[en] A facile solvothermal technique is developed to prepare a nickel oxide precursor which is subsequently calcined in air at 300 °C for 4 h to convert it to NiO nanospheres. These nanospheres are assembled from ultrathin mesoporous nanosheets that possess high surface areas. The final product is characterized by various techniques: thermogravimetric analysis, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron spectroscopy, and nitrogen adsorption–desorption method. Such a highly desired structure with a great surface area of 213 m²/g is believed to be formed through the Ostwald ripening mechanism. Electrochemical measurements show that our electrode can exhibit a high specific capacitance of 803 F g⁻¹ at a discharge current density of 2 A g⁻¹. The electrode also possesses excellent long-term stability in an alkaline electrolyte. These interesting properties promote it to be a potential supercapacitor electrode material

[en] The objective of this report is to present the manufacturing, assembling and testing process of IPS Inner Assembly used in Fuel Test Loop(FTL) pre-operation test. The majority of the manufactured components are test fuels, inner assembly structures and subsidiary tools that is needed during the assembly process. In addition, Mock-up test for the welding and brazing is included at this stage. Lower structure, such as test fuels, fuel carrier legs are assembled and following structures, such as fuel carrier stem in the middle structure, top flange in the top structure are assembled together each other. To Verify the Reactor Coolant Pressure Boundary(RCPB) function in IPS Inner Assembly helium leak test and hydraulic test is performed with its acceptance criteria. According to the ASME III code Authorized Nuclear Inspector(ANI) is required during the hydraulic test. As-built measurement and insulation resistance test are performed to the structures and instrumentations after the test process. All requirements are satisfied and the IPS Inner Assembly was loaded in HANARO IR-1 hole in September 25, 2009

[en] Jaffe's expression has been used to study two-centered nuclei systems in prolate spheroidal co-ordinates. It is a series expansion of the radial distance and is applied to get the wavefunction in negative energies. In this study, Jaff's expression is generalized to the whole range of energy by introducing a complex variable. We found a strongly energy-dependent divergence at negative energies near the threshold limit. As well as the diverging dependence, and oscillating feature was also observed at positive energy. These behaviors are not tolerable, not only for studying highly excited states but also for implementing various applications such as the quantum defect theory whose short-range parameters should be smooth over the whole energy range. We clarify the origin of these problematic behaviors of the generalized Jaffe-s expression by inspecting its expression mathematically. Thereafter, a modified expression is presented and tested to remove all energy dependence on both sides of the energy folds. he new expression is shown to be successful in removing the discontinuity at the threshold energy, and the wavefunction amplitudes near the origin are almost constant and smooth on the energy plane

[en] A high-current electron beam generator has been developed. The energy and the average current of the electron beam are 2 MeV and 50 mA, respectively. The electron beam generator is composed of an electron gun, RF acceleration cavities, a 260-kW RF generator, electron beam optics components, and control system, etc. The electron beam generator will be used for the development of a millimeter-wave free-electron laser and a high average power infrared free-electron laser. The machine will also be used as a user facility in nuclear industry, environment industry, semiconductor industry, chemical industry, etc. (author). 15 tabs., 85 figs

[en] Extraction of dilute metal ions from water was performed near room temperature with a variety of ionic liquids. Distribution coefficients are reported for fourteen metal ions extracted with ionic liquids containing cations 1-octyl-4-methylpyridinium [4MOPYR]⁺, 1-methyl-1-octylpyrrolidinium [MOPYRRO]⁺ or 1-methyl-1-octylpiperidinium [MOPIP]⁺, and anions tetrafluoroborate [BF₄]⁺, trifluoromethyl sulfonate [TfO]⁺ or nonafluorobutyl sulfonate [NfO]⁺. Ionic liquids containing octylpyridinium cations are very good for extracting mercury ions. However, other metal ions were not significantly extracted by any of these ionic liquids. Extractions were also performed with four new task-specific ionic liquids. Such liquids containing a disulfide functional group are efficient and selective for mercury and copper, whereas those containing a nitrile functional group are efficient and selective for silver and palladium

[en] In this report we present a theoretical study of bare optical resonators having in mind to extend it to active resonators. To compute diffractional losses, phase shifts, intensity distributions and phases of radiation fields on mirrors, we coded a package of numerical procedures on bases of a pair of integral equations. Two numerical schemes, a matrix formalism and an iterative method, are programmed for finding numeric solutions to the pair of integral equations. The iterative method had been tried by Fox and Li, but it was not applicable to cases for high Fresnel numbers since the numerical errors involved propagate and accumulate uncontrollably. In this report, we implemented the matrix method to extend the computational limit further. A great deal of case studies are carried out with various configurations of stable and unstable resonators. Our results presented in this report show not only a good agreement with the results previously obtained by Fox and Li, but also a legitimacy of our numerical procedures in high Fresnel numbers

