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Development of Zeff diagnostic system on the Globus-M（M2） tokamak and the first experimental results

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Plasma Science and Technology 2019年第10期21卷 33-39页

作者： E A TUKHMENEVA S yu.TOLSTYAKOV G S KURSKIEV V K GUSEV V B MINAEV yu.V petrov N V SAKHAROV A yu.TELNOVA N N BAKHAREV P B SHEGOLEV E O KISELEV Ioffe Institute

Studying the behavior of effective ion charge Zeff, which indicates the degree of pollution of plasma and can provide valuable information about many processes taking place in plasma, mechanisms of the releasing impurities, transport, etc is of great interest. This paper describes the development of the Zeff diagnostic system for the Globus-M2 tokamak. The effective ion charge is determined on the basis of measurements of the bremsstrahlung intensity and Thomson scattering data-Te and ne profiles. The results of the first Zeff measurements obtained for several discharges on the Globus-M tokamak are presented in this paper. The results have been validated by simulation using the ASTRA transport code for the same discharges, and it has demonstrated a good agreement with the experimental results.

关键词： tokamak effective ion charge magnetic confinement

Influence of the safety factor profile on the particle and heat transport in the Globus-M spherical tokamak

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Plasma Science and Technology 2019年第11期21卷 1-6页

作者： A yu.TELNOVA G S KURSKIEV E O KISELEV N N BAKHAREV V K GUSEV N A KHROMOV S yu.MEDVEDEV V B MIINAEV I V MIROSHNIKOV M I PATROV yu.V petrov N V SAKHAROV A D SLADKOMEDOVA P B SHCHEGOLEV V V SOLOKHA V A TOKAREV S yu.TOLSTYAKOV E A TUKHMENEVA Ioffe Institute Saint-Petersburg 194021Russia Keldysh Institute Russian Academy of SciencesMoscow 125047Russia NRC'Kurchatov Institute’ Moscow 123098Russia

The advanced tokamak scenario is a promising operation scenario for ITER and fusion neutron *** this scenario the minimum value of the safety factor in the center of the plasma exceeds *** the compact spherical tokamak Globus-M,the formation of such conditions is possible with neutral beam injection at the current ramp-up *** to the slower diffusion of current inside the plasma,a zone is formed with reduced heat and particle transport across the magnetic field,which affects the temperature and density profiles of the *** leads to the peaked density profile formation and improvement of the energy confinement *** achieve a high fraction of the bootstrap current,it is necessary to increase the plasma *** the same time,the maximum allowable pressure is limited to the normalized beta limit.

关键词： advanced tokamak mode transport analysis internal transport barriers

SnO_(2)-ZnO nanocomposite thin films:The influence of structure,composition and crystallinity on optical and electrophysical properties

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Journal of Advanced Dielectrics 2021年第5期11卷 25-32页

作者： E.M.Bayan V.V.petrov M.G.Volkova V.yu.Storozhenko A.V.Chernyshev Faculty of Chemistry Southern Federal University Rostov-on-DonRussia Institute of Nanotechnologies Electronicsand Equipment Engineering Southern Federal UniversityTaganrogRussia Research Institute of Physical and Organic Chemistr Southern Federal University Rostov-on-DonRussia

SnO_(2)-ZnO thin films consisting of nanoscale crystallites were obtained on glass and silicon substrates by solid-phase low-temperature *** synthesized materials were studied by XRD and SEM methods,electrophysical and optical properties were evaluated,as well as the band gap was *** was shown that regardless of the phase composition all films were optically transparent in the visible range(310-1000 nm).The nanocrystallites’minimum size,the highest activation energy of the conductivity and the smallest band gap calculated for indirect transitions were shown for a thin film 50SnO_(2)-*** was assumed that the band gap decreasing might be attributed to the existence of surface electric fields with a strength higher than 4×10^(5)V/cm.

