first data of antares neutrino telescope francisco salesa greus ific (csic–universitat de...

First data of ANTARES First data of ANTARES neutrino telescopeneutrino telescope

Francisco Salesa GreusFrancisco Salesa Greus

IFIC (CSIC–Universitat de València, Spain)IFIC (CSIC–Universitat de València, Spain)

On behalf of the ANTARES collaborationOn behalf of the ANTARES collaboration

The 3rd International Workshop onThe 3rd International Workshop onTHE HIGHEST ENERGY COSMIC RAYS AND THEIR SOURCESTHE HIGHEST ENERGY COSMIC RAYS AND THEIR SOURCES

May 16-18 2006, INR-Moscow, RussiaMay 16-18 2006, INR-Moscow, Russia

Francisco SalesaFrancisco Salesa 22

Cosmic Ray spectrumCosmic Ray spectrum

SNR origin Galactic origin (several theories)

GZK cut-off: end of the cosmic ray spectrum??

AGN, top-down

models??

Extra-galactic origin

1 particle per m2 per second. 1 particle per

m2 per year.1 particle per km2 per year.

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


e-Low energy emission (X-ray) :Synchrotron emission of e- in jet

High energy emission (-ray):

- inverse-compton (electronic)?

e-

±

±

ee±

If hadronic origin high energy neutrinos

p

0 decay (hadronic) ?

Neutrino connectionNeutrino connection

High energy Cosmic Ray flux can constrain neutrino fluxes (Waxman-Bachall limit).


Physic topicsPhysic topics

Galactic Centre

SNR

Binary systems

Micro-quasars

AGN

GRB

Neutrino Astrophysics

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.

Extragalactic sourcesGalactic sources


Detection principleDetection principle HE neutrino from extraterrestrial sources interacts in a CC

reaction with the surrounding media.

A muon is produced which induces Cherenkov light emission.

Light Cherenkov is recorded by an array of PMTs.

Cosmic accelerator

X

reach the detector, not deflected

absorbed by matter and EBL

p deflected by magnetic fields, GZK effect

Earth

CMB

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

1.2 TeV muon traversing the detector


Physical backgroundPhysical background Two muon backgrounds:

-1 0 1 cos

10-8

10-11

10-14

10-17

(cm-2s-1sr-1)

p

p

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

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

The atmospheric flux is 6 orders of magnitude higher than the flux induced by atm.

ee

Kp

...)(

ee

Kn

...)(


ANTARES collaborationANTARES collaboration

21 Institutions from 6 European countries

Submarine cable

ANTARES detector located 40 km off Toulon coast (42º50’N 6º10’E) at 2500 metres depth.

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


The ANTARES detectorThe ANTARES detector

Horizontal layout

60-75 m

100 m

350 m

12 lines3x25 PMT/line

Junction box

Buoy

Interlink cable

Storey

40 km electro-optical cable to shore

12 lines

25 storey/line

3 PMT/storey

900 PMTs in total

Anchor(BSS)

Submersible


The ANTARES devicesThe ANTARES devices

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 Hydrophone (Rx) for positioning.

The Storey

The Local Control Module houses, in a titanium frame, the electronic cards devised for the readout of the three OMs .

The LED Beacon for time calibration purposes.


The ANTARES devicesThe 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.Junction box

BSS


Time calibrationTime calibration An internal LED monitors the

transit time of the PMT. The Optical beacons are external

light sources for timing calibration60 m

300

m

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.

60 m

300

m

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


PositioningPositioning

Autonomous Pyramid

BSS

Electro-optical cable to shore

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.

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.

Roll

The Positioning System provides

10 cm accuracy for each OM.

Five Rx (receiving hydrophones) distributed in each line.

One tiltmeter-compass card per storey.

Pitch


Detector performanceDetector performance Effective area Angular resolution

Earth opacity effect.

Below 10 TeV is dominated by the kinematic angle .

Over 10 TeV dominated by reconstruction (calibration, electronics, etc.)

kinematics

reconstruction

rec, true

rec, true

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.


