• Title, Summary, Keyword: Plasma discharge

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Analysis of characteristics of discharge in liquid

  • Kim, Ju-Sung;Min, Boo-Ki;Hong, Young-June;Kang, Seong-Oun;Choi, Eun-Ha
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.209.2-209.2
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    • 2016
  • Up to now, Plasma applications are thought as a leading technology in industrial, chemical and even medical and biological field. Especially, Due to direct discharge in liquid with reaction in ambient solution, plasma in liquid is useful plasma technology. Such as electro-surgery, water purification, radical generation for synthesis. For using those plasma applications efficiently, plasma characteristics should be understood in advance. But discharge in liquid is not much well-known about its characteristics. And plasma discharge in solution is difficult to generate and analysis due to electrolysis, vaporization and radical generation. So, We make stable plasma discharge in solution(saline 0.9%) without input gas. We also analyze new type of plasma source in thermal and electrochemical view. And we check characteristics of plasma in liquid. For example, plasma density and radical density(OH) with optical emission, thermal energy with thermometer, electrical energy with oscilloscope and so on. And we try to explain the bubble and plasma formation with circuit analysis.

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Prediction of electric dynamics of electric discharge machining using Plasma model (플라즈마 모델을 이용한 방전가공의 전기적 거동 예측)

  • Kim K.W.;Jeong Y.H.;Min B.K.;Lee S.J.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.604-607
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    • 2005
  • In the electro-discharge machining the machining performance is closely related to the characteristics of discharge which can be identified from electrical behavior in gap between workpiece and electrode. Therefore, the accurate prediction of electrical behavior in electro-discharge machining (EDM) is useful to process control and optimization. However, any simulation model fur prediction of electrical behavior in EDM process has never been reported until now. In this study, a simulation model is developed to analyze the electrical behavior of electro-discharge plasma which significantly influences electrical behavior in EDM process. For the purpose of this the fundamentals of electro-discharge mechanism such as inception, propagation, formation of plasma channel and termination are investigated to accurately predict the cycle of discharge plasma in EDM. As a result, a mathematical model of electro-discharge plasma is constructed with considering the fundamentals of electro-discharge plasma. Consequently, it is demonstrated that the developed model can predict the electrical behavior of plasma such as electron density in various conditions.

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Multi-hole RF CCP 방전에서 방전 주파수가 미치는 영향

  • Lee, Heon-Su;Lee, Yun-Seong;Seo, Sang-Hun;Jang, Hong-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.145-145
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    • 2011
  • Recently, multi-hole electrode RF capacitively coupled plasma discharge is being used in the deposition of microcrystalline silicon for thin film solar cell to increase the speed of deposition. To make efficient multi-hole electrode RF capacitively coupled plasma discharge, the hole diameter is to be designed concerning the plasma parameters. In past studies, the relationship between plasma parameters such as pressures and gas species, and hole diameter for efficient plasma density enhancement is experimentally shown. In the presentation, the relationship between plasma deriving frequency and hole diameter for efficient multi-hole electrode RF capacitively coupled plasma discharge is shown. In usual capacitively coupled plasma discharge, plasma parameter, such as plasma density, plasma impedence and plasma temperature, change as frequency increases. Because of the change, the optimum hole diameter of the multi-hole electrode RF capacitively coupled plasma for high density plasma is thought to be modified when the plasma deriving frequency changes. To see the frequency effect on the multi-hole RF capacitively coupled plasma is discharged and one of its electrode is changed from a plane electrode to a variety of multi-hole electrodes with different hole diameters. The discharge is derived by RF power source with various frequency and the plasma parameter is measured with RF compensated single Langmuir probe. The shrinkage of the hole diameter for efficient discharge is observed as the plasma deriving frequency increases.

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A Study of Flexible BLU Using Plasma Discharge Ouster (플라즈마 방전 클러스터를 이용한 플렉시블 백라이트 유닛 연구)

  • Ryu, Si-Hong;Koo, Kyo-Uk;Lee, Seong-Eui
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.324-325
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    • 2008
  • In this Study, We fabricated a plasma discharge cluster with external electrodes which can be applied to flexible backlight in a polymer substrate and investigated the discharge characteristics. The Sealing process was progressed in vacuum chamber, which enable to fabricate plasma discharge cluster. The results of discharge characteristics show that the static memory margin of plasma discharge cluster was increased, as Ne/Xe(5%) gas pressure was increased. also, When gas pressure was 100torr at 600um of electrode gap, we have obtained high luminance of a plasma discharge cluster.

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A Compact Pulse Corona Plasma System with Photocatalyst for an Air Conditioner (광촉매와 조합된 코로나 방전 플라즈마 필터의 유해 가스 및 입자 제거 특성)

  • Shin, Soo-Youn;Moon, Jae-Duk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.1
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    • pp.151-155
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    • 2007
  • A compact discharge plasma system with a photocatalyst has been proposed and investigated experimentally for application to air conditioners. It was found that there was intense ultra violet radiation with high energy of 3.2 eV from the corona discharge due to the DC-biased pulse voltage applied on a wire. An electrophotochemical reaction took place apparently on the surfaces of the photocatalyst of $TiO_2$ irradiated ultra violet front the discharge plasma in the proposed plasma system. The proposed discharge plasma system with the photocatalyst of $TiO_2$ showed very high removal efficiency of VOCs by tile additional electrophotochemical reactions on the photocatalyst. The proposed discharge plasma system also showed very high removal efficiency of particles such as smokes, suspended bacteria, and pollen and mite allergens by the electrostatic precipitation part. This type of corona discharge plasma system with a photocatalyst can be used as an effective means of removing both indoor pollutant gases and particles including suspended allergens.

