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13th Lomonosov Conference on Elementary Particle Physics Moscow, August 23 – 29, 2007. Acoustic Particle Detection and the ANTARES Neutrino Telescope Topics: Astroparticle Physics with Neutrinos ANTARES Neutrino Telescope Acoustic Detection of Neutrinos. - PowerPoint PPT Presentation
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Kay GrafUniversity of Erlangen
for the ANTARES Collaboration
13th Lomonosov Conference onElementary Particle PhysicsMoscow, August 23 – 29, 2007
Acoustic Particle Detection and the ANTARES Neutrino Telescope
Topics:- Astroparticle Physics with Neutrinos
- ANTARES Neutrino Telescope- Acoustic Detection of Neutrinos
August 23 – 29, 200713th Lomonosov Conference
Kay Graf University of Erlangen2
Astroparticle Physics with (U)HE Neutrinos
Low-energy limit:• detector
sensitivity• background
High-energy limit:• neutrino flux
decreases like E–n (n ≈ 2)
• large detectionvolume needed
optical Cherenkov telescopes:
Baikal, IceCube, ANTARES, …
new techniques: radio, acoustics, … (many experiments)
…
August 23 – 29, 200713th Lomonosov Conference
Kay Graf University of Erlangen3
Two (U)HE Detection Methods
optical optical ChCherenkoverenkovconecone
photosensor
array
acoustic acoustic pressure pressure waveswaves
hydrophone array
cascadecascade
Optical Cherenkov detector• 3D array of photosensors
• attenuation lengths of order 50m to 100m (blue light)
• medium: water, ice
Acoustic detector• 3D array of hydrophones
• very long attenuation lengths
(of order 1km)• medium: water, ice and salt
established technology
established technology
feasibility studies
feasibility studies
August 23 – 29, 200713th Lomonosov Conference
Kay Graf University of Erlangen4
14.5m
100 m
25 storeys,350 m
Junction Box
~70 m
The ANTARES Neutrino Telescope
• string-based detector (Lines)
• ¼ 0.1 km2 geometric area
• downward-lookingphotomultipliers (PMs),axis at 45O to vertical
• 2400 m water depth• 25 km off shore
ANTARESsite
F I
E
August 23 – 29, 200713th Lomonosov Conference
Kay Graf University of Erlangen5
Current Status and Plans
Full detector: 12 Lines with 900 PMs
1 Instrumentation Line (IL) for environment
monitoring
Running: 5 Lines (375 PMs)
+Installed:
4 Lines + IL,to be connected this
year
Completion:Early in 2008Early in 2008
Acoustic setup:
6 storeys(36 sensors)
August 23 – 29, 200713th Lomonosov Conference
Kay Graf University of Erlangen6
Muon Event in the Optical Detector
hit pattern depending on zenith angle anddistance from string
hit time (ns)
hit
alt
itu
de z
(m
) middle of the
detector
first triggered hit
Line 1
August 23 – 29, 200713th Lomonosov Conference
Kay Graf University of Erlangen7
hit time hit time hit time
hit time
hit
alt
itu
de
hit
alt
itu
de
hit
alt
itu
de
hit time
hit
alt
itu
de
hit
alt
itu
de
Selected Events: Muon Bundle
August 23 – 29, 200713th Lomonosov Conference
Kay Graf University of Erlangen8
Line 1 Line 2
Line 4
Line 3
Line 5
hit time hit time hit time
hit time
hit
alt
itu
de
hit
alt
itu
de
hit
alt
itu
de
hit time
hit
alt
itu
de
hit
alt
itu
de
Selected Events: Neutrino Candidate
triggered hits on three Lines
zenith angle:
θ = 35°-700 400
1500ns
August 23 – 29, 200713th Lomonosov Conference
Kay Graf University of Erlangen9
Nadir Angle Distribution
without alignmentmore information:
talk of V. Flaminio on Monday
from above
from below *
August 23 – 29, 200713th Lomonosov Conference
Kay Graf University of Erlangen10
The Acoustic Setup
~240m
~12
0m
~1m
acousticacousticstorey storey (AS)(AS)
6 storeys with 6 sensors each atdifferent length scales (1 m – 350 m)
~15
m
~350m
acousticacousticstorey storey (AS)(AS)
major questions:
• acoustic noise at the ANTARES site
• rate of neutrino-like background pressure pulses
August 23 – 29, 200713th Lomonosov Conference
Kay Graf University of Erlangen11
~~10m10m hadroniccascade
¼
1kmS. Bevan et al.,
arXiv:0704.1025
energy deposition in (hadronic) cascade ) bipolar pressure pulse in disc shape
The Acoustic Signal of UHE Neutrinos
August 23 – 29, 200713th Lomonosov Conference
Kay Graf University of Erlangen12
background noise at low wind speed:¼ 3 mPa (rms, 1 – 100 kHz)
, P (1EeV@1000m)
Noise in the Deep Sea
N.G. Lehtinen et al., Astropart. Phys., 17(2002), p. 279
August 23 – 29, 200713th Lomonosov Conference
Kay Graf University of Erlangen13
DAQ Characteristics
preliminary
inherent noise comparable to lowest sea state
• typical sensitivity: ¼ 0.2 V/Pa
• variable post amplification: gain factor ¼ 1 – 500
• digitization:in the sea at 16bit with 125 – 500 kSamples/sec
1knot1knot
3knots3knots
10knots10knots
inherent
noise
August 23 – 29, 200713th Lomonosov Conference
Kay Graf University of Erlangen14
Simulations of an Acoustic Detector
T. Karg, PhD Thesis, astro-ph/0608312 (2006)
strongly dependent on detection threshold of sensors
) design and test efficient signal processing algorithms
withoutquality cuts
August 23 – 29, 200713th Lomonosov Conference
Kay Graf University of Erlangen15
Simulations of an Acoustic Detector
T. Karg, PhD Thesis, astro-ph/0608312 (2006)
GZK event rate: 0.01 – 0.1 per km3 yr) detector size > 100 km3 (not with optical
detector)
withoutquality cuts
August 23 – 29, 200713th Lomonosov Conference
Kay Graf University of Erlangen16
Summary and Outlook
• Astroparticle physics with neutrinos is important and complementary to the study of other cosmic
particles
• The ANTARES neutrino telescope is approaching its completion
• 5 lines are working well and delivering a lot of physics data
) first neutrino candidates
• Analysis of the data is in progress, understanding of the detector has to be improved
• Feasibility test for a future acoustic detector will start this year with an dedicated array of sensors
