Optimized HTS current leads

The problem of optimizing HTS current leads by varying their cross-section along the length is investigated both experimentally and numerically at 500 A current level. Bi-2223-based HTS multi-filament composite tapes were use d with two types of matrices: pure Ag and (Ag + 1 at. % Au) alloy. The warm ends of the HTS parts of the current leads were cooled with liquid nitroge n. Very low evaporation rates in the ease of Au-doped matrix and rather lon g time constants to reach thermal equilibrium were observed.