Design and optimization of a magnet pole for Magnetic Resonant Imaging
Loading...
URL
Journal Title
Journal ISSN
Volume Title
Sähkötekniikan korkeakoulu |
Master's thesis
Unless otherwise stated, all rights belong to the author. You may download, display and print this publication for Your own personal use. Commercial use is prohibited.
Authors
Date
2018-06-18
Department
Major/Subject
Electrical Power and energy engineering
Mcode
Elec-3024
Degree programme
AEE - Master’s Programme in Automation and Electrical Engineering (TS2013)
Language
en
Pages
48+6
Series
Abstract
Magnetic resonance imaging (MRI) devices require a uniform magnetic field in the measuring area to capture the high-quality images. Permanent magnets are widely used as the main field source in the MRI devices. The field produced by such magnets is not uniform. Therefore, different field correction methods are usually employed to increase the uniformity of the magnetic field. In this thesis, a two dimensional (2-D) and three dimensional (3-D) numerical model of an MRI device is developed. The design and optimization of the poles for a low field MRI device is performed by using 2-D finite element (FE) method to increase the magnetic field uniformity. The pole faces are modelled by using non-uniform rational b-splines (NURBs). The particle swarm optimization algorithm is used to optimize the pole faces and magnet design of the MRI device. The optimization of different parameters of the pole surface is performed and compared for the homogeneity of the magnetic field in the measuring area. Finally, the best choice is made based on the field uniformity and minimum weight of the assembly. The final optimized design achieved from the 2D FE model is further compared with the 3D FE model. Moreover, the selected design is subjected to the sensitivity analysis to account for the magnetic field tolerances. Furthermore, the structural analysis is performed to take into account the effect of the stress ensuring that the designed structure is stiff enough to sustain the heavy mass without causing any deformation.Description
Supervisor
Belahcen, AnouarThesis advisor
Mukherjee, VictorKeywords
magnetic resonant imaging, particle swarm optimization, non uniform rational b spline, finite element method