• Journal of the Optical Society of Korea
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• v.13 no.1
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• pp.15-21
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• 2009

High-order harmonic generation from a solid surface affected by the contrast of a laser pulse was studied using an oscillating mirror model. High-order harmonics generated from solid surfaces have unusual properties such as spectral redshift, and an intensity difference between even- and odd-order harmonics which is not reported for high-order harmonics generated by a gas medium. We confirmed that high-order harmonics from solid surfaces have selectivity of polarization as well as cut-off extension and the enhancement of conversion efficiency proportional to laser intensity. And the principle of operation and the characteristics of a plasma mirror system developed for achieving high contrast laser pulses to pursue the experimental realization of high-harmonic generation from solid surfaces are reported. Energy fluence on the plasma mirrors is tunable between $10\;J/cm^2$ and $1000\;J/cm^2$ and around 1000 shots are available before the plasma mirrors require replacement.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.70-77
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• 2024

A low energy ion irradiation system based on the deuterium arc ion source with a high perveance of 1 µP for a single extraction aperture has been successfully developed for the investigation of ion irradiation on plasma-facing components including the first mirror of plasma optical diagnostics system. Under the optimum operating condition for mirror testing, the ion source has a beam energy of 200 eV and a current density of 3.7 mA/cm². The ion source comprises a magnetic cusp-type plasma source, an extraction system, a target system with a Faraday cup, and a power supply control system to ensure stable long time operation. Operation parameters of plasma source such as pressure, filament current, and arc power with D₂ discharge gas were optimized for beam extraction by measuring plasma parameters with a Langmuir probe. The diode electrode extraction system was designed by IGUN simulation to optimize for 1 µP perveance. It was successfully demonstrated that the ion beam current of ~4 mA can be extracted through the 10 mm aperture from the developed ion source. The target system with the Faraday cup is also developed to measure the beam current. With the assistance of the power control system, ion beams are extracted while maintaining a consistent arc power for more than 10 min of continuous operation.

• Journal of Marine Life Science
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• v.8 no.2
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• pp.150-159
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• 2023

To determine the toxic effects of the mirror carp, Cyprinus carpio nudus on waterborne nitric acid exposure, they were exposed to waterborne nitric acid at 0, 4, 20, 100, 500, and 2,500 mg NO₃^-/L for 96 h. The semi-lethal concentration (LC₅₀) of the scented fish by 96 hours of acute exposure to nitric acid was 1,433.54 mg NO₃^-/L. The physiological changes of waterborne nitric acid exposure on mirror carp were evaluated through hematologic properties, and RBC count showed a significantly decreased (p < 0.05). The change in the ion control ability of the mirror carp according to exposure to waterborne nitric acid was evaluated through the plasma inorganic component, and calcium and magnesium were significantly decreased (p < 0.05) in the plasma inorganic component. The health and stress status of the mirror carp due to exposure to waterborne nitric acid were evaluated through plasma organic ingredients, and the plasma organic component glucose showed a significantly increase (p < 0.05). Changes in liver damage and enzyme activity due to waterborne nitric acid exposure were evaluated through plasma enzyme components, the enzymatic activities of plasma AST, ALT, and ALP were significantly decreased (p < 0.05) in high levels of waterborne nitric acid exposure. The results of the present study suggest that waterborne nitric acid exposure to C. carpio nudus can toxicly affect survival, hematologic properties, and plasma components.

• Journal of the Optical Society of Korea
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• v.16 no.1
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• pp.80-84
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• 2012

A high reflectance mirror, which has very low absorption and scattering loss, was coated onto a crystalline substrate by ion beam sputtering and then annealed at $450^{\circ}C$. We carefully selected the mirror coating material, and designed the high reflectance mirror, in order to avoid UV degradation which comes from the He-Ne plasma. We measured the surface roughness of the Zerodur substrate using phase shift interferometry and atomic force microscopy, and compared it with the TIS scattering of the mirror. The cavity ring-down method was used to measure the absorption of the mirror, and the thin film structure was correlated to its results. We also compared the optical properties of coated mirrors before and after annealing.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.10
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• pp.98-106
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• 1996

A thin film of aluminum for ultra large scale integrated circuits metalization has been deposited on TiN and SiO$_{2}$ substrates by plasma assisted chemical vapor deposition using DMEAA (dimenthylethylamine alane) as a precursor. The effects of plasma on surface topology and growth characteristics were investigated. Thermal CVD Al could not be got continuous films on insulating subsrate such as SiO$_{2}$. However, it was found that Al films could be deposited on SiO$_{2}$ substate without any pretreatments by the hydrogen plasma for pyrolysis of DMEAA. Compared to the thermal CVD, PACVD films showed much better reflectance and resistance on TiN and SiO$_{2}$ substrate. We obtained mirror-like PACVD Al film of 90% reflectance and resistance on TiN and SiO$_{2}$ substrates. We obtained mirror-like PACVD Al film of 90% reflectance on TiN substrate. Excellent conformal step coverage was obtained on submicron contact holes ;by the PACVD blanket deposition.

