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The first cryogen-free 23 T hybrid magnets, consisting of an outer wide bore cryogen-free superconducting magnet and an inner water-cooled resistive magnet are constructed. The wide bore cryogen-free superconducting magnet is investigated to generate a central field of 6.0 T in a 360 mm room temperature bore.

A cryo-cooled large magnetic field gradient superconducting magnet as the insert magnet for a large bore cryo-cooled superconducting magnet is developed in order in order to study magnetic levitation. The findings indicate that this cryo-cooled magnet system quenched from the insert magnet, but could achieve nearly 1050 T(sub 2)/m.

Progress is reported involving construction of a cryogenfree hybrid magnet at the High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University, in Japan.

A cryogen-free 23 T hybrid magnet is described. The device is being built at the High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University, Sendai, Japan.

Bi(Pb)223 bulks were prepared using magnetic melt processing and oriented crystal growth was observed.

A large scale Bitter magnet was built and applied to crystal growth in levitating water.

The High Field Laboratory for Superconducting Materials at Tohoku University is discussed with regard to the development of hybrid magnets.

Nb3Sn wires with CuNb reinforcing stabilizer cooled by refrigerator were investigated for future design of cryocooled superconducting magnets.

The use of a capacitor bank of 60 kJ energy as a power supply in the development of a Bitter type magnet with three layer structure.

The use of Bi-system high temperature superconducting current leads to realize a cryogenfree superconducting magnet is described.

A 10 T cryocooled large-bore superconducting magnet has been built with (Nb,Ti)3Sn wires with CuNb composite stabilizer. The wires have an outer diameter of 1 mm, a filament diameter of 4 micrometer and 7849 filament strands. The react and wind and a tension-winding method were used in constructing the magnet. This procedure enabled the use of a coil formation technique that does not employ a large-scale heat treatment furnace or of vacuum epoxy-impregnation equipment.

High field heat treatment equipment in an 11 T cryocooled superconducting magnet is used in the melt textured process in high magnetic fields when synthesizing YBa2Cu3O7 bulk samples. The texture in grain of the YBa2Cu3O7 matrix was found by the X-ray rocking curves of (005) and (006) to have improved through an application of a magnetic field of only a few tesla. It was also found that the application of a magnetic field of ... 10 T altered the distribution of Y2BaCuOx particles.

A compact superconducting magnet was developed for a 40 T hybrid magnet. Highly-strengthened Nb3Sn wires were used to fabricate the magnets with epoxy-impregnated layer winding. The magnet has 4.1 tons of total coil mass and exhibits 16 T in a 420 mm inner diameter of windings. About 40% of the conventional cryostabilized magnet wound with copper-matrix wire was achieved.

Cu-Ag alloy is used for the repeating pulsed field magnets. It is found that fields up to 22 T or more will be available for this purpose instead of 16 T which is obtained with normal copper magnet used at present. This result is a big advantage for neutron diffraction experiments.

A 40 T compact hybrid magnet consisting of a 16 T outer superconducting magnet and a 24 T inner resistive magnet is conceptually designed. A highly strengthened superconducting magnet with a 360 mm room temperature bore can be made using newly developed [(Nb,Ti).sub.3]Sn wires with Cu-Nb or Cu-[Al.sub.2][O.sub.3] reinforcing stabilizer, and as a result the coil weight is outstandingly reduced by about 70 %. A poly-Bitter resistive magnet which generates 24 T in a 14 mm room temperature bore is realized consuming 8 MW power.

A study is conducted to investigate heat transfer in water by using a liquid-crystal sheet with thermochromism in a hybrid magnet. The result reveals that the temperature dependence of the magnetic susceptibility of water is responsible for the convection behavior in the gradient fields.

Thin-film magnets, composed of nanophase dispersed [Nd.sub.2][Fe.sub.14]B and [Alpha]-Fe have been synthesized by rf magnetron sputtering. With increasing [Alpha]-Fe volume fraction [V.sub.Fe], the saturation magnetization increased linearly, while the coercivity decreased. Ferromagnetic resonance measurements were made by using a high-frequency and high-field ESR apparatus, which exhibited two absorption peaks. A model calculation of the resonance field was made for a simplified hard/soft two-sublattice system to analyze these results. Estimated values of the exchange-coupling constant are in good agreement with those deduced from micromagnetic analysis of the magnetization curves. Index Terms--Exchange coupling, ferromagnetic resonance, nanocomposite magnet, thin film.

Fe-Si[O.sub.2] granular films with CPP (current perpendicular to plane) structure have been prepared in various Ar gas pressures by rf magnetron sputtering. The temperature dependence of resistivity and the tunneling magneto-resistance is studied as a function of the bias voltage applied between the electrodes of CPP structure. The peculiar behaviors have been observed such as the bias voltage dependence of the magnetoresistance ratio and the linear decrease in the resistivity with H above 1 T. Index Terms--Fe-Si[O.sub.2], granular magnetic film, tunneling magnetoresitance, CPP structure