The first scientific research in the field of physical science in the system of the Academy of Sciences of the Republic of Tajikistan was associated with the organization in 1957, at the initiative of the President of the Academy of Sciences of Tajikistan, academician of the Academy of Sciences of the Tajik SSR and Uzbek Academy of Sciences Sulton Umarovich Umarov of the Department of Physics and Mathematics. At the same time, intensive and targeted training of scientific personnel in the field of physics begins – many young specialists with an indefatigable thirst for knowledge, who were attracted by the unknown world of searches and discoveries, were sent to leading scientific centers of the USSR Academy of Sciences, the academies of sciences of Belarus, Azerbaijan, Uzbekistan and other fraternal republics.
The first research works of the Department of Physics and Mathematics was devoted to the study of the complex physical, physicochemical and structural properties of binary and complex semiconductor compounds, the interaction of negative ions with the surface of metals, the development of methods for increasing the sensitivity of emission spectral analysis, and some problems of nuclear physics. On June 1, 1964, the Physics and Technology Institute was founded on the basis of the existing laboratories of the Department of Physics and Mathematics, within the walls of which the above-mentioned problems of physical science were solved, and it was rightly named after its organizer – Academician Sulton Umarovich Umarov, a man of exceptional natural talents. Physicists with special pride and a sense of gratitude recall today the name of this remarkable person, an encyclopedically erudite talented scientist, one of the first Central Asian theoretical physicists, an outstanding scientist and statesman.
It is under the leadership of Academician S.U.Umarov in the Department of Physics and Mathematics created laboratories of nuclear physics, semiconductor physics, strength physics, optics and spectroscopy, which formed the backbone of the emerging Physicotechnical Institute, identified priority areas for the development of physical science in Tajikistan.
The minutes of the meeting of the Board of the State Committee for the Coordination of Scientific Research of the USSR dated April 11, 1964 No. 27 “On streamlining the network of scientific institutions of the Tajik SSR Academy of Sciences” recorded: “Accept the proposal of the Council of Ministers of the Tajik SSR and the Presidium of the USSR Academy of Sciences on the organization “at the Academy of Sciences of the Tajik SSR Physical-Technical Institute on the basis of the Department of Physics and Mathematics.” Behind the dry lines of the extract from the protocol, one can feel the enormous energy of Academician S.U. Umarov, his gift and the ability to convince high authorities of the need to create new institutions in the Academy of Sciences of Tajikistan, despite the lack of personnel, insufficient material and technical equipment of the laboratories.
In the Decree of the Central Committee of the Communist Party of Tajikistan and the Council of Ministers of the Tajik SSR dated May 29, 1964, No. 228, it was noted: «Considering the great achievements of Academician S.U. Umarov in the field of the development of science and physical research in the republic and in order to perpetuate his memory, to assign a physical technical institute of the Academy of Sciences of the Tajik SSR named after Academician S.U. Umarov to continue to call as: S.U.Umarov Physical – Technical Institute of the Academy of Sciences of the Republic of Tajikistan».
The creation of the S.U.Umarov Physical – Technical Institute was a big event in the life of the Academy of Sciences of the Republic of Tajikistan. The foundation was laid for the further planned development of physical and mathematical research in the republic, the solution of important national economic problems, the development and implementation of new technologies in the country’s industry. The institute is developing research in the field of fundamental and applied problems of nuclear physics, solid state physics, and semiconductors.
At the origins of the formation and development of physical science in the Republic of Tajikistan were doctor of physical and mathematical sciences, professor, Honored Scientist of the Tajik SSR, academician Akobir Adhamovich Adhamov – the first director of the institute, who headed the Physicotechnical Institute until 1991, doctors of physical and mathematical sciences, professors Latif Sharifovich Khodzhaev and Bakhrullo Narzullaev, candidate of physical and mathematical sciences N.M. Khashimov.
Under the direct supervision of academician A.A.Adkhamov, all the main areas of scientific research developed at the institute were formed. Academician A.A.Adkhamov organized and supervised the work of the Department of Theoretical Physics and the Laboratory of Physical Acoustics. Under his leadership, laboratories of dielectric materials, quantum electronics, cryogenic technology, and a laboratory of solar technology were organized. He was the head of research topics in theoretical physics, problems of physical acoustics and physics of ferroelectric materials.
Academician A.A. Adkhamov was a major expert in the field of theoretical physics, the main directions of his research lay in the field of molecular-kinetic theory of gases and liquids, molecular acoustics, and theory of phase transitions. He developed the kinetic theory of nonequilibrium processes in liquids, including the propagation of ultrasonic waves in liquids, the molecular theory of the viscoelastic properties of liquids, and the theory of resonant absorption of ultrasound in condensed matter. He proposed a kinetic theory of processes and fluctuation phenomena in liquids near a critical point, studied the features of the thermophysical, dynamic, and optical properties of defective crystals. These fundamental research works in the field of the statistical theory of condensed matter and molecular acoustics were the basis for the development of a number of areas of theoretical research in the school of theorists created by him. Academician S. Odinaev, corresponding member T.Kh.Salikhov, professors M.I.Salakhutdinov, A.Asoev, V.I.Lebedev, A.Ashurov, candidates of physical and mathematical sciences, associate professors A.Abdurasulov, H.Nasrulloev and a number of other scientists who contributed to the development of physical science in our country belongs to the group of talented theoretical physicists of the school of academician A.A.Adkhamov.
Academician A.A.Adkhamov was one of the major organizers of science in Tajikistan. Under his leadership, the Institute of Physics and Technology has turned into a large center for fundamental physical research, equipped with modern instruments and equipment, conducting comprehensive physical research on various problems of modern physics and technology. Under his leadership, the institute carried out extensive work on introducing the achievements of scientific and technical thought into the national economy and became a center for the training of qualified specialists for various industries of Tajikistan.
