Gas Discharge Physics Research Articles

XIII Scientific Technical Conference on Low Temperature Plasma During the Deposition of Functional Coatings

In the city of Kazan from November 2 to November 4, 2021 on the basis of the Kazan Federal University hosted the XIII Scientific Technical Conference on Low Temperature Plasma during the Deposition of Functional Coatings.One of the main tasks of the conference is to discuss and develop the fundamental principles of plasma deposition of functional coatings. Conference papers were presented in the following areas:- Physics of gas discharge;- Physical processes in low-temperature plasma when applying functional coatings;- Thermodynamic, portable and optical properties of low-temperature plasma in coating processes;- Interaction of plasma and high-energy ion beams with a solid;- Combustion processes and heat and mass transfer in multiphase media;- Dusty plasma;- Plasma chemistry. Electrochemistry;- Diagnostics of low-temperature plasma;- Characteristics of coatings obtained using low-temperature plasma;- Application of ion-plasma coatings.Within the framework of the conference, a school for young scientists is held, lectures by leading scientists and specialists in the field of low-temperature plasma application are held.Gas-discharge plasma is widely used in various fields of science and technology. Plasma is used in industry, medicine, ecology and is the basis of various devices and technologies, for example, it is used in the technology of applying functional coatings.The friendly atmosphere at the XIII Scientific Technical Conference on Low Temperature Plasma during the Deposition of Functional Coatings allowed it to become an excellent platform for the exchange of experience and generation of new ideas in the field of physics and the use of low-temperature plasma.This year, studies of gas-discharge phenomena in electrolytes, studies on the use of ultrasound to obtain metal powder in a plasma discharge electrolyte, calculations of electro-contact firing of steel powders were presented. A series of works is devoted to heat and mass transfer in multiphase media and the study of materials and coatings obtained using low-temperature plasma.List of Organizing Committee, Scientific Committee are available in this Pdf.

The principle of minimal power

This article is devoted to the memory of Yuri P Raizer, who passed away in 2021. He left a noticeable trace in gas discharge physics. The principle of minimal power (the state that requires minimal power is most probable) is thoroughly used in his books. Although the fundamental laws of physics do not imply this ad hoc principle, a detailed analysis of underlying phenomena can often reveal why nature prefers this path. Raizer illustrated this principle for plasma stratification, formation of electrode spots, discharge constriction, the shape of an arc channel, etc. We argue that the nonlinearity of equations describing gas discharges can often justify the realization of a plasma state maintained at minimal electric power. This nonlinearity appears because small groups of energetic electrons often control the ionization processes. The number of these electrons depends strongly on the ratio of the electric field to gas density, E/N. Under certain conditions, the ionization rate can also depend nonlinearly on electron density due to stepwise ionization and Coulomb collisions. We use the principle of minimal power to illustrate some of Raizer’s contributions to gas discharge physics from a single point of view. We demonstrate that nonlinearity of ionization processes in gas discharges can substantiate this principle for plasma stratification. However, striations of s, p, and r types in neon could exist with minimal or no ionization enhancement. This reminds us of Raizer’s warning that applying the minimal power principle could lead to erroneous predictions, and a proper theory is required in each case to justify its use. ‘The phenomenon of striations satisfies the principle of minimal power’ – Yuri Raizer

Experimental Study on the Transient Disturbance Characteristics and Influence Factors of Pantograph–Catenary Discharge

The transient electromagnetic disturbance generated by arcing discharge between the pantograph and catenary can pose a significant risk to the safe operation of electrified railways. In order to better comprehend its properties, a pantograph–catenary discharge generating device is designed to simulate the discharge phenomenon with moving electrodes in this experimental investigation. The effects of the applied voltage, the gap distance, and the relative motion between the pantograph and catenary on the time- and frequency-domain features of the discharge current and electromagnetic field are investigated. The variation trends of pulse peak current, rise time, pulse repetition frequency, maximum amplitude, and characteristic frequency in the radiation spectrum are retrieved under varying experimental settings, and the effect mechanisms are derived from the physics of gas discharge. A dynamic discharge test is conducted in this study in order to further understand the effect of electrodes’ relative motion on discharge characteristics. The results indicate that lateral sliding motion of the pantograph along the track has a negligible effect on the transient discharge, whereas a faster vertical approaching motion between the pantograph and catenary generates a larger pulse current peak, a steeper rise front-edge, and a higher radiation intensity.

