检索结果-南通市图书馆

Discharge mode and particle transport in radio frequency capacitively coupled Ar/O_(2)plasma discharges

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第9期33卷 451-460页

作者： Zhuo-Yao Gao Wan Dong Chong-Biao Tian Xing-Zhao Jiang Zhong-Ling Dai Yuan-Hong Song key laboratory of materials modification by Laser Ionand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024China

Simulations are conducted on capacitively coupled Ar/O_(2)mixed gas discharges employing a one-dimensional fluid coupled with an electron Monte Carlo(MC)*** research explores the impact of different O_(2)ratio and pressures on the discharge characteristics of Ar/O_(2)*** a fixed Ar/O_(2)gas ratio,with the increasing pressure,higher ion densities,as well as a slight increase in electron density in the bulk region can be *** discharge remains dominated by the drift-ambipolar(DA)mode,and the flux of O(3P)at the electrode increases with the increasing pressure due to higher background gas density,while the fluxes of O(1D)and Ardecrease due to the pronounced loss *** the increasing proportion of O_(2),a change in the dominant discharge mode from a mode to DA mode can be detected,and the O_(2)-associated charged particle densities are significantly ***,Ar+density shows a trend of increasing and then decreasing,while for neutral fluxes at the electrode,Arflux decreases,and O(3P)flux increases with the reduced Ar gas proportion,while trends in O(1D)flux show slight *** evolution of the densities of the charged particle and the neutral fluxes under different discharge parameters are discussed in detail using the ionization characteristics as well as the transport ***,more comprehensive understanding of Ar/O_(2)discharge characteristics in this work will provide a valuable reference for the industry.

关键词： Ar/O_(2) mixed gas discharges electron dynamics transport of charged and neutral particles

Experimental studies of H_(2)/Ar plasma in a cylindrical inductive discharge with an expansion region

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第10期33卷 321-330页

作者： Shi-Bo Li Si-Yu Xing Fei Gao You-Nian Wang key laboratory of materials modification by Laser Ionand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024China

The electrical parameters of H_(2)/Ar plasma in a cylindrical inductive discharge with an expansion region are investigated by a Langmuir probe,where Ar fractions range from 0%to 100%.The influence of gas composition and pressure on electron density,the effective electron temperature and the electron energy probability functions(EEPFs)at different spatial positions are *** driver region,with the introduction of a small amount of Ar at 0.3 Pa,there is a rapid increase in electron density accompanied by a decrease in the effective electron ***,the shape of the EEPF transitions from a three-temperature distribution to a bi-Maxwellian distribution due to an increase in electron-electron ***,this phenomenon resulting from the changes in gas composition vanishes at 5 Pa due to the prior depletion of energetic electrons caused by the increase in pressure during hydrogen *** EEPFs for the total energy in expansion region is coincident to these in the driver region at 0.3 Pa,as do the patterns of electron density variation between these two regions for differing Ar *** 5 Pa,as the discharge transitions from H_(2)to Ar,the EEPFs evolved from a bi-Maxwellian distribution with pronounced low energy electrons to a Maxwellian distribution in expansion *** evolve may be attributed to a reduction in molecular vibrational excitation reactions of electrons during transport and the transition from localized electron dynamics in hydrogen discharge to non-localized electron dynamics in argon *** order to validate the experimental results,we use the COMSOL simulation software to calculate electrical parameters under the same *** evolution and spatial distribution of the electrical parameters of the simulation results agree well with the trend of the experimental results.

关键词： inductively coupled plasma transmission and distribution energy distribution functions

Abnormal transition of the electron energy distribution with excitation of the second harmonic in low-pressure radio-frequency capacitively coupled plasmas

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2024年第8期26卷 58-63页

作者：余乐怡陆文琪张丽娜 key laboratory of materials modification by Laser Ionand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024People’s Republic of China

The self-excited second harmonic in radio-frequency capacitively coupled plasma was significantly enhanced by adjusting the external variable *** a lower pressure of 3 Pa,the excitation of the second harmonic caused an abnormal transition of the electron energy probability function,resulting in abrupt changes in the electron density and *** changes in the electron energy probability function as well as the electron density and temperature were not observed at the higher pressure of 16 Pa under similar harmonic *** phenomena are related to the influence of the second harmonic on stochastic heating,which is determined by both amplitude and the relative phase of the *** results suggest that the self-excited high-order harmonics must be considered in practical applications of lowpressure radio-frequency capacitively coupled plasmas.

