The start of the Baikal neutrino experiment dates back to 1 October 1980, when a laboratory of high-energy neutrino astrophysics was established at the
Institute for Nuclear Research of the former Academy of Sciences of the USSR in Moscow. This laboratory would become the core of the Baikal collaboration. The original NT-200 design was deployed in stages 3.6 km from shore at a depth of 1.1 km. The first part,
NT-36 with 36 optical modules (OMs) at 3 short strings, was put into operation and took data up to March 1995.
NT-72 ran 1995–1996 then was replaced by the four-string
NT-96 array. Over its 700 days of operation, 320,000,000
muon events were collected with NT-36, NT-72, and NT-96. Beginning April 1997,
NT-144, a six-string array took data. The full
NT-200 array with 192 modules was completed April 1998. In 2004–2005 it was updated to
NT-200+ with three additional strings around NT-200 at distance of 100 meters, each with 12 modules.
Baikal-GVD Since 2016, a 1 cubic km telescope,
NT-1000 or
Baikal-GVD (or just
GVD,
Gigaton Volume Detector), is being built. The first stage of 3 strings was switched on in April 2013. During 2015 the
GVD demonstration cluster (also known as
Dubna) with 192 optical modules was successfully operated. This concluded the preparatory phase of the project. In 2016 the construction of the first phase of the telescope began with the demonstration cluster being upgraded to the baseline configuration for a single cluster, with 288 OMs on eight vertical strings. The first phase of the telescope, when completed, is expected to contain 8 such clusters. This first phase was expected to be completed around 2020. As of 2018, the Baikal telescope continued to operate and to be developed. On 13 March 2021, the first phase of the telescope,
GVD-I, was completed. It consisted of 8 clusters of 288 OMs each, and had a volume of about half a cubic kilometre. In the years to come the telescope will be expanded to measure one cubic kilometre (the full planned size). The project's cost (for the GVD-I phase) was about 2.5 billion Russian rubles (about 34 million $USD). == Results ==