• 한국융합학회논문지
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• 제12권1호
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• pp.243-250
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• 2021

이온화된 기체인 플라즈마의 의료분야에서 적용은 현재 주로 살균분야에 국한되어 적용되고 있지만 바이오플라즈마기술의 등장으로 그 응용범위가 확대되고 있는 실정이다. 또한, 인체에 직접 조사하거나 비열처리하는 경우에는 정교한 시술을 위해 핸드헬드가 가능한 고밀도 소형화가 요구된다. 변압기로 인한 전자기파 영향이 없고 소형으로 구현이 가능한 형태의 로젠형 압전변압기는 압전효과를 이용한 전기-기계 커플링을 통해 전압변환을 달성하며 상대적으로 에너지밀도를 높일 수 있는 장점으로 휴대용 플라즈마 발생장치에 이용되고 있다. 본 논문에서는 로젠형 압전변압기의 등가회로를 이용한 모델링을 수행하고, 의료용으로 적용가능한 형태의 플라즈마 발생장치를 설계 및 제작하였다. 이를 위해 플라즈마 발생 모듈은 12V 입력전원으로 5.8kV의 출력전압을 발생시키도록 하프브리지 커버터 토폴로지 전력변환장치를 적용하여 고전압 동작하도록 설계하였다. 설계를 통해 제작된 프로토타입을 통해 의료용합형 플라즈마 기기로의 활용가능성에 대해 확인하였고, 이러한 연구결과를 통해 플라즈마 제트 또는 직접조사용 등의 다양한 의료기기로서의 역할을 확보할 것으로 사료된다.

• 한국세라믹학회지
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• 제32권3호
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• pp.371-377
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• 1995

Silicon oxide films were grown on single-crystal silicon substrates at low temperatures (25~205$^{\circ}C$) in a low pressure electron cyclotron resonance (ECR) oxygen plasma. The growth rate of the silicon oxide film increased as the temperature increased or the pressure decreased. Also, the thickness of the silicon oxide film increased at negative bias voltage, but not changed at positive bias voltage. The growth law of the silicon oxide film was approximated to the parabolic form. Capacitance-voltage (C-V) and current density-electric field (J-E) characteristics were studied using Al/SiO2/p-Si MOS structures. For a 10.2 nm thick silicon oxide film, the leakage current density at the electric field of 1 MVcm-1 was less than 1.0$\times$10-8Acm-2 and the breakdown field was higher than 10 MVcm-1. The flat band voltage of Al/SiO2/p-Si MOS capacitor was varied in the range of -2~-3 V and the effective dielectric constant was 3.85. These results indicate that high quality oxide films with properties that are similar to those of thermal oxide film can be fastly grown at low temperature using the ECR oxygen plasma.

• Environmental Engineering Research
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• 제24권3호
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• pp.412-417
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• 2019

This paper presents the results of using cold plasma to treat surface water for domestic use purpose. Experimental results showed that cold plasma was an effective method for destroying bacteria in water. After treatment with cold plasma, concentration of coliform and Escherichia coli dramatically reduced. Besides, cold plasma significantly removed water odor, increased dissolved oxygen and decreased the concentration of chemical oxygen demand. However, cold plasma significantly raised the concentration of nitrite and nitrate. Other disadvantages of treating with cold plasma were conductivity increase and pH reduction. Pretreatment steps of coagulation, flocculation, sedimentation and sand filtration followed by disinfection with cold plasma exhibited a high efficiency in surface water treatment. All parameters of surface water after treatment by using the prototype satisfied with the allowance standard of domestic water quality.

• 전력전자학회논문지
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• 제14권1호
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• pp.72-81
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• 2009

본 논문에서는 대기압 플라즈마 발생용 정현파펄스형 교류 전원 장치에 대한 연구를 진행하였다. 정현파펄스형 전원장치는 기존의 LC공진을 이용한 교류 전원장치보다 높은 dv/dt를 갖게 되므로 안정적인 플라즈마 공급이 가능하며 펄스형에 비해 고조파 노이즈가 적고, 정전류 턴온-영전압 턴오프 형태로 동작하므로 매우 높은 효율을 갖는다. 또한 플라즈마 점화 기능을 강화하고 안정적인 전압제어를 위해 3상 부스트형 컨버터를 입력단에 사용하여 입력 역률이 매우 높은 시스템을 구성할 수 있다. 실험실 수준의 10kW부하시설을 사용하여 본 연구의 결과를 입증하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2092-2094
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• 2000

As a next generation lithography (NGL) technology for VLSI semiconductor fabrication, electron beam, ion beam, X-ray and extreme ultraviolet(EUV) are considered as possible candidates. Among these methods, EUV lithography(EUVL) is thought to be the most probable because it is easily realized by improving current optical lithography technology. In order to set EUV radiation which can be applied to EUVL, it is essential to generate very high density and high temperature plasma stably. The method using a pulse power laser and a high voltage pulse discharge is commonly used to accomplish such a high density and high temperature plasma. In this paper we review the recent trends of the EUV generation technique by high density and high temperature plasma.