With the support and parting words of academician S.U.Umarov, highly qualified personnel were trained – academician R.M.Marupov, corresponding member I.I.Ismoilov, professors B.S.Umarov, Sh.S.Mazitov, Sh.M.Mavlonov, Kh.M.Kurbanov, M.A.Sultanov. The next generation of physicists such as academician S. Odinaev, academician Kh.M.Akhmedov, corresponding member. T.Kh.Salikhov, U.Madvaliev, professors M.I. Salakhutdinov, S.Sh.Akhmedov, F.Normurodov; Doctors of physical and mathematical sciences: N.Mukhtorov, S.F.Abdullaev, N.N.Shklyar, Yu.M.Shukrinov; Doctor of Chemistry T. Shukurov, Candidates of Physical and Mathematical Sciences I.B.Bobodzhonov, A.A.Dzhuraev, S.N.Sakiev, A.Kholov, R.A.Karieva, K.Kabutov, I.Rakhimov, B.Nazarov, V.Salimov, Sh.Sh.Azimov, M.N.Tseitlin, V.M.Nikolaev and many others, made a significant contribution to the development of the institute with its scientific research and the results obtained.
For 15 years after the creation of the institute, by 1979, the following scientific departments were organized and worked in the structure of the institute:
– The Laboratory of Nuclear Physics, established in 1962, is engaged in the development of applied problems of nuclear physics, studies of the interaction of cosmic particles with the nuclei of various elements at high and ultrahigh energies (Pamir experiment);
– The Laboratory of Semiconductor Physics, established in 1962, was engaged in the study of kinetic phenomena in semiconductors;
– The Laboratory of Strength Physics, established in 1962, was engaged in research in the field of physics of metal strength;
– The Laboratory of Optics and Spectroscopy, established in 1964, conducts research on the molecular spectroscopy of substances;
– The Activation Analysis Laboratory, established in 1966, develops the problems of applied nuclear physics and nuclear physics methods for studying the elemental composition and structure of substances for research in related fields of science and the national economy;
– The sector of theoretical physics, created in 1967, develops the molecular-kinetic theory of condensed systems, irreversible processes in condensed matter, phase transitions and critical phenomena, field-theoretical methods for studying quantum systems;
– The ultrasound laboratory, created in 1967, developed the problems of molecular acoustics, the acoustic properties of molecular and liquid crystals, and also developed non-destructive testing methods for the needs of the national economy;
– Laboratory of X-ray analysis, created in 1968, is engaged in the cultivation of new crystals and the study of their structure;
– The Laboratory of Quantum Electronics, established in 1971, develops the problems of obtaining and using semiconductor laser radiation;
– A Cryogenic Laboratory, established in 1972, studies the physical properties of conductors at low temperatures, and is currently developing the development of cryo-magnetotherapy tools for medical needs; – The Laboratory of Optoacoustics, established in 1976, operates in the field of solid state spectroscopy and Raman scattering.
In the next 15 years, by 1994, the Institute had 11 laboratories, 2 Departments and 4 groups, which conducted research in six main areas, covering 17 topics.
From 1991 to 1999, the institute was headed by a well-known scientist in the field of spectroscopy of macromolecular compounds, Doctor of Technical Sciences, Professor, Honored Scientist of the Republic of Tajikistan, Laureate of the State Prize of the Republic of Tajikistan named after Abouali ibn Sino in the field of science and technology, academician Rakhim Marupov.
The highly respected President of the Republic of Uzbekistan Shavkat Miromonovich Mirziyoyev on August 31 (2018), on the eve of the celebration of Independence Day of Uzbekistan, presented state awards to a group of state and public figures of Tajikistan. Including academician Rakhim Marupov – awarded the Order “Dustlik” (Friendship).
Academician R. Marupov developed special methods that made it possible for the first time to systematize spectroscopic features and reveal the subtle structural features of cotton fibers of various origins, fibers of healthy and wilt-affected plants. The molecular structure features of cotton cellulose during its biosynthesis, cotton and flax fibers, cellulose nitrates have been investigated, and the laws of molecular dynamics, the dynamics of the EPR spectra and their correlation with physical and mechanical properties have been established.
The Presidium of the Academy of Sciences of the Republic of Tajikistan, on the basis of a reference and the conclusion of a committee on the evaluation of the institute’s activities for 1991-1995, instructed the institute’s leadership to combine related laboratories and enlarge themes, linking them with the solution of problems aimed at developing the national economy of the republic. In February 1996, the Scientific Council of the Institute approved the new structure of the Institute, which was approved by the Department of Physical, Mathematical, Chemical and Geological Sciences. The number of scientific departments was reduced from 15 to 9. Simultaneously with the reorganization of the structure of the institute, an enlargement of topics was made. If in 1995 studies were conducted on 17 topics of the R&D plan of the Academy of Sciences of the Republic of Tajikistan funded from the state budget, in 1996 the number of topics was reduced to 7.
From 1999 to 2001, the Institute was headed by Doctor of Physics and Mathematics, Professor, Academician, Science and Technology Worker of Tajikistan Saidmukhamad Odinaev, a major specialist in the field of molecular kinetic theory of liquids. He developed the theory of structural relaxation of classical liquids, its applications in the study of electrolytes, magnetic fluids and other types of classical liquids. Academician S. Odinaev made a great contribution to the training of scientific personnel of the Republic of Tajikistan, a number of doctoral and candidate dissertations were defended under his leadership.
Academician S.Odinaev made a great contribution to the development of higher education in the Republic of Tajikistan, later heading the Tajik Technical University named after Academician M.S. Asimov and Tajik National University are the main forges of the republic’s cadres in the field of exact, natural and technical sciences. Thanks to his activities, the institute’s connection with higher educational institutions of the republic has significantly strengthened, and a positive trend has been noted in the influx of young specialists into academic science. As Vice President of the Academy of Sciences (until 2017), academician S.Odinaev did a great job of organizing the implementation of science and technology in industrial enterprises in Dushanbe, showing great concern for the urgent needs of the institutes of the Department of Physical, Mathematical, Chemical, Geological and Technical Sciences.
