[en] A new valveless micropump for bi-directional application has been developed and tested. The micropump was fabricated on silicon and glass substrates by micromachining process. The micropump in this study consists of a membrane actuator, a pumping chamber, fluidic channels and two piezoelectric ceramic films. The channels and pumping chamber were etched on a glass wafer and the membrane was made on a silion wafer which is actuated by a piezoelectric ceramic (PZT) film. The geometry of the micropump was optimized by numerical analysis and the performance of the micropump was investigated by the experiments. The maximum flow rate was 323 μL/min and the maximum back pressure was 294 Pa when the membrane actuator of 10 x 10 mm² was driven at 130 Hz and 385 V

[en] The high power RF transmission components are developed for transmitting MW level of RF power continuously in ICRF heating and current drive system. As an important development of RF components, we have improved a Teflon insulator of the 9-3/16' coaxial line connected between the antenna and matching components where VSWR is fairly high depending on antenna-plasma coupling. The electric field strength at a point of contact section between point inner conductor and insulator is calculated using the commercial FEM code (Quick Field). We have improved the shape of the Teflon insulator so as to minimize the electric field strength on insulator. A liquid phase shifter is fabricated to replace a conventional phase shifter. The liquid phase shifter uses the difference between RF wave length in liquid and in gas due to the different relative dielectric constant. RF tests show that stable operation is possible with the peak voltage over 48.75 kV for 300 seconds, and they are reliable RF components for long pulse, high power transmission

[en] Bi₂Sr₂Ca₁Cu₂O_x(BSCCO 2212) superconductor tubes for high efficient current lead application were prepared by centrifugal melting process (CMP). BSCCO 2212 powder was melted at 1200 .deg. C in a resistance furnace using a Pt crucible and poured in a rotating cylindrical mold preheated at 550 .deg. C for 2 hour. The BSCCO tubes with 30 φx150 hx4 t (mm) dimension were successfully fabricated. The solidified BSCCO-2212 samples were heat-treated by partial melting process in oxygen atmosphere. The phase identification and microstructure were investigated by XRD and SEM, respectively. The current-voltage curves at 77 K of the samples were obtained by transport measurement using liquid N₂. The J_c values at 77 K of the tubes partially melted at 840 .deg. C, 860 .deg. C and 880 .deg. C were 492, 430 and 398 A/cm² (1,722, 1,505, 1,393 A/cm² at 65 K), respectively. It was observed that the plate-like grains in BSCCO 2212 tube was more developed in the sample heat-treated at 840 .deg. C. It was found that the critical current of the BSCCO 2212 samples was dependent on the partial melting schedule regarding the grain shape and size of the BSCCO 2212

[en] The antenna of the KSTAR ICRF heating system consists of four current straps, each of which is grounded at the center, and has two coaxial ports, one at each end. The top and bottom ports of each strap are fed by one transmitter. The two ports are connected at tee connector to form a resonant loop, and the coaxial feed line from the transmitter is connected to the tee. One resonant loop with the proto-type antenna is built at the RF test stand in KAERI. It is composed with one current strap, one tee connector and two arms connecting them. Each arm consists of a 6-inch vacuum transmission line, a vacuum feed through, a part of pressurized 9-inch coaxial line, and an adjustable phase shifter to cover wide frequency range of 25-60 MHz. Total electrical length is changeable from 45 to 51 m. Many voltage probes and directional couplers are installed to measure RF voltage of the standing wave, power flow and phase difference. Resonant and matching conditions are investigated for various frequencies

[en] Instrumentation and Control(I and C) of the neutral beam injection(NBI) system for the K-STAR national fusion research project has been working from the start of the project to answer diverse requests arising from various facets of the development and construction phases of the project. In a parallel effort with the software oriented I and C development, there has been existing an enormous amount of hard-wiring I and C works for the NBI facility to be developed and fabricated in schedule. Circuits and hardwired functions have been designed, tested, fabricated, and finally installed to the relevant parts of the system. Some examples of those hard-wired I and C works are related to the vacuum system, gas feeding system, arc detector circuit, ion source monitoring, bending magnet and calorimeter. They are one of those integral parts for the proper operation of the NBI system. Examples of those hard-wired I and C works are introduced in this presentation

