2019/10/28 by Vasily Marusov, Marusov, Vasily
Engineering · Materials Science · Physics and Astronomy · #Accelerator Physics (physics.acc-ph) #Computational Physics (physics.comp-ph) #Electric Motor Design and Analysis #FOS: Physical sciences #Magnetic Properties and Applications #Non-Destructive Testing Techniques #physics.acc-ph #physics.comp-ph
paper · pdf · doi:10.48550/arxiv.1910.12696
4 pages
arxiv created 2019/10/28 · openalex publication_date 2019/10/28 · arxiv updated 2019/10/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
FEM simulations are a standard step in the design of accelerator magnets. It is custom for accelerator applications to characterize the field quality in terms of field expansion coefficients. With a commonly accepted approach, expansion coefficients are calculated by means of a Fourier transform of the local FEM solution at points on an arc. The accuracy of the coefficients calculated this way depends strongly on the FEM mesh configuration and simple refinement of the mesh does not always improve accuracy. The accuracy of the expansion coefficients calculation can be improved by using the data on the magnetization of elements in the magnet yoke, obtained in the solution, instead of using directly the local solution. Since currents and the yoke magnetization are the only sources of the field, with these data the field expansion coefficients can be calculated at any remote point. We derive closed forms for calculating expansion coefficients and implemented these results in the ANSYS add-on. Results for a case study are presented, which demonstrate that expansion coefficients can be calculated with good accuracy even for a rather coarse mesh.