The idea of deploying Cherenkov neutrino detectors in natural water reservoirs was proposed by Academician M. A. Markov and his student I. M. Zheleznykh. For the first time, it was presented at the Rochester Conference in 1960.
The first international project for constructing a neutrino telescope was DUMAND (Deep Underwater Muon And Neutrino Detector). The decision to deploy it in the Pacific Ocean near the Hawaiian Islands was made in 1976. However, already in 1995, the project was closed: the construction of the detector at a depth of 4800 m in open ocean turned out to be an exceptionally difficult undertaking.
The idea of using Lake Baikal to construct a prototype neutrino detector was proposed by Academician A. E. Chudakov. The lake has a number of advantages over the ocean. In winter, for about two months, it is covered with thick ice, and the ice is capable of supporting the heavy equipment needed to deploy the telescope. Optical properties of fresh Baikal water are perfectly suited for registering particles and determining their characteristics, such as the direction of arrival and energy.
The site for deploying the telescope was chosen according to several criteria, such as the availability of energy, railway, and shore infrastructure for powering the facility and the possibility of delivering large volumes of heavy equipment. The proximity of the lake's maximum depths to the shore was also taken into account.
It was decided to build the detector at the southern extremity of Lake Baikal, 3.6 km from the shore. Here the depth of the lake reaches 1366 m.
The first experimental string was deployed in 1986, and with its help scientists immediately obtained the first physical results.
The configuration of the telescope and the design of its basic detecting elements (glass spheres with photomultipliers and electronics inside – optical modules) were further developed. Registration methods and algorithms for data collection, transmission, and processing were refined.
In 1994, the still unfinished detector (which then consisted of only three incomplete strings) registered the world's first underwater neutrino.
The NT-200 neutrino telescope — the predecessor of the modern Baikal-GVD — was fully constructed by 1998. It contained eight vertical strings with 192 optical modules.