Point-like source candidatesPoint-like source candidates

ANTARES will observe 3π sr (galactic centre visible 67% of the time). Complementary to AMANDA/IceCube at the South Pole (0.6π sr overlap). HESS observations of RX J1713-3946 SNR spectrum show a presumably hadronic

scenario, thus neutrino emission is expected (Nature 432 (2004) 75).

TeV sources candidates.

Galactic centre

SNR RX

J1713-3946

Vela pulsar


Source detectionSource 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.


Collaboration milestones & Collaboration milestones & scheduleschedule

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.

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

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).

1996-1999: R&D and site evaluation period.

FINAL DESIGN

PROTOTYPES

R&D


Site evaluation resultsSite evaluation results

blue (470 nm) UV (370 nm)

abs 60 ± 8 m 26 ± 2 m

sct(eff) 265 ± 30 m 120 ± 4 m

Water properties.

Biofouling. Optical background.

measured with pulsed LEDs

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.

cos1

scateffscat


MILOM lineMILOM line Instrumentation line + OMs:

MILOM sketch

4 OMs. 2 LED Beacons. 1 Laser beacon.

1Rx hydrophone. 1RxTx transponder.

Successfully test of DAQ and electronics.

MILOM is still operating.

Sound velocimeter. Seismometer. Acoustic Doppler Current

Profiler. Conductivity Temperature probe.

3 Storeys.


Results from MILOMResults from MILOM Site properties:

Example of data taking rate

Baseline

Bursts

Baseline evolution with time

Water current velocity evolution with time

Heading of the three MILOM storeys

Currents < 20 cm/s

~5 cm/s on average

Correlation with currents has been noticed

~120 kHz

Seasonal variations

~60 kHz

summerautumn


Results from MILOMResults from MILOM Spatial Calibration:

WF signal example.

Charge Calibration:

Distance from autonomous line (RxTx) to MILOM RxTx, evolution with time.

175 m

96 m

Evolution with time of the normalized charge.


Results from MILOMResults from MILOM

Internal LED t evolution with time

MILOM LEDbeacon

Storey

Time Calibration:

OM signal – beacon PMT time difference for each OM.

The rate measured of these coincidences is ~13 Hz which is in agreement with the estimations.

40K coincidences between OMs.


Line 1 deploymentLine 1 deployment

Line anchor

Buoy

OM

LED beacon25 storeys + 1 BSS

RxTx


Line 1 deploymentLine 1 deployment

February 2006 March 2006


First muons reconstructed First muons reconstructed with Line 1with Line 1

Triggered hits Hits used in fit Snapshot hits

t [ns]

z [m

]

+

Result of FitAntares preliminary

21240 / 12505 = 101o

P(2,ndf) = 0.88

21240 / 12527 = 172o

P(2,ndf) = 0.94

Antares preliminary

21240 / 12845 = 72o

P(2,ndf) = 0.37

Antares preliminary

Run / Event Zenith angle Fit probability


Atmospheric Muon BundlesAtmospheric Muon BundlesMontecarlo Reconstruction

t [ns]Nu

mb

er

of

eve

nts

[a

rbitr

ary

un

its]

Time residuals

= 7.8 ns

Antares preliminary

Num

ber

of e

vent

s [a

rbitr

ary

units

]

Antares preliminary

P(2,ndf)

t [ns]Nu

mb

er

of

eve

nts

[a

rbitr

ary

un

its]

Num

ber

of e

vent

s [a

rbitr

ary

units

]

P(2,ndf)

Antares preliminary

Antares preliminary

Time residuals

= 7.8 ns


Line 1 calibrationLine 1 calibration

MILOM LED Optical Beacon

Line 1

~70 m

~150 m

= 0.7 ns

= 2.6 ns

t [ns]

Nu

mb

er

of e

vent

s [a

rbitr

ary

un

its]


Future: KM3NeTFuture: 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: ANTARES+NEMO+NESTOR.

Complementary to IceCube at the South Pole in order to cover the whole sky.

Technical Design Report early 2009.


ConclusionsConclusions

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).

first data of antares neutrino telescope francisco salesa greus ific (csic–universitat de...

Documents

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antares detector60

antares devicesa

neutrino oscillations

detector depth

cosmic acceleratornm

basis of energy spectrum

wide energy spectrum