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The purpose of this work is to obtain a cooling capacity of 200 W at 80 K under power consumption of 4 kW for a superconducting magnetic energy storage system. It was found that there existed large temperature distribution in a circumference of the regenerator. The temperature difference became larger as increasing the piston displacement. The maximum difference of temperature was 150 K. Such the inhomogeneous distribution of the regenerator temperature was caused from turbulent flow of helium gas. Then several hard copper meshes were inserted to prevent the distortion of the mesh. As the result, the difference of temperature decreased to 37 K and the high performance was obtained; the lowest temperature of 37 K and the cooling capacity of 158 W at 80 K. Conclusively %Carnot was improved up to 14%. Furthermore, when power consumption was increased to 3.8 kW and the piston displacement was 16 mm peak to peak, the higher performance was obtained; the cooling capacity of 180 W at 80 K.

The effect of Ag addition on the phase diagram, solidification conditions and fabrication of large domain YBaCuO-system has been studied. Calcined powder of composition Y1.8Ba2.4Cu3.4O9-x with 0.5 wt.% Pt and 0, 1, 5, 10, 20 and 30 wt.% Ag was prepared. The melting point of each powder was measured by differential thermal analysis (DTA). A large domain (45 mm diameter and 20 mm thick) of the Ag-doped YBaCuO-system superconductor was prepared for each composition by a seeding and unidirectional growth technique which involved controlling the furnace temperature gradient. In order to assess the quality of the crystal orientation, the distribution of trapped flux density was measured. The entire sample was magnetized uniformly and the trapped magnetic field observed to form a single dome shape.

The novel reagent (I) renders possible the conversion of aldehydes into the desired α,β-unsaturated nitriles.

YBCO superconducting tapes with good superconducting property were prepared by a continuous CVD technique on 300mm long Hastelloy with biaxially aligned YSZ buffer layer. High J c of larger than 5x10 8 A/m 2 (77K, OT) covering the full length of the tapes that included the maximum value of 5.9x109A/m2 (Ic=10.4A) were achieved. The structure of YBCO tapes with high Jc larger than 109 A/m2 have been studied using by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). The precipitates with a size of 1-3μm were observed in the SEM and TEM images of YBCO tapes, and these were characterized as the gathering of Cu-O and Y-Ba-Cu-O grains with a size of 0.1-0.5μm by the EDS analysis. An area of these second phase was estimated at 10-20%, but these grew from a part of 0.3 μm in the thickness from the bottom of YBCO layer, so the effective volume of the current path within these region were not completely blocked. Good c-axis oriented growth of YBCO layer normal to the flat surface of YSZ buffer layer was shown in the cross-sectional TEM view, in addition the intermediate layer as barium zirconate (BZO) with 15-20nm in the thickness was formed on the top of YSZ layer.

Yoroi-coil (Y-based oxide superconductor and reinforcing outer integrated coil) structure has been developed to fabricate very strong pancake coils against electromagnetic force. In Yoroi-coil structure, the outer supporting structure is effective to make a mechanically robust coil having a high current density in the case that the hoop stress must exceed the yield strength of a REBCO-coated conductor without this reinforcement. By the experiments and analysis, we pointed out that the remarkably weak delamination stress can cause the delamination of the coated conductor in coils. So that Yoroi-coil structure has advantages to delamination because it could maintain a coil shape with reinforcing materials, without impregnation. Since higher current density is required by various applications, the Yoroi-coil using austenitic stainless steel reinforcing frames and plates, has been verified by the hoop stress test with high current density. Then, high coil current density of 446 A/mm 2 was achieved by the Yoroi-coil-structured double pancake (DP) coil, with the total number of the winding turns of 574, at 4.2 K in the back-up magnetic field of 11 T. The inner and outer diameters of the DP coil were 190 and 250.1 mm, respectively. Although the hoop stress evaluated on the assumption of excluding the supporting structure exceeds 1 GPa, Yoroi-coil structure restricted the strain of coil winding ranging 0.2% to 0.3%. The stainless steel reinforcing member well supported a part of electromagnetic force in Yoroi-coil structure, even with high coil current density.

