(FT/P5-32) Ferritic Insertion for Reduction of Toroidal Magnetic Field Ripple on JT-60U

K. Shinohara1), S. Sakurai1), M. Ishikawa1), K. Tsuzuki2), Y. Suzuki1), K. Masaki1), O. Naito1), K. Kurihara1), T. Suzuki1), Y. Koide1), T. Fujita1), Y. Miura1), JT-60 Team1)
1) Japan Atomic Energy Agency, Naka, Ibaraki-ken 311-0193, Japan
2) The Institute of Applied Energy, 1-14-2 Nishi-shimbashi, Minato-ku, Tokyo 105-0003, Japan

Abstract.  Ferritic steel plates have been installed to improve the energetic ion confinement through reducing a toroidal magnetic field ripple. Aiming at cost-effective installation, orbit following calculations of energetic ions were performed for a design of ferritic installation on JT-60U by using the Fully three Dimensional magnetic field Orbit-Following Monte-Carlo (F3D OFMC) code, which was developed for ferritic insert experiments on JFT-2M and can treat complex magnetic field structure produced by ferritic inserts. The installed ferritic steel adds the non-linear magnetic field on magnetic sensors for a plasma control and an equilibrium calculation. We have successfully carried out a real-time plasma control which takes the magnetic field by ferritic steel into account for the first time. The heat load measurement indicates the improved confinement of energetic ions. These results are important for practical application of ferritic steel which is a leading candidate of a structural material on a demo reactor.

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