• Journal of the Korean Vacuum Society
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• v.10 no.1
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• pp.112-118
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• 2001

Magnetic field is commonly used in low temperature processing plasmas to enhance the performance of the plasma reactors. E$\times$B magnetron or surface multipole configuration is the most popular. However, the properties of capacitively coupled rf plasma confined by axial static magnetic field have rarely been studied. With these background, the effect of magnetic field on the characteristics of capacitively coupled 13.56 MHz/40 KHz argon plasma was studied, Ion saturation current, electron temperature and plasma potential were measured by Langmuir probe and emissive probe. At low pressure region (~10 mTorr), ion current increases by a factor of 3-4 due to reduction of diffusion loss of charged particles to the wall. Electron temperature slightly increases with magnetic field for 13.56 MHz discharge. However, for 40 KHz discharge, electron temperature decreased from 1.8 eV to 0.8 eV with magnetic field. It was observed that the magnetic field induces large temporal variation of the plasma potential. Particle in cell simulation was performed to examine the behaviors of the space potential. Experimental and simulation results agreed qualitatively.

• Textile Coloration and Finishing
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• v.1 no.1
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• pp.7-18
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• 1989

The distinguishing characteristic of the glow discharge is that chemical reaction induced by partially ionized gases are limited only to the substrate surface. Most studies have been done on the plasma etching and polymerization. The graft polymerization in vapour phase by cold plasma has been rarely investigated. In this study the system of tub3ar reaction chamber with capacitively coupled electrode of alternative current of 60 Hz was employed for the graft polymerization. The graft polymerization of Acylic Acid(AA) onto the poly (ethylene terephthalate) (PET) was carried out by treatment of PET film and fabric by cold plasma (glow discharge of argon gas), followed by the supply of AA vapour. The graft yield was about 1 wt%. The surface property was determined by contact angle, the surface tension was evaluated by zisman’s plot and equation of surface tension mesurement. The results were as follows: 1. In order to obtain lower contact angle, it was effective to avoid the vicinity of electrodes for a setting position of substrate. 2. Contact angle affected on the monomer pressure and its duration of exposure to the acid vapour. 3. Polymer radical formation was influenced by the changes of the value of current density and plasma treatment time. 4. Total surface tension of plasma grafted PET film increased. With an increase in the carboxylic acid content, the dispersion force decreased, while, the polar force and hydrogen bonding force increased. 5. The contact angle decreased from $75^\circ$ to around $30^\circ$ by plasma grafting. There was no ageing effect on the contact angle after 4 months.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.540-543
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• 2011

This work is devoted to an experimental investigation on conceptual design of dual consecutive stage micro plasma thruster (${\mu}PT$). Optimization study on the thruster configuration has been performed for various electrode gap distances from 1 mm to 2 mm and the hole diameter from 0.3 mm to 2 mm depending on desired operating conditions and corresponding nozzle design requirement. The operation of ${\mu}PT$ at low pressure from $10^{-1}$ Torr to $10^{-4}$ Torr and at various argon flow rates ranging from 5 sccm to 300 sccm has been studied to understand the physic of plasma and the gas dynamics in details. The specific impulse can reach up to 3000-4000 seconds at low power consumptions from 1 to 5 W. Image of exhaust plume from ${\mu}PT$ will be provided and electrical characteristics is also mentioned in this paper.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.3
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• pp.238-245
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• 2017

Mg-Ni nanoparticles were synthesized by a physical vapor condensation method (DC arc-discharge) in a mixture of argon and hydrogen atmosphere, using compressed mixture of micro powders as the raw materials. The crystal phases, morphology, and microstructures of nanoparticles were analyzed by means of X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). It was found that the intermetallic compounds of $Mg_2Ni$ and $Mg_2Ni$ formed with existence of phases of Mg, Ni, and MgO in Mg-Ni nanoparticles. After one cycle of hydrogen absorption/desorption process (activation treatment), Mg-Ni nanoparticles exhibited excellent hydrogen absorption properties. $Mg_2Ni$ phase became the main phase by aphase transformation during the hydrogen treatments. The phenomenon of refinement of grain size in the nanoparticle was also observed after the hydrogen absorption/desorption processes, which was attributed to the effect of volume expansion/shrinkage and subsequent break of nanoparticles. Maximum hydrogen absorption contents are 1.75, 2.21 and 2.77 wt.% at 523, 573 and 623 K, respectively.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1803-1805
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• 1998

Electron temperature, electron density and electron energy distribution function were measured in Radio-Frequency Inductively Coupled Plasma(RFICP) using a probe method. Measurements were conducted in argon discharge for pressure from 10 mTorr to 40 mTorr and input rf power from 100W to 600W and flow rate from 3 sccm to 12 sccm. Spatial distribution electron temperature and electron density and electron energy distribution function were measured for discharge with same aspect ratio(R/L=2). Electron temperature was found to depend on pressure, but only weakly on power. Electron density and electron energy distribution function strongly depended on both pressure and power. Electron density and electron energy distribution function increased with increasing flow rate. Radial distribution of the electron density and electron energy distribution function were peaked in the plasma center. Normal distribution of the electron density electron energy distribution function were peaked in the center between quartz plate and substrate. These results were compared to a simple model of ICP, then we found out the generation mechanism of Radio-Frequency Inductively Coupled Plasma.