Basic quasi-static tests of superconducting magnetic bearings are carried out using YBa/sub 2/Cu/sub 3/O/sub 7-/spl alpha// (YBCO) and Nd-Fe-B permanent magnets. In the thrust type tests, two kinds of c-axis oriented YBCO bulks are used. These YBCO bulks are produced by a melt process using a seed crystal. The measured maximum repulsion pressure between the YBCO and the magnet between the YBCO and the magnet is 0.14 MPa at 77 K under the zero-magnetic-field cooling condition. This repulsion pressure, which is a top level value, enables the authors to consider the application of the superconducting magnetic bearings. The attractive forces between the YBCO and the magnet under the field cooling condition are also measured at 77 K. In the radial type tests, the force between a ring-shaped YBCO bulk and a shaft combined with multi-ring magnets are measured in the liquid nitrogen. A simplified formula is proposed to evaluate the repulsion force. As an application of the superconducting magnetic bearings, a flywheel system is preliminary designed for the energy storage of one kilowatt-hour. The flywheel, which is made of fiber reinforced plastic, is a ring shape having an outer diameter of 600 mm and a height of 100 mm. >

YBa 2 Cu3O 7-x (123) bulk superconductor, which contained uniformly dispersed fine Y2BaCuO5 (211) grains, was fabricated with pre-synthesized Y 2 BaCuO 5, BaO 2 and CuO powders by a partial melting process. The size reduction of pre-synthesized 211 powders by fine grinding and low temperature calcination had a positive effect on the homogeneous distribution of fine 211 grains in super- conductor bulk materials. The critical current density, J C , in a magnetic field increased approximately in proportion to the total surface area of 211 grains per unit weight in the 123 phase. When the magnetic field increased, the increase of J C with the increase of surface area of 211 grains became steep.

Curved bulk material is required in a radial bearing. To reduce the damage and the dust caused by curving, the bulk materials with the convex and the concave shapes of the Ag-doped SmBaCuO-system superconductors were prepared by bending the precursors in a melt process. The orientation of the bulk material was not curved although the surface was curved. The entire arch shaped bulk material had the same the orientation as the seed. The trapped magnetic field of the bulk material formed a single dome shape with the maximum trapped magnetic flux density of about 1.2 T.

We developed Bi-2223 narrow tape for a transposed segment conductor. The tape was 0.23 mm thick and 1.90 mm wide, almost half the conventional tape width. It used a Ag–Mg–Sb alloy for the sheath material and consisted of Ag/SC ratio of 2.2 and 37 filaments. We adjusted the Ag/SC ratio to improve the mechanical strength of the newly developed narrow tape and obtained a tensile strength of 108 MPa. The narrow tape kept the initial Ic value until a flat-wise bending strain was up to 0.6% or an edge-wise bending strain was up to 0.3%. Moreover, it was flexible enough to be machine-fabricated into a transposed segment conductor.

The single large domains of Ag-doped SmBaCuO-system superconductors with several compositions of Sm 1+2 x Ba 2+ x Cu 3+ x O y ( x =0, 0.1, 0.2, 0.3, 0.4) were prepared by a melt process. The sample size was 45 mm in diameter and 20 mm in thickness. The lattice parameter, the critical temperature ( T c ) and the dependence of the critical current density ( J c ) on the applied magnetic field were measured with XRD, a vibrating sample magnetometer and a SQUID magnetometer. The T c and the peak effect of the J c – H property were highest at x =0.2 in that the c -axis and the a -axis had a maximum value.

Cube-textured Ag tapes of Ag{1 0 0} 〈0 0 1〉 were investigated to obtain in-plane aligned Re123 films, where Re represents Y, Gd, Sm and Nd by a continuous chemical vapor deposition technique. Y123 and Gd123 films formed on Ag{1 0 0} 〈0 0 1〉 tapes showed two types of the location, cube-on-cube and diagonal-on-cube, because of the lattice mis-fit between Ag and Y(Gd)123. On the other hand, Nd123 and Sm123 films formed at lower deposition temperature of 760°C indicated the good in-plane texturing. The in-plane aligning defined from the ratio of the (1 0 3) peak intensities by X-ray pole figure measurement was improved to 89% for Nd(Sm)123 films compared with 50% for Y(Gd)123 films.

The strain effect on critical current (Ic(?)) in Y Ba2Cu3O7 ? ? (YBCO) coated conductors was evaluated at temperatures in the range 20?83?K under magnetic fields parallel to the c-axis up to 10?T. The peaked reversible variation of Ic with applied uniaxial strain was confirmed in the self-field at all tested temperatures. The strain sensitivity increases with increasing temperature, resulting in a more pronounced reversible suppression with strain at higher temperature. Interestingly, it was found that the peak strain corresponding to the maximum of Ic shifts to the compressive side with decreasing temperature. Such a peak shift cannot be explained by a change in the thermal residual strain of the YBCO film, suggesting that the peak strain of the Ic(?) in YBCO coated conductors is not determined only by relaxation of the residual strain. The strain sensitivity of Ic(?) at 60?K becomes greater with increasing magnetic field, while the influence of the magnetic field is much less pronounced at 20?K. The in-field Ic(?), including the compressive strain region as well as the tensile region, shows a double peak behavior at low magnetic field at 77 and 83?K. The temperature and magnetic field effect on Ic(?) in YBCO coated conductors is discussed considering flux pinning within the grains and on grain boundaries.

