June 9, 2002 Hallewell ANTARES RICH2002 1 ANTARES : A deep-sea 0.1 km² neutrino telescope Greg Hallewell – CPP Marseille Representing the Antares Collaboration

June 9, 2002Hallewell ANTARES RICH2002

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ANTARES :ANTARES : A deep-sea 0.1 km² A deep-sea 0.1 km² neutrino telescopeneutrino telescope

Greg Hallewell – CPP Marseille

Representing the Antares Collaboration

RICH2002 Workshop on Ring Imaging Cerenkov Detectors, Pylos, Greece, June 5-9, 2002


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ANTARES Collaboration

University of Sheffield

CPPM, Marseille DSM/DAPNIA/CEA, Saclay C.O.M. Marseille IFREMER, Toulon/Brest LAM, Marseille IReS, Strasbourg Univ. de H.-A., Mulhouse ISITV, Toulon Observatoire de la Côte d’Azur

University of Bari University of Bologna University of Catania LNS – Catania University of Rome University of Genova

IFIC, Valencia

NIKHEF, Amsterdam

ITEP, Moscow

Universitat Erlangen


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ContentsContents

1) Detector Overview2) Detector Principal Components3) Site Selected and Ocean Backgrounds

40K, bioluminescence, light absorption

4) “Demonstrator” Line7 PMTs, hyperbolic reconstruction

5) Time and Position Calibration reconstruction from PM signals with arrival times known to ~1 nsacoustic transponder net, LED and laser beacons

6) Sea Instrumentation Linecurrent profile, salinity, light absorption, P,T, sound velocimeter

7) “Sector” Line Deployment8) Conculsions


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neutrino

muon Cerenkov

light isochrone

in seawater

ANTARESDetector

interaction

Lattice of 900 PMTs in “Optical Modules” track direction from arrival time of light Neutrino direction: 0.7o / E0.6(TeV) energy from energy loss and range Typ. 1 per PMT 40m from trajectory

(1.1) Detection Principle(1.1) Detection Principle

A 0.1km2 detector should record ~ 1-2000 medium energy cosmic neutrinos

per year (E > 300 GeV).


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Low Energy (10 GeV < E < 100 GeV)

Medium Energy

(10 GeV < E < 1 TeV)High Energy

(E > 1 TeV)

oscillations (observation of first

oscillation minimum from atmospheric )

neutralino search(signal from annihilating

WIMPs in the Earth, the Sun and the Galaxy)

from galactic and extra-galactic sources (x-ray

binaries, micro-quasars, SNR, AGN, GRB)

(1.2)(1.2) Scientific MotivationScientific Motivation

+Oceanography - measurements of oceanographic parameters of the deep sea- studies of bioluminescence


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0.1 km² Detector0.1 km² Detector : Expected performance : Expected performance

Including effects of reconstruction and selection, PMT TTS, positioning, timing calibration accuracy and scattering.

Below ~10 TeV angular error is dominated by - physical angle.

Above ~10 TeV angular accuracy is better than 0.4° (reconstruction error).

E /E 3 (E 1 TeV)

Below E ~ 100 GeV energy estimation via muon range measurement.

Angular resolutionAngular resolution Energy resolutionEnergy resolution


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ANTARES 0.1km2 detector

60 m

• 10 lines of 90 PMTs• 6 sectors/line (350m)

• 5 storeys/sector (60m)

• 3 PMTs/storey (12m)

350 m

100 m

12 m

Junctionbox

Readout cables

40 km cableto shore

2400m

Local electronics

Optical

Module

triplet

Hydrophone (1 / sector)

Time calibration

LED Beacon

(1 / sector)


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(2) Principal Components: A Detector (2) Principal Components: A Detector LineLineBuoy

Electro-mechanical Cable - mechanical support (kevlar core)

with optical fibres and power conductors

3 Optical Modules/storey- 10” PMT, active base, LED internal calibration system 1 Local Control Module; -“ARS” front end ASIC (amplitude, 1GHz time sampling)/PMT;-Tiltmeter (line shape in current) & compass (line torque)

Sea bedBottom String Structure - acoustic string release, acoustic positioning transponder

String Control/Power Module: - string power supplies - data acquisition: 6 sectors DWDM 6x1Gb/s on 1 fibre

