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Uto, Hiroyasu; Takase, Haruhiko; Sakamoto, Yoshiteru; Tobita, Kenji; Mori, Kazuo; Kudo, Tatsuya; Someya, Yoji; Asakura, Nobuyuki; Hoshino, Kazuo; Nakamura, Makoto; et al.
Fusion Engineering and Design, 103, p.93 - 97, 2016/02
Times Cited Count：8 Percentile：60.26(Nuclear Science & Technology)Conceptual design of in-vessel component including conducting shell has been investigated in Broader Approach (BA) DEMO design activities, in order to propose feasible DEMO reactor from plasma vertical stability and engineering viewpoint. The conducting shell for the plasma vertical stability will be incorporated behind blanket module, while the location must be close to the plasma surface as possible for the plasma stabilization. We evaluated dependence of the plasma vertical stability on the conducing shell parameters by using a 3-dimensional eddy current analysis code (EDDYCAL). The calculation results showed that the conducting shell requires more than 0.01 m thickness of Cu-alloy on DEMO. On the other hand, the electromagnetic force at the plasma disruption is a few times larger than no conducting shell case because of larger eddy current on conducting shell. The engineering design issues of in-vessel components for plasma vertical stability are presented.
Shiraki, Fumiya*; Yoshikawa, Taeko*; Oshima, Akihiro*; Oshima, Yuji*; Takasawa, Yuya*; Fukutake, Naoyuki*; Oyama, Tomoko*; Urakawa, Tatsuya*; Fujita, Hajime*; Takahashi, Tomohiro*; et al.
Nuclear Instruments and Methods in Physics Research B, 269(15), p.1777 - 1781, 2011/08
Times Cited Count：8 Percentile：53.37(Instruments & Instrumentation)The graded energy deposition of heavy ion beam irradiation to polymeric materials was utilized to synthesize a novel proton exchange membrane (PEM) with the graded density of sulfonic acid groups toward the thickness direction. Stacked Poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) films were irradiated by Xe
ion beam with the energy of 6 MeV/u under a vacuum condition. Irradiated films were grafted with styrene monomer and then sulfonated. The membrane electrode assembly (MEA) fabricated by the function graded PEM showed improved fuel cell performance in terms of voltage stability. It was expected that the function-graded PEM could control the graded concentration of sulfonic acid groups in PEM.
Yoshikawa, Hiroshi; Sakaki, Hironao; Sako, Hiroyuki; Takahashi, Hiroki; Shen, G.; Kato, Yuko; Ito, Yuichi; Ikeda, Hiroshi*; Ishiyama, Tatsuya*; Tsuchiya, Hitoshi*; et al.
Proceedings of International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS '07) (CD-ROM), p.62 - 64, 2007/10
J-PARC is a large scale facility of the proton accelerators for the multi-purpose of scientific researches in Japan. This facility consists of three accelerators and three experimental stations. Now, J-PARC is under construction, and LINAC is operated for one year, 3GeV synchrotron has just started the commissioning in this October the 1st. The completion of this facility will be next summer. The control system of accelerators established fundamental performance for the initial commissioning. The most important requirement to the control system of this facility is to minimize the activation of accelerator devices. In this paper, we show that the performances of each layer of this control system have been achieved in the initial stage.
Takase, Haruhiko; Tobita, Kenji; Sakamoto, Yoshiteru; Uto, Hiroyasu; Mori, Kazuo; Kudo, Tatsuya
no journal, ,
Analysis of plasma position control is one of important issues for design of DEMO reactor on Broader Approach (BA). Especially, plasma performance, blanket design and maintenance scheme influence the plasma position control mutually. Therefore, we made a numerical simulation code that consists of plasma equilibrium analysis, eddy current analysis and plasma motion analysis. Since we analyzed several cases of design using this numerical simulation code, the results will be shown.
Takase, Haruhiko; Uto, Hiroyasu; Sakamoto, Yoshiteru; Mori, Kazuo; Kudo, Tatsuya; Tobita, Kenji
no journal, ,
Pre-conceptual design of DEMO reactor has been preceded under collaboration Japan and Europe (Broader Approach activities (BA)). In the case of DEMO reactor, it is important for design of plasma position control to take into account the actual shape of vacuum vessel and in-vessel components precisely since the design condition of DEMO reactor is different from current tokamak devices and ITER (for example, installation of maintenance ports). To consider the DEMO design condition, the numerical simulation that consists of three modules has been developed. As results, (1) The time constants of eddy current in the breeding blankets are less than 10ms and there is no influence to passive stabilization effect. (2) The stabilization effect of conducting components decreases by considering installation of vertical maintenance port. The adoption of vertical port is related to the choice of the maintenance scenario.
Uto, Hiroyasu; Takase, Haruhiko; Sakamoto, Yoshiteru; Tobita, Kenji; Hiwatari, Ryoji; Mori, Kazuo; Kudo, Tatsuya; Someya, Yoji; Asakura, Nobuyuki
no journal, ,
This presentation describes conceptual design of in-vessel component including conducting shell in DEMO design activities, in order to propose feasible DEMO reactor from plasma vertical stability and engineering viewpoint. The conducting shell design for plasma vertical stability was clarified from the plasma vertical stability analysis, and a conceptual design divided in the toroidal direction for the blanket remote maintenance was proposed. We evaluated dependence of the plasma vertical stability on the conducing shell parameters and electromagnetic force at plasma disruption by using a numerical simulation code (EDDYCAL) with actual shape and position of the vacuum vessel and in-vessel components. The calculation results showed that the double-loop shell has the most effect on plasma vertical stability. On the other hand, while the electromagnetic force at the plasma disruption is a few times larger than no conducting shell case because of larger eddy current on conducting shell.
Takase, Haruhiko; Uto, Hiroyasu; Sakamoto, Yoshiteru; Mori, Kazuo; Kudo, Tatsuya; Hiwatari, Ryoji; Tobita, Kenji
no journal, ,
Plasma position control for DEMO reactor has been studied using numerical simulation, which consists of plasma equilibrium, eddy current and active feedback control analyses. The stabilization effect of in-vessel components, the influence on the magnetic detector and the power of active feedback control coils are evaluated. Especially, the influence on plasma position control by installation of the breeding blanket modules is shown in this paper.
