High Energy Neutrino Astronomy

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High Energy Neutrino Astronomy
E. Migneco
Istituto Nazionale di Fisica Nucleare Laboratori
Nazionali del Sud
Dipartimento di Fisica e Astronomia Università di
Catania
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The High energy Universe
Cosmic Rays with energies up to 3 ? 1019 eV have
been observed Low energy region (up to 1015 eV)
probably of galactic origin The hardening of the
spectrum in the high energy tail (E gt 1019 eV)
may be an indication of an extragalactic
component Still some open problems Particle
acceleration mechanisms Identification of the
sources Solution of the UHECR puzzle
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A high energy source example the SNR RX
J1713-3946
RX J1713-3946
Good angular resolution allows for extended
source morphology studies
Power low spectrum observed up to 30 TeV Spectral
index 2.1 - 2.2 Implies acceleration of
primaries up to 1000 TeV Spectrum hardly
explainable with IC mechanisms call for proton
acceleration
F. Aharonian, TAUP 2005
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Probes for high energy astronomy
The Universe is not transparent for HE photons
and protons
? ?CMB ? e e- p ?CMB ? ? ? n ? ? ?
??
Protons with E lt 1019 eV are deflected by
magnetic fields Need neutrinos to observe the
distant Universe at high energy
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Neutrino production mechanism
Production mechanism
Man made accelerators
Cosmic accelerators

• Proton acceleration
• Fermi mechanism
• proton spectrum dNp/dE E-2

• Neutrino production
• Interaction of protons
• p ? p (SNR,X-Ray Binaries)
• p ? ? (AGN, GRB, microQSO)
• p e µ decay

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Motivations for neutrino astronomy

• Neutrinos can travel without being deflected or
  absorbed
• They point back to their sources
• They can allow to see the innermost regions of
  the cosmic sources that are unaccessible to
  electromagnetic radiatio
• They can allow the observation of the distant
  Universe
• Neutrinos are produced in hadronic interactions
• Neutrino detection can be the smoking gun to
  disentagle between adronic and leptonic
  acceleration processes
• They can disentangle betwwen astrophysical models
  in the description of the Black Hole in the
  Galactic Centre
• Can be produced in the decay or annhilation of
  dark matter

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The scale size of a high energy neutrino telescope
One can derive a reference neutrino flux
normalizing to the energy flux of extra galactic
High Energy Cosmic Rays The expected event rates
of this Waxmann-Bahcall flux are approximately
given by
The observation of TeV neutrinos needs km2 scale
detectors
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Principles of neutrino astronomy detector concept
atmospheric muon
5000 PMT
Cherenkov light
neutrino
Detection of Cherenkov light in transparent
natural media (water or ice)
muon
depth gt3000m
neutrino
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The international context
BAIKAL, AMANDA small scale detectors presently
in data taking NESTOR, ANTARES, NEMO RD under
construction ICECUBE under construction
(expected 2010) KM3NeT Mediterranean EU Design
Study (2006-2008)
BAIKAL
Pylos
Mediterranean km3
La Seyne
Capo Passero
AMANDA ICECUBE
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IceCube
Technology for under-ice detectors is
reliable Next step is the construction of the km3
detector IceCube
IceTop air shower array 80 pairs of ice Cherenkov
tanks
80 strings (60 PMT each) 4800 10 PMT (only
downward looking) 125 m inter string distance 17
m spacing along a string Instrumented volume 1
km3 (1 Gton)
IceCube strings IceTop tanks 4 (1) 8 Jan
2005 16 (9) 32 Jan 2006 32 64 Jan
2007 50 100 Jan 2008 68 136 Jan 2009 80 160
Jan 2010
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The IceCube detector at the South Pole
IceCube hot water drilling system
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The sky view from North and South Hemispheres
South Pole
Mediterranean
Mkn 421
Mkn 501
Mkn 501
Not seen
CRAB
CRAB
VELA
SS433
SS433
Not seen
GX339-4
Galactic Center
Need two telescopes to cover the whole sky
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The NEMO Collaboration
INFN Bari, Bologna, Catania, Genova, LNF, LNS,
Napoli, Pisa, Roma Università Bari, Bologna,
Catania, Genova, Napoli, Pisa, Roma La
Sapienza CNR Istituto di Oceanografia Fisica, La
Spezia Istituto di Biologia del Mare,
Venezia Istituto Sperimentale Talassografico,
Messina Istituto Nazionale di Geofisica e
Vulcanologia (INGV) Istituto Nazionale di
Oceanografia e Geofisica Sperimentale
(OGS) Istituto Superiore delle Comunicazioni e
delle Tecnologie dellInformazione (ISCTI)
More than 80 researchers from INFN and other
italian institutes
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The Capo Passero site
The site has been proposed in january 2003 to
ApPEC as a candidate for the km3 intallation

