the antares neutrino telescope

The ANTARES Neutrino Telescope

Mieke Bouwhuis27/03/2006

Broadband light source

1’ 1’1’ 1’

radio 10-8 eV optical 10 eV x rays 104 eV gamma rays 1012 eV

The pulsar in the Crab nebula

The observed radiation

e-

e-

Synchrotron radiation Inverse Compton scattering

But: for some sources no synchrotron radiation is seen…

All particle cosmic ray spectrum

energy (eV)

rela

tive

part

icle

flu

x (lo

garit

hmic

uni

ts)

No point sources found yet

e, , p and from cosmic accelerators

e

e e

e

0,p X accp

Neutrinos from high-energy sources

Neutral point back Weak interaction no absorption

Active GalacticNucleus (AGN)

SupernovaRemnant (SNR)

Gamma-rayBurst (GRB)

Pulsar Microquasar

Indirect neutrino detection

Neutrino interaction (e, , ):

med

ian

scat

terin

g an

gle

(deg

rees

)

neutrino energy (GeV)

Scattering angle

s

1.5θ

TeVE

Neutrino cross section

neutrino energy (GeV)

cros

s se

ctio

n (c

m2 ) 1

AN

Mean free path:

~108 m at 1 TeV

Very large volume needed

The ANTARES neutrino telescope

Mediterranean Sea, near Toulon

Detection volume and medium

sea + earth = large volumeInstrumented volume = 0.02 km3

Effective volume = 0.2 km3 (at 10 TeV)

= 1 km3 (at 10 PeV)

water for production of Cherenkov light

water is transparent

depth of 2.5 km for shielding against atmospheric background

c(tj - t0) = lj + dj tan(c)

= 0.2°x = 20 cmt = 1 ns

Detection principle

water properties

Signals in the detector

Signals in the detector

crosses the detector in 2 s

100 kHz

Different types of background

atmosphere

sea

Earth

proton

proton

cosmic

atmospheric

atmospheric

random background 100,000 hits/s per phototube

atmospheric ~300/s

atmospheric ~10-3/s

ANTARES data processing system

filter

PC physics data

all raw data10 Gb/s

1 Mb/sanalysis

shore station

• finds all correlated data• real time• data reduction by factor 104

• high efficiency (50%)• high purity (90%)• low threshold: E > 200 GeV

finds cosmic neutrinos

Angular resolution

February 14, 2006

March 2, 2006

Line 1: data taking

LED beaconcalibration

Physicsdata taking

LED beacon for time calibration

MILOM

Line 1

~70 m

Event Display – LED beacon

Muon trigger ratera

te (

Hz)

number of correlated hits

real data

Monte Carlo

Physics event found by filter:

space-time correlated hits

“snapshot” hit

4 s

Event Display

Physics event found by filter:

space-time correlated hits

“snapshot” hit

4 s

: hits used by the fit

Physics event 17267 in run 21241

Event Display

zenith angle = 179°

Physics event 17267 in run 21241

Event Display

zenith angle = 146°

Event Display

zenith angle = 80°

Upgoing!

Zenith angle distribution

1394 events after 14 hours of data taking

Gamma-ray bursts (GRB)

short and intense flashes of MeV gamma rays

happen unexpectedly, and take place at random locations in the sky

detected by satellites

most information from the observation of the ‘afterglow’

mechanism:

GRB warning systems

Detection of neutrinos from GRBs

filter

PC

• All-data-to-shore concept

• Data processing farm

• Software filters

Specific ANTARES featuresGRB warning systems GRB features

GRB duration (s)

Combine into the “GRB method”

Data taking after a GRB alert

Delays and buffering

Gain in sensitivity for GRBs

neutrino energy (GeV)

ratio

of

effe

ctiv

e vo

lum

es

standard

GRB method

Conclusions

Composition of jets → e versus p

Origin of UHE cosmic rays

Line 1 operational, 12 lines end of 2007

Measured time resolution of ~1 ns

Expected angular resolution 0.2°

GRB method increases the sensitivity