• Title/Summary/Keyword: hollow cathode

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A study of the hollow cathode discharge (HOLLOW CATHODE DISCHARGE의 방전 특성 연구)

  • Cho, S.M.;Seo, Y.W.;Kim, M.J.;Whang, K.W.
    • Proceedings of the KIEE Conference
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    • 1989.11a
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    • pp.139-141
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    • 1989
  • The characteristics of the hollow cathode discharge were investigated. Temperature distribution of the hollow cathode was investigated and I-V curves of the hollow cathode discharge were obtained. In this paper variables are chamber pressure, Ar gas flow rate injected through the cathode tube and the gap distance between cathode and anode. The inter electrode electron temperature and density were measured by Langmuir probe.

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A Study on Large Area Black Silicon Solar Cell Using Radio-Frequency Multi-Hollow cathode Plasma System (Radio Frequency Multi-Hollow Cathode 플라즈마 시스템을 이용한 대면적 블랙 실리콘 태양전지에 관한 연구)

  • 유진수;임동건;양계준;이준신
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.11
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    • pp.496-500
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    • 2003
  • A low-cost, large area, random, maskless texturing scheme independent of crystal orientation is expected to significantly impact terrestrial photovoltaic technology. We investigated silicon surface microstructures formed by reactive ion etching (RIE) in Multi-Hollow cathode system. Desirable texturing effect has been achieved when radio-frequency (rf) power of about 20 Watt per one hollow cathode glow is applied for our RF Multi-Hollow cathode system. The black silicon etched surface shows almost zero reflectance in the visible region as well as in near IR region. The etched silicon surface is covered by columnar microstructures with diameters from 50 to 100 nm and depth of about 500 nm. We have successfully achieved 11.7% efficiency of mono-crystalline silicon solar cell and 10.2% multi-crystalline silicon solar cell.

Measurement of Optogalvanic Signal in Hollow Cathode Discharge Tube (Hollow Cathode Discharge Tube에서의 광검류 신호 측정)

  • Lee, Jun-Hoi;Yoon, Man-Young;Kim, Song-Kang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.874-877
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    • 2002
  • The optogalvanic signals were measured using hollow cathode discharge tube with argon as buffer gas at change of discharge currents. A change of ionization rate due to electron collision causes an increase or decrease of the electric conductivity. This change in electric conductivity generates the optogalvanic signal. We conclude that optogalvanic signal has close relation with the lowest metastable atoms density at low current.

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Atmospheric Pressure Micro Plasma Sources

  • Brown, Ian
    • Journal of the Korean institute of surface engineering
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    • v.34 no.5
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    • pp.384-390
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    • 2001
  • The hollow cathode discharge is a kind of plasma formation scheme in which plasma is formed inside a hollow structure, the cathode, with current to a nearby anode of arbitrary shape. In this scheme, electrons reflex radially within the hollow cathode, establishing an efficient ionization mechanism for gas within the cavity. An existence condition for the hollow cathode effect is that the electron mean-free-path for ionization is of the order of the cavity radius. Thus the size of this kind of plasma source must decrease as the gas pressure is increased. In fact, the hollow cathode effect can occur even at atmospheric pressure for cathode diameters of order 10-100 $\mu\textrm{m}$. That is, the "natural" operating pressure regime for a "micro hollow cathode discharge" is atmospheric pressure. This kind of plasma source has been the subject of increasing research activity in recent years. A number of geometric variants have been explored, and operational requirements and typical plasma parameters have been determined. Large arrays of individual tiny sources can be used to form large-area, atmospheric-pressure plasma sources. The simplicity of the method and the capability of operation without the need for the usual vacuum system and its associated limitations, provide a highly attractive option for new approaches to many different kinds of plasma applications, including plasma surface modification technologies. Here we review the background work that has been carried out in this new research field.

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Development of a Plasma Gun System for Ion Plating with Long Lifetime (이온 플레이팅용 장수명 플라즈마 건 장치의 개발)

  • Choi, Young-Wook
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.1
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    • pp.78-81
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    • 2008
  • A hollow cathode which has extremely stable discharge characteristic has been developed. This is composed of the two separated lanthanum hexaboride(LaB6) of a disk type in the tube as the electron emitters. The way of design is of great advantage to extend the surface discharge area of the LaB6, which is also useful for optimal fixing of the LaB6. The hollow cathode is capable of producing 30 kW(100 V, 300 A) of power continuously. Because the generated plasma beam with the high temperature(above $3000^{\circ}C$) from the hollow cathode passes through the center hole of the two intermediate electrodes, it is designed with the high temperature material of the tungsten and the suitable structure of the water cooling. The combinations of the hollow cathode and the two intermediate electrodes are practically useful for the ion plating plasma beam source.

A Study on the Nitriding of Sintered Metallic Components by Hollow Cathode Discharge (할로우 캐소드 방전에 의한 금속소결부품의 질화처리에 관한 연구)

  • Kim, Y.C.;Han, C.S.
    • Journal of the Korean Society for Heat Treatment
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    • v.25 no.2
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    • pp.80-84
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    • 2012
  • An apparatus was constructed to nitrify small metallic sintered components by using a hollow-cathode discharge plasma method. A stainless steel basket, which contains a sintered part to be nitrified, is potentially grounded and serves as hollow-cathode electrode. Hollow-cathode plasma was produced by supplying the positive voltage to the anode. In this study sintered carbon iron and stainless steel were used as testing specimens. It was shown that an effective nitrifying took place by controlling the total pressure of nitrogen and hydrogen gas and applied voltage.

The Dielectric Barrier micro-hollow cathode structure and its upper pD limitation in alternative current driving for flat panel light source (광원을 위한 AC구동 유전체장벽 미세공음극 구조와 상한 pd 제한조건)

  • Park K. W.;Lee T. I.;Jegal J. P.;Baik H. K.
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2005.05a
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    • pp.45-47
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    • 2005
  • The Dielectric Barrier micro-hollow cathode structure and it's upper pD limitation are investigated for determining of optimum hollow cathode discharge condition. In experiment, discharge is sustained by AC diriving and investigated gas is pure Xe. From Experiment, Optimum pD range is lower than 0.72 torr.cm at pure Xe and Cu cathode.

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Fluid Flow in Plasma Deposition Reactor and Characteristics of Titanium Oxide Films Deposited at Room Temperature (플라즈마 증착 반응기에서 유체흐름과 상온에서 증착된 티타늄 산화막 특성)

  • Jung, Ilhyun
    • Applied Chemistry for Engineering
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    • v.18 no.5
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    • pp.438-443
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    • 2007
  • Titanium oxide films were deposited by the HCP (hollow cathode plasma) reactor at room temperature. With results of simulation about HCP reactor, the temperature profile is uniform on substrate regardless of the heat generation at cathode. The velocity profile on the surface of substrate is more uniform with increasing the gap between cathode and substrate, and surface roughness was decreased with increasing the gap between cathode and substrate. We could confirm that the composition of oxide increased with RF-power, and the ratio of O to Ti in the films was about 2 : 1 at RF-power of 240 watt and distance between cathode and substrate of 3 cm.