In 2001 – 2005, the institute was headed by the candidate of physical and mathematical sciences, associate professor Anvar Abdurasulovich Abdurasulov, the successor of the school of academician A.A.Adkhamov and academician S.Odinaev, a well-known specialist in the field of the molecular-kinetic theory of asymmetric liquids, electrolytes and liquid crystals. A.A.Abdurasulov made a great contribution to the development of the Institute’s relations with the International Science and Technology Center, the active inclusion of the Institute’s employees in international scientific and technical cooperation with the countries of the European Union, the USA and Canada. As rector of the Tajik Technical University named after academician M.S.Osimi (until 2013) A.A.Abdurasulov in every possible way contributed to strengthening the ties between academic and university science, attracting youth to fundamental and applied science.
From 2006 to 2017, the institute was headed by Khikmat Khalimovich Muminov, doctor of physical and mathematical sciences, professor, academician of the Academy of Sciences of the Republic of Tajikistan, a well-known specialist in the field of nonlinear mathematical physics and the theory of condensed matter. He developed the mathematical apparatus of generalized coherent states for higher spin values, which allows one to obtain an adequate semiclassical description of quantum spin systems taking into account the excitation of multipole fields. On this basis, a series of nonlinear evolution equations has been obtained that describe the dynamics of magnetization taking into account multipole fields in ferro- and antiferromagnets with spins 1 and 3/2, not reducible to the well-known Landau-Lifshitz equation. The theory of the geometric Berry phase is constructed for higher spin values, on the basis of which the theory of tunneling transitions in magnetic nanomolecules is developed. New dynamic and topological solutions (in one- and two-dimensional) of a vector nonlinear sigma model of field theory are obtained and investigated.
Currently, the director of the institute is the candidate of physical and mathematical sciences Farkhod Shokir.
The Institute includes the following divisions: the International Center for Nuclear Physics Research, the Center for the Study and Use of Renewable Energy Sources (established in 2008), the Department of Nanomaterials and Nanotechnologies (created in 2008), structurally covering 4 divisions:
- sector of theoretical physics,
- laboratory of crystal physics,
- laboratory of physical acoustics,
- laboratory of low temperature and superconductivity physics
Further, the structure of the institute includes:
- laboratory of molecular spectroscopy,
- atmospheric physics laboratories,
- laboratory of quantum electronics,
- informatization department (since 2019),
- computing cluster (since 2019).
The research work carried out on 6 topics in 11 departments of the institute covers the following main areas:
- nuclear physics,
- theoretical physics,
- condensed matter physics,
- optics, quantum electronics,
- physical and technical problems of energy,
- atmospheric physics,
- the use of physical research methods in medicine,
which solves the following problems:
- nuclear physical research methods,
- cosmic rays and ultrahigh-energy physics,
- physics of semiconductors,
- the formation and structure of crystals,
- physics of ferroelectrics and dielectrics,
- physics of condensed matter at low temperatures,
- coherent nonlinear optics (quantum electronics),
- the study of physical processes in the atmosphere,
- renewable energy sources.
In the direction of Nuclear Physics, problems of nuclear-physical research methods are being solved, and research is being carried out in the field of cosmic ray physics and ultrahigh energies.
It is appropriate to note here the major task that the institute faces – the restoration and commissioning of the Argus reactor, which is being mothballed. With the commissioning of the Argus reactor, the areas of neutron activation and neutron diffraction analysis will develop, and production of radiopharmaceuticals for the needs of nuclear medicine will be launched.
Cosmic ray research began in the Department of Physics and Mathematics with the study of parity nonconservation during the capture of cosmic ray muons by various nuclei of matter in order to study the asymmetry of neutron emission depending on the spin of the nucleus. The studies were based on the results obtained at a height of 3860 m above sea level in the Murgab district of the Gorno-Badakhshan Autonomous Region.
In 1971, on the initiative of the Physics Institute of the USSR Academy of Sciences (Lebedev Physical Sciences Institute) in the Pamir in the Ak-Arkhar tract at an altitude of 4360 m above sea level, joint research began with scientists of our institute to study the interaction of elementary particles and nucleons with nucleons and nuclei at energies above 1012 eV (Pamir experiment). During the experiment, an installation of an X-ray emulsion chamber with an area of 1000 m2 was assembled. In fulfilling the tasks of the Pamir experiment, the Physical-technical Institute named after S.V. Starodubtsev of AN of the Uz. SSR, Institute for Nuclear Research of the USSR Academy of Sciences, Nuclear Physics Research Institute named after D.V.Skobeltsin of the Moscow State University, Institute of High Energy Physics of the Kazakh Academy of Sciences. SSR, Institute of Physics, Academy of Sciences of Georgia. SSR. In 1987, in Paris, at the 17th International Cosmic Ray Conference, an agreement was signed on the co-construction of the Pamir-Chakaltai super cooperation, which united the efforts of physicists from eight countries: Russia, Japan, Poland, Brazil, Bolivia, Georgia, Uzbekistan and Tajikistan.
In the Pamir experiment, a number of unique and rare phenomena were observed, such as the “Sitora” superfamily, formed by a particle with energy of the order of 1017 EV. The interaction energy of particles of primary cosmic radiation of the “Tajikistan” superfamily was 1018 EV – this is the largest interaction energy of particles from all recorded in the world practice using large X-ray emulsion cameras.
The Pamir experiment, launched in 1971, resulted in an Agreement between the Government of the Republic of Tajikistan and the Government of the Russian Federation on the establishment and operation of the Pamir-Chakaltaya International Research Center (IRC-PCh), signed in August 2008 for conducting joint nuclear and astro-physical studies of ultrahigh-energy cosmic rays.
