Speaker
Description
In pursuit of enhanced beam current and spatial efficiency in high-intensity cyclotrons, this study investigates a novel accelerator concept: the use of multiple axially separated orbits (multi-plane) operating under a common magnet system. A key challenge in such a configuration is maintaining isochronism across distinct axial planes, which critically depends on the uniformity of the magnetic field in the vertical z direction. This work presents a theoretical framework and numerical modeling approach to quantify the magnetic field uniformity requirements necessary to preserve isochronous conditions for multi-plane orbits.
Using COMSOL Multiphysics, we construct a parametric 3D static magnetic field model of a symmetric dipole magnet, incorporating realistic pole shapes and excitation coils. Field distributions are evaluated on three parallel orbit planes (z = −Δz, 0, +Δz), and the deviation of magnetic induction δB(z)=(Bz−B0)/B0 is analyzed as a function of radius. Based on classical isochronous criteria, a quantitative threshold for the vertical field gradient ∂B/∂z is derived to ensure phase stability within ±10⁻³ relative deviation.
This study provides design guidelines and performance limits for implementing synchronized multi-plane orbit systems within a single magnet, offering a pathway toward compact, high-current cyclotron architectures.
