Figure 6
From: Characteristics and FEA verification of the attraction between like magnetic poles
The FEA simulation shows the self-demagnetization and the EE vs. magnet length for a series of stand-alone N55 magnets with the same diameter and five lengths. The Bz vs. x of D32 × 2 is shown in (a), and the Bz vs. x of D32 × 10 is shown in (b). The EE values vs. magnet length and distance are shown in (c), and EE is defined as the difference between the maximum Bz and the center Bz over the center Bz on the curve of Bz vs. x: \(EE\, = \,\left( {B_{{\text{z@max}}} \, - \,B_{{\text{z@center}}} } \right)\,/\,B_{{\text{z@center}}}\). When the maximum Bz is at the center, the EE becomes zero. The EE is 2.4 for the magnet of L = 2 mm, meaning the edge’s maximum Bz is 240% higher than that of the center Bz. The 2D Bz maps at the cross-section through a diameter of the three magnets are shown in (d), in which the center Bz of 0.35 T at L = 10 mm is over four times the center Bz of 0.08 T at L = 2 mm.
