Sumitomo Electric Industries, Limited

Shinichi Kobayashi

Takeshi Kato

Tetsuyuki Kaneko

Ryosuke Hata

Naoki Ayai

Kengo Ohkura

Jun Fujikami

Kouhei Yamazaki

Noritsugu Hamada

The invention offers a superconducting coil that has the shape of a pancake formed by winding a superconducting conductor. The superconducting conductor is composed of a tape-shaped (Bi, Pb)2223-based superconducting wire and a tape-shaped thin-film RE123-based superconducting wire that are electrically connected in parallel with each other. The coil generates only a low voltage in the steady-operation state, limits the generated voltage to a low level even in a state where an external disturbance enters for some reason, and is therefore less susceptible to quenching. Consequently, the coil can be operated stably in both states. The invention also offers a superconducting conductor to be used to form the coil.

Superconducting coil and superconducting conductor for use therein

A low-cost superconducting coil which can generate a high magnetic field at comparatively high temperature is provided. The superconducting coil is formed in a pancake shape by winding a superconducting conductor that is made by electrically connecting a tape-shaped (Bi,Pb)2223 superconducting wire and a tape-shaped RE123 superconducting wire in series such that the tape-shaped (Bi,Pb)2223 superconducting wire is arranged in the outer circumferential part and the tape-shaped RE123 superconducting wire is arranged in the internal circumferential part.

Superconducting coil and superconductor used for the same

An apparatus inspecting a superconducting wire includes: a blue LED emitting light in a direction normal to a front surface of a superconducting wire to illuminate the front surface; a red LED emitting light in a direction forming an angle with the direction normal to the front surface of the superconducting wire to illuminate the front surface; a color line sensor mainly receiving light reflected by the superconducting wire, and mainly receiving light diffused by the superconducting wire; and a computer accumulating and outputting a quantity of light received by the color line sensor. The apparatus can inspect with high sensitivity whether the superconducting wire has a defect or not.

Superconducting wire inspection apparatus and method

The method of preparing an oxide superconducting wire comprises steps of preparing a wire by coating raw material powder for a Bi&mdash;Pb&mdash;Sr&mdash;Ca&mdash;Cu&mdash;O based oxide superconductor including a 2223 phase with a metal and heat treating the wire in a pressurized atmosphere containing oxygen in a prescribed partial pressure, and the total pressure of the pressurized atmosphere is at least 0.5 MPa. The pressure heat treatment apparatus comprises a pressure furnace storing and heat treating a target in a pressurized atmosphere, a pressure regulator for measuring the total pressure in the pressure furnace, an oxygen concentration meter for measuring the oxygen concentration in the pressure furnace and a controller for controlling the oxygen partial pressure in the pressure furnace in response to the total pressure measured by the pressure regulator and the oxygen concentration measured by the oxygen concentration meter.

Pressure heat treatment apparatus employed for preparing oxide superconducting wire

Method of preparing oxide superconducting wire and pressure heat treatment apparatus employed for the method

Manufacturing process of superconducting wire and retainer for heat treatment

The diameter of a first metal tube charged with raw material powder is reduced for obtaining an elementary wire. A plurality of such elementary wires are charged into a second metal tube, which in turn is reduced in diameter for obtaining a round first wire having a plurality of first filaments. The first wire is uniaxially compressed thereby obtaining a tape-like second wire having a plurality of second filaments. The second wire is heat treated thereby obtaining an oxide superconducting wire including a plurality of superconductor filaments. The maximum grain size of the raw material powder is smaller than the minor diameter of the first or second filaments.

Growing community of inventors

Osaka, Japan

Shinichi Kobayashi