• Journal of Korean Society for Atmospheric Environment
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• 제17권E3호
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• pp.91-99
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• 2001

Plasma reactor was used to generate a high potential difference between two surfaces of concentric pyrex tubes by electrical current. The annular gap of the reactor was calculated by trial and error from the breakdown voltage equation and set at 0.45 cm. The overall objective of this research was to know the effects of the frequency, humidity, and residence time on the formation of nitrogen oxides in a plasma reactor. The primary voltage varied from 50 to 90 volts and the frequency was varied in increments of 10 Hz from 60 to 650 Hz at the primary voltage of 90. The increase in the secondary voltage was not linear but exponential at high frequencies. At a maximum concentration of about 745 ppm, the frequency and secondary voltage was 600 Hz and 4,200 volts, respectively. All tests for the effects of humidity on NO$_{x}$ production were performed at the optimal setting of 90 colts and 600 Hz frequency. Since the NO$_{x}$ production was not an one dimensional phenomenon, competing reactions were assumed to occur in the discharge chamber. The sharp peak concentration of 1,810 ppm was observed at 38% of relative humidity, The enhanced production was choked off, and the production rate rapidly dropped to 3 ppm at above 40% of relative humidity. It is assumed that the corona attacks the most vulnerable molecules in the reaction chamber before attacking other more lightly bonded molecules, possibly at humidities above 38% and the optimized 90 volt setting. Thus, there was not enough energy left after attacking all water molecules to decompose an appreciable amount of $N_2$. If nitrogen breakdown does not occur, then oxides of nitrogen are not likely to be produced.ced.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.723-727
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• 2004

A new high-performance and low cost single switch energy recovery display driver for an AC plasma display panel (PDP) is proposed. Since it is composed of only one auxiliary power switch, two small inductors, and eight diodes compared with the conventional circuit consisting of four auxiliary power switches, two small inductors, eight power diodes, and two external capacitors, it features a much simpler structure and lower cost. Nevertheless, since the rootmean-square (RMS) value of the inductor current is very small, it also has very desirable advantages such as n low conduction loss and high efficiency. Furthermore, there are no serious voltage-drops caused by the large gas-discharge current with the aid of the discharge current compensation, which can also greatly reduce the current flowing through power switches and maintain the panel to light at n lower sustaining voltage. In addition, all main power switches are turned on under the zero-voltage switching (ZVS) and thus, the proposed circuit has a improved EMI, increased reliability, and high efficiency. Therefore, the proposed circuit will be well suited to the wall hanging PDP TV. To confirm the validity of the proposed circuit, circuit operations, features,and design considerations are presented and verified experimentally on a 6-inch PDP, 50kHz-switching frequency, and sustaining voltage 141V based prototype.

• KIEE International Transactions on Electrophysics and Applications
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• 제5C권5호
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• pp.183-190
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• 2005

In order to drive the high-density plasma displays, a high-speed driving technology must be researched. In this experiment, the relationship between the width of the address electrode and high-speed driving is analyzed using the Vt close curve and the panel structure for high-speed driving is proposed. In addition we show that the wider the width of the address electrode is, the narrower the width of the scan pulse becomes. Therefore, we could achieve the minimum data voltage of 50.1V at a scan pulse width of $1.0/{\mu}s$ and a ramp voltage of 210V at an address electrode width of $180/{\mu}m$ for the high-speed driving 4-inch test PDP.

• 한국추진공학회지
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• 제2권2호
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• pp.1-13
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• 1998

반도체 브릿지(Semiconductor bridge, SCB)에 30$\mu\textrm{s}$ 이내의 짧은 시간 동안 펄스 형태의 에너지를 공급할 경우 SCB는 화약을 발화시킬 수 있는 플리즈마를 생성한다. 초고속 카메라를 이용하여 플라즈마의 형태를 관찰하였고 발생시간, 지속 시간 등을 알아보았다. 공급된 에너지의 양이 많을수록 플라즈마는 빨리 생성되고 그 크기도 비례적으로 증가하였다. SCB 작동시 브릿지 양단의 전압 변화를 기록하여 초고속 카메라 상과 비교함으로써 전압 곡선의 변화를 해석하였다.

• Applied Science and Convergence Technology
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• 제26권6호
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• pp.195-200
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• 2017

A mobile lab kart for plasma training is developed with a high vacuum pumping system, vacuum gauges and a glass discharge tube powered by a high voltage transformer connected to a household 60 Hz line. A numerical model is developed by using a commercial multiphysics software package, CFD-ACE+ to analyze the experimental data. Simulations for argon and nitrogen were carried out to provide fundamental discharge characteristics. Variations of the kart configuration were demonstrated: a glass tube with three electric probes, optical emission spectrometer attachment and infra red thermal imaging system to give more detailed analysis of the discharge characteristics.