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R. van Dantzig
On behalf of the ANTARES Collaboration
PHYSICS POTENTIAL, PROGRESS,
STATUS
• ANTARES aims• Physics case• R&D studies• The 0.1 km2 detector• Expected performance• Summary
AimsMaster deep-sea technologies• pressure/corrosion resistant equipment• string deployment/recovery• power and data connections
Measure environmental parameters• water (currents, transparency, scattering)• optical background (40K, bioluminescence)• sensitivity loss (sedimentation, bio-fouling)
Design, build, operate ~0.1 km2 deep-sea -detector with attractive scientific programmeprelude to Mediterranean km3 scale
detectorR. van Dantzig, NOW2000, Otranto
Th Physics case (1)
GZK
UHE
R. van Dantzig, NOW2000, Otranto
Cosmic Ray spectrum
beam(p)+dump(p,)
How does the spectrum look like?
Physics case (2)MESSENGERS FROM THE SKY
• Photons !! (but limitations GZK 50 Mpc E>TeV) interaction with matter/radiation/CMB ( --> e+e-)
• protons, nuclei (GZK 50 Mps E > ~50 EeV) interaction with matter/radiation/CMB magnetic deflection (E < ~EeV)
• neutrons (boosted decay length 10 kpc E<~ EeV)
• neutrinos (of all energies)• can cross cosmological distances (weak interactions only)• can point back to their source (no charge, no magnetic deflection)
R. van Dantzig, NOW2000, Otranto
Physics case (3)ASTROPHYSICS & ASTRONOMY point sources (powerful (extra)-galactic objects)
same sky coordinates of several events (AGN, SNR, ..) coincidence in time (GRB)
diffuse flux energy spectrum, sky distribution,flavour composition
COSMOLOGY & DM local sources (Earth, Moon, Sun, galactic center)
indirect search for gravitationally trapped WIMPS (neutralinos)
and topological defects: GUT phase transition remnants
PARTICLE PHYSICS
oscillations (atmo / astro exotics (Dirac monopoles, strangelets, ...)
R. van Dantzig, NOW2000, Otranto
Other talk in this workshop
But, detecting s ... • track)
CC exchange with matter near detector
N cross section increases with E
• HE’s statistically enhanced angle small ( direction ~ -
direction) N spectrum ~ E-2
area/volume: adequate event ratelength: track fitdepth: shield atmospheric
background
area/volume: adequate event ratelength: track fitdepth: shield atmospheric
background
e(pointlike ‘bang’, contained) decay‘double bang’)
Earth: filter: upward going -->
R. van Dantzig, NOW2000, Otranto
Detecting (muon) Neutrinos
Incoming muon-neutrino traverses the Earth (filter), then interacts and produces muon
Incoming muon-neutrino traverses the Earth (filter), then interacts and produces muon
Muon emits Cherenkov radiation (photons) at ~43o in seawater
Muon emits Cherenkov radiation (photons) at ~43o in seawater
Photo-multiplier tube (PMT) in pressure-resistant glass sphere detects photon (arrival time/amplitude)
Photo-multiplier tube (PMT) in pressure-resistant glass sphere detects photon (arrival time/amplitude)
Sky of the antipodesSky of the antipodes
R. van Dantzig, NOW2000, Otranto
History 1996 Start of the ANTARES Collaboration (in
France)
1996–1999 Site exploration (> 30 deployments)
Optical water properties
Biofouling and sedimentation
Optical backgrounds (40K C and bioluminiscence)
1998–1999 Special tests
Mechanics and deployment techniques
Submarine connection
Apr 1999 Proposal & CDR of a 0.1 km2 detector
Nov 1999 Demonstrator string
Large-size demonstrator string deployment and operation
2000 Detailing design, preparations TDR
v
R. van Dantzig, NOW2000, Otranto
R. van Dantzig, NOW2000, Otranto
ANTARES site
90 % of the sky covered
17 % overlap with Amanda
Galactic Center surveyed
R. van Dantzig, NOW2000, Otranto
40 km SE of Toulon
300 x 300 m2
2400 m below sea level
explored with submarine
Optical Water Properties
Absorption length ~ 60m, scattering length > 100m (for large angle scattering)
Optical background40K ~ 65 kHz (10” PMT) bioluminescence: > 200kHz few seconds burstsoverall DT < 5%
Sedimentation negligible
Biofouling < 2%/year for PMT window
R. van Dantzig, NOW2000, Otranto
Conceptual design
2400m2400m
~300m~300m activeactive
Electro-opticElectro-opticsubmarine cablesubmarine cable ~40km~40km
Junction boxJunction box
Readout cablesReadout cables
Shore stationShore station
anchoranchor
floatfloat
Electronics containersElectronics containers
~60m~60mCompass,Compass,tilt metertilt meter
hydrophonehydrophone
Optical moduleOptical module
Acoustic beaconAcoustic beacon
~100m
13 strings, 1000 PMTs12 m between storeys
R. van Dantzig, NOW2000, Otranto
Detector design (1)
R. van Dantzig, NOW2000, Otranto
Detector design (2)
R. van Dantzig, NOW2000, Otranto
10” PMT in17” glass sphere
Electronics in container
ASIC chip (ARS)front-end digitization
DAQ: transmission and selection
Offshore
Full digitization (ASIC chip)Low threshold (~0.3 pe) No (or minimum bias) triggerStar topology networkGigabit Ethernet1Fiber per string to shore
On-shore
Software triggeringLinux farm (~100 PCs)10 ms slice, 1 s processingReliable, flexible, smart triggerFiltering: event rate < 5 kHzAtmospheric muons < 10 Hz
Foreseen:External GRB/SN trigger: all data can be saved for few minutes including last 10 sec before trigger
R. van Dantzig, NOW2000, Otranto
Event reconstruction
Expected resolution
< ~10 TeV
dominated by - angle.