In July-August 2009, after a long break, the IRC-PCh organized the Pamir expedition of 2009. The main purpose of the expedition was to restore the forces of Russian and Tajik expedition members, as well as a group of volunteers from Kyrgyzstan, Kazakhstan, Ukraine and France, industrial and residential premises and buildings, as well as the infrastructure of the scientific training ground located at an altitude of 4400 in the tract Ak-Arkhar of the Murghab district of Gorno-Badakhshan Autonomous Region (GBAR) of the Republic of Tajikistan. This allowed the resumption of experimental studies of ultrahigh-energy cosmic rays at mountain heights according to the scientific program of the IRC within the framework of wide international cooperation. During this expedition, an exposition of a two-tier deep X-ray emulsion chamber with an air gap of 2.5 m and an area of 36 sq.m was collected and started.
The main scientific goal of the experiment is to study the nuclear-active penetrating component of cosmic rays at mountain heights and to establish its nature, possibly associated with charmed particles and the rapid growth of their share in the total inelastic cross section with increasing energy, or with the presence of their composition of particles of strange quark matter – stranglets.
September 29-30, 2010 in Dushanbe and the village of Chechekty, the International Scientific Conference “Prospects for interdisciplinary alpine research of astro-cosmic factors affecting natural systems and global natural processes” was held. The conference was held by the Academy of Sciences of the Republic of Tajikistan with the support of the Interstate Fund for Humanitarian Cooperation of the CIS countries. On April 21-22, 2011, in Dushanbe (Republic of Tajikistan), the International Scientific Seminar “Actual Tasks and First Results of the Pamir-Chakaltaya International Research Center” ”was held. The successfully completed seminar gave an additional impetus to the cooperation of scientists from the CIS countries within the framework of the Pamir-Chakaltaya International Research Center. It allowed me to outline the most promising directions for the development of cosmic ray research at mountain heights in the light of the results that have been achieved recently, both in the field of cosmic ray physics and high energy physics, which is developing intensively thanks to the Large Hadron Collider launched at CERN. In particular, the seminar discussed the problems of exchange and comparison of research results of space physicists and physicists working on accelerators, as well as ways to solve them, which mutually increase the efficiency of searching for new phenomena and effects that indicate the emergence of “new” physics ultra-high energies.
In the process of radioecological research in the direction of “Nuclear Physics”, laboratory scientists created and tested a facility for the detection and study of samples of radioactive fallout as part of an air aerosol. The facility is designed to search for anomalous loss zones of the cosmogenic Be-7 radioisotope and to explain one of the possible migration routes of the Be-7 isotope to the surface of soil, vegetation, and water through vertical airflows from the upper atmosphere and tropopause.
The development of new methods for studying the content of radon in air, soil, water, and precipitation, as well as methods for analyzing the radiation situation in mountainous areas, was continued. In the process of performing work based on nuclear-physical methods, a study of the mountain regions of Tajikistan on the presence of technogenic pollution was justified.
The distribution of uranium and thorium in soil samples of the Varzob River is obtained. An increase in the concentration of these elements in the gorge of the Ojug River, the village of Varzob, was established. For the first time, the modern relief of the Kairakum reservoir was registered and determined by the method of ultrasonic location. The results of these studies are important for solving environmental and other national economic problems.
The simulation of the efficiency of gadolinium converters for neutron radiation detectors is carried out. Calculations were carried out to elucidate the effect of nanoscale layers of gadolinium-based neutron converters on the overall efficiency of thermal neutron detection. By taking into account the contribution of low-energy Auger electrons, the overall efficiency of the converters increases. For converters from the gadolinium-157 isotope, the overall efficiency increases by more than 10%. It is shown that when calculating the efficiency of converters based on the gadolinium-157 isotope, it is necessary to take into account nanoscale layers, the minimum sampling step should be no more than 10 nanometers. The results obtained are in good agreement with experimental data.
The direction “Condensed Matter Physics” covers a wide range of studies related to solving fundamental problems of studying the state and structure of matter, its properties and parameters, depending on the action of various factors. The solution to these problems can serve as the basis for developing a technology for the production of promising new materials, including composite materials based on semiconductor compounds with predetermined properties, new methods of analysis and control of materials in the process of their preparation and subsequent alloying with impurities that qualitatively improve their physicochemical properties, giving the ability to create devices based on them. Studies are being conducted to obtain films and heterostructures based on organic semiconductors.
The Institute has developed a technology for growing crystals of triple lithium-bismuth borates under conditions of low temperature gradients. Crystallization of triple borates revealed defects associated with crystal growth mechanisms. The study of the nature and causes of such defects makes it possible to determine both the morphology of the crystallization front and its stability, as well as the establishment of small-angle boundaries and blocks associated with a change in stoichiometry of the melt and the formation of gas inclusions. For the first time, experiments were carried out on the production of triple borates by mechanosynthesis, a completely new approach to the technology for producing such compounds.
Research in this area is carried out mainly by the Department of Nanomaterials and Nanotechnology, which was created in 2008 as part of four previously existing divisions: the theoretical physics sector, the laboratory of crystal physics, physical acoustics (since 2008) and the laboratory of low temperature and superconductivity physics (since 2019). The department is tasked with continuing the earlier research in the field of theory, developing technologies for creating and experimental and theoretical studies of new materials, crystals, which have useful physical properties, and are widely used in the creation of high-tech devices (lasers, microelectronics, detectors of various types of radiation, etc).
In connection with the rapid development of nanotechnology, the department was tasked with the development of nanotechnology, such as creating new materials (single crystals and nanomaterials) with useful physical properties, which is of great and lasting importance for the development of engineering and technology, as well as research tasks properties and the creation of new nanomaterials, bulk nanostructured crystals, nanocoatings and other materials that can be widely used in various fields of the national economy. Modern technology requires crystalline materials with various physical properties. The development of many branches of science and technology is associated with achievements in the field of obtaining new materials, with the help of which not only the parameters of existing devices can be improved, but also new ones can be created.
