Hitachi Global Storage Technologies Netherlands B.v.

Riken Corporation

Hgst Netherlands, B.v.

Hitachi, Ltd.

Sumitomo Electric Industries, Limited

National Institute for Materials Science

Hitachi Global Storage Technologies Japan, Ltd.

Mitsubishi Cable Industries, Ltd.

Chiba University

Japan Superconductor Technology Inc.

Tokkyokiki Corporation

Hideaki Maeda

Masafumi Mochizuki

Yoshinori Yanagisawa

Takehiko Hamaguchi

Hiroyasu Tanabe

Hideki Zaitsu

Shuji Nishida

Masato Takahashi

Yasutaka Nishida

Kazuhisa Shishida

Xinzhe Jin

Hideki Nakagome

Kouki Uefune

Shigeyuki Yokoyama

Atsushi Kikugawa

Tatsuoki Nagaishi

Yoshihisa Kamo

Mikio Suzuki

Naoki Satoh

Takako Hayakawa

Toru Aida

Masato Taniguchi

Yoshiju Watanabe

Reiko Arai

Masaru Muranishi

Ikuya Tagawa

Kotaro Ohki

Yoshiyuki Hirono

Hiroyuki Kamibayashi

Masaomi Ikeda

Masashi Yasuda

Takao Matsui

Tadashi Shimizu

Mamoru Hamada

Yukiya Shimizu

Kazuaki Usui

Yasuyuki Ito

Shinji Matsumoto

Tetsuo Yuki

Mao Nishiyama

Takashi Konishi

Fumiaki Itojima

Masaki Tsuchiya

Jun Ohno

Kenjiro Hashi

Gen Nishijima

Shintetsu Kanazawa

Toshihiko Tsunokawa

Takashi Noguchi

Liping Shen

Kohji Nakao

Masahiko Koizumi

Yosuke Urakami

Keita Oobuchi

Takaaki Izumida

Shuhsuke Kurihara

A superconducting magnet according to one embodiment includes: a coil including a superconducting layer having a first portion and a second portion, and a joining portion; and a cryostat in which the coil is stored. The first portion and the second portion are located in a termination portion. The superconducting layer forms a closed loop by superconducting joining of the first portion and the second portion at the joining portion. The superconducting layer is made of a high-temperature superconductor. A current flows through the joining portion in a superconducting state when a magnetic field equal to or greater than 1.0 tesla and equal to or less than 5.0 tesla is applied to the joining portion at 77 kelvin. The cryostat is configured such that a temperature inside the cryostat is equal to or greater than 2.0 kelvin and equal to or less than 77 kelvin.

Superconducting magnet

In a high-temperature superconducting (HTS) wire connection assembly in which HTS wires each including a HTS layer are connected to each other, a first HTS wire and a second HTS wire that face each other are connected to each other at a plurality of joint portions separated from each other along a longitudinal direction of the first HTS wire and the second HTS wire. Each of the plurality of joint portions may preferably have any one of a rectangle shape, a rounded rectangle shape, and an ellipse shape, and it is preferable to satisfy 0.1&#x3c;L/W&#x3c;1.5, and is more preferable to satisfy 0.25&#x3c;L/W&#x3c;0.75 when a length in the longitudinal direction of the HTS wire is taken as L and a length in a width direction of the HTS wire is taken as W. It is also preferable that W and/or L monotonously increase from upstream side toward downstream side along the longitudinal direction of the wire.

High-temperature superconducting wire connection assembly

A superconducting magnet device including a superconducting coil formed of a high-temperature superconducting wire, a power supply which supplies current to the superconducting coil, and a protector capable of forming a short-circuit path which short-circuits both ends of the superconducting coil to each other is installed. Current is made to flow from the power supply to the superconducting coil in a superconducting state, and the superconducting coil thereby generates a magnetic field. After the magnetic field is generated, when an abnormality of the superconducting magnet device is detected, or when the power supply and the superconducting coil are disconnected from each other, the short-circuit path is formed by the protector.

