A mechanical design for ferritic steels to reduce toroidal field ripple in the JFT-2M

Author

Nakayama, T. ; Yamamoto, M. ; Abe, M. ; Shibata, T. ; Otsuka, M. ; Akiyama, T. ; Sato, Kiminori ; Kikuchi, K. ; Wada, Y. ; Koike, T. ; Miura, Y. ; Sato, M. ; Kimura, Hiromitsu

Author_Institution

Power & Ind. Syst. R&D Lab., Hitachi Ltd., Ibaraki, Japan

fYear

1999

fDate

1999

Firstpage

227

Lastpage

230

Abstract

A modification of JFT-2M was done in order to reduce the toroidal magnetic field (TF) ripple, using ferritic boards (FBs) between the TF coil and vacuum vessel. The arrangements (thickness in minor radius direction, toroidal position and toroidal width) of the FBs are determined so as to minimize the ripple at each TF coil under the restriction of existing ports, diagnostics, and heating systems. The FBs are supported from TF coil cases. The support structures are designed taking into account all coil current patterns of the JFT-2M. The number of the boards can be changed depending on the TF strength. Results of an electromagnetic force test after installation show no deformation of the support structure. The computations about FBs show a reduction of the fundamental mode ripple from 2.1% to 0.8% at (R,Z)=(1.6 m,0.0 m) for a TF strength B_t=2.2 T

Keywords

Tokamak devices; electromagnets; fusion reactor design; magnetic fields; JFT-2M; electromagnetic force; ferritic boards; ferritic steel; fundamental mode ripple; mechanical design; support structures; toroidal field ripple; Coils; Degradation; Electromagnetic forces; Heating; Plasma confinement; Plasma materials processing; Steel; Testing; Tokamaks; Toroidal magnetic fields;

fLanguage

English

Publisher

ieee

Conference_Titel

Fusion Engineering, 1999. 18th Symposium on

Conference_Location

Albuquerque, NM

Print_ISBN

0-7803-5829-5

Type

conf

DOI

10.1109/FUSION.1999.849825

Filename

849825