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Transcript of June 9, 2002 Hallewell ANTARES RICH2002 1 ANTARES : A deep-sea 0.1 km² neutrino telescope Greg...
June 9, 2002Hallewell ANTARES RICH2002
1
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
June 9, 2002Hallewell ANTARES RICH2002
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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
June 9, 2002Hallewell ANTARES RICH2002
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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
June 9, 2002Hallewell ANTARES RICH2002
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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).
June 9, 2002Hallewell ANTARES RICH2002
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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
June 9, 2002Hallewell ANTARES RICH2002
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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
June 9, 2002Hallewell ANTARES RICH2002
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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)
June 9, 2002Hallewell ANTARES RICH2002
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
June 9, 2002Hallewell ANTARES RICH2002
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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
June 9, 2002Hallewell ANTARES RICH2002
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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
June 9, 2002Hallewell ANTARES RICH2002
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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
14
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
June 9, 2002Hallewell ANTARES RICH2002
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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)
June 9, 2002Hallewell ANTARES RICH2002
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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
June 9, 2002Hallewell ANTARES RICH2002
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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.
June 9, 2002Hallewell ANTARES RICH2002
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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
June 9, 2002Hallewell ANTARES RICH2002
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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
June 9, 2002Hallewell ANTARES RICH2002
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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
June 9, 2002Hallewell ANTARES RICH2002
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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
June 9, 2002Hallewell ANTARES RICH2002
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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
June 9, 2002Hallewell ANTARES RICH2002
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
June 9, 2002Hallewell ANTARES RICH2002
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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%
June 9, 2002Hallewell ANTARES RICH2002
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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”
June 9, 2002Hallewell ANTARES RICH2002
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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
June 9, 2002Hallewell ANTARES RICH2002
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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
June 9, 2002Hallewell ANTARES RICH2002
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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
June 9, 2002Hallewell ANTARES RICH2002
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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)