The ANTARES submarine neutrino telescope

Abstract

The European Collaboration ANTARES (Astronomy with a neutrino telescope and abyss environmental research) is building and operating a large undersea neutrino telescope located in the Mediterranean Sea, offshore from Toulon in France. This water Cherenkov detector is optimized for the detection of muons from high-energy astrophysical neutrinos and will open a new window on the universe. It is, at present, the largest neutrino telescope currently under construction in the northern hemisphere [1]. The telescope is based on the reconstruction of the trajectory and energy of neutrinos by detecting the Cherenkov light from muons, particles produced in neutrino interactions. Since the neutrino interaction probability is very low, only some of them will interact, and in order to have a sufficient number of events a huge volume of detection is required. The angular resolution is expected to be less than 0.3deg at high energies (E>10TeV) for the ANTARES detector. To achieve this good angular resolution, the detector is designed such that electronics contributions contribute less than -0.5 ns to the time resolution of the detected photons. In addition, the relative position reconstruction of the Optical Module, mainly based on the acoustic positioning system, is controlled with a precision of ~10 cm. The detector is located at a depth of 2500 m to provide a water shield from other cosmic rays which have larger interaction probabilities than neutrinos. An instrumented line is deployed at the edge of the detector to monitor environmental sea parameters. At present there are 9 lines and a new instrumented line deployed in the sea: 5 are connected and give data; the remaining lines will be connected in the coming months. This paper describes the design of the detector as well as some results obtained.