SIBERIAN JOURNAL OF PHYSICS. Scientific Journal. 2022. V17, i 1

 

High-Energy and Accelerator Physics, Physics of High-Temperature Plasma

 

Sandalov E. S., Sinitsky S. L., Skovorodin D. I., Nikiforov D. A., Logachev P. V., Bak P. A., Zhivankov K. I., Kenzhebulatov E. K., Petrenko A. V., Nikitin O. A., Akhmetov A. R., Protas R. V., Khrenkov S. D., Zhuravlev I. A., Penzin I. V., Don A. R. Investigation of Transverse Instability of a High-Current Relativistic Electron Beam in a Linear Induction Accelerator. // Siberian Journal of Physics, 2022, vol. 17, no. 1, pp. 5–22. (in Russ.) DOI 10.25205/2541-9447-2022-17-1-5-22

The article presents the results of studies on the transverse instability of a high-current relativistic electron beam de-veloping in a linear induction accelerator LIA for 5 MeV electron energy, which is created at the BINP SB RAS to-gether with RFNC VNIITF. These results were obtained using a software package that makes it possible to simulate the dynamics of the instability development, as well as to calculate the increment of this instability averaged over the accelerator length. The package consists of four main parts. The first of them, made on the base of a three-dimensional model of the accelerating module electrodynamic system of the LIA, allows calculating the main characteristics of electromagnetic dipole modes of such a module, the second and third parts are designed to find three-dimensional accelerating electric and focusing magnetic fields, respectively. In the last part of the package, a system of ordinary differential equations is solved that describes both the motion of beam macroparticles in electric and magnetic fields, including the eigenmode fields, and the excitation of the mode fields by the electron beam. The adequacy of the physical models used in the software package was tested by comparing the spectra of field oscillations in the accelerator modules obtained in calculations and recorded in the experiment. On the base of the data obtained, the main regularities of the transverse beam instability development in the frequency range df = 0.3–1.1 GHz were revealed, and possible methods for suppressing this instability in the LIA were proposed.

Keywords
linear induction accelerator, high-current relativistic electron beam, beam transverse instability, accelerator module, dipole oscillations

Funding
The main part of the research was carried out at the Institute of Nuclear Physics SB RAS: the works described in sec-tions 3.2 and 3.3 were supported by the Russian Science Foundation (project ¹ 19-12-00212), and in other sections were supported by the Russian Foundation for Basic Research (project ¹ 19-32-90057). Experiments with an electron beam at an energy of 5 MeV were carried out in collaboration with RFNC VNIITF.
The authors express their sincere gratitude to A. V. Burdakov, A. V. Arzhannikov, P. V. Kalinin, V. N. Volkov for useful remarks and discussions in the course of the research.

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Kuksanov N. K., Vorobev D. S., Salimov R. A., Fadeev S. N. The High Voltage Source for the ELV-15 Accelerator. // Siberian Journal of Physics, 2022, vol. 17, no. 1, pp. 23–33. (in Russ.) DOI 10.25205/2541-9447-2022-17-1- 23-33

The article describes modelling of the high voltage source of the ELV-15 accelerator. The electromagnetic parameters of the rectifier, the magnet filed distribution, the parameters of primary and secondary winding are considered. Ripples and stability of the accelerating voltage are evaluated. The strength of the electric field in the source is considered.

Keywords
high voltage rectifier, particle accelerator, ELV

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Physics of a Fluid, Neutral and Ionized Gases

 

Adamov N. P., Mishchenko N. A., Chasovnikov E. A. About the Dynamic Damping Coefficients of a Segmental-Cone Model at Mach M = 2.3. // Siberian Journal of Physics, 2022, vol. 17, no. 1, pp. 34–46. (in Russ.) DOI 10.25205/2541-9447-2022-17-1-34-46

In order to describe the nonlinear behavior of oscillation amplitude of the segmental-conical model on a transversive rod setup in a wind tunnel at Mach Ì = 2, a polynomial function of damping derivatives was used. Polynom of the 4th degree as a function of viscous damping allowed to describe two limit cycles observed in experiments. Coefficients of the polynom were determined and showed sufficient agreement with a direct numerical solution of the proposed dynamic equation.

