Theoretical concept and FEM simulations of improved shielding for round horizontal yokes for rotational power loss measurement

Stan Zurek

   The paper introduces a theoretical concept of a shielding for horizontal yokes for measurements of rotational power loss and other rotational and two-dimensional properties. Apart from horizontal parts, the shielding relies on vertical pieces distributed uniformly around the sample circumference, symmetrically on both sides. The simulations in 2D and 3D FEM show significant improvement in reduction of $H$ perpendicular to the sample surface ($H_z$). The gradient of the tangential $H$ is reduced so that the extrapolation of values towards the surface might be no longer required. There is also an added benefit that the required magnetomotive force is significantly lower (20-70\%) for achieving the same $B$ in the sample, as compared to the previously used simple horizontal shields.

Keywords: 2D FEM, 3D FEM, rotational power loss, magnetic shielding

[full-paper]