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Runaway electrons during subnanosecond breakdowns in high-pressure gases

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High voltage 2016年第4期1卷 181-191页

作者： victor F.Tarasenko Mikhail I.Lomaev dmitry v.beloplotov dmitry A.Sorokin Institute of High Current Electronics Siberian Branch Russian Academy of Science2/3 Akademicheskii Ave.Tomsk 634055Russia

The parameters of runaway electrons produced in nanosecond high-voltage discharges in different gases(air,nitrogen,sulphur hexafluoride,krypton,argon,methane,neon,hydrogen,helium)at atmospheric and higher pressure were *** optical analysis was also performed to investigate the ionisation dynamics in diffuse discharges in nitrogen and nitrogen-containing *** breakdown of a point-to-plane gap by nanosecond(≃2 ns)high-voltage(≃200 kv)pulses of negative voltage polarity and gas pressure above 0.1 MPa,a supershort avalanche electron beam(SAEB)was detected by a collector behind the flat *** pressure>0.1 MPa of nitrogen and other gases it is shown that the maximum pressure for SAEB registration decreases with increasing the voltage pulse rise ***,to detect a SAEB at atmospheric and higher gas pressure,one should use voltage pulses with an amplitude of hundred kilovolts and rise time of∼1 ns and *** experimental research in the dynamics of optical radiation from the discharge plasma shows that the breakdown in which runaway electrons are produced develops as an ionisation wave.

关键词： wave. gases fluoride

Diffuse discharges in SF_(6)and mixtures of SF_(6)with H_(2),formed by nanosecond voltage pulses in non-uniform electric field

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High voltage 2018年第4期3卷 316-322页

作者： Alexei N.Panchenko victor F.Tarasenko dmitry v.beloplotov Nikolay A.Panchenko Mikhail I.Lomaev Institute of High Current Electronics Siberian Branch(SB)Russian Academy of Sciences(RAS)Tomsk 634055Russia Faculty of Innovative Technologies National Research Tomsk State UniversityTomsk 634050Russia Department of Photonics and Quantum Electronics National Research Tomsk Polytechnic UniversityTomsk 634050Russia Department of Physics Tomsk State University of Control Systems and RadioelectronicsTomsk 634050Russia

Results of experimental study of nanosecond diffuse discharge in SF_(6)and gas mixtures of SF_(6)with H_(2),D_(2)and C_(2)H_(6)are *** aim of this work is to study parameters of discharge between two extended electrodes with a small radius of curvature in SF_(6)and SF_(6)with *** was shown that diffuse discharge can be formed in SF_(6)at elevated pressure between blade electrodes with length of 30 *** was also confirmed that in a sharply non-uniform electric field a beam of runaway electrons is generated and that the gap breakdown occurs due to ionisation waves which begin on electrodes with small radius of *** action in the infrared spectral region was obtained in SF_(6)-H_(2)(D_(2),C_(2)H_(6))*** laser output up to 110 mJ was easily achieved which corresponds to ultimate intrinsic efficiency(with respect to deposited energy)of 10%.

关键词： breakdown uniform radius

Review of supershort avalanche electron beam during nanosecond-pulse discharges in some gases

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Matter and Radiation at Extremes 2017年第3期2卷 105-116页

作者： victor F.Tarasenko Cheng Zhang Evgenii Kh.Baksht Alexander G.Burachenko Tao Shao dmitry v.beloplotov Mikhail I.Lomaev Ping Yan Andrey v.Kozyrev Natalia S.Semeniuk Laboratory of Optical Radiation of the Institute of High Current Electronics Tomsk 634055Russia National Research Tomsk State University Tomsk 634050Russia National Research Tomsk Polytechnic University Tomsk 634050Russia Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China

