Performance Study of the NIMMS Superconducting Compact Synchrotron for Ion Therapy with Strongly Curved Magnets

Delivery of heavy ion therapy currently utilises normal conducting synchrotrons. For the future generation of clini- cal facilities, the accelerator footprint must be reduced while adopting beam intensities above 1 × 10¹⁰ particles per spill for more efficient, effective treatment. The Next Ion Medical Machine Study (NIMMS) is investigating the feasibility of a compact (27 m circumference) superconducting synchrotron, based on 90° alternating-gradient, canted-cosine-theta mag- nets to meet these criteria. The understanding of the impact of the higher order multipole fields of these magnets on the beam dynamics of the ring is crucial for optimisation of the design and to assess its performance for treatment. We analyse the electromagnetic model of a curved superconducting magnet to extract its non-linear components. Preliminary as- sessment is performed using MADX/PTC. Further scope, involving cross-referencing with other particle tracking codes, is discussed.