Comprehensive studies of the class of compounds of double molybdates and tungstates containing monovalent and divalent cations allowed us to predict and then confirm physical properties for a number of structural types such useful properties as laser, acousto-optical, piezoelectric and ferroelectric, ferroelastic, electrolytic, luminescent, pyroelectric and other Neodymium-activated crystals of low-temperature modification of potassium-yttrium tungstate and other isostructural compounds possess unique spectral-generating properties, and have found application in special instrumentation. A family of new piezoelectric and ferroelectric crystals with a cristobalite-like structure – cesium-lithium molybdate, cesium-lithium tungstate and other isostructural compounds with effective electromechanical and other properties, has been developed and found in the Crystal Physics Laboratory of Nanotechnology and Nanomaterials Department. Authors’ certificates were obtained on methods for growing single crystals: CsLiMoO4, CsLiWO4, NaBi(WO4)2, LiBi(MoO4)2, as well as with the addition of neodymium impurities. New crystals based on rare-earth oxides and bismuth oxide were obtained: Pr3Bi5O12, Er3Bi5O12, Yb3Bi5O12, Lu3Bi5O12. A technology for producing single crystals of a high degree of perfection is being developed.
In the laboratory of physical acoustics, unique methods for studying physical properties, phase transitions, and physicochemical processes at the solid-liquid interface have been developed and introduced, both by methods of active acoustics and by methods of acoustic emission.
In the sector of theoretical physics, for several years, studies have been carried out on the physical (acoustic, piezoelectric, optical, magneto and ferroelastic) properties of condensed matter caused by the excitation and dynamics of quasiparticles (excitons, phonons, magnons, etc.) and their complexes (polarons, solitons, coupled magneto-elastic solitons, etc.). To this end, a method of generalized coherent states has been developed that takes into account group-theoretical properties and symmetries of the initial Hamiltonians, and the Hamiltonians and semiclassical equations of motion are obtained by functional integral methods. A generalization of the known geometric Berry phase for generalized coherent states built on the SU (2S + 1) group is obtained, which allows a detailed analysis of the tunneling effects in magnetic nanomaterials (in magnetic nanostructures such as Fe8 and Mn12) to take into account the reduction in the length of the classical spin due to excitation of multipole fields. The method of generalized coherent states is successfully used in studying structural phase transitions in crystals (spin Peierls and electronic Peierls phase transitions), studying the propagation of nonlinear magnetosonic waves in magnetic materials, and studying the problem of controlling the properties of nanostructures. Widely used are computer simulation methods based on the molecular dynamics method, Monte Carlo method, and density function theory.
Computer numerical simulation methods are used to study spatially one- and two-dimensional nonlinear evolution equations describing nonlinear excitations of various nature in condensed matter (Heisenberg anti- and ferromagnets, graphene, hadron matter in high and ultrahigh-energy physics). In particular, the stability and dynamics of interactions of two-dimensional dynamic topological solitons in a vector nonlinear sigma model of field theory in the isotropic and anisotropic cases were studied. Numerical simulation methods show the stability of this type of soliton at various values of the topological charge (Hopf index). Long-range models for the evolution of the dynamics of the elastic interaction of two-dimensional topological solitons are obtained. Possible decay channels for collisions of two-dimensional topological solitons are demonstrated. New bionic (breather) solutions of the vector nonlinear sigma model are obtained both in the one- and two-dimensional cases, possessing both breather dynamics and dynamics of rotation in isospin space, and their existence and stability are determined. These results are of interest from the point of view of the development of nonperturbative models of field theory. The properties of the T-symmetry processes of a supersymmetric (2 + 1) -dimensional nonlinear sigma model are investigated. At the first stage, interaction models of topological vortices were developed, where, depending on the dynamic parameters, processes of their decay into localized perturbations and phased annihilation are observed. Models of phased annihilation of topological vortices during their interaction with 180-degree domain walls are also considered. Based on the obtained models, initial conditions have been developed for the numerical simulation of interaction processes in reverse time. Models are obtained that describe the complete restoration of the initial topological field of interacting solitons upon combining localized perturbations and radiation waves. Also, models were obtained that describe the processes of formation of topological vortices in the plane of the domain wall and their subsequent emission. Thus, the T-invariance property of the studied field-theoretical model is confirmed.
The known nanostructured solar elements based on silicon carbide are compared, and a number of features of the sol-gel process for the synthesis of silicon carbide nanopowders are investigated. On this basis, an effective and low-cost technology for producing silicon carbide nanopowders by the sol-gel method has been developed. A study was made of nanopowder samples of silicon carbide in the production process, as well as after their annealing at various temperatures in order to obtain nanocrystals of various sizes and determine their most optimal sizes. The physical properties of the obtained samples were studied using modern methods and methods (scanning and power electron microscopy, X-ray phase analysis and infrared Fourier spectroscopy).
The analysis of the physical principles of creating nanostructured solar cells and the principles of their work is carried out. Dye-sensitized solar cells without light diffusers, as well as with nanostructured diffusers based on titanium dioxide and titanium dioxide / silicon carbide, were created and their effectiveness was evaluated.
A study of the effectiveness of single-junction and multilayer tandem solar cells is carried out. A numerical model has been developed using the AMPS-1D one-dimensional microelectronic and photonic structure analysis program for the analysis of hydrogen cells based on hydrogenated silicon, cadmium telluride and copper-indium-gallium dyslenide, which allowed us to formulate the design for the optimal design of new multilayer tandem solar cells providing the highest efficiency of the cell.
