Hitachi, Ltd.

Hitachi Engineering Co., Ltd.

Hitachi Engineering Services Co., Ltd.

Hitachi Engineerings and Services Co I, Ltd.

Teruhiro Takizawa

Tadasi Sonobe

Ken Yoshioka

Masayuki Shibata

Hideshi Fukumoto

Fumio Suzuki

Naoki Maki

Toshio Saitoh

Yoko Kameoka

Takashi Kobayashi

Norihide Saho

Hiroyuki Watanabe

Susumu Harada

Takao Funamoto

Takeo Nemoto

Naofumi Tada

Hisanao Ogata

Fumio Iida

Masahiko Sakamoto

Takashi Haramaki

Tomoo Chiba

Miki Yamazaki

Kazuo Kuroishi

Mituo Nakamura

Jun Kawamura

Fumihiko Goto

Shigeru Sakamoto

Naoki Kasahara

Kozo Matsumoto

Takeshi Yamagiwa

Shizuo Tsujimoto

A superconducting magnet includes: first and second torus coolant containers substantially symmetrically, vertically arranged to have a space and a symmetrical plane therebetween for storing a coolant. Each of the first and second torus coolant containers includes therein a main coil bobbin with a main coil for generating a measurement magnetic field, a shield coil bobbin with a shield coil for generating a shielding magnetic field for suppressing outside leak of the measurement magnetic field, a plate member vertically reinforced at a plane thereof opposite to a plane thereof facing the symmetrical plane for supporting the shield coil bobbin and the main coil bobbin. The main coil bobbin is further supported by the shield coil bobbin, to cause the main coil to generate the measurement magnetic field having a substantially uniform magnetic field intensity at a middle region of the space. A magnetic resonance imaging apparatus using the superconducting magnet is also disclosed.

Superconducting magnet and magnetic resonance imaging apparatus using the same

A superconducting magnet abnormality detection and protection apparatus is for early and surely detecting abnormality in superconducting coils mounted on a vehicle and protecting the superconducting coils. Magnetic flux detecting devices are mounted inside an outer vessel, which is a vacuum container of a superconducting magnet, so as to be opposite to the superconducting coil. Voltages induced in the magnetic flux detecting devices are detected. Voltage signals are led to a decision device. By monitoring the change of the voltage signals with time in a comparing judgment device, it is determined whether there is an abnormality. If there is an abnormality, an alarm indicator informs of an abnormal state, and a protection device takes protection measures such as interruption of the current of the superconducting magnet. Owing to such configuration, heat does not penetrate from the outside into the superconducting coil via instrumentation lead wires of the magnetic flux detecting devices. Magnitudes of vibration and displacement of the superconducting coil can be detected without contacting the superconducting coil. By always monitoring these signals, it becomes possible to early detect an abnormality in the superconducting coil and protect it.

Superconducting magnet abnormality detection and protection apparatus

A beam member which is installed at diametral portion in a ring shape superconducting coil container for supporting hoop stress of the coil, or a portion of radiant heat shield covering the beam member, is partly or entirely composed of electrical insulators or high resistivity materials. In accordance with the above composition, eddy current which is generated in the coil container when the superconducting coil container crosses magnetic field caused by eddy current which is generated in the radiant heat shield when the radiant heat shield crosses strong magnetic field caused by the superconducting coils with relative vibration of the radiant heat shield to the superconducting coil by a dynamic cause can be suppressed. Accordingly, heat generation in the superconducting coil container can be reduced, and consequently, generation of quenching can be prevented.

Superconducting magnet

There is disclosed a coil structure which can be rapidly energized or excited, and which reduces the generation of heat in a coil container by an eddy current due to a dynamic disturbance such as vibration and a magnetic field fluctuation, thereby suppressing the occurrence a quench. The coil container is constituted by a low-resistivity material, and a high-resistivity portion is provided at at least one portion of the coil container in the direction of the periphery of the coil container. The high-resistivity portion is provided at a position where a vibration displacement is small or a magnetic field fluctuation is small. When the coil structure is to be energized or excited, the eddy current produced in the direction of the periphery of the superconducting-coil container can be reduced at the high-resistivity portion, and when the dynamic disturbance develops, the generation of heat by the eddy current is suppressed by the low-resistivity material.

Coil structure and coil container

A superconducting magnetic field generating apparatus, and coil, a superconducting wire, a method of producing a coil and a method of connecting a superconducting wire which are suitable for such a superconducting magnetic field generating apparatus are disclosed. The superconducting magnetic field generating apparatus has a coil of a wound superconducting wire which is composed of superconducting wires with the end portions thereof connected with each other. Each of the superconducting wires is composed of a plurality of superconducting material wires embedded in a stabilizing member. The group of superconducting material wires is embedded at the connecting portion in a state in which the superconducting material wires are densely gathered to the central portion of the stabilizing member and the superconducting material wires are directly in contact with each other. The stabilizing member exists in the central portion of the assembly of the superconducting material wires and the stabilizing members are closely bonded to the superconducting material wires.

Superconducting magnetic field generating apparatus and method of

A levitation system of a magnetically levitated train is provided wherein superconducting magnets are installed in a car body, and the first layer and the second layer of levitation coils are so arranged as to be in a shifted location relative to each other in the moving direction of the train. By making the levitation coils two layers and by arranging the two layers in the shifted location relative to each other in the moving direction, amplitude of higher harmonic waves is reduced to a very small level, substantially to zero.

Levitation system of a magnetically levitated train

A refrigerator having a pressurizing device, a coldness generating device for generating coldness by expanding a portion of operating fluid which has been pressurized by the pressurizing device and a fluid passage through which the operating fluid is, via a device to be cooled, again circulated to the pressurizing device after the residual portion of the operating fluid has been cooled by the coldness generating device. A regenerator type heat exchanger is disposed in the fluid passage through which the operating fluid passes, and a switch device switches the flow of the operating fluid in the fluid passage to the reverse direction at a predetermined time period.

Gas swing type refrigerator

In a superconducting magnet apparatus including one winding of coiled superconductor wire, another winding of coiled superconductor wire, a cooling device for supplying coolant to cooling vessels which contain the respective windings therein and a non-magnetic partition wall interposed between the cooling vessels containing the respective windings to airtightly separate them, with these windings being located at relative positions enabling mutual inductance therebetween, even if quenching occurs in the superconducting magnet apparatus. It is designed to not lose the magnetic repulsive force such that equipment traveling at high speed can be safely transferred at least to the nearest station. In addition, electromagnetic levitation traveling equipment on which the above-described apparatus is installed and a control method therefore is also described.

Superconducting magnet apparatus, cooling system therefor, and

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Hitachi, Japan

Teruhiro Takizawa