Status of ANTARES: An Undersea Neutrino Telescope Paschal COYLE, - - PowerPoint PPT Presentation

Status of ANTARES: An Undersea Neutrino Telescope

Paschal COYLE, Centre de Physique des Particules de Marseille

School and Workshop on Neutrino Particle Astrophysics Les Houches, 21-31 Jan 2002

Low Energy (10 GeV < Eν < 100 GeV) Medium Energy (10 GeV < Eν < 1 TeV) High Energy (Eν > 1 TeV) ν oscillations (observation of first

• scillation minimum

from atmospheric ν) neutralino search (signal from annihilating WIMPs in the Earth, the Sun and the Galaxy) ν from galactic and extra- galactic sources (x-ray binaries, SNR, AGN, GRB)

Scientific Motivation Scientific Motivation

+Oceanography

• measurements of oceanographic parameters of deep sea
• studies of bioluminescence

ANTARES Timeline ANTARES Timeline

Collaboration formed Collaboration formed EO Cable deployed and tested EO Cable deployed and tested Sector Line mechanical test Sector Line mechanical test Sector Line deployment Sector Line deployment Deployment of lines 1 to 10 Deployment of lines 1 to 10 0.1km 0.1km2

2 detector

detector complete complete Site evaluation programme Site evaluation programme to select a suitable site to select a suitable site “Demonstrator” “Demonstrator” line deployment line deployment and operation and operation Technical design report completed Technical design report completed

ANTARES Collaboration

• Univ. de H.-A., Mulhouse

λabs ~ 55-65 m ; λscat > 100 m at large angles

Water Transparency Water Transparency

Biofouling Biofouling Optical Backgrounds Optical Backgrounds

For θ > 90º transmission loss < 1.5% in 1 yr (and saturates)

Short bursts (bioluminescence) over a continuous background (40K). ~ 60 kHz (10” PM)

• f sea current

~5% of time a PMT is unusable

Demonstrator Line Demonstrator Line

Boat

Real time sonar display

Line (descending)

• Immersed: Nov. 99 - June 00
• Depth of 1100 m
• 350 m line height, 16 storeys
• 7 PMTs, prototype acoustic positioning system
• Line controlled and readout via

37 km electro-optical cable, analog transmission (digital for 0.1 km2)

Time (min)

5cm

Acoustic Positioning Acoustic Positioning Prototype Prototype

~ 1 cm

Inter-transponder

≤ 3 cm

Range-Transponder

~ 1 cm

Inter-distancemeter

Precision (σ)

distance

4 transponders 3 distancemeters

Y coord. Range 3 (m)

Triangulation → ~5 cm final precision

Reconstruction of atmospheric Reconstruction of atmospheric µ µ events events

50 000 events with 7-fold coincidences recorded Depth vs. time pattern used to generate hyperbolic fit 40K hits filtered out by reconstruction software

z(m) ct (m)

ANTARES Site ANTARES Site

Antares Site 60Km SE Marseille Depth 2400m Shore Base La Seyne-sur-Mer

• 2400m

40 km

Land Cable

Detector Assembly Hall Foselev Marine

Installations in La Seyne sur Mer Installations in La Seyne sur Mer

Power Hut

Les Sablettes

Shore Station

Villa Michel Pacha

Submarine cable (Fibre optics + power )

ANTARES 0.1km2 detector

60 m

• 10 lines
• 30 storeys / line
• 3 PMT / storey

350 m 100 m 12 m Junction box Readout cables 40 km to shore

2400m

A Detector Line A Detector Line

Buoy Electro-mechanical Cable

• mechanical support
• core with 21 optical fibres and power lines

Optical Module (3 per storey)

• 10” PMT, active base, LED calibration system

Sea bed Bottom String Structure

• acoustic string release system

Local Control Module: Electronics container

• front end ASIC, “ARS”: time, amplitude
• acoustic positioning
• data acquisition: 5 storeys → sector ethernet 1Gb/s

String Control/Power Module: Electronics containers

• string power supplies
• data acquisition: 6 sectors → DWDM → 6x1Gb/s on 1 fibre

Interlink cable,

• wet-mateable connector: 4 optical fibres+ 2 power lines

12m

100m 6 sectors* 5 storeys *3 PMs =90 PMs/line LED Beacon (one per sector)

Glass sphere (Nautillus) Photomultipler: 10 inch Hamamatsu Mu metal magnetic shield Active PMT base (ISEG)

The Optical Module The Optical Module

LED pulser

Optical gel

Expected Performance: Expected Performance: Effective Area Effective Area

trigger reconstruction selection Geometrical surface

Angular Resolution Energy Resolution

• 5 GeV < E < 100 GeV

Energy estimated from µ range σE ~ 3 GeV

• E > 1 TeV

σE / E ~ 3 Includes all effects (TTS, positioning, scattering etc.,) except phase→group velocity of light

Expected Performance: Resolution Expected Performance: Resolution

• 10 TeV

View of the Sky View of the Sky

AMANDA (South Pole) ANTARES (43° North)

(Gamma ray flux >100 MeV observed by EGRET)

Never seen

Indicative, assumes efficiency=100% for 2π downwards

• Sky coverage: 3.6π sr
• overlap with AMANDA
• Galactic Center surveyed

Need a Neutrino Télescope in both Northern and Southern Hemispheres

~Never seen

View of the Sky (microquasars)

AMANDA (South Pole) ANTARES (43° North)

(Gamma ray flux >100 MeV observed by EGRET) Source type number of sources seen by Antares EGRET AGN 94 86% EGRET Pulsars 5 100% Known Microquasars 19 74% Indicative, assumes efficiency=100% for 2π downwards

