First data of ANTARES neutrino telescope

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First data of ANTARES neutrino telescope
The 3rd International Workshop on THE HIGHEST
ENERGY COSMIC RAYS AND THEIR SOURCES May 16-18
2006, INR-Moscow, Russia

• Francisco Salesa Greus
• IFIC (CSICUniversitat de València, Spain)
• On behalf of the ANTARES collaboration

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Cosmic Ray spectrum
GZK cut-off end of the cosmic ray spectrum??

• Cosmic Rays bombard us from anywhere beyond our
  atmosphere, with a very wide energy spectrum.

SNR origin
Galactic origin (several theories)
AGN, top-down models??
1 particle per m2 per second.
1 particle per m2 per year.
1 particle per km2 per year.
Extra-galactic origin
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Neutrino connection
High energy Cosmic Ray flux can constrain
neutrino fluxes (Waxman-Bachall limit).
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Physic topics

• Neutrino Astrophysics

AGN
SNR
GRB
Extragalactic sources
Galactic sources

• Dark matter annihilation of neutralinos in
  massive objects (Sun, Galactic Centre,)
• Neutrino oscillations atmospheric neutrino
  angular distribution.
• Monopoles, top-down models, etc.
• Other scientific topics Biology, Oceanography,
  etc.

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Detection principle

• HE neutrino from extraterrestrial sources
  interacts in a CC reaction with the surrounding
  media.

Cosmic accelerator
Earth
? reach the detector, not deflected
? absorbed by matter and EBL
CMB
p deflected by magnetic fields, GZK effect

• A muon is produced which induces Cherenkov light
  emission.

• Light Cherenkov is recorded by an array of PMTs.

nm N -gt m X

• Around 100 photons are emitted in 1 cm of flight
  path for blue-UV wavelength, where absorption
  in water and PMT efficiency are maximal.

m
n
1.2 TeV muon traversing the detector
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Physical background

• Two muon backgrounds

• Atmospheric muons. Flux reduced due to detector
  depth. Background exclusion selecting only
  up-going events.

• Muons induced by atmospheric neutrinos.
  Background rejection on the basis of energy
  spectrum.

p
The atmospheric m flux is 6 orders of magnitude
higher than the flux induced by natm.
?
?
?
p
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ANTARES collaboration
Submarine cable
21 Institutions from 6 European countries

• ANTARES detector located 40 km off Toulon coast
  (42º50N 6º10E) at 2500 metres depth.

• A submarine cable links with the shore station
  placed at La Seyne sur Mer.

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The ANTARES detector
Storey
Buoy
40 km electro-optical cable to shore
350 m
12 lines 25 storey/line 3 PMT/storey 900 PMTs in
total
Junction box
100 m
Submersible
12 lines 3x25 PMT/line
Interlink cable
60-75 m
Anchor(BSS)
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The ANTARES devices
The Storey
The LED Beacon for time calibration purposes.
The ANTARES 10 PMT is housed in the Optical
Module. A glass sphere protects it from high
pressures. A µ-metal cage shields against the
Earth magnetic field.
The Local Control Module houses, in a titanium
frame, the electronic cards devised for the
readout of the three OMs .
The Hydrophone (Rx) for positioning.
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The ANTARES devices

• A 40 km electro-optical cable links the shore
  station and the detector.
• With 58 mm diameter, it is made up of 48 monomode
  pure silica fibre optics.
• It provides the power and clock commands signal
  to the junction box.

• Junction box made up of titanium, splits the
  clock and commands signals to the BSS of each
  line.
• The BSS anchors the line and controls the power
  and data transmission. It also contains some
  instruments as a pressure sensor or RxTx
  hydrophone.

BSS
Junction box
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Time calibration

• An internal LED monitors the transit time of the
  PMT.

• The Optical beacons are external light sources
  for timing calibration

The Laser beacon emits at 532 nm and is placed at
the anchor of the MILOM.
The LED beacon, emits blue light (472 nm) from 36
pulsed LEDs. Four beacons are placed along each
line.

• All the OMs are illuminated by OB. The time
  off-sets measured in the laboratory can be
  checked in-situ.

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Positioning

• The positioning system consists of an acoustic
  system, compasses and tiltmeters.
• The acoustic system uses sound signals in the
  40-60 kHz range.
• The tiltmeters provide the pitch and roll. The
  compasses, the magnetic field and heading.

Roll
Pitch
Autonomous Pyramid
Fixed RxTx (transponder hydrophones) located in
each BSS.
In addition, 3 autonomous transponder pyramids
are also fixed at the sea bed and located around
the detector strings.
BSS

• Five Rx (receiving hydrophones) distributed in
  each line.
• One tiltmeter-compass card per storey.

Electro-optical cable to shore
The Positioning System provides 10 cm accuracy
for each OM.
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Detector performance

• Effective area

• Angular resolution

• Effective area means the area of 100 efficient
  flat surface.
• Depends on the incident neutrino flux.
• Muon effective area is the relevant quantity to
  compare between experiments.
• The maximum area is reached at 10-100 TeV.
• At high energies the Earth becomes opaque to
  neutrinos.

mrec, ntrue mrec, mtrue
m
q
n
reconstruction
kinematics

• Below 10 TeV is dominated by the kinematic angle
  qmu.
• Over 10 TeV dominated by reconstruction
  (calibration, electronics, etc.)