Keywords
Van der Pole equation, dynamic stability of reentry vehicles, aerodynamic damping, free oscillation setup

Funding
The research was carried out within the framework of the Program of Fundamental Scientific Research of the state academies of sciences in 2013–2020 (project no. ÀÀÀÀ-À17-117030610125-7). Experiments were carried out using the equipment of the Joint Access Center “Mechanics”

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Yaskin A. S., Zarvin A. E., Kalyada V. V., Dubrovin K. A., Khudozhitkov V. E. Flow of Ethanol into a Medium with Varying Degrees of Rarefaction. // Siberian Journal of Physics, 2022, vol. 17, no. 1, pp. 47–64. (in Russ.) DOI 10.25205/2541-9447-2022-17-1-47-64

Experimental results of observation of ethanol microjets flowing into a highly rarefied medium (vacuum) through a nozzle are presented. The investigation of the outflow process was carried out both horizontally and vertically in the direction of gravity, when the liquid was expelled from the source. The condition of keeping constant the residual background pressure in the vacuum chamber is much lower than the saturated vapour pressure of the working liquid at a given temperature of the blast. The possibility of simulation of complex processes of the flow of micro-liquids in a space with a given rarefied atmosphere on a compact vacuum gas-dynamic test bench is shown. It is found that the continuous efflux from a thin capillary or a hole of small diameter into a vacuum or a strongly rarefied gaseous medium differs significantly from the well-studied modes of efflux into a dense gaseous medium, as well as from the pulse modes of efflux into a vacuum. The paper describes the main features of the flow and the conditions of the instability emergence. It is shown that the long-term flow of a liquid microjet in a vacuum has a high degree of surface instability, with a large number of sudden changes in direction, structure and observed density. An explanation for the causes of microjet failure, caused mainly by a combination of capillary instability and intense evaporation of superheated liquid from the surface of the jet, is proposed. The formation of surface gas caverns causing explosive collapse of the microjet with ejection of vapor-liquid droplets is established.

Keywords
liquid microjet, surface instability, modelling of vacuum conditions, ethanol, saturated steam

Funding
The work was performed using the shared equipment center “Applied physics” of the NSU Physics Department with the financial support from the Ministry of Science and Higher Education of the Russian Federation (project number FSUS-2020-0039) and RFBR (grant number 20-01-00332/20)

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Gulov M. A. Optimization of Parameters of Laser Cladding of the Powder Based on Nickel-Aluminium System. // Siberian Journal of Physics, 2022, vol. 17, no. 1, pp. 65–77. (in Russ.) DOI 10.25205/2541-9447-2022-17-1- 65-77

In this work, the parameters of laser cladding were optimized to obtain a high-quality single track. Nickel aluminide powder (Ni3Al) – PN85Yu15 was used as the surfacing material. 60 samples were obtained, deposited at various parameters of power, scanning speed, position of the focus of the laser beam relative to the surface of the powder layer. The geometric characteristics of the obtained single tracks were measured, graphs of their dependence on the scanning speed were plotted. It was found that the sizes of single tracks decrease with increasing speed. An increase in the power of laser radiation leads to an increase in width and height of the track, as well as the depth of penetration of the sub-strate. The dependence of the geometric characteristics of the tracks on the temperature of the melting pool has been investigated. The microhardness of the obtained samples was also measured, and a weakly expressed dependence of the microhardness on the laser scanning speed was found. It was found that the microhardness of the obtained samples correlates with the amount of energy imparted to the powder layer and the temperature of the melting pool. It was also found that the set of experimental data is described in generalized spatial and energy coordinates by a linear dependence.