Revisiting the numerical stability/accuracy conditions of explicit PIC/MCC simulations of low-temperature gas discharges

Particle-in-cell (PIC) with Monte Carlo collisions is a fully kinetic, particle based numerical simulation method with increasing popularity in the field of low temperature gas discharge physics. Already in its simplest form (electrostatic, one-dimensional geometry, and explicit time integration), it can properly describe a wide variety of complex, non-local, non-linear phenomena in electrical gas discharges at the microscopic level with high accuracy. However, being a numerical model working with discretized temporal and (partially) spatial coordinates, its stable and accurate operation largely depends on the choice of several model parameters. Starting from four selected base cases of capacitively coupled, radio frequency driven argon discharges, representing low and intermediate pressure and voltage situations, we discuss the effect of the variation of a set of simulation parameters on the plasma density distribution and the electron energy probability function. The simulation parameters include the temporal and spatial resolution, the PIC superparticle weight factor, as well as the electron reflection and the ion-induced electron emission coefficients, characterizing plasma–surface interactions.

2Nd International Conference “Gas Discharge Plasma and Synthesis Of Nanostructures 2021

In the city of Kazan from December 1 to December 4, 2021 on the basis of the Kazan National Research Technical University named after V.I. A.N. Tupolev-KAI hosted the II International Conference "Gas Discharge Plasma and Synthesis of Nanostructures" was held. The main organizers of this conference are KNRTU-KAI, KFU, Academy of Science Republic of Tatarstan. This event has become a notable event for the community of scientists and researchers involved in the physics of gas discharges and the synthesis of nanostructured materials. The conference discussed issues related to fundamental, problematic issues in the physics of gas discharges, such as the theory of arc plasma, high-frequency discharges, microwave discharges, glow discharge. Nevertheless, the main attention was paid to the problems of using gas discharge plasma for the synthesis of nanostructures. It is gratifying that there are results in this direction that are ready for industrial application. This year, the topic of the conference additionally includes a section on the physics of non-ideal and dusty plasma. On this topic, several plenary reports were made at once, which were presented by leading world scientists. The conference became a platform where completely new fundamental results that are at the forefront of science were presented. The vast majority of the presented works were presented for the first time.Organizing Committee, Scientific Committee are available in the pdf

Formation and evolution of striation plasma in high-pressure argon glow discharge

The self-organized striation phenomenon in the positive column region of glow discharge plasma is a basic problem in gas discharge physics, which involves rich physics such as electron dynamics, transport process, discharge instability and nonlinear phenomenon. It is an important topic in basic physics and practical application. In this work an argon glow discharge striation plasma at high pressure is reported. The electrical, optical and ionization wave propagation characteristics of the striation plasma, and the evolution of the striation plasma with pressure and impurity gas are investigated experimentally. The generation and quenching mechanism of argon striation plasma are analyzed. The results show that the striation length is about 1.5 mm, and decreases with pressure increasing, and the velocity and frequency of the ionization wave are estimated at 1.87 m/s and 1.25 kHz, respectively. The measurement of optical emission spectrum shows that the generation of striation plasma is probably related to the argon metastable atoms. The stepwise ionization process caused by metastable atoms triggers off an ionization instability. The instability propagates in the form of ionization wave, which leads the plasma parameters to be modulated longitudinally, thus, forming an alternating bright and dark striation plasma. The adding of nitrogen can effectively quench metastable argon atoms and change the electron energy distribution function, which destroys the instability conditions of the plasma, therefore, the striation plasma disappears. This work provides a new insight into the understanding of the formation and annihilation mechanism of glow discharge striation plasma at high pressure.