• Elastomers and Composites
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• v.39 no.1
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• pp.3-11
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• 2004

Plasma treatment is frequently used to increase surface functionality and surface activity. It enables to improve various surface properties such as catalytic selectivity, printability, and interfacial adhesion between various materials. Surface or the ethylene-vinyl acetate (EVA) is exposed under an atmospheric pressure plasma torch (APPT), generated by dielectric barrier discharge (DBD), and the treated surfaces are systemically investigated. Argon, air, and oxygen are used as a processing gas. Properties of the treated EVA surfaces are investigated by the zeta-potential measurements and surface free energies. It is shown that the plasma treatment leads to a drastic increase of surface functional groups of EVA, as the increase of its adhesion energy ($G_{IC}$). Therefore, it is concluded that the APPT process is an effective means to improve adhesion of EVA and polyurethane (PU).

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.4
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• pp.82-86
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• 1999

Electron Energy Distribution Function(EEDF) were treasured In Radio-Frequency Inductively Coupled Plasma(RFlCP) using a probe rrethocl Measurerrents were conducted in argon discharge for pressure from 10[mTorr] to 4O[mTorr] and input rf power from 100[W] to 600[W] and flow rate from 3[sccm] to 12[sccm]. Spatial distribution of electron energy distribution function were measured for discharge with same aspoct ratio (R/L=2). Electron energy distribution function strongly depended on both pressure and power. Electron energy distribution function increased with increasing flow rate. Radial distribution of the electron energy distribution function were peaked in the plasma center. Normal distribution of the electron energy distribution function were peaked in the center between quartz plate and substrate. From the results, we can find out the generation mechanism of Radio Frequency Inductively Coupled Plasma. And these results contribute the application of a simple Inductively Coupled Plasma(ICP).a(ICP).

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.211-216
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• 2000

In this paper, experimental investigations were carried out to remove NOx, SOx simultaneously from a simulated combustion flue gas [$NO(0.02%)-SO_2(0.08%)-CO_2-Air-N_2$] by using a pulse corona induced plasma chemical processing. Discharge domain of wire-cylindrical plasma reactor was separated from a gas flow duct to avoid unstable discharge by aerosol particle deposited on discharge electrode and grounded electrode. The NOx, SOx removal was experimentally investigated by a reaction induced to ammonium nitrate, ammonium sulfate using a low price of aqueous NaOH solution and a small quantity of ammonia. Volume percentage of aqueous NaOH solution used was 20% and $N_2$ flow rate was $2.5{\ell}/min$ for bubbling aqueous NaOH solution. Ammonia gas(l4.82%) balanced by argon was diluted by air and was introduced to a main simulated flue gas duct through $NH_3$ injection system which was in downstream of reactor. The $NH_3$ molecular ratio(MR) was determined based on [$NH_3$] and [$NO+SO_2$]. MR is 1.5. The NOx removal rates increased in the order of DC, AC and pulse, but SOx removal rates was not significantly effected by source of electricity. The NOx removal rate slightly decreased with increasing initial concentration. but SOx removal rate was not significantly affected by initial concentration. The NOx, SOx removal rates decreased with increasing gas flow rate.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.611-615
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• 2004

In recent, there have been several developments in lamp technology that promise savings in electrical power consumption and improved quality of the lighting space. Above all, Electrodeless fluorescent lamp is the removal of internal electrodes and heating filaments that are a light-limiting factor of conventional fluorescent lamps. The electrodeless fluorescent lamp is intended as a high efficacy replacement for the incandescent reflector lamp in many applications. Therefore, the electrodeless fluorescent lamps is substantially higher than that of conventional fluorescent lamps and last up to 60,000 hours. In this paper, electron temperature and electron density were measured in a radio-frequency inductively coupled plasma using a Langmuir probe method for emission characteristics. Measurement was conducted in an argon discharge for pressure from 10 [mTorr] and input RF power 100 [W] to 150 [W]. As for the electron density, a electron temperature was more distinguished for a emission characteristic. The results of ideal may contribute to systematic understanding of a electrodeless fluorescent lamps of emission characteristics.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.57-60
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• 2008

Purpose: The radial speed of plasma current sheath was measured at the plasma focus apparatus. Methods: The measurement was used to time-resolved spectroscopic method and Rogowski coils. Results: Radial current sheath speed was measured with $10^5$ cm/s at Helium and Argon pressure between 5 to 100 torr and discharging voltage of 15 kV. When the gas pressure was increased, the current sheath speeds were decreased. Conclusions: At the optimum condition of plasma focus apparatus, the radial speed is guessed $10^7$ cm/s as a results of the measurement of current sheath speed.