The Y-Ba-Cu-O thick films have been prepared by a paint-on method using the mixtures of powders and organic vehicles. The structure and Jc of the films made from three different kinds of powders were reported. The Jc value has been improved by the use of melt quenched powders. Fine particles of the 211 phase with diameters of submicron were homogeneously distributed in the 123 phase. The c-axis crystal orientation was enhanced by the addition of Ag2O to melt quenched powders. The maximum Jc value exhibited 7.5*104 A/cm2 at 77 K and 0.1 T estimated by the magnetization measurement.

New Horner–Wadsworth–Emmons reagents, ( o - t -BuPhO) 2 P(O)CH 2 CONMe(OMe) and ( o - t -BuPhO) 2 P(O)CH 2 CON(CH 2 CH 2 ) 2 O were prepared via the Arbuzov reaction in good yields. The HWE reaction of these reagents with a variety of aldehydes gave cis-α,β-unsaturated amides with high selectivity in almost quantitative yields.

Intensive research work has been carried out in order to develop industrially available HTS REBCO-coated conductors under the NEDO project in Japan. Recently, several groups in the project succeeded in the development of high performance coated conductors. Their characteristic features have been evaluated in terms of mechanical properties and their influence on critical currents. The mechanical properties at RT and 77 K were analyzed on the basis of the rule of mixtures. The force-free strain (Aff) was analytically deduced, which indicates the strain at which the residual stress exerted on the superconducting layer becomes zero. Tensile strain dependence on critical currents could be divided into elastic and brittle regions. The reversible strain limit (Arev) was defined as a strain at which the critical current recovers elastically to the level of 99% Ico. Within the elastic region, the critical current showed a convex strain dependence, which is explained as Ekin's intrinsic strain effect. The degradation beyond the reversible strain limit was attributed to a fracture of the superconducting layer. As a whole, the present study made clear quantitatively the tensile strain behavior of critical currents and proposed a reasonable definition for the reversible strain limit.

Tensile fatigue tests were carried out at 77 K for YBCO-coated conductors fabricated by metal–organic chemical vapor deposition (MOCVD). The S–N relationship, variation of critical current (Ic) during cyclic loading and microscopic fatigue damage were investigated. Fatigue strength at 106 cycles was evaluated to be σmax = 1300 MPa and 890 MPa under the stress ratios of 0.5 and 0.1. Two different mechanisms of fatigue damage, depending on the number of stress cycles to failure, were observed. In one of the fracture mechanisms, fatigue behavior is characterized by overall fracture which occurs at 104–105 cycles. For these specimens, Ic after unloading does not degrade before overall fracture. Although only shallow slip bands were found at the Ag surface, fatigue cracks were found on the Hastelloy C-276 surface of the fractured specimen. These results suggest that overall fracture due to cyclic stress was caused by fatigue of the Hastelloy substrate. In the other fracture mechanism, even though overall fracture did not occur at 106 cycles, a slight decrease of Ic was detected after 105 cycles. No fatigue crack was found on the Hastelloy surface, while deep slip bands corresponding to the initial stage of fatigue crack were observed on the Ag surface. From these results, we concluded that Ic degradation at a high cycle number is attributed to the fatigue of the Ag stabilizing layer.

The radiation-stability of annealed and quenched polyethylene (PE) was estimated by gel, FTIR, and mechanical property (elongation at break) measurements. Although both types of PE showed an equal probability in gel and carbonyl formation, the resistance to γ-ray irradiation as probed by elongation at break (%) was superior in quenched PE compared to annealed PE. This difference is discussed from the viewpoint of polymer structure, especially the number of the tie molecules, of annealed and quenched PE.

