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Control of Beam Energy and Flux Ratio in an Ion-Beam-Background Plasma System Produced in a Double Plasma Device

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Plasma Science and Technology 2016年第11期18卷 1076-1080页

作者： wei zian MAJinxiu LI Yuanrui SUN Yan JIANG Zhengqi CAS Key Laboratory of Geospace Environment Department of Modern Physics University of Science and Technology of China Hefei 230026 China Ming Hsieh Department of Electrical Engineering University of Southern California Los Angeles CA90089 USA

Plasmas containing ion beams have various applications both in plasma technology and in fundamental research. The ion beam energy and flux are the two factors characterizing the beam properties. Previous studies have not achieved the independent adjustment of these two parameters. In this paper, an ion-beam-background-plasma system was produced with hotcathode discharge in a double plasma device separated by two adjacent grids, with which the beam energy and flux ratio （the ratio between the beam flux and total ion flux） can be controlled independently. It is shown that the discharge voltage （i.e., voltage across the hot-cathode and anode） and the voltage drop between the two separation grids can be used to effectively control the beam energy while the flux ratio is not affected by these voltages. The flux ratio depends sensitively on hot-filaments heating current whose influence on the beam energy is relatively weak, and thus enabling approximate control of the flux ratio

关键词： ion beam background plasma beam energy flux ratio

Electron sheaths near a positively biased plate subjected to a weak electron beam

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Plasma Science and Technology 2023年第3期25卷 70-77页

作者：刘琦卫子安马锦秀弋开阳陶万李政元 School of Physical Sciences University of Science and Technology of ChinaHefei 230026Peopleʼs Republic of China Department of Plasma Physics and Fusion Engineering University of Science and Technology of ChinaHefei 230026Peopleʼs Republic of China Southwestern Institute of Physics Chengdu 610041Peopleʼs Republic of China

Electron sheaths have previously only been measured near a positively biased small electrode, in which a potential dip was often observed. In this paper, we present an experimental study on the electron sheath near a stainless steel plate in the presence of a weak electron beam. It is shown that the electron beam, though its density is much lower than that of the background plasma, will substantially alter the sheath structure, i.e., it causes the disappearance of the potential dip when the beam energy just exceeds the ionization potential of the neutral gas but later enhances the dip for higher energies. It is also shown that proper biases on the plate and chamber wall are the key to the formation of the electron sheath and the dip. For a fixed plate bias but with different electron beam energy, the measured thickness of the ion-free Child–Langmuir sheath agrees well with that of the theoretical model.

关键词： electron sheath potential dip electron-beam-plasma system

The impact of toroidal mode coupling on high-density discharges in J-TEXT

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Plasma Science and Technology 2024年第12期26卷 1-8页

作者： Peng DENG Wenzhe MAO Zhipeng CHEN Yinan ZHOU Peng SHI Zhoujun YANG Li GAO Tao LAN Jinlin XIE Hong LI zian wei Adi LIU Chu ZHOU weixing DING Wandong LIU Ge ZHUANG School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026People’s Republic of China State Key Laboratory of Advanced Electromagnetic Technology International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma PhysicsSchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China Institute of Plasma Physics Chinese Academy of SciencesHefei 230031People’s Republic of China

Density limit has long been a widely studied issue influencing the operating range of *** rapid growth of the m/n=2/1(where m and n are poloidal and toroidal mode numbers,respectively)tearing mode is generally regarded as a primary precursor to the density limit *** this experiment,the coupling of the m/n=1/1 mode and the m/n=2/1 mode in highdensity plasma was *** a sawtooth cycle,the frequencies of the two modes gradually converge until they become *** that,toroidal coupling occurs between the 1/1 and 2/1 modes,resulting in a mutually fixed phase *** the occurrence of toroidal coupling,the 2/1 mode is *** to the disruption,the cessation of the 1/1 and 2/1 mode coupling,along with the rapid growth in the amplitude of the 2/1 mode,can be ***,under the same parameters,comparing discharges with or without the 1/1 mode,it is found that the presence of the 1/1 mode leads to higher plasma density and temperature parameters.