关键词： radio-frequency capacitively coupled plasma harmonics the electron energy probability function

Defect-modulated synthesis and optoelectronic properties in chemical vapor deposited CsPbBr_(3) microplates

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第5期17卷 4610-4615页

作者： Yanan Bao Hengshan Wang Meiqi An Huayi Tang Jing Li Jianliang Li Conghui Tan Yingmin Luo Jiao Xu Yiming Yang School of Microelectronics Dalian University of TechnologyDalian 116024China key laboratory of materials modification by Laser Ionand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024China

The remarkable optoelectronic features of halide perovskite promote their potential applications in semiconductor devices beyond solar cells,which require high-quality single crystals with controlled defect ***,we investigated the synthesis mechanism of chemical vapor deposited single-crystalline all-inorganic perovskite microplates(MPs),and reported a defect-modulated photocurrent which is closely related to the growth sequence of the *** MP synthesis initiates from island-like nano-disks,and subsequently transits to a layer-by-layer fashion,resulting in a defect-rich area at the center of the *** elevated temperatures,these central defects may be thermally activated and become highly mobile,leading to photoluminescence quenching and degression of local and overall optoelectronic attributes,as evidenced by the spatial resolved optical and electrical scanning probe ***,this work shines light on the formation,proliferation and dynamics of defects in perovskites,and offers guidance for preparation of high-quality perovskites micro-crystals for functional semiconductor devices with high temperature stability.

关键词： halide perovskites nanomaterials optoelectronics scanning photocurrent microscope chemical vapor deposition

Power transfer efficiency in an air-breathing radio frequency ion thruster

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第7期33卷 430-438页

作者：黄高煌李宏高飞王友年 key laboratory of materials modification by Laser Ionand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024China College of Physical Science and Technology Dalian UniversityDalian 116622China

Due to a series of challenges such as low-orbit maintenance of satellites, the air-breathing electric propulsion has got widespread attention. Commonly, the radio frequency ion thruster is favored by low-orbit missions due to its high specific impulse and efficiency. In this paper, the power transfer efficiency of the radio frequency ion thruster with different gas compositions is studied experimentally, which is obtained by measuring the radio frequency power and current of the antenna coil with and without discharge operation. The results show that increasing the turns of antenna coils can effectively improve the radio frequency power transfer efficiency, which is due to the improvement of Q factor. In pure N_2 discharge,with the increase of radio frequency power, the radio frequency power transfer efficiency first rises rapidly and then exhibits a less steep increasing trend. The radio frequency power transfer efficiency increases with the increase of gas pressure at relatively high power, while declines rapidly at relatively low power. In N_(2)/O_(2) discharge, increasing the N_(2) content at high power can improve the radio frequency power transfer efficiency, but the opposite was observed at low power. In order to give a better understanding of these trends, an analytic solution in limit cases is utilized, and a Langmuir probe was employed to measure the electron density. It is found that the evolution of radio frequency power transfer efficiency can be well explained by the variation of plasma resistance, which is related to the electron density and the effective electron collision frequency.

关键词： radio frequency ion thruster inductively coupled plasma power transfer efficiency analytic solution

Effects of diamagnetic drift on nonlinear interaction between multi-helicity neoclassical tearing modes

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第6期33卷 452-458页

作者：王海源姜帅刘桐魏来栾其斌王正汹 key laboratory of materials modification by Laser Ionand Electron Beams of the Ministry of EducationSchool of PhysicsDalian University of TechnologyDalian 116024China Faculty of Electronic Information and Electrical Engineering Dalian University of TechnologyDalian 116024China

A numerical study of the diamagnetic drift effect on the nonlinear interaction between multi-helicity neoclassical tearing modes(NTMs) is carried out using a set of four-field equations including two-fluid *** results show that,in contrast to the single-fluid case,5/3 NTM cannot be completely suppressed by 3/2 NTM with diamagnetic drift *** modes exhibit oscillation and coexist in the saturated *** better understand the effect of the diamagnetic drift flow on multiple-helicity NTMs,the influence of typical relevant parameters is *** is found that the average saturated magnetic island width increases with increasing bootstrap current fraction f_(b) but decreases with the ion skin depth δ.In addition,as the ratio of parallel to perpendicular transport coefficients χ_(‖)/χ_(⊥) increases,the average saturated magnetic island widths of the 3/2 and 5/3 NTMs *** underlying mechanisms behind these observations are discussed in detail.