Interlink cable, - wet-mateable connector: 4 optofibres+ 2 power conductors

12m

100m

90 PMTs/line6 sectors of 5 storeys of3 PMTs

Master Local Control Module: - acoustic positioning (1 hydrophone / sector) - data acquisition: 5 storeys sector ethernet 1Gb/s

LED Beacon (4 per line)


9Glass sphere (Nautilus)

Photomultipler: 10” Hamamatsu R7081-20

Mu metal magnetic shield Active (C-W) PMT

Base (ISEG)

(2.1) Principal Components: (2.1) Principal Components: Optical Module & Optical Module & PMPM

LED pulser Optical gel

Quantum Efficiency

Latt(Sphere)

(LoBoro):

cm

Latt(Gel): cm

Sensitive area > 500 cm2;

14 stages; 2.108 Gain @ 2500V;

Transit Time: typ 60ns @ 1750V (–2.5ns/100V)(Regularly Measured by LED pulser on each tube)Transit Time Spread: 1.3 ns(spec.):V fixed;

Dark Count Rate (0.3 pe equ. Thr.): < 10kHz;

Pulse Shape:Rise Time < 5 ns, FWHM < 12 ns


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Cerenkov signature: Timing of cone arrival at PMTs on strings: hyperbolic fit PMT positions need to be known to ~20 cm (1 ns in seawater)

# OM hits depends on range of muon

Detector Positioning Resolution Hits to <1 ns to be small compared with dispersive limits in seawater of ~ 1.6 ns over ~ 40 m optical path length

achieved by: acoustic transponder net: string profile in undersea current,

inclinometers (pitch, yaw) & compasses (heading: OM rotation angle around string ): (1 per “storey”)

Timing Resolution on OMLED Pulser in each OM, LED & Laser beacons:Goal < 0.5 ns

Some Detector Specificatons


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(2.3) ARS Timing Resolution (May (2.3) ARS Timing Resolution (May ’02)’02)

Timing Resolution:

electronic signals directly into ARS

Timing Resolution: attenuated laser

signals OM ARS


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(3) The ANTARES Site(3) The ANTARES Site

Antares Site:40Km SE Toulon(42º50’N, 6º10’E)Depth 2400m

Shore BaseLa Seyne-sur-Mer

-2400m

40 km

Submarine cable


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1

5

3

2

4

6

9

7 8

10

13

11 12

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Submarine cable: ALCATEL

Site inspection:“Cyana”

(Manned Submersible)

(3.2) Site: Sea Floor Layout, Vehicle Resources

Line sea floor configuration Line connections

VictorVictor (ROV)

Wet-Mateable Connector (@250 bar H2O)

At Line Sea Anchor


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Variable distance between

LED and PMT “ascenseur”

((3.43.4) Water optical properties: ) Water optical properties: TransparencyTransparency

Season[473nm] [375nm] abs (m) scatt eff (m)

July 98 69 1 272 4

March 99 61 1 231 11

June 00 49.7 0.3 48.4 0.3

294 3305 31

July 99 22.0 0.122.0 0.1

104 52102 16

Sept 99 25.1 0.225.4 0.2

120 2108 3

June 00 28.0 0.128.0 0.1

134 2124 3

Need in-situ on line monitoring (instrumentation line)


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(3.5) Water Properties: Optical Backgrounds(3.5) Water Properties: Optical Backgrounds

(1) Cerenkov Light:

from Atmospheric (Downgoing) ’s (~400 cm-1: 300<<600 nm)

( E ~350 GeV: rate 10-30 Hz)

(106 * rate of upgoing from

(2) Sea Optical background:

~ 60 kHz on 10” PMT mainly 40K

Bioluminescence

bursts (o~MHz), locally-correlated (typ 1 storey, 3 PMTs) ~ few % of the time

+ Bottom Current Dependent

Bottom Currents Measured typ. < 5% dead time/ PMT


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(4) Full (4) Full Demonstrator Line (’98-’00)Demonstrator Line (’98-’00) First (350m) line equipped with 16 pairs of Glass Spheres

– Summer 98 : successful deployment test at 2300m depth performed with Dynamical Positioning ship

– December 99-June 00 : demonstrator equipped with 7 PMTs + acoustic positioning system linked to shore station by electro-optical cable

