Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
KM3NeT: a deep-sea neutrino telescope in the Mediterranean Sea
Paolo Piattelli - INFN/LNS Catania (Italy)on behalf of the KM3NeT Consortium
Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
What is KM3NeT ?• An acronym for km3 Neutrino Telescope• A future deep-sea Research Infrastructure hosting a km3 scale
neutrino telescope and facilities for associate marine and earth sciences
• A Consortium between the groups/Institutions that have developed the pilot neutrino telescope projects in the Mediterranean Sea (Antares, Nemo, Nestor)– Two projects funded by the EU– Design Study (2006-2009): aims at developing a cost-effective
design for the construction of a 1 km3 neutrino telescope– Preparatory Phase (2008-2010): preparing for the construction
by defining the legal, financial ad governance issues as well as the pre-production of the telescope components
Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
Timeline towards construction
Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
KM3NeT Conceptual Design Report
Will soon be available on the KM3NeT consortium web sitehttp://www.km3net.org
Will soon be available on the KM3NeT consortium web sitehttp://www.km3net.org
Describes the scientific objectives, and the concepts behind the design, construction, and operation of the KM3NeT Research Infrastructure
Describes the scientific objectives, and the concepts behind the design, construction, and operation of the KM3NeT Research Infrastructure
Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
Science case
• Astroparticle physics with neutrinos– “Point sources”: Galactic and extragalactic sources of
high-energy neutrinos
– The diffuse neutrino flux
– Neutrinos from Dark Matter annihilation
• Search for exotics– Magnetic monopoles
– Nuclearites, strangelets, …
• Neutrino cross sections at high(est) energies
• Earth and marine sciences– long-term, continuous measurements in deep-sea
– marine biology, oceanography, geology/geophysics, …
Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
Why in the Mediterranean Sea?
> 25% Visibility
> 75% Visibility
Observed sky region in galactic coordinates assuming efficiency for downwardhemisphere.
Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
Design goals
• Sensitivity to exceed IceCube by “substantial factor”• Core process:
+N +X at neutrino energies beyond 100 GeV
• Lifetime > 10 years without major maintenance, construction and deployment < 4 years
• Some technical specifications:– time resolution 2 ns– position of OMs to better than 40 cm accuracy– two-hit separation < 25 ns– false coincidences dominated by marine background– coincidence acceptance > 50%– PM dark rate < 20% of 40K rate
Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
Reference detector
• Sensitivity studies with a common detector layout
• Geometry:
– 15 x 15 vertical detection units on rectangular grid,horizontal distances 95 m
– each carries 37 OMs, vertical distances 15.5 m
– each OM with21 3’’ PMTs
NOT the finalKM3NeT design!
Effective areaof reference
detector
Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
Point source sensitivity
• Based on muon detection
• Factor ~3 more sensitive than IceCube– larger photo-
cathode area– better direction
resolution• Study still needs
refinements
Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
Diffuse fluxes
• Assuming E-2
neutrino energy
spectrum
• Only muonsstudied
• Energy reconstruction not yet included
Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
Configuration studies
• Various geometries and OM configurations have been studied
• None is optimal for all energies and directions• Local coincidence requirement poses important
constraints
Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
KM3NeT CDR contents
1. Introduction
2. Science case
3. The KM3NeT concept
4. Neutrino telescope design goals
5. Pilot projects
6. Site investigations
7. Technical implementation
8. Development plan
9. Project implementation
1. Introduction
2. Science case
3. The KM3NeT concept
4. Neutrino telescope design goals
5. Pilot projects
6. Site investigations
7. Technical implementation
8. Development plan
9. Project implementation
7.1. Optical modules
7.2. Information technology
7.3. Mechanics
7.4. Deep-sea and shore infrastructures
7.5. Deployment
7.6. Calibration
7.1. Optical modules
7.2. Information technology
7.3. Mechanics
7.4. Deep-sea and shore infrastructures
7.5. Deployment
7.6. Calibration
Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
Optical ModulesStandard or directional …Standard or directional …
Segmentation of photo cathode of 10” PMT
Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
Optical Modules… or many small PMTs …… or many small PMTs …
• Basic idea: Use up to 30 small (3’’ or 3.5’’) PMTs in standard sphere
• Advantages: – increased photocathode area– improved 1-vs-2 photo electron
separation better sensitivity to coincidences
– directionality• Prototype arrangements under
study
Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
Optical Modules… or hybrid solutions …… or hybrid solutions …
• Idea: Use high voltage (~20kV) and send photo electrons on scintillator;detect scintillator light with small standard PMT.
• Advantages:– Very good photo-electron
counting– large angular sensitivity
possible• Prototype development in
CERN/Photonis/CPPM collaboration
Quasar 370(Baikal)
Paolo Piattelli - KM3NeTPaolo Piattelli - KM3NeT IAPS - Golden, 6-8 may 2008IAPS - Golden, 6-8 may 2008
Mechanical structures
- Extended tower structure: NESTOR like, arm length up to 60 m
- Flexible tower structure: NEMO like, tower deployed in compactified “package” and unfurls thereafter
Four options consideredFour options considered
- String structure: Compactified at deployment, unfolding on sea bed
- Cable based concept: one (large) OM per storey, separate mechanical and electro-optical function of cable, compactified deployment
Tower likeTower like
String likeString like