Optimization Design of High-Performance Hybrid Superconducting ECR Ion Source Magnet System Based on Particle Swarm Algorithm

The development of 18 GHz hybrid superconducting ECR ion sources is constrained by the complex trade-off in magnet system design, where achieving simultaneous excellence in field strength, confinement stability, and resonant coupling remains a formidable challenge. A design automation framework that tightly integrates Particle Swarm Optimization (PSO) with COMSOL-based finite element analysis is presented. This synergy enables the global optimization of the permanent magnet hexapole and the superconducting solenoids’ currents as an interconnected system. The optimizer delivers a magnetic field configuration that simultaneously achieves a 2.6 T axial peak, a 4.25 mirror ratio, and a precise minimum-B field of 0.6 T. This synergy creates a stable magnetic cage perfectly resonant at 18 GHz, ensuring superior plasma confinement and efficient microwave-to-plasma energy transfer. This study validates the PSO algorithm as a powerful tool for transcending conventional design paradigms in complex electromagnetic systems. The resulting magnet solution not only meets the stringent demands of next-generation ECR ion sources but also provides a transferable blueprint for optimizing a broad class of symmetric devices governed by multi-physics constraints.