> ~10 TeV < 0.2 - 0.4° (reconstruction error).
E /E 3 (1 TeV E 10 TeV)
E /E 2 (E 10 TeV)
Below E ~ 100 GeV muon range measurement.
Angular resolution Energy resolution
R. van Dantzig, NOW2000, Otranto
Demonstrator string
• Full-scale line (340 m) test of mechanics and deployment
• Partially instrumented: 7 PMTs, CTDs, tiltmeters, positioning system, Slow Controls, etc.
• Read-out via electro-optical cable.
• Operational for several months starting December 1999
R. van Dantzig, NOW2000, Otranto
boat
Mooring line
Real time sonar displayprecision positioning
Compass and tiltmeters
• Taut string at ~2.3º from vertical.
• Tilt stability: ~0.2º over one week (x and y).
• Heading stability: 2º over one week.
Very stable Negligible twist
2 m
Top view
Top
Bottom
Tilt x (°)
100 sec
Top tiltmeter
R. van Dantzig, NOW2000, Otranto
Accoustic positioning
Devices Accuracy ()
Inter-rangemeter < 6 mm
Inter-transponder ~ 1 cm
Range-Transponder
6 cm
4 transponders 3 rangemeters+Sound velocitymeter
Triangulation allows ~5 cm accuracyR. van Dantzig, NOW2000, Otranto
Demonstrator events
• More than 5104 7-fold coincidence events recorded (atmospheric muons)
• Polar angle deduced from depth (z) vs. time pattern with hyperbolic fit (including multimuons).
• 40K filtered out by reconstruction software (see box hit).
z (m
)
ct (m)
z (m
)
ct (m)R. van Dantzig, NOW2000, Otranto
Demonstrator results
Angular distribution agrees with expectations from single + multi-muons
Fit residuals ~ 6 ns
~1100/day reconstructable downgoing ’s (in agreement with MC expectation)R. van Dantzig, NOW2000, Otranto
SummaryANTARES has succesfully performed the planned R&D programme
Site exploration (environmental parameters)
Conceptual design of a 0.1 km2 detector
Detailed tests of components
Verification of undersea connection procedure
Design, deployment, operation of a demonstrator string
Current planning: ~ 0.1 km2 detector to be deployed gradually between 2002 and 2004
Such a detector can be a thorough test-bench for a 1 km3 neutrino telescope in the Mediterranean Sea and have a viable exploratory physics programme.
R. van Dantzig, NOW2000, Otranto
• France• CPPM Marseille
(IN2P3)• DAPNIA-DSM Saclay
(CEA)• IReS, Strasbourg-
Mulhouse• Centre d’Oceanologie
de Marseille• Institut Francais de
Recherche pour l’Exploitation de la Mer (IFREMER)
• INSU-CNRS/IGRAP (Provence)
• Spain• IFIC Valencia
• Russia• ITEP Moscow
• United Kingdom• University of Birmingham• University of Oxford• University of Sheffield
• Netherlands• NIKHEF Amsterdam
• Italy• University of Bari (INFN)• University of Bologna (INFN)• University of Catania (INFN)• LNS (INFN)• University of Rome (INFN)• University of Genova (INFN)
•The ANTARES Collaboration
R. van Dantzig, NOW2000, Otranto