Abstract: A particle therapy system includes an accelerator 1 which generates a particle beam for extraction, an irradiation apparatus 21 which irradiates the particle beam to an irradiation target 26, a gantry 18 which rotates together with the irradiation apparatus 21, and an MRI apparatus 50 which rotates together with the gantry 18. The MRI apparatus 50 includes a magnetic circuit composed of an iron core 60 and a plurality of coils 61 serving as a magnetic flux source. The iron core 60 includes two oppositely disposed magnetic poles 63A and 63B, and a return yoke 64 for connecting the magnetic poles 63A and 63B. The magnetic poles 63A, 63B have cavities 65A, 65B. The particle beam passing through the cavity 65A is irradiated to the irradiation target 26.

Abstract: A particle therapy system includes an accelerator 1 which generates a particle beam for extraction, an irradiation apparatus 21 which irradiates the particle beam to an irradiation target 26, a gantry 18 which rotates together with the irradiation apparatus 21, and an MRI apparatus 50 which rotates together with the gantry 18. The MRI apparatus 50 includes a magnetic circuit composed of an iron core 60 and a plurality of coils 61 serving as a magnetic flux source. The iron core 60 includes two oppositely disposed magnetic poles 63A and 63B, and a return yoke 64 for connecting the magnetic poles 63A and 63B. The magnetic poles 63A, 63B have cavities 65A, 65B. The particle beam passing through the cavity 65A is irradiated to the irradiation target 26.

Abstract: A computer executes: calculating a first volume distribution (v.d.) of magnetic materials on a shim tray, based on a first magnetic field strength distribution (m.f.s.d.) in a magnetic field space (S3); acquiring a first composite distribution (c.d.) representing a volume by addition of volumes of magnetic materials for each region of the shim tray, and positions of the regions (S5); calculating a virtual m.f.s.d. created by magnetic materials supposed to be arranged as in the first c.d. (S8); calculating a second m.f.s.d. by addition of the first m.f.s.d. and the virtual m.f.s.d. (S9); calculating a second v.d. of magnetic materials on the shim tray, based on the second m.f.s.d. (S3); acquiring a second c.d. representing a volume by addition of volumes of magnetic materials for each region, and positions of the regions (S5); and displaying the positions of regions and the volumes in the first c.d. and second c.d. (S10).

Abstract: This superconducting magnet includes: a superconducting coil that is formed by winding a first superconducting wire rod; a second superconducting wire rod, which is disposed by being thermally in contact with and electrically insulated from the superconducting coil, and which has a superconducting transition temperature that is lower than that of the first superconducting wire rod; voltage terminals that are disposed at a plurality of areas of the second superconducting wire rod; a voltmeter connected to the voltage terminals; and a switch circuit connected to the voltmeter. The switch circuit interrupts a current when receiving an output from the voltmeter, the current being one that is to be supplied to the superconducting coil.

Abstract: In a gradient magnetic field coil device including: a plurality of main coils generating in an imaging region of a magnetic field resonance imaging device a magnetic field distribution in which an intensity linearly inclines; and a plurality of shield coils, arranged on an opposite side of the imaging region across the main coils, suppressing residual magnetic field generated by the main coils on the opposite side. The plurality of main coils and the plurality of shield coils are connected in series. The device further includes a plurality of current adjusting devices, connected to the shield coils in parallel, independently adjusting currents flowing through the shield coils, respectively, to enhance symmetry of the residual magnetic field. The gradient magnetic field coil device is provided which can suppress generation of eddy current magnetic field even if there is a relative position deviation between the main coils and shield coils.

Abstract: A first superconducting coil (11) has a winding frame (13), a winding part (16) of a superconductor wire material (15) wound around the winding frame (13), and an insulating plate (25) inserted into the gap between the winding frame (13) and the winding part (16) of the superconductor wire material (15). The insulating plate (25) comprises a first insulating plate (21) and a second insulating plate (23) divided in the thickness direction. A low friction material (27) comprising a fluororesin sheet is inserted between the separation faces of the first insulating plate (21) and the second insulating plate (23) facing each other. It is thereby possible to provide a superconducting coil capable of simultaneously preventing quenching and reducing the number of manufacturing man-hours.

Abstract: This superconducting magnet includes: a superconducting coil that is formed by winding a first superconducting wire rod; a second superconducting wire rod, which is disposed by being thermally in contact with and electrically insulated from the superconducting coil, and which has a superconducting transition temperature that is lower than that of the first superconducting wire rod; voltage terminals that are disposed at a plurality of areas of the second superconducting wire rod; a voltmeter connected to the voltage terminals; and a switch circuit connected to the voltmeter. The switch circuit interrupts a current when receiving an output from the voltmeter, the current being one that is to be supplied to the superconducting coil.

