Illustration of the tools used to heat treat the sample (up to ), apply the bending strain (at room temperature), and measure its transport critical current (at 4.2 K).
Electric field vs current (in double-log scale) measured at temperature and magnetic field . For each sample type, three curves relative to three different voltage tap pairs are plotted.
Critical current values measured at 4.2 K as a function of the magnetic field for the reference samples ( curve) and for TW and UNTW samples subject to either 0.25% (closed symbols) or 0.5% (open symbols) peak bending strain. The dotted lines are guides only for the eyes, while the solid line is a fit for the reference samples according to Durham’s scaling law (Ref. 13 ) under the assumption of an axial thermal prestrain .
Electric field vs normalized transport current plotted in a double-log scale. Measurements performed at 14 T background field are reported for all the reference and bent samples of both the UNTW and TW types.
Transition -index determined for the measured samples at different magnetic fields as a function of the transport critical current. The lines are fits according to the characteristic power law (Ref. 15 ).
Critical currents measured on bent strands for the cases of and , which are normalized to the critical current of the reference samples . The experimental points are compared to the lines computed with Ekin’s model. The solid lines are computed in the long twist pitch limit, while the dashed ones are calculated in the short twist pitch limit.
Parameters derived from the distribution analysis (Ref. 16 ) at .
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