeV

IceCube effective area and angular resolutionfor muons

Galactic center

E-2 spectrum

quality cuts and bkgr suppression (atm reduction by ~106)

further improvement expected

using waveform info

further improvement expected

using waveform info

Median angular reconstruction

uncertainty ~ 0.8

Diffuse flux / Point sourcesObjective (after removal of atm background): reject the steep energy spectrum of atm retain as much signal as possible from a (generic) E-2 spectrum

Use optimized energy cut E number of hit OM’s

Eµ=6 PeV, 1000 hitsEµ=10 TeV, 90 hits

Diffuse hard E cutE > 100 TeV

Point sources softer E cut

+ spatial correlation

Assume generic flux dN/dE = 10 –7 E-2 (cm-2s-1sr-1GeV)

Expect

~103 events/year after atm rejection

~75 events/year after energy cut

cf background 8 atm

atm v

signal

Sensitivity (1 y): 8.110-9 E-2

(cm-2s-1sr-1GeV)

blue: after atm rejectionred: after Ecut

Diffuse flux

Steady point sourcesSearch cone 1 opening half-angle+ ”soft” energy cut (< 1 TeV)

Transient point sources – eg GRB

Essentially background-free search energy, spatial and temporalcorrelation with independent observation

For ~1000 GRB’s observed/yearexpect (looking in Northern sky only) signal: 12 background (atm ): 0.1

Sensitivity GRB (1 y): ~0.2 WB

Excellent prospects for detection of GRB ’s within 1-2 years-> if models realistic

Sensitivity point sources (1 y):

5.510-9 E-2 (cm-2s-1GeV)

Cascadese e

Lcascade ~10 m small cf sensor spacing”spherical” energy deposition

at 1 PeV, Øcascade ~ 500 m

~10% in log(E/TeV)

E = 375 TeV

IceTop veto on cosmics

IceTop veto on cosmics

C.O.G. insidearray

C.O.G. insidearray

“double bang”

~300m for PeV

E << 1 PeV 2 cascades coincideE 1 PeV ”double bang”E >> 1 PeV ”lollipop” (partialcontainment, reconstruct track

+ 1 cascade)

sensitivity to all flavors4 coverage

For diff

use fl

ux expect sim

ilar s

ensitivity

in the ca

scade ch

annel as i

n the m

uon channel

Considera

ble impro

vement of o

verall s

ensitivity

Neutralino dark matterastro-ph/0401113 (Lundberg/Edsjö)WIMP orbits in the solar system

perturbedRates from the Earth affected Rates from the Sun less affected

Direct and indirect searches complementary Past/present history of solar syst. Low/high energy tail of vel. distr.

Disfa

vored

by direct search

Sun

Earth

AMANDA system IceCube

AMANDA IceCubePower consum. 2 MW 5MWTime to 2400 m 120-140 h 35-40 hFuel (gal/hole) 10000-12000 7000-8000 Set-up time 5 – 6 weeks 18-25 d

AMANDA IceCubePower consum. 2 MW 5MWTime to 2400 m 120-140 h 35-40 hFuel (gal/hole) 10000-12000 7000-8000 Set-up time 5 – 6 weeks 18-25 d

Goals

18 holes/season

2450 m deep

straight within 1m

quality logged

Goals

18 holes/season

2450 m deep

straight within 1m

quality logged

Enhanced Hot Water Drill

Hose-reel atSouth Pole (Jan 2004)

Hose-reel with hose,built at Physical Sciences Laboratory

UW-Madison (Nov 2003)

In-D oor deploym ent

DOM Hub

Cable Winch

Slip Ring

Deployment Room

Tower Operations Structure(TOS)

OMs

DAQ

Entire string can be operated as soon as the OMs are connected.

