Critical currents of Nb3Sn wire subject to applied transverse stress

We investigated the influence of transverse stress on the critical current, I_c. We tested a Nb₃Sn, wire fabricated thorough the powder-in-tube route, mainly at 16 K and 2 T. In the stress window of 0-42 MPa, a reversible relation was confirmed between I_c and the compressive stress, σ_t. After a slight increase of I_c at very small σ, I_c decreases with further increase of σ_t. When we unloaded within this stress window, I_c recovered to its virgin loading curve. I_c is more sensitive on σ_t in this work than in the I_c-σ_t relations reported so far. This can be attributed to the lower B_c2 at 16 K (3.8 T by Kramer´s extrapolation) and possibly a nonuniform stress distribution in the present work. σ_t greater than 49 MPa caused an irreversible I_c degradation due to a plastic deformation of the filaments.