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Publications (7)0 Total impact

  • Conference Proceeding: Thermal cycling tests of plasma facing components for fusion experimental reactors at JAERI
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    ABSTRACT: Recent results of R&D on plasma facing components for fusion experimental reactors such as the ITER/FER (International Thermonuclear Experimental Reactor/Fusion Experimental Reactor) are presented. Plasma facing components will be exposed to severe heat loads. Thermal cycling tests for first wall mock-ups and divertor mock-ups have been carried out under specified heat flux conditions of ITER/FER in high heat flux test facilities at JAERI. Tests at a stationary heat flux of 0.2 MW/m <sup>2</sup> for first wall mock-ups, exposed in the normal heat flux part, have confirmed their durabilities and reliabilities against the cyclic heat loads. In experiments at a stationary heat flux of 0.6 MW/m <sup>2</sup>, with exposure also in the high heat flux part, only the radiatively cooled first wall mock-up was tested. A ceramic sleeve covered with pure titanium between the armor and the cooling structure was damaged before reaching a stationary heat flux of 0.6 MW/m<sup>2 </sup>. The authors have also confirmed the integrity and the durability of the bonds in the thermal cycling test of brazed carbon-fiber-composite/copper divertor mock-ups at a simulated stationary surface heat flux of 10 MW/m<sup>2</sup> for 1000 cycles
    Fusion Engineering, 1991. Proceedings., 14th IEEE/NPSS Symposium on; 11/1991
  • Conference Proceeding: Operation of JT-60 NBI and NBI system for JT-60 upgrade
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    ABSTRACT: The JT-60 JAERI (Japan Atomic Energy Research Institute) Tokamak-60 neutral beam injector (NBI) has been successfully operated for three years, delivering a neutral beam power of 20 MW at a beam energy of 75 keV. The helium-beam injection into JT-60 was performed to investigate exhaustion of fusion alpha particles from the plasma. The helium-ion beam current extracted from ion sources was 40-45 A at an energy of 31 keV. The injection power was about 0.4 MW. In the helium-beam operation, the helium gas in the beamline chamber was pumped out by a condensed SF<sub>6</sub> gas cryosorption pump. The JT-60 neutral beam injector will be modified to inject a 120-keV deuterium beam into the JT-60 upgrade, which will start to operate at the beginning of 1991
    Fusion Engineering, 1989. Proceedings., IEEE Thirteenth Symposium on; 11/1989
  • Conference Proceeding: Recent activities on negative ion beams at JAERI
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    ABSTRACT: Recent results from the negative-ion source experiments and design works of negative-ion-based NBI (neutral beam injection) systems for the JAERI (Japan Energy Research Institute) tokamak (JT-60U) and the FER (Fusion Experimental Reactor) are presented together with a description of the long-range R&D program. A 50-keV, 7.8-A negative-hydrogen-ion beam has been produced successfully for a duration of 100 ms using a cesium-supplied volume source which has 253 extraction apertures of 11.3 mm in diameter. The maximum ion-beam current density is 30 mA/cm<sup>2 </sup> at the source pressure of 1.3 Pa. On the basis of recent promising results from the negative-ion sources, injection of a 500-keV, 10-MW deuterium beam into the JT-60U plasmas in 1994 to heat the core plasma and to drive the plasma current is proposed
    Fusion Engineering, 1989. Proceedings., IEEE Thirteenth Symposium on; 11/1989
  • Conference Proceeding: High heat flux experiments at JAERI
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    ABSTRACT: Recent R&D results on high-heat flux components are presented, including construction of a new test stand. The test stand can extract an electron beam of 4.1 at 100 keV. E-folding divergence of the beam is 1.7 mrad, and the latest beam performance is also described. At the original test stand, which can produce hydrogen-ion beams of 50 A at 100 keV for 10 s, high- Z divertor armors, were tested. Tungsten plates brazed on copper blocks have been proven to have enough durability against heat flux under 10 MW/m<sup>2</sup>. Carbon-fiber-carbon (CFC) composites were tested at the new electron-beam test stand and an electron-beam welding machine. Under disruption-simulation conditions, evaporation weight loss of CFC was lower than that of isotropic graphite
    Fusion Engineering, 1989. Proceedings., IEEE Thirteenth Symposium on; 11/1989
  • Conference Proceeding: Inverter type high voltage DC power supply for negative-ion-based neutral beam injectors
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    ABSTRACT: A design of a high-voltage DC power supply for future neutral beam injectors (NBI) is presented together with the latest R&D results for a 100-kV, 5-A, 5-kHz inverter-type power supply. A negative-ion based NBI is used for heating and current drive in the JT-60U (JAERI Tokamak-60 upgrade) and the FER (Fusion Experimental Reactor). For a high-voltage DC power supply of 500-1000 kV, an inverter-type DC power supply has been adopted. It consists of low-voltage converters, inverters, step-up transformers, and high-voltage rectifiers. Ion sources are protected from electrical breakdowns by stopping the inverters. As the first step, the same system was used in the 100-kV, 5-A acceleration power supply of the JAERI (Japan Atomic Energy Research Institute) electron-beam irradiation stand. The power supply is based on 5-kHz inverters. After the dummy load test, the power supply operated in conjunction with a plasma electron gun, and a 100-keV, 4-A electron beam has already been extracted
    Fusion Engineering, 1989. Proceedings., IEEE Thirteenth Symposium on; 11/1989
  • Conference Proceeding: The Fusion Experimental Reactor (FER)-design concepts
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    ABSTRACT: The Fusion Experimental Reactor (FER) is a D-T-burning tokamak machine currently being designed. It is expected to provide physical information and technical experiences that will be sufficient to proceed towards the DEMO Fusion Reactor which will demonstrate electric power generation by fusion energy. An efficient ash exhaust, a hybrid current drive operation, the use of a 3% ripple field, the technological achievements in R&D of the magnets, and the negative-ion beam system are expected to allow the FER to achieve its cost-effectiveness
    Fusion Engineering, 1989. Proceedings., IEEE Thirteenth Symposium on; 11/1989
  • Article: Primary research and development needs for fusion experimental reactors: Perspectives
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    ABSTRACT: The time has come for fusion experimental reactor programmes (ITER/FER) to enter the engineering design phase, where the large scale models which are capable of extrapolation to the construction of reactors will be developed as the core of the main activities. A brief review of the present status of the required R&D for experimental reactors, and the technological realization perspectives, are described.
    Fusion Engineering and Design.