关键词： toroidal coupling tearing mode density limit sawtooth

Development of a compact torus injection system for the Keda Torus eXperiment

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Plasma Science and Technology 2022年第4期24卷 114-123页

作者： Chen CHEN Tao LAN Chijin XIAO Ge ZHUANG Defeng KONG Shoubiao ZHANG Sen ZHANG weixing DING Zhengwei WU Wenzhe MAO Jie WU Hangqi XU Jiaren WU Yiming ZU Dong ZHANG zian wei Xiaohui WEN Chu ZHOU Ahdi LIU Jinlin XIE Hong LI Wandong LIU Department of Plasma Physics and Fusion Engineering University of Science and Technology of ChinaHefei 230026People's Republic of China Department of Physics and Engineering Physics University of SaskatchewanSaskatoon SK S7N 5E2Canada Institute of Plasma Physics Chinese Academy of SciencesHefei 230031People's Republic of China

A compact torus injection system,KTX-CTI,has been developed for the planned injection experiments on the Keda Torus e Xperiment(KTX)reversed field pinch(RFP)device to investigate the physics and engineering issues associated with interaction between a compact torus(CT)and *** key interests include fueling directly into the reactor center,confinement improvement,and the injection of momentum and helicity into the RFP *** CT velocity and mass have been measured using a multichannel optical fiber interferometer,and for the first time the time evolution of the CT density profile during CT propagation is *** effects of discharge parameters on the number of injected particles,CT velocity and CT density have been characterized:the maximum hydrogen CT plasma mass,m,CTis 50μg,corresponding to 30%of the mass in a typical KTX plasma;the CT velocity exceeds 120 km *** is observed for the first time that multiple CTs can be produced and emitted during a very short period(<100μs)in one discharge,which is significant for the future study of repetitive CT injection,even with an ultra-high frequency.

关键词： compact torus injection central fueling reversed field pinch

Preliminary compact torus injection experiments on the Keda Torus eXperiment reversed field pinch

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Plasma Science and Technology 2024年第10期26卷 56-64页

作者： Tao LAN Chen CHEN Chijin XIAO weixing DING Jie WU Wenzhe MAO Sen ZHANG Defeng KONG Shoubiao ZHANG Zhengwei WU Qilong DONG Yongkang ZHOU Hangqi XU Jiaren WU zian wei Xiaohui WEN Hai WANG Chu ZHOU Adi LIU Hong LI Jinlin XIE Wandong LIU Ge ZHUANG Department of Plasma Physics and Fusion Engineering University of Science and Technology of ChinaHefei 230026People’s Republic of China Plasma Physics Laboratory University of SaskatchewanSaskatoon SK S7N 5E2Canada Institute of Plasma Physics Chinese Academy of SciencesHefei 230031People’s Republic of China

A new compact torus injector(KTX-CTI)has been built for injection experiments on the Keda Torus eXperiment(KTX)reversed field pinch(RFP).The aim is to study the fundamental physics governing the compact torus(CT)central fueling *** experiments conducted under the sole influence of a 0.1 T toroidal magnetic field,the injected CT successfully penetrated the entire toroidal magnetic field,reaching the inner wall of the KTX vacuum *** reaching the inner wall,the CT diffused both radially outward and toroidally within the vessel at a discernible diffusion ***,the inherent helicity within the CT induced a modest KTX plasma current of 200 A,consistent with predictions based on helicity *** injection demonstrated the capability to initiate KTX discharges at low loop voltages,suggesting its potential as a pre-ionization and current startup *** RFP discharges featuring CT injection,the central plasma density was found to exceed the Greenwald density limit,with more peaked density profiles,indicating the predominant confinement of CT plasma within the core region of the KTX bulk plasma.

关键词： compact torus fueling reversed field pinch density limit

Fast radial scanning probe system on KTX

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Plasma Science and Technology 2020年第4期22卷 97-104页

作者： Tijian DENG Tao LAN Mingsheng TAN Junfeng ZHU Jie WU Hangqi XU Chen CHEN Yolbarsop ADIL Sen ZHANG Jiaren WU Yiming ZU Wenzhe MAO Hong LI Jinlin Xie Ahdi LIU Zixi LIU Zhengwei WU Hai WANG Xiaohui WEN Haiyang ZHOU zian wei Chijin XIAO weixing DING Ge ZHUANG Wandong LIU KTX Laboratory and Department of Engineering and Applied Physics University of Science and Technology of ChinaHefei 230026People's Republic of China Plasma Physics Laboratory University of SaskatchewanSaskatoonSK S7N 5E2Canada

A fast radial scanning probe system was constructed for the Keda Torus eXperiment(KTX)to measure the profiles of boundary plasma parameters such as floating potential,electron density,temperature,transport fluxes,*** scanning probe system is driven by slow and fast motion mechanisms,corresponding to the stand-by movement of a stepping motor and the fast scanning movement of a high-torque servo-motor,*** fast scanning,the scanner drives the probe radially up to 20 cm at a maximum velocity of 4.0 m s-1.A noncontact magnetic grating ruler with a high spatial resolution of 5μm is used for the displacement *** scanning probe can reach the center of plasmas *** comparison of plasma floating potential profiles obtained by a fixed radial rake probe and the single scanning probe suggests that the high-speed scanning probe system is reliable for measuring edge plasma parameter profiles on the KTX device.

