NESTOR

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NESTOR

• Neutrino
• Extended
• Submarine
• Telescope with
• Oceanographic
• Research
• Collaboration of 18 Institutes in 5 countries
• ? 80 people

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NESTOR
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• Site characteristics
• a broad plateau 8x9 km2 in area, 7.5 nautical
  miles from shore
• depth 4000m
• transmission length 55 10m at ?460 nm
• underwater currents lt10 cm/sec
  measured over the last 10 years
• optical background 50 kHz/OM due to K40 decay,
  bioluminescence activity
  (1 of the experiment live time)
• sedimentology tests flat clay surface on sea
  floor good
  anchoring ground.
• No bombs!
• No submarines!

NIM. A 349 pp 242-6
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NESTOR Workshops
NESTOR INSTITUTE
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Detector Preparation Bay Station Tests
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Design Considerations

• Refrain from using Bathyscaphs , ROVs
• ? Reduce cost safety risks
• No highly specialized surface vessels (?)
• ? Deployment platform Delta-Berenike is being
  build
• All connections to be made in the air
• Minimize number of connectors
• As passive a system as possible
• ? No trigger bias, get data and make selections
  later on shore
• Modularity with build-in Redundancy
• Retrievable and expandable

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Detector Structure - Star
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Titanium Star Structure
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At center of each floor, a Ti sphere houses the
electronics
NESTOR TOWER
32 m diameter 30 m between floors
144 PMTs facing up down
20 000 m2 Effective Area for Egt10TeV
An Optical Module (i.e. a15 PMT with HV power
supply within protective glass housing).
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The 2003-Detector
Single p.e. conditions
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Ti-Sphere Electronics Designed built by
Lawrence Berkley National Laboratory

• Floor Board
• PMT pulse sensing
• Majority logic event triggering
• Single coincidence rat scaling
• Waveform capture digitization
• Data formatting transmission
• In-situ reprogrammable

• House Keeping Board
• PMT HV control
• Calibration Beacon control
• Power supply monitor
• Environmental monitors

PMT signal digitization
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ReadOut Electronics DAQ Chain

• Shore Board
• Upload configuration to floor
• Broadcast clock
• Receive data from floor
• Send data to tape monitors

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The Real GameJanuary 2002
ElectroOptical cable to shore (18 fibers 1
conductor) Cable repaired in January 2002
by the cableship TENEO (TyCom) Successful
deployment of the anchor unit with environmental
sensors to 4000m
A NESTOR floor deployment was postponed
due to the bad weather conditions
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Our January 2002 deployment article, is published
in July issue of Sea Technology, plus, our
pyramid-Bottom Station (LAERTIS) makes the cover
picture of this journal.  
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2003
Successful deployment of one NESTOR star with 12
Optical Modules to 4000m using the cableship
RAYMOND CROZE (FranceTelecom) 29th of March
The first deep sea muon data transmitted
to shore
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NESTOR Star Deployment (March 2003)
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Data from a depth of 4000 m PMT Pulse Height
Distribution
K40 Background A stable calibration source
Calibration Lab.
single p.e. LED Run
single p.e. pulse height distribution two p.e.s
pulse height distribution dark current pulse
height distribution sum of the above
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Data from a depth of 4000 m Bioluminescence
Up facing PMTs
Down facing PMTs
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Data from a depth of 4000 m Bioluminescence
Contribution to the Total Trigger Rates
Bioluminescence Occurs for the 1.1 0.1 of
the Active Experimental Time
Total Trigger Rates Bioluminescence Contribution
to the Total Trigger Rates Experimental Trigger
Rates from Periods Without Bioluminescence
In good agreement with large number of free
drop measurements taken over past 6 years
season independent
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Event 1785 Run 81 BFile 3
17 p.e.s
5 p.e.s
1 p.e. 120mV
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Run 63_37 Event 396
18 p.e.s
4 p.e.s
12 p.e.s
1 p.e. 120mV
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Run 63_37 Event 396
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Zenith Angular Distribution

• PMT pulse selection
• Track fit
• ?2 probability gt 0.1
• track selection according to the
  charge-likelihood
• impact parameter gt 6 meters
• more than 4.5 (number of hits)p.e.s per track

Fitted with cos(?)a
a4.650.9
M.C. Prediction (atmospheric muons) Data Points
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Conclusions