Four kinds of annealed polyethylene (PE) films with varying densities were photo-irradiated with a medium pressure mercury lamp. Photodegradation processes were followed by ultraviolet (UV) and Fourier transform infrared (FTIR) spectroscopic techniques and by gel and mechanical property measurements. Oxygenated products build-up was more favored in linear low density (LLD) PE and the rate of formation increased in the reverse order of polymer density. A similar trend was seen in gel formation. Measurements of elongation at break (%) showed that the embrittlement time of photo-irradiated PE increased with the decrease of polymer density. The experimental results on unquenched samples were compared with those of quenched samples. It was found that the density (or crystallinity) and crystal size of PE play important roles in determining photostability.

Publisher Summary This chapter describes AC loss properties of Bi-2212 multifilamentary round wires and their Rutherford-type cables, which may be one of candidates for large-capacity windings in the electrical devices such as future superconducting magnetic energy storages (SMES) and so on, from a viewpoint of feasibility study. The strands are not twisted. Their AC loss properties in a transverse magnetic field are to be like those of monofilamentary wires in spite of the multifilamentary structure. The experimental results partially support the prediction that the AC loss is hysteretic. The experiments also give unexpected results that the effective diameters of the filamentary region evaluated from the measured AC losses are much smaller than the actual ones. The AC losses obtained for the strands were scarcely dependent upon the frequency of the external field in the range from 0.02 Hz to 10 Hz. This suggests that the hysteresis loss in a tightly coupled filament bundle be dominant. A remarkable improvement in the AC loss characteristic by reducing an effective diameter of the filament bundle are observed, while twisting the filaments itself does not contribute to the reduction in the AC loss. It is also found from the comparison between the AC losses in the strands and the cables that the AC losses in the cables mainly came from the individual strands.

Liquid nitrogen is expected to be used as dielectric material in high T/sub c/ superconducting power cable systems. In an electric power apparatus such as a termination for high T/sub c/ superconducting power cable, we need to consider not only radial electric stress but also axial electric stress. A particular concern is the dielectric breakdown at the surface of solid insulator in liquid nitrogen. We evaluated the surface discharge characteristics on the surface of the solid insulator in liquid nitrogen experimentally.

Liquid nitrogen can be used as cooling medium for high-Tc superconducting cables. In order to allow liquid nitrogen to flow properly under pressure, we must consider the pressure required for electrical insulation and the pressure drop of liquid nitrogen. Pressure drop is determined by factors such as pipe shape, liquid viscosity, specific gravity, and flux. It is essential to have a good grasp of these factors in designing a cooling system.As part of preliminary study, we measured pressure drops within straight pipe and corrugated pipes. Then, we introduced a round bar into each of these pipes to determine the relationship between change in pressure drop and round bar diameter. The following makes a report on our findings.

We developed a new robust Rutherford cable using Bi-2212 high temperature superconducting (HTS) wire, which consisted of 427 superconducting filaments and which had a critical current density (Jc) value of 2.400D7;1 05A/cm2 at 4.2K in self-field. For applications requiring a Rutherford cable with a core such as NiCr, we found that a plasma sprayed ZrO2 film was most effective in preventing “poisoning” elements present in the core from diffusing into and poisoning the HTS wire. Rutherford cable made with this wire and a thin NiCr, core protected by ZrO2 film barrier layer was able to carry an Ic value of 3,570A. The Ic degradation in Bi-2212 AgMgSb sheathed wire was only 10%. Finally, we demonstrated the successful fabrication of an 80m-long Rutherford cable.

We have tackled with the improvement of the superconducting magnetic bearings and manufactured the newly developed facility which has possessed the cooling device with cryogenic refrigerator and the driving device for the completely floating rotational elements, and can be utilized to research and development for various type of the bearings. We have confirmed the small loss of 0.26W about the axial gap thrust bearing of 238mm diameter at speed of 3000 min2212;1 and load of 281N. We introduce the test facility and report the test results.

We developed Ag-Mg-Sb alloy-sheathed Bi-2223 round wire with a unique design. Jc value of the round wire was 8,000A/cm2 at 77K in self-field and had no angular dependence of backup magnetic field. The round wire had a tensile strength of 148MPa at room temperature and the Jc value remained constant up to an applied tensile stress of 140MPa. We fabricated a 1m long cable consisted with alloy-sheathed round wire and alloy round wire. The Ic value of the stranded cable was 500A at 77K in self-field.

