the antares neutrino telescope mieke bouwhuis 27/03/2006
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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