Inter-Tape Contact Resistance Characterization of Soldered Stacked-Tape Cable Samples in Liquid Nitrogen

We experimentally measured and numerically modeled inter-tape contact resistance in reduced-scale soldered tape stacks. Nine cable-type specimens—seven 30 cm-long samples with 30 or 69 of 4 mm-wide REBCO tapes and two 100 cm-long samples with 104 and 106 of 12 mm-wide tapes—were manually fabricated using pre-cut long REBCO tapes to facilitate four point voltage measurements. Measured inter-tape resistivities ranged from 30 nΩ·m to 733 nΩ·m, with the best soldered stacks averaged 47 nΩ·m whereas the unsoldered and poorly soldered cases averaged 516 nΩ·m and 683 nΩ·m. A two-dimensional finite element model assuming perfectly aligned tapes and tunable sol der resistivity reproduced these trends, confirming the dominant role of edge-solder conductivity in reducing contact resistance. Cross-sectional microscopy corroborated the link between solder distribution and electrical performance, show…