Abstract

The *NEMO* (*NEutrino* Mediterranean Observatory) Collaboration aims at R&D for the construction of an underwater Cerenkov *neutrino* detector. Great attention is dedicated to projects for the apparatus electronics and
mechanical structures. At this stage the main eort of the collaboration is devoted to the selection and characterization of a marine site suitable for the detector deployment. Several sites near the Italian coast have been investigated. In addition, during year 2001, the collaboration will install a test site at 2000 m depth near the
Sicilian coast. The facility will be fundamental to study the deep sea environment and
to test the reliability of submersed structures.

1. Underwater Telescopes for *Neutrino* Astronomy In the last decade, the observation of cosmic rays of Very High Energy, Ultra High Energy, and even with energy greater than 1020 eV, has attracted the attention of the scientic community (Cronin et al., 1997). The sources of such events are supposed to be the most luminous and energetic objects observed in the universe such as Gamma Ray Bursters and Active Galactic Nuclei. The detection of intense extra galactic gamma ray sources with energy 10 TeV seems to conrm this hypothesis. If these high energy photons are generated through the production and decay of neutral pions, it is reasonable to expect, from the same sources, an associated ux of high energy neutrinos, generated through the production and decay of charged pions. It has been demonstrated that the GZK mechanism (Greisen, 1966) does not allow the observation of photons with energy

SOURCE: NEMO Home Page