XII Scientific Technical Conference On Low Temperature Plasma During The Deposition Of Functional Coatings

In the city of Kazan from November 10 to November 12, 2020 on the basis of the Kazan Federal University hosted the XII Scientific Technical Conference on Low Temperature Plasma during the Deposition of Functional Coatings.One of the main tasks of the conference is to discuss and develop the fundamental principles of plasma deposition of functional coatings. Conference papers were presented in the following areas:– Physics of gas discharge;– Physical processes in low-temperature plasma when applying functional coatings;– Thermodynamic, portable and optical properties of low-temperature plasma in coating processes;– Interaction of plasma and high-energy ion beams with a solid;– Combustion processes and heat and mass transfer in multiphase media;– Dusty plasma;– Plasma chemistry. Electrochemistry;– Diagnostics of low-temperature plasma;– Characteristics of coatings obtained using low-temperature plasma;– Application of ion-plasma coatings.Within the framework of the conference, a school for young scientists is held, lectures by leading scientists and specialists in the field of low-temperature plasma application are held.Gas-discharge plasma is widely used in various fields of science and technology. Plasma is used in industry, medicine, ecology and is the basis of various devices and technologies, for example, it is used in the technology of applying functional coatings.The friendly atmosphere at the XII Scientific Technical Conference on Low Temperature Plasma during the Deposition of Functional Coatings allowed it to become an excellent platform for the exchange of experience and generation of new ideas in the field of physics and the use of low-temperature plasma.List of Organizing Committee are available in this pdf.

1st All-Russian (With International Participation) Conference “Gas Discharge Plasma and Synthesis of Nanostructures 2020

B A Timerkaev1, I I Fairushin1,2,3 1 Kazan national research technical university named after A. N. Tupolev-KAI, Kazan, Russia 2 Kazan Federal University, Kazan, Russia 3 Joint Institute for High Temperatures of RAS, Moscow, Russiabtimerkaev@gmail.com, fairushin_ilnaz@mail.ruIn the city of Kazan from December 2 to December 5, 2020 on the basis of the Kazan National Research Technical University named after V.I. A.N. Tupolev-KAI hosted the First All-Russian Conference with international participation “Gas-Discharge Plasma and Synthesis of Nanostructures”. Within the framework of this event, the exchange of research experience of both experimenters and theorists involved in the physics of gas discharges, modeling of processes in gas-discharge plasma, synthesis of nanostructures, physicochemical processes in gas, plasma and gas discharges, phenomena of self-organization in plasma, interaction of plasma with matter took place, plasma and laser nanotechnology, plasma chemistry and plasma dynamics. 7 plenary and 35 oral reports were presented at the conference. A poster session was held, in which 26 reports were presented. The reports made within the framework of the conference reflected the current state of science in the field of gas-discharge plasma physics and synthesis of nanostructures. The conference participants were united by a common interest in the discussed problems. The conference has become a productive platform for the exchange of ideas and acquaintance with new results from related areas of fundamental and applied science. The participation of a large number of young scientists testifies to the continuity of scientific traditions in the scientific schools presented at the conference.List of Organizing Committee, Scientific Committee are available in this Pdf.

Modeling of Cavity Discharges under AC and DC Voltage — Part II: Opportunities of the Dipole-based PD Model

To explain the occurrence of partial discharges (PD) in gaseous cavities embedded in the bulk dielectric of HV equipment, as well as to analyze the associated PD transients, two fundamental approaches have been proposed in the past, which are commonly referred to as network-based and dipole-based PD model. The first one has been reviewed critically in Part I of this publication, while this Part II is addressed to the dipole-based PD model. This alternative approach, which was promoted by Pedersen in the 1980, is based on the fundamentals of the gas discharge physics and adopts the electromagnetic field theory to treat the electromagnetic transients, which are associated with the establishment of an electrical dipole as consequence of a cavity discharge. However, understanding this more sophisticated concept needs a deep knowledge of the electromagnetic field theory based on Maxwell's equations. Presumably, this may be the reason why the dipole-based PD model is rarely adopted in the relevant literature. However, introducing some simplifications, this approach becomes easy understandable and can simply be handled, as highlighted in this paper based on some chosen case studies of practical interest.