Abstract: A superconducting magnet apparatus is provided, which comprises a superconducting coil, an induction coil to be in inductive coupling with the superconducting coil, a first refrigerant vessel charged with a first refrigerant in which the superconducting coil is installed; and a second refrigerant vessel charged with a second refrigerant having a melting temperature higher than or a boiling temperature higher than a boiling temperature of the first refrigerant, the second refrigerant vessel in which the induction coil is installed, wherein the second refrigerant vessel is thermally isolated from the first refrigerant vessel.

Abstract: A superconducting magnet device is configured to include: a refrigerant circulation flowpath in which a refrigerant (R) circulates; a refrigerator for cooling vapor of the refrigerant (R) in the refrigerant circulation flowpath; a superconducting coil cooled by the circulating refrigerant (R); a protective resistor thermally contacting the superconducting coil and having an internal space (S); a high-boiling-point refrigerant supply section for supplying a high-boiling-point refrigerant having a higher boiling point than the refrigerant (R) and frozen by the refrigerant (R) to the internal space (S) in the protective resistor; and a vacuum insulating container for at least accommodating the refrigerant circulation flowpath, the superconducting coil, and the protective resistor.

Abstract: A superconducting magnet apparatus includes: a bobbin around which a superconducting coil is wound, the bobbin serving as a protective resistor; a persistent current switch for supplying a persistent current to the superconducting coil; a first closed circuit with the superconducting coil and the persistent current switch connected in series to the coil; and a second closed circuit with the superconducting coil and the bobbin connected in series to the coil.

Abstract: A measured error magnetic field distribution is divided into eigen-mode components obtained by a singular decomposition and iron piece arrangements corresponding to respective modes are combined and arranged on a shim-tray. An eigen-mode to be corrected is selected in accordance with an attainable magnetic field accuracy (homogeneity) and appropriateness of arranged volume of the iron pieces. Because the adjustment can be made with the attainable magnetic field accuracy (homogeneity) being known, an erroneous adjustment can also be known, and the adjustment is automatically done during repeated adjustments. As a result, an apparatus with a high accuracy can be provided. In addition, there is an advantageous effect of being able to detect a poor magnet earlier by checking the attainable homogeneity.

Abstract: A computer executes: calculating a first volume distribution (v.d.) of magnetic materials on a shim tray, based on a first magnetic field strength distribution (m.f.s.d.) in a magnetic field space (S3); acquiring a first composite distribution (c.d.) representing a volume by addition of volumes of magnetic materials for each region of the shim tray, and positions of the regions (S5); calculating a virtual m.f.s.d. created by magnetic materials supposed to be arranged as in the first c.d. (S8); calculating a second m.f.s.d. by addition of the first m.f.s.d. and the virtual m.f.s.d. (S9); calculating a second v.d. of magnetic materials on the shim tray, based on the second m.f.s.d. (S3); acquiring a second c.d. representing a volume by addition of volumes of magnetic materials for each region, and positions of the regions (S5); and displaying the positions of regions and the volumes in the first c.d. and second c.d. (S10).

Abstract: A superconducting magnet apparatus includes: a bobbin around which a superconducting coil is wound, the bobbin serving as a protective resistor; a persistent current switch for supplying a persistent current to the superconducting coil; a first closed circuit with the superconducting coil and the persistent current switch connected in series to the coil; and a second closed circuit with the superconducting coil and the bobbin connected in series to the coil.

Abstract: A superconducting magnet device is configured to include: a refrigerant circulation flowpath in which a refrigerant (R) circulates; a refrigerator for cooling vapor of the refrigerant (R) in the refrigerant circulation flowpath; a superconducting coil cooled by the circulating refrigerant (R); a protective resistor thermally contacting the superconducting coil and having an internal space (S); a high-boiling-point refrigerant supply section for supplying a high-boiling-point refrigerant having a higher boiling point than the refrigerant (R) and frozen by the refrigerant (R) to the internal space (S) in the protective resistor; and a vacuum insulating container for at least accommodating the refrigerant circulation flowpath, the superconducting coil, and the protective resistor.

Abstract: In a gradient magnetic field coil device including: a plurality of main coils generating in an imaging region of a magnetic field resonance imaging device a magnetic field distribution in which an intensity linearly inclines; and a plurality of shield coