Transcript The dark room sector test bench

ANTARES :
A deep-sea 0.1 km² neutrino
telescope
Greg Hallewell – CPP Marseille
Representing the Antares Collaboration
RICH2002 Workshop on Ring Imaging Cerenkov Detectors, Pylos, Greece, June 5-9, 2002
Hallewell
June 9, 2002
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ANTARES Collaboration


NIKHEF, Amsterdam
University of Sheffield


ITEP, Moscow
IFIC, Valencia
CPPM, Marseille
 DSM/DAPNIA/CEA, Saclay
 C.O.M. Marseille
 IFREMER, Toulon/Brest
 LAM, Marseille
 IReS, Strasbourg
 Univ. de H.-A., Mulhouse
 ISITV, Toulon
Hallewell Observatoire de la Côte d’Azur

University of Bari
 University of Bologna
 University of Catania
 LNS – Catania
 University of Rome
 University of Genova


Universitat Erlangen
June 9, 2002
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Contents
1) Detector Overview
2) Detector Principal Components
3) Site Selected and Ocean Backgrounds
40K,
bioluminescence, light absorption
4) “Demonstrator” Line
7 PMTs, m hyperbolic reconstruction
5) Time and Position Calibration
m reconstruction from PM signals with arrival times known to ~1 ns
acoustic transponder net, LED and laser beacons
6) Sea Instrumentation Line
current profile, salinity, light absorption, P,T, sound velocimeter
7) “Sector” Line Deployment
8) Conculsions
Hallewell
June 9, 2002
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(1.1) Detection Principle
Lattice of 900 PMTs in “Optical Modules”
m track direction from arrival time of light
Neutrino direction:    m   0.7o / E0.6(TeV)
m energy from energy loss and range
Typ. 1g per PMT 40m from m trajectory
Cerenkov
light
isochrone
in seawater
muon
ANTARES
Detector
A 0.1km2 detector should record ~ 1-2000
medium energy cosmic neutrinos
per year (E > 300 GeV).
Hallewell
interaction
neutrino
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(1.2) Scientific Motivation
High Energy
(E > 1 TeV)
Medium Energy
(10 GeV < E < 1 TeV)
neutralino search
 from galactic and extra(signal from annihilating
galactic sources (x-ray
WIMPs in the Earth,
binaries, micro-quasars,
the Sun and the Galaxy)
SNR, AGN, GRB)
Low Energy
(10 GeV < E < 100 GeV)
 oscillations
(observation of first
oscillation minimum
from atmospheric )
+Oceanography
Hallewell
- measurements of oceanographic parameters of the deep sea
- studies of bioluminescence
June 9, 2002
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0.1 km² Detector : Expected performance
Angular resolution
 Including effects of reconstruction and
selection, PMT TTS, positioning, timing
calibration accuracy and scattering.
 Below ~10 TeV angular error is
dominated by -m physical angle.
 Above ~10 TeV angular accuracy is
better than 0.4° (reconstruction error).
Hallewell
Energy resolution
E /E  3 (E 1 TeV)
 Below E ~ 100 GeV energy
estimation via muon range
measurement.
June 9, 2002
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2400m
ANTARES 0.1km2 detector
12 m
Optical
Module
triplet
Time
calibration
LED Beacon
(1 / sector)
Local
electronics
Hydrophone
(1 / sector)
60 m
Hallewell
• 10 lines of 90 PMTs
• 6 sectors/line (350m)
• 5 storeys/sector (60m)
• 3 PMTs/storey (12m)
40 km cable
to shore
350 m
100 m
Junction
box
Readout cables
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(2) Principal Components: A Detector Line
Buoy
90 PMTs/line
6 sectors of
5 storeys of
3 PMTs
Electro-mechanical Cable
- mechanical support (kevlar core)
with optical fibres and power conductors
LED Beacon (4 per line)
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)
Master Local Control Module:
- acoustic positioning (1 hydrophone / sector)
- data acquisition: 5 storeys  sector ethernet 1Gb/s
12m
100m
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
Hallewell
Sea bed
Bottom String Structure
- acoustic string release, acoustic positioning transponder
June 9, 2002
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(2.1) Principal Components: Optical Module & PM
LED pulser
Optical gel
Photomultipler: 10” Hamamatsu R7081-20
Sensitive area > 500 cm2;
14 stages; 2.108 Gain @ 2500V;
Transit Time:
Quantum
Efficiency
typ 60ns @
1750V (–2.5ns/100V)
(Regularly Measured by LED pulser on each
Latt(Spher
Latt(Gel):
tube)
e)
cm
Transit Time
Spread:
(LoBoro):
cm 1.3 ns(spec.):V fixed;
Dark Count Rate (0.3 pe equ. Thr.): < 10kHz;
Glass
Hallewell
sphere (Nautilus)
Active (C-W) PMTPulse Shape:
Base (ISEG) Rise TimeMu
metal
magnetic
< 5 ns,
FWHM
< 12
ns shield
June
9, 2002
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Some Detector Specificatons
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 OM
LED Pulser in each OM, LED & Laser beacons:Goal < 0.5 ns
Hallewell
June 9, 2002
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(2.3) ARS Timing Resolution (May ’02)
Timing Resolution:
electronic signals
directly into ARS
Timing Resolution:
attenuated laser
signals  OM ARS
Hallewell
June 9, 2002
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(3) The ANTARES Site
Antares Site:
40Km SE Toulon
(42º50’N, 6º10’E)
Depth 2400m
Shore Base
La Seyne-sur-Mer
40 km
Submarine cable
-2400m
Hallewell
June 9, 2002
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(3.2) Site: Sea Floor Layout, Vehicle Resources
Site inspection:
“Cyana”
(Manned Submersible)
Line sea floor
configuration
1
Line connections
Victor (ROV)
2
6
5
3
4
10
9
7
8
13
14
11
12
Wet-Mateable Connector
(@250 bar H2O)
At Line Sea Anchor
Submarine cable:
ALCATEL
Hallewell
June 9, 2002
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(3.4) Water optical properties: Transparency
Variable distance
between
LED and PMT
“ascenseur”
Season
[473nm] [375nm]
labs (m)
Lscatt 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  3
305  31
July 99
22.0  0.1
22.0  0.1
104  52
102  16
Sept 99
25.1  0.2
25.4  0.2
120  2
108  3
June 00
28.0  0.1
28.0  0.1
134  2
124  3
Need in-situ on line monitoring (instrumentation line)
Hallewell
June 9, 2002
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(3.5) Water Properties: Optical Backgrounds
(1) Cerenkov Light:
from Atmospheric (Downgoing) m’s
(~400 g cm-1: 300<l<600 nm)
( <Em ~350 GeV: m rate 10-30 Hz)
(106 * rate of upgoing m from 
(2) Sea Optical background:
~ 60 kHz on 10” PMT mainly 40K
Bottom Currents Measured
 typ. < 5% dead time/ PMT
Bioluminescence
bursts (o~MHz), locally-correlated
(typ 1 storey, 3 PMTs)
~ few % of the time
+ Bottom Current Dependent
Hallewell
June 9, 2002
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(4) Full 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 electrooptical cable
– 50,000 atmospheric m’s reconstructed

December 98 : successful undersea electrical
connection test of detector anchor performed at
2400m depth by IFREMER submarine vehicle “Nautile”
(ex-Titanic expeditions)
Hallewell
June 9, 2002
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(4.1) Muons on “Demonstrator line”
• 50,000 events with 7-fold coincidences
(>1300 reconstructed events per day)
• Zenith from 4 par. Hyperbolic fit of depth
vs. PMT signal timestamp
No reconstructed
events  < 45º
• 40K hits filtered out by software
• MC agrees with data (multimuons, ghosts)
Hallewell
June 9, 2002
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(5.1) 40-60 kHz Acoustic positioning system
1 of 3 rangemeters
4 transponders
134.1
Devices
Accuracy ()
Inter-rangemeter
~1 cm
Inter-Transponder
~ 1 cm
Rang.-Transponder
 3 cm
Hallewell
YD3 (m)
Self-Cal.
Y coord. Range 3-2 (m)
mesures
interpolation
134.05
134
133.95
133.9
5cm
133.85
133.8
0
10
20
30
40
50
temps (min)
Require Positioning Accuracy < 1 ns (1 ns = 22cm in seawater).
Triangulation allows  5 cm accuracy
60
70
80
Time (min)
90
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(6) The Sector Line: Deployment for late ‘02
Buoy
Optical
Module
LCM+acoustics Rx2
Local Control
Module
LCM
LCM
LED beacon
MLCM
Optical module
frame
LCM+acoustics Rx1
SCM/SPM,
acoustics Rx/Tx
Junction
Box
InterLink cable
BSS
Hallewell
to shore station
June 9, 2002
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(7) The Mini Instrumentation Line

Mechanical
Cable
Current profiler
– ADCP 300 kHz of RDI
Sound
Velocimeter
– Orientated downwards
– Current profile for ~150 m depth
ADCP
Current
Profiler
– Resolution: ~ 0.5 cm/s
– RS232 interface

