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Garching bei München, Germany

Matsukawa M.,Japan Atomic Energy Agency | Shimada K.,Japan Atomic Energy Agency | Yamauchi K.,Japan Atomic Energy Agency | Gaio E.,Consorzio RFX | And 2 more authors.
Plasma Science and Technology | Year: 2013

This paper describes a conceptual design study for the circuit configuration of the Error Field Correction Coil (EFCC) power supply (PS) to maximize the expected performance with reasonable cost in JT-60SA. The EFCC consists of eighteen sector coils installed inside the vacuum vessel, six in the toroidal direction and three in the poloidal direction, each one rated for 30 kA-turn. As a result, star point connection is proposed for each group of six EFCC coils installed cyclically in the toroidal direction for decoupling with poloidal field coils. In addition, a six phase inverter which is capable of controlling each phase current was chosen as PS topology to ensure higher flexibility of operation with reasonable cost. Source


Tobita K.,Japan Atomic Energy Agency | Federici G.,Fusion for Energy | Okano K.,International Fusion Energy Research Center
Fusion Engineering and Design | Year: 2014

The main objective of DEMO design activity under the Broader Approach is to develop pre-conceptual design of DEMO options by addressing key design issues on physics, technology and system engineering. This paper describes the latest results of the design activity, including DEMO parameter study, divertor and remote maintenance. DEMO parameter study has recently started with "pulsed" DEMO having a major radius (Rp) of 9 m, and "steady state" DEMO of Rp = 8.2 m or more. Divertor design study has focused on a computer simulation of fully detached plasma under DEMO divertor conditions and the assessment of advanced divertor configuration such as super-X. Comparative study of various maintenance schemes for DEMO and narrowing down the schemes is in progress. © 2014 Elsevier B.V. Source


Syed M.B.,ITER Organization | Patisson L.,ITER Organization | Curtido M.,Fusion for Energy | Slee B.,Fusion for Energy
Nuclear Engineering and Design | Year: 2014

ITER is being designed and constructed with a high level of safety as an essential requirement. In order to meet the safety and performance objectives of ITER and the French regulatory requirements, the Tokamak Complex has been isolated from the potential seismic hazard by anti-seismic bearings. The dynamic characteristics of the anti-seismic bearings were chosen so that the Tokamak Complex will have a fundamental horizontal frequency of 0.55 Hz. The design, manufacturing and qualification of ASBs have been carried out by NUVIA Travaux Speciaux with specific ITER requirements that are much more stringent than the applicable European and French Norms and directives. © 2013 Elsevier B.V. Source


Meunier L.,French Atomic Energy Commission | Barabaschi P.,Fusion for Energy | Tomarchio V.,Fusion for Energy
Fusion Engineering and Design | Year: 2011

JT-60SA is a fusion experiment designed to contribute to the early realization of fusion energy, by providing support to the operation of ITER, by addressing key physics issues for ITER and DEMO and by investigating how to optimize the operation of the next fusion power plants. It is a combined project of Japan and Europe Satellite Tokamak Program, as part of the Broader Approach Agreement and it is to be built in Naka, using the infrastructure of JT-60U. This article describes the finite element analysis performed to assess the mechanical behavior of the TF Coils under the seismic load of the Naka site. One particular type of boundary conditions has been evaluated: the TF Coils are not energized, and all components are at room temperature. This represents the most demanding conditions for the magnet system, as the wedge structure does not add any stiffness and strength due to the lack of centripetal forces on the individual coils; moreover the elastic limit of materials are lower than in cryogenic conditions. The results show that both stresses and displacements are acceptable for the TF Coil system, and that sufficient margin is available. In addition, loads on some of the major components can be extracted: maximum forces in the TF Coils supports, and force distribution on the cryostat base of JT-60SA. © 2011 EURATOM CEA IRFM. Published by Elsevier B.V. All rights reserved. Source


Ferro A.,Consorzio RFX | Gaio E.,Consorzio RFX | Takechi M.,Japan Atomic Energy Agency | Matsukawa M.,Japan Atomic Energy Agency | Novello L.,Fusion for Energy
Fusion Engineering and Design | Year: 2013

The JT-60SA satellite tokamak will be built in Naka, Japan. One of the main aims of this machine is to achieve steady-state high-beta plasmas. To reach this result, passive stabilizing plate (SP) and resistive wall modes (RWM) active control system based on 18 in-vessel coils will be installed. In the present design, these coils are placed on the plasma side of the SP, behind the first wall. This solution maximizes the efficiency in producing fast magnetic fields into the plasma by minimizing the shielding effect of the passive structures. Then, if the power supply (PS) and the control system have sufficient dynamic performance, it is possible to control the RWM with very low magnetic fields. This allows minimizing the Ampere-turns and the power requested to control the RWM. Conversely, the very fast dynamics required represents one of the main issues for the design of the RWM control system. This paper, after having recalled the main specification data for the RWM control system deriving from the physics studies, describes the analyses performed to complete the set of requirements necessary for the PS design. The characterization of coils and feeders is shown and the voltage necessary to produce the required current and bandwidth is quantified. Possible connections among PS and coils are analyzed in order to achieve the highest possible flexibility in controlling the RWM with a reduced set of independent PS. Finally, considerations on reasonable voltage margins to cope with load uncertainties are given. © 2013 Consorzio RFX Associazione Euratom ENEA sulla Fusione. Source

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