Journal of the Korean Physical Society

pISSN 0374-4884 eISSN 1976-8524


J. Korean Phy. Soc. 2006; 49(9(6)): 259

Published online December 20, 2006

Copyright © The Korean Physical Society.

Machining of the KSTAR TF Coil Structure

K. H. Hong, C. H. Choi, H. K. Park, J. W. Sa, H. T. Kim, H. Sin, J. S. Bak, J. Y. Song, Y. D. Chu, D. K. Hur, Y. G. Song, D. H. Park, S. H. Hwang, J. H. Lim, N. G. Kim J. H. Won and J. M. Chung


The KSTAR Toroidal Field (TF) magnet system consists of 16 TF structures. Each structure must be machined for precise assembly and reducing error field. Dimensions of the structure are a height of 4.5 m and a width of 3.2 m. The allowable tolerance of~the structure is $pm$1 $sim$ 2 mm, and that of the bolt hole for Poloidal Field (PF) coil basement is $pm$0.5 mm. The final machining of the structure is also important for assembly of extbf{ }the interface structures such as toroidal ring, PF coil structures, and Central Solenoid (CS) structure. Before coil encasing, the inside surface of the structure is machined. Most of the outer surface of the structure, except for the surface of the inter-coil structure (ICS), is machined after final welding. In particular, the side surface of an inboard leg, the connection plate of the ICS, the toroidal ring basement, the PF structure basements, shear key holes, and conical bolt holes are precisely machined. Fabrication and assembly tolerances are absorbed by the thickness of the electrical insulation, the spacer of the shear key, and the taper ring of the conical bolt. Six TF coil structures have been assembled and two structures are waiting for assembly.~ Another three structures are under final machining. A laser tracker is used for three dimensional survey and measurement of the structure.