Modeling of Cavity Discharges under AC and DC Voltage — Part I: Limitations of the Network-based PD Model

To explain the phenomena of partial discharges (PD) in gaseous cavities embedded in the bulk dielectric of HV equipment and their components as well as to analyze the associated PD transients, two fundamental approaches have been proposed in the past, which are commonly referred to as network-based PD model and dipole-based PD model. This paper is addressed to the first approach, while the second one will be reviewed in the Part II of this publication. Verifying the feasibility of the network-based PD model leads to results, which contradict the expectations from a physical point of view. The reason for that are simplified assumptions, which are inconsistent with the fundamentals of the gas discharge physics. Another shortcoming is the use of the classical network theory, although the field theory must be adopted to treat the PD transients. This leads to the conclusion that the traditional abc-model is only applicable to describe and explain he phenomena of cavity discharges qualitatively, but not to treat the PD transients quantitatively, as will be highlighted in more detail in this paper.

ELIMINATION OF ELECTRIC ARC STABILIZATION IN WELDING AND SOLDERING PROCESSES IN GLOW DISCHARGE

Background. Recent studies showed that low temperature plasma of a glow discharge that burns in the inert or active gases at the pressures below atmospheric is the perspective heating source for different processes related with the metal treatment let alone the diffusion bonding and brazing. However, in manufacturing practice, various conditions on the cathode surface (welded or treated samples) that may cause the changes of a glow discharge form or even its transition into an electric arc may appear. The prolonged arc action on the samples' surfaces inevitably leads to the disruption of the technological process and, consequently, to undesirable samples overheating.Objective. The purpose of this work is to improve the methods and to means of stabilizing the glow discharge in the technological processes of diffusion welding and soldering.Methods. Using the methods of the theory of gas discharge physics, electrodynamics and electromagnetism, the main causes of the appearance of external perturbations and instabilities that lead to the emergence of a stable arc discharge on the local sections of the surfaces of the welded parts were determined.Results. It is established that increasing of the electrode gap length in the conditions of the arc emergence to the values of 0.03–0.06 m for the time of 10-2–10-1 s is an effective means of quenching the electric arcs emerging in the stability infringinment of combustion of the power-current glow discharge in the processes of welding and soldering.Conclusions. The basic conditions for the loss of stability of a normal glow discharge and its transition to another, more stable form of gas discharge – electric arc – are determined. It is shown that the continuous action of the arc discharge on the surface of the welded parts leads to the melting of the latter, which requires the creation of additional arc extinguishing systems. The possibility of using multielectrode systems with movable anode sections as a means of eliminating the appearance and stabilization of an electric arc on the surface of parts welded is shown.

Scaling of conventional breakdown threshold: Impact for predictions of lightning and TLEs on Earth, Venus, and Mars

Our ability to observe extraterrestrial lightning is limited by our detection techniques, which rest mostly on our understanding of terrestrial lightning. However, gas discharge physics vastly depends on the environment. Here, we use the conventional breakdown threshold field, Ek, as a reference value for the initiation of atmospheric discharges. Its value depends on atmospheric composition, charge density, pressure, and temperature. Their effects are collectively approximated by scaling laws based on either atmospheric scale height, neutral density, or pressure. While these approximations have proven useful in numerical applications, they inherently limit the investigation of each specific parameter independently. To remove this limitation, we introduce a new model, which couples a Boltzmann solver with standard Global Reference Atmospheric Models (GRAM) and lets us perform systematic calculations of the breakdown at every altitude for realistic, altitude dependent gas mixtures. We develop Ek profiles from the ground to the ionosphere for Earth, Venus, and Mars and show that for all three planets, classic approximations based on atmospheric scale heights and neutral gas densities become inaccurate respectively above the tropopause and mesopause. We investigate specifically the role of atomic oxygen and atmospheric water. We conclude that hypothesized Martian discharge is favored by the planet's low atmospheric pressure. On Venus, discharges in the cloud layer require electrical conditions comparable to those in Earth thunderclouds but remain more likely than volcano lightning.

