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discharge characteristics of different lightning air terminals under composite voltages

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Plasma Science and Technology 2019年第5期21卷 1-4页

作者： Chijie ZHUANG Zezhong WANG Rong ZENG Lei LIU Te LI Min LI Yingzhe CUI Jinliang HE Department of Electrical Engineering Tsinghua University State Grid Jibei Electric Economic Research Institute China Southern Grid (CSG) Electric Power Research Institute Electric Power Research Institute of Zhejiang Power Grid

Different types of lightning air terminals have been designed over the *** regarding the effect of different types of air terminals,especially the early streamer emission(ESE)-type,remains *** paper describes the discharge characteristics of different types of air terminals,two of which are quite similar to the ESE-type dynasphere,and concludes that the tested non-standard air terminals have discharge characteristics similar to those of Franklin rods and that their lightning protection performance should be similar.

关键词： air terminal lightning protection discharge characteristics composite voltage leader

Investigation of optimum discharge characteristics and chemical activity of AC driven air plasma jet and its anticancer effect

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Plasma Science and Technology 2021年第12期23卷 63-73页

作者： Sansan PENG Dehui XU Miao QI Rong LIU Xinying ZHANG Huaiyan ZHANG Bolun PANG Jin ZHANG Hao ZHANG Zhijie LIU Dingxin LIU State Key Laboratory of Electrical Insulation and Power Equipment Centre for Plasma BiomedicineXi'an Jiaotong UniversityXi'an 710049People's Republic of China The School of Life Science and Technology Xi'an Jiaotong UniversityXi'an 710049People's Republic of China

In this study,we investigated the effects of the quartz tube diameter,air flow rate,and applied voltage on the characteristics of an air plasma jet to obtain the optimized discharge *** physicochemical properties and concentration of reactive oxygen and nitrogen species(RONS)in plasma-activated medium(PAM)were characterized to explore their chemical ***,we investigated the inactivation effect of air plasma jet on tumour cells and their corresponding inactivation *** results show that the tube diameter plays an important role in sustaining the voltage of the air plasma jet,and the gas flow rate affects the jet length and discharge ***,the air plasma jet discharge displays two modes,namely,ozone and nitrogen oxide modes at high and low gas flow rates,*** the voltage increases the concentration of reactive species and the length of *** evaluating the viability of A549 cells under different parameters,the optimal treatment conditions were determined to be a quartz tube diameter of 4 mm,gas flow rate of 0.5 SLM,and voltage of 18 k ***,an air plasma jet under the optimized conditions effectively enhanced the chemical activity in PAM and produced more aqueous *** air plasma jet induced significant cytotoxicity in A549 cancer cells after plasma treatment.H_(2)O_(2) and NO_(2) are regarded as key factors in promoting cell *** present study demonstrates the potential use of tumour cell therapy by atmospheric air PAM,which aids a better understanding of plasma liquid chemistry.

关键词： cold atmospheric plasma discharge characteristics reactive species plasma-activated medium anticancer effect

Improvement in discharge characteristics and energy yield of ozone generation via configuration optimization of a coaxial dielectric barrier discharge reactor

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Chinese Journal of Chemical Engineering 2023年第8期60卷 61-68页

作者： Chuang Liang Zhihao Liu Baochang Sun Haikui Zou Guangwen Chu State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China Research Center of the Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical TechnologyBeijing 100029China

Dielectric barrier discharge (DBD) has been widely employed in ozone ***,the technology still exhibits relatively low energy yield (E_(Y)) referring to its theoretical *** this work,E_(Y)of ozone generation was improved by optimizing the mesh number,electrode length,and dielectric material in a coaxial DBD reactor with two wire mesh ***,the discharge characteristics were investigated to elucidate the effect of reactor configuration on E_(Y).Results showed that the discharge characteristics were improved by increasing the mesh number,electrode length,and relative *** the mesh number was increased from 40 to 100,an improvement of approximately 48%in E_(Y) was ***,higher E_(Y) values were obtained using corundum as the dielectric material relative to polytetrafluoroethylene and ***,E_(Y) in the optimal DBD reactor could reach 326.77 g·(k W·h)^(-1).Compared with the reported DBD reactor,the coaxial DBD reactor with the mesh electrode and the dielectric material of corundum could effectively improve E_(Y),which lays a foundation for the design of high-efficiency coaxial DBD reactor.

