History of the Institute of Nuclear Research of the Russian Academy of Sciences

The Institute for Nuclear Research of the Russian Academy of Sciences (INR RAS) was founded on December 24, 1970 by the decree of the Presidium of the USSR Academy of Sciences in accordance with the decision of the Council of Ministers of the USSR.

In December 2020, the Institute for Nuclear Research of the Russian Academy of Sciences (INR RAS) celebrated its 50th anniversary. The Institute for Nuclear Research of the Russian Academy of Sciences today is a major center of particle physics with a wide network of international cooperation projects. INR RAS is specialized in cosmology, neutrino physics, astrophysics, high energy physics, accelerator physics and technology, neutron research and nuclear medicine. A number of well-known unique scientific facilities operate at INR RAS, including the Complex of High-Current Linear Accelerator of Hydrogen Ions in Troitsk, the Baksan Neutrino Observatory (Elbrus region, Kabardino-Balkarian Republic), the Baikal Neutrino Telescope (Lake Baikal, Irkutsk Region) and the "Troitsk nu-mass experiment" (Troitsk, Moscow).

A decisive role in the creation of the Institute for Nuclear Research was played by Academician Moses Alexandrovich Markov together with outstanding Soviet physicists: Nobel Prize winner Academician Ilya Mikhailovich Frank and Academician Nikolai Nikolaevich Bogolyubov. Thanks to the influence of M.A. Markov, the institute formed two research areas: microcosm physics - elementary particle physics, and large-scale physics - the science of the origin and evolution of the Universe, cosmology. M.A. Markov's pioneer ideas formed the basis for the creation of modern unique facilities and the fundamental research program of the Institute.

Three nuclear laboratories of the Physical Institute of the USSR Academy of Sciences named after P.N.Lebedev became the basis for the creation of the Institute for Nuclear Research:

• Atomic Nucleus Laboratory, headed by Nobel Prize winner Academician I.M.Frank;
• Laboratory of Photonuclear Reactions, headed by L.E.Lazareva, which was founded by Academician V.I.Veksler;
• Neutrino Laboratory, widely known for the works of Academicians G.T.Zatsepin and A.E.Chudakov.

Over the years, INR RAS was headed by:
- Academician of the Russian Academy of Sciences Albert Nikiforovich Tavkhelidze, since the foundation of the Institute in 1970 to 1987
- Academician of the Russian Academy of Sciences Victor Anatolievich Matveev, from 1987 to 2014
- Corresponding Member of the Russian Academy of Sciences Leonid Vladimirovich Kravchuk, from 2014 to 2020
- Corresponding Member of the Russian Academy of Sciences Maxim Valentinovich Libanov, from 2020 to the present.

Since the foundation of INR RAS throughout its history, the main focus has been on the creation and development of unique research facilities and centers for collective use, among which are:

• I. The most powerful linear proton accelerator in the Euro-Asian region (Troitsk, Moscow), which provides fundamental and applied research in the field of nuclear and neutron physics, condensed matter, the development of technologies for the production of a wide range of radioisotopes, the operation of a radiation therapy complex and many other applications.
  
• II. The Baksan Neutrino Observatory (Neutrino settlement, Kabardino-Balkarian Republic) with a complex of large-scale underground neutrino telescopes and large-area ground facilities for studies in the field of solar neutrino physics, cosmic ray physics and neutrino astrophysics. The Baksan Gallium-Germanium Neutrino Telescope performed precision measurements of the rate of capture of solar neutrinos by gallium nuclei, which, together with the results of a number of other experiments with solar neutrinos, gave unambiguous evidence of the thermonuclear nature of the Sun's energy and led to the discovery of interconversions (oscillations) of neutrinos of various types. Starting from mid-2019, a new BEST (Baksan Experiment for Sterile Transition) experiment has been conducted. The purpose of the experiment is the study of neutrino oscillations at record short distances and the possible detection of neutrinos of a new type, the so-called sterile neutrino The Laboratory of Low-Background Studies has obtained the world's best limitations on the probability of double K-capture in the nuclei of 78Kr, 124Xe and double beta decay of a number of elements. The Carpet-3 experiment with the world's largest compact muon detector is aimed at achieving record sensitivity to diffuse gamma radiation with energies above 100 TeV.
  
