Winding Test Results of an Innovative Technique for Block Coil Curved Dipoles in the Development of a Gantry for Hadron-Therapy

The Superconducting Ion Gantry (SIG) project is the INFN (Istituto Nazionale di Fisica Nucleare) participation in the EuroSIG collaboration between INFN, CNAO, CERN and MedAustron. The EuroSIG main focus is on the exploration of new concepts and the prototype development of superconducting magnets used in hadron-therapy treatments. More specifically, in the SIG project, we are studying the most critical aspects of a 430 MeV/u superconducting carbon-ion gantry and particular attention is given to the design of 45-degree cosθ dipoles and the construction and testing of a 30-degree demonstrator. Although the baseline of the project is centered on cosθ-type magnets, we are working on an alternative strategy to mitigate the risk of failure in the construction of the demonstrator. This is a block coil type solution to avoid, with a simpler geometry, the difficulties of winding a curved cosθ dipole with significantly small curvature radius. In this context, an innovative winding technique was developed and tests have been conducted to confirm its feasibility. This contribution presents the results obtained from the winding tests in order to show the effectiveness of the method adopted to wind this type of coils and highlight possible improvements. In addition, an electromagnetic design concept for curved block coil dipoles has been developed, with the intention of proposing an optimized solution for the geometry of the coils, along with the method they can be wound.