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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.

We present the formula for angular distribution of integral flux of conventional (π, K) muons deep under water taking into account the sphericity of the atmosphere and fluctuations of muon energy losses. The accuracy of this formula for various sea level muon spectra is discussed. The possibility of reconstructing two parameters of sea level spectrum by fitting measured underwater angular intensity is shown for Baikal Neutrino Telescope NT-36 experimental data.

We present a new Monte Carlo muon propagation algorithm MUM (MUons+Medium) which possesses some advantages over analogous algorithms presently in use. The most important features of algorithm are described. Results on the test for accuracy of treatment the muon energy loss with MUM are presented and analyzed. It is evaluated to be of 2×10 −3 or better, depending upon simulation parameters. Contributions of different simplifications which are applied at Monte Carlo muon transportation to the resulting error are considered and ranked. It is shown that when simulating muon propagation through medium it is quite enough to account only for fluctuations in radiative energy loss with fraction of energy lost being as large as 0.05÷0.1. Selected results obtained with MUM are given and compared with ones from other algorithms. PACS number(s): 13.85Tp, 96.40.Tv, 02.70Lq

We review the present status of the Baikal Neutrino Project. The construction and performance of the large deep underwater Cherenkov detector NT-200 with 192 PMTs , which is currently taking data in Lake Baikal, are described. Some results from intermediate detector stages are presented.