Hitachi, Ltd.

Hitachi Medical Corporation

Other

Hitachi Engineering Co., Ltd.

Sh Copper Products Co., Ltd.

Hitachi Cable, Inc.

National Research Institute for Metals

Yoshihide Wadayama

Hirotaka Takeshima

Kenji Sakakibara

Hiroyuki Watanabe

Akira Kurome

Takao Honmei

Shigeru Kakugawa

Tsutomu Yamamoto

Takeshi Yatsuo

Tsuyoshi Wakuda

Katsuzo Aihara

Kazuhiko Nakagawa

Morio Kimura

Kunihito Suzuki

Hirofumi Motoshiromizu

Michiya Okada

Tomoichi Kamo

Toshihide Nabatame

Ushio Kawabe

Takahiko Kato

Kazumasa Takagi

Toshikazu Nishino

Shinpei Matsuda

Yutaka Misawa

Toyotaka Yuasa

Tokuumi Fukazawa

Yukio Saito

Katsunori Azuma

Haruhiro Hasegawa

Katsuki Miyauchi

Jiro Kuniya

Katsumi Ohata

Toshimi Matsumoto

Kiyoshi Inoue

Shin Hoshino

Masahiro Ogihara

Kunihiro Takayama

Naohumi Tada

Kunihisa Kamata

Ryou Nishiwaki

A precursor for a NbSn superconductor wire to be manufactured by the internal diffusion method, includes a plurality of Nb-based single core wires, each of which includes a Nb-based core coated with a Cu-based coating including a Cu-based matrix, a plurality of Sn-based single core wires, each of which includes a Sn-based core coated with a Cu-based coating including a Cu-based matrix; and a cylindrical diffusion barrier including Ta or Nb, in which the plurality of Nb-based single core wires and the plurality of Sn-based single core wires are regularly disposed, wherein the plurality of Nb-based single core wires include Nb-based single core wires having a Cu/Nb ratio of 0.4 or more, wherein the Cu/Nb ratio is a cross sectional area ratio of the Cu-based coating to the Nb-based core.

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A precursor for a NbSn superconductor wire to be manufactured by the internal diffusion method. The precursor includes Nb-based single core wires, Sn-based single core wires, and a cylindrical diffusion barrier made of Ta or Nb. Each Nb-based single core wire includes a Nb-based core coated with a Cu-based coating made of a Cu-based matrix. Each Sn-based single core wire includes a Sn-based core coated with a Cu-based coating made of a Cu-based matrix. The Nb-based single core wires and the Sn-based single core wires are regularly disposed in the diffusion barrier. The Nb-based single core wires includes at least two kinds of Nb-based single core wires having different Cu/Nb ratios and the Cu/Nb ratio is a cross sectional area ratio of the Cu-based coating to the Nb-based core.

A magnetic resonance imaging apparatus is provided in which vibration of a gradient magnetic field coil is reduced, the vibration is not transmitted to a static magnetic field correcting unit, and space can be saved.

Magnetic resonance imaging apparatus

Structure for reducing noise in magnetic resonance imaging apparatus

An MRI apparatus having a configuration that reduces vibration of a static magnetic field generating source is provided. A closed vesselof the static magnetic field generating source is provided with a rigid structurefor preventing transmission of vibration generated from a gradient magnetic field generating partto other members via the closed vessel. The rigid structureuses, for example, a connecting partthat connects a faceon the imaging space side and a faceconfronting it. The rigidity of the closed vessel is thereby increased, and therefore vibration transmitted from the gradient magnetic field generating part can be reduced. The connecting part can have a through-hole structure, and in such a case, internal space of through-hole can be used for drawing cables.

Magnetic resonance imaging device

In the MRI apparatus of the present invention, a reinforcing member is firmly provided so as to enhance the rigidity strength of two connecting tubes connecting upper and lower cryostats, thereby suppression of vibration caused by a gradient magnetic field coil and suppression of variation of static magnetic field can be realized. Further, in the MRI apparatus of the present invention, the reinforcing member is provided in upper and lower portions of the connecting tubes of the vacuum vessels, thereby suppression of vibration caused by the gradient magnetic field coil and suppression of variation of static magnetic field can be realized. Further, in the MRI apparatus of the present invention, the reinforcing member is provided in upper and lower parts of the vacuum vessels, thereby suppression of vibration caused by the gradient magnetic field coil and suppression of variation of static magnetic field can be realized.