Superconducting magnet device and method for limiting current decrease in case of abnormality therein

A magnetic field generation apparatus includes a main coil and a variable-current correction coil. The main coil is formed by winding a ReBCO-based superconductive wire rod and generates a magnetic field in a measurement space. The variable-current correction coil is variable in a value of a current, coaxial with the main coil and disposed inside the main coil, and generates a magnetic field which corrects a uniformity of the magnetic field generated by the main coil.

Magnetic field generation device

The method is for manufacturing a high temperature multi-filamentary superconducting tape wire having an oxide superconducting layer formed on a tape-shaped metal substrate with an intermediate layer therebetween and a metal stabilizing layer formed on the oxide superconducting layer, wherein one or more lengthwise slits are formed in the oxide superconducting layer and the intermediate layer and no slits are formed in the metal substrate and the stabilizing layer. The method includes: a step for preparing a high temperature superconducting wire material having an oxide superconducting layer formed on a tape-shape metal substrate with an intermediate layer therebetween and a stabilizing layer formed on the oxide superconducting layer; and a step for applying a load to the high temperature superconducting wire material to form slits. The method enables simple manufacturing of a high temperature superconducting wire material having a finer superconducting layer without sacrificing superconducting performance and mechanical strength.

High temperature superconducting multicore tape wire, and manufacturing method thereof and manufacturing device

Provided is a low-resistance connection body for a high-temperature superconducting wire, in which a high-temperature superconducting bulk body and a high-temperature superconducting wire including a high-temperature superconducting layer are connected to each other, wherein a melting point of the high-temperature superconducting layer is higher than a melting point of the high-temperature superconducting bulk body; the high-temperature superconducting layer and the high-temperature superconducting bulk body are in contact at a connection site of the high-temperature superconducting wire and the high-temperature superconducting bulk body; and a surface of the high-temperature superconducting bulk body that is in contact with the high-temperature superconducting layer is crystallized due to crystal growth. Two high-temperature superconducting wires can be connected, with low resistance, through connection of the two high-temperature superconducting wires to one high-temperature superconducting bulk.

Low-resistance connection body for high-temperature superconducting wire material and connection method

In a coated high-temperature superconducting wirein which a superconducting yttrium-based wire (high-temperature superconducting wire)having a rectangular cross section is coated by an insulating layer, the insulating layeris an electrodeposited film made of block copolymerized polyimide which contains siloxane bonds in a polyimide main chain and which has molecules with anionic groups. A coil formed from the superconducting yttrium-based wireis impregnated with epoxy resin, and the epoxy resin is cured. The coil is configured such that the epoxy resin is completely separated from the superconducting yttrium-based wireby the insulating layer

Coated high-temperature superconducting wire and high-temperature superconducting coil including the same

In one embodiment, a magnetic disk drive includes a magnetic disk having data tracks, a magnetic head, a motion mechanism for moving the magnetic head, and a controller. The controller adds a value to a rewrite parameter for a rewrite region based on a number of writes to data tracks related to the rewrite region, the value is chosen to reflect a degree of influence the number of writes have on the rewrite region, and the magnetic head rewrites data of the rewrite region when the rewrite parameter is greater than a threshold. In another embodiment, a method includes writing data tracks in a rewrite region, defining values reflecting a degree(s) of influence on the rewrite region, adding the values to a rewrite parameter upon writing data to the data tracks, determining that the rewrite parameter has reached or exceeded a threshold and rewriting data in the rewrite region.

Magnetic disk drive and data rewrite methods

Embodiments of the present invention provide a magnetic head for perpendicular magnetic recording, and a magnetic disk apparatus capable of preventing data erasure caused by alignment marks. In an embodiment, the magnetic head includes a head element including at least a main pole having a pole face on a flying surface and an auxiliary pole; alignment marks made of a magnetic material and used to detect the amount of lapping work when lapping the pole face of the main pole; and members made of a magnetic material, continuously extending in either direction with respect to the position of the main pole from within the alignment marks outward at least beyond the alignment marks.

