• 한국진공학회지
• /
• 제5권1호
• /
• pp.85-92
• /
• 1996

The external electricla characteristics of helicon wave plasmas were measured over a wide range of RF power and magnetic filed. External parameters. such as antenna voltage , current, phase shift, and interanl parameter, electron density were measured at 7MHz, 1mTorr Ar discharge . The equivalent discharge resistance and reactance, and the power transfer efficiency were calculated through these measurements. There are a helicon mode which produces high density plasma by helicon wave and a lowmode which produces low density plasma by capaictive electric field. In case of the helicon mode, the anternna voltage and current were lower than those of the low-mode. The phase difference between voltage and current decreased suddenly at the transition point from the low-mode to the helicon mode. Equivalent resistance and power efficiency increased and reactance decreased suddenly at the transition point. These results mean that the power transperred to plasma and the nutual coupling between the antenna and plasma increase as the mode changes from the low-mode to the helicon mode.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1989년도 하계종합학술대회 논문집
• /
• pp.426-428
• /
• 1989

As a first phase of plasma study intended for semiconductor processing research, we have studied the discharge phenomena. In particular, we have obtained a specific formula for the breakdown voltage as a function of the neutral state pressure of reactive gases. Our experimental results with H2,O2,Ar,CF4 seem ro verify this formula. In addition we find the voltage levels for various gases in the descending order of CF4>O2=Ar>H2 in high pressure region, while H2>CF4>O2>Ar in low pressure region. When H2 and CF4 were mixed, we observe the overall voltage dominated by the gas with lower breakdown volotage.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
• /
• pp.121.1-121.1
• /
• 2014

Recently, much attention has been given to plasma production under liquid and its applications [1]. However, most of plasma production techniques reported so far utilize high voltage dc, ac, rf or microwave power [2], where damage to discharge electrodes and small discharge volume are remained issues. As an alternative of plasma production method under liquid, we have proposed pulsed microwave excited plasma using slot antenna, where damage to the slot electrode can be minimized and plasma volume can be increased. We have also reported improvement of treatment efficiency with use of reduced-pressure condition during the discharge [3]. To realize low pressure conditions in liquid, various alternative technique can be considered. One possible technique is simultaneous injection of microwave power and ultrasonic wave. Ultrasonic wave induces pressure fluctuation with the wave propagation and is so far used for cavitation production in the water. We propose utilization of reduced pressure induced by ultrasonic cavitation for improvement of the plasma production. Correlation between the plasma production and the ultrasonic power will be discussed.

• 조명전기설비학회논문지
• /
• 제21권9호
• /
• pp.7-11
• /
• 2007

The objective of this study is to evaluate the characteristics of a newly proposed high-speed drive method for the gray scale display for high-resolution plasma display panels(PDP). In the experiment it was found that the characteristics of gray scale display are not closely affected by a priming period below 50[${\mu}s$], the width of the priming period, and that it can be driven stably from the brightest sub-field to the darkest sub-field even though a priming discharge is applied to the 1 TV-field only once. Moreover, from the experimental result, the gray scale pattern of 8-bit and 9 sub-fields was stably displayed in the experimental PDP with scan pulses having the pulse width of 0.7[${\mu}s$]. An address voltage margin of about 25[V] and a sustain voltage margin of about 10[V] was obtained.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2006년도 영호남 합동 학술대회 및 춘계학술대회 논문집 센서 박막 기술교육
• /
• pp.82-85
• /
• 2006

As a display becomes large recently, Acquisition of high luminance and Luminance uniformity is becoming difficult in the existing CCFL or EEFL backlight system. So, study for a performance enhancement has enforced. but lamp development of flat type is asked for high luminance and a luminance uniformity security in of LCD and area anger trend ultimately. In this paper, we changed a tip shape of an electrode for production by the most suitable LCD backlight surface light source, and confirmed discharge characteristic along discharge gas pressure and voltage, and confirmed electric field distribution and discharge energy characteristic through a Maxwell 2D simulation. Therefore the discharge firing voltage characteristic showed a low characteristic than a rectangular type and round type in case of electrode which used tip of a triangle type, and displayed a discharge electric current as a same voltage was low.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
• /
• pp.1185-1188
• /
• 2007