Can operate string during drop

Mounting, testing + drop of string with 60 OMs

expected to take ~ 20 hours

Mounting, testing + drop of string with 60 OMs

expected to take ~ 20 hours

Status of IceCube project many reviews – international and within the U.S. - strongly emphasize

the exciting science which can be performed with IceCube

in Jan 2004, the U.S. Congress approvedthe NSF budget including the full IceCube MRE

significant funding approved also in Belgium, Germany and Sweden

in Feb 2004, NSF conducted a baseline review “go ahead”

deployment over 6 yearsIceCube strings IceTop tanks4 8 Jan 200516 32 Jan 200632 64 Jan 200750 100 Jan 200868 136 Jan 200980 160 Jan 2010

AMANDA / IceCube integrationAmanda now runs with TWR data similar in structure to IceCube work on a s/w trigger

Position of 1st IceCube strings as close to Amanda as possible for verification & cross-calibration … but logistics and

safety requirements

1. 1st IceCube strings: Amanda as calibration device 2. IceCube ~ 20 strings + Amanda: powerful combined detector3. Full IceCube: Amanda included as a fully integrated,

low threshold subdetector

CONTINUOUS SCIENCE OUTPUT DURING CONSTRUCTIONCONTINUOUS SCIENCE OUTPUT DURING CONSTRUCTION

drill development on schedule for operation at Pole in Jan 2005

instrumentation production for the 4 string first season starts this summer

50% PMTs delivered – on schedule 3 DOM production sites

Wisconsin 290 1st season DESY 60 1st season Sweden 50 1st season

spheres ordered – 40K depleted Benthos (dark noise ~0.8 kHz) DOM mainboard – designed @ LBNL tests OK DAQ S/W developed data transfer DOM DOM Hub Data Collection prog tested implementation for first season’s DAQ cables – Ericsson, Sweden / JDR, Netherlands preparing for analysis of early data (calibration, testing)

4 DOM’s are collecting IceTop data using test s/w

Status of IceCube construction

View of DOMs

IceTop tank with hood at the South Pole – Nov 2003

IceTop Stations with DOMs – January 2004

Digitized muon signals from DOMs

Am

plit

ude

(AT

WD

cou

nts)

vs

tim

e (n

s)

power cable

signal, freeze control,

temperature controlcables

1st challenge – successful deployment

of strings 2004/2005

Summary

IceCube is for real ! - and moving ahead at full speedAMANDA experience provides for huge benefits

- both logistics-wise and for simulations/reconstruction

IceCube is expected to be considerably more sensitive than AMANDA provide new opportunities for discovery with IceTop – a unique tool for cosmic ray physics

first data for Neutrino 2006

data taking during construction first data augment AMANDA data later AMANDA an integral part of IceCube

USA (12)USA (12)

Europe (11)Europe (11)

VenezuelaVenezuela

JapanJapan

New ZealandNew Zealand

• Bartol Research Institute, Delaware, USA• Univ. of Alabama, USA• Pennsylvania State University, USA• UC Berkeley, USA• Clark-Atlanta University, USA• Univ. of Maryland, USA

• Bartol Research Institute, Delaware, USA• Univ. of Alabama, USA• Pennsylvania State University, USA• UC Berkeley, USA• Clark-Atlanta University, USA• Univ. of Maryland, USA

• IAS, Princeton, USA• University of Wisconsin-Madison, USA• University of Wisconsin-River Falls, USA• LBNL, Berkeley, USA• University of Kansas, USA• Southern University and A&M College, Baton Rouge, USA

• IAS, Princeton, USA• University of Wisconsin-Madison, USA• University of Wisconsin-River Falls, USA• LBNL, Berkeley, USA• University of Kansas, USA• Southern University and A&M College, Baton Rouge, USA

• Universite Libre de Bruxelles, Belgium• Vrije Universiteit Brussel, Belgium• Université de Mons-Hainaut, Belgium• Universität Mainz, Germany• DESY-Zeuthen, Germany

• Universite Libre de Bruxelles, Belgium• Vrije Universiteit Brussel, Belgium• Université de Mons-Hainaut, Belgium• Universität Mainz, Germany• DESY-Zeuthen, Germany

• Universität Wuppertal, Germany• Uppsala university, Sweden• Stockholm university, Sweden• Imperial College, London, UK• University of Oxford, UK• NIKHEF, Utrecht, Netherlands

• Universität Wuppertal, Germany• Uppsala university, Sweden• Stockholm university, Sweden• Imperial College, London, UK• University of Oxford, UK• NIKHEF, Utrecht, Netherlands

• Chiba university, Japan• University of Canterbury, Christchurch, NZ

• Chiba university, Japan• University of Canterbury, Christchurch, NZ

ANTARCTICA

• Universidad Simon Bolivar, Caracas, Venezuela

THE END