The KM3Net Consortium

1. The KM3Net Consortium Towards a km3-scale neutrino telescope in the Mediterranean Sea C. Distefano on behalf of the KM3NeT Consortium Istituto Nazionale di Fisica Nucleare Laboratori Nazionali del Sud

2. 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 • Included in the European Roadmap for Research Infrastructures of the ESFRI • A Consortium of 40 institutes from 10 European countries including all the groups 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 (2008-2011): preparing for the construction by defining the legal, financial ad governance issues as well as the production plans of the telescope components

3. Timeline towards construction

4. 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, …

5. KM3NeT Conceptual Design Report Describes the scientific  objectives, and the concepts  behind the design, construction, and operation of the KM3NeT Research Infrastructure Downloadable from the KM3NeT web site http://www.km3net.org/CDR/CDR-KM3NeT.pdf

6. Design goals • Core process: nm+N  m+X at neutrino energies beyond 100 GeV • Lifetime > 10 years without major maintenance, construction and deployment < 4 years • Sensitivity optimized in the TeV-PeV range • Angular resolution 0.1° (for nenergies above 100 TeV) • Sensitivity to exceed IceCube by “substantial factor” • Some technical specifications: • time resolution better than 2 ns • position of OMs to better than 40 cm accuracy • two-hit separation better than 25 ns • …

7. Reference detector • Sensitivity studies with a reference 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 Effective area of reference detector NOT the final KM3NeT design! angular resolution of 0.1° @ 30 TeV

8. Some proposed geometries 169 NEMO Towers. Square array of 13x13 towers 140m apart. Tower consists of a sequence of 18 rigid bars, 20m length, 40 m vertically spaced and equipped with 4 10” PMTs two at each bar end, one down looking and the other horizontally looking. The bars are orthogonal one with respect to the near one. V~1.9 km3 169 towers 10” PMTs with max QE of 35% at 380nm 169 towers 10” PMTs with max QE of 43% at 390nm from CDR. Reference detector with 3” PMTs with max QE of 33% at 390nm. Quality cuts applied to reach an angular resolution of 0.1° @ 30 TeV

9. Point source sensitivity • Based on muon detection • Factor ~3 more sensitive than IceCube • larger photo-cathode area • better direction resolution • Study still needs refinements

10. Optical Modules With improved photocatode QE Standard One large area PMT with segmented photocatode Directional

11. Optical Modules Quasar 370 (Baikal) Many small (3’’ or 3.5’’) PMTs in standard glass sphere Multi PMT Use high voltage (~20kV) and send photo electrons on scintillator;detect scintillator light with small standard PMT Hybrid

12. Mechanical structures Two full designs were decided to be pursued: Monte Carlo simulations are in progress to choose the best solution Four options considered Tower like String like • cable-based designed: one (large) OM per storey (multi-PMT OMs); • all-optical readout; • separate mechanical and electro-optical function of cable • compactified at deployment, unfolding on sea bed • flexible structure; • large PMTs in clusters of 2 or more; • horizontal structures; • copper/optical readout; • deployed in compactified “package” andunfurls thereafter

13. Associated sciences • The KM3NeT infrastructure will serve as a platform for deep-sea and earth sciences • Strong synergy with the deep-sea science community • Associated sciencedevices will be installed at variousdistances aroundneutrino telescope • KM3NeT site in • ESONET (European Sea-floor Observatory NETwork) • EMSO (European Multi-disciplinary Sea-floor Observatory research infrastructure)

14. Candidate sites • Locations of thethree pilot projects: • ANTARES: Toulon • NEMO: Capo Passero • NESTOR: Pylos • All appear to besuitable • Long-term sitecharacterisationmeasurementsperformed and ongoing • Final decision concerning location and single vs multi-site option requiresscientific, technologicaland political input.

15. Summary and conclusions • The successful experience of the pilot projects demonstrated the feasibility of the km3 underwater high energy neutrino telescope • The KM3NeT consortium is progressing towards the completion of the Technical Design Report (2009) defining the technological solutions for the construction of a km3 n telescope in the Mediterranean Sea • The KM3NeT Preparation Phase started aiming at the definition of legal, financial and governance aspects • The KM3NeT detector in the Mediterranean Sea will complement IceCube in its field of view and exceed its sensitivity by a substantial factor • We are working towards a start of construction by 2011