The large single domain of Ag-doped SmBaCuO-system superconductors with several compositions of Sm1+2xBa2+xCu3+xOy (x=0, 0,1, 0.2, 0.3 and 0.4) were prepared by a melt process. The sample size was 45mm in diameter and 20mm in thickness. The dependence of the critical current density (Jc) for applied magnetic field was measured by a SQUID. The axial component of the trapped magnetic flux density was measured by scanning a Hall element sensor. Ttie remarkable peak effect was observed in the range of x=0.1 to 0.2. The maximum trapped magnetic flux density was highest at x=0.2, then it was 1.3T

Good c-axis oriented YBCO films were formed directly on both non-textured and cube- textured Ag tapes. 11m long YBCO tape with Jc (lμV/cm) of 3.0x104A/cm2 at 77K, 0T was prepared on roll milled non-textured Ag tape at a forming rate of 3.0m/h. YBCO films formed on cube-textured Ag{100} tapes showed two types of the location, cube-on-cube and diagonal- on-cube between YBCO and Ag, however, no inter-diffusion between YBCO and Ag was analyzed by TEM-EDS study, and also the epitaxial growth of YBCO layer grew on Ag{l00} was observed.

We have succeeded in preparing large c-axis oriented single-grained Y-system and Sm-system superconductors by the melt process in air. The grain growth was improved by adding Ag in the systems. In this study, the melt process was applied for preparing single-grained Eu-system and Gd-system. Calcined powder of compositions of RE1.8Ba2.4Cu3.408.5 (RE=Eu, Gd) with a Pt powder of 0.5 wt% was prepared. Ag was added into the calcined powder with content of 10 and 20 wt%, respectively. The crystallized temperature of them was determined by the liquidus temperature measured with TG-DTA. A single-grain of Ag-added Eu-system and Gd-system superconductors with a 45 mm diameter and a thickness of 20 mm were prepared by seeding and using the unidirectional growth technique by controlling the temperature gradient in the furnace. The relationship between the distribution of trapped magnetic flux density and Jc for the RE (RE=Sm, Eu and Gd)-system superconductors presented.

The mechanical property of YBCO superconducting tapes was studied. A number of micro-cracks were observed clearly at bi-axially aligned tape, in the both YBCO and YSZ layer perpendicularly to the longitudinal direction of the tape. On the other hand, several cracks that connect through the gaps were observed indistinctly at mono-axially aligned tape, in YBCO layer. From this work, it was clear high Ic and good flexibility were maintained until 1.0% at bending YBCO tapes compressive.

The effect of the deposition conditions (Po2 Ts) on the crystallinity of YBCO films was investigated. The stability line estimated in this work shifted to higher Po2 region compared with the equilibrium phase diagram of Y-Ba-Cu-O system, because of O2 gas used up not only for the crystallization of YBCO but also for the thermal decomposition of the organic matter added to the precursor. The improvement of the formation rate of YBCO tape was investigated by employing a highly concentrated THF single solution of mixed s-diketonates. Good superconducting properties were achieved on STO(100) at a moving rate of the substrate from 0.5 to 3.0m/h by using the THF solution of 10.7wt%. YBCO tapes with Jc of 2.1×105 and 1.6×105A/cm2 (77K, OT) were also obtained at 0.2 and 1.0m/h, respectively, by using Hastelloy tapes with biaxially aligned YSZ buffer layer.

We developed the numerical analysis of magnetic force characteristics in high-Tc bulk superconducter. In analysis using the measured Jc, We obtained good agreements with experimental results under different magnet diameter condition. The results show that we obtained anticipation method of magnetic force characteristics of high Tc superconducting bearing. Moreover we evaluated the magnetic force of 1kWhr superconducting flywheel system which arranged plural circular superconductors. It was confirmed good agreement with experimental results. So we will be able to evaluate the magnetic force characteristics of flywheel system without many experimental examinations.

The effect of Ag addition on the phase diagram, solidification conditions, and fabrication of large domain YBaCuO-system has been studied. In this study, the compositions of REi.8Ba2.4Cu3.4Oy(RE=Y,Sm) with a Pt powder of 0.5 wt% and various amounts of Ag powder were prepared and the melting temperatures were measured by a TG-DTA, respectively. Considering these results, a large domain of an Ag-doped Y-system and Sm-system superconductor with a 45 mm diameter and a thickness of 20 mm was prepared in air by seeding and using the unidirectional growth technique by controlling the temperature gradient in the furnace.