关键词： Zinc tin oxide crystal structure optical property thin films semiconductors nanocomposite

Direct amplification of femtosecond optical vortices in a single-crystal fiber

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Photonics Research 2024年第1期12卷 27-32页

作者： CHANGSHENG ZHENG TIANYI DU LEI ZHU ZHANXIN WANG KANGZHEN TIAN YONGGUANG ZHAO ZHIYONG YANG HAOHAI yu.VALENTIN petrov Jiangsu Key Laboratory of Advanced Laser Materials and Devices School of Physics and Electronic EngineeringJiangsu Normal UniversityXuzhou 221116China State Key Laboratory of Crystal Materials and Institute of Crystal Materials Shandong UniversityJinan 250100China Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy 12489 BerlinGermany

Spatially twisted light with femtosecond temporal structure is of particular interest in strong-field physics and light–matter ***,present femtosecond vortex sources exhibit limited power handling capabilities,and their amplification remains an ongoing challenge particularly for high-order orbital angular momentum(OAM)states due to several inherent technical ***,we exploit a straightforward approach to directly amplify a femtosecond optical vortex(FOV,OAM=-8?)by using a two-stage single-crystal fiber(SCF)amplifier system without pulse stretching and compression in the time domain,delivering 23-W,163-fs pulses at a repetition rate of1 *** spatial and temporal features are well-conserved during the amplification,as well as the high modal purity(>96%).The results indicate that the multi-stage SCF amplifier system is particularly suited for direct amplification of high-order *** generated high-power femtosecond OAM laser beams are expected to help reveal complex physical phenomena in light–matter interactions and pave the way for practical applications in attoscience,laser plasma acceleration,and high-dimension micromachining.

关键词： fiber amplifier crystal

Chirping instabilities produced by a runaway electron beam at a spherical tokamak

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Plasma Science and Technology 2023年第7期25卷 19-24页

作者： I M BALACHENKOV N N BAKHAREV V K GUSEV M V ILIASOVA E M KHILKEVICH P S KORENEV A E KONKOV V B MINAEV yu.V MITRIZHKIN M I PATROV yu.V petrov N V SAKHAROV A E SHEVELEV O M SKREKEL Ioffe Institute Saint-Petersburg 194021Russia Lomonosov Moscow State University Moscow 119991Russia

Two different types of MHD instabilities with rapidly chirping frequency were found to arise in the Globus-M2 spherical tokamak in substantially different frequency *** first type arises at frequencies of an order of 1 MHz in ohmic plasmas at relatively low density(n_(e))<2×10^(19) m^(-3) in a wide range of toroidal magnetic fields and plasma *** type of instability was identified as compressional Alfven waves,driven by electrons,accelerated during a sawtooth *** was found that the mode frequency is sweeping in time,according to the Berk-Breizman hole-clump nonlinear chirping *** second type of wave arises in a specific single-swing regime of the central solenoid current with a very narrow plasma column,when the plasma tends to decay at extremely low density(n_(e))<2×10^(18) m^(-3) and,in fact,is an instability of the runaway electron *** exited modes cover the whole observed frequency range and are divided into several(two or three)frequency regions:approximately 0-30 MHz,60-120 MHz and sometimes 30-60 *** of the branches was also *** chirps are more rapid than for 1 MHz Alfven instability and follow an exponential *** paper,to our knowledge,is the first report of frequency chirping instabilities excited by accelerated electrons at a spherical tokamak.

关键词： Alfvén waves chirping instability spherical tokamak runaway electrons

Magnetoelectric gradient structures: Properties and applications

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Journal of Advanced Dielectrics 2022年第4期12卷 24-29页

作者： A.O.Nikitin V.A.Kiselev V.A.Misilin yu.V.Kiliba R.V.petrov Institute of Electronic and Informative Systems Novgorod State UniversityNo.41B.St.Petersburgskaya Str.Veliky Novgorod 173003Russia

This paper is devoted to a comprehensive study on a new type of microwave structures named magnetoelectric(ME)gradient *** structures are studied in this paper to understand the possibilities and application principles in feasible *** structure under study was calculated at different values of the applied electric field and different values of the relative per-mittivity of the artificial dielectric *** layered multiferroic structure in inhomogeneous electric and magnetic fields was calculated on the basis of the previously proposed mathematical *** eigenwaves spectrum for several considered cases was the result of the performed *** concept of using ME gradient structures in the design of electronically controlled microwave devices is formed on the basis of the results of a numerical *** of this type will preferably be used in electronically controlled devices for the directional transmission of microwave signals,as it was shown in the theoretical part of the paper.

