Test of a curved Discrete Cosine-Theta superconducting magnet for Ion-therapy

This paper presents the design and testing of a curved Discrete Cosine-Theta (DCT) superconducting magnet, developed through a collaboration between the Institute of Modern Physics and Lanzhou Ion Therapy Co., Ltd. The magnet is intended for use in compact, lightweight gantries for ion-therapy. It consists of four NbTi DCT layers, generating a 2 T dipole field within a 100 mm clear bore. The design features a bend radius of 0.8 m and a magnetic bend angle of 30 degrees. The magnet underwent extensive testing, including quench training, magnetic field measurement, and strain analysis, all conducted during initial operation in liquid helium. Additionally, discrepancies between the design parameters and experimental measurements were analyzed, and potential causes of quenching were investigated. Based on the findings, recommendations for machining and testing improvements are proposed to enhance the performance and reliability of this type of magnet.