The Lake BAIKAL Neutrino Project: Status Report

A first large deep underwater detector for muons and neutrinos, NT-200, is currently under construction in Lake Baikal. Part of the detector consisting of 36 optical modules (NT-36) has been operated over nearly 2 years in 1993 and 1994. With this detector not only methodical questions are investigated, but also some problems in the field of astroparticle physics, cosmic ray physics and limnology. In March 1995, a 72-PMT version was deployed. We describe the construction of the detector and the present status of the project and review some of the results. 1 The NT-200 Detector The Baikal Neutrino Telescope [1] is being deployed in the Siberian Lake Baikal, about 3.6 km from shore at a depth of 1.1 km. In April 1993 we put into operation the stationary 3-string detector NT-36, since April 1994 a modified version of NT-36 was taking data. An array carrying 72 PMTs has been deployed in March 1995. These arrays are steps towards the Neutrino Telescope NT-200 which will consist of 192 opti..

Preliminary results on a search for neutrinos from the center of the earth with the Baikal underwater telescope

The deep underwater Cherenkov neutrino telescope NT-200 is currently under construction at lake Baikal. Its first stage NT-36 consisting of 36 optical modules has operated over 2 years since April 1993 till March 1995. Here we present a method to search for nearly vertical upward going muons from neutralino annihilation in the center of the Earth. We present preliminary results obtained from experimental data taken with the NT-36 array in 1994

Search for neutrinos from the core of the earth with the Baikal Underwater Detector NT-36

The first stage of the Baikal Neutrino Telescope NT-200, the detector NT-36, was operated from 1993 to 95. The data obtained with this small array were analysed to search for vertically upward muons. Apart from neutrinos generated in the atmosphere at the opposite side of the Earth, such muons might be due to neutrinos produced in neutralino annihilations in the center of the Earth. We have selected two clear neutrino candidates. From this, an 90%CL upper limit of 1.3 x 10^-13 muons cm^(-2) sec^(-1) in a cone with 15 degree half-aperture around the opposite zenith is obtained for muons due to neutralino annihilation