• Title/Summary/Keyword: Electron behavior

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A Fundamental Study on the Electron Behavior and Optimum Condition for the Formation of a Neutral Loop Discharge Plasma (Neutral Loop Discharge 플라즈마의 전자거동과 최적조건에 관한 기초적 연구)

  • Sung, Youl-Moon;Kim, Jong-Kyung;Park, Chung-Hoo
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.6
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    • pp.281-287
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    • 2001
  • In order to obtain guidelines for design and operation of a new plasma source by a magnetic neutral loop discharge(NLD), the electron behavior was studied experimentally and numerically. Experimentally, the magnetic field gradient was changed over a wide range, and it was found that there existed an optimum value for efficient plasma production. Analyses of the electron behavior were performed using a model that included effects of a three dimensional electromagnetic field configuration considering the spatial decay of the electric field, and the limitation to the motion of electron caused by the existence of walls and thus electron loss at wall surfaces. These three dimensional factors were found to explain the existence of the optimum magnetic field gradient. It was shown that the L dependence of the plasma production efficiency was firstly decided by the finite decay length of the electric field strength, which was further modified by electron elastic collisions with neutral atoms which drove the electron to walls. The latter effect tends to reduce the optimum value of L.

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Laser Thomson Scattering Measurements and Modelling on the Electron Behavior in a Magnetic Neutral Loop Discharge Plasma

  • Sung, Youl-Moon;Kim, Hee-Je;Park, Chung-Hoo
    • KIEE International Transactions on Electrophysics and Applications
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    • v.11C no.4
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    • pp.107-112
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    • 2001
  • Laser Thomson scattering measurements of electrom temperature and density in a neutral loop discharge (NLD) plasma were performed in order to reveal the electron behavior around the neutral loop (NL). The experimental results were examined by using a simulation model that included effects of a three dimensional electromagnetic field with spatial decay of the RF electric field, and the limitation of the spatial extent of the electron motion and collision effect. From the experiments and modeling of the electron behavior, it was found that NLD plasma posses the electron temeprature $T_{e}$ and density ne peaks around the NL is essential for the formation of plasma. Also, the optimum condition of plasma production could be simply estimated by the calculation of $U_{av}$ and $F_{0}$././.

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Investigation on Optimum Plasma Production Condition of a Magnetic Neutral Loop Discharge System (자기중성선방전 시스템의 최적 플라즈마 생성조건에 관한 고찰)

  • Sung, Youl-Moon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.11
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    • pp.2236-2241
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    • 2009
  • In this study, the electron behavior was investigated numerically in order to obtain guidelines for design and operation of a new plasma source by a magnetic neutral loop discharge (NLD). The optimum plasma production was investigated by using a 3-dimensional simulation model which enables the electron behavior calculation from source region to downstream region. The results showed that the high-density plasma produced around the magnetic neutral loop (NL) is transferred from the NL region to the downstream region along magnetic force lines. Also the avaraged electron energy is increased with the normalized RF electric field (F), which can be used to characterize the plasma production efficiency of NLD system. Considering the relation between F and plasma production, in-depth plasma control can be achieved at a given specific process condition.

A simple analysis on the abnormal behavior of the argon metastable density in an inductively coupled Ar plasma

  • Park, Min;Yu, Sin-Jae;Kim, Jeong-Hyeong;Seong, Dae-Jin;Sin, Yong-Hyeon;Jang, Hong-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.438-438
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    • 2010
  • The abnormal behavior of the argon metastable density during the E-H mode transition in argon ICP discharge was investigated. Lots of investigations including global models expected that during and after the mode transition of ICP discharge, the density of metastable increases with applied rf power (i.e. electron density). However, recent direct measurement of metastable density revealed that the metastable density of argon decreases with the applied power during and after the mode transition. This result may not be explained by the previous global model which is based on the assumption of the Maxwellian electron energy distribution function (EEDF). In this paper, to explain this abnormal behavior with simple manners, a simple global model taking account of the effect of the non-Maxwellian EEDFs incorporating into a set of coupled rate equations is proposed. The result showed that the calculated metastable density taking account of non-Maxwellian EEDF and its evolution during the transition has an abnormal behavior with electron density and is in good agreement with the previous measurement results, indicating the close coupling of electron kinetics and the behavior of metastable density. The proposed simple model is expected to provide qualitative kinetic insight to understand the behavior of the metastable density in various plasma discharges which typically exhibit non-Maxwellian distribution.

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Chemical and Thermal Characterizations of Electron Beam Irradiated Jute Fibers (전자빔 조사된 황마섬유의 화학적 및 열적 특성분석)

  • Ji, Sang Gyu;Cho, Donghwan;Lee, Byung Cheol
    • Journal of Adhesion and Interface
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    • v.11 no.4
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    • pp.162-167
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    • 2010
  • In the present work, the effect of electron beam irradiation on the chemical and thermal characteristics of cellulose-based jute fibers was explored by means of chemical analysis, electron spin resonance analysis, ATR-FTIR spectroscopy, thermogravimetric analysis and thermomechanical analysis. Jute fiber bundles were uniformly irradiated in the range of 2~100 kGy by a continuous method using a conveyor cartin an electron beam tunnel. Electron beam treatment, which is a physical approach to change the surfaces, more or less changed the chemical composition of jute fibers. It was also found that the radicals on the jute fibers can be increasingly formed with increasing electron beam intensity. However, the electron beam irradiation did not change significantly the chemical functional groups existing on the jute fiber surfaces. The electron beam irradiation influenced the thermal stability and thermal shrinkage/expansion behavior and the behavior depended on the electron beam intensity.

