THE OPTIMIZATION DESIGN AND ANALYSIS ON 3rd POLOIDAL FIELD COIL FEEDER OF ITER

摘要

The ITER experimental device contains very large and powerful magnets to generate, stabilize and control the deuterium-tritium plasma for thermo-nuclear fusion. The ITER feeder systems connect the ITER magnet systems located inside the main cryostat to the cryo, power-supply and control system interfaces outside the cryostat. The main purpose of the feeders is to convey the cryogenic supply and electrical power to the coils as well as house the instrumentation wiring. In total there are 31 such feeders, 9 for the TF (toroidal field) magnet system, 6 for the PF (poloidal field) magnet system, 6 for the CS (central solenoid) modules, 5 for the CC (correction coil) systems, 3 reserved exclusively for the supply of cryogens to the TF coil structure cooling systems and 2 for coil instrumentation. Most importantly the feeders include the Coil Terminal Box (CTB), the S-Bend Box (SBB), the Cryostat Feed-through (CFT), In-Cryostat-Feeder (ICF). The Feeder carries superconducting busbars, supercritical cryopipes and instrumental pipes from the CTB to the coil. The busbar which carries strong current will suffer from high Lorentz force due to the background magnetic field inspired by the coils and the self field induced by adjoining two busbars. Peak magnetic force could be in the ICF region that requires dense supports; in the CFT and SBB, the force is not as high as in the ICF, but to minimize the heat load to the busbar, as well as the containment ducts and separate plate, fewer and weaker support design is proposed. This paper summarizes the detail design of the PF3 feeder system, and also includes a main description of the structure analysis on PF3. This analysis aims at the support system; to get real magnetic force load in the worst scenario, an electric-magnetic coupled analysis which includes the busbar and the coils is performed, then the force result is imported into the mechanical analysis, applied on the busbars, meanwhile the supports and the containment duct are contained in the model to check the full system performance under Lorentz forces, earth gravity and thermal contract at low temperature as 4.5K. Then the optimization of PF3 detail design on positions & numbers of busbar supports and gambles can be reached to meet the requirement of ITER DDD 11 Magnet, which is useful to improve the final design and mass production of PF3 feeders.