The address discharge characteristics by the various scan-low and common-bias voltages are investigated based on measured address discharge time lags and $V_t$ close-curve analysis. The scan-low voltages are changed under the same voltage difference between the X and Y electrodes during an address period. As the voltage difference between the scan and address electrodes is increased during an address period, the address discharge time lag is shortened but the background luminance is increased. It is found that the improved address discharge characteristics is caused by the effect of the higher external applied voltage during an address period than the accumulated wall charges during a reset period and the high background luminance can be prevented by applying an address-bias voltage during a rising-ramp period and low reset voltage.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
• /
• pp.176.2-176.2
• /
• 2013

Property of optical diagnostics for pulse-discharged plasma in liquid and its biological applications to proteins are investigated by making use of high voltage Marx generator. The Marx generator has been consisted of 5 stages, where each charging capacitor is 0.5 ${\mu}F$, to generate a high voltage pulse with rising time of $1{\mu}s$. We have applied an input voltage of 6 kV to the each capacitor of 0.5 ${\mu}F$. High voltage pulsed plasma has been generated inside a polycarbonate tube by a single-shot operation, where the breakdown voltage is measured to be 7 kV, current of 1.2 kA, and pulse width of ~ 1 ${\mu}s$ between the two electrodes of anode-cathode whose material is made of tungsten pin, which are immersed into the liquids. We have investigated the emitted hydrogen lines for optical diagnostics of high voltage pulsed plasma. The emission line of 656.3 nm from $H-{\alpha}$ and 486.1 nm from $H-{\beta}$ have been measured by a monochromator. If we assumed that the focused plasma regions satisfy the local thermodynamic equilibrium conditions, the electron temperature and density of the high voltage pulsed plasma in liquid could be obtained by the Stark broadening of optical emission spectroscopy. For the investigation of the influence of pulsed plasma on biological proteins, we have exposed it onto the proteins such as hemoglobin and myoglobin. The structural changes in these proteins and their analysis have also been obtained by circular dichroism (CD) and ultraviolet (UV) visible spectroscopy.

• Applied Science and Convergence Technology
• /
• 제23권4호
• /
• pp.161-168
• /
• 2014

A real-time monitoring of immersed antenna type inductively coupled plasma (ICP) was done with a homemade 2 dimensional voltage probe array to check the uniformity of the plasma. Measured voltage values with a high impedance voltmeter are close to the floating potential of the plasma. As the substrate carrier was moving into a magnetron sputtering plasma diffusive from a $125mm{\times}625mm$ size cathode, measured results showed reliably separation of plasma into the upper and lower empty space over the carrier. Infra red thermal imaging camera was used to observe the cross corner effect in situ without eroding a target to the end of the usage. 3 dimensional particle trace model was used to analyze the magnetron discharge's behavior.

• 한국환경과학회지
• /
• 제22권7호
• /
• pp.915-923
• /
• 2013

Decomposition of non-biodegradable contaminants such as phenol contained in water was investigated using a dielectric barrier discharge (DBD) plasma reactor in the aqueous solutions with continuous oxygen bubbling. Effects of various parameters on the removal of phenol in aqueous solution with high-voltage streamer discharge plasma are studied. In order to choose plasma gas, gas of three types (argon, air, oxygen) were investigated. After the selection of gas, effects of 1st voltage (80 ~ 220 V), oxygen flow rate (2 ~ 7 L/min), pH (3 ~ 11), and initial phenol concentration (12.5 ~ 100.0 mg/L) on phenol degradation and change of $UV_{254}$ absorbance were investigated. Absorbance of $UV_{254}$ can be used as an indirect indicator of phenol degradation and the generation and disappearance of the non-biodegradable organic compounds. Removal of phenol and COD were found to follow pseudo first-order kinetics. The removal rate constants for phenol and COD of phenol were $5.204{\times}10^{-1}min^{-1}$ and $3.26{\times}10^{-2}min^{-1}$, respectively.

• 전력전자학회논문지
• /
• 제12권5호
• /
• pp.386-393
• /
• 2007

본 논문에서는 CIM(Current Injection Method)을 이용한 charge-pump방식의 plasma backlight용 고압 inverter회로를 제안한다. 고압 inverter에서 에너지 회수회로의 채용은 새로운 시도로서 에너지회수 이외에도 noise에 의한 시스템의 불안정성과 방전안정화에 기여하고 있다. charge-pump방식으로 스위치류의 내압을 저감하므로 cost면에서 매우 유리한 조건을 확립하였으며 CIM(Current Injection Method)방식의 적용으로 high speed 에너지 회수를 가능하게 하였다. 그리고 제안회로의 동작을 모드별로 해석하였으며, 실제 32" 패널에 적용하여 실험함으로써 제안한 회로의 유용성을 입증하였다.