• DEEPER IS BETTER
• NOT ONLY BECAUSE OF THE REDUCTION
• OF THE NUMBER OF DOWNCOMING MUONS
• GAIN ALMOST TWO ORDERS OF MAGNITUDE IN
• SOURCE FLUX SENSITIVITY WHEN YOU GO
• FROM 1000m to 4000m
• IT IS MUCH CLEANER
• LESS BIOLUMINESCENCE
• OCCURRENCE 1 FOR NESTOR
• OPERATING A NEUTRINO TELESCOPE AT 4000m
• IS REALISTIC

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The next phases of NESTOR

• NuBE NESTOR
• Neutrino Burst Experiment with NESTOR
• Proposal to Measure High Energy Neutrinos in
  Coincidence with Gamma Ray Bursts
• Preparations in progress

• KM3NeT
• A km3-scale neutrino telescope
• in the Mediterranean Sea
• The three year design study is in progress

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The KM3NeT Project Design Study for a Deep Sea
Facility in the Mediterranean forNeutrino
Astronomy and Environmental Sciences
KM3NeT collaboration of 37 European Institutes,
including members of the ANTARES, NEMO and NESTOR
experiments, which have joined together to design
and construct a cubic kilometer-scale underwater
neutrino telescope and platform for deep-sea
science.
Institutes participating in the Design
Study Cyprus Univ. CyprusFrance CEA/Saclay,
CNRS/IN2P3 Marseille, CNRS/IN2P3 Strasbourg,
Univ. Haute Alsace Germany Univ. Erlangen
Greece Hellenic Open Univ., NCSR Demokritos,
NOA/Nestor Inst.,Univ. Athens, Univ. Crete, Univ.
PatrasItaly INFN (Bari, Bologna, Catania, LNS
Catania, LNF Frascati, Genova, Messina, Pisa,
Roma-1) Netherlands NIKHEF (Univ. Amsterdam,
Free Univ., Univ. Utrecht, Univ. Nijmegen)
Spain IFIC (CSIC, Univ. Valencia), U.P.
ValenciaUnited Kingdom Univ. Leeds, Univ.
Sheffield, Univ. Liverpool
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• What is our aim ? a deep-sea km3-scale
  observatory for high energy neutrino astronomy
  and associated platform for deep-sea science
• Why we need an FP6 Design Study ? to enable the
  European neutrino astronomy community to prepare
  for the timely and cost-effective construction of
  the next-generation neutrino telescope
• Why we need it now ? ... both in view of the
  size of the enterprise and of a timely
  competition with IceCube, the Committee finds it
  urgent that a single coherent collaboration be
  formed, ...Recommendation from ApPEC peer
  review meeting, Amsterdam, 3-4 July 2003

• The Mediterranean Sea offers optimal conditions
• water quality, depth, temperature, ...
• existing infrastructure
• current expertise for sea water n telescopes
  concentrated in European countries
• a perfect stage for a large Europe-led science
  project

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Physics Perspectives of KM3NeT

• The observation of cosmic neutrinos above 100
  GeV is of great scientific importance. ...
• ... a km3-scale detector in the Northern
  hemisphere should be built to complement the
  IceCube detectorbeing constructed at the South
  Pole.
• The detectors should be of km3-scale, the
  construction of which is considered technically
  feasible.

Astronomy via high-energy neutrino
observation Production mechanisms of high-energy
neutrinos in the universe (acceleration
mechanisms, top-down scenarios, . . .
) Investigation of the nature of astrophysical
objects Origin of cosmic rays Indirect search for
dark matter Associated science
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Birds eye view of a proposed Cubic
Kilometer size telescope made of 13 towers
Concentric , variable density array to cover
energy range GeV to PeV
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while designing KM3NeT
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NuBE - NESTOR
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NuBE - NESTOR
NESTOR tower with 4 autonomous strings,
omnidirectional, effctive area 2km2, to detect
neutrinos which produce highly radiative leptons
muons shower (catastrophic bremsstrahlung) in
km-range and electrons or neutral-current events
(cascades) very bright showers in 0.1km-range
NESTOR 4-floor tower
Photon detector nodes16 PMT each
Expect 40-200 neutrino events/yr of 100TeV In
coincidence with GRBs detected by satellites
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Back-up slides
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Deployment Platform Under Construction
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The LED Calibration System
Frequency Duration Light amplitude

• Gain monitoring
• Timing
• Free running Calibration Trigger
• Adjustable Trigger frequency
• Adjustable LEDs light output

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Data from a depth of 4000 m Trigger
Studies Preliminary
Thresholds at 30mV (1/4 P.E.)
Data Collected with 4fold Majority Trigger
Thresholds at 120mV (1 P.E.)