The ASDEX upgrade TF coils: design to acceptance

The design essentials of the toroidal-field (TF) coils for ASDEX upgrade (AU) are summarized. The AU tokamak is a fusion experiment with a poloidal divertor. Its main goals are to simulate reactor-type plasma-wall interaction with a magnetic-field configuration compatible with reactor requirements, i.e. the poloidal field (PF) and control coils outside the TF coils. The resulting plasma cross sections of the single-null (SN) and double-null (DN) divertor configurations are highly elongated in this case. Consequently, the familiar constant-tension D-shape was chosen for the TF coils to produce at the plasma center a flux density of up to 4 T. Stress computations and mechanical testing are also reviewed and the manufacturing experience gained from three completed and five assembled coils is sketched.<
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