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The race-tract magnets using F1 Rutherford cable (Cu stabilized [Nb.sub.3]Al strands) are tested and their quench characteristics are studied. The advantages and disadvantages of these Rutherford cables containing [Nb.sub.3]Al strands re discussed.

The extent to which the matrix ratio can be reduced for the rapid-heating, quenching and transformation (RHQT) [Nb.sub.3]Al wires is discussed. The non-Cu [J.sub.c] is improved by about 20% by the reduction of the matrix ratio when compared to conventional [Nb.sub.3]Al wires.

The characteristics of the [Nb.sub.3]Al strand through the rapid heating/quenching and transformation (RHQT) process are described. The studies have shown that the copper stabilized RHQT-processed [Nb.sub.3]Al strands can be used for application in high field accelerator magnets at 4.2 K.

A low-matrix-ratio [Nb.sub.3]Al wire is fabricated and the effects of the rapid heating/quenching (RHQ) current and the area reduction (AR) after the RHQ process are studied. The studies have shown that the optimum RHQ current to obtain high [J.sub.c] is the current at the higher edge of the plateau region and the AR process has affected the transformation process that has determined the quality of the A-15 phase.

The feasibility study of Cu stabilized [Nb.sub.3]Al Rutherford cable for application to high field accelerator is discussed. Results suggest that the [Nb.sub.3]Al Rutherford cable possesses stronger strain-stress characteristics and is useful for application in case of compressive force beyond 150 MPa.

The study presents an analysis of the superconducting properties of [Mg.sub.2]Cu-doped [MgB.sub.2] wires with several metal sheaths. These wires come cheap, in addition to providing high critical temperature and hence can be used for various fusion reactor applications.

The synthesis of new [Nb.sub.3]Al wires with high critical current density and improved fabrication parameters, such as the heat reduction ration is being discussed. The wires exhibit conducting properties and hence can be widely used for future accelerator magnets.

The study describes the characteristics of the round and extracted strands of [Nb.sub.3]Al wires Rutherford cable with copper stabilizer, which exhibits very low packing factor. The strands can be used as future high field accelerator magnets due to the great fluctuation in their magnetization.

The analysis describes the fundamental relationship between the BCC (body-centered cubic)-deformation, the transition temperature and the microstructure of the [Nb.sub.3]Al wires. The results prove that the transformation temperature has a tendency of monotonic decrease along with the deformation.

The fabrication and operation of a rapid-heating, quenching and transformation (RHQT) [Nb.sub.3]Al insert coil generating 4.5 T at 4.2 K in 15 T back-up field are discussed. These coils are widely used as high-field magnets.

The study describes the optimization of the [(Nb, Ta).sub.3]Sn wires, which are fabricated using the Sn-Ta sheet by jelly roll processing. It is found that a small amount of Ti and Cu addition in the wires decreases the amount of Ta in the sheet considerably.

Several experiments are conducted to study the different superconducting properties of the V-Ti alloys at different conditions. The alloys are highly ductile and are greatly affected by the process of [alpha]-depositions.

A study is conducted to enlarge a Nb/Al strand dimension to enhance current capacity of RHQT-Nb3Al further. Bcc phases could be formed even in the large cross-section rectangular strand by RHQ operation.

The microstructure and performance of DRHQ processed Nb3Al tape with internal Ag stabilizers are investigated. The results support that the staking faults should be dominant as the effective pinning center for DRHQ processed Nb3Al conductors.

Structure and high-field performance of (Nb,Ta)(sub 3)Sn conductors fabricated by using ductile Sn-Ta matrix is discussed. Another process for fabricating multifilamentary-type (Nb, Ta)(sub 3)Sn conductors using ductile Sn-Ta/Nb composite is studied.

An experiment is conducted to determine the critical current I(sub c) and n-values of (rapidly heating and quenching treatment) RHQT processed Nb3Al conductors at 4.2K in a wide range fields from 14.5 to 25T in relation to the microstructures obtained. The results indicate that the n-value increased monotonously with decreasing field from 25T to 18T, but got saturated to be around 35 at 4.2K in field less than 18T.

A study is conducted to develop Nb3Ga wires by using RHQ (rapidly heating and quenching) treatment which show T(sub c) = 29.7 K and B(sub c2) (4.2K) =32 T. TEM observations clarified that the composition of Nb(sub 3)Ga varies from near-stoichiometry nearby the Nb(sub 5)Ga(sub 3) phase to Ga-poor composition nearby the Nb-Ga bcc phase.