关键词： radial scanning probe high-speed movement noncontact magnetic grating ruler

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恩替卡韦治疗慢性乙型肝炎近期临床研究

中国药房 2007年第11期18卷 856-857页

作者：李纯平魏子安张海涛何淑英唐山市传染病院唐山市063000 唐山市协和医院唐山市063000

目的:研究恩替卡韦治疗慢性乙型肝炎的近期疗效和安全性。方法:80例患者随机均分为治疗组(给予恩替卡韦治疗)与对照组(给予阿德福韦酯治疗),2组HBeAg阳性和HBeAg阴性患者均各20例,观察治疗12wk时的应答效果。结果:治疗12wk时,治疗组与... 详细信息

目的:研究恩替卡韦治疗慢性乙型肝炎的近期疗效和安全性。方法:80例患者随机均分为治疗组(给予恩替卡韦治疗)与对照组(给予阿德福韦酯治疗),2组HBeAg阳性和HBeAg阴性患者均各20例,观察治疗12wk时的应答效果。结果:治疗12wk时,治疗组与对照组HBeAg阳性患者HBV DNA转阴率分别为90%、40%(P0.05),HBeAg阴性患者ALT复常率分别为85%、65%(P>0.05)。2组均未发现明显不良反应。结论:恩替卡韦治疗慢性乙型肝炎12wk时,HBV DNA转阴率明显优于阿德福韦酯,而ALT复常率无明显差异。

关键词：恩替卡韦阿德福韦酯慢性乙型肝炎近期疗效

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盐雾环境下瓷及复合绝缘子积污特性模拟研究

电力科学与工程 2021年第10期37卷 71-78页

作者：吕玉坤魏壮魏子安汪岳池王欣华北电力大学能源动力与机械工程学院河北保定071003

盐雾环境下的污秽物具有较高的可溶盐含量,可造成绝缘子绝缘性能下降,进而危及电力系统的安全运行。以XWP2-160型瓷双伞绝缘子和FXBW-110/120-2型复合绝缘子为研究对象,基于场致荷电机理,利用多物理场耦合软件COMSOL对其积污特性进行数... 详细信息

盐雾环境下的污秽物具有较高的可溶盐含量,可造成绝缘子绝缘性能下降,进而危及电力系统的安全运行。以XWP2-160型瓷双伞绝缘子和FXBW-110/120-2型复合绝缘子为研究对象,基于场致荷电机理,利用多物理场耦合软件COMSOL对其积污特性进行数值模拟,探索了盐密ESDD的计算方法,并验证了其合理性。利用该方法研究了盐雾环境下风速、雾滴粒径、电压类型对瓷及复合绝缘子积污特性的影响,分析了污秽沿绝缘子伞裙的分布规律。结果表明:复合绝缘子的积污量大于同条件下瓷双伞绝缘子积污量,盐雾环境频发地区可优先考虑瓷双伞绝缘子;直流电压下,瓷及复合绝缘子的积污量增长趋势均与风速、粒径呈正相关;复合绝缘子积污量沿伞裙近似呈U型分布,瓷双伞绝缘子积污量沿伞裙近似呈M型分布,且风速越大分布趋势越明显。

关键词：瓷双伞绝缘子复合绝缘子数值模拟积污特性等值盐密盐雾环境

Polarimeter–interferometer diagnostic using terahertz solid-state sources for fluctuation measurements on Keda Torus e Xperiment(KTX)

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Plasma Science and Technology 2024年第3期26卷 61-65页

作者：汪兴康毛文哲谢锦林兰涛李弘刘阿娣周楚温晓辉卫子安吴捷陈晨刘东宽饶贤昊蔡虎邬佳仁邓鹏刘海庆丁卫星庄革刘万东 School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026People's Republic of China Institute of Plasma Physics Chinese Academy of SciencesHefei 230031People's Republic of China

A multi-channel polarimeter-interferometer has been developed on the Keda Torus eXperiment(KTX)for the study of equilibrium dynamics and internal magnetic fluctuations.A three-wave technique based on terahertz solid-state sources(-650 GHz)is applied for simultaneous measurements of electron density and Faraday rotation *** output power of the microwave source is 2 *** rotation effect using a rotating wave plate is tested with phase noise less than 0.8°,and the density phase noise is less than 0.9°.Measurement of Faraday rotation angle and density for discharges on KTX have demonstrated high sensitivity to internal MHD activities.

关键词： plasma diagnostics interferometry terahertz polarimeter