Scientists Institute for Nuclear Research of the Russian Academy of Sciences (Moscow) and the Joint Institute for Nuclear Research (Dubna) said that with the assistance of a number of Russian research organizations participating in the collaboration of “Baikal”, deployed and put into operation a unique experimental facility – deep-water neutrino telescope multimegatonnogo scale “Dubna” on Lake Baikal. He became the first cluster created kubokilometrovogo scale neutrino telescope Baikal-GVD (Gigaton Volume Detector). Accommodation in Lake equipment is designed to study the natural flow of high-energy neutrinos.
Neutrinos passing through the thickness of the Earth may have a chance to interact in the water of Lake Baikal and produce a cascade of charged particles. And they are – light: the so-called Cherenkov light from charged particles. The light spread in the lake water and be registered optical telescope modules.
The cluster “Dubna” contains in its composition 192 optical modules, diving to a depth of up to 1300 meters. He became one of the largest in the world. The next stage of the project will be a consistent increase in the telescope through the deployment of new clusters.
Registration in Lake Baikal neutrino high energy allows us to understand the processes occurring in distant astrophysical sources, the origin of cosmic rays of the highest ever recorded energies open New properties of elementary particles and to learn a lot about the structure and evolution of the universe as a whole.
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Valery Rubakov, Academician, Chief Nuclear Physics of the Physical Sciences Division, RAS:
– The ensemble currently known elementary particles of neutrinos takes position as one of the lightest of its members and secured for itself in recent decades, the status of the greatest “intriguer.” The uniqueness of the particle as a carrier of information about the processes occurring in the universe, due to its ultra-low interaction with matter.
The natural flux of neutrinos carries a rich and unique in many respects, information about the world around us. The study of this flow in different energy ranges can give the key to understanding the early stages of evolution of the universe, the processes of formation of the chemical elements, the mechanism of evolution of massive stars and supernova explosions, shed light on the problem of the dark – invisible – matter, composition and internal structure of the Sun today in a fairly the remote past, and even deeper insight into the problem of the internal structure of one of the most difficult to study objects – planet Earth.
Victor Matveev, academician, director of the Joint Institute for Nuclear Research (Dubna):
– The idea of registration of elementary particles at large Cherenkov detectors in natural transparent media was first proposed in the early 60-ies outstanding Soviet scholar Moses Markov. At the suggestion of Academician Alexander Chudakov in the Soviet Union began to develop a deep-water detection method oriented towards the Lake Baikal as a testing ground for the deployment and location of future large-scale neutrino telescope. Selecting Baikal was due to the high transparency of fresh deep water, deep lake, the presence of ice, which allows for two winter months lead to a deep-sea equipment installation.
The date of commencement of the Baikal neutrino experiment can be considered as 1 October 1980, when in the Institute for Nuclear Research of the USSR (now the INR) has been established Laboratory for High Energy neutrino astrophysics led Gregory. Domogatskii, which later became the core of the Baikal collaboration, of which were at different stages of the Joint Institute for Nuclear Research (Dubna), Irkutsk State University, Moscow State University. MV University, research center DESY-Zeuthen (Germany), Nizhny Novgorod State Technical University, St. Petersburg State Marine Technical University and several other research organizations in Russia, Hungary, Germany, the Czech Republic and Slovakia. Currently, at the discussion stage – part of the Cracow Institute of Nuclear Physics (Poland).
From 1993 to 1998 the Baikal was deployed the world’s first deep-sea neutrino telescope NT200 containing 192 photodetector grouped into eight vertical garlands placed at a depth 1100–1200 m and covers 100 000 cubic meters of fresh water. Already from the set of experimental data in 1994 it was allocated first in the world of deep and under-ice events from neutrino experiments. It was implemented a broad program of research and received one of the most significant results for their time in search problems neutrinos from local sources, the diffuse neutrino flux obtained limitations on the flow of magnetic monopoles and muon flux from the decay of dark matter in the center of the Earth and the sun.