关键词： Coaxial DBD reactor Configuration optimization Ozone generation discharge characteristics Energy yield

Experimental and numerical simulation study of the effect for the anode positions on the discharge characteristics of 300W class low power Hall thrusters

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Plasma Science and Technology 2023年第1期25卷 100-110页

作者：陈新伟高俊杨三祥耿海郭宁顾左杨俊泰张宏 Science and Technology on Vacuum Technology and Physics Laboratory Lanzhou Institute of PhysicsLanzhou 730000People's Republic of China

Low-power Hall thruster(LHT) generally has poor discharge efficiency characteristics due to the large surface-to-volume *** to further refine and improve the performance of 300 W class LHT in terms of thrust and efficiency,and to obtain the most optimal operating point,the experimental study of the discharge characteristics for three different anode positions was conducted under the operation of various discharge voltages(100-400 V) and anode mass flow rates(0.65 mg·s-1and 0.95 mg·s-1).The experimental results indicated that the thruster has the most excellent performance in terms of thrust and efficiency etc at a channel length of 27 mm for identical operating *** addition,particle in cell simulations,employed to reveal the underlying physical mechanisms,show that the ionization and acceleration zone is pushed downwards towards the channel exit as the anode moves towards the *** the identical operating point,when the channel length is reduced from 32 to 27 mm,the ionization and acceleration zone moves towards the exit,and the parameters such as thrust and efficiency increase due to the high ionization rate,ion number density,and axial electric *** the channel length is further moved to 24 mm,the parameters in terms of thrust(F) and efficiency(ηa) are reduced as a result of the decreasing ionization efficiency(ηm) and the larger plume divergence angle(α).In this paper,the results indicated that an optimum anode position(ΔL=27 mm) exists for the optimum performance.

关键词： low-power Hall thruster discharge characteristics PIC-MCC simulation anode positions

Simulation Studies of Rib Structure Effect on discharge characteristics of Plasma Display Panel

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Plasma Science and Technology 2007年第1期9卷 80-88页

作者：丁可邓斌单莉英孙琦顾昌鑫 Department of Materials Science Fudan UniversityShanghai 200433China

To investigate the effect of the rib structure on the discharge characteristics of the plasma display panel, the potential distribution, particles density distribution and ions incident angle distribution were examined by simulation of a two-dimensional particle-in-cell/Monte Carlo collision, with two kinds of rib structure： the stripe rib structure and the Waffle rib structure. The results showed that the distribution of electric potential at the corner of the discharge cell was almost the same for these two rib structures while in the centre there was a difference between these two rib structures. The striation phenomenon could be observed in both cases. The distribution of density also indicated that the striation phenomenon was accompanied by the firing of discharge, and the Waffle rib structure might reduce the density humps. In the cell with a stripe rib structure, the profiles of the surface charge density along the sustained dielectric layer presented a better fluctuating distribution than that in the cell with a Waffle rib structure. The spatial potential and particle density in the discharge bulk showed that the Waffle ribs could weaken the striation phenomenon, which could be explained by the decrease in the particle numbers in the discharge cell. The simulation results of the ion incident angle showed that most ions impacted the sustained dielectric layer in the normal stripe rib cell with an incident angle in the range of 6° to 19° while with the Waffle rib structure the incident angle of most ions was in the range of 4° to 19°. The Waffle rib structure did not affect the angle distribution of incident ions significantly.

关键词： discharge characteristics surface charge ion angle distribution plasma display panel

Particle-in-cell simulation for effect of anode temperature on discharge characteristics of a Hall effect thruster

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Plasma Science and Technology 2018年第12期20卷 96-106页

作者： Hong LI Xingyu LIU Zhiyong GAO Yongjie DING Liqiu WEI Daren YU Xiaogang WANG Plasma Propulsion Laboratory Harbin Institute of TechnologyHarbin 150001People's Republic of China AECC Harbin Dongan Engine(Group)Corporation Ltd Harbin 150066People's Republic of China Department of Physics Harbin Institute of TechnologyHarbin 150001People's Republic of China

Propellant gas flow has an important impact on the ionization and acceleration process of Hall effect thrusters （HETs）. In this paper, a particle-in-cell numerical method is used to study the effect of the anode temperature, i.e., the flow speed of the propellant gas, on the discharge characteristics of a HET. The simulation results show that, no matter the magnitude of the discharge voltage, the calculated variation trends of performance parameters with the anode temperature are in good agreement with the experimental ones presented in the literature. Further mechanism analysis indicates that the magnitude of the electron temperature is responsible for the two opposing variation laws found under different discharge voltages. When the discharge voltage is low, the electron temperature is low, and so is the intensity of the propellant ionization; the variation of the thruster performance with the anode temperature is thereby determined by the variation of the neutral density that affects the propellant utilization efficiency. When the discharge voltage is high, the electron temperature is large enough to guarantee a high degree of the propellant utilization no matter the magnitude of the anode temperature. The change of the thruster performance with the anode temperature is thus dominated by the change of the electron temperature and consequently the electron-neutral collisions as well as the electron cross-field mobility that affect the current utilization efficiency.