Preface

We are pleased to present the Proceedings of 18th International Workshop on Magneto-Plasma Aerodynamics (The Workshop) which was held in Moscow on April 09 – 11, 2019 at Joint Institute for High Temperatures of the Russian Academy of Sciences (JIHT).Every spring this Workshop is organized by JIHT under Scientific Council for Direct Energy Conversion, Scientific Council for Fluid Mechanics and Scientific Council for Low Temperature Plasma Physics of the Russian Academy of Sciences.The objective of the Workshop is to provide forum for presentation and discussion of recent progress in science and technology on magneto-plasma aerodynamics. The results of analytical and experimental studies of physics of gas discharge, physics of shock waves, plasma assisted ignition and combustion, MHD energy conversion, physical gas dynamics of high-speed airflows and their applications are discussed at the meeting.At the 18th Workshop there were presented 60 works in plenary and profiled sections: shock waves, electrical discharges, plasma assisted ignition and combustion, plasma aerodynamics, MHD&PA flow control and related problems.In this collection of papers there are published 30 selected articles and we are grateful to IOP Publishing for cooperation.Valentin Bityurin, PhD, DS, Chairman of WSMPA 2019Tatiana Kuznetsova, PhD, Scientific Secretary of WSMPA 2019

Applications of the gas discharge sustained by the powerful radiation of THz gyrotrons

The terahertz frequency range currently remains the least studied from the point of view of gas-discharge physics. Recent progress in its mastering is associated, first of all, with the creation of powerful sources of terahertz radiation - gyrotrons. Nevertheless, the discharge sustained by the powerful radiation of the terahertz frequency range is of interest not only from the fundamental point of view (because of its lack of knowledge), but also from the applied one. This paper presents results of investigations aimed at studying the point-like THz discharge as a source of vacuum ultraviolet radiation and at research of CW THz plasma torch existing at atmospheric pressure and therefore having promising applications in various fields: plasma medicine, plasma chemistry, material processing etc. It is shown that it is possible to create a point-like plasma in an inhomogeneous gas flow with the density above the cut-off one (4·1015 cm−3 for 0.67 THz). It has been demonstrated that such plasma is an effective source of VUV and EUV radiation. Investigations of the atmospheric plasma torch, sustained by CW sub-terahertz radiation (1 kW @ 0.26 THz), demonstrated the possibility of the creation dense non-equilibrium plasma (2·1015 cm−3) with electron temperature in the range from 1 to 2 eV.

Experimental study of the energy characteristics of a longitudinal Glow Discharge

Currently, a glow discharge is widely used not only as a gas-discharge light source or as an active medium for gas lasers, but also as an element of a plasma-chemical reactor, which allows for various chemical transformations in order to obtain new materials, modify and clean surfaces. Despite the fact that the structure and distribution of parameters in a classical glow discharge without gas flow and flat cylindrical electrodes are well known, to solve new technological problems, it is necessary to study glow discharge in discharge chambers with different electrode geometries and gas flow organization methods.The presence of a gas flow causes heterogeneity in the distribution of the parameters of a glow discharge, and can also affect the structure of its individual zones. Experimental study of the parameters of a longitudinal glow discharge will allow not only a better understanding of the physics of gas discharge, but also will make it possible to find ways to control these parameters, which is important for designing discharge chambers of various technological purposes. The article is devoted to a comprehensive experimental study of the distribution of potentials, field strength, current-voltage characteristics in a longitudinal glow discharge. The gas pressure P, its flow rate G, the discharge current strength I and its voltage U vary respectively in the ranges: P = (2–9) kPa, G = (0–0. 05) g / s, I = (30-80) mA, U = (1 - 2) kV.