Electro Mechanical Cable
3 fibres for DAQ
Temperature/Salinity:
100m
– Model 37-SI MicroCAT
-4
Acoustic Positioning
Modules (receivers)
-4
– Resolution : 10 °C, 10 S/m
– RS232 interface

Transmissionmeter
CTD
Optical
Beacon
CSTAR
– CSTAR of Wetlabs
– Measures over 25cm
•
large azimuthal range for labs, lscatt
JB
Hallewell
Electro Mechanical Cable
2 fibres for DAQ, 1 for clock
2 fibres for DAQ
1 for clock
LASER
Beacon
100m
Acoustic
Positioning
Modules
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ANTARES Timeline
Collaboration formed
Site evaluation programme
to select a suitable site
“Demonstrator”
line deployment
and operation
Deployment of lines 1 to 10
Sector Line deployment
Sector Line mechanical test
EO Cable deployed and tested
Technical design report completed
Hallewell
0.1km2 detector
to complete
June 9, 2002
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(8) Conclusion
ANTARES 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
Hallewell
Major step forward towards a km-scale
neutrino telescope in the Mediterranean
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THE END
(possible extras follow)
Hallewell
June 9, 2002
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Angular 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
Hallewellerrors, at low energy by the angle between the muon and neutrino
June 9, 2002
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(2.1) Principal Components: Optical Module
LED pulser
Optical gel
Photomultipler: 10” Hamamatsu R7081-20
Glass
Hallewell
sphere (Nautilus)
Active (C-W) PMT
Base (ISEG)
Mu metal magnetic
Juneshield
9, 2002
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(2.2) Principal Components: Hamamatsu
R7081-20
Characteristics
Sensitive area > 500 cm2;
14 stages; 2.108 Gain @ 2500V;
Transit Time:
typ 60ns @ 1750V (–2.5ns/100V)
Quantum Efficiency
(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;
Latt(Sphere)
(LoBoro): cm
Latt(Gel): cm
T > 88%
Pulse Shape:
Rise Time < 5 ns, FWHM < 12 ns
Hallewell
June 9, 2002
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7 Mb/s
OM
LCM
OM
OM
LCM
LCM
MLCM
LCM
SCM
750 Mb/s
“Local Control
Module”
25 Mb/s
(2.4) Data Flow Architecture
OFFSHORE
• Communication between offshore LCM processors (MPC8xx)
“Master (sector) and onshore farm (~100 PCs) using Ethernet protocol via
Local Control
optical fibres
Module”
• All data to shore- if bandwidth saturated, an OFFSHORE
TRIGGER can be activated to reduce dataflow to just local
125 Mb/s
coincidences
• Bandwidth of data transmission maximised using DWDM
“String Control
Dense Wavelength Division Multiplexing
Module”
- Each sector of a string assigned a colour (7 colours/string)
- At SCM all colours multiplexed to one pair of fibres
JB
from other lines
7.5 Gb/s
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
Hallewell
hits
DWDM
DWDM
125 Mb/s
Ethernet Switch
75 kb/s
75 Mb/s
CPU
7.5 Mb/s
DataWriter
June 9, 2002
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Energy Resolution





Hallewell
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, 2002
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(5.2) Optical Beacons
for timing calibration precision 0.5 ns:
cf 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  8.107g per pulse @ 470nm,
Trise 1.82 ns; FWHM 4.56.5 ns
Green Laser Beacon (Instrumentation line anchor)
(illuminates lower stories of most lines):
Fast pin diode for time reference
Nanolase NG-10120-120 laser head + Diffuser
532 nm; 1 mJ/pulse, Trise 1.82 ns; FWHM 0.8 ns
Hallewell
June 9, 2002
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(3) The ANTARES Site
Antares Site:
40Km SE Toulon
(42º50’N, 6º10’E)
Depth 2400m
Shore Base
La Seyne-sur-Mer

3.5 sr of sky covered

0.5 sr overlap with Amanda

Galactic Centre surveyed
Need neutrino telescopes in
Hallewell both hemispheres
40 km
Submarine cable
-2400m

June 9, 2002
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(3.4) Water optical properties: Transparency
Variable distance
between
LED and PMT
“ascenseur”
Season
[473nm] [375nm]
labs (m)
Lscatt 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  3
305  31
July 99
22.0  0.1
22.0  0.1
104  52
102  16
Sept 99
25.1  0.2
25.4  0.2
120  2
108  3
June 00
28.0  0.1
28.0  0.1
134  2
124  3
Need in-situ on line monitoring (instrumentation line)
Hallewell
June 9, 2002
34
Water Transparency
labs ~ 55-65 m ;
lscat > 100 m
at large angles
Hallewell
June 9, 2002
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