The idea of deep-registration of its ice modification, when instead of a natural pond photodetectors are immersed in a clear Antarctic ice, has led to the creation of the South Pole IceCube neutrino telescope of 1 cubic kilometer (panellists Collaboration – the US, Germany, Sweden) , which were first reported in 2010–2013 yy “Astrophysical” high-energy neutrinos, neutrinos ie born outside the solar system. Registration of these neutrinos, which marked the birth of neutrino astronomy, has put on the agenda the need to create neutrino telescopes near capacity in the Northern Hemisphere, in order to conduct a study of sources of high energy neutrinos across the celestial sphere. JINR, already has many years of experience in the Baikal neutrino project, agreed to consider the work of creating a large-scale neutrino telescope BAIKAL-GVD as one of its research priorities. “
Gregory Domogatskii, corresponding member of the Russian Academy of Sciences , coordinator of the Baikal neutrino project:
– Successful operation for over ten years neutrino telescope NT200 and the results of the analysis of the data it proved the effectiveness of the method of deep-sea neutrino detection in fresh water lake. Baikal. The next step was the development of a new generation of telescope project BAIKAL-GVD viewed with the volume of water mass is about 1 cubic kilometer.
During 2006–2010 yy They have been developed, manufactured and tested in natural conditions of all the samples of the basic elements and systems of the telescope Baikal-GVD. The telescope will have a modular structure made up of the independent functional units – clusters of vertical strings of optical modules. The modular structure will allow the telescope to conduct a set of experimental data in the early stages of deployment and installation offers the prospect of virtually unlimited capacity of its volume. The chosen structure of the telescope will also change its configuration as changes over time of scientific priorities.
In 2011, began the final stage of full-scale testing of complex components and systems of the telescope, which ended in 2015, the creation of deepwater installation “Dubna” – the first cluster neutrino telescope Baikal-GVD. The cluster includes a photodetector 192, placed garlands on 8 vertical length of 345 meters each, and is one of the two most powerful high-energy neutrino detectors in the Northern Hemisphere.
The next stage of the project will be the Baikal-GVD consistent increase in the telescope for through the deployment of new clusters. By 2020, it planned to create a unit consisting of 10-12 clusters, totaling about 0.5 cubic kilometers. That compares with a sensitive volume for the IceCube neutrino detection of high-energy astrophysical nature.
It is expected that the second phase of the telescope will contain 27 clusters with a total volume of about 1.5 cubic kilometers.
Christian Shpiring, head of the project Global Neutrino Network, last leader of the collaboration IceCube :
– An important step in creating an exciting neutrino telescope of new generation on the lake. Such a telescope will be a key future international setting Neutrino Observatory, which will include detectors at the South Pole, in the Mediterranean Sea and Lake Baikal. Collaboration Baikal was the founder of this technology in the 80s and 90s – conducted measurements of particles of neutrinos produced in the Earth’s atmosphere. Two decades later, in 2013 IceCube detector in the Antarctic has registered the first high-energy neutrinos, born far beyond the Earth and the solar system. This discovery, which has long been waiting for, accelerate the establishment of large projects such detectors in the Northern Hemisphere. With the commissioning of the cluster “Dubna” Baikal collaboration comes to leading positions in these studies.
IceCube detector is only slightly opened the veil of high energy neutrinos in the universe. In the future, the project partners Global Neutrino Network will make a complete map of this new space territory. We are waiting for the great scientific discoveries on the lake!
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Collaboration “Baikal” includes today – the Institute for Nuclear Research (Moscow), Joint Institute for Nuclear Research (Dubna), Irkutsk State University, Moscow State University. MV Lomonosov Moscow State University, Nizhny Novgorod State Technical University, St. Petersburg State Marine Technical University, the company Evologic (Germany), Institute of Nuclear Physics (Rez) and the Institute of Experimental and Applied Physics (University of Prague, Czech Republic), Bratislava University (Slovakia).
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