Fuji Electric Co., Ltd.

National Research Institute for Metals

Chubu Electric Power Company, Inc.

Doryokuro Kakunenryo Kaihatsu Jigyodan

Michiru Fujita

Tatsuo Take

Tadashi Morita

Toshiaki Watanabe

Akira Fukuzawa

Motoo Yamazaki

Kazuyuki Sakuraya

Makoto Yoshida

Hiroshi Igarashi

Hiroaki Kobayashi

Masaki Sakuma

Kengo Kainuma

Ryuuichi Nagashima

Masao Higuchi

Haruo Ono

Hideaki Tadano

Hirotaka Yoshimatsu

A coin detection antenna includes a substrate and a plurality of air core coils of track shape including a wiring pattern provided on the substrate. The plurality of air core coils is disposed along short-side directions of air cores of the plurality of air core coils such that a smallest coin of coins to be detected crosses at least one of centerlines of the air cores even when the smallest coin is located at any location in a detection range.

Coin detection antenna and coin processing device

A cooling water conduit extending through a segment of a crucible is curved inward in the portion around a molten metal tapping hole.

Levitation melting furnace

A flux for effectively melt-decontaminating a zircaloy contaminated with a radioactive contaminant Pu.sub.2 O.sub.3 is provided. The flux comprises a mixture of a metal flux of a metal (e.g. Ca or Mg) having a higher chemical activity than plutonium at a temperature above the melting point of the zircaloy with a halide flux of metallic compound (e.g. SnF.sub.2, PbF.sub.2, CoF.sub.2, CsF.sub.2) of a halogen element having a higher atomic number than fluorine and has a smaller absolute value of the standard free energy of formation than a fluorination product of plutonium (i.e. PuOF). The addition of the flux to a molten zircaloy causes plutonium contained in the melt to be converted, through a two-step reaction, to PuOF which can be then separated as slag.

Method for melt-decontaminating metal contaminated with radioactive

A superconducting magnet for producing a uniform magnetic field, including a main coil comprising first superconducting coils, and active shield comprising second superconducting coils and arranged in such a manner as to coaxially surround the main coil, and a self-shield comprising magnetic material and arranged in such a manner as to coaxially surround the active shield. The magnetic moment of the active shield is smaller in absolute value than and opposite in direction to the magnetic moment of the main coil.

Superconducting magnet

In addition to a first driving device which moves only a lower crucible, and a first control device which controls the first driving device, a second driving device which changes the vertical relative position of an upper crucible and an induction coil, and a second control device which controls the second driving device are disposed, whereby the relative positions of the upper and lower crucibles and the induction coil can freely be changed. Consequently, the relative positions of the induction coil and the upper and lower crucibles can adequately be set in whole of the operation period from the initial operation stage to the final operation stage, in accordance with the position of a melting zone in the top portion of a material to be melted which grows as a result of continuously charging chips.

Levitating and melting apparatus and method of operating the same

Apparatus to float and melt particularly small pieces of high-melting point metal continuously while making the amount of meltable liquid metal greater than the capacity of a crucible. A conductive crucible having segments includes an upper cylindrical crucible portion and a lower closed-end crucible portion. An induction coil is arranged outside the upper crucible portion, whereas an induction coil is arranged below the induction coil. The lower crucible portion is in contact with the upper crucible portion and located on the inside of the induction coil at the initial melting stage. The lower crucible portion is lowered as a columnar metal grows and solidifies between molten metal and the lower crucible portion. A continuous feeder continuously feeds cold material. A molten metal surface thermometer and a molten metal surface level gauge are arranged above the crucible. The operation of the continuous feeder is regulated within a desired range of values of the molten metal surface thermometer. On the other hand, the lower crucible portion is successively lowered within a desired range of values of the molten metal surface level gauge.

Float melting apparatus and method employing axially movable crucibles

A plurality of segments 12 respectively formed of an electrically insulated conductive material such as copper or the like are disposed inside an induction coil 1 in the peripheral direction of the induction coil 1 to thereby construct a crucible 3. There is formed a small cylindrical hole 4 in the center of the bottom portion of the crucible 3. A magnetic flux is allowed to enter the crucible 3 from slits 15 respectively formed between the hole 4 and segments 12 and is then interlinked with an object to be heated. The slits 15 respectively defined by mutually adjoining segments 12 are arranged such that the width of the bottom portion thereof is greater than that of the cylindrical portion thereof. When the width of the slit in the bottom portion is increased, then a leakage flux to the crucible is increased which in turn increases a levitation force F. If there are further formed bottom slits only in the bottom portions of the segments to thereby increase the number of the slits in the bottom portion to be greater than that of the slits in the cylindrical portion, then the leakage flux is increased to thereby increase the levitation force F, and also the fused metal is supported at multiple points, which increases the stability S thereof.

Levitating and fusing device

A gradient magnetic field coil for generating a gradient magnetic field comprises at least one pair of conductive thin plates placed on a surface of a cylinder and rod conductors for supplying an electric current to at least one pair of conductive thin plates. In case of defining a body center of the cylinder to be an origin, defining a central axis of the cylinder to be a z axis, defining an axis included in the plane, intersecting at the origin and being vertical to the z axis to be an x axis and defining an axis intersecting at the origin and being vertical to the x axis and the z axis to be a y axis, at least one pair of conductive thin plates have a symmetrical shape with respect to an x-y plane and a y-z plane, and the conductive thin plates, each facing to each other, are placed in a symmetrical position with respect to an x-z plane and have a symmetrical shape with respect to an x-z plane. An electric current distribution on conductive thin plates is symmetrical with respect to an x-z plane and each electric current in conductive thin plates flow in an opposite direction to each other.

Coil for generating gradient magnetic field

A high frequency coil is constructed by combining a plurality of unit coil having two saddle shaped coils which are vertically symmetric to each other. Each unit coil is disposed so as to locate the line sections of each saddle shaped coil on an outer peripheral surface of an elliptic cylinder. Assuming the plane perpendicular to the central axis of the elliptic cylinder is an x-y plane, major axis of an ellipse on the x-y plane as x axis and minor axis thereof as y axis, the angle between the x axis and the line extending from origin to the line section located in a first quadrant chosen among the line sections of each unit coil is assumed as .theta.. The optimum angle .theta..sub.op is determined in such a way that when power series expansion relative to y over the magnetic flux density distribution on the y axis of the magnetic flux generated by the high frequency coil is performed, the angle at which the coefficient of the terms with up to degrees of 2N or 2N-2, N is a number of the unit coil, become zero. It is possible to obtain a high frequency magnetic field having exactly uniform magnetic flux density by means of directing .theta. to .theta..sub.op or near by .theta..sub.op.

High frequency coil

A coil for generating a homogeneous magnetic field has a first coil unit composing three pairs of coils each including a common central axis and being symmetric with respect to the center of the central axis and a second coil unit composing two pairs of coils provided outside of and axially with the first coil unit and being symmetric with respect to the center of the central axis. The magnetic moment of the first coil unit is identical in magnitude to and opposite in direction to that of the second coil unit, so that the magnetic field due to leakage flux is substantially cancelled out. Moreover, since each coil composing the first coil unit is selectively located in proper position and the amount of ampere-turn of each coil can be selected, it is possible to reduce to zero the coefficients of terms up to tenth order with respect to the strength distribution of magnetic fields on the central axis generated by the first and the second coil units, resulting in enhancing homogeneity of the magnetic field.

Growing community of inventors

Kawasaki, Japan

Michiru Fujita