The BAIKAL Neutrino Telescope
The underwater neutrino telescope NT200 is located in the Siberian lake Baikal at a depth of approximately 1 km. Deployment and maintenance of the Baikal detector is carried out during the winter months, when the lake is covered with a thick ice sheet. From the ice surface, the optical sensors can easily be lowered into the water underneath. Once deployed, the optical sensors take data over the whole year and the data taken are permanently transmitted to the shore over electrical cables.
The BAIKAL experiment played a pioneering role in neutrino astronomy: During spring 1993, scientists from Russian institutes and from DESY were the first to install an underwater telescope which took data not only for some hours, but for a whole year. At that time, the detector comprised only three strings carrying 36 optical sensors in total. Since 1998 the Baikal collaboration takes data with the NT200 telescope which consists of 192 optical sensors deployed on eight strings.
Scientists from DESY Zeuthen have been participating in the experiment from 1988 to 2008.
Currently, Russian groups are working on technologies to build a km3-size telescope in Lake Baikal, which might be installed starting from 2013.