Keywords
laser cladding, selective laser melting, single track, aluminum nickelide, PN85Yu15

Funding
The work was carried out within the state task ¹ 121030900259-0

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Solid-State and Semiconductor Physics, Physics of Nanostructures

 

Rybak A. A., Kuznetsov S. À., Arzhannikov A. V., Nikolaev N. A. Design of a Narrowband Filter for Implementing the Undersamping Method in Terahertz Time-Domain Spectrometers. // Siberian Journal of Physics, 2022, vol. 17, no. 1, pp. 78–92. (in Russ.) DOI 10.25205/2541-9447-2022-17-1-78-92

In this paper, we propose a design of a narrow-band quasi-optical filter with a central frequency v = 806 GHz (L = 372 mkm) suitable for the implementation of the undersampling technique in terahertz time-domain spectroscopy. The frequency was chosen to monitor the absorption line of the molecular gas CO in the local transparency window of the atmosphere. The filter is designed as the Fabry-Perot etalon based on a polypropylene film with frequency-selective surfaces (FFS) on both sides consisting of square slots in a sprayed aluminum layer. Through numerical simulation of the transmission of the proposed structure, we defined that the optimum ratio of the width of the metal bridge a to the pitch g of the FSS lies in the vicinity of a/g = 0.5. For g less than half of the operating wavelength L, the FWHM of the filter is less than 4%, which is sufficient for the implementation of the undersampling method in terahertz time-domain spectroscopy.

Keywords
terahertz time-domain spectroscopy, frequency-selective surfaces, quasi-optical filters, undersampling

Funding
The reported study was funded by RFBR according to the research project ¹ 20-32-90137.
The authors acknowledge the NSU Shared Equipment Center “VTAN” for the equipment provided for the project

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Educational and Methodical Provision of Teaching of Physics

From Editor

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Àëåêñàíäðîâ Â. À., Áîãîÿâëåíñêàÿ Î. À., Óëüÿíîâ À. Ï. Êàôåäðà âûñøåé ìàòåìàòèêè ôèçè÷åñêîãî ôàêóëüòåòà Íîâîñèáèðñêîãî ãîñóäàðñòâåííîãî óíèâåðñèòåòà

Aleksandrov V. A., Bogoyavlenskaya O. A., Ulyanov A. P. Higher Mathematics Chair of the Physics Department at Novosibirsk State University. // Siberian Journal of Physics, 2022, vol. 17, no. 1, pp. 94–103. (in Russ.) DOI 10.25205/2541-9447-2022-17-1-94-103

The article presents the higher mathematics chair of the physics department at Novosibirsk State University, describing the history of its creation, its traditions, and methods used by its lecturers. The reader can also find here some general information about the staff and the courses taught.

Keywords
mathematical analysis, linear algebra, differential equations, complex analysis, probability theory, mathematical statistics, computational methods

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Alperovich V. L., Kvon Z. D., Latyshev A. V. Department of Semiconductor Physics of the Physics Department at Novosibirsk State University. // Siberian Journal of Physics, 2022, vol. 17, no. 1, pp. 104–117. (in Russ.) DOI 10.25205/ 2541-9447-2022-17-1-104-117

The Department of Semiconductor Physics at the Faculty of Physics, Novosibirsk State University, trains specialists for research work in the field of condensed matter physics, semiconductor physics and the physics of low-dimensional systems and nanostructures. It also provides knowledge enabling its graduates to participate in developing semiconductor technologies, improving existing and creating new opto-, micro- and nanoelectronic devices. The article describes the history of the creation of the department, the main stages of the formation of training courses and work on the organization of students’ research practice in the laboratories of Rzhanov Institute of Semiconductor Physics (ISP), which is the basic Institute for the department. An overview of the training courses taught at the department for the preparation of bachelors and masters is given. It is told about the scientific and technological achievements of ISP, and about unique measuring, analytical and technological equipment available in the laboratories of the Institute, which is the basis for organizing research work of students at a high scientific and methodological level.


