• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1823-1825
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• 2004

Spherically convergent beam fusion device accelerate ions, which are generated between outer anode and inner grid cathode, toward the spherical center. The collision of opposite direction ions give rise to fusion reactions. Spherically convergent beam fusion device is very simple and compact, therefore the device has a potential that is applied to a portable neutron source. An experimental device consist of a 20cm-diameter spherical mesh-type anode and 7cm-diameter open spherical grid cathode and was maintained at a constant pressure of about 1333 Pa by feeding argon gas.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.8
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• pp.729-733
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• 2005

Al electrode for OLED was deposited by FTS (Facing Targets Sputtering) system which can deposit thin films with low substrate damage. The Al thin films were deposited on the cell (LiF/EML/HTL/Bottom electrode) as a function of working gas such as Ar or Ar+kr mixed gas. Also Al thin films were prepared with working gas pressure (1, 6 mTorr). The film thickness and I-V curve of Al/cell were measured and evaluated. In the results, when Al thin films were deposited using pure Ar gas, the turn-on voltage of Al/cell was about 11 V. And using the Ar:Kr($75\%:25\%$) mixed gas, the turn-on voltage of Al/cell decreased to about 7 V.

• The Korean Journal of Ceramics
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• v.4 no.2
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• pp.151-155
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• 1998

The total electrical conductivity, ionic conductivity, and nonstoichimetry of a new cathode material $Y_{1-x}Ca_xFeO_{3-\delta}$ (x=0.1) were measured as functions of temperature ($900\leqT/^{\circ}C\leq1100$) and oxygen partial pressure $(10^{-6}\leqPo_2/atm\leq0.21$). Isothermal variations of these properties with $Po_2$ support that the majority type of ionic defects are anti-Frenkel disorder which, however, has seldom been considered for perovskite-based oxides. The results are discussed in comparison with those reported on similar oxides.

• Journal of the Korean Vacuum Society
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• v.3 no.4
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• pp.382-388
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• 1994

포항가속기연구소에서 사용될 진공게이지 교정시스템이 설계 제작되었다. 이 교정시스템은 동적 교정방법으로 설계되었으며 transfer standard 로서 spinning rotor gauge를 사용하였다. 포항가속기의 저장리에 사용될 모든 진공게이지는 교정시스템으로 교정을 하여 사용할 것이며, 주로 교정할 게이지로 는 Bayard-Alpert(BA) nude ionization gauge와 cold cathode gauge등이 있다. 본 논문에서는 포항가속 기의 진공게이지 교정시스템에 대해서 소개를 하였고 현재까지 BA nude ioni-zation gauge 6대 extractor gauge 1대 high pressure gauge 1대와 cold cathode gauge 5대를 10-4에서 10-4 Torr 범위내 에서 교정하여 그 결과를 보였다.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1717-1719
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• 2000

DLC films are deposited by using an FCVA deposition system with a mirror-type magnetic field configuration. Permanent magnets and: magnetic yokes around the cathode have been observed to enhance the mobility of arc spots on the cathode and the stability of arc plasma, Effects of reactor pressures and substrate biases on structural properties of DLC films deposited are investigated. The results show that the highest $sp^{3}/sp^{2}$ fraction is obtained when the films are deposited at a pressure of $3{\times}10^4$ Torr and a bias voltage of - 50 V. The variation of the structural properties due to thermal stress up to 500$^{\circ}C$ is also examined.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.532-535
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• 2000

We have fabricated a sensor system for on-line monitoring the oxygen permeability and diffusivity of six different polymer films using the miniaturized 6 cathode(Ag)-single anode(Ag/AgCl) type hexagonal oxygen electrode. This system consists of multiple input front-end electronics, signal conditioning circuit using the embedded microcontroller 80C196KC, PC interface circuit and PC with the OS for microcontroller and the operating program for this system. The digital low-[ass filter was programmed and the simulated filter characteristics were enough to eliminate the noise from sensor signal. According to the experimental results, the linearity coefficients of the output voltage to oxygen partial pressure for each sensor electrode of six cathode type oxygen sensor are 0.998, 0.997, 0.998, 0.997, 0.997, 0.997 respectively, and the response times are all within 4 minutes.

