Hysteresis losses in superconductors with an out-of-phase applied magnetic field and current: slab geometry
Abstract:We calculate the hysteresis losses in the slab geometry configuration for an applied magnetic field and current with a phase shift between them. The result leads to maximum losses with the field and current in phase and minimum losses at a phase shift of /2. Although until now we have had no explanation of some experimental results suggesting a shift for both these extreme values, the dependence on the phase shift of the calculated ratio between the minimum and maximum losses is in good agreement with these results. Therefore, they can be used in a first approximation for designing magnetic systems with high-Tc superconductors for those AC applications in which phase shift can occur. In addition, it is emphasized that the results can be very different, depending on the form of the temporary change of the applied field and current, in contradistinction to the case of applying only the field or current. A linear temporary change is given as an example, which demonstrates that the loss decrease at non-zero phase shift can be considerably higher than for the sinusoidal field and current change.
Document Type: Research Article
Publication date: December 1, 2007