International Journal on Magnetic Particle Imaging IJMPI
Vol. 11 No. 1 Suppl 1 (2025): Int J Mag Part Imag
https://doi.org/10.18416/IJMPI.2025.2503054
Modular Spherical Magnetic Field Sensor Array
Main Article Content
Copyright (c) 2025 Jan-Philipp Scheel, Eric Aderhold, Janne Hamann, Mandy Ahlborg, Matthias Graeser

This work is licensed under a Creative Commons Attribution 4.0 International License.
Abstract
The characterization of magnetic field properties is an important task in magnetic imaging modalities.
Emerging multi-coil field generator topologies, generating the gradient field in magnetic particle imaging, pose new challenges.
If multiple coils are active, obtaining the current to field relation is not trivial, due to cross-coupling and cross-saturation effects.
Singular measurements at certain operating points are not sufficient for a full system description in these non-linear systems.
In this work, an adaptable measurement prototype which utilizes multiple magnetic field sensors is presented.
The developed device consists of three-axis Hall-sensor ICs located on a spherical surface.
Utilizing the solid spherical harmonic expansions the field inside the sphere can be approximated.
The combination of high measurement accuracy, straightforward measurement procedures, and modularity enables rapid and reliable measurements.
Article Details
References
International Journal on Magnetic Particle Imaging IJMPI,
pp. Vol. 10 No. 1 Suppl 1 (2024): Int J Mag Part Imag, 2024.
[2] F. Foerger et al. Flexible selection field generation using iron core coil arrays.
International Journal on Magnetic Particle Imaging IJMPI,
pp. Vol 9 No 1 Suppl 1 (2023), 2023,
doi:10.18416/IJMPI.2023.2303023.
[3] M. Boberg et al. Reducing displacement artifacts by warping system matrices in efficient joint multi-patch magnetic particle imaging.
International Journal on Magnetic Particle Imaging,
pp. Vol 6 No 2 Suppl. 1 (2020), 2020,
doi:10.18416/IJMPI.2020.2009030.
[4] M. Boberg et al., Unique compact representation of magnetic fields using truncated solid harmonic expansions, 2023.
arXiv: 2302.07591[physics].
[5] F. Foerger et al. Single-shot magnetic field measurements for MPI.
International Journal on Magnetic Particle Imaging IJMPI,
pp. Vol. 10 No. 1 Suppl 1 (2024): Int J Mag Part Imag, 2024.
[6] E.Aderhold et al. Spherical magnetic flux density sensor array.
Transactions on Additive Manufacturing MeetsMedicine,
6:1863, S1 2024,
doi:10.18416/AMMM.2024.24091863.