This note presents the use of magnetic field analysis to obtain the AC loss in a superconductive filament.
Table 1 shows the average AC loss per meter in the longitudinal direction when applied current is between 50 and 80 % of critical current. Figure 1 and Figure 2 show the AC loss over time.
The AC loss caused by magnetic hysteresis inside the superconductor varies with the amplitude of the applied current.
Current Density Distribution
Figure 3 and Figure 4 show the current density distribution of a normal conductor and a superconductor, respectively , when 80% of critical current is applied. The +Z direction is a positive direction of applied current amplitude.
The applied current amplitude is maximized at 0.025 seconds. At this time, the current flows uniformly in the normal conductor. Meanwhile, the current flows toward both sides in the superconductor. This non-uniform current distribution is the cause of the greater loss.