Analysis of reactive species in water activated by plasma and application to seed germination

  • Choi, Ki-Hong;Lee, Han-Ju;Park, Gyungsoon;Choi, Eun-Ha
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.162.1-162.1
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    • 2015
  • The use of plasma has increased in bio-application field in recent years. Particularly, water treated by arc discharge or atmospheric pressure plasma has been actively utilized in bio-industry. In this study, we have developed a plasma activated water generating system. For this system, two kinds of plasma sources; dielectric barrier discharge (DBD) plasma and arc discharge plasma have been used. The discharge energy was calculated using the breakdown voltage and current, and the emission spectrum was measured to investigate the generated reactive species. We also analyzed the amount of reactive oxygen and nitrogen species in water using the chemical methods and nitric oxide sensor. Finally, the influence of plasma generated reactive species on the germination and growth of spinach (Spinacia oleracea) was investigated. Spinach is a green leafy vegetable that contains a large amount of various physiologically active organic compounds. However, it is characterized with a low seed germination rate.

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Study on Characteristics of DBD Plasma Actuator as Design Parameters for Plasma Flow Control (플라즈마 유동제어를 위한 DBD 플라즈마 액츄에이터의 설계변수에 따른 특성 연구)

  • Yun, Su-Hwan;Kwon, Hyeok-Bin;Kim, Tae-Gyu
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.6
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    • pp.492-498
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    • 2012
  • Characteristics of DBD(Dielectric Barrier Discharge) plasma actuator as design parameters were investigated for plasma flow control. Flow velocity and power consumption of the DBD plasma actuator were measured according to the design parameters such as discharge voltage and frequency, gap, width and length of electrode, and the thickness of dielectric barrier. The flow velocity and power consumption increased as the discharge voltage and frequency increased. As the electrode gap increased, the flow velocity increased with decreasing the power consumption, whereas high voltage was required for the plasma discharge. The flow velocity increased as the upper-electrode width decreased, and as the lower-electrode width increased at the constant power consumption. The performance of the DBD plasma actuator can be estimated at the given discharge and geometry conditions.

A Trial for Improvement of Energy Efficiency of Plasma Reactor by Superposing Two Heterogeneous Discharges - Characteristics of Surface and Corona Discharge Combined Plasma Reactor - (이종방전 중첩에 의한 방전 플라스마반응기의 효율개선의 시도 - 연면.직류코로나 방전 중첩형 반응기의 특성 -)

  • ;Mizuki Yamaguma
    • Journal of the Korean Society of Safety
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    • v.15 no.3
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    • pp.66-70
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    • 2000
  • In order to cope with environmental problems caused by harmful gases emitted from various industrial sources, a new technology which employs discharge plasma formed in ordinary atmospheric pressure has been intensively investigated in many industrialized nations. Although a plenty of useful outcomes and suggestions have been made public by scientists in this field, few commercial products which effectively decompose pollutant gases have appeared as yet. This is partly because that the energy efficiency of a most effective plasma reactor has not reached a satisfactory level in comparison with those of devices using conventional technologies. In an attempt to solve the problem mentioned above, we noticed to combine heterogeneous electrical discharges. This concepts is based on that each plasma reactor has its specific spatial region in which chemical reaction are active and by electrically affected with another reactor of different type, the activated region would increase - which may lead to cutting down the energy consumption. To prove this concept experimentally, two different discharge equipments, a plane ceramic-based surface discharge electrode and a corona electrode with tungsten needle may, are selected and combined to fabricate a hybrid plasma reactor. The results are summarized as follows; (1) Ozone concentration generated in the plasma region drastically increases when the positive corona discharge is added to the surface discharge. The rate of increase of ozone depends on the frequency of the surface discharge. The negative corona, however, does not contribute to the improvement of the ozone generation. (2) NO(nitrogen monoxide) decomposition rate also improves by simultaneously applying the surface and the positive corona discharges. The effect of the corona superposition is more evident when the level of the surface discharge is moderate. (3) By adjusting the corona level, the net energy efficiency during NO decomposition improves in comparison with the simple surface discharge reactor.

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Effect of Self-Erase Discharge on the Luminous Efficacy of Long Gap AC PDPs

  • Kim, Tae-Jun;Jung, Jae-Chul;Jung, Hae-Yoon;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.585-588
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    • 2007
  • We studied the effect of self-erase discharge on the luminous efficacy of ac PDPs. We observed through discharge current analysis to confirm that the selferase discharge occurred mainly between sustain cathode and address electrode, which have an influence on the luminous efficacy. The amount and timing of the self-erase discharge was varied to observe its effect on the luminous efficacy. It has been found that the luminous efficacy could be improved by the self-erase discharge when it is adjusted to occur right before the main discharge in the small gap structure. In the long gap structure, on the contrary, the luminous efficacy could be increased when the self-erase discharge is suppressed. Also, various waveforms to control self-erase discharge are suggested and tested in the panel experiments.

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Effects of the Capacitive Field in an Inductively Coupled Plasma Discharge

  • Choe, HeeHwan
    • Applied Science and Convergence Technology
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    • v.26 no.5
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    • pp.114-117
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    • 2017
  • Plasma characteristics of two-dimensional inductively coupled discharge simulation is investigated. Impedance of an inductively coupled plasma discharge was considered. Voltage drops across antenna coils and current variation between coils made different profiles of plasma characteristics. Importance of the capacitive field effect in some case was analyzed.