Polygonal Halbach Array for Low-Field Portable MRI

Motivation: The cross-section of layered Halbach arrays should be versatile for performance optimizations and to accommodate different applications for dedicated MRI. However, it has not yet been systematically investigated. Goal(s): To develop a formula for magnet polarizations in polygonal Halbach arrays for performance optimization. Approach: A formula deciding the magnet polarization of polygonal Halbach arrays was proposed and tested. A hybrid array, combining polygonal and circular cross-sections, was optimized using a genetic algorithm. Simulations were done using MagTetris. Results: Polygonal arrays achieved stronger, more homogeneous fields than circular arrays. A hybrid array increased field strength by 2.11% and homogeneity by 84.83% over circular-only arrays. Impact: This study lays the groundwork for optimizing layered Halbach arrays with unexplored polygonal and hybrid shapes that achieve stronger, more homogeneous fields. A formula for versatile cross-sections enables further innovation in magnet array designs.