[en] Korea (KO) has developed and participated in the Test Blanket Module (TBM) program in the ITER, in which Ferritic martensitic (FM) steel was used as the structural material for the TBM first wall (FW). To develop the fabrication method for the TBM FW and verify its integrity, a half scale sub module mock up was fabricated and integrity test has been prepared. Two manifolds for connecting with the water supplying system in high heat flux (HHF) test were fabricated and welded with the mock up. Pressure and He leak tests were successfully performed without any leak and failure. The flow rates in each channel were measured with the conventional ultrasonic sensor but it shows non uniform flow distribution at each channel differently from the estimation by ANSYS CFX. HHF test conditions were evaluated through the ANSYS CFX analysis considering the above measured flow rates in each channel and it shows non uniform temperature distribution of the FW surface. Now a new manifold design or modification of the fabricated one is being considered for a uniform flow distribution at each channel of the mock up

[en] In 2009 KSTAR experiment campaign, optimization of ICWC(ICRF assisted discharge Wall Cleaning) is carried out to secure reproducibility and reliability of tokamak start-up. ICRF system is modified first before experiment campaign. As operation toroidal magnetic field strength is increased from 1.5T to 3T, the length of resonance loop and power transmission is modified and the driving frequency is increased to 44.2MHz. At the changed operation frequency, RF transmitter is tested and as a result, 647kW RF power is identified at VSWR of 1.37. The density of RF glow plasma for ICWC is relatively lower than that of tokamak plasma so that the vacuum tuning can be used for ICWC glow plasma as well. However, the VSWR is reduced enough for the reliable RF transmitter operation by pule-bypulse tuning. ICWC is carried out with modified ICRF system. In this study, a series of effort is tried to find optimal condition which enables to remove effectively the D2 gas embedded in the tokamak wall. With He/H2 working gas, the effect of the gas mixing rate and pulse duty ratio on ICWC are investigated. And the ICWC efficiency is evaluated with the increased quantity of HD molecule measured by RGA. All 7 sets of experiments are performed. As a result, It is identified that deuterium can be removed effectively due to the increase of reaction rate by the increased hydrogen molecule. It is also confirmed that the HD can be removed more by the increased reaction time between the hydrogen ion and deuterium adsorbed in the tokamak wall

[en] The Korea (KO) has developed liquid a breeder blanket and participated in the Test Blanket Module (TBM) program within the International Thermonuclear Experimental Reactor (ITER) with a Helium Cooled Molten Lithium (HCML) concept. Ferritic Martensitic Steel material is used as structural material for the TBM first wall (FW). In order to develop the fabrication method for the TBM FW, the various manufacturing and joining methods have been developed. In this study, three mock-ups were fabricated to verify the manufacturing of a 1/6-scale mock-up of the TBM FW and preliminary analyses were performed to design a manifold of a 1/6-scale mock-up for uniform flow in the channels. Using Ferritic Martensite Steel material, three kinds of small mock-ups were fabricated such as a cooling channel shape of straight, two cooling channels shape of straight, and a cooling channel shape of U-type. The small mock-ups were manufactured by wire cutting and machining for components of the mock-ups and a welding and HIP, at 1050 .deg. C and 100 MPa for two hours, were performed for bonding. The fabricated small mock-ups were performed pressure tests between the joints to evaluate bonding of the mock-ups

[en] Vacuum system of the neutral beam test stand (NB-TS) at KAERI has been enhanced of its performance by the expansion of the liquid nitrogen(LN2) supply system for the cryosorption pumps from a mere 150L supply reservoir to 5000L field tank installed outside the facility building. The accompanying control system was fabricated and installed to comply with the control needs of the expanded LN2 supply system. The newer LN2 supply system with temperature and level control functions now works satisfactorily for the operation of the cryosorption pumps of the NB beam line

[en] The ICRF system for the KSTAR tokamak is being developed to support long-pulse, high-β, advanced tokamak fusion physics experiments. The ICRF system will deliver 12 MW of rf power to the plasma for 300 seconds through two antennas located in adjacent ports. With the frequency range of 25 to 60 MHz, it provides heating for the plasmas, centrally peaked current drive, and off-axis current drive using mode-conversion for various operating scenarios over a range of magnetic fields. Steady-state relevant ICRF components have been developed in the area of the antenna, the vacuum feedthrough and the matching devices. In this work, rf test results with intermediate power at the frequency of ∼30 MHz are presented