A single-junction solar cell based on amorphous hydrogenated silicon was numerically analyzed, between the p-type (a-SiC: H) and n-type (a-Si: H) layers, which is a doped i-layer used as an intermediate absorbing layer (a-Si: H). It was found that after optimizing the element parameters, the highest efficiency of 19.62% is achieved with an i-layer thickness of 500 nm. The developed new structure of a tandem multilayer solar cell based on a-SiC: H / a-Si: H was optimized and numerical simulation showed that its highest efficiency of 22.6% is achieved with an intermediate i-layer thickness of 270 nm.
Numerical simulation methods have shown that the highest efficiency of a single junction solar cell based on cadmium sulfide and cadmium telluride CdS / CdTe, equal to 18.3%, is achieved with a CdTe layer thickness of 1000 nm and a CdS layer thickness of 60 nm. Based on the simulation of a single-junction solar cell, the optimal structure of the tandem multilayer solar cell CdS / CdTe was developed, and numerical simulation showed that its highest efficiency of 31.8% can be obtained with a CdS p-layer thickness of 50 nm and an n-layer thickness CdS equal to 200 nm, while maintaining a fixed thickness of the n-layer CdTe at 3000 nm and the p-layer CdTe equal to 1000 nm.
A numerical study of single-junction solar cells based on cadmium sulfide and copper-indium-gallium dislenide CdS / CIGS was carried out and it was shown that the highest efficiency of 17.3% is achieved with a CIGS layer thickness of 200 nm. Using the results of studying single-junction solar cells, a design was developed and the structure of a new tandem multilayer solar cell based on CdS / CIGS was optimized. Numerical simulation methods showed that the highest efficiency of this element, equal to 48.3%, can be obtained with a CIGS p-layer thickness of 600 nm.
A detailed study of the phase dynamics and current – voltage characteristics in a system of coupled Josephson junctions is carried out. The hysteresis region of the I – V characteristic of a system of coupled Josephson junctions of the dependence of the superconducting, quasiparticle, diffusion currents, and bias current on the total current through the system was studied for the first time. These studies showed the important role of the diffusion current in the formation of the current – voltage characteristics of the system and made it possible to obtain qualitative agreement with the experimental results. The effect of diffusion current on the branching process of the current – voltage characteristic and the magnitude of the return current are shown. It was shown in the works that the presence of only a capacitive coupling between Josephson junctions does not explain the hysteretic behavior of internal Josephson junctions in high-temperature superconductors. The experimentally observed overestimated value of the return current on the I – V characteristic compared with estimates based on the model of unconnected junctions finds its explanation in the framework of the model of capacitive coupling with diffusion current.
In Tajik medicine, new developments have gained widespread use along with traditional methods. In this direction, the cryophysics laboratory of the S.U.Umarov Physical – Technical Institute of the Academy of Sciences of the Republic of Tajikistan (PhTI AS RT) made a significant contribution:
- cryotherapy using liquid nitrogen;
- early diagnosis using molecular spectroscopy methods;
- magnetic and laser therapy.
Cryotherapy with the use of liquid nitrogen in our country became possible due to the fact that in 2014 the liquid nitrogen station of the S.U.Umarov Physical – Technical Institute of the Academy of Sciences of the Republic of Tajikistan was restored. As you know, liquid nitrogen is widely used in various fields of medicine: gynecology, gastroenterology, cosmetology, oncology, as well as in agriculture. The S.U.Umarov Physical – Technical Institute of the Academy of Sciences of the Republic of Tajikistan produces liquid nitrogen, which is widely used not only in scientific research of the Academy of Sciences, research laboratories of higher educational institutions, ministries, departments, as well as in the industry of the republic.
At the S.U.Umarov Physical – Technical Institute of the Academy of Sciences of the Republic of Tajikistan, together with the Scientific Research Gastroenterological Institute of the Ministry of Health of Tajikistan, an apparatus has been invented with which you can use liquid nitrogen to destroy invisible cancer cells in place. Just during 2016, 50 patients with tuberculosis and cirrhosis of the liver, other diseases underwent surgery using the new technology (by MD, professor S.Akhmedov), and people started recovering. To date, more than 230 successful cryosurgical operations have been performed. Prior to this, this technology was used in the oncology center of Moscow, and it was also used in the Netherlands, Italy and Japan. For Tajikistan, this treatment was not available.
In the direction of “Quantum Electronics”, research is being conducted on the development of semiconductor injection lasers, on laser therapy and laser biostimulation, on the study of protein fractions isolated from healthy and sick organisms by IR spectroscopy, as well as on the study of semiconductor emitters and solar energy converters based on compounds AIII BV, which can be found and are already widely used in medicine. A number of proposals of our scientists are patented jointly with physicians.
Important results were obtained in the field of physical and technical acoustics, in particular, a photoacoustic method for non-destructive testing of solids and biological objects was developed.
A technology has been developed to obtain a porous structure on the surface of indium phosphide plates during electrochemical etching, which allows one to obtain nanoporous films. The technology for producing such structures brings the method of electrochemical etching, as the most simple and least expensive method, to the number of practical nanotechnology methods in semiconductor microelectronics. The direction includes the study of r-p and heterojunctions, the creation of multilayer and porous semiconductor structures with the aim of creating heterolasers and converters of solar energy.
Studies in the field of “Physical and Technical Problems of Energy” are devoted to the development of non-traditional renewable energy sources, an important advantage of which is inexhaustibility and environmental cleanliness. The main problems studied here are related to the development of elements, devices and principles for the use of renewable energy sources (solar plants for converting solar energy into heat and electricity, mini hydroelectric power stations, biogasification plants, wind power plants, etc.), assessment of the potential of renewable energy sources in Tajikistan and economic the effectiveness of their use.
According to the State “Target comprehensive program for the widespread use of renewable energy sources, such as energy of small rivers, the sun, wind, biomass, underground energy for 2007-2015,” the Center for the Study and Research of Renewable Energy Sources was the lead contractor and coordinator research work. Together with the Aga Khan Foundation MSDSP (with the financial support of the European Union), the TFCIS-ILCA-2009 and 2010 project “Use of renewable energy in the mountains” was completed. Deadlines for 2009-2010. Projects were implemented in 3 districts: Muminabad, Shuroabad and Khovaling.
