PACS: 95.55.Vj 95.85.Ry 96.40.Tv a b s t r a c tWe present results of a search for relativistic magnetic monopoles with the Baikal neutrino telescope NT200, using data taken between April 1998 and February 2003. No monopole candidates have been found. We set an upper limit 4.6 Â 10 À17 cm À2 s À1 sr À1 for the flux of monopoles with b m = 1. This is a factor of 20 below the Chudakov-Parker bound which is inferred from the very existence of large-scale galactic magnetic fields.

We review the present status of the Baikal Neutrino Project. The construction and performance of the large deep underwater Cherenkov detector for muons and neutrinos, NT-200, which is currently under construction in Lake Baikal are described. Some results obtained with the first stages of NT-200 -NT-36 (1993-95), NT-72 (1995-96) and NT-96 (1996-97) are presented, including the first clear neutrino candidates selected with 1994 and 1996 data.

Abstract-A new analysis of the data from the NT200 neutrino telescope based on the reconstruction of parameters for high-energy showers generated in neutrino interactions has yielded new upper limits on the diffuse neutrino fluxes predicted by a number of theoretical models. The upper limit on the all-flavor neutrino flux with an energy spectrum E −2 is E 2 Φ ν < 2.

A prototype string for the future km 3 -scale Baikal neutrino telescope has been deployed in April, 2008 and is fully integrated into the NT200+ telescope. All basic string elements -optical modules (with 12"/13" hemispherical photomultipliers), 200MHz FADC readout and calibration system -have been redesigned following experience with NT200+. First results of insitu operation of this prototype string are presented. : 95.55.Vj, 95.85.Ry, 96.40.Tv PACS

We review the status of the Lake Baikal Neutrino Experiment. The Neutrino Telescope NT200 has been operating since 1998 and has been upgraded to the 10 Mton detector NT200+ in 2005. We present selected astroparticle physics results from long-term operation of NT200. Also discussed are activities towards acoustic detection of UHE-energy neutrinos, and results of associated science activities. Preparation towards a km3-scale (Gigaton volume) detector in Lake Baikal is currently a central activity. As an important milestone, a km3-prototype string, based on completely new technology, has been installed and is operating together with NT200+ since April, 2008.