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Kyung Cheol Choi – 1st expert on this subject based on the ideXlab platform
49.3: Invited Paper: High Efficient Discharge Mode in an AC PDP with an Auxiliary ElectrodeSID Symposium Digest of Technical Papers, 2020Co-Authors: Kyung Cheol Choi, Cheol JangAbstract:
A high efficacy AC PDP with an Auxiliary Electrode was investigated with the aim of attaining a better understanding of the discharge mechanism in a display cell. There are three types of discharge modes in an AC PDP with an Auxiliary Electrode; however, only two discharge modes that can decrease the discharge current are recommended for use in a high efficacy AC PDP. The discharge current decreased as the Auxiliary pulse voltage increased because the wall charges on the sustain Electrode were erased. However, the IR intensity did not decrease as the Auxiliary pulse was applied. It was also found that the Auxiliary pulse provides priming particles for the following periodic sustain pulse discharge. Consequently, there is a decrease in the discharge current without a reduction of the luminance and priming particles due to the Auxiliary pulse. This can enhance the excitation rate of the discharges generated in the display cell of an AC PDP with an Auxiliary Electrode.
Numerical Analysis of Microplasma Generated in the Plasma Display Pixel With an Auxiliary ElectrodeIEEE Transactions on Plasma Science, 2011Co-Authors: Kyung Cheol ChoiAbstract:
We investigated the microplasma that is generated in a plasma display pixel with an Auxiliary Electrode by using numerical simulation. In particular, the effect of the Auxiliary Electrode on the efficacy of the plasma display was analyzed. The voltage of the sustain Electrode was changed from 190 to 230 V, and the voltage of the Auxiliary Electrode was changed from 0 to 40 V. As the voltage of the Auxiliary Electrode increased at a given sustain voltage, the discharge current decreased, and the delay time of the discharge increased. The average density of the charged particles and the Xe excited species showed a tendency identical to that of the discharge current. The vacuum ultraviolet output and the electrical power decreased, and the luminous efficacy increased as the voltage of the Auxiliary Electrode increased. In the case of Xe excitation efficacy, the peak value in the Auxiliary period increased as the voltage of the Auxiliary Electrode increased, whereas the peak value in the sustain period was shown to be comparable to the variance of the voltage of the Auxiliary Electrode. The infrared intensity increased as the voltages of the sustain and Auxiliary Electrodes increased. In order to verify the effect of the Auxiliary Electrode, the time-spatial distributions of the electrons and excited species were also discussed.
P‐92: Analysis of Wall Charge Distribution in an AC PDP with an Auxiliary Electrode Using a Two‐Dimensional Numerical SimulationSID Symposium Digest of Technical Papers, 2010Co-Authors: Kyung Cheol ChoiAbstract:
A two-dimensional simulation code is developed in this study to verify the dynamics of a plasma discharge in an AC PDP with multiple Electrodes. Simulation results showed that a pulse applied to the Auxiliary Electrode contributed to the generation of more excited species as well as increased luminous efficacy. Furthermore, the Xe excitation efficacy and wall charge distribution with and without an Auxiliary Electrode was simulated.
B.y. Tang – 2nd expert on this subject based on the ideXlab platform
plasma immersion ion implantation of the interior surface of a large cylindrical bore using an Auxiliary ElectrodeJournal of Applied Physics, 1998Co-Authors: Xuchu Zeng, T K Kwok, B.y. TangAbstract:
A model utilizing cold, unmagnetized, and collisionless fluid ions as well as Boltzmann electrons is used to comprehensively investigate the sheath expansion into a translationally invariant large bore in the presence of an Auxiliary Electrode during plasma immersion ion implantation (PIII) of a cylindrical bore sample. The governing equation of ion continuity, ion motion, and Poisson’s equation are solved by using a numerical finite difference method for different cylindrical bore radii, Auxiliary Electrode radii, and voltage rise times. The ion density and ion impact energy at the cylindrical inner surface, as well as the ion energy distribution, maximum ion impact energy, and average ion impact energy for the various cases are obtained. Our results show a dramatic improvement in the impact energy when an Auxiliary Electrode is used and the recommended normalized Auxiliary Electrode radius is in the range of 0.1–0.3.