关键词： tokamak two-fluid neoclassical tearing modes multi-helicity

Simulation of tungsten impurity transport by DIVIMP under different divertor magnetic configurations on HL-3

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2024年第10期26卷 29-38页

作者： Qingrui ZHOU Yanjie ZHANG Chaofeng SANG Jiaxian LI Guoyao ZHENG Yilin WANG Yihan WU Dezhen WANG key laboratory of materials modification by Laser Ion and Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024People’s Republic of China Southwestern Institute of Physics Chengdu 610041People’s Republic of China

Tungsten(W)accumulation in the core,depending on W generation and transport in the edge region,is a severe issue in fusion *** to standard divertors(SDs),snowflake divertors(SFDs)can effectively suppress the heat flux,while the impact of magnetic configurations on W core accumulation remains *** this study,the kinetic code DIVIMP combined with the SOLPS-ITER code is applied to investigate the effects of divertor magnetic configurations(SD versus SFD)on W accumulation during neon injection in *** is found that the W concentration in the core of the SFD is significantly higher than that of the SD with similar total W erosion *** reasons for this are:(1)W impurities in the core of the SFD mainly originate from the inner divertor,which has a short leg,and the source is close to the divertor entrance and upstream ***,the W ionization source(S_(W0))is much stronger,especially near the divertor entrance.(2)The region overlap of S_(W0)and F_(W,TOT)pointing upstream promote W accumulation in the ***,the influence of W source locations at the inner target on W transport in the SFD is *** impurity in the core is mainly contributed by target erosion in the common flux region(CFR)away from the strike *** is attributed to the fact that the W source at this location enhances the ionization source above the W ion stagnation point,which sequentially increases W ***,the suppression of far SOL inner target erosion can effectively prevent W impurities from accumulating in the core.

关键词： snowflake divertor neon seeding tungsten transport DIVIMP HL-3

Simulation of charge-exchange induced NBI losses on EAST

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2024年第9期26卷 133-147页

作者： Zhanhong LIN Feng WANG Ming XU Chaofeng SANG Chen ZHANG Zhengxiong WANG key laboratory of materials modification by beams of the ministry of education School of PhysicsDalian University of TechnologyDalian 116024People’s Republic of China Institute of Plasma Physics Chinese Academy of SciencesHefei 230031People’s Republic of China

The neutral beam injection is widely adopted in tokamaks as a key heating tool,playing a crucial role in generating burning ***,the loss of beam ions can damage the first wall and reduce the heating efficiency,resulting in failure to maintain steady-state *** this work,the effect of neutral particles in the edge on fast ions generated by NBI in the Experimental Advanced Superconducting Tokamak(EAST)device is studied using the particle tracer code(PTC).The poloidal distribution of neutral particles is calculated by edge plasma simulation code *** this simulation,four beam lines in EAST are considered:co-current tangential(co-tang),co-current perpendicular(co-perp),counter-current tangential(ctr-tang)and counter-current perpendicular(ctr-perp).It is shown that,in the absence of neutral particles,the loss fraction of ctr-injection is considerably higher than that of the *** considering the neutral particles,it is found that the ctr-perp injection demonstrates a significant variation in particles loss fraction(ranging from 18.56%to 25.42%)compared to the other three injection *** terms of the loss fraction induced by neutral particles,ctr-injection exceeds co-injection,and perpendicular configuration exceeds tangential ***,the difference of charge exchange ratios of three different energy(full energy,half energy,one third energy)of the four injections can be attributed to variations in the poloidal trajectories associated with each of these ***,approximately half of fast ions which undergo neutralization directly lose to the first wall while the rest re-enter the bulk plasma and *** for the ctr-tang injection,the reionization ions from the other three injections exhibit effective confinement.

关键词： NBI charge exchange fast ion loss

Hot Compression Behavior and Tensile Property of a Novel Ni-Co-Based Superalloy Prepared by Electron Beam Smelting Layered Solidification Technology

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 283-292页

作者： Yong-Chao Gai Rui Zhang Chuan-Yong Cui Zi-Jian Zhou Yi Tan Yi-Zhou Zhou Xiao-Feng Sun key laboratory of materials modification by Laser Ionand Electron Beams(Ministry of Education)School of Materials Science and EngineeringDalian University of TechnologyDalian116024China Shi-Changxu Innovation Center for Advanced materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

The hot compression behavior and tensile strength after compression of a new Ni-Co-based superalloy produced using electron beam smelting layered(EBSL)solidification technology were *** compression tests were performed at temperatures of 1120℃and 1150℃,with strain rates of 1 s^(-1) and 0.01 s^(-1),reaching a true strain of *** strength was evaluated at room *** results revealed that this EBSL technology accelerates dynamic recrystallization(DRX),without compromising the strength of alloy.A significant correlation between the volume fraction of DRX and the strain rate was observed,with higher fractions at lower strain rates,leading to higher tensile ***,at the same strain rate,the specimens compressed at 1120℃exhibited higher tensile strength due to undissolvedγ′*** solution and aging heat treatment,the alloy maintained high tensile *** results suggested that the EBSL Ni-Co-based superalloy offers excellent prospects for practical applications.

关键词： Ni-Co-based superalloy Hot deformation Electron beam smelting Tensile strength