Keywords
semiconductor physics, condensed matter physics, solid state theory, surface physics, low-dimensional systems, heterostructures, electronic transport, atomic structure, heteroepmiaxy, optical phenomena, radiation physics, nanodiagnostics, quantum technologies

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Annenkov V. V., Arzhannikov A. V., Bagryansky P. A., Beklemishev A. D., Davydenko V. I., Sinitsky S. L., Skovorodin D. I., Sudnikov A. V., Chernoshtanov I. S., Fedorenkov E. A., Shoshin A. A. Department of Plasma Physics of the Physics Department at Novosibirsk State University. // Siberian Journal of Physics, 2022, vol. 17, no. 1, pp. 118–141. (in Russ.) DOI 10.25205/2541-9447-2022-17-1-118-141

The article describes the system of scientific-engineering training at the Plasma Physics Department at the Physical Department, NSU with the active participation in this process of researchers from the plasma laboratories of the Budker Institute of Nuclear Physics of the Siberian Branch of the Russian Academy of Sciences. The text gives an idea of plasma as a subject studied in this department, and then consistently reflects the following information: the history of the department, the special courses taught in the department, the subjects of undergraduate and graduate theses, the achievements of graduates of the department in the last decade. Taking into account the main topic of scientific research in the plasma laboratories of the BINP SB RAS, the text gives an overview of the work at the plasma facilities operating at the institute and outlines the prospect of creating a next-generation linear plasma trap (GDMT). Particular attention is paid to the prospect of using open magnetic systems for hot plasma confinement in relation to solving the problem of controlled thermonuclear fusion, since these systems should serve as the field of primary activity for future graduates of the Department of Plasma Physics.

Keywords
Plasma Physics Department, magnetic plasma confinement, neutral atom beam, relativistic electron beam, beam-plasma system

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Shalagin A. M., Ilichev L. V. Quantum Optics Department of the Physics Department at Novosibirsk State University. // Siberian Journal of Physics, 2022, vol. 17, no. 1, pp. 142–149. (in Russ.) DOI 10.25205/2541-9447-2022-17-1-142-149

There presented an information on the department of Quantum optics of the Novosibirsk State University. The brief history of the Department since its foundation by the corresponding member of the Russian Academy of Sciences, Sergei G. Rautian, and main educational directions are described along with their relations to scientific research of teachers and students of the Department.

Keywords
laser physics, nonlinear spectroscopy, THz spectroscopy, nanophotonics, fiber optics

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Glushak A. A. Chair of Physical and Technical Informatics of the Physics Department at Novosibirsk State University. // Siberian Journal of Physics, 2022, vol. 17, no. 1, pp. 150–154. (in Russ.) DOI 10.25205/2541-9447-2022-17-1-150-154

The Chair of Physics and Technology of the Physics Department trains specialists in the field of software and hardware for physical experiments, storage, and processing of information. The program of the courses involves the study of programming methods, information technologies and hardware for experimental installations in addition to fundamental education in physics and mathematics, which all students of the physics department of NSU receive. The graduates of the chair are specialists in the field of information technology with universal general physical training.

Keywords
the Physics Department, experiment automation, information technology

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Telnov V. I. Accelerator Physics Chair of the Physics Department at Novosibirsk State University. // Siberian Journal of Physics, 2022, vol. 17, no. 1, pp. 155–160. (in Russ.) DOI 10.25205/2541-9447-2022-17-1-155-160

The article tells about the Accelerator Physics Chair of the Physics Department of the Novosibirsk State University, based at the Budker Institute of Nuclear Physics SB RAS.

Keywords
accelerator physics

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Brief Communications

Achasov N. N. Four-Quark Nature of Light Scalar Mesons. // Siberian Journal of Physics, 2022, vol. 17, no. 1, pp. 161–165. (in Russ.) DOI 10.25205/2541-9447-2022-17-1-161-165

The contribution of Novosibirsk physicists to the discovery of the four-quark nature of light scalar mesons f0(980) and a0(980) is described.

Keywords
four-quark states, light scalar mesons, experimental results

Funding
The work was carried out within the framework of the state task of the Institute of Mathematics of the Siberian Branch of the Russian Academy of Sciences, project no. 0314-2019-0021.
The author is grateful to A. V. Kiselev and G. N. Shestakov for help in preparing the article

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Instructions to Contributors

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