Strain dependence of critical current associated with constitution of practical Nb3Sn superconducting wires.

Experimental Verification of the Temperature and Strain Dependence of the Critical Properties in Nb3Sn Wires

The critical current density in NbJSn conductors is described with an improved scaling formula for the temperature, magnetic field and strain dependence. In an earlier study it is concluded that the largest uncertainties in this description arise from the temperature dependence that is described with various slightly different empirical relations. For the optimization of the numerical codes, us...

Transport and magnetic critical current in superconducting MgB2 wires

Direct comparison of the magnetic and transport critical current density (Jc) for the same pieces of copper-sheathed MgB2 wires shows a large discrepancy in magnitude and field dependence of the two. The value of magnetic Jc can differ from the value of transport Jc by a factor of 10 or more. This discrepancy does not occur merely because of the difference in the voltage at which the magnetic a...

In-situ neutron diffraction study of a heating treatment for Nb3Sn ITER superconducting wires

In-situ powder neutron diffraction studies have been performed during the heating treatment of a set of Nb3Sn wires obtained by the internal tin process. The different phases appearing during the process have been evidenced. A strong reorientation of the deformed copper and niobium metals induces an orientation on the Nb3Sn formed. Among the phases formed, the δ-CuSn phase is decomposed at 890K...

Critical-current reduction in thin superconducting wires due to current crowding

Strain-dependence of the superconducting critical temperature Tc in Al and Nb based on ab-initio methods

In the past 20 years, considerable efforts have been devoted to the construction of engineering equations that can predict the critical current density Jc of practical Nb3Sn superconducting wires for high-energy physics and medical applications. Early studies concentrated on the Jc-dependence on temperature, T, and magnetic field, H. The need to adopt Nb3Sn wires for higher-field applications h...