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Plasma Science and Technology 2022年第5期24卷 75-79页

作者： wangwen XU Zhanghu HU Dexuan HUI younian wang School of Physics Dalian University of TechnologyDalian 116024People's Republic of China

The study of the interaction between ion beam and plasma is very important to the areas of inertial fusion energy and high energy density physics. With detailed one-dimensional electromagnetic particle-in-cell simulations, we investigate here the interaction of a laseraccelerated proton beam assuming an ideal monoenergetic beam with a gas-discharge *** the saturation stage of the two-stream instability excited by the proton beam, significant high energy electrons are observed, with maximum energy approaching 2 MeV, and a new twostream instability occurs between the high energy electrons and background electrons. The trajectories of plasma electrons are studied, showing the process of electron trapping and detrapping from the wakefield.

关键词： electron beam proton beam two-stream instability particle-in-cell simulation

Simulations of standing wave effect,stop band effect,and skin effect in large-area very high frequency symmetric capacitive discharges

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Plasma Science and Technology 2021年第3期23卷 82-92页

作者： Jiankai LIU Yuru ZHANG Kai ZHAO Deqi WEN younian wang Key Laboratory of Materials Modification by Laser lonand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024People's Republic of China Department of Elctrical and Computer Engineering Michigan State UniversityEast LansingMI 48824United States of America

In this paper,Maxwell equations are coupled with a radially localized global model and an analytical sheath model to investigate the electromagnetic effects under various frequencies and electron powers in large-area very high frequency symmetric capacitive argon *** results indicate that both the vacuum wavelength and the sheath width decrease with frequency,leading to the reduced surface *** a result,the standing wave effect becomes pronounced,causing the fact that the radial profiles of the electron density,radio frequency voltage,and sheath width shift from uniform over center-high to *** the frequency is close to or higher than the series resonance frequency,the surface waves cannot propagate to the radial center because of the significant radial *** to the lack of power deposition near the radial center,the electron density is nearly zero there,*** stop band *** power increases,the higher electron density leads to the decrease of the skin ***,the importance of the skin effect gradually exceeds that of the standing wave effect,giving rise to the transition from the center-high to edge-high electron density *** method proposed in this work could help to predict the plasma distribution under different discharge conditions in a few minutes,which is of significant importance in optimizing the plasma processing.

关键词： electromagnetic effects hybrid model plasma uniformity

Modulation of the plasma uniformity by coil and dielectric window structures in an inductively coupled plasma

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Plasma Science and Technology 2021年第9期23卷 111-122页

作者： Xiaoyan SUN Yuru ZHANG Jing YE younian wang Jianxin HE Textile and Garment Industry of Research In stitute Zhongyuan University of Tech no logyZhengzhou 450007.People's Republic of China 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 School of Textiles Zhongyuan University of Technology.Zhengzhou 450007People's Republic of China

The effects of coil and dielectric window structures on the plasma distribution are examined in a cylindrically symmetric planar inductively coupled plasma(ICP).A two-dimensional(2 D)fluid model is employed to investigate the design issues of ICP source for *** the gradient coil structure is applied at 400 W and 20 mTorr,the ionization rate caused by the power deposition decreases at the reactor center as compared to that in a reactor with a planar coil above the planar dielectric window,and a rather uniform plasma is ***,for the vertical coil geometry,all the coils move to the position of the outermost coil,and the peaks of the power deposition and ionization rate appear at the radial edge of the *** this case,the plasma density is characterized by an edge-high ***,it is observed that the plasma uniformity is improved by increasing the source power under a gas pressure of 20 mTorr and becomes better when the gas pressure increases to 30 mTorr with the source power being fixed at400 W in the gradient coil configuration,but the uniformity of plasma worsens with the rising source power or pressure due to the strong localization in the vertical coil ***,when the discharge is sustained in a reactor with a stepped dielectric window at r=0.135 m,the best plasma uniformity is obtained at 400 W and 20 m Torr because the ionization rate is enhanced at the outermost coil,and the dielectric window at r=0.135 m blocks the diffusion of plasma towards the *** addition,higher source power and lower gas pressure produce more uniform plasma for the designs with a stepped window near the symmetry *** the dielectric window is stepped at r=0.135 m,the non-uniformity of plasma initially decreases and then increases with the increase in source power or gas *** the dielectric window is stepped at the radial edge of the chamber,the plasma uniformity is improved by increasing the source power and gas pressure due t

关键词： fluid simulation gradient coil vertical coil stepped dielectric window plasma uniformity

Experimental investigation of the electromagnetic effect and improvement of the plasma radial uniformity in a large-area,very-high frequency capacitive argon discharge

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Plasma Science and Technology 2021年第5期23卷 66-74页

作者： Daoman HAN Zixuan SU Kai ZHAO Yongxin LIU Fei GAO younian wang Lab of Advanced Space Propulsion and Beijing Engineering Research Center of Efficient and Green Aerospace Propulsion Technology Beijing Institute of Control EngineeringBeijing 100190People’s Republic of China Key Laboratory of Materials Modification by Laser Ionand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024People’s Republic of China

