Modular Spherical Magnetic Field Sensor Array

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.