Self-Consistent Current Density Calculation for HTS Coils

The maximum current that a high-temperature superconducting (HTS) coil can achieve is typically calculated assuming uniform current density within the tape in the presence of a flux density gradient within the coil. This solution is not consistent with the current density and flux density, or , dependence of the HTS tapes and more current flows in areas of lower magnetic flux density. For some designs, this error is small, but it can be significant in other cases. This paper presents a method for computing the self-consistent critical current distribution within an HTS by imposing the condition that there is no voltage gradient across the width of an individual tape. The expected increase in critical current is predicted to be as high as 25% for some cases.