We performed an experimental investigation on the electromagnetic effect and the plasma radial uniformity in a larger-area, cylindrical capacitively coupled plasma reactor. By utilizing a floating hairpin probe, dependences of the plasma radial density on the driving frequency and the radio-frequency power over a wide pressure range of 5-40 Pa were presented. At a relatively low frequency(LF, e.g. 27 MHz), an evident peak generally appears near the electrode edge for all pressures investigated here due to the edge field effect, while at a very high frequency(VHF, e.g.60 or 100 MHz), the plasma density shows a sharp peak at the discharge center at lower pressures, indicating a strong standing wave effect. As the RF power increases, the center-peak structure of plasma density becomes more evident. With increasing the pressure, the standing wave effect is gradually overwhelmed by the ‘stop band’ effect, resulting in a transition in the plasma density profile from a central peak to an edge peak. To improve the plasma radial uniformity, a LF source is introduced into the VHF plasma by balancing the standing wave effect with the edge effect. A much better plasma uniformity can be obtained if one chooses appropriate LF powers, pressures and other corresponding discharge parameters.

关键词： electromagnetic effect plasma radial uniformity very-high-frequency capacitively coupled plasmas

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全自动影像匹配

测绘通报 1999年第4期 41-42页

作者： younian wang 郭革新

影像匹配是指从数字影像上识别相关影像。它是计算机视觉和数字摄影测量中的一个基本问题。本文介绍了结构影像匹配法，它不仅要利用影像灰度值和影像特征，而且要利用它们之间的相互关系。这种方法的目的是在不需要知道数字影像的任何... 详细信息

影像匹配是指从数字影像上识别相关影像。它是计算机视觉和数字摄影测量中的一个基本问题。本文介绍了结构影像匹配法，它不仅要利用影像灰度值和影像特征，而且要利用它们之间的相互关系。这种方法的目的是在不需要知道数字影像的任何先验信息的情况下，对相关特征进行全自动匹配。这种方法的适用性已在非测量影像上得到验证。

关键词：数字摄影测量影像匹配全自动化误差

双频容性耦合CF_4等离子体放电的二维混合模拟

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强激光与粒子束 2013年第9期25卷 2297-2302页

作者：王帅徐翔王友年东北大学理学院沈阳110891 大连理工大学物理与光电工程学院辽宁大连116024

研究了等离子体反应装置内的等离子体密度、粒子能量与角度分布等参量在装置径向与轴向上的分布特性。在研究过程中应用二维混合模型对CF4气体放电进行模拟。计算结果显示:在电极表面与侧壁附近的鞘层区特性有明显的区别。由于装置侧壁... 详细信息

研究了等离子体反应装置内的等离子体密度、粒子能量与角度分布等参量在装置径向与轴向上的分布特性。在研究过程中应用二维混合模型对CF4气体放电进行模拟。计算结果显示:在电极表面与侧壁附近的鞘层区特性有明显的区别。由于装置侧壁处受电源产生的射频电场的影响较小,侧壁处的鞘层主要由双极扩散机制形成,其产生的径向电场强度较弱,鞘层厚度也较薄。而在电极附近,由于受到射频电场的影响,鞘层的厚度显著增加,指向电极方向的轴向电场强度也远大于指向侧壁方向的径向电场强度。在电极区域内,离子通量分布均匀;在电极边缘与侧壁的间隙内,因电场强度减小,离子通量则发生迅速衰减。在射频电极覆盖的范围内离子能量分布大体上保持不变,电极与侧壁的交界处,由于受到侧壁处径向电场的影响,离子能量分布略有不同。在放电装置的中心区域,入射到电极上的离子角度分布基本保持一致,而在电极边界与装置侧壁的交界处,由于径向电场的影响,离子的垂直入射角增加,以大角度轰击电极的离子数量也显著增加。

关键词：双频等离子体混合模拟离子能量分布离子角度分布

Review of stopping power and Coulomb explosion for molecular ion in plasmas

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Matter and Radiation at Extremes 2018年第2期3卷 67-77页

作者： Guiqiu wang He Yi Yujiao Li Yaochuan wang Dajun Liu Fei Gao Wei Liu Jieru Ren Xing wang Yongtao Zhao younian wang College of Science Dalian Maritime UniversityDalian 116026China School of Physics and Optoelectronic Technology Dalian University of TechnologyDalian 116024China School of Science Xi'an Jiaotong UniversityXi'an 710049China

We summarize our theoretical studies for stopping power of energetic heavy ion,diatomic molecular ions and small clusters penetrating through *** a relevant research field for the heavy ion inertial confinement fusion(HICF),we lay the emphasis on the dynamic po-larization and correlation effects of the constituent ion within the molecular ion and cluster for stopping power in order to disclose the role of the vicinage effect on the Coulomb explosion and energy deposition of molecules and clusters in *** the other hand,as a promising scheme for ICF,both a strong laser field and an intense ion beam are used to irradiate a plasma *** the influence of a strong laser field on stopping power is *** discussed a large range of laser and plasma parameters on the coulomb explosion and stopping power for correlated-ion cluster and C 60 ***,in order to indicate the effects of different cluster types and sizes on the stopping power,a comparison is made for hydrogen and carbon *** addition,the deflection of molecular axis for diatomic molecules during the Coulomb explosion is also given for the cases both in the presence of a laser field and laser ***,a future experimental scheme is put forward to measure molecular ion stopping power in plasmas in Xi’an Jiaotong University of China.