• Depths of more than 3500 m are reached at about
  100 km distance from the shore
• Water optical properties are the best observed in
  the studied sites (La 70 m _at_ ? 440 nm)
• Optical backgroung from bioluminescence is
  extremely low
• Stable water characteristics
• Deep sea water currents are low and stable (3
  cm/s avg., 10 cm/s peak)
• Wide abyssal plain, far from the shelf break,
  allows for possible reconfigurations of the
  detector layout

contributo I. Amore
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Feasibility study for the km3 detector
Detector architecture issues Reduce the number of
structures to reduce the number of underwater
connections and allow operation with a
ROV Detector modularity
Towers with non homogeneous distribution of
sensors
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Tower detector performance
Sensitivity Sensitivity to point-like sources
(Ev-2 spectrum)
Reconfigurability Effective areas with different
element spacing
IceCube simulations from Ahrens et al. Astrop.
Phys. 20 (2004) 507
tower floor spacing spacing Black line 140 m 40
m Red square 300 m 60 m Black points 300 m 40 m
NEMO 81 towers 140m spaced - 5832 PMTs IceCube 80
strings 125m spaced - 4800 PMTs
NEMO search bin 0.3 IceCube search bin 1
contributi R. Coniglione, C. Distefano
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The LNS Underwater Test Site
Underwater infrastructure realized by the
Laboratori Nazionali del Sud to test detector
prototypes
SN-1
Shore station
North branch 5.220 m
Double armed cable 2.330 m
BU
NEMO Phase-1
Single armed cable 20.595 m
South branch 5.000 m
contributo F. Speziale
January 2005 Installation of SN-1 (INGV) and
OnDE (INFN) December 2006 Installation of NEMO
phase 1
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NEMO Phase-1 deployment December 2006
Mini-Tower unfurled
NEMO mini-tower (4 floors, 16 OM)
contributi R. Papaleo, M. Musumeci
Junction Box
TSS Frame
300 m
Mini-Tower compacted
15 m
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The Junction Box

• Data transmission electronics
• Power distribution and control system
• Optical fibre splitters
• Innovative design to decouplethe corrosion and
  pressureresistance problems

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Mini Tower components
The tower assembled at the NEMO Test Site shore
laboratory
Floor 4
Floor 3
Tensioning ropes
Floor 2
Break-out
Floor control module
Floor 1
Optical modules
Backbone cable (electro-optical) Nexans-D0330
Tensioning ropes
Backbone e.o. cable
Mechanical stresses are applied only to the
tensioning ropes
Tower Base Module
e.o. Jumper cable Tower base - JB
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The mini Tower
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The mini Tower
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The mini Tower
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First muon tracks
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The NEMO Phase-2 project
A deep sea station on the Capo Passero site

• OBJECTIVES
• Realization of an underwater infrastructure at
  3500 m on the CP site
• Test of the detector structure installation
  procedures at 3500 m
• Installation of a 16 storey tower
• Long term monitoring of the site
• INFRASTRUCTURE UNDER CONSTRUCTION
• Shore station in Portopalo di Capo Passero
• 100 km electro optical cable
• Underwater infrastructures
• STATUS
• Electro-optical cable (gt50 kW, 20 fibres) ordered
• A building (1000 m2) located inside the harbour
  area of Portopalo has been acquired. Procedures
  for its renovation started
• Project completion planned in 2007

contributi A. DAmico, D. Lo Presti
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The KM3NeT European Design Study
The experience and know-how of the three european
collaborations is merging in the KM3-NET activity

• Collaboration of 8 Countries, 34 Institutions
• Aim to design a deep-sea km3-scale observatory
  for high energy neutrino astronomy and an
  associated platform for deep-sea science
• Funded for 3 years (2006-2009)

Physics Analysisand Simulations
System and Product Engineering
Information Technology
Shore and deep-sea structure
Sea surface infrastructure
WORK PACKAGES
Risk Assessment Quality Assurance
Resource Exploration
Associated Science
A Technical Design Report (including
recommendation on site choice) for a Cubic
kilometre Detector in the Mediterranean
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Conclusions
Neutrino astronomy will open a new observational
window on the Universe First generation
experiments have proven the feasibility of the
Cherenkov detection technique The realization of
an underice detector at the South Pole has
already started The technologies for the
realization of a km3 neutrino telescope are now
mature An EU Design Study (KM3NeT) towards the
km3 detector is under way