Stress and strain effects of Nb/sub 3/Al conductors subjected to different heat treatments

Uniaxial stress (strain) tolerance was examined for the jelly-roll processed RHQT Nb/sub 3/Al multifilamentary wires made by the LTDR, RHQT and TRUQ methods, respectively. There is almost no difference in the stress (strain) tolerance between the three methods, and the degradation of B/sub c2/ under the stress at 500 MPa at t=0.73 and b=0.8 was about 3.2%. The less dependence of the stress (strain) tolerance on the conductor processing suggests that excellent strain tolerance may be an essential advantage of Nb/sub 3/Al over Nb/sub 3/Sn. The stress dependence of B/sub c2/ in TRUQ method Nb/sub 3/Al at 4.2 K was calculated, and the degradation of B/sub c2/ under the stress of 500 MPa was estimated at only 1.5%. Therefore, the high stoichiometry achieved in the Nb/sub 3/Al conductors is compatible with greatly improved high-field properties.