An investigation was made of the influence of mechanical strain upon the critical current for MgB2/SUS316 superconducting tapes. The tensile axial strain along the tape length was successfully introduced into the sample by using a U-shaped holder made of stainless steel (SUS304). Two samples were examined at 4.2K and 5T (B was applied perpendicular to the tape surface). The JC–strain relationship could be divided into 2 regions. Rapid and large degradation occurred at a strain which exceeded ~0.5%. On the other hand, the JC change was reversible for strain changes of between -0.4% (compressive strain) and 0.4%. The JC increased and decreased with increasing and decreasing external strain in this region, respectively. The TC value also changed with changes in the external strain. The TC increased with increasing external strain. The reversible change in JC originated in the change in TC.

Critical Current of Magnesium Diboride/Stainless Steel Composite Tapes Under Tensile or Compressive Strains. H.Kitaguchi, A.Matsumoto, H.Hatakeyama, H.Kumakura: Superconductor Science and Technology, 2003,16, 976-9