Supershort avalanche electron beam(SAEB)plays an important role in nanosecond-pulse *** paper aims at reviewing ex-periments results on characteritics of SAEB and its spectra in different gases in nanosecond-pulse *** the joint experiments were carried in the Institute of High Current Electronics of the Russian Academy of Sciences and the Institute of Electrical Engineering of the Chinese Academy of *** these experiments,the generation of a SAEB in SF 6 in an inhomogeneous electric field was studied on three generators with pulse rise times of 0.3,0.5 and~2 ***,the comparison of SAEB parameters in SF 6 with those obtained in other gases(air,nitrogen,argon,and krypton)is ***,the SAEB spectra in SF 6 and air at pressures of 10 kPa(75 torr),and 0.1 MPa(750 torr)are reviewed and ***,1.5-D theoretical simulation of the supershort pulse of the fast electron beam in a coaxial diode filled with SF 6 at atmospheric pressure is *** simulation was carried out in the framework of hybrid model for discharge and runaway electron *** above research progress can provide better understanding of the investigation into the mechanism of nanosecond-pulse discharges.

关键词： Runaway electrons Supershort avalanche electron beam(SAEB) SF 6 Gas diode High pressure Simulation Hybrid model

Suppressing filamentation instability due to laser beam self-filtering

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High Power Laser Science and Engineering 2024年第3期12卷 51-61页

作者： dmitry Silin Efim Khazanov A.v.Gaponov-Grekhov Institute of Applied Physics of the Russian Academy of Sciences Nizhny NovgorodRussia

The development of small-scale self-focusing in a nonlinear Kerr medium after preliminary self-filtering of a laser beam propagating in free space is studied *** is shown that,under definite conditions,due to self-filtering,filamentation instability(beam splitting into filaments)either occurs at significantly larger values of the B-integral,or does not occur at *** the latter case,there develops the honeycomb instability revealed in this *** instability is the formation of a random honeycomb structure in the beam *** is shown that self-filtering can significantly increase the permissible values of the B-integral,at which the beam quality remains acceptable.

关键词： filamentation instability honeycomb instability self-filtering small-scale self-focusing

Cluster Analysis of the Roma-BZCAT Blazars

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Research in Astronomy and Astrophysics 2024年第5期24卷 117-139页

作者： dmitry O.Kudryavtsev Yulia v.Sotnikova vladislav A.Stolyarov Timur v.Mufakharov valery v.vlasyuk Margarita L.Khabibullina Alexander G.Mikhailov Yulia v.Cherepkova Special Astrophysical Observatory of the Russian Academy of Sciences Nizhny Arkhyz 369167Russia Astrophysics Group Cavendish LaboratoryUniversity of CambridgeCambridge CB3 OHEUK Kazan Federal University 18 Kremlyovskaya StKazan 420008Russia

Based on the collected multiwavelength data, namely in the radio(NvSS, FIRST, RATAN-600), IR(WISE),optical(Pan-STARRS), Uv(GALEX), and X-ray(ROSAT, Swift-XRT) ranges, we have performed a cluster analysis for the blazars of the Roma-BZCAT catalog. Using two machine learning methods, namely a combination of PCA with k-means clustering and Kohonen's self-organizing maps(SOMs), we have constructed an independent classification of the blazars(five classes) and compared the classes with the known Roma-BZCAT classification(FSRQs, BL Lacs, galaxy-dominated BL Lacs, and blazars of an uncertain type) as well as with the high synchrotron peaked(HSP) blazars from the 3HSP catalog and blazars from the TevCat catalog. The obtained groups demonstrate concordance with the BL Lac/FSRQ classification along with a continuous character of the change in the properties. The group of HSP blazars stands out against the overall distribution. We examine the characteristics of the five groups and demonstrate distinctions in their spectral energy distribution shapes. The effectiveness of the clustering technique for objective analysis of multiparametric arrays of experimental data is demonstrated.

