• Applied Science and Convergence Technology
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• v.26 no.6
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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.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.5
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• pp.60-67
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• 2005

The superposed discharge type ozonizer of high ozone concentration using vacuum discharge tube has been designed and manufactured. It consists of three electrodes(central electrode, internal electrode, and external electrode) and one discharge gap(discharge gap between internal electrode and external electrode), is a superposed silent discharge type ozonizer for which the AC high voltages applied to the central electrode within discharge tube and the internal electrode has a $180{[^\circ]}$ phase difference and for which the external electrode is a ground. Ozone is generated by overlapping silent discharge between central electrode and external electrode, and silent discharge between internal electrode and external electrode. At the moment, discharge characteristics and ozone generation characteristics were investigated in accordance with vacuum of discharge tube, discharge power of ozonizer, and quantity of supplied oxygen gas. In consequence, high ozone concentration can be obtained 8840[ppm].

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.8
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• pp.94-101
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• 2005

The silent discharge type ozonizer with three electrodes(central electrode, internal electrode, and external electrode) and one discharge gap(discharge gap between internal electrode and external electrode) has been designed and manufactured. It is a silent discharge type ozonizer for which the AC high frequency voltages applied to the central electrode within vacuum discharge tube and the internal electrode for which the external electrode is a ground Ozone is generated by silent discharge in discharge gap. At the moment, discharge characteristics and ozone generation characteristics were investigated in accordance with vacuum of discharge tube, frequency of AC power source, discharge power of ozonizer, and quantity of supplied oxygen gas. In consequence, ozone characteristics proportional to vacuum of discharge tube and frequency of AC power source. The maximum value of ozone can be obtained 7,700[ppm], 460[mg/h] and 70[g/kwh].

• Journal of the Korean Vacuum Society
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• v.11 no.2
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• pp.119-126
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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 change of the lowest metastable atoms density at low current.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.371-372
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• 2008

In this paper, we experimentally investigated discharge phenomena inside vacuum interrupter at 1 to 20 Torr to simulate the vacuum leakage. We used glass type of vacuum interrupter where the internal pressure and the type of gasses can be varied according to requirement. The experiment is conducted under ac applied voltage and the experimental circuit is constructed to simulate the actual circuit used in cubical type insulated switchgear. We used two types of gases such as air and $SF_6$. The use of glass type vacuum interrupter allowed us to measure discharges occurring in vacuum interrupter optically. We measured and discussed the discharge occurring in both gases with a current transformer and ICCD camera. We also revealed that electromagnetic wave spectra emitted by the discharge have same frequency range for both gasses.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.6
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• pp.230-235
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• 2003

In this paper, a superposed discharge type ozonizer with an internal dielectric that can be made into a vacuum tube has been designed and fabricated. Ozone generation and discharge characteristics have been investigated in accordance with output voltage of power supply, flow-rate, discharge power and vacuum of inside internal dielectric. Pure oxygen was used as the supply gas of the ozonizer. Ozone concentration and ozone generation are gradually increased when discharge power is increased at the same flow-rate and they are both proportional to the vacuum level. As such, the maximum ozone concentration of 8840 ppm was obtained at vacuum 0.1 Torr and flow-rate 0.5 $\ell$/min.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.12
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• pp.568-572
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• 2003

A longitudinal discharge heated copper vapor laser with internal diameter 28 mm and discharge length 1.3 m has been constructed and tested. At the discharging voltage 15.2 kV, pulse repetition rate 10 kHz, buffer gas pressure 40 mbar, and internal temperature of the laser plasma tube $1520^{\circ}C$, it delivers more than 30 W average laser outputs.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.512-513
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• 2013

Space and time resolved discharge images from an atmospheric pressure non-thermal Ar plasma jet have been observed by a ICCD camera to investigate the electron temperatures. Plasma jet device consisting of a syringe electrode inserted into a glass tube has been introduced. A high voltage is applied to the syringe electrode. The syringe needle has an outer diameter of 1.8 mm, an inner diameter of 1.3 mm, and a total length of 39.0 mm. The needle is inserted into a glass tube of outer diameter 2.4 mm and inner diameter 2.0 mm, and a total length of 80.0 mm. The Ar plasma propagation speed on the cathode has been shown to be about 2.1 km/s at input discharge voltage of 3.6 kV, discharge current of 19.9 mA and driving frequency of about 45 kHz. Particularly, the electron temperature in plasma jet were found to be about 1.8 eV at input discharge voltage of 3.6 kV and driving frequency of 45 kHz, respectively.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.400-403
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• 2002

The fundamental experiments for measuring soft x-ray characteristics from the vacuum capillary are described. These experiments were primarily performed in order to generate line spectra such as x-ray lasers. The generator consists of a high-voltage power supply, a polarity-inversion ignitron pulse generator, a turbo-molecular pump, and a radiation tube with a capillary. A high-voltage condenser of 200 nF in the pulse generator is charged up to 20 kV by the power supply, and the electric charges in the condenser are discharged to the capillary in the tube after closing the ignitron. During the discharge, weakly ionized plasma forms on the inner and outer sides of a capillary. In the present work, the pump evacuates air from the tube with a pressure of about 1 mPa, and a demountable capillary was developed in order to measure x-ray spectra according to changes in the capillary length. In this capillary, the anode (target) and cathode elements can be changed corresponding to the objectives. The capillary diameter is 2.0 mm, and the length is adjusted from 1 to 50 mm. When a capillary with aluminum anode and cathode electrodes was employed, both the cathode voltage and the discharge current almost displayed damped oscillations. The peak values of the voltage and current increased when the charging voltage was increased, and their maximum values were -10.8 kV and 4.7 kA, respectively. The x-ray durations observed by a 1.6 ${\mu}$m aluminum filter were less than 30 ${\mu}$s, and we detected the aluminum characteristic x-ray intensity using a 6.8 ${\mu}$m aluminum filter. In the spectrum measurement, two sets of aluminum and titanium electrodes were employed, and we observed multi-line spectra. The line photon energies seldom varied according to changes in the condenser charging voltage and to changes in the electrode element. In the case where the titanium electrode was employed, the line number decreased with corresponding decreases in the capillary length. Compared with incoherent visible light, these rays from the capillary were diffracted and diffused greatly after passing through two slits.

• Journal of the Korean Vacuum Society
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• v.22 no.3
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• pp.111-118
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• 2013

The influence of gas flow on the plasma generation in the atmospheric plasma jet is described with the theory of hydrodynamics. The plasma discharge is affected by the gas-flow streams with Reynolds number (Re) as well as the gas pressure with Bernoulli's theorem according to the gas flow rate inserted into the glass tube. The length of plasma column is varied with the flow types such as the laminar flow of Re<2,000 and the turbulent flow of Re>4,000 as it has been known in a general fluid experiments. In the laminar flow, the plasma column length is increased as the increase of flow rate. Since the pressure in the glass tube becomes low as the increase of flow velocity by the Bernoulli's theorem, the breakdown voltage of plasma discharge is reduced by the Paschen's law. Therefore, the plasma length is increased as the increasing flow rate with the fixed operation voltage. In the transition of laminar and turbulent flows, the plasma length is decreased. When the flow becomes turbulent as the flow rate is increasing, the plasma length becomes short and the discharge is shut down ultimately. In the discharge of laminar flow, the diameter of plasma beam exposed on the substrate surface is kept less than the glass diameter, since the gas flow is kept to the distinct distance from the nozzle of glass tube.