The optical module of the Baikal deep underwater neutrino telescope

A deep underwater Cherenkov telescope has been operating since 1993 in stages of growing size at 1.1 km depth in Lake Baikal. The key component of the telescope is the Optical Module (OM) which houses the highly sensitive phototube QUASAR-370. We describe design and parameters of the QUASAR-370, the layout of the optical module, the front-end electronics and the calibration procedures, and present selected results from the five-year operation underwater. Also, future developments with respect to a telescope consisting from several thousand OMs are discussed.Comment: 30 pages, 24 figure

The optical module of the Baikal deep underwater neutrino telescope

A deep underwater Cherenkov telescope has been operating since 1993 in stages of growing size at 1.1 km depth in Lake Baikal. The key component of the telescope is the optical module (OM) which houses the highly sensitive phototube QUASAR-370. We describe design and parameters of the QUASAR-370, the layout of the optical module, the front-end electronics and the calibration procedures, and present selected results from the five-year operation underwater. Also, future developments with respect to a telescope consisting from several thousand OMs are discussed. (orig.)19 refs.Available from TIB Hannover: RA 2999(98-091) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

The BAIKAL Neutrino Telescope: From NT200 to NT200+.

We review the status of the Baikal Neutrino Telescope, which has recently been upgraded to the 5 Mton detector NT200+. We present results on searches for upward going atmospheric neutrinos and relativistic magnetic monopoles, obtained from 1998-2002 with the predecessor detector NT200. A search for very high energy neutrinos yields an upper limit on the extraterrestrial diffuse neutrino flux for 20 TeV < E < 50 PeV. We describe the strategy of upgrading NT200 to NT200+ and creating a detector on the Gigaton (km3) scale at lake Baikal. R&D activities on that next stage detector have been started

High-energy astrophysics with neutrino telescopes

Neutrino astrophysics offers new perspectives on the Universe investigation: high energy neutrinos, produced by the most energetic phenomena in our Galaxy and in the Universe, carry complementary (if not exclusive) information about the cosmos with respect to photons. While the small interaction cross section of neutrinos allows them to come from the core of astrophysical objects, it is also a drawback, as their detection requires a large target mass. This is why it is convenient put huge cosmic neutrino detectors in natural locations, like deep underwater or under-ice sites. In order to supply for such extremely hostile environmental conditions, new frontiers technologies are under development. The aim of this work is to review the motivations for high energy neutrino astrophysics, the present status of experimental results and the technologies used in underwater/ice Cherenkov experiments, with a special focus on the efforts for the construction of a km3 scale detector in the Mediterranean Sea.Comment: 88 pages and 41 figure