The direction “Atmospheric Physics” includes studying the state of the atmosphere, parameters affecting the state of the climate and the ozone layer, as well as studying the processes of formation of atmospheric aerosol as a result of dust storms and monitoring the state of technogenic pollution of the atmosphere: The total ozone content in the vertical column of the atmosphere is regularly measured in different periods of the year. Investigations of dust aerosol samples by photoacoustic spectroscopy in the ultraviolet and visible spectral regions and comparison of these results with the data obtained by IR spectroscopy and diffuse reflection methods made it possible to establish the identity of the nature of terrestrial dust aerosols and Martian dust. The results of these studies are essential for solving the problems of predicting climate and weather, as well as elucidating the role of aerosols in their change.
PhTI AS RT for several years collaborates with the Institute of tropospheric research. Leibniz of Germany (TROPOS). On June 26, 2019, in Dushanbe, the Sixth Measuring Station of the Global Atmosphere Network for Climate Research (PollyNet) began work at the Physicotechnical Institute of the Russian Academy of Science and Technology. The new station is the first in Central Asia and is located within the global dust belt, stretching from Morocco to China.
The PhTI AS RT also cooperates with the College of Atmospheric Sciences of Lanzhou University of China (https://en.lzu.edu.cn/). Memorandum of Understanding was signed in 2018. According to this document, cooperation is planned until 2025. At present, work is underway on the creation of the Center for Climate and Air Quality Research at the PhTI AS RT.
The PhTI AS RT also cooperates with the Key Laboratory of Cryospheric Sciences of the Northwest Institute of Ecology of the Environment and the Environment and Resources of the Chinese Academy of Sciences in Lanzhou. As part of the collaboration, a joint study of aerosol and elemental carbon is planned. We note that a general aerosol is already being collected at the scientific training ground of the PhTI AS RT. In terms of the installation of a new analyzer – the AE33 aerialometer of this Institute in the research site of the PhTI AS RT in order to study elementary carbon.
The problem of taking into account the effect of thermal non-linearity of all layers of a photoacoustic (PhA) chamber (gas-sample-substrate) during the formation of a PhA signal in condensed media for the case of volume absorption of optical radiation is solved. Theoretically, the features of the second harmonic generation of the PhA of the substrate signal during volumetric absorption of optical radiation by condensed media of various physical nature are investigated. A digital temperature sensor has been developed for direct measurement of the temperature of the rear side of samples in open PhA cells. Numerical calculations of nonlinear thermooptical problems are carried out on the basis of theoretically obtained fundamental solutions; The features of the applied application of optoacoustic spectroscopy of aerosol and gaseous substances are analyzed.
The direction of the use of physical methods in medicine has been developed. Among them are traditional methods of cryotherapy, which are based on liquid nitrogen, magnetotherapy of tumors, laser therapy and molecular spectroscopy methods in order to develop new methods of diagnosis and control of the course of treatment. Research is being conducted on the use of physical methods for early diagnosis and therapy in medicine.
The scientific ties of the institute are developing and strengthening, both with scientific institutions of the CIS countries and with scientific institutions of non-CIS countries. International cooperation is carried out through agreements on scientific and technical cooperation and international projects.
The Agreement on scientific and technical cooperation between the Physical Institute. P.N. Lebedev Russian Academy of Sciences and PhTI AS RT for 2009-2014, concluded August 29, 2009. Within the framework of this agreement, research is being conducted on cosmic ray physics, with the participation of the Pamir-Chakaltaya International Research Center.
The Laboratory of Atmospheric Physics, PhTI AS RT closely collaborates with the Laboratory of Climate Theory, Institute of Atmospheric Physics named after A.M. Obukhov RAS, with the Eurasian University. L.N. Gumilyova (Kazakhstan, Astana). With the Department of General Physics and Wave Processes, Faculty of Physics, Moscow State University M.V. Lomonosov, Moscow, Russia.
Under the Agreement on scientific and technical cooperation between the Tobolsk State Social and Pedagogical Academy named after D.I. Mendeleev and the PhTI AS RT from March 13, 2010 are conducting acoustic studies of liquid crystals.
The molecular spectroscopy laboratory still has close scientific contacts with the molecular modeling and spectroscopy laboratory of the Institute of Physics named after B.I. Stepanova of the National Academy of Sciences of the Republic of Belarus for research in the field of IR spectroscopy of biosubstrates.
ICNR collaborates with the Institute of Nuclear Physics of the Republic of Kazakhstan, the Institute of Nuclear Physics of the Academy of Sciences of the Republic of Uzbekistan and the Joint Institute for Nuclear Research (Dubna, Russia).
As part of the projects of the International Science and Technology Center, the Atmospheric Physics Laboratory carries out scientific cooperation with collaborators from France, Portugal and the USA. ICNR continues to collaborate with the Sandia National Laboratory of the United States and the Vienna Technical Institute (Austria). Research in the field of modeling effective neutron radiation detectors is carried out jointly with the Hachn Meitner Institute (Germany) and the Physics and Technology Institute of Braunschweig (Germany).
At the PhTI AS RT there are two Dissertation Councils. The dissertation council 6D.KOA-031 of the Higher Attestation Commission of the Republic of Tajikistan under the President of the Republic of Tajikistan on the basis of the PhTI AS RT and the Dissertation Council DM 737.004.10 of the Higher Attestation Commission of the Russian Federation on the basis of the Tajik National University and PhTI AS RT.
The dissertation council 6D.KOA-031 on the defense of dissertations of doctors of phislophia (PhD), a doctor in the specialty 6D060400 – Physics and 6D071700 – Heat power engineering was created by order No. 72 of the Chairman of the Higher Attestation Commission under the President of the Republic of Tajikistan dated 06.12.2017.
