Antares: Towards a large underwater neutrino experiment

After a long R&D phase to validate its detector concept, the ANTARES (Astronomy with a Neutrino Telescope and Abyss environmental RESearch) collaboration 1) is operating the largest neutrino telescope in the Northern hemisphere, which is close to completion. It is located in the Mediterranean Sea, offshore from Toulon in France at a depth of ∼ 2500 m of water which provide a shield from cosmic rays. The detector design is based on the reconstruction of events produced by neutrino interactions. The expected angular resolution for high energy νμ (E>10 TeV) is less than 0.3°. To achieve this good angular resolution, severe requirements on the time resolution of the detected photons and on the determination of the relative position of the detection devices must be reached. The full 12-line detector is planned to be fully operational during this year. At present (April 2008) there are 10 lines taking data plus an instrumented line deployed at the edge of the detector to monitor environmental sea parameters. This paper describes the design of the detector as well as some results obtained during the 2007 5-line run (from March to December). Copyright © 2008, by INFN.