关键词： methods data analysis-galaxies active-(galaxies:)BL Lacertae objects general

Interaction of edge dislocations with voids in tungsten

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Tungsten 2024年第3期6卷 633-646页

作者： Arseny Kazakov Rita I.Babicheva Aleksandr Zinovev dmitry Terentyev Kun Zhou Elena A.Korznikova Sergey v.Dmitriev Research Laboratory for Metals and Alloys under Extreme Impacts Ufa University of Science and Technology Institute for Metals Superplasticity Problems of RAS School of Mechanical and Aerospace Engineering Nanyang Technological University Institute for Nuclear Energy Technology Belgian Nuclear Research Center Technological Machines and Equipment Department Ufa State Petroleum Technological University Institute of Mechanical Science Problems of RAS Institute of Molecule and Crystal Physics UFRC of Russian Academy of Sciences

Tungsten is widely used as a material capable of withstanding extreme operating conditions and is one of the candidates for use in fusion and Generation Ⅳ fission *** modelling implemented to solve various material science problems is an indispensable approach for improving material *** work analyzes the interaction of an edge dislocation with a void in single-crystal tungsten with the help of molecular dynamics *** different approaches for studying the dynamics of dislocations in tungsten that differ in boundary conditions are *** interactions of the dislocation and void at different temperatures are investigated,and based on the obtained stress-strain curves,the dislocation obstacle strength for voids having various diameters is *** is shown that when applied to a crystal with small voids,the model with the fixed boundary conditions returns incorrect ***,the influence of the cell size for the model with periodic boundary conditions is analyzed,and the case of a non-central interaction of a dislocation with a void is *** obtained results improve our understanding of the mechanical response of irradiated materials.

关键词： Tungsten Molecular dynamics method Dislocations voids Boundary conditions

Porous Shish-Kebab Structure Prepared from Oriented UHMWPE Films by Processing in Supercritical CO_(2)

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Chinese Journal of Polymer Science 2024年第1期42卷 97-104,I0009页

作者： Sergey A.Lermontov Aleksey v.Maksimkin Nataliya A.Sipyagina Tarek Dayyoub Alena N.Malkova Evgeniy A.Kolesnikov Elena A.Straumal Inna O.Gozhikova Saidkhodzha G.Nematulloev dmitry v.Telyshev Institute of Physiologically Active Compounds of the Russian Academy of Sciences Chernogolovka 142432Russia Institute for Bionic Technologies and Engineering I.M.Sechenov First Moscow State Medical University(Sechenov University)Moscow 19991Russia National University of Science and Technology"MISIS"Moscow 119049 Russia Institute of Biomedical Systems National Research University of Electronic TechnologyZelenogradMoscow 124498Russia

For the first time, a highly crystalline porous shish-kebab structure with a high degree of crystallinity was obtained by using a combination of two methods for the formation of porous polymeric materials. A treatment procedure using supercritical carbon dioxide(sc CO_(2))was carried out for oriented ultrahigh molecular weight polyethylene(UHMWPE) films, which provided special conditions for the crystallization of dissolved UHMWPE macromolecules on the surface of oriented UHMWPE crystals. The prepared porous materials were investigated by scanning electron microscopy(SEM) and differential scanning calorimetry(DSC). The particularity of the obtained porous shish-kebab is the absence of the amorphous phase between lamellar crystals(kebabs). The obtained pores had an oval shape, and they were oriented in the orientation direction of the UHMWPE macromolecules. The pore size ranged from 0.05 μm to 4 μm. Controlling the conditions for the crystallization of the UHMWPE macromolecules using supercritical CO_(2) gives the possibility to control the size of both lamellar disks and pores formed.

关键词： UHMWPE Supercritical CO_(2) Porous shish-kebab structure

Wood anatomy chronologies of Scots pine in the foothills of the Western Sayan(Siberia)

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Journal of Forestry Research 2024年第3期35卷 13-27页

作者： Elena A.Babushkina dmitry R.Dergunov Mikhail S.Zharkov Liliana v.Belokopytova Dina F.Zhirnova Bao Yang Jingjing Liu Xiaomei Peng Eugene A.vaganov Khakass Technical Institute Siberian Federal UniversityAbakan 655017Russia Institute of Ecology and Geography Siberian Federal UniversityKrasnoyarsk 660036Russia Mathematical Methods and IT Department Siberian Federal UniversityKrasnoyarsk 660036Russia Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000People's Republic of China School of Geographic and Oceanographic Sciences Nanjing UniversityNanjing 210093People's Republic of China Department of Dendroecology V.N.Sukachev Institute of ForestSiberian Branch of the Russian Academy of ScienceKrasnoyarsk 660036Russia