We also note that since 2018, the Council for Cooperation in the Field of Fundamental Science of the CIS Member States has been considering, in particular, the issue of giving the status of the basic organization of the CIS member states in the field of training scientific personnel in the physical and technical sciences of the PhTI AS RT. In 2019 and 2020 The CIS Executive Committee in Minsk hosted a meeting of the Working Group on the development of regulations on the basic organizations of the CIS member states in the field of training scientific personnel in the physical and physical-technical sciences, as well meeting of expert group on the coordination of draft regulations on the basic organizations of the CIS countries, respectively.
Practical use of research results
Based on the announcement of the industrialization of Tajikistan as the fourth strategic goal (Message from the President of the Republic of Tajikistan to the Majlisi Oli of the Republic of Tajikistan, December 26, 2018), the PhTI AS RT regularly takes practical steps and is actively working on the implementation of scientific developments in a number of industrial enterprises, as well as in medical institutions. In particular, in the Tajikcement unitary state enterprise in Dushanbe, on the basis of contracts, work was carried out on the selection and delivery of bricks with the appropriate physical and mechanical properties for the inner lining of a high-temperature furnace. Another area of implementation under the contract was to develop four new designs of high-temperature armored plates for the mill with their subsequent manufacture. Technical characteristics of armor plates correspond to certain mechanical and strength requirements, as well as heat resistance and durability. An agreement has been completed on the selection and delivery of a cable 51 and 25.5 mm thick that meets mechanical and strength requirements for air supply of feedstock to the production site of Tajikcement State Unitary Enterprise.
With the joint work of scientists of the PhTI AS RT, nanostructured solar cells based on carbide were introduced into production.
At the Shifo Medical and Diagnostic Center, Pharma LLC, new cryosurgical instruments have been adopted for use, the design of which is simpler and more convenient. New anti-cryoadhesive coatings are tested, the properties of which vary depending on the requirements of therapy. At the same time, tests and new diagnostic methods, condition monitoring, etc. are being tested.
The result of the research and practical application of the developed methods of radioecological research of sampling methods was their implementation in practical work during the organization of radioecological research on the territory of the Republican Radioactive Waste Disposal Center (RRWDC), in particular, six acts of the implementation of research at the RRWDC of the Main Directorate were received beautification of Dushanbe.
According to the Aga Khan Foundation MSDSP Project: TACIS-ILCA-III-2010 “Use of renewable energy in the mountains” in Khatlon region (Shuroabad, Khovaling, Muminabad), 3 systems were proposed, 3 wind power and 15 photovoltaic installations were installed and commissioned.
Upgraded 4 biogasification plants. The listed devices are installed in schools and private homes in remote mountain villages. Solar collector systems for heating water and power plants installed in the Hirmanjo outpost of the Border Guards of the Republic of Tajikistan. (The project is funded by the US Embassy in Tajikistan). Solar collector systems for heating water and power plants were installed in the rural health center of the jamoat Bozorboy Burunov, Vakhdat (the project was funded by UNDP).
Personnel are trained in nanotechnology and information technology, as well as in renewable energy sources and condensed matter physics in scientific centers of Russia (JINR, Lebedev Physical Institute, Institute of Crystallography), Belarus, Kazakhstan, short internships and participation in summer and winter schools of young specialists from the CIS countries are practiced (Moscow, Dubna, Astana).
An employee of the theoretical physics sector (F.Sh.Shokirov) for the project “Creating a Package of Applied Programs for the Mathematical Modeling of Nonlinear Excitations in Two-Dimensional Magnetic Systems” won a diploma of the Laureate of the Open Competition for Youth Innovation Projects in the Field of Humanities, Natural Sciences in the CIS Member States. The project “Study of the theoretical foundations of quantum computing in multilevel systems based on the coherent state technique” successfully passed an examination at OJSC Technopark Sistema-Sarov and was awarded the certificate of the Sistema-Sarov Youth Innovation Center.
Young employees of the PhTI AS RT are widely involved in international schools held at the Joint Institute for Nuclear Research (Dubna), CERN, the National Nuclear Center of the Republic of Kazakhstan (Astana), and actively participated in the International School of Young Scientists of the CIS Countries “Related Problems of Physics and Astrophysics of High and superhigh energies ”using the base of the Pamir-Chakaltay International Research Center.
Under existing agreements on cooperation with TNU, TTU them. M. Osimi, TSPU im. S. Aini, TSMU named after A. Sino, KSU named after B. Gafurov, Khujand TGUPBP and Khorog State University. M. Nazarshoyeva provides leadership to graduate students and applicants from leading experts of the Institute, joint research is being conducted on the basis of the PhTI AS RT.
Thus, in the future, the S.U.Umarov Physical – Technical Institute of the Academy of Sciences of the Republic of Tajikistan plans to coordinate the development and implementation of joint research projects and educational programs with research and educational institutions of a physical and technical profile, both of the CIS member states and of foreign countries. To carry out training, retraining and advanced training of specialists in the field of physical and technical sciences, as well as preparing recommendations for improving the cooperation of the CIS member states in this field. To study the processes and problems of integration and productive cooperation in the physical and technical industry in the CIS member states and abroad, taking into account current global trends. Facilitate the exchange of organizational, educational and pedagogical experience of professorship and teaching and the achievements of research work based on cooperation with research and production enterprises in the field of physical and technical sciences in the CIS member states and abroad.
The staff of the S.U.Umarov Physical – Technical Institute of the Academy of Sciences of the Republic of Tajikistan is full of hopes and aspirations in solving a number of fundamental and applied problems that are important both for physical science and affecting the vital interests of our country. The staff of the institute sees its contribution to strengthening the independence of their homeland, to creating the foundation of a prosperous state precisely in the innovative development of the country’s productive potential based on advanced scientific developments and the introduction of modern technologies in industry.