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The closed electric circuit concept is used for critical current and stability measurements of [Nb.sub.3]Sn multi-strand superconducting cables. Significant degradation is observed in the critical current of the cable when the average compressive stress is about 20 MPa, which is found to be irreversible after unloading.

The article examines the degradation due to transverse loading under high magnetic field. Findings reveal an irreversible degradation due to compressive stress of around 30 MPa.

A cryogen-free 19 T superconducting magnet with a 52-mm room temperature bore is developed. The mechanical properties are investigated for oxide superconducting Bi-2223 tapes.

The deformation and fracture behavior is studied in Sm123 bulk superconductors by comprehensive loading at room temperature. The effects of specimen length on the compressive mechanical properties are discussed.

Melt-processed bulk superconductors are used to construct a superconducting permanent magnet system.

Vickers hardness characteristics of bulk superconductors are examined at cryogenic temperatures.

The influence of magnetic fields on the mechanical properties and strain/stress dependence of the critical current of Nb-matrix Nb3Sn multifilamentary wires is studied by means of an axial tensile testing apparatus. Results show that the strain sensitivity of the critical current is the same as the reversible strain limit. The data also suggest that the wires are highly tolerant to external stress/strain.

The effect of residual strain on the critical current flow in bronze processed multifilamentary Nb3Sn superconducting wires reinforced with CuNb is studied by means of an estimation technique based on the rule of mixtures. Results show that the effect of residual strain on the critical current denity of the wires is negligible and fundamentally similar to that of monolithic wires.

Multifilamentary [(Nb, Ti).sub.3]Sn superconducting wires with reinforcing stabilizer of CuNb composite, CuNb/[(Nb, Ti).sub.3]Sn, were developed. The outstanding point is that the 0.2 % proof stress at 4.2 K in CuNb/[(Nb, Ti).sub.3]Sn was extremely improved to 320 MPa even after the heat treatment at 670 [degrees] C for 192 hours, which is 1.8 times higher than that in ordinary Cu/[(Nb, Ti).sub.3]Sn. The overall [J.sub.c] value in CuNb/[(Nb, Ti).sub.3]Sn was obtained to be 110 A/[mm.sup.2] at 16 T and 4.2 K. These results show that the bronze processed multifilamentary [(Nb, Ti).sub.3]Sn superconducting wire with CuNb reinforcing stabilizer is actually employable for a high field superconducting magnet.

The development of a multifilamentary Nb3Sn wire containing a copper niobium (CuNb) stabilizer is reported. Fabricated via the bronze process, the Nb3Sn/CuNb wire's electrical characteristics at 23 T and 4.2 K include a residual resistance ratio of 20 and a 0.2-micro-ohm.cm magnetoresistance. Its mechanical strength and superconducting properties suggest that it is suitable for use in high-field superconducting magnets

A method for the reduction of finite pole length effect that is characteristic in the conventional heads, has been described by the addition of new low permeability magnetic layers. The function of the layers was confirmed by finite element analysis and trial manufacturing. The improved heads are expected for the higher magnetic recording density.