Recent methodological advances in quantitative wood anatomy have provided new insights into the climatic responses of radial growth at the scale of cell structure of tree rings. This study considered long-term chronologies of tracheid measurements, indexed by a novel approach to separate their specific climatic responses from signal recorded in cell production(closely reflected in tree-ring width). To fill gaps in understanding the impact of climate on conifer xylem structure, Scots pine(Pinus sylvestris L.)trees > 200 years old were selected within the forest-steppe zone in southern Siberia. Such habitats undergo mild moisture deficits and the resulting climatic regulation of growth processes. Mean and maximum values of cell radial diameter and cell wall thickness were recorded for each tree *** a low level of climatogenic stress, components of cell chronologies independent of cambial activity were separated to obtain significant climatic signals revealing the timing of the specific stages of tracheid differentiation. Cell expansion lasted from mid-April to July and was impacted similarly to tree-ring width(stimulated by precipitation and stressed by heat), maximum cell size formed late June. A switch in the climatic responses of mean anatomical traits indicated transition to latewood in mid-July. Secondary wall deposition lasted until mid-September, suppressed by end of season temperatures. Generally, anatomical climatic responses were modulated by a less dry May and September compared with summer months.

关键词： Quantitative wood anatomy Cell radial size Cell wall thickness Pinus sylvestris Climatic response

浓度梯度掺杂实现BiFeO_(3)薄膜自极化

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无机材料学报 2024年第1期39卷 99-106,I0006,I0007页

作者：戴乐刘洋高轩王书豪宋雅婷唐明猛 dmitry v Karpinsky 刘丽莎汪尧进南京理工大学材料科学与工程学院南京210094 白俄罗斯国家科学院材料科学与应用研究中心白俄罗斯明斯克220072

BiFeO_(3)是一种非常有前途的无铅铁电材料,与大多数传统铁电材料相比,它具有更大的极化和更高的居里温度,为高温应用提供了可能。受到衬底强烈的夹持效应、较大的矫顽场和漏电流的影响,BiFeO_(3)薄膜难以被极化。自极化是解决这一问题... 详细信息

BiFeO_(3)是一种非常有前途的无铅铁电材料,与大多数传统铁电材料相比,它具有更大的极化和更高的居里温度,为高温应用提供了可能。受到衬底强烈的夹持效应、较大的矫顽场和漏电流的影响,BiFeO_(3)薄膜难以被极化。自极化是解决这一问题的可行方法。本研究采用溶胶-凝胶法在Pt(111)/Ti/SiO_(2)/Si衬底上生长了BiFeO_(3)薄膜,向上梯度薄膜(从衬底BiFeO_(3)过渡到薄膜表面Bi_(0.80)Ca_(0.20)FeO_(2.90))以及向下梯度薄膜(从衬底Bi_(0.80)Ca_(0.20)FeO_(2.90)过渡到薄膜表面BiFeO_(3))。通过细致地调控薄膜内部缺陷的定向分布形成内置电场,从而导致薄膜具有自极化特性。压电力显微镜结果表明:在BiFeO_(3)薄膜中,Ca的梯度方向可以调控自极化的方向。此外,类似二极管的单向导通特性验证了薄膜的自极化是由Ca的浓度梯度掺杂导致。X射线光电子能谱结果表明,氧空位的梯度分布导致的内置电场可能是造成自极化现象的原因。本研究为实现铁电薄膜的自极化提供了一种新的策略,并在以自极化的内置电场为驱动,提高光伏或光敏器件性能方面具有潜在的应用前景。

关键词：自极化梯度掺杂铁酸铋薄膜溶胶-凝胶法