• Journal of Mechanical Science and Technology
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• v.19 no.4
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• pp.1018-1026
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• 2005

The proton exchange membrane (PEM) fuel cell system consisting of stack and balance of plant (BOP) was modeled in a MATLAB/Simulink environment. High-pressure operating (compressor type) and low-pressure operating (air blower type) fuel cell systems were con­sidered. The effects of two main operating parameters (humidity and the pressure of the supplied gas) on the power distribution characteristics of BOP and the net system efficiency of the two systems mentioned above were compared and discussed. The simulation determines an optimum condition regarding parameters such as the cathode air pressure and the relative humidity for maximum net system efficiency for the operating fuel cell systems. This study contributes to get a basic insight into the fuel cell stack and BOP component sizing. Further research using muli­object variable optimization packages and the approach developed by this study can effectively contribute to an operating strategy for the practical use of fuel cell systems for vehicles.

• Korean Journal of Optics and Photonics
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• v.13 no.6
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• pp.559-563
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• 2002

We measure the 3-dimensional temporal behavior of the light emitted from the discharge cell of a plasma display panel (PDP) by using a scanned point detecting system. The light signal detected by a PM tube is sent to the oscilloscope, and the oscilloscope is connected to a PC with GPIB. From the resultant temporal behaviors, we could analyze the discharge characteristics of the panel with a Ne-Xe (4%) mixing gas at a 400 torr pressure. The top view of the panel shows that discharge moves from the inner edge of the cathode electrode to the outer cathode electrode, forming an arc shape. The side view of the panel shows that the light is detected up to 150 $\mu\textrm{m}$ up the barrier rib. After a trigger pulse is applied, peak intensity is detected at 730 ns and peak intensity position is located at the center of the ITO electrodes.

• Journal of the Korean Ceramic Society
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• v.39 no.4
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• pp.367-376
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• 2002

Electrical conduction in $SrZr_{1-x}Y_xO_{3-\delta}$((x=0.05, 0.10)-metal electrode system was investigated by impedance spectroscopy and two-probe d.c. conductivity measurement. Electrode conductivity in anodic direction varies with $P_W^{1/2}$( and that in cathodic direction with $P_{O2}^{1/4}$ in oxidizing atmosphere. In hydrogen atmosphere, the addition of water vapor increased the electrode conductivity both in anodic and cathodic direction. Increasing dopant concentration from 5 to 10% showed a more than four times increase in anodic conduction as well as bulk conduction of the solid electrolyte. This observation implies that unfilled oxygen vacancy concentration increases rapidly as the dopant content increases in humid atmosphere. The activation energy of cathodic conduction in Pt and Ag electrode was nearly same below $800^{\circ}C$ which means the rate of cathodic reaction is determined by the reaction in the electrolyte surface rather than on the metal electrodes.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2017.10a
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• pp.74-74
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• 2017

Electrorefining is a key step in pyroprocessing. The electrorefining process is generally composed of two recovery steps - the deposit of uranium onto a solid cathode and the recovery of the remaining uranium and TRU elements simultaneously by a liquid cadmium cathode. Uranium deposit recovered from the solid cathode is a dendritic powder. It is necessary to separate the adhered salt from the deposits prior to the consolidation of uranium deposit. The adhered salt is composed of lithium, potassium, uranium, and rare earth chlorides. Distillation process was employed for the cathode processing. One of the operation methods is distillation of the salt at low temperature ($900^{\circ}C$), and then melting of the deposit at high temperature to avoid a backward reaction. For the development of the salt distiller, the distillation behavior of the low vapor pressure chlorides should be studied. Rare earth chlorides in the adhered salt of uranium deposits have relatively low vapor pressures compared to the process salt (LiCl-KCl). In this study, the evaporation rates of the lanthanum and neodymium chlorides were measured for the salt separation from electrorefiner uranium deposits in the temperature range of $825{\sim}910^{\circ}C$. The evaporation rate of both chlorides increased with an increasing templerature. The evaporation rate of lanthanum chloride varied from 0.12 to $1.68g/cm^2/h$. Neodymium chloride was more volatile than lanthanum chloride. The evaporation rate of neodymium chloride varied from 0.20 to $4.55g/cm^2/h$. The evaporation rate of both chlorides are more than $1g/cm^2/h$ at $900^{\circ}C$. Even though the evaporation rates of both chlorides were less than that of the process salt, the contents of the lanthanide chlorides were small in the adhered salt. Therefore it can be concluded that $900^{\circ}C$ is suitable for the operation temperature of the salt distiller.