Design Considerations of 2-D Magnetizers for High Flux Density Measurements.

A 2-D magnetizer introduces variation in the flux density $(B)$ across the sample under rotational magnetization. This variation requires additional energy requirements that limits the attainable aspect ratios, flux density levels and stresses the supply. A numerical methodology that accounts for the flux leakage and the eddy currents is proposed to analyze uniformity and variation in $B$ in four 2-D magnetizers. The analysis was done beyond the knee of the magnetization curve. Numerical results will show that round magnetizers can mitigate the variation of the square magnetizer by over 92%, by making the MMF more sinusoidal and equalizing the reluctance along the airgap. In addition, deeper yokes minimized the variation by about 50% in the square and the Halbach testers. The results of this analysis was a design that mitigates the variation in $B$ by a combination of sinusoidally distributed windings, and a deep yoke. The proposed magnetizer achieved very high flux densities over a relatively wide frequency range, which were 2.04 and 1.69 T at 60 Hz and 1 kHz, respectively. [ABSTRACT FROM PUBLISHER]