Repeatability of magnetic field homogeneity and temperature stability in a 47mT Halbach array measured by an open-source field mapping robot

Motivation: Lab-scale magnet construction and optimization at low fields (< 1T) depends significantly on the magnetic field mapping robot for characterizing the magnet's homogeneity and stability. This is important because low-field magnets are more susceptible to environmental variations than well-insulated superconducting magnets. Goal(s): To establish the performance of the home-built field mapping robot and evaluate the repeatability of a 47mT Halbach scanner's magnetic field homogeneity. Approach: We assessed the robot's spatial accuracy and characterized a Halbach system for spatio-temporal repeatability in magnetic field strength and bore temperature, simultaneously. Results: The robot accomplished sub-millimeter accuracy and the repetability experiments demonstrated a CV < 5%. Impact: The homemade mapping robot provides accurate and simultaneous multi-parameter mapping useful for characterizing low-field magnets. The repeatability and stability of the magnetic field strength of the Halbach scanner indicate consistent scanner operation, which is essential for portable low-field scanners.