Railway Technical Research Institute

Other

International Superconductivity Technology Center

Aisin Seiki Kabushiki Kaisha

Ken Nagashima

Masato Murakami

Naomichi Sakai

Toshiki Herai

Hiroyuki Fujimoto

Masaru Tomita

Mikio Takahashi

Hideo Mita

Hideo Misawa

Sang-Im Yoo

Katsunobu Kanda

Osami Tsukamoto

Atsuyuki Kobayashi

Takeshi Miyamoto

Kaoru Nemoto

There is provided a power lead for a superconductive magnet capable of controlling the invasion of heat to liquid helium for storing superconductive coils therein and of sufficiently feeding power to the superconductive coils. The power lead for a superconductive magnet of a superconductor magneto unit for supplying a current to the superconductive coils which are cooled at a liquid helium temperature through a radiant heat shielded section which is cooled at a liquid nitrogen temperature, wherein at least a part of sections positioned inside the radiant heat shielded section of a current lead member of the superconductive magnet comprises a high temperature oxide superconductor bulk body having a critical temperature exceeding a liquid nitrogen temperature. In this case, it is preferable to apply a resin impregnation treatment to the bulk body to enforce the high temperature oxide superconductor bulk body section. If at least a part of sections other than the bulk body is formed of a braided wire, a stress caused by the relative displacement between constituents of the unit does not influence upon the bulk body, thereby reducing the risk of breakage of the unit.

Power lead for superconductive magnet

The invention is to establish means of producing easily and at low cost &ldquo;a coupled body of superconducting magnets&rdquo;, comprised of multi-pole bulk superconducting magnets lined up such that the polarities thereof alternately vary so as to cause a magnetic field gradient to occur. The magnetizing method for producing a coupled body comprised of multi-pole bulk superconducting magnets with respective polarities varying comprises the steps of coupling adjacent members for bulk superconducting magnets of a plurality of members for bulk superconducting magnets with each other in such a way as to be freely superposable, foldable, and unfoldable, superposing all the members for the bulk superconducting magnets on top of one after another, and applying a magnetizing process thereto in as superposed state, and unfolding alternately and juxtaposing the respective bulk superconducting magnets as superposed after the magnetizing process as shown in FIG.,(A) to FIG.,(D).

Magnetizing method for producing coupled body comprised of multi-pole bulk superconducting magnets with respective polarities varying

A bulk superconductor is produced by subjecting REBa.sub.2 Cu.sub.3 O.sub.y oxide to oxygen annealing after many holes have been formed in the oxide body.

Oxygen annealing process for bulk superconductors

A composite material having a plurality of sections integrated into a unitary structure and each including a bulk of a superconductive metal oxide of RE--Ba--Cu--O wherein RE represents a rare earth element, the bulk of each of the sections having pinning centers and capable of trapping a magnetic field. A first one of the sections has a superconductive current density different from that of a second one of the sections. The composite material may be produced by assembling preformed respective sections into a unitary structure or by immersing one of the sections in a solution to grow crystal of Y--Ba--Cu--O superconductive on that section, followed by trimming.

Superconductive composite materials

A cooling system includes a cold-accumulating refrigerator, and a cooling circuit. The cold-accumulating refrigerator includes a regenerator. The cooling circuit includes a main circuit, and a branched circuit. The main circuit includes a counterflow heat exchanger. The branched circuit is branched from an upstream portion of the main circuit, and joined to a downstream portion thereof, thereby reducing one of the flows of a refrigerant, flowing in a high-pressure-side passage and a low-pressure-side passage which are disposed in the counterflow heat exchanger, with respect to the other one of the flows. Moreover, the branched circuit includes a heat exchanger, and the heat exchanger is thermally brought into contact with a portion of the regenerator whose temperature is varied from a high temperature to a low temperature by another refrigerant flowing therein. Thus, the cooling efficiency of the cooling system is remarkably improved synergetically by the cooling resulting from the flow-difference in the counterflow heat exchanger, and by the extra cooling stemming from the thermal-contact at the regenerator.

Cooling system

Growing community of inventors

Tokyo, Japan

Ken Nagashima