Transport Properties of a PIT- ${\hbox {Nb}}_{3}{\hbox {Sn}}$ Strand Under Transverse Compressive and Axial Tensile Stress

A study of the critical current of a PIT strand under transverse compressive and axial tensile loads is presented. The conductor is not reinforced and has a proof strength, , of 142 MPa. Although the tensile strain at the maximum of the critical current, , is only 0.14% (low thermal precompression) the strand behaves as expected. However it is particularly sensitive to transverse compressive forces. Even relatively small forces yield to a reduction of the critical current. Qualitatively this degradation may be explained by a non-uniform deformation of filaments, yielding to irreversible micro cracks, and by a reduced of intact filaments. The recovery of upon unloading of the transverse compressive force has also been investigated.