– 50,000 atmospheric ’s reconstructed

December 98 : successful undersea electrical connection test of detector anchor performed at 2400m depth by IFREMER submarine vehicle “Nautile” (ex-Titanic expeditions)


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• 50,000 events with 7-fold coincidences

(>1300 reconstructed events per day)

• Zenith from 4 par. Hyperbolic fit of depth vs. PMT signal timestamp

• 40K hits filtered out by software

• MC agrees with data (multimuons, ghosts)

(4.1) Muons on “Demonstrator (4.1) Muons on “Demonstrator line”line”

No reconstructe

d

events < 45º


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(5.1) 40-60 kHz Acoustic positioning (5.1) 40-60 kHz Acoustic positioning systemsystem

~ 1 cmInter-Transponder

3 cmRang.-Transponder

~1 cmInter-rangemeter

Accuracy ()Devices

4 transponders1 of 3 rangemeters

0 10 20 30 40 50 60 70 80 90133.8

133.85

133.9

133.95

134

134.05

134.1

temps (min)

YD

3 (

m)

mesures interpolation

Time (min)

5cmY

coord

. R

an

ge 3

-2 (

m)

Require Positioning Accuracy < 1 ns (1 ns = 22cm in seawater).Triangulation allows 5 cm accuracy

Self-Cal.


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InterLink cable

to shore station

(6) The Sector Line: Deployment for late (6) The Sector Line: Deployment for late

‘02‘02

SCM/SPM, acoustics Rx/Tx

LCM+acoustics Rx1

MLCM

LCM

LCM

LCM+acoustics Rx2

Buoy

BSS

LED beacon

Junction Box

Optical moduleframe

Optical Module

Local Control Module


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100m

100m

SoundVelocimeter

ADCPCurrent Profiler

CTD CSTAR

Acoustic Positioning

Modules (receivers)

Optical Beacon

Acoustic PositioningModules

LASER Beacon

(7) The Mini Instrumentation Line(7) The Mini Instrumentation Line

Electro Mechanical Cable2 fibres for DAQ, 1 for clock

Electro Mechanical Cable3 fibres for DAQ

Mechanical Cable

JB 2 fibres for DAQ1 for clock

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

Temperature/Salinity: – Model 37-SI MicroCAT

– Resolution : 10-4 °C, 10-4 S/m

– RS232 interface

Transmissionmeter – CSTAR of Wetlabs– Measures over 25cm

• large azimuthal range for abs, scatt


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ANTARES TimelineANTARES TimelineCollaboration formedCollaboration formed

EO Cable deployed and testedEO Cable deployed and testedSector Line mechanical testSector Line mechanical test

Sector Line deploymentSector Line deployment

Deployment of lines 1 to 10Deployment of lines 1 to 10

0.1km0.1km22 detector detectorto completeto complete

Site evaluation Site evaluation programme to select a programme to select a suitable sitesuitable site

““Demonstrator” Demonstrator” line deployment line deployment and operationand operation

Technical design report completedTechnical design report completed


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(8) Conclusion(8) ConclusionANTARES has made excellent progress over the past 4 years :

– Site environmental characterisation OK– Tests of marine technologies under control– Deployment and operation of Demonstrator String– Down-going muons reconstructed in demonstrator– Expanding Collaboration

ANTARES has entered Phase II of its programme : the design, the installation and commissioning

of a 10-string 0.1 km² detector in 2002-2004 -main electro-optical sea cable successfully deployed

- sector line deployment Sept 2002

Major step forward towards a km-scale neutrino telescope in the Mediterranean


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THE END(possible extras follow)


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Angular ResolutionAngular Resolution

The angular resolution of the detector depends on – reconstruction

algorithms– selection

programs– timing accuracy

(PMT timing error, positional error on OMs, timing calibration error)

Above 10 TeV the neutrino pointing accuracy is 0.4 degrees or better including scattering effects

Note: at high energy the error is dominated by reconstruction errors, at low energy by the angle between the muon and neutrino


28Glass sphere (Nautilus)

Photomultipler: 10” Hamamatsu R7081-20

Mu metal magnetic shield Active (C-W) PMT

Base (ISEG)

(2.1) Principal Components: (2.1) Principal Components: Optical Optical ModuleModule

LED pulser Optical gel


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(2.2) Principal Components: (2.2) Principal Components: Hamamatsu Hamamatsu

