Particle Astrophysics with the AMANDA neutrino telescope

• Published in: Annalen der Physik
• Main Author: Spiering, C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2001
• Subjects: South Pole; Ice Sheet; South pole
• Online Access: http://dx.doi.org/10.1002/andp.200151301-212; https://onlinelibrary.wiley.com/doi/pdf/10.1002/andp.200151301-212

Abstract Whereas MeV neutrin astronomy has been established by the observation of solar neutrinos and neutrinos from supernova SN1987, neutrinos with energies of GeV to PeV, which must accompany the production of high energy cosmic rays still await discovery. Detectors underground have turned ut to be too small to detect the feeble fluxes of energetic neutrinos from cosmic accelerators. The high‐energy frontier is being tackled by much larger, expandable arrays constructed in open water or ice. These telescopes detect the Cherenkov light generated by secondary particles – typically muons – produced in neutrino interactions. The Cherenkov radiation is detected by an array of photomultipliers which measures the arrival times of the photons to a precision of a few nanoseconds. Timing as well as amplitude information is used to reconstruct the track of the muon. To ensure that the muon is produced by a neutrino, the Earth is used as a filter: up‐going muon tracks can be generated only by neutrinos since this is the only particle which can pass through the Earth. Upgoing muons must be identified in an intense flux of downgoing muons. At 1 kilometer depth, the flux of downgoing (background) muons exceeds the upgoing signal by nearly six orders of magnitude. The Amanda neutrino detector consists of photomultipliers embedded at a depth of 1.5‐2.0 km in the ice sheet covering the geographic South Pole. The photomultipliers are housed in pressure glass spheres which are attached to vertical cable strings. With 677 photomultipliers at 19 strings, the present AMANDA‐II array reaches an effective detection area of a few 10 4 m 2 for 1 TeV muons. Although still far below the square kilometer size suggested by most theoretical models, AMANDA‐II may be the first detector with a realistic discovery potential for extraterrestrial high‐energy neutrinos. First physically relevant limits have been obtained from the analysis of data taken with the three times smaller AMANDA‐B10 in 1997. The limit on the diffuse flux from unresolved ...