关键词： Composite structures multiferroics magnetoelectric gradient structures artificial dielectric eigenwave spectrum

EFFICIENT AND ACCURATE CHEBYSHEV DUAL-petrov-G ALERKIN METHODS FOR ODD-ORDER DIFFERENTIAL EQUATIONS

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Journal of Computational Mathematics 2021年第1期39卷 43-62页

作者： Xuhong yu.Lusha Jin Zhongqing Wang School of Science University of Shanghai for Science and TechnologyShanghai 200093China

Efficient and accurate Chebyshev dual-petrov-Galerkin methods for solving first-order equation,third-order equation,third-order KdV equation and fifth-order Kawahara equa-tion are *** Sobolev bi-orthogonal basis functions are constructed which lead to the diagonalization of discrete ***,both the exact solutions and the approximate solutions are expanded as an infinite and truncated Fourier-like series,*** experiments illustrate the effectiveness of the suggested approaches.

关键词： Chebyshev dual-petrov-Galerkin method Sobolev bi-orthogonal polynomials Odd-order differential equations Numerical results.

Upper Hybrid Resonance RADAR Scattering Diagnostics of Small Scale Turbulence in FT-1 Tokamak

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中国核科技报告 1999年第S4期 384-384页

作者： A.D.Gurchenko,E.Z.Gusakov,M.M.Larionov,K.M.Novik,yu.V.petrov,A.N.Saveliev,V.L.Selenin,A.yu.Stepanov Ioffe Physico-Technical Institute Politekhnicheskaya 26 194021 St.Petersburg Russia Ioffe Physico-Technical Institute Politekhnicheskaya 26 194021 St.Petersburg Russia Ioffe Physico-Technical Institute Politekhnicheskaya 26 194021 St.Petersburg Russia Ioffe Physico-Technical Institute Politekhnicheskaya 26 194021 St.Petersburg Russia Ioffe Physico-Technical Institute Politekhnicheskaya 26 194021 St.Petersburg Russia Ioffe Physico-Technical Institute Politekhnicheskaya 26 194021 St.Petersburg Russia Ioffe Physico-Technical Institute Politekhnicheskaya 26 194021 St.Petersburg Russia Ioffe Physico-Technical Institute Politekhnicheskaya 26 194021 St.Petersburg Russia

The new diagnostic technique, utilizing RADAR microwave scattering in the Upper Hybrid Resonance (UHR) has been developed and applied for study of spontaneous magnetic field and density turbulence in the FT-1 tokamak.... 详细信息

关键词： Upper Hybrid Resonance RADAR Scattering Diagnostics of Small Scale Turbulence in FT-1 Tokamak FT

Investigation of electrophysical, photo- and gas-sensitive properties of ZnO–SnO_(2) sol–gel fflms

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Journal of Advanced Dielectrics 2024年第1期14卷 42-50页

作者： Irina A.Gulyaeva Alexandra P.Ivanisheva Maria G.Volkova Victoria yu.Storozhenko Soslan A.Khubezhov Ekaterina M.Bayan Victor V.petrov Research and Education Centre“Microsystem Technics and Multisensory Monitoring Systems”Southern Federal University Russia Department of Chemistry Southern Federal UniversityRussia Department of Physics North-Ossetian State University362025 VladikavkazRussia Department of Physics and Engineering ITMO University191002 PetersburgRussia

Thin nanocomposite fflms based on tin dioxide with a low content of zinc oxide(0.5–5 mol.%)were obtained by the sol–gel *** synthesized fflms are 300–600 nm thick and contains pore sizes of 19–29 *** resulting ZnO–SnO_(2) fflms were comprehensively studied by atomic force and Kelvin probe force microscopy,X-ray diffraction,scanning electron microscopy,and high-resolution X-ray photoelectron spectroscopy *** photoconductivity parameters on exposure to light with a wavelength of 470 nm were also *** study of the photosensitivity kinetics of ZnO–SnO_(2) fflms showed that the fflm with the Zn:Sn ratio equal to 0.5:99.5 has the minimum value of the charge carrier generation time *** of the activation energy of the conductivity,potential barrier,and surface potential of ZnO–SnO_(2) fflms showed that these parameters have maxima at ZnO concentrations of 0.5 mol.%and 1 mol.%.Films with 1 mol.%ZnO exhibit high response values when exposed to 5–50 ppm of nitrogen dioxide at operating temperatures of 200℃ and 250℃.

关键词： Sol–gel method,ZnO–SnO_(2) films gas-sensitive properties surface potential potential barrier conduction activation energy