Transport current distribution on Nb3Sn strand for TARSIS

• We develop an improved scheme for the intrinsic mechanism in TARSIS.
• Microscopic transport map characterizing the inter-filament transfer is given.
• V–I characteristic within a wide resistive range is revealed.
• These results are helpful for future strand experimental design.

Recently TARSIS measurements (Test Arrangement for Strain Influence on Strands) have been conducted for Nb3Sn strand’s critical current Ic under periodic bending strain, to stimulate the real situation in operating CICC. Based on the Ciazynski and Torre’s formulae (Supercond. Sci. Technol. 23, 2010), we propose an improved scheme, further revealing the intrinsic mechanism for TARSIS. Especially the obtained transverse transport map well characterizes the inter-filament transfer, which shows clearly two pathways of the electric field and the filament twist dependence of the current. Meanwhile, the improved scheme is extended to describe the generalized transport properties, and predict V–I characteristic within a wide resistive range. The V–I curves illustrate the shift from typical power law behavior to less precise power law behavior with loading increasing. These results are helpful for future strand experimental design.