R7081-20 R7081-20 CharacteristicsCharacteristics

Sensitive area > 500 cm2;

14 stages; 2.108 Gain @ 2500V;

Transit Time: typ 60ns @ 1750V (–2.5ns/100V)(Regularly Measured by LED pulser on each tube)Transit Time Spread:

1.3 ns(spec.):V fixed;

Dark Count Rate (threshold 0.3 pe equ.): < 10kHz;

Pulse Shape:Rise Time < 5 ns, FWHM < 12 ns

Quantum Efficiency

Latt(Sphere) (LoBoro): cm

Latt(Gel): cm

T > 88%


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(2.4) Data Flow Architecture(2.4) Data Flow ArchitectureOFFSHORE • Communication between offshore LCM processors (MPC8xx) and onshore farm (~100 PCs) using Ethernet protocol via optical fibres• All data to shore- if bandwidth saturated, an OFFSHORE TRIGGER can be activated to reduce dataflow to just local coincidences• Bandwidth of data transmission maximised using DWDM Dense Wavelength Division Multiplexing - Each sector of a string assigned a colour (7 colours/string) - At SCM all colours multiplexed to one pair of fibres

ONSHORE •The colours of each line are demultiplexed• All data of current time frame (10ms) assigned to single CPU• Each PCs run the DataFilter program which accepts events with time correlated hits

LCM

LCM

LCM

MLCM

LCM

OM

OM

OM

7 Mb/s

25 Mb/s

SCM

125 Mb/s

750 Mb/s

7.5 Mb/s75 Mb/s 75 kb/s

125 Mb/s

DWDM DWDM

CPU DataWriter

Ethernet Switch

7.5 Gb/s

from other linesJB

“Local Control Module”

“Master (sector) Local Control

Module”

“String Control Module”


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Energy ResolutionEnergy Resolution

Different techniques are used in different energy regimes

Below 100 GeV the energy can be estimated from the range of the muon: E ~ 3 GeV

Use of the hadronic shower energy may improve energy resolution at medium and low E

At energies above 1 TeV the muon energy loss is dominated by catastrophic energy loss (bremss., pair production) which increases with energy. A truncated mean parametrization is used

The corresponding energy resolution is typically a factor of 3 to 4 for E > 1 TeV


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(5.2) Optical Beacons(5.2) Optical Beacons for for timing calibration precision 0.5 ns:timing calibration precision 0.5 ns:cf arrival time precision of OM ~ 1 nscf arrival time precision of OM ~ 1 ns

LED (Blue) Beacon (4 per line )(illuminates several stories of neighboring lines): MiniPMT for time reference LED pulsers 5.106 8.107 per pulse @ 470nm,

Trise 1.82 ns; FWHM 4.56.5 ns

Green Laser Beacon (Instrumentation line anchor)(illuminates lower stories of most lines): Fast pin diode for time referenceNanolase NG-10120-120 laser head + Diffuser

532 nm; 1 J/pulse, Trise 1.82 ns; FWHM 0.8 ns


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(3) The ANTARES Site(3) The ANTARES Site

Antares Site:40Km SE Toulon(42º50’N, 6º10’E)Depth 2400m

Shore BaseLa Seyne-sur-Mer

-2400m

40 km

Submarine cable

3.5 sr of sky covered

0.5 sr overlap with Amanda

Galactic Centre surveyed

Need neutrino telescopes in both hemispheres


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Variable distance between

LED and PMT “ascenseur”

((3.43.4) Water optical properties: ) Water optical properties: TransparencyTransparency

Season[473nm] [375nm] abs (m) scatt eff (m)

July 98 69 1 272 4

March 99 61 1 231 11

June 00 49.7 0.3 48.4 0.3

294 3305 31

July 99 22.0 0.122.0 0.1

104 52102 16

Sept 99 25.1 0.225.4 0.2

120 2108 3

June 00 28.0 0.128.0 0.1

134 2124 3

Need in-situ on line monitoring (instrumentation line)


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abs ~ 55-65 m ;scat > 100 mat large angles

Water Water TransparencyTransparency

Documents

June 9, 2002 Hallewell ANTARES RICH2002 1 ANTARES : A deep-sea 0.1 km² neutrino telescope Greg Hallewell – CPP Marseille Representing the Antares Collaboration