A magnetically compatible, arbitrary positioning system for accurate spatial mapping of magnetic fields for shimming...

After the fabrication of magnetic resonance superconducting magnets, the magnetic field inhomogeneity needs to be accurately measured for subsequent shimming. However, conventional measurement methods are susceptible to magnetic fields, have poor compatibility, and are difficult to adapt to various types of magnets. This paper proposes a new field measuring system based on a three-axis movable platform. The system utilizes non-magnetic materials and an innovative hand-wheel lifting design that can be adapted to various aperture magnets, thus obviating the necessity for electrically driven equipment and addressing safety concerns in strong magnetic fields. In addition, the measurement system offers high accuracy up to 1 mm and a wide measurable range. The fields of 3 T and 7 T magnets were mapped using the designed system with diameter of spherical volume (DSV) of 160 mm and 130 mm, respectively. Experimental results demonstrate that the magnetic field measurement system has strong compatibility and can accurately map the magnetic field at arbitrary positions, which is critical for shimming studies.