Study on the model of space magnetic induction of a bi-pole magnet

Abstract


Fig. 1 .
Fig. 1.Schematic diagram of a cylindrical magnet with multiple local demagnetization on the surface.

Fig. 2 .
Fig. 2. (a), (b) Normal magnets of size and under magnetic field viewing film; (c) the small magnet is observed to be attracted to the center of the large magnet after the local demagnetization process at the center of the large magnet; (d) experiment setup for the measurement of magnetic induction intensity.

Fig. 5 .
Fig. 5. (a) The axial magnetic induction intensity for the abnormal magnet.Red dot denotes the experimental data whereas the blue line denotes the theoretical results.(b) The axial magnetic induction intensity of a normal cylindrical magnet, an abnormal magnet and a normal ring magnet, of which the dimensions of the three are the same.
Fig. 6.Model B: Cylindrical magnet with local demagnetization at both the center and the orbit: (a) Diagram of the abnormal magnet.For the convenience of reading, the radii of the four small circles in the figure are doubled.(b) The abnormal magnet under magnetic field viewing film.
Fig. 7. (a) Experimental data of axial magnetic induction for abnormal magnets of type A and B; (b) the axial magnetic induction intensity of the abnormal magnet of type B. Blue circle denotes the experimental data whereas the red line denotes the theoretical results.

Fig. 8 .表 2
Fig. 8. (a) The horizontal magnetic induction intensity of the abnormal magnet of type B at .Red circle denotes the experimental data whereas the blue line denotes the theoretical results.(b) Comparison of horizontal magnetic induction intensity of the abnormal magnets of type A and B and a normal magnet with the same size at .

Fig. 9 .
Fig. 9.The axial magnetic induction of larger magnet demagnetized by smaller magnets of different heights with (a) , , and (b) , , .

Fig. 10 .
Fig. 10.Abnormal magnets C, D are locally demagnetized by smaller magnets of size and at the center, the difference of magnetic induction between C and D at the plane away from the abnormal magnets' surface: (a) The tangential difference ; (b) the axial difference ; (c) the difference of absolute value .

Table 1 .
Material parameters of the two models.