1. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 The NEMO Project (NEutrino Mediterranean Observatory): Toward a km 3 Neutrino Telescope in the Mediterranean Sea Marco Circella Istituto Nazionale di Fisica Nucleare Bari, Italy marco.circella@ba.infn.it on behalf of the NEMO Collaboration The NEMO presentations are dedicated to the memory of Prof. Carlo De Marzo

2. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 The NEMO Project (NEutrino Mediterranean Observatory): Toward a km 3 Neutrino Telescope in the Mediterranean Sea What we will be talking about: a km 3 Neutrino Telescope in the Mediterranean Sea? the NEMO Project: R&D for a km 3 Neutrino Telescope the site selection the NEMO apparatus: the “tower” approach prototyping activity: NEMO-Phase 1 and 2

3. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 Photons absorbed on dust and radiation Protons deviated by magnetic fields Neutrinos direct Neutrino Astronomy

4. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 relics from Big Bang natural radioactive decay in Earth nuclear reactors explosions of supernova remnants of supernova from nuclear reactions in Sun interactions of cosmic rays in atmosphere Active Galactic Nuclei Neutrino energy (eV) Neutrinos arriving at Earth

5. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 Underwater/underice neutrino telescopes Cherenkov photons

6. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 Neutrino Telescope Projects ANTARES, Toulon, France BAIKAL: Lake Baikal, Siberia DUMAND, Hawaii (cancelled 1995) AMANDA/ICECUBE, Antarctica NESTOR, Pylos, Greece NEMO, Capo Passero, Italy

7. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 No doubt we need a km 3 detector for -astrophysics! Then: a Mediterranean detector will complement the ICECUBE sky survey crosschecks between the two detectors will be possible it will be possible to observe the Galactic center Motivations for a km 3 Neutrino Telescope in the Mediterranean Sea

8. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 detector installation is an issue optical background in sea-water due to 40 K-decay and bioluminescence the apparatus is not rigid in the sea currents high-pressure salted water is not a friendly environment... Constraints for a km 3 Neutrino Telescope in the Mediterranean Sea

9. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 detector installation is an issue keep the number of structures to a minimum, prepare structures which can be easily transported and deployed (the “tower” approach!) optical background in sea-water due to 40 K and bioluminescence choose a suitable site!!! the apparatus is not rigid in the sea currents position monitoring system needed high-pressure salted water is not a friendly environment... low-cost solutions need to be developed for mechanical structures Solutions for a km 3 Neutrino Telescope in the Mediterranean Sea

10. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 R&D for selected items: low-consumption Front-End electronics large area hybrid photomultiplier material choice and design of mechanical structures time calibration through a dedicated optical fibre system Commercial solutions when available: high-bandwidth SDH data communication system Dense Wavelength Division Multiplexing (DWDM) cables and connectors power distribution acoustic positioning system NEMO R&D activities toward a km 3 Detector See Martino Ruppi’s presentation

11. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 Huge apparatus of more than 1 km side and 800 m tall NEMO km Optimal site NEMO km 3 Optimal site 1 primary Junction Box 8-9 secondary Junction Boxes 64-81 towers 140 m grid pitch 64-72 PMT on each tower 4096-5832 PMT in total 80 km at SE of Capo Passero, Sicily 3500 m depth more than 25 sea campaigns for characterization since 1998 very good characteristics as to: water optical properties, sea currents, optical background, sedimentation,... 80 km NEMO-KM4

12. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 Water Optical Properties Negligible seasonal dependence of optical parameters in NEMO abyssal site Seasonal dependence of oceanographical (Temperature and Salinity) and optical (absorption and attenuation) properties have been studied. Variations are only observed for depth less than 2500 m Average values 2850÷3250 m TemperatureSalinity a440c440 Data taken in: Aug 03 (2) Aug 02 (3) Mar 02 (4) May 02 (2) Dec 99 (2) L a = 66.3 m L c = 33.5 m

13. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 Absorption lengths measured at Capo Passero are compatible with optically pure sea water Large differences between Toulon and Capo Passero site are observed in the blue region Values measured with the ANTARES Test 3’ setup are in good agreement with the AC9 data Optical water properties measured in joint 2002 NEMO-ANTARES campaigns Tommaso Chiarusi 29 th ICRC, Pune 2005 Water Optical Properties

14. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 NEMO km Telescope layout NEMO km 3 Telescope layout 1120-1440 m NEMO km 3 proposal: 10 junction boxes, 81 towers, 5832 PMTs 80 km NEMO-KM4 140-180 m Tower Secondary JB Electro-optical cable to shore Primary JB

15. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 The tower approach (and design) A tower floor 16 m 2 PMTs at each edge “Folded” tower for transportation and deployment Semi-rigid structures, which can be “easily” assembled and packed 4 PMTs on each floor (two looking downwards, two looking horizontally) after installation, floors are kept mutually perpendicular PMT arrangement extensively investigated through simulations

16. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 The Tower deployment Remark: the tower design has been performed in tight connection with leading underwater operation companies

17. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 The Tower deployment: tests Installation and recovery test of a 1:5 4-floor tower performed in Spring 2004 mechanical properties of the tower and installation/recovery procedures extensively simulated installation and recovery test of a full-size 4-floor tower will be performed in Fall 2005

18. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 Geoseismic station SN-1 (INGV) NEMO Phase 1 The NEMO prototyping activities (Phase 1) The Catania test site: 25 km off the coast of Catania 2000 m depth already equipped with a double- termination cable Shore station in the port of Catania 2.5 km e.o. Cable with double steel shield 21 km e.o. Cable with single steel shield Branching Unit 5 km e.o. cable 5 km e.o. cable 80 km 25 km Catania TSS TSN NEMO-KM4

19. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 Installation of the cable termination panels at the test site (January 2005) Recovery of the two terminations of the cable Installation of the termination panels Deployment of the termination panels ROV-connection of the acoustic monitoring system ONDE ROV-connection of the geoseismic platform SN-1 (Remark: ONDE and SN-1 fully operational since January)

20. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 Installation of the cable termination panels at the test site (January 2005) ROV connection

21. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 NEMO Phase 1 Purpose: to test all critical components for the construction of the km 3 detector Structure: it comprises a junction box and a reduced-size tower (4 floors with 16 PMTs) schedule: to be completed in 2006

22. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 The NEMO Phase 2 project: building the infrastructures for a 3500 m deep-sea apparatus (& testing a full-size NEMO tower) -3500 m Interdisciplinary activities NEMO-KM4 Long-distance electro-optical cable: purchase in 2005, deployment in 2006 shore station in the port (acquired; work in progress)

23. The NEMO Project: Toward a km 3 Neutrino Telescope in the Mediterranean Sea M. Circella, INFN Bari NUPPAC-05, Nov. 2005 Conclusions & perspectives The NEMO Collaboration is working on a long-term R&D program toward the construction of a km 3 neutrino telescope in the Mediterranean Sea The NEMO Phase 1 project is ongoing at an underwater test site offshore Catania: - infrastructure (cable to shore, shore station) ready - junction box to be deployed in early 2006 - a reduced-size tower to be deployed in 2006 The NEMO Phase 2 project has also started at the optimal km 3 site: - work to equip the onshore station started - electro-optical cable to be purchased by the end of 2005, deployed in 2006 - full-size tower to be deployed in 2007 Working for the future neutrino telescope in the Mediterranean: - ANTARES-NEMO-NESTOR consortium in the KM3Net EU Design Study: - EU-sponsored activity for a European-scale Design Study for a km 3 neutrino telescope in the Mediterranean Sea: project accepted for funding - negotiations with EU about to start activity expected to start in early 2006 - 2nd VLVnT (Very Large Volume -Telescope) workshop held in Catania, 8-11 Nov. 2005