A procedure for axisymmetric winding design under parametric constraints: An application to the RFX poloidal transformer

The problem of winding design to perform a specified field synthesis is usually carried out as analytic determination of current distribution within a given region. This approach may be useful for conceptual or preliminary design, but presents severe technical difficulties from a construction point of view. A construction oriented procedure for axisymmetric air core windings for fusion devices has been developed, to account for parametric constraints such as current per turn, current density, number of turns and diagnostic accessibility. Starting from a preliminary tentative design, presenting suitable electrical parameters, each coil position is automatically adjusted, within specified limits, to achieve the required field synthesis. A package has been implemented and succesfully applied to the RFX [1] Poloidal Field Transformer design and the main results are reported in the paper together with a number of numerical examples.