Magnetic head and magnetic disk apparatus

Embodiments of the invention reduce generation of a magnetic field with a polarity reverse to that of the recording magnetic field, without deteriorating a gradient in the magnetic field. An embodiment of a magnetic disk device according to the present invention suppresses deviation and erase of already recorded data. In an embodiment, the perpendicular magnetic recording head includes the main magnetic pole, an auxiliary magnetic pole, a trailing shield disposed on the trailing side of the main magnetic pole with a non-magnetic film placed in-between, and side shields disposed on both the sides of the main magnetic pole in the direction of the track width with a non-magnetic film placed in-between. The trailing shield has on the trailing side a portion where film thickness is thinner on the trailing side than the thickness of its element in the height direction in its position facing the main magnetic pole. Adoption of this configuration allows suppression of generation of the magnetic field having a polarity reverse to that of the recording magnetic field, without deteriorating the magnetic field gradient. Also in the portion where the side shields face the main magnetic pole, the side shields have the portion where the film is thinned down in thickness.

Perpendicular magnetic recording head, magnetic head, and magnetic disk device mounted with these heads

A method for re-injecting low density gas into a disk drive including a hermetically sealed disk enclosure. The method includes providing a disk drive including a hermetically sealed disk enclosure. In addition, the method includes re-injecting low density gas from a hole penetrating the hermetically sealed disk enclosure from an exterior of the disk drive to an interior of the disk drive. Moreover, the method includes covering the hole with a sealing label including a metal layer and an adhesive layer.

Disk drive and method of re-injecting low density gas in a hermetically sealed disk enclosure of a disk drive

A head-slider configured to fly in proximity to a recording surface of a magnetic-recording disk. The head-slider includes a write element including a main pole configured to generate a magnetic-recording field from a pole tip of the main pole in a first localized portion of the magnetic-recording disk. The head-slider also includes a magnetic-recording assistance element configured to provide energy to a second localized portion of the magnetic-recording disk in order to increase reversibility of a magnetization in a first localized portion of the magnetic-recording disk. A width of the pole tip of the main pole on a leading-edge side is wider than a width of the pole tip of the main pole on a trailing-edge side.

Energy-assisted magnetic-recording head having a magnetic-recording assistance element disposed to lower magnetic-recording field for reversing magnetization in a magnetic-recording disk

A hard-disk drive. The hard-disk drive includes a magnetic-recording disk including tracks on which a plurality of patterned bit-cells that are isolated magnetically are aligned at predetermined alignment pitches. The hard-disk drive includes a magnetic-recording head which is configured to follow tracks, and to write and to read data. The hard-disk drive includes a signal-processing unit which is configured to generate a recording signal based on a write-clock signal with cycles corresponding to alignment pitches of patterned bit-cells, and to output a recording signal. The hard-disk drive includes a phase-detecting unit which is configured to detect a phase of the write-clock signal when the magnetic-recording head reaches an end point of a predetermined range. The hard disk drive includes a determination-processing unit which is configured to determine success of data writing based on a difference between an expected value and a detected value of the phase of the write-clock signal.

Hard-disk drive and control method for magnetic recording on a patterned medium of the hard-disk drive

A hard-disk drive. The hard-disk drive includes a magnetic-recording disk in which tracks adjacent to each other are magnetically separated, a spindle motor which drives the magnetic-recording disk, a magnetic-recording head equipped with write element and read element, an actuator for positioning the magnetic-recording head on a predetermined track on the magnetic-recording disk, and a control unit. The control unit is configured to store information about an over-write-only track that is provided for a plurality of tracks including n consecutive tracks in at least a partial radial area of the magnetic-recording disk and an offset amount. In a radial area of the magnetic disk where the over-write-only track is located, the control unit is configured to record with an offset by an offset amount from a center of a track toward the over-write-only track with respect to n&#x2212;1 tracks of the plurality of n tracks, excluding the over-write-only track.

Hard-disk drive

A magnetic recording device according to one embodiment includes a magnetic recording medium having a magnetic recording layer; a recording element positioned on a head slider; an assistance element for supplying assistance energy to an area on the recording layer to which a recording magnetic field generated by the recording element is applied, the assistance element being positioned on the head slider; and a controller for controlling a size of an assistance area from the assistance element in accordance with a position of the head slider in a radial direction of the magnetic recording medium. Additional systems and methods are also presented.

Magnetic recording device and magnetic recording method thereof

Growing community of inventors

Kanagawa, Japan

Hideaki Maeda