1. M.Taiuti on behalf of the NEMO Collaboration
The NEMO Status Report
M.Taiuti
on behalf of the NEMO Collaboration
Merida, Yucatan, Mexico
30th International Cosmic Ray Conference
July , 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. 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
NEMO
Capo Passero 3400 m
NESTOR
Pylos 4000 m
ANTARES
Toulon 2400 m

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

5. 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
-3000 m

6. NEMO km3 Conceptual Design

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

8. 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

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

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

11. The NEMO Prototype Tower
TBM
FPM
FCM br H OM
CTD AB C*
ADCP
Tower Base
Floor 1
Floor 2
Floor 3
Floor 4
Buoy HC
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. for transportation and deployment
The NEMO Tower
“Folded” tower ready
for transportation and deployment
4 floors
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

13. 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
350 m
250 m
 ≈ 1.5 ns

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 Run R17 file 1 Event # PMT hit

15. The NEMO Phase-2 Infrastructures for an -3500 m underwater site
80 km
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
to NEMO-KM4

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 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
The experience gained will contribute to the advancement of the KM3NeT activities