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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.

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.

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.

Investigating the fabrication of Nb3Ga wire through a combination of Nb/NbGa3 composite precursor wire and RHQ treatment is discussed. It is concluded that the superconducting properties of the RHQ-processed Nb3Ga wire is improved significantly with post-annealing at 600-800 degree centigrade.

Investigating the rod-in-tube technique developed for the fabrication of Nb3Sn precursor wire for RHQ treatment is discussed. It is concluded that the addition of Bi seems not to negatively influence the superconducting the properties of Nb3Sn.

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.

Having investigating the extended E-J characteristics in an YBCO coated IBAD tapes are presented. It is concluded that the LTSLM is a powerful tool to study the local superconducting properties in YBCO coated tapes.

Having investigating the MOD methods as a low cost process for making long tapes of the YBCO coated conductors is discussed. The Results indicate that the CeO2 (100) buffered IBAD tapes are useful for TFA-MOD fabrication of long YBCO coated conductors.

Shock compression experiments on Kinosaki basalt were carried out in the interest of studying collisional phenomena in the solar nebula. Shock waves of 7 and 31 GPa were generated using a thin flyer plate, and a shock wave of 16 GPa was generated using a thick cylindrical projectile. By employing in-material manganin and carbon pressure gauges, the shock wave attenuation was examined and the propagation velocities of the shock wave and rarefaction wave were measured. The attenuation mechanism consists of two effects: the rarefaction wave and geometrical expansion. The rarefaction effect includes the reflected wave and the edge wave. The efficiency of these mechanisms depends on the geometry of the projectile, initially induced pressure, and materials of the target and projectile. As a result of the experiments, a cylindrical impactor created an isobaric region of size almost equal to the projectile radius. The shock wave in the far field was attenuated similarly with the power of-1.7 to -1.8 of the propagation distance under our experimental conditions. The shock wave generated using a thin flyer plate was attenuated by the rarefaction wave generated on the back surface of the flyer plate and by geometrical expansion effects. The shock wave generated using a thick projectile was attenuated by edge-wave and by geometrical expansion effects. According to elastic theory, the rigidity of basalt at 7 and 31 GPa was calculated as 35 [+ or -] 7 and 0 [+ or -] 3 GPa, respectively, using the measured rarefaction wave velocities. The decayed shock pressure was related to the ejection velocity of the impact fragments, which were obtained in previous disruption experiments. The attenuation rates in previous experiments were consistent with ours. The previous impact scaling parameter called 'nondimensional impact stress (PI)' has been improved. Key Words: cratering; planetary formation; impact processes; planetesimals.

Three processes are proposed for improving the superconducting properties of RHQT-processed Nb[subscript 3]Al wires. The new processes are described and compared.

The rapidly-heating/quenching process was used to make Nb3(A1,Ge) multifilamentary wires.

The Double rapidly-heating/quenching process was used to fabricate Nb3A1 conductors.

Field emission transmission electron microscopy was used to study microstructures of rapidly-heated/quenched and transformed Nb3A1 multifilamentary wires.

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.).