关键词： Molecules Stopping power Coulomb explosion Vicinage effect Laser

Influence of the low-frequency source parameters on the plasma characteristics in a dual frequency capacitively coupled plasma reactor:Two dimensional simulations

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Progress in Natural Science:Materials International 2009年第6期19卷 677-684页

作者： Xiang Xu, Hao Ge, Shuai wang, Zhongling Dai, younian wang , Aimin Zhu State Key Lab of Materials Modification by Electron, Ion and Laser Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023, China State Key Lab of Materials Modification by Electron Ion and Laser Beams School of Physics and Optoelectronic Technology Dalian University of Technology Dalian 116023 China

A two-dimensional (2D) fluid model is presented to study the discharge of argon in a dual frequency capacitively coupled plasma (CCP) reactor. We are interested in the influence of low-frequency (LF) source parameters such as applied voltage amplitudes and low frequencies on the plasma characteristics. In this paper, the high frequency is set to 60 MHz with voltage 50 V. The simulations were carried out for low frequencies of 1, 2 and 6 MHz with LF voltage 100 V, and for LF voltages of 60, 90 and 120 V with low frequency 2 MHz. The results of 2D distributions of electric field and ion density, the ion flux impinging on the substrate and the ion energy on the powered electrode are shown. As the low frequency increases, two sources become from uncoupling to coupling. When two sources are uncoupling, the increase in LF has little impact on the plasma characteristics, but when two sources are coupling, the increase in LF decreases the uniformities of ion density and ion flux noticeably. It is also found that with the increase in LF voltage, the uniformities in the radial direction of ion density distribution and ion flux at the powered electrode decreases significantly, and the energy of ions bombarding on the powered electrode increases significantly.

关键词： Dual frequency Capacitively coupled plasma Fluid simulation

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植物杀螨活性物质研究进展

林业科学 2010年第6期46卷 118-127页

作者：王有年北京农学院农业部都市农业(北方)重点开放实验室农业应用新技术北京市重点实验室北京102206

综述近年来菊科、楝科、豆科、瑞香科、藜科、木樨科、唇形花科、伞形花科、蒺藜科以及木本植物的核桃、银杏等70多种植物杀螨作用的研究进展,总结国内外植物源杀螨活性物质的开发利用情况,分析当前植物源杀螨活性物质研究和开发利用中... 详细信息

综述近年来菊科、楝科、豆科、瑞香科、藜科、木樨科、唇形花科、伞形花科、蒺藜科以及木本植物的核桃、银杏等70多种植物杀螨作用的研究进展,总结国内外植物源杀螨活性物质的开发利用情况,分析当前植物源杀螨活性物质研究和开发利用中存在的主要问题,指出在当前杀螨植物的研究上,分离植物中的杀螨活性成分并解析杀螨活性成分的分子结构和阐明植物杀螨活性成分的杀螨机制应该是当前研究的主要方向,并提出具有针对性的研究策略和解决方法,展望植物源杀螨活性物质研究和开发利用的前景和发展方向。

关键词：植物杀螨活性物质开发利用前景展望

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低能高束流氩离子源的结构及性能

核技术 2006年第10期29卷 730-733页

作者：任春生牟宗信王友年大连理工大学三束材料改性国家重点实验室大连116023

离子源技术是等离子体研究中的一项重要内容,而低能大束流源则是离子源技术研究中的一个重要方向,因为这样的源在离子束刻蚀、离子束溅射镀膜以及荷能粒子与物质相互作用方面都有广泛的应用;本文采用空心阴极空心阳极结构,用热阴极电子... 详细信息

离子源技术是等离子体研究中的一项重要内容,而低能大束流源则是离子源技术研究中的一个重要方向,因为这样的源在离子束刻蚀、离子束溅射镀膜以及荷能粒子与物质相互作用方面都有广泛的应用;本文采用空心阴极空心阳极结构,用热阴极电子发射弧放电驱动并用磁场约束产生等离子体,用曲面发射引出离子束,研制成了氩气放电溅射离子源;研究了灯丝加热电流、弧压对弧流的影响和弧流与工作气体压力对离子束引出的影响规律。离子源的引出电压在0—4.0kV之间连续可调,最大引出束流为100mA,束斑面积为φ6.0cm,以Ti为溅射靶时的最大溅射沉积率为0.45nm/s,离子源可连续工作160h。

关键词：氩离子源空心阴极空心阳极磁场离子源性能溅射沉积