Neutrino Astronomy with KM3NeT

1. Vulcano Workshop 2008: Frontier Objects in Astrophysics and Particle PhysicsVulcano, Eolian Islands, Italy, May 25-31, 2008 Neutrino Astronomy with KM3NeT The KM3NeT physics case What happened so far The KM3NeT Conceptual Design Report The Preparatory Phase: Towards implementation Uli Katz ECAP / Univ. Erlangen 30.05.2008

2. The Neutrino Telescope World Map ANTARES + NEMO + NESTORjoin their efforts to preparea km3-scale neutrino telescope in the MediterraneanKM3NeT Design Study U. Katz: KM3NeT

3. What is KM3NeT ? • Future cubic-kilometre scale neutrino telescope in the Mediterranean Sea • Exceeds Northern-hemisphere telescopes by factor ~50 in sensitivity • Exceeds IceCube sensitivity by substantial factor • Focus of scientific interest: Neutrino astronomy in the energy range 1 to 100 TeV U. Katz: KM3NeT

4. protons E>1019 eV (100 Mpc) neutrinos gammas (0.01 - 1 Mpc) protons E<1019 eV Particle Propagation in the Universe Cosmic accelerator 1 parsec (pc) = 3.26 light years (ly) Photons: absorbed on dust and radiation; Protons/nuclei: deviated by magnetic fields, reactions with radiation (CMB) U. Katz: KM3NeT

5. The KM3NeT Field of View 2p downward sensitivity assumed Located inMediterranean  visibilityof givensource canbe limitedto less than 24h per day > 25% > 75% U. Katz: KM3NeT

6. Science Case Revisited • 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, … U. Katz: KM3NeT

7. 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 U. Katz: KM3NeT

8. n Flux Predictions from g Measurements • Kappes et al., astro-ph 0607286 Vela X (PWN) Note: hadronic nature of Vela X not clear! measured-ray flux (H.E.S.S.) mean atm. flux(Volkova, 1980, Sov.J.Nucl.Phys., 31(6), 784) expected neutrino flux –in reach for KM3NeT 1  error bands include systematic errors (20% norm., 10% index & cut-off) U. Katz: KM3NeT

9. Another Case: SNR RXJ1713.7-3946 • Good candidate for hadronic acceleration. • Expected signal well related to measured g flux, but depends on energy cutoff. • Few events/year over similar back-ground (1km3). • KM3NeT sensitivity in the right ballpark! U. Katz: KM3NeT

10. Potential Galactic Sources • The accelerators of cosmic rays • Supernova remnants • Pulsar wind nebulae • Micro-quasars • … • Interaction of cosmic rays with interstellar matter • Possibly strong n signal if CR spectrum harder in Galactic Centre than on Earth (supported by recent MILAGRO results) • Unknown sources – what are the H.E.S.S.”TeV gamma only” objects? U. Katz: KM3NeT

11. Potential Extragalactic Sources • AGNs • Models are rather diverse and uncertain • The recent Auger results may provide an upper limit / a normalisation point a UHE • Note : At some 100 TeV the neutrino telescope field of view is restricted downwards (n absorption), but starts to be significant upwards. • Gamma ray bursts • Unique signature: Coincidence with gamma observation in time and direction • Source stacking possible U. Katz: KM3NeT

12. Diffuse Fluxes • Assuming E-2neutrino energy spectrum • Only muonsstudied • Energy reconstruction not yet included U. Katz: KM3NeT

13. Dark Matter Sensitivity • Scan mSUGRAparameter spaceand calculateneutrino flux foreach point • Focus on pointscompatible withWMAP data • Detectability: • Blue: ANTARES • Green: KM3NeT • Red: None of them U. Katz: KM3NeT

14. KM3NeT: From the Idea to a Concept 11/2002 4/2008 2/2006 9/2006 9/2005 3/2004 First consultations of ANTARES, NEMO and NESTOR KM3NeT on ESFRI Roadmap The KM3NeT Conceptual Design Report Design Study proposal submitted KM3NeT on ESFRI List of Opportunities Begin of Design Study U. Katz: KM3NeT

15. Major Achievements to Date • Science & technology • Successful prototype deployments by NEMO and NESTOR • Installation and operation of ANTARES  A large deep-sea neutrino telescope is feasible! • Politics & funding • Endorsement by ESFRI and ApPEC • Funding through EU: Design Study, Preparatory Phase • Funding through national authorities:pilot projects, commitments for KM3NeT • Towards construction • Strong collaboration • Design concepts in CDR U. Katz: KM3NeT

16. 37 days with 5 lines ANTARES: Progress • String-based detector; • Downward-lookingphotomultipliers (PMs),axis at 45O to vertical; • 2500 m deep. • Currently taking data with 10 lines, completion imminent. 25 storeys, 348 m 14.5m 100 m Junction Box ~70 m U. Katz: KM3NeT

