A structural beam-based approach for preliminary structural sizing of toroidal coil system: A supplementary module to MADE algorithm

This paper presents a design tool for the preliminary structural sizing of the Toroidal Field (TF) coil system in a tokamak configuration. It is implemented as a dedicated add-on to the MADE (MAgnet Design Explorer) code, a design-space exploration algorithm for tokamak magnet windings. The selected case study is the Volumetric Neutron Source (VNS), a steady-state tokamak thought as an intermediate step between ITER and DEMO to support large-scale testing of tritium breeding blankets and other in-vessel components under DEMO-relevant neutron flux conditions. Here the approach represents the TF coils by beams, yielding a one-dimensional Finite Element model of the tokamak magnetic cage. Each coil is modelled by two coaxial beam lines representing the Winding Pack (WP) and the steel casing, thereby capturing their parallel mechanical response and the resulting load sharing. Electromagnetic loads derive from a Multiphysics workflow: source elements evaluate the magnetic field along a discrete coil centreline by the Biot–Savart law; the relevant Lorentz force and couple densities are transferred to the structural model on the same path. This framework enables efficient system-level analyses and fast parametric studies while preserving the dominant global stiffness contributions of the magnetic cage, yielding displacement predictions that agree with ITER-derived admissibility criteria within a few percent.