We investigated effect of the surface conditions to the a. c. losses of layered conductor consisted of Ag-sheathed Bi-2223 tapes. The tapes were produced by the powder-in-tube method. These tapes were treated to be different layer conditions, the a. c. losses under self-field were measured by the a. c. transport measurement method. First, we investigated the influence of surface resistance by using non treatment tapes, resistive metal coated tapes, hastelloy sheet between tapes, and insulator between tapes. In the case of resistive metal coated tapes, the resistance between the tapes were 5.4 X lO-1 Ωcm2 (77K) and then a. c. loss was same as the value of insulator between tapes. Second, we investigated the difference of parallel segment and transposed segment. In the case of transposed segment, the a. c. loss was reduced to about 75% of parallel segments.

We report on a novel melt process for synthesizing YBCO superconductors which makes full use of the sensitive dependence of the melting point on the oxygen partial pressure. The solidification process of the partially molten oxide was successfully controlled only by changing oxygen partial pressure under a given temperature gradient along the furnace. This method was capable of dispersing uniformly Y2BaCuO5 (Y211) particles with submicron size. The YBCO superconductors synthesized by this technique exhibit a peak in the field dependence of Jc. The peak in the Jc-B curve is found to be caused by the two-step annealing, particularly first annealing at 600°C in oxygen atmosphere.

A large single domain of the Ag-doped YBaCuO-system superconductor was prepared. To estimate the effect of the Ag adding, the Jc and the trapped magnetic field were measured. The entire sample was uniformly magnetized and the trapped magnetic field formed a single dome shape. The Jc value decreased with the increase of the Ag content. The decrease rate of the Jc value was calculated by assuming that the Ag was not effective in the flux pinning. The calculated decrease rate is approximately equal to the experimental results.

A full-scale CFRP flywheel for 1kWh superconducting flywheel system with the outer diameter of 600mm was manufactured, and it has been confirmed that the rotor was able to rotate having the margine of the speed of 1.35 times to designed rotating speed, 20000rpm. A multi-layered construction supporting with the partial spherical membrane-type structure rigidly fixed to the rotor was used.

A 40 MWh hybrid power storage system with Superconducting Flywheel and a high-temperature Superconducting Magnet Energy Storage system (HTc-SMES) is proposed. A Flywheel is used for a base load with power of 10 MW during four hours, and SMES is used for instantaneous power of 10 MW during one second. The principal characteristic of this hybrid power storage system is that a single power conditioning system can be commonly used.

The cooling-span length design of the high-Tc superconducting cable system applied with liquid-nitrogen flow must be investigated to determine whether its use is practical. The liquid-nitrogen flow system design involves many difficulties due to its low friction factor. To investigate the pressure drop of liquid-nitrogen flow in the conductor conduits of real-scale cables, not only the straight conduit but also the corrugated conduit are providing a straight portion of 25 m. Comparison of the experimental results for each conduit pressure drop shows that the friction factor of the corrugated conduit is larger than the design value if the Reynolds number is kept constant. Thus, the result, should be applied in the design of a high-Tc super-conducting system.

The highly concentrated THF single solution of mixed CVD precursors was prepared as one of the simple method to improve the formation rate of YBCO tape. YBCO films deposited on STO(100) single crystalline substrates by using the concentrated THF solution of 10.7wt% maintained good properties at a moving rate of the substrate from 0.50 to 3.0m/h. YBCO tape formed at l.0m/h on 11cm long Hastelloy tape with biaxially aligned YSZ buffer layer showed Jc of 1.6x105A/cm2 through the total length at 77K, 0T, which was as high as one formed at 0.20m/h by using the THF solution of 2.90wt%. Forming double-layers of YBCO was studied by using the single-reactor to simulate the multi-layers by a multi-reactor. Two times as thick as the single-formed YBCO films was obtained in the double-formed films, and the similar Jc values were achieved in both films on STO(100). The low resistive joining of YBCO tapes was also studied, and the resistance value at the interface between Ag and YBCO layer was more than two orders of magnitude larger than ones at Ag and solder layer, when the wrapped area at the joint was 0.5x1cm2

Publisher Summary This chapter focuses on a method which can simultaneously estimate both the resistivity (ρ) and the magnetic penetration depth (λ) by vertically measuring the difference in the impedance between two circular solenoid coils; one with and the other without a rod-shaped sample conductor. It is easy to measure the frequency dependence of ρ and λ. On evaluating the property of superconductors, the critical current density (Jc) is taken as one of the most important properties except the temperature properties of ρ and λ. In order to estimate Jc, AC method is commonly used. In this method λ is estimated when the AC magnetic field (b) is supplied for the specimen, and Jc is calculated from the inclination between b and λ under DC magnetic field. For the SRPM method, Jc has been obtained by using the same analysis. The values of Jc obtained from the both methods are compared.