Magnetic resonance imaging apparatus with suppressed noise

The present invention is intended to provide a magnetic pole, a magnet apparatus, and a magnetic resonance imaging apparatus that the magnetic structure of the magnet apparatus for generating a uniform magnetic field is formed in a lower burst mode, and the profitability is increased, and at the same time, the uniformity of the magnetic field is improved. According to the present invention, the magnetic poles arranged opposite to each other across a measuring space have at least one of a plurality of hollows and a single hollow having a shape continuously changing on the section perpendicular to the direction of the magnetic field formed in the measuring space and particularly in order to make the magnetic field uniform, the arrangement of the plurality of hollows and the shape of the single hollow are adjusted. The magnet apparatus and magnetic resonance imaging apparatus of the present invention are structured as mentioned above.

Magnetic pole magnet device using the magnetic pole, and magnetic resonance imaging apparatus

A magnet device provided with a shield current carrying means in which two sets of magneto-static field generating sources for generating magnetic fields directed towards a first direction are disposed facing each other across a finite region and at least one set of the magneto-static field generating sources are disclosed on at least two almost concentric circles. A first plane includes a first axis, a second axis and a first point. The first point is a point of insertion between the first axis parallel to the first direction and passing almost through the center of the shield current carrying means. The second axis crosses at right angles to the first axis and is spaced almost equal distance from the two sets of the generating sources. The alternately arranged positive and negative current carrying directions of the shield current carrying means are set in the order of increasing value of &#x3b8;n.

Low-leakage magnetic-field magnet and shield coil assembly

Superconducting magnet and magnetic resonance imaging apparatus using the same

Effect of vibration of a refrigerator on a superconducting coil is reduced to reduce disturbance in an image. A coolant tank for supplying a coolant to coil containers is provided separately from the coil containers, and the refrigerator is placed in the coolant tank, and a coolant circulation passage connects between the coolant tank and the coil containers.

A magnet for use in a magnetic resonance imaging apparatus. The magnet includes magnetic poles and coils. The shape and positioning of the magnetic poles and coils enables provision of a uniform static magnetic field. The magnetic pole is provided with ring-shaped grooves and/or projections which compensate for axi-symmetric components of an inhomogeneous magnetic field and with partial grooves or partial projections not shaped in a ring which compensate for non-axi-symmetric components of the inhomogeneous magnetic field. Since the arrangement of the projections and grooves for compensating for the axi-symmetric and non-axi-symmetric components can also be optimized in design, a space occupied by the magnetic poles can be decreased.

Magnet, a method of adjustment of magnetic field and a magnetic resonance imaging apparatus

A magnetic resonance imaging apparatus is provided with a pair of static magnetic field uniformity controlling members A and B which are disposed adjacent to respective pair of magnetic plates A and B and of which cross sections configured so as to further enhance static magnetic field uniformity in static magnetic field region and a pair of flat plate shaped eddy current suppressing members A and B which are disposed adjacent to respective pair of gradient magnetic field coils A and B and shield influences of gradient magnetic field generated by the gradient magnetic field coils A and B on the static magnetic field uniformity controlling members A and B of pole pieces. The eddy current suppressing members A and B are easily manufactured from a flat plate member simply by cutting the same while following the shape of the gradient magnetic field coils A and B. Further, with the provision of the eddy current suppressing members A and B influences due to eddy current and residual magnetism induced by the gradient magnetic field coils A and B on the static magnetic field uniformity controlling members A and B are suppressed and uniformity in the uniform static magnetic field region is enhanced.

Process and apparatus for producing Nb.sub.3 Al super-conducting wire

A high-temperature oxide superconductor is provided and comprises oxide crystals oriented in a certain direction, the oxide superconductor being substantially free of or containing a controlled amount of foreign phases, a non-superconducting phase and weak superconducting phase which are harmful for superconducting characteristics in the grains of the crystals and at the grain boundaries between the crystals. The foreign phases, if any, are finely and uniformly dispersed in the grains of the oxide crystals and at the grain boundaries. A wire made from the oxide superconductor, a coil from the wire, and a magnetic field generator from the coil are disclosed, the superconductor wire having only a single layer of oxide crystal grains in the thickness direction.

Oxide superconductor, superconducting wire and coil using the same and

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Hitachiota, Japan

Yoshihide Wadayama