The simulation and numerical analysis for ITER first PF(poloidal field coil) feeder

The ITER feeder systems connect the ITER magnet systems located inside the main cryostat to the cryo-plant, 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. The Feeder carries superconducting busbars, supercritical cryo-pipes and instrumental pipes from the CTB to the coil. The PF busbar which carries 52kA current will suffer from high Lorentz force due to the background magnetic field inspired by the coils and the self field between every pair of busbars. Peak magnetic force could be 6tons/m in the ICF region that requires dense supports. But to minimize the heat load to the busbars as well as the cryo-pipes, fewer and weaker supports design is proposed, so a balance between mechanical strength and thermal insulation performance should be achieved. This paper presents the simulation and analysis on support system design for ITER 1st PF feeder including the S-Bend Box (SBB), the Cryostat Feed-through (CFT), the In-Cryostat-Feeder (ICF), especially for a pair of busbars and main cooling-pipes firstly. This analysis aims to get real magnetic force load under the worst scenario, an electric-magnetic coupled analysis which includes the busbars and the coils is performed, then the Lorentz force result is imported into the mechanical analysis, applied on the busbars, meanwhile the supports and the containment duct are contained in the finite element model (FEM) to check the full system performance under Lorentz forces, earth gravity and thermal contract at 4.5K. Based on the simulative and analytical results, the quantity and the spaces between supports in the 1st PF feeder have been studied and the detail design optimized.