Describing a long length of RHQ operation that is done over 300m, a transformation annealing conditions that is suitable for a coil and the resultant transport properties of the long length of conductor and coils is reported. It indicates that a long-length of the RHQ processing over 300 m and subsequent Cu-cladding is uniformly performed so that a long-length of RHQT JRNb3Al conductor gets trustworthy for practical coil applications.

Reporting a new fabrication technique for Nb/Al-Ge precursor wires, using gas-atomized Al-Ge alloy powders is discussed. It is concluded that the XRD analysis, Nb-Al-Ge ternary supersaturated bcc phase is formed with A15 and Nb5(Al,Ge)3 phases in the tape specimens with 0.2 mm in thickness, when the tape specimens are RHQ-treated.

Describing the mechanism of the thick (Nb,Ta)3Sn layer synthesis, a simplified Ta-Sn powder core process, and a new Jelly Roll (JR) process using Sn-Ta sheet richer in Sn is investigated. The JR wires show attractive high-field performance at 22-23 T, and 5wt%Cu addition tot eh sheet effectively reduces the optimum heat treatment temperature.

Investigating the microchemical and microstructural comparison high performance Nb3Al composites is discussed. In the final strands the variations is much less but longitudinal cross-sections revealed the residual chemical inhomogeneity extending along the strand length.

Discussing the superconducting properties and the microstructures of RHQ-processed Nb3Al wires with Cu addition fabricated by these alternative conditions is reported. This indicates a promising possibility of improvement of J(sub c) through the optimization of precursor wire configurations and RHQ-conditions.

Investigating the Cu added jelly -roll (JR) Nb/Al wire with various Nb/Al layer thickness and compositions and discussing their effect on RHQ process is presented. The cu added JR wire of Al poor composition for Nb3Al stoichiometry showed a behavior similar to the binary is concluded.

Fabrication of jelly-roll (JR) Nb[subscript3]Al superconductors is reported. A comparison is made involving Cu-added JR Nb[subscript 3]Al, Cu-added rod-in-tube (RIT) Nb[subscript 3]Al and ordinary rapid-heating, quenching, and transformation (RHQT) JR Nb[subscript 3]Al superconductors.

Superconducting properties obtained during an optimization study of rapid-heat processing of jelly-roll (JR) Nb[subscript 3]Al multifilamentary wires are reported and discussed.

Stress and strain tolerance is investigated for jelly roll (JR)-processed rapid-heating, quenching and transformation annealing (RHQT) Nb[subscript 3]Al superconductors. Results are enumerated and discussed.

Rapidly heating/quenching processes were used to determine stabilization and coil performance of Nb2A1 conductors.

A Ta-Sn powder core and Nb-Ta alloy sheath were used to fabricate new (Nb,Ta)3Sn high-field conductors.

Transformed jelly-roll Nb3A1 multifilamentary wires were studied to determine their superconducting properties and rapid heating condition.

A study investigated the cause of critical current density improvement in fabricated Nb3Sn superconductors with different bronze matrices by enhancing Sn content in the matrix. Two conductors were fabricated and the dependence of n-value on magnetic field in these conductors, one of which contained 15% Sn bronze and the other, 13% Sn bronze, was also examined. Experimental materials, methodology, findings and conclusions are discussed.

A rapid-heat, quench and transformation (RHQT) process was developed for fabricating Nb3Al multifilamentary wires which are 2-5 times larger than commercially available Nb3Sn multifilamentary superconducting wires. The effects of Mg and Ge additions to the RHQT-processed Nb3Al multifilamentary wire were then studied. Reduced T(sub c) resulted from the addition of Mg to the Nb3Al multifilamentary wire but had no apparent influence on H(sub c2) of 25-27 T. The Ge addition, on the other hand, increased both T(sub c) and H(sub c2).

An improved fabrication process where the wire diameter can be increased from 0.5 to 1.25 mm and the Nb-matrix ratio decreased from 1.5 to 0.52 without degrading the critical current density of Nb3Al phase was developed to enhance the current carrying capacity. To investigate the feasibility for large-scale applications, the compacted-strand-cables were fabricated. The results showed that flat-rolling and stranding the as-quenched Nb/Nb(Al)ss composite caused no degradation in J(sub c.).