Microstructural Evolution and Recrystallization Behavior Traced by Electron Channeling Contrast Imaging

  • Oh, Jin-Su;Yang, Cheol-Woong
    • Applied Microscopy
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    • v.48 no.4
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    • pp.130-131
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    • 2018
  • Electron channeling contrast imaging (ECCI) is one of the imaging techniques in scanning electron microscopy based on a variation in electron backscattering yield depending on the direction of the primary electron beam with respect to the crystal lattice. The ECCI provides not only observation of the distribution of individual grains and grain boundaries but also identification of the defects such as dislocations, twins, and stacking faults. The ECCI at the interface between recrystallized and deformed region of shot peening treated nickel clearly demonstrates the microstructural evolution during the recrystallization including original grain boundaries, and thus can provide better insight into the recrystallization behavior.

Electron Behavior in MIM Structures of LB Ul Ira-thin Films (LB 초박막 MIM 구조에서의 전자이동)

  • 권영수;강도열;국상훈
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1993.11a
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    • pp.105-108
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    • 1993
  • Behavior of electron in polyimide LB films of Al/polyimide LB films/Au (MIM) structures is reported in the present paper. From experimental results, it is known that there is a process where electron moves from Au electrode to Al electrode through LB film. And the electrons are presumed to move by diffusion since the direction is opposite to electric field.

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Solvatochromism, Aggregation and Photochemical Properties of Fullerenes, $C_{60} and C_{70}$, in Solution

  • Nath, Sukhendu;Pal, Haridas;Sapre, Avinash.V.;Mittal, Jai.P.
    • Journal of Photoscience
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    • v.10 no.1
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    • pp.105-119
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    • 2003
  • Fullerenes, $C_{60}$ and $C_{70}$, display interesting physicochemical properties in solutions, especially due to their unique chemical structures and their good electron accepting abilities. Solubility of fullerenes in different organic solvents and their unusual solvatochromic behavior, the ability of the fullerenes to form aggregates in solutions, and their electron transfer and charge transfer interactions with variety of electron donors, are the subjects of extensive research activities for more than one decade. Many research groups including ours have contributed substantially in the understanding of the solvatochromism, aggregation behavior, and the photoinduced electron transfer and charge transfer chemistry of fullerenes, in condensed phase. Present article is aimed to summarize the important results reported on the above aspects of fullerenes, subsequent to the earlier report from our group (D.K. Palit and J.P. Mittal, Full. Sci. & Tech. 3, 1995, 643-659).)., 643-659)..

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Study of Electron Injection of Pentacene Field Effect Transistor with Au Electrodes by C-V and SHG Measurements

  • Lim, Eun-Ju;Manaka, Takaaki;Tamura, Ryosuke;Ohshima, Yuki;Iwamoto, Mitsumasa
    • Transactions on Electrical and Electronic Materials
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    • v.9 no.4
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    • pp.151-155
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    • 2008
  • Using pentacene field effect transistors (FETs) with Au source and drain electrodes, electron injection from the Au electrodes into the pentacene was investigated. The capacitance-voltage (C-V) and optical second harmonic generation (SHG) measurements were employed. Electron injection from the Au electrodes was suggested by the hysteresis behavior with the C-V characteristics and slowly decaying SHG signal under DC biasing, A mechanism of hole-injection assisted by trapped electrons is proposed. To confirm electron injection process, light-emitting behavior under the application of AC applied voltage was observed.

Microscopic Investigation of the Strain Rate Hardening for Polycrystalline Metals (철강재료 변형률속도 경화의 미시적 관찰)

  • Yoon, J.H.;Park, C.G.;Kang, J.S.;Suh, J.H.;Huh, M.Y.;Kang, H.G.;Huh, H.
    • Transactions of Materials Processing
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    • v.17 no.1
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    • pp.46-51
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    • 2008
  • Polycrystalline materials such as steels(BCC) and aluminum alloys(FCC) show the strain hardening and the strain rate hardening during the plastic deformation. The strain hardening is induced by deformation resistance of dislocation glide on some crystallographic systems and increase of the dislocation density on grain boundaries or inner grain. However, the phenomenon of the strain rate hardening is not demonstrated distinctly in the rage of $10^{-2}$ to $10^2/sec$ strain rate. In this paper, tensile tests for various strain rates are performed in the rage of $10^{-2}$ to $10^2/sec$ then, specimens are extracted on the same strain position to investigate the microscopic behavior of deformed materials. The extracted specimens are investigated by using the electron backscattered diffraction(EBSD) and transmission electron microscopy(TEM) results which show the effect of texture orientation, grain size and dislocation behavior on the strain rate hardening.