1. The NEMO Status Report M.Taiuti on behalf of the NEMO Collaboration Merida, Yucatan, Mexico 30th International Cosmic Ray Conference July 3 - 11, 2007

2. The NEMO Collaboration INFN • Bari, Bologna, Catania, Genova, LNF, LNS, Napoli, Pisa, Roma • Universities • Bari, Bologna, Catania, Genova, Napoli, Pisa, Roma “La Sapienza” CNR • Istituto di Oceanografia Fisica, La Spezia • Istituto di Biologia del Mare, Venezia • Istituto Sperimentale Talassografico, Messina Istituto Nazionale di Geofisica e Vulcanologia (INGV) Istituto Nazionale di Oceanografia e Geofisica Sperimentale (OGS) Istituto Superiore delle Comunicazioni e delle Tecnologie dell’Informazione (ISCTI) more than 80 researchers involved

3. ANTARES Toulon 2400 m NEMO Capo Passero 3400 m NESTOR Pylos 4000 m A Northern Telescope for High Energy Neutrinos • The small cross section and the expected low neutrino flux require • large volume telescope ~ 1 km3 • long observation time ~ yrs • The atmospheric muon background requires • a shielding > 2000 m water equivalent • The Mediterranean Sea provides convenient sites

4. Catania INFN-LNS TSN TSS 80 km NEMO R&D Activity • Site location • More than 25 sea campaigns since 1998 • NEMO-KM4 • 80 km off-shore • 3500 m depth NEMO-KM4

5. -3000 m NEMO-KM4 Properties • High water transparency • Data compatible with pure salt water properties • No seasonal variations • Reduced background, mostly from 40K decay • 10” PMT thres. 0.5 p.e. noise rate ~ 30 kHz • Bioluminescence almost absent • Geologically stable

6. NEMO km3 Conceptual Design

7. Tower Secondary JB Primary JB 140-180 m Electro-optical cable to shore 140-180 m NEMO km3 Conceptual Design • Proposed lay-out • 10 junction boxes • 81 towers • 5832 PMTs

8.  NEMO search bin 0.3°  IceCube search bin 1° Sensitivity to a E-2 neutrino spectrum from a pointlike source The Expected Performances • Simulations show excellent angular resolution and sensitivity • NEMO • 81 towers 140 m spaced • 5832 PMTs • ICECUBE • 80 strings 125 m spaced • 4800 PMTs IceCube simulations from Ahrens et al. Astrop. Phys. 20 (2004) 507

9. Single armored cable 20.595 km North branch 5.220 km Double armored cable 2.330 km South branch 5.000 km Frame Junction Box Tower Jumpers 300m Jumper 300m The NEMO Phase-1 Activity Geoseismic station SN-1 station (INGV) Operating since Jan 2005 BU NEMO Phase-1 OnDE acoustic station Operating from Jan 2005 till Dec 2006 NEMO Phase-1 Operating since 16 Dec 2006

10. Electronics Successfully deployed Dec. 10, 2006 The NEMO Junction Box Marine Alum. external frame • Innovative design to decouplethe corrosion and pressureresistance problems Transformer Electro-optical connectors Electro-optical splitting box Glass reinforced plastic container

11. Buoy br FCM FPM Floor 4 ADCP FPM FCM br Floor 3 C* br FCM FPM Floor 2 CTD FPM FCM br Floor 1 OM OM Tower Base H AB H TBM HC The NEMO Prototype Tower • 4 floors • Length 15 m • Vertical spacing 40 m • 16 Optical Modules with 10” PMT • Acoustic Positioning • 2 hydrophones per floor • 1 beacon on the tower base • Environmental instrumentation • 1 compass + tiltmeter in each Floor Control Module • CTD (Conductivity-Temperature-Depth) probe on floor 1 • C* (attenuation length meter) on floor 2 • ADCP (Acoustic Doppler Profiler (including compass) on floor 4

12. 4 floors Successfully deployed Dec. 15, 2006 “Folded” tower ready for transportation and deployment Successfully connected Dec. 16, 2006 The NEMO Tower • Semi-rigid structure provides “easy” assembly, transportation and deployment • The 4-floor prototype has been successfully deployed and is operating since Dec. 16, 2006

13. 250 m 350 m  ≈ 1.5 ns Calibration - Preliminary Results • Absolute positioning • Long Baseline acoustic positioning system based on five Acoustic Beacons • 3 autonomous beacons battery operated • 1 beacon on the Junction Box (not operating) • 1 beacon on the Tower base • Time offset determination • network of optical fibres to flash several OMs at one time with fast LED light pulses

14. Preliminary Results • Systematics over one month shows good water properties:  baseline rate  burst fraction evaluated as time above 1.2xbaseline  burst fraction evaluated as time above 200 kHz • The Tower can recontruct atmospheric muon tracks! • January 24 2007 - Run R17 file 1 Event # 366059 13 PMT hit

15. NEMO-KM4 80 km to NEMO-KM4 The NEMO Phase-2 • Infrastructures for an -3500 m underwater site • Electro-optical cable (50 kW – 20 fibres) • Deployment scheduled in summer 2007 • Deployment of DC/DC Converter beginning 2008 • Shore station in PortoPalo di Capo Passero • Building under renovation. Completion beginning 2008 • NEMO Tower • Deployment forseen by middle 2008

16. Conclusions and Perspectives • The NEMO Collaboration is working on a long-term R&D program toward a km3-telescope in the Mediterranean Sea • An optimal candidate site has been found: NEMO-KM4 • The NEMO Phase-1, aiming to validate the proposed technologies, has been successfully conducted at the Catania Test Site • Since Jan. 2005 the geoseismic and acoustic stations are fully operative • The Junction Box and the mini-Tower has been deployed at the end of 2006 • Data taking is in progress • The NEMO Phase-2, aiming to realize the deep sea station at NEMO-KM4, is in progress • The deployment of the electro-optical cable is scheduled in 2007 • The set-up of the onshore station is in progress • The deployment of a full-size tower is foreseen in 2008

17. Toward the -Telescope • EU funded the joint activity for a European-scale Design Study for a km3-telescope in the Mediterranean Sea • KM3NeT: ANTARES-NEMO-NESTOR consortium http://www.km3net.org/ • The experience gained will contribute to the advancement of the KM3NeT activities