the km3net project
DESCRIPTION
The KM3NeT project. Introduction & Main objectives The KM3NeT Technical Design Report Telescope physics performance New developments Summary. Motivation for the high energy neutrino detection. Neutrino will provide unique pieces of information on High Energy Universe Physics case - PowerPoint PPT PresentationTRANSCRIPT
P. Sapienza, NOW 2010
The KM3NeT project
Introduction & Main objectives The KM3NeT Technical Design Report Telescope physics performance New developments Summary
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P. Sapienza, NOW 2010
Motivation for the high energy neutrino detection
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Neutrino will provide unique pieces of information on High Energy Universe
Physics caseAstrophysical high energy neutrino sources (SNR, microquasars, AGN, GRB)Origin of cosmic raysUnknown neutrino sources Indirect search of Dark Matter
P. Sapienza, NOW 2010
Detection principle – TeV-PeV => Optical Cherenkov
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• Upward-going neutrinos interact in rock or ice or sea/lake water.
• Emerging charged particles (in particular muons) produce Cherenkov light in water/ice
• Detection by array of photomultipliers
• Muon direction reconstructed from photon arrival times and PMT positions
Estimates indicate that a detector size of the order of km3 is needed for n astronomy
P. Sapienza, NOW 2010
High energy neutrino telescope world map
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AMANDAIceCube
ANTARES, NEMO, NESTOR
KM3NeT
BaikalPylos
La Seyne
Capo Passero
P. Sapienza, NOW 2010
KM3NeT: towards a km3-scale n telescope in the Mediterranean Sea
KM3NeT consortium consists of 40 European institutes including those in Antares, Nemo and Nestor
KM3NeT Design Study defined telescope design and outlined main technological options
Approved under the 6° FP (funded by EU for the period 2006-2009) Conceptual Design Report published in 2008 http://www.km3net.org/public.php Technical Design Report (TDR) outlines technologies for the construction,
deployment and maintenance of a deep sea neutrino telescope http://www.km3net.org/public.php (TDR contents frozen in November 2009)
KM3NeT Preparatory Phase define legal, governance and funding aspects. Production planes for the detector elements, infrastructure features and prototype validation will be also defined Approved under the 7° FP (funded by EU for the period 2008-2012)
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P. Sapienza, NOW 2010
KM3NeT main objectives
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Energy range and main physics goals Investigate neutrino “point sources” optimisation in the energy
regime 1-100 TeV with a coverage of most of the sky including the Galactic Centre
Implementation requirements Construction time ≤5 years Operation over at least 10 years without “major maintenance”
Cabled platform for deep-sea research (marine sciences)
P. Sapienza, NOW 2010
Sky view of a Mediterranean Sea telescope
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>75%>25%
KM3NeT complements the IceCube field of view KM3NeT observes a large part of the sky (~3.5p)
Sensitivity for up-going
neutrinos considered
From Mediterranean 24h per day
visibility up to
about d=-50°
P. Sapienza, NOW 2010
KM3NeT: an artistic view
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Primary Junction box Secondary Junction boxes
Detection Units
Electro-optical cable
P. Sapienza, NOW 2010
Technical Challenges and Telescope Design
Technical designObjective: Build 3D-array of photodetectors andconnect them to shore (data, power, slow control)
Optical modules Data acquisition, information technology and electronics Mechanical structures Deep-sea infrastructure Deployment Calibration
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Design rationale:
Cost-effectiveReliableProducableEasy to deployBuilds on the experience
gained with ANTARES, NEMO and NESTOR
P. Sapienza, NOW 2010
Other issues addressed in the Design Study
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Site characteristics Measure site characteristics (optical properties and optical
background, currents, sedimentation, …) Simulations
Determine detector sensitivity, optimise detector parameters Earth and Sea science requirements
Define the infrastructure needed to implement multidisciplinary science nodes
P. Sapienza, NOW 2010
Single PMT Optical Module
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8” PMT with 35% quantum efficiency inside a 13” glass sphere good timing evolution from pilot projects => well known technology
P. Sapienza, NOW 2010
Multi-PMT Optical Module
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31 3” PMTs inside a 17” glass sphere with 31 bases (total ~140 mW) Cooling shield and stemFirst full prototype end of 2010
Single vs multi photon hit separationLarger photocade area per OM
P. Sapienza, NOW 2010
TDR - Detection Unit concepts
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Flexible tower with horizontal bars equipped with single-PMTs or multi-PMT OMs
Triangular arrangements of OMs with single-PMTs or multi-PMT
Evolution of the ANTARES storey
Slender stringVertical sequence of multi-PMTs OMs
Simulations indicate that local 3D OM arrangement resolve ambiguities in the reconstruction of the muon azimuthal angle
DUs are the mechanical structures that hold OMs, enviromental sensors, electronics,…
P. Sapienza, NOW 2010
Deployment strategy
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Compact package & Self unfurling => easy logistics that speeds up and eases deployment
Connection to seabed network by Remotely Operated Vehicle
Spherical deployment structure for string with multi-PMT OM
The packed flexible tower
Successful deployment test in February 2010 Successful deployment
test in December 2009
P. Sapienza, NOW 2010
KM3NeT performance
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☐Quality Cuts applied (0.2°@30TeV) Quality Cuts optimized for sensitivity
Up-going neutrino Effective Area Detector resolutionMedian of DW n-mrec
n
mq n-m
P. Sapienza, NOW 2010
TDR- KM3NeT Sensitivity & Discovery potential
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KM3NeT sensitivity 90%CLKM3NeT discovery 5s 50%IceCube sensitivity 90%CLIceCube discovery 5s 50% 2.5÷3.5 above sensitivity flux. (extrapolation from IceCube 40 string configuration)
binned method
unbinned method
| Observed Galactic TeV-g sources (SNR, unidentified, microquazars) F. Aharonian et al. Rep. Prog. Phys. (2008)Abdo et al., MILAGRO, Astrophys. J. 658 L33-L36 (2007) Galactic Centre
Sensitivity and discovery fluxes for point like sources with a E-2 spectrum for 1 year of observation time (full detector 154 DUx2)
Observation of RXJ1713 at 5swithin about 5 years
Sensitivity and discovery potential will improve with unbinned analysis
P. Sapienza, NOW 2010
Developments after the TDR Major effort towards the construction and validation of
pre-production model of the DU underway Bar with horizontal extent
Optimised design and plan for extensive deployment tests defined Multi-PMT Optical Module
Development plan for validation of technology and validation procedure defined
Optimization of simulation of the detector performance ongoing
Deployment of first prototype DU planned end 2011
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P. Sapienza, NOW 2010
Packaging of a tower with 20 storey for compact deployment
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6 m
1.1 m
2.6
m
P. Sapienza, NOW 2010
Concluding remarks
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The KM3NeT TDR is a major milestone for KM3NeT
Km3NeT detector volume will be about 5 km3
KM3NeT activities, together with the success of the pilot projects, puts the project on a firm ground
KM3NeT will cover a large fraction (87%) of the sky with a sensitivity and discover potential that will be better than any other neutrino telescope
P. Sapienza, NOW 2010
Concluding remarks
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Major impact also on the deep-sea sciences Technological solutions developed by KM3NeT modified the state-of-
the-art for deep-sea sciences Strong synergies with the EMSO project
Collaboration with INGV and IFREMER already active at the Catania and Toulonsites
Significant acceleration of the convergence process towards a unique technical solution
Final prototyping process will be coordinated within the Preparatory Phase