Pulsed sheath dynamics in a small cylindrical bore with an Auxiliary Electrode for plasma immersion ion implantationPhysics of Plasmas, 1997Co-Authors: X.c. Zeng, T K Kwok, B.y. TangAbstract:
The temporal evolution of the plasma sheath in a small cylindrical bore with an Auxiliary Electrode is calculated for zero-rise-time voltage pulses. The ion density, flux, dose, ion energy distribu-tion, and electric field are determined by solving Poisson’s equation and the equations of ion motion and continuity using finite difference methods. Our results indicate that the implantation time is about halved and slightly more than 50% of the ions possess impact energy higher than the maximum achieved when an Auxiliary Electrode is absent. The resulting ion flux, ion current, as well as ion energy distribution, are also determined.
effects of the Auxiliary Electrode radius during plasma immersion ion implantation of a small cylindrical boreApplied Physics Letters, 1997Co-Authors: X.c. Zeng, T K Kwok, B.y. Tang, T E SheridanAbstract:
The temporal evolution of the plasma sheath in a small cylindrical bore in the presence of an Auxiliary Electrode is determined for different Electrode radii. The ion density, velocity, flux, dose, ion energy distribution, and average impact energy are calculated by solving Poisson’s Equation and the equations of ion motion and continuity using finite difference methods. The particle-in-cell method is also used to confirm the validity of the data. Our results indicate that more ions will attain high impact energy when the Auxiliary Electrode radius is increased, but the dose will decrease. Our results suggest that the normalized Auxiliary Electrode radius should range from 0.10 to 0.30 in order to maximize the dose and produce a larger number of ions with higher impact energy.
Jingkun Yu – 3rd expert on this subject based on the ideXlab platform
behavior and mechanism of in situ synthesis of Auxiliary Electrode for electrochemical sulfur sensor by calcium aluminate systemCeramics International, 2020Co-Authors: Jingkun Yu, Lei Yuan, Chen Tian, Yuting ZhouAbstract:
Abstract The behavior and mechanism of in-situ synthesis of the Auxiliary Electrode for sulfur sensor were investigated in this work, aiming for better application of calcium aluminate system in synthesizing the Auxiliary Electrode used for sulfur sensor. The in-situ reaction experiment was developed. In addition, the thermodynamic and kinetic calculations were adopted to further study the in-situ reaction possibility and the reaction rate. The results indicated that the value of lg(a[S]/a[O]) should be greater than a particular value to ensure the occurrence of the in-situ reaction. After immersion into the molten iron, the CaS phase was synthesized in the calcium aluminate system. The relationship between the reaction rate and reaction time was exponential, and the initial reaction rate was affected by the CaO content incorporated in the calcium aluminate system and the sulfur content in the molten iron. The initial in-situ reaction rate greatly increased with the increase of the CaO content and sulfur content. For example, the initial reaction rate was as high as 14.87 s-1 when the calcium aluminate system containing 60 wt% of CaO and for a sulfur content of 0.077 wt% in the molten iron. Moreover, the reason that the sulfur sensor fabricated by the ZrO2(MgO) tube with the calcium aluminate coating with different components had the same response time when measuring the different sulfur contents in the molten iron was further explained.
synthesis of an Auxiliary Electrode by laser cladding coating for in situ electrochemical sulfur sensingMaterials Letters, 2015Co-Authors: Jingkun Yu, Yifan JiangAbstract:
Abstract Compact Auxiliary Electrode layer (MgS+MgO–PSZ) was fabricated on the MgO partially stabilized zirconia (MgO–PSZ) substrates by laser powder cladding (LPC) technique. The microstructure, composition and electrochemical performance of the MgS+MgO–PSZ layer were investigated using X-ray diffraction, scanning electron microscope and electrochemical impedance spectroscopy. The result indicated that the structure of the coating was dense and uniform. Furthermore, the Auxiliary Electrode was found to be efficient for zirconia-based sensor by forming numerous MgS/MgO–PSZ interface that make the S/O equilibrium established effectively.
Corrosion of MgO-PSZ in a HF solution and its effect on synthesis of an Auxiliary Electrode for high-temperature sulfur sensorsMeasurement Science and Technology, 2012Co-Authors: Lin Li, Jingkun YuAbstract:
An Auxiliary Electrode for high-temperature sulfur sensors was synthesized with H2S at the surface of zirconia partially stabilized by magnesia (MgO-PSZ). MgO-PSZ was first corroded in a 40% HF solution under ultrasonic conditions at room temperature for different times. A sulfur sensor, Mo|Mo, Mo2S3|ZrS2 + MgS|ZrO2(MgO)|ZrS2 + MgS|[S]Fe|Mo, was developed and tested in carbon-saturated liquid iron. The results show that a phase transformation from tetragonal to monoclinic takes place on the surface of ZrO2 after MgO-PSZ is exposed to a HF solution. HF treatment of MgO-PSZ can promote formation of the Auxiliary Electrode. The variations of electromotive force versus [wt% S] can be obtained as follows: E = −53.247 ln [wt%S] + 142.86 (r = 0.97).