• Journal of fish pathology
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• v.35 no.1
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• pp.65-75
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• 2022

Mirror carp, Cyprinus carpio nudus (weight 26.2±3.1 g, length 11.8±0.5 cm) were exposed to waterborne total ammonia nitrogen (TAN) at 0, 2, 4, 8, 16, 32, 64 and 128 mg TAN/L. The lethal concentration 50 (LC₅₀) of mirror carp, C. carpio nudus exposed to waterborne ammonia was 60.38 mg TAN/L. The red blood cell (RBC) count was significantly reduced by ammonia exposure, whereas there was no significant changes in the hemoglobin concentration and hematocrit value. In the plasma components, glucose, total protein, aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were significantly increased by ammonia exposure. The results of this study suggest that the ammonia exposure to C. carpio nudus affects the survival rates, hematological parameters and plasma components as toxicity.

• Journal of the Korean Vacuum Society
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• v.10 no.1
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• pp.98-103
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• 2001

A new application of dirchroic mirror for the improvement of luminance and luminous efficacy in an AC-Plasma Display Panel (PDP) is suggested. Only about half of the Vacuum Ultraviolet (VUV) generated in the reflective PDP cell is used for the excitation of the phosphor. We are suggesting an idea of adopting a dichroic mirror which can reflect the VUV toward the phosphor which otherwise is absorbed by the front panel. The optical constants of the thin films of dirhroic mirror were determined from the photometric measurements through an iteration process of matching calculated and measured values of the reflectance and transmittance in the VUV wavelength region. From these results, we could design such a filter whose high reflection zone is centered at 147nm by a computer simulation accurately. The 147nm VUV is radiated from Xenon 3Pl state which is dominantly used to activate the phosphor in the PDP cell. The dichroic mirror was made with an electronbeam evaporator and its reflectance was measured by a reflectometer. We confirmed the usefulness of the dichroic mirror for the improvement of efficiency with experiments done by test panels. The panel with mirror shows improved luminance and luminous efficacy by 20∼30％.

• JSTS:Journal of Semiconductor Technology and Science
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• v.1 no.2
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• pp.132-139
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• 2001

We considered the uniformity of fabricated micromirror arrays by characterizing the fabrication process and calculating the appropriate driving voltages of micromirrors used as virtual photomask in maskless photolithography. The uniformity of the micromirror array in terms of driving voltage and optical characteristics is adversely affected by factors, such as the air gap between the bottom electrode and the mirror plate, the spring shape and the deformation of the mirror plate or torsion spring. The thickness deviation of the photoresist sacrificial layer, the misalignment between mirror plate and bottom electrode, the aluminum deposition condition used to produce the spring and the mirror plate, and initial mirror deflection were identified as key factors. Their importance lies in the fact that they are related to air gap deviations under the mirror plate, asymmetric driving voltages in left and right mirror directions, and the deformation of the Al sring or mirror plate after removal of the sacrificial layer. The plasma ashing conditions used for removing the sacrificial layer also contributed to the deformation of the mirror plate and spring. Driving voltages were calculated for the pixel operation of the micromirror array, and the non-uniform characteristics of fabricated micromirrors were taken into consideration to improve driving performance reliability.

• Nuclear Engineering and Technology
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• v.56 no.2
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• pp.451-462
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• 2024

In order to optimize the operational safety and reliability of the upper launcher for the CFETR ECRH system, a design of the launcher based on the remote steering concept is currently being carried out for comparison with the front steering equivalent. This paper presents the remote steering system's conceptual design and simulation analysis. A Square Corrugated Waveguide (SCW) of 65 × 65 mm has been designed with an optimized length of 9.35 m. By changing the relative length of the waveguide, the transmission efficiency of the SCW is optimized within the range of steering angles ±12°. Different error factors are investigated in detail, and corresponding acceptable error ranges are provided. Considering these error factors and ignoring ohmic losses and thermal effects, the relative transmission efficiency of the SCW is estimated to be >98 % within the steering angle range. A matching steering unit for the SCW is designed, which consists of an ellipsoidal focusing mirror and a steerable flat mirror. The detailed design of the steerable mirror motion trajectory is presented. Also, the influence of the possible beam incident errors caused by the steering unit on the transmission efficiency is analyzed in detail.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.954-964
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• 2021

Mirror carp Cyprinus carpio nudus (weight 42.0±3.8 g, length 14.3±0.4 cm) were exposed to different concentrations of waterborne copper (0, 100, 200, 400, 800, and 1,600 ㎍ Cu²⁺·L^-1) at 20.3℃ for 96 h. The lethal concentration 50 of waterborne copper was 1,176.45 ㎍ Cu²⁺·L^-1. Among hematological parameters, red blood cell count was significantly decreased, whereas there were no significant changes in the hemoglobin concentration and hematocrit value. Among the inorganic plasma components, calcium was significantly decreased following copper exposure. Conversely, organic plasma components such as glucose and total protein were significantly increased. Similarly, enzymatic components, such as aspartate transaminase, alanine transaminase, and alkaline phosphatase, were also significantly increased. These findings suggest that the copper exposure is detrimental to the survival rates and physiology of C. carpio nudus.