Breakdown of the heavy noble gases in a focused beam of powerful sub-THz gyrotron

The results of experimental investigations of heavy noble gas breakdown thresholds in a focused beam of powerful subterahertz radiation are presented. The gas discharge, maintained by the powerful radiation of the terahertz frequency band, is a new specific object of gas discharge physics. This paper presents the experiments with pulsed gyrotrons capable of generating a power of 250 kW at a frequency of 250 GHz. The gyrotron wave beam was focused by means of quasioptical mirrors into the spot with a diameter less than 3 mm that provided intensity into the focal spot up to 3.5 MW/cm2. The achieved electrical field intensity was enough for gas breakdown into the range of pressure values of 1–1500 Torr for heavy noble gases (argon and krypton). The boundary values of field intensity for discharge existence were measured. Experimental data were compared to the analytical model of Raizer and Vyskrebentsev for monatomic gases.

12th International Conference “Aerophysics and Physical Mechanics of Classical and Quantum Systems” - APhM-2018

Preface12th International Conference “Aerophysics and Physical Mechanics of Classical and Quantum Systems” – APhM –2018 was held from 27 to 29 November 2018 at the Ishlinsky Institute for Problems in Mechanics of the Russian Academy of Sciences (IPMech RAS), Moscow, Russia. The conference was devoted to the 20-year anniversary of laboratory of Radiative Gas Dynamics of IPMech foundation.The aim of the Conference was to bring together leading scientists and discuss experience of new research findings, databases, computer codes, information on new instruments and methods of computational and experimental aerothermodynamics, physical experiments in the field of physical and chemical kinetics in gas dynamics, gas discharge physics, and plasma physics in the processes of combustion and explosion. This year the main scientific focus of the Conference was on high speed aerothermodynamics, and, first of all, development of numerical technology of validation of author’s computer codes.Founders, Organisation, Organising Committee, Program Committee, Editors and Invited Editors also present in this pdf.

INCREASING OF GLOW DISCHARGE STABILITY IN WELDING BY MEANS OF MULTISECTIONAL ELECTRODE SYSTEMS

Background. The glow discharge has been widespread as a source of surface heating for diffusion welding and soldering thanks to the possibility of regulation within a wide range of energy excursions in a heating spot. At the same time, due to the pressures inherent in these processes, certain violations have been identified, mainly due to the partial or complete loss of its stability and, as a result, its transition to a more stable form of gas discharge – an electric arc.Objective. The purpose of the paper is to provide stabilization of the burning process of a high-current glow discharge in regimes that are used in precision welding processes at discharge currents of 10 A, and gas pressures of 1.33–13.3 kPa.Methods. Using the methods of the theory of gas discharge physics, electrodynamics and electromagnetism, the main causes of the appearance of external perturbations and instabilities that lead to the emergence of a stable arc discharge on the local sections of the surfaces of the welded parts were determined.Results. It is established that at a constant current of discharge the application of a 5-section anode unit with a traveling electric field increases the region of stable existence of a glow discharge by 1.5–1.7 times in comparison with a similar electrode system with a stationary electric field. The application of this system, when heated by glow discharge, can also increase the energy density in the heating spot by a stable glow discharge by 2.6 to 2.9 times compared with the use of the anode of a continuous section.Conclusions. The stabilization of the power current flare discharge in the conditions of welding heat can be achieved by applying multisection electrode systems, namely by replacing the solid (contour) anode with a sectional one. However, such a system does not exclude the possibility of melting of parts due to the stabilization of the arc discharge on a separate anode section (and the corresponding section of the cathode).

