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

 NEMO 2/17 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

 NEMO 3/17 A Northern Telescope for High Energy Neutrinos ► The small cross section and the expected low neutrino flux require  large volume telescope ~ 1 km 3  long observation time ~ yrs ► The atmospheric muon background requires  a shielding > 2000 m water equivalent ► The Mediterranean Sea provides convenient sites NEMO Capo Passero 3400 m NESTOR Pylos 4000 m ANTARES Toulon 2400 m

 NEMO 4/17 NEMO R&D Activity ► Site location  More than 25 sea campaigns since 1998 ► NEMO-KM4  80 km off-shore  3500 m depth 80 km NEMO-KM4 Catania INFN-LNS TSN TSS

 NEMO 5/17 NEMO-KM4 Properties ► High water transparency  Data compatible with pure salt water properties  No seasonal variations ► Reduced background, mostly from 40 K decay  10” PMT thres. 0.5 p.e. noise rate ~ 30 kHz  Bioluminescence almost absent ► Geologically stable

 NEMO 6/17 NEMO km 3 Conceptual Design

 NEMO 7/17 NEMO km 3 Conceptual Design ► Proposed lay-out  10 junction boxes  81 towers  5832 PMTs m Tower Secondary JB Electro-optical cable to shore Primary JB

 NEMO 8/17 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 NEMO search bin 0.3°  IceCube search bin 1° Sensitivity to a E -2 neutrino spectrum from a pointlike source

 NEMO 9/17 South branch km North branch km The NEMO Phase-1 Activity OnDE acoustic station Operating from Jan 2005 till Dec 2006 Junction Box Tower Frame Single armored cable km Double armored cable km BU NEMOPhase-1 Jumpers 300m Jumper300m Geoseismic station SN-1 station (INGV) Operating since Jan 2005 NEMO Phase-1 Operating since 16 Dec 2006

 NEMO 10/17 The NEMO Junction Box Electro-optical splitting box Glass reinforced plastic container Marine Alum. external frame Transformer Electronics Electro-optical connectors Successfully deployed Dec. 10, 2006 ► Innovative design to decouple the corrosion and pressure resistance problems

 NEMO 11/17 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

 NEMO 12/17 “Folded” tower ready for transportation and deployment 4 floors 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 Successfully deployed Dec. 15, 2006 Successfully connected Dec. 16, 2006

 NEMO 13/17 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  ≈ 1.5 ns 350 m 250 m

 NEMO 14/17 Preliminary Results ► Systematics over one month shows good water properties: baseline rate  baseline rate burst fraction evaluated as time above 1.2xbaseline  burst fraction evaluated as time above 1.2xbaseline burst fraction evaluated as time above 200 kHz  burst fraction evaluated as time above 200 kHz ► The Tower can recontruct atmospheric muon tracks!  January Run R17 file 1 Event # PMT hit

 NEMO 15/17 The NEMO Phase-2 80 km NEMO-KM4 to NEMO-KM4 ► Infrastructures for an 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

 NEMO 16/17 Conclusions and Perspectives ► The NEMO Collaboration is working on a long-term R&D program toward a km 3 -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 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

 NEMO 17/17 Toward the -Telescope ► EU funded the joint activity for a European-scale Design Study for a km 3 -telescope in the Mediterranean Sea  KM3NeT: ANTARES-NEMO-NESTOR consortium ► The experience gained will contribute to the advancement of the KM3NeT activities