[en] As a result of the cooperative research between the KAERI and Peking University, the key technologies of superconducting acceleration cavity and photoelectron gun have been developed for the application to high power free electron lasers. A 1.5-GHz, 1-cell superconducting RF cavity has been designed and fabricated by using pure Nb sheets. The unloaded Q values of the fabricated superconducting cavity has been measured to be 2x10⁹ at 2.5K, and 8x10⁹ at 1.8K. The maximum acceleration gradient achieved was 12 MeV/m at 2.5K, and 20MV/m at 1.8 K. A cryostat for the 1-cell superconducting cavity has been designed. As a source of electron beam, a DC photocathode electron gun has been designed and fabricated, which is composed of a photocathode evaporation chamber and a 100-keV acceleration chamber. The efficiency of the Cs2Te photocathode is 3% nominally at room temperature, 10% at 290 deg C. The superconducting photoelectron gun system developed has been estimated to be a good source of high-brightness electron beam for high-power free electron lasers

[en] The research reactor pool includes special tools, instrumentations, underwater camera, etc. for reactor operation, isotope production and fuel handling. The existing pool hanger attached to the embedded plate in pool liner has not only restrictions for moving from one location to another and replacement with new one, but also careful attention for deciding the position not to interface with the other structures because it is attached in the embedded plate by welding method. To resolve these limitations, the detachable pool hanger but not permit slipping during seismic event is developed and its characteristics are presented. The movable pool hanger has characteristics of the movability and the detachability. The movability of that helps the work efficiency when that’s position change is required. The detachability means that the movable pool hanger is removable from the pool liner without grinding. Bolt joint type makes the possible the existing pool hanger with new one without grinding which requires time and labor.

[en] The two-photon excitation of 7¹S₀, 7³D₂, 7¹D₂, and 6³D₂ states in mercury was achieved by a pulsed UV dye laser radiation. The time-resolved fluorescence signal provided an accurate determination of the radiative lifetimes and the total quenching rate constant. The measured lifetimes for 7¹S₀, 7³D₂, 7¹D₂, and 6³D₂ states are 32.0±0.5, 19.5±0.5, 36.5±0.3, and 10.1±0.3 ns, respectively. The 7³D₂ (or 7¹D₂) quenching by Ar, He,CCl₄, N₂, and H₂ molecules are large and those are in the 10^-9∼ 10^-10 cm³ molecule ^-1 s^-1 range. The product spectra were obtained with a high-resolution double-grating monochromator. The dominant quenching mechanism is thought to be both an intermultiplet (between singlet and triplet) mixing and a fine structure (between J=2 and J=1, or J=2 and J=3) mixing (12). The 7¹S₀ quenching by Ar was small (<^∼10^-14 cm³ molecule^-1 s^-1), but the rate constant for CCl₄, N₂, and NO are large (^∼10^-10 cm³ molecule ^-1 s^-1). The NO(A-X) spectrum was obtained in the presence of N₂ and Hg(7¹S₀) atoms. HgCl(B) molecules might be formed by the reaction between the Hg(7¹S₀) atoms and CCl₄ molecules. Further clarification is needed. The degree of polarization of the LIF signals was measured. In the absence of the quenching gases, the LIF signals are highly polarized. The depolarization effect for the 7¹D₂ and 7³D₂ was examined in the presence of Ar. The 7¹D₂ state which has the longer lifetime was more depolarized at 3.0 Torr Ar than 7³D₂ state. (author)

[en] As a result of the cooperative research between KAERI and BINP, a FIR FEL having tunable range of output wavelength from 30 μm to 50 μm. The peak power is 10kW at maximum. The micropulse width is 10 ps and the macropulse width is 5 μs. The repetition rate of micropulses is 2.8 GHz and that of macropulses is 1 - 10 Hz. In addition to the FIR FEL system, many key technologies of high power FELs have been developed. Among them are there electron accelerator technology, design and optimization of electron beamline, design of undulator, measurement of magnetic field of undulators, high-voltage technology, optical cavity, etc.. (author). 10 refs., 11 tabs., 48 figs