Electromagnetic and Thermal Properties of HTS Bulk Combined With Different Ferromagnetic Structures Under Pulsed Field Magnetization

Comparison of the Field Trapping Ability of MgB2 and Hybrid Disc-Shaped Layouts

“…However, in agreement with [ 31 , 32 ], the addition of an FM layer also produces a strong decrease in the trapped magnetic flux density near the surface covered with the FM layers of layouts geom2 , geom3 , and geom5 . In these samples, deterioration of the field-trapping ability of up to 74, 81, and 58%, respectively, was observed, as shown in Figure 13 , where the values are plotted as a function of the radial position (a) and the 3D maps of the magnitude of trapped field are depicted for geom2 (b), geom3 (c), and geom5 (d).…”

“…Starting from the layouts and results reported in [ 31 ] by Philippe et al, and in [ 32 ] by Li et al, we applied the as-validated model to the study of new hybrid configurations of MgB 2 -soft iron. In Figure 11 , the cross-section of the investigated layouts is depicted.…”

“…The dependence of the trapped flux density on the radial position was assessed at 1 mm above the top surface and 1 mm below the bottom surface of all the hybrid arrangements. This choice was made in order to enable a coherent comparison with data reported in the literature [ 31 , 32 ], and takes into consideration that the qualitative behaviour of the trapped field profiles remains unaffected and that the samples’ performances vary only between 1 mm and 1.5 mm, which is the minimum distance reached in the experiment (see previous sections).…”

“…The results are partially comparable to those obtained in the literature for similar hybrid configurations. Specifically, in references [ 32 , 48 ], slight improvements were reported for all the proposed hybrid configurations, including the configurations we defined as geom1 and geom3 . This different behaviour could likely be attributed to the superior initial performance of the MgB 2 magnet compared to that obtained with YBCO magnets, which could make the role of the FM layer not so effective for these configurations.…”

“…By way of example, trapped field values of 2.12 T were achieved at 5 K (measured above a disc-shaped sample with a radius R = 9 mm and a height h = 6 mm) [ 28 ], 2.4 T at 15.9 K (measured above a disc-shaped sample with R = 15 mm and h = 6.6 mm) [ 29 ], and 3.2 T at 15 K (measured above a disc-shaped sample with R = 10 mm and h = 1.6 mm) [ 30 ]. On the other hand, soft ferromagnetic materials and alloys with high saturation field and magnetic permeability are good candidates for assembling hybrid superconducting/ferromagnetic magnets [ 31 , 32 ].…”