关键词： Hall effect thruster anode temperature neutral flow discharge characteristics particle-in-cell simulation

Investigation on plasma structure evolution and discharge characteristics of a single-stage planar-pulsed-inductive accelerator under ambient fill condition

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Chinese Physics B 2020年第11期29卷 398-405页

作者： Xiao-Kang Li Bi-Xuan Che Mou-Sen Cheng Da-Wei Guo Mo-Ge Wang Yun-Tian Yang College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China

The physical process of a single-stage planar-pulsed-inductive accelerator is *** include the waveforms of circuit current,capacitor voltage,plasma radiation intensity,and temporal plasma structure photos captured by a high-speed *** are conducted under static ambient fill condition using argon as *** values of capacitor voltage and gas pressure are *** discussions quantify the EM interaction between circuit and plasma,as well as their energy deposition and current sheet *** on the results of experiments,physical mechanisms of the initial ionization phase and the following acceleration phase are analyzed theoretically.

关键词： electric propulsion pulsed-inductive thruster discharge characteristics plasma structure

Investigation on discharge characteristics of a coaxial dielectric barrier discharge reactor driven by AC and ns power sources

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Plasma Science and Technology 2018年第3期20卷 78-86页

作者： Qian WANG Feng LIU Chuanrun MIAO Bing YAN Zhi FANG College of Electrical Engineering and Control Science Nanjing Tech University Nanjing 211816 People＇ s Republic of China

A coaxial dielectric barrier discharge（DBD） reactor with double layer dielectric barriers has been developed for exhaust gas treatment and excited either by AC power or nanosecond（ns）pulse to generate atmospheric pressure plasma. The comparative study on the discharge characteristics of the discharge uniformity, power deposition, energy efficiency, and operation temperature between AC and ns pulsed coaxial DBD is carried out in terms of optical and electrical characteristics and operation temperature for optimizing the coaxial DBD reactor performance. The voltages across the air gap and dielectric layer and the conduction and displacement currents are extracted from the applied voltages and measured currents of AC and ns pulsed coaxial DBDs for the calculation of the power depositions and energy efficiencies through an equivalent electrical model. The discharge uniformity and operating temperature of the coaxial DBD reactor are monitored and analyzed by optical images and infrared camera. A heat conduction model is used to calculate the temperature of the internal quartz tube. It is found that the ns pulsed coaxial DBD has a much higher instantaneous power deposition in plasma, a lower total power consumption, and a higher energy efficiency compared with that excited by AC power and is more homogeneous and stable. The temperature of the outside wall of the AC and ns pulse excited coaxial DBD reaches 158 ℃ and 64.3 ℃ after 900 s operation, *** experimental results on the comparison of the discharge characteristics of coaxial DBDs excited by different powers are significant for understanding of the mechanism of DBDs,reducing energy loss, and optimizing the performance of coaxial DBD in industrial applications.

关键词： coaxial dielectric barrier discharge discharge characteristics nanosecond pulse,operation temperature

A global model for evaluating discharge characteristics and performance of hollow cathodes

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Chinese Journal of Aeronautics 2024年第9期37卷 72-84页

作者： Feng TIAN Long MIAO Qimeng XIA Zhiwen WU Ningfei WANG Xiao HOU School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Chongqing Innovation Center Beijing Institute of TechnologyChongqing 404100China

Hollow cathode,with the highest plasma density,current density,and temperature,becomes one of the most important components in the electro-thruster *** the electric-propulsion thruster performance is directly related to the ionization rate,reliability,and lifetime of the hollow cathode,this paper develops a global model to study the effects of discharge current,gas flow rate,and gas species on the discharge characteristics in the insert and orifice regions of the hollow *** emitter wall temperatures of hollow cathodes predicted by the global model are compared with experimental results from NSTAR thruster neutralization cathodes,confirming the model's *** influence of hollow cathode emitter material and structure sizes on the plasma parameters in the internal regions was also *** simulation results show that there is an optimal matching relationship between the discharge current and gas flow rate to guarantee the maximum ionization *** optimal working region for the hollow cathode has been deter-mined under different energetic,regime and structural *** global model established in this paper can quickly determine the key structure and operating parameters of hollow cathode at the design stage,and provide the theoretical basis for hollow cathode design and development.

关键词： Hollow cathode Global model Electric propulsion discharge characteristics Optimal matching relationship