17. The KM3NeT Conceptual Design Report • Presented to public atVLVnT0 workshop in Toulon, April 2008 • Summarises (a.o.) • Physics case • Generic requirements • Pilot projects • Site studies • Technical implementation • Development plan • Project implementation available on www.km3net.org U. Katz: KM3NeT

18. The 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 Effective area of reference detector This is NOT the final KM3NeT design! U. Katz: KM3NeT

19. 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 U. Katz: KM3NeT

20. KM3NeT Design Goals • Sensitivity to exceed IceCube by “substantial factor” • Core process: nm+N  m+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 U. Katz: KM3NeT

21. Technical Implementation • Photo-sensors and optical modules • Data acquisition, information technology and electronics • Mechanical structures • Deep-sea infrastructure • Deployment • Calibration • Associated science infrastructure U. Katz: KM3NeT

22. Optical Modules: Standard or Directional • A standard optical module, as used in ANTARES • Typically a 10’’ PMT in a 17’’ glass sphere • A segmented anode and a mirror system allow for directional resolution • First prototypes produced U. Katz: KM3NeT

23. … or Many Small Photomultipliers … • 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 U. Katz: KM3NeT

24. Quasar 370 (Baikal) … 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, high quantum eff. • large angular sensitivity possible • Prototype development in CERN/Photonis/CPPM collaboration U. Katz: KM3NeT

25. Photocathode News • New photocathode developments by two companies (Hamamatsu, Photonis) • Factor 2 in quantum efficiency  factor 2 in effective photocathode area! • Major gain in neutrino telescope sensitivity! Hamamatsu Photonis U. Katz: KM3NeT

26. Mechanical Structures • Extended tower structure:like NESTOR, arm length up to 60 m • Flexible tower structure: like NEMO, tower deployed in compactified “package” and unfurls thereafter • 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 U. Katz: KM3NeT

27. The Associated Science Installation • Associated sciencedevices will be installed at variousdistances aroundneutrino telescope • Issues: • interfaces • operation withoutmutual interference • stability of operationand data sharing • Synergy effects U. Katz: KM3NeT

28. The Candidate Sites • Locations of thethree pilot projects: • ANTARES: Toulon • NEMO: Capo Passero • NESTOR: Pylos • All appear to besuitable • Long-term sitecharacterisationmeasurementsperformed and ongoing • Site decision requiresscientific, technologicaland political input U. Katz: KM3NeT

29. Site Characterisation: An Example Important parameter: water transparency Capo Passero Pylos (460 nm) Also: optical background, sea currents, sedimentation, biofouling, radioactivity, … U. Katz: KM3NeT

30. The KM3NeT Preparatory Phase • “Preparatory Phase”: A new EU/FP7 funding instrument restricted to ESFRI projects. • KM3NeT proposal endorsed, funded with 5 M€,coordinated by Emilio Migneco / LNS Catania • 3-year project, 3/2008 – 2/2011; kick-off meeting in Catania, 10-13 March 2008 • Major objectives: • Initiate political process towards convergence(includes funding and site selection/decision) • Set up legal structure and governance • Strategic issues: New partners, distributed sites, extendibility • Prepare operation organisation & user communities • Organise pre-procurement with commercial partners • Next-step prototyping U. Katz: KM3NeT

31. Timeline Towards Construction Note: “Construction” includes the final prototyping stage U. Katz: KM3NeT

32. Summary • Neutrinos would (and will) provide very valuable astrophysical information, complementary to photons and charged cosmic rays • Exploiting the potential of neutrino astronomy requires cubic-kilometre scale neutrino telescopes providing full sky coverage • 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 U. Katz: KM3NeT

33. Deep-sea infrastructure NEMO junction box design • Major components: • main cable & power transmission • network of secondary cableswith junction boxes • connectors • Design considerations: • cable selection likely to be drivenby commercial availability • junction boxes: may be custom-designed, work ongoingin NEMO • connectors: Expensive, reduce number and/or complexity U. Katz: KM3NeT

34. A green power concept for KM3NeT? • Idea: Use wind and/or solar power at KM3NeT shore installations toproduce the required electrical power. • Requires investment of 4-5 M€. • Can only work if coupled to a larger (public) power network. U. Katz: KM3NeT

35. Deployment: On the surface … • Deployment operations require ships or dedicatedplatforms. • Ships: Buy, charter or use ships of opportunity. • Platform: Delta-Berenike,under construction in Greece, ready summer 08 Delta-Berenike: triangular platform, central well with crane, water jet propulsion U. Katz: KM3NeT

36. … and in the Deep Sea Commercially available ROVs • Deep-sea submersibles are likely needed for • laying out the deep-sea cable network • making connections to detection units • possibly maintenance and surveillance • Remotely operated vehicles (ROVs) available for a wide range of activities at various depths • Use of autonomous undersea vehicles (AUVs) under study U. Katz: KM3NeT