(NEutrino Mediterranean Observatory): Toward a km3 Neutrino Telescope NEMO (NEutrino Mediterranean Observatory): Toward a km3 Neutrino Telescope in the Mediterranean Sea Marco Circella Istituto Nazionale di Fisica Nucleare Bari, Italy on behalf of the NEMO Collaboration Il “Toward” è stato aggiunto dopo la conferenza... (perciò non figura nel titolo dell’abstract né nei proceedings)

(NEutrino Mediterranean Observatory): Toward a km3 Neutrino Telescope NEMO (NEutrino Mediterranean Observatory): Toward a km3 Neutrino Telescope in the Mediterranean Sea What we will be talking about: a km3 Neutrino Telescope in the Mediterranean Sea? R&D for a km3 Neutrino Telescope the site selection the NEMO apparatus: the “tower” approach Prototyping activity: NEMO-Phase 1 and 2

Motivations for a km3 Neutrino Telescope in the Mediterranean Sea No doubt we need a km3 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

Constraints for a km3 Neutrino Telescope in the Mediterranean Sea detector installation is an issue optical background in sea-water due to 40K-decay and bioluminescence the apparatus is not rigid in the sea currents high-pressure salted water is not a friendly environment...

Solutions for a km3 Neutrino Telescope in the Mediterranean Sea 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 40K 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

NEMO R&D activities toward a km3 Detector 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

see Tommaso Chiarusi’s presentation NEMO km3 Optimal site 80 km NEMO-KM4 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,... 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 Huge apparatus of more than 1 km side and 800 m tall see Tommaso Chiarusi’s presentation

NEMO km3 Telescope layout Tower Secondary JB Electro-optical cable to shore Primary JB 1120-1440 m NEMO km3 proposal: 10 junction boxes, 81 towers, 5832 PMTs

The tower approach (and design) 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 “Folded” tower for transportation and deployment A tower floor 16 m 2 PMTs at each edge NON mostrata per mancanza di tempo

The NEMO simulated performance 106107 GeV 103104 GeV 104105 GeV 105106 GeV NON mostrata per mancanza di tempo Muon effective area Neutrino effective area Median angle between muon simulated and reconstructed track

The Tower deployment Remark: the tower design has been performed in tight connection with leading underwater operation companies

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

The NEMO prototyping activities 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 Geoseismic station SN-1 (INGV) The Catania test site: 25 km off the coast of Catania 2000 m depth already equipped with a double-termination cable 80 km 25 km Catania TSS TSN NEMO-KM4 NEMO Phase 1 Il progetto prevede la realizzazione del dimostratore tecnologico di km3 al largo delle coste di Catania. Nel sito di installazione di Catania verranno depositati sul fondo del mare le 3 jb e la minitorre. La torre modello nemo di 16 piani verrà installata a capo passero dopo il deployment del cavo

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) (see Giorgio Riccobene’s presentation)

Installation of the cable termination panels at the test site (January 2005) ROV connection

schedule: to be completed in 2006 NEMO Phase 1 Purpose: to test all critical components for the construction of the km3 detector Structure: it comprises a junction box and a reduced-size tower (4 floors with 16 PMTs) schedule: to be completed in 2006

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)

Conclusions & perspectives The NEMO Collaboration is working on a long-term R&D program toward the construction of a km3 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 km3 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 km3 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 to be held in Catania, 8-11 Nov. 2005 Probabilmente converrebbe aggiungere una riga all’ultimo punto “Working for...” dove si parla della collaborazione in atto con ANTARES