A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC1 KM3NeT, a deep sea neutrino telescope in the Mediterranean Sea KM3NeT objectives The KM3NeT Design Study Outlook Anastasios Belias for the KM3NeT Consortium

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC2 A -telescope in the Mediterranean sea Complementarity with Ice Cube coverage We need Northern -telescope to cover the Galactic Plane

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC3 The KM3NeT Consortium Consists of 40 Institutes of 10 European States Includes expertise from all three precursor projects, ANTARES, NEMO, NESTOR Objectives –Build and operate an extensible km 3 -scale water Cherenkov neutrino telescope in the Mediterranean Sea –Sustain a deep-sea research infrastructure for earth and marine sciences KM3NeT, a multidisciplinary research infrastructure –Synergetic with European Multidisciplinary Seafloor Observatory (EMSO)

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC4 KM3NeT Objectives 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 The unexpected Earth and marine sciences –Long-term, continuous measurements in deep-sea –Marine biology, oceanography, geology/geophysics, …

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC5 The KM3NeT Design Study Supported by the European Union in FP6 with ~9M€, tot. value ~20M€. Timeline: Started on Feb. 1, 2006 and will end on Oct. 31, 2009 Conceptual Design Report published, April 2008 Technical Design Report by end of 2009 Detector Target Specifications: Effective volume ≥ 1km o angular resolution for muons (E ≥ 10TeV) Energy threshold few 100 GeV Field of view close to 4π for high energies

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC6 Deep-sea -Telescope at work Upward-going neutrinos interact in rock or sea water. Emerging charged particles (in particular muons) produce Cherenkov light in water. Detection by array of photomultipliers. Focus of scientific interest: Neutrino astronomy in the energy range 1 to 100 TeV.

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC7 A standard optical module, as used in ANTARES, NEMO, NESTOR Typically a single large diameter (10’’) PMT in a 17’’ glass sphere Optical Module: standard...

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC8 … or many small PMTs Use up to 31 small (3’’) PMTs in a standard 17’’ glass sphere –very high QE PMTs Advantages: –increased photocathode area –significant improved TTS –directionality –improved 1-vs-2 photo- electron separation  better sensitivity to coincidences Prototype tests underway

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC9 Electronics & Data Readout Concepts Front-end options studies New improved front-end chip in the deep-sea –New FPGA/CPU Minimize active electronics in deep-sea –Reflective optical modulator –on-shore timestamp Both options use fibers, Wavelength Division Multiplexing and Point-to- point networks “ALL DATA TO SHORE” Interlink cables Submarine Telecom cable

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC10 Shore station real-time processing ALL digitized PMT data are sent to shore Expected rate of ~ 100Gb/s cannot be stored Perform time - position correlations of photomultiplier hits Correlations in real-time for the whole telescope Data reduction factor: ~10000

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC11 Configuration studies Various geometries and OM configurations have been studied None is optimal for all energies and directions Local coincidence requirement poses important constraints on OM pattern

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC12 Mechanical structures -Flexible tower structure: Tower deployed in compactified “package” and unfurls thereafter -String structure: Compactified string at deployment, unfolding on sea bed

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC13 Deployment & Sea Operations Deployment with ships or dedicated platforms. Ships: Buy, charter or use ships of opportunity. Platform: Delta-Berenike, under construction in Greece Deep-sea submersibles –Remotely operated vehicles (ROVs) –Autonomous Undersea Vehicles (AUVs) under study Delta-Berenike: triangular platform, central well with crane, water jet propulsion All deployment options require ships or platforms with GPS and DP

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC14 Earth and Marine Sciences Associated science devices will be installed at various distances around neutrino telescope Issues addressed: –operation without mutual interference –interfaces –stability of operation and data sharing

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC15 The candidate sites Important Criteria Bioluminescence rate Biofouling Sedimentation Sea Currents Absorption length Depth Distance from Shore Access to shore facilities Long-term site measurements performed and ongoing Site decision requires scientific, technological and political input

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC16 NESTOR 4.5 D Site36 O ’ N / 21 O ’ E Site characterisation: Example Transmission length vs wavelength

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC17 KM3NeT Roadmap Design study Feb. 1, 2006 – Oct. 31, 2009 –Produced Conceptual Design Report –Will produce Technical Design Report (by end. 2009) “Preparatory Phase” EU funded ~5M€, tot. ~10M€ 3/2008 – 2/2011 –Initiate political process towards convergence and legal structure –Prepare operation organisation & user communities –System prototypes –Commitment of funding agencies Site selection around 2010 ? Construction Phase –Start on extendable km 3 –scale neutrino telescope

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC18 KM3NeT Technical Design Report will address key issues Maximize physics output for given budget: Which architecture and structure to use? –String vs Tower concept How to get the data to shore? –Electronics off-shore or on-shore How to calibrate the detector? –Separate calibration and detection units Design of photo-detection units? –Large vs several small PMTs Deployment technology? –Dry vs wet ROV/AUV vs hybrid

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC19 Outlook Joint efforts of ANTARES, NEMO, NESTOR to build a km 3 -scale neutrino telescope in the Mediterranean Sea The Technical Design Report will be ready by end 2009 The Preparatory Phase started Towards construction to start in The km 3 -scale neutrino telescope in the Mediterranean Sea will complement IceCube in its field of view

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC20

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC21 Backup slides

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC22 Simulations of 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 with 21 3’’ PMTs This is NOT the final KM3NeT design! Effective area of reference detector

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC23 Point source sensitivity Based on muon detection Why factor ~3 more sensitive than IceCube? –larger photo- cathode area –better direction resolution Study still needs refinements

A. BELIAS, NESTOR Institute, Pylos, Greece TeVPA 2009, July 13-17, SLAC24 Diffuse fluxes Assuming E -2 neutrino energy spectrum Only muons studied Energy reconstruction not yet included