@article{oai:repo.qst.go.jp:00082257,
 author = {Satoshi, Yamamoto and Yutaro, Itashiki and Daigo, Tsuru and Go, Matsunaga and Manabu, Takechi and Shigetoshi, Nakamura and Takao, Hayashi and Akihiko, Isayama and Satoshi, Yamamoto and Yutaro, Itashiki and Daigo, Tsuru and Go, Matsunaga and Manabu, Takechi and Shigetoshi, Nakamura and Takao, Hayashi and Akihiko, Isayama},
 journal = {Fusion Engineering and Design},
 month = {Mar},
 note = {The stabilizing plate (SP) of JT-60SA has been designed based on an electromagnetic and a structural analysis. The SP plays a role of both a passive stabilizer of magnetohydrodynamics (MHD) instability and a first wall at low field side in combination with a graphite tile. The SP has a double skin structure with 10 mm thickness each in order to have simultaneously high resistivity in the toroidal direction and high strength against plasma disruption as well as a seismic event. A finite element method for the calculation of the electromagnetic force induced by disruption and the structural analysis has been applied. The most serious event which is fast major disruption, is mainly considered. The eddy current reaches up to 100 MA/m2, which induces electromagnetic force <120 MN/m3. The SP has been modified in order to satisfy the allowable membrane, bend and peak stress of SS316 L. Trial manufacture of a part of the SP has been done to investigate the effect of the weld on the deformation of the SP resulting from the contraction of the weld metal. The arrangement of heat sinks and coolant pipes, and graphite tiles has also been done, taking into account the long pulse operation of the JT-60SA plasma.   1. Introduction The project of JT-60SA [1] is in progress at Naka, Japan, as a satellite tokamak in the  Broader Approach activity under the international collaboration between Japan and Europa. The JT-60SA tokamak, which is the largest superconducting device, was successfully completed in March 2020 and is in the commissioning phase, which is planned by May 2021, including the first plasma initiation. The purpose of JT-60SA is a demonstration and study of the steady-state plasma with high beta targeting on the supplement to ITER toward DEMO and contributing to optimizing ITER operation scenarios. After the commissioning phase, we will upgrade the JT-60SA tokamak for 26 months. We will install many in-vessel components such as in-vessel coils, lower divertor, a cooling system including a heat-sink for in-vessel walls, the stabilizing plate (SP), and additional heating systems. The SP plays a role of both a passive stabilizer of magnetohydrodynamics (MHD) instabilities such as vertical displacement event (VDE) and resistive wall mode (RWM), and the first wall at low field side in combination with a heat-sink as well as a graphite tile. The in-vessel metal wall whose purpose is the stabilization of MHD instabilities is installed in some tokamaks such as NSTX [2], KSTAR [3], EAST [4]. The principle of stabilization of MHD instabilities by the in-vessel metal wall is that eddy current induced by  MHD instabilities produces a magnetic field that pushes plasma back and stabilizes MHD instabilities. The in-vessel metal wall named passive stabilizer plate surrounds the upper and lower region of the plasma at a low field side in tokamaks except for JT-60SA. The in-vessel metal wall called stabilizing plate in JT-60SA surrounds the whole region of plasma at the low field side to obtain the steady-state high beta plasma. Fig. 1 shows the bird’s eye view of the SP as well as a part of the vacuum vessel (VV), error field correction coil (EFCC), fast positioning control coil (FPCC), and resistive wall mode coil (RWMC) of JT-60SA. The SP can be toroidally separated into 18 sections and connected to the vacuum vessel by 74 pedestals which are equipped with 18 support frames. Fig. 2 shows the poloidal cross-section of the SP, the VV, lower and upper divertors in combination with the flux surface of the double- null divertor configuration of the JT-60SA plasma. The plasma does not attach but gets closer to the SP within a distance of 10 mm for effective MHD stabilization. The specification of the SP is listed in the Table 1. The material of the SP is stainless steel 316 L with low cobalt content (Co <0.05 wt%) to avoid the production of  cobalt-60 which is a radioactive isotope and can be produced by the fission reaction with neutrons during deuterium-deuterium experiments. Fig. 3 shows the exploded view of one toroidal section of the SP. The SP consists of the main part of the SP as shown in Fig. 3a) and the support frame having * Corresponding author. E-mail address: yamamoto.satoshi2@qst.go.jp (S. Yamamoto).  Contents lists available at ScienceDirect Fusion Engineering and Design journal homepage: www.elsevier.com/locate/fusengdes https://doi.org/10.1016/j.fusengdes.2021.112361 Received 30 November 2020; Received in revised form 1 February 2021; Accepted 15 February 2021},
 title = {Design of stabilizing plate of JT-60SA},
 volume = {168},
 year = {2021}
}