Tracking Propagation Mechanism on the Surface of Polyvinyl-Chloride-Sheathed Flat Cord based on Electric Field Analysis and Gas Discharge Physics

전기 화재의 주요 원인 중 하나인 트래킹은 전기적 방전에 의한 물리적 현상으로 인식된다. 따라서 트래킹은 전계 해석, 전자생성에 의한 도전성 경로, 기체방전이론을 기반으로 설명되어야 한다. 하지만, 이러한 사항을 반영한 연구 논문은 드물다. 본 논문은 트래킹 진전에서 그들의 영향을 포함한 트래킹 진전 메커니즘을 제안하였다. 그 메커니즘의 제안을 위해, 트래킹 실험, 탄화진전 모델에 대한 전계해석, 연면방전 이론을 적용한 트래킹 진전과정에 대한 설명이 수행되었다. 트래킹 모의실험으로부터, 코로나 방전에서 트래킹 파괴까지 트래킹 진전의 각 단계에서 전류파형이 측정되었다. 전계해석은 탄화의 발생과 진전과정동안 건조대 표면의 전계와 전자생성을 위한 고전계 영역을 파악 하기 위해 수행되었다. 본 논문에서 제안된 트래킹 메커니즘은 코로나 방전에 의한 전자사태, 양이온의 축적, 전자사 태의 확장, 2차 전자사태, 스트리머, 도전성 경로에 의한 트래킹 파괴의 6단계로 구성된다. 트래킹 모의실험에서 측정된 펄스성 전류파형은 제안된 트래킹 메커니즘에 의해 설명될 수 있었다. 본 연구 결과는 화재의 원인인 트래킹을 검출하고, 내트래킹성을 높이는 데 필요한 기술 자료가 될 것이다.Tracking, which is one of the main causes of electrical fires, is perceived as a physical phenomenon of electrical discharge. Hence tracking should be explained based on electric field analysis, conduction path by electron generation, and gas discharge physics. However, few papers have considered these details. This paper proposes a tracking mechanism including their effects on tracking progress. In order to prove this mechanism, a tracking experiment, an electric field analysis for the carbonization evolution model, and an explanation of the tracking process by gas discharge physics were conducted. From the tracking experiment, the current waveforms were measured at each stage of the tracking progress from corona discharge to tracking breakdown. The electric field analysis was carried out in order to determine the electric field on the surface of a dry-band and the high electric field region for electron generation during the generation and progress of carbonization. In this paper, the proposed tracking mechanism consisted of six stages including electron avalanche by corona discharge, accumulation of positive ions, expansion of electron avalanche, secondary electron emission avalanche, streamer, and tracking by conductive path. The pulse current waveforms measured in the tracking experiment can be explained by the proposed tracking mechanism. The results of this study will be used as the technical data to detect tracking phenomenon, which is the cause of electric fire, and to improve the proof tracking index.

XVII International Workshop on Magneto-Plasma Aerodynamics

We are proud to present the Proceedings of 17th International Workshop for Magneto-Plasma Aerodynamics (The Workshop) which was held in Moscow on April 17 – 19, 2018 at Joint Institute for High Temperatures of Russian Academy of Sciences (JIHT). The Workshop was organized by JIHT under Scientific Council for Direct Energy Conversion, Scientific Council for Fluid Mechanics and Scientific Council for Low Temperature Plasma Physics of Russian Academy of Sciences. The Workshop was sponsored by Russian Foundation for Basic Research (RFBR).As in previous years, the objective of the 17th Workshop was to provide forum for presentation and discussion of recent progress in science and technology in magneto-plasma aerodynamics. The results of analytical and experimental studies of MHD energy conversion, physics of gas discharge, physics of shock waves, plasma assisted ignition and combustion, physical gas dynamics of high-speed airflows and their applications were discussed at the meeting.The Workshop was attended by more than 70 registered participants from Russia and United States, 53 oral presentation and 15 posters were presented. There was plenary section and several profiled sections: shock waves, electrical discharges, plasma assisted combustion, plasma aerodynamics, MHD flow control and related problems.This year is special for us because this is the first time when we publish our Proceedings in Journal of Physics: Conference Series and we are immensely grateful to IOP Publishing for cooperation. Any registered participant who presented an oral or poster presentation in our Workshop could submit a paper for the proceedings. A total of 32 original papers were submitted, of which 27 were eventually accepted for publication after reviewing process.Valentin Bityurin, PhD, DS, chairman and program committee headAnastasia Dobrovolskaya, organizing committee