학술논문

Investigating the Effect of Coil Length, Alignment Errors and Cooling Down on a Superconducting Magnet With Active Shielding for Rotating Gantry
Document Type
Periodical
Author
Source
IEEE Transactions on Applied Superconductivity IEEE Trans. Appl. Supercond. Applied Superconductivity, IEEE Transactions on. 34(5):1-5 Aug, 2024
Subject
Fields, Waves and Electromagnetics
Engineered Materials, Dielectrics and Plasmas
Magnetic fields
Force
Superconducting magnets
Magnetic shielding
Magnetic noise
Windings
Deformation
Active shielding
coil weight evaluation
FEM model
heavy particle radiotherapy
magnetic field calculation
rotating gantry
Language
ISSN
1051-8223
1558-2515
2378-7074
Abstract
A superconducting magnet with active shielding has been proposed for use in a heavy-ion beam rotating gantry in order to decrease weight. The magnet consists of two types of coils, dipole and active shielding coils, both of which are wound using Nb-Ti wires. In this study, three-dimensional coil configurations were designed, based on coil cross-sections designed in a previous study. Using the coil configurations, the magnetic field distribution in the longitudinal and radial directions of the coil and its peak magnetic field were calculated. The results indicated that the effect of the coil end section on magnetic field distributions became greater as the coil length becomes shorter. Also, the difference of the coil length has no impact on the peak field. In addition, the influence of coil alignment errors on the electromagnetic (EM) force, and that of cooling-down on coil deformation were investigated, using a coil cross-sectional model. As a result, EM forces caused by alignment errors of several mm in the shielding coil were negligible, compared to EM forces generated in the coil under a rated operation. Also, the maximum deformation of the coil cross-section was a few millimeters when the coil was cooled from 300 K to 5 K.