Fig. 7.

||B⃗|| (top) and ||E⃗|| (bottom) maps on the central axial planes (i.e., z = 0 mm) in air for the physical coil and the three numerical model S2, G32, and H16. The ξ (SMAPE) maps (equation 5) are reported on the right side of the field maps. On the right, the calculated ξ̄ (equation 6) and the relative standard deviation are reported for the five axial and three coronal planes measured. In all the planes, ||B⃗|| of the physical coil was well replicated by the three computational models with ξ̄ always less than 11 %. In the central axial plane, only the S2 model was able to replicate the ||E⃗|| peak due to the ports position, whereas the G32 showed a uniform ||E⃗|| and the H16 model was highly affected by the multiport excitation - increasing the ξ̄ of the plane up to 45 %