• III. A unique Neutrino Telescope on Lake Baikal (Irkutsk region), created by the Institute for Nuclear Research of the Russian Academy of Sciences in collaboration with JINR which is part of the Global Neutrino Network (GNN) as the most important element of the network in the Northern Hemisphere. The Baikal-GVD neutrino telescope is designed to record and study ultra-high energy neutrino fluxes from astrophysical sources. The effective volume of the installation in registration of shower events from neutrinos is 0.35 cubic kilometers. Simultaneously with data collection, the telescope continues to grow to a volume of 1 cubic kilometer.
  
• IV. The "Troitsk-Nu Mass Facility" for measuring electron antineutrino mass in the beta decay of tritium. The limit on the neutrino mass obtained at the facility remained the best in the world for 15 years. This record was broken in 2019 at the KATRIN facility in Germany, with the participation of scientists from INR RAS. The design of the KATRIN facility is an enlarged model of the "Troitsk-nu-mass experiment", originally proposed by Academician V.M.Lobashev.

A number of innovative high-tech developments have been created at INR RAS. Technologies have been developed for the production of a wide range of radioactive isotopes for diagnostics and therapy in medicine and for technical purposes, including a Strontium-Rubidium Generator for PET.

A radiotherapy center is now under way and the first groups of patients have been treated. Innovative devices and methods for medical and technical applications have been developed, including radiation protection kits for the Russian Emergency Control Ministry, a research densitometer, and xenon anesthesia equipment for surgery.

The accelerator structure developed at INR RAS is used to build J-PARK accelerators in Japan and PITZ at the DESY location in Germany. The bunch shape monitor developed at INR RAS is installed at all leading international accelerator centers, including SSC, CERN, DESY, KEK, J-PARK, SNS, LANSCE, FRIB, GSI, ESS and JINR.

New experimental data were obtained on nuclear reactions involving protons and neutrons of medium energies, on photonuclear reactions, the spin structure of the proton was studied using an active polarized target, new effects were observed in collisions of relativistic nuclei, a new scientific branch, named "nuclear photonics", was initiated.

The results of theoretical research by scientists of the Institute in the field of high-energy physics, elementary particles and cosmology are widely known, including: the development of perturbation theory methods in quantum field theory, the study of the ground state (vacuum) in gauge theories, the development of methods for studying the dynamics of strong hadron interactions outside the framework of perturbation theory, the study of processes beyond the Standard Model of elementary particles, the creation of the first models of the world on a brane, the development of principles and the search for mechanisms for the formation of baryon asymmetry of the Universe, the study of the relationship of particle physics, astrophysics and cosmology, the construction of models of dark matter and dark energy.

These works received numerous awards. In 2020, Academician V.A.Rubakov was awarded the prestigious Hamburg Prize in Theoretical Physics for major advances in unraveling the mystery of the origin of the Universe. Two effects in particle astrophysics are named in honor of the scientists of INR RAS. The effect of high-energy cutoff of the spectrum of ultra-high-energy cosmic rays is named after Kenneth Greisen (USA), Academician G.T.Zatsepin and Corresponding Member of the Russian Academy of Sciences V.A.Kuzmin. The effect of neutrino oscillations in matter is named after S.P.Mikheev, A.Yu. Smirnov and Lincoln Wolfenstein (USA).

INR scientists cooperate with many leading laboratories, institutes and universities of the world, take an active part in a number of major international experiments at CERN (Switzerland), JINR (Russia), Germany, Japan, Italy, USA, China, France, Spain and other countries. The Institute conducts educational activities, has its own postgraduate school and basic departments at MIPT, MSU, MEPhI, KBSU and collaborates with other Russian universities.

The future of scientific research at INR RAS is closely connected with mega-science projects.

It is planned to complete the construction of the Baikal-GVD Neutrino Telescope with an effective volume of 1 cubic kilometer. Such a volume will make it possible to detect neutrinos of astrophysical origin with the same sensitivity as in the IceCube experiment in the Southern Hemisphere and will allow one to determine their origin.

A project has been prepared for the modernization of the Linear Proton Accelerator in Troitsk using superconducting resonators. The project will make it possible to achieve an energy of 1 GeV and a beam power of 1 MW. It is planned to build a large center for nuclear medicine on the basis of the Proton Linac.

A proposal to create the New Baksan Neutrino Telescope (NBNT) has been prepared. It is planned to use 10 kilotons of ultrapure liquid scintillator as the working substance of NBNT. This experiment will be able to detect neutrinos of the CNO cycle of thermonuclear reactions in the Sun. The sensitivity of the experiment will allow one of the existing models of the Sun to be confirmed.