The AMANDA-II Neutrino Telescope

To detect the feeble flux of predicted high energy astrophysical neutrinos, high energy Cherenkov neutrino telescopes are build as a grid of photomultiplier tubes (PMTs) covering a huge geometric volume. The density of PMTs per effective detector area is about 3 orders of magnitude below that for ν-events triggered in the SuperKamiokande detector; this implies a detailed verification of the anticipated performance of these new detectors. The AMANDA-II telescope is located at the geographic South Pole and uses the transparent ice of the 3 km thick ice sheet [1]. The detector has been installed between November 1995 and February 2000, and consists of 677 PMTs in optical modules (OM) on 19 vertical strings deployed to depths between 1300m-2400m. The main instrumented volume ranges from 1500m-2000m, it covers a cylinder of 200m diameter (fig.1). Strings 1-10 form the inner detector of 120m diameter called AMANDA-B10, which was commissioned in 1997. They use passive OMs with electrical analog signal transmission over 2 km cable. Strings 11-19 form the outer cylinder and are based on analog fiber transmission [2]. First physics results obtained with AMANDAB10 are presented at this conference by [3].