Evaluation of field quality for curved magnets

Measuring and evaluating the field quality of strongly curved magnets, which play a crucial role in beam transmission, pose challenges for both design and experiment process. This study introduces a surface fitting method that utilizes Neumann boundary data to reconstruct the inner magnetic field, reducing uncorrelated point-to-point noise. The proposed mathematical procedure is supported by data verification of modeled coils, offering accurate magnetic field and precise transfer maps for beam physics applications. By combining the method with measured data from Hall sensors using Bayesian inference, the accuracy of extracting the coefficients of the field representations in measurement can be enhanced.