Earth opacity effect.
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Point-like source candidates
Galactic centre
SNR RX J1713-3946
TeV sources candidates.
Vela pulsar

• ANTARES will observe 3p sr (galactic centre
  visible 67 of the time).
• Complementary to AMANDA/IceCube at the South Pole
  (0.6p sr overlap).
• HESS observations of RX J1713-3946 SNR spectrum
  show a presumably hadronic scenario, thus
  neutrino emission is expected (Nature 432 (2004)
  75).

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Source detection

• Diffuse flux detection.

• Point-like source detection.

• Experimental limits for different experiments
  assuming E-2 spectrum.

• Comparison between experiments for point-like
  sources detection.

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Collaboration milestones schedule
RD

• 1996-1999 RD and site evaluation period.

• November 1999 summer 2000 prototype lines
• October 2001 Electro-optical cable deployment.
• December 2002 Junction box (JB) connection.
• December 2002 PSL (Prototype Sector Line)
  deployment.
• February 2003 MIL (Mini Instrumentation Line).
• March 2003 MIL PSL connection to JB.
• May and July 2003 MIL PSL recovering.

PROTOTYPES

• March 2005 Line0 (test of mechanics) MILOM
  (Mini Instrumentation Line with Optical Modules)
  deployment.
• April 2005 MILOM connection.
• May 2005 Line0 recovering.
• February 2006 Line1 deployment.
• March 2006 Line1 connection (Data analysis of
  Line 1 in progress).

FINAL DESIGN

• Line 2 deployment foreseen by July 2006.
• Lines 3 and 4 before the end of this year.
• The whole detector will by finished by end 2007.
• Science operation from 2007.

FUTURE
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Site evaluation results
measured with pulsed LEDs

• Water properties.

• Optical background.

• Biofouling.

Continuous component due to 40K decay (salt) and
bacteria colonies. Burst (20 over baseline) due
to bioluminiscense abyssal creatures.
At 90º a global loss of 1.5 is expected in one
year with a saturation tendency.
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MILOM line

• Instrumentation line OMs

MILOM sketch

• 3 Storeys.

• 4 OMs.

• 2 LED Beacons.
• 1 Laser beacon.

• 1Rx hydrophone.
• 1RxTx transponder.

• Sound velocimeter.
• Seismometer.
• Acoustic Doppler Current Profiler.
• Conductivity Temperature probe.

• Successfully test of DAQ and electronics.
• MILOM is still operating.

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Results from MILOM

• Site properties

summer
autumn
Bursts
120 kHz
Baseline
60 kHz
Seasonal variations
Example of data taking rate
Baseline evolution with time
Correlation with currents has been noticed
Currents lt 20 cm/s 5 cm/s on average
Water current velocity evolution with time
Heading of the three MILOM storeys
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Results from MILOM

• Spatial Calibration

• Charge Calibration

WF signal example.
Distance from autonomous line (RxTx) to MILOM
RxTx, evolution with time.
96 m
175 m
Evolution with time of the normalized charge.
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Results from MILOM

• Time Calibration

The rate measured of these coincidences is 13 Hz
which is in agreement with the estimations.
Internal LED Dt evolution with time
40K coincidences between OMs.
Storey
OM signal beacon PMT time difference for each
OM.
MILOM LED beacon
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Line 1 deployment
25 storeys 1 BSS
LED beacon
RxTx
Buoy
OM
Line anchor
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Line 1 deployment
March 2006
February 2006
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First muons reconstructed with Line 1
Antares preliminary
Antares preliminary
Antares preliminary
Result of Fit

• Run / Event
• Zenith angle
• Fit probability

• 21240 / 12505
• q 101o
• P(c2,ndf) 0.88

• 21240 / 12527
• q 172o
• P(c2,ndf) 0.94

• 21240 / 12845
• q 72o
• P(c2,ndf) 0.37

z m

• Triggered hits
• Hits used in fit
• Snapshot hits

t ns
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Atmospheric Muon Bundles
Montecarlo
Reconstruction
Antares preliminary
Antares preliminary
Time residuals s 7.8 ns
Time residuals s 7.8 ns
Number of events arbitrary units
Number of events arbitrary units
Dt ns
Dt ns
Antares preliminary
Antares preliminary
Number of events arbitrary units
Number of events arbitrary units
P(c2,ndf)
P(c2,ndf)
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Line 1 calibration
Line 1
s 2.6 ns
MILOM LED Optical Beacon
150 m
Number of events arbitrary units
s 0.7 ns
70 m
Dt ns
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Future KM3NeT

• A km3 (or larger) is the desirable volume for a
  neutrino telescope.
• The KM3NeT Design Study has been approved by the
  European Union.
• The three Mediterranean experiments collaborate
  in this study ANTARESNEMONESTOR.
• Complementary to IceCube at the South Pole in
  order to cover the whole sky.
• Technical Design Report early 2009.

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Conclusions

• The deployment of Line 1 and the on-going data
  taking is a great success.
• Currently ANTARES is operating with the MILOM and
  Line 1 simultaneously.
• 2nd line deployment this summer, the whole
  detector will by finished by end 2007.
• Atmospheric muons have been reconstructed.
  Presently working on angular distributions.
• ANTARES will cover the South sky with an expected
  angular accuracy of 0.3º thanks to the optical
  properties of water and the good detector
  performances (electronics, calibration, etc).