Check of Pointing Calibration Using Moon Shadow Check of Pointing Calibration Using Moon Shadow

Look for deficit of downgoing muons from moon direction

Minimium observation (2σ) time 2 years Misalignment >0.5° ⇒ moon shadow not visible anymore

Angular resolution degraded for downward going muons

P(µ→τ)= sin22θ sin2(1.27 ∆m2L/E), ∆m mass difference, θ mixing angle E energy of ν, L oscillation length

Atmospheric Neutrino Oscillations Atmospheric Neutrino Oscillations

Ideal Reconstruction

ν ν ν ν ν ν ν ν

Simulation, 0.1km2, 3 years

L~Dearth cos θµ

Comparison with other Experiments Comparison with other Experiments

90% CL

(2007)

• Bartol atmospheric ν flux
• Normalization left free
• 3 years data taking

(~2000 evts) Statistical errors+ 5% bin-by-bin uncorrelated systematic (prel.)

Preliminary

Search for Neutralino Annihilation Search for Neutralino Annihilation

ρχ ~ 0.3 GeV/ cm3, vχ~270 km/sec

Halo of Dark Matter:

χ

WIMP looses energy by elastic interaction if V< Vescape =>capture capture + annihilation balance => constant density in core

W→µνµ W→µνµ

χ χ χ+

b→cµνµ b→cµνµ

χ χ b

~

hard spectrum (ττ if Mχ<MW) soft spectrum (tt if Mχ>Mtop)

Expected Muon Flux Limits for Sun Expected Muon Flux Limits for Sun

• Apply standard selection
• Add 3° pointing cut around

calculated sun direction

• Predicted backgrounds from

atmospheric neutrinos: 1.7/year

• The band is the range covered by

the hard and soft spectra

• Assumes no oscillations
• Dedicated reconstruction will

significantly improve the sensitivity in the low mass region

Preliminary

Predicted Neutrino Flux from the Sun Predicted Neutrino Flux from the Sun

Excluded by LEP and b→ s gamma

excluded by Ωwimph2>1

• mSUGRA scan using SUSPECT
• fluxes from DARKSUSY

A0=0, µ>0, tanβ=10 log neutrino flux from sun (/km2/yr)

mixed gaugino pure gaugino

Comparison with mSUGRA Models and Direct Detection Comparison with mSUGRA Models and Direct Detection

mSUGRA Models considered: A0=0, µ>0, tanβ=10, M1/2=0-800 GeV, M0=0-1000 GeV +Ωwimph2<1 +LEP constraints

⇒ region of theoretical interest The corresponding spin-independent cross-section per nucleon for these models compared to direct detection limits ⇒ Very competitive! Other SUSY models under study

1 year

ANTARES Timeline ANTARES Timeline

Collaboration formed Collaboration formed EO Cable deployed and tested EO Cable deployed and tested Sector Line mechanical test Sector Line mechanical test Sector Line deployment Sector Line deployment Deployment of lines 1 to 10 Deployment of lines 1 to 10 0.1km 0.1km2

2 detector

detector complete complete Site evaluation programme Site evaluation programme to select a suitable site to select a suitable site “Demonstrator” “Demonstrator” line deployment line deployment and operation and operation Technical design report completed Technical design report completed

Sphere Implosion Test Sphere Implosion Test

Stored potential energy in sphere at 2600m: V∆P~ 1 mega Joule !! ⇒ Risk of accidental implosion provoking a catastrophic chain reaction (a la SuperKamiokande) Tests (June 2000) – Two storeys 12m apart, 1 sphere weakened, implosion occurred at a depth of 2600m RESULT:

• Neighbouring spheres on same

storey also imploded

• Electronics in LCM destroyed
• Upper storey intact
• Mechanical cable unbroken

Deployment of Electro Deployment of Electro-

• Optical Cable

Optical Cable

• October 2001 using Castor
• Important milestone

successfully completed

InterLink cable

to shore station

The Sector Line The Sector Line

SCM/SPM, acoustics Rx/Tx LCM+acoustics Rx1 MLCM LCM LCM LCM+acoustics Rx2 floater BSS LED beacon Junction Box Optical module frame Optical Module Local Control Module

100m 100m

The Mini Instrumentation Line The Mini Instrumentation Line

• Current profiler

– ADCP 300 kHz of RDI – Orientated downwards – Current profile for ~150 m – Resolution: ~ 0.5 cm/s – RS232 interface

• Temperature/Salinity:

– Modèle 37-SI MicroCAT – Resolution : 10-4 °C, 10-4 S/m – RS232 interface

• Transmissionmeter

– CSTAR of Wetlabs – Measures over 25cm – Analog response

Sector Line Sector Line -

• Test Deployment

Test Deployment

Test of

• Mechanics
• Deployment
• Instrumentation
• Performed in

November 2001

Line Line Behaviour Behaviour

Summary Summary

R&D phase of ANTARES is finished:

• measurements of sea water properties
• site exploration, implosion tests
• connections of submarine cable
• deployment of demonstrator line

Physics potential:

• detection of point sources of neutrinos
• search for relic neutralinos
• atmospheric neutrino oscillations
• search for completely new phenomena

Construction of 0.1 km2 detector in progress:

• main electro-optical sea cable successfully deployed
• many items ordered, electronics prototyping in progress
• sector line deployment sept 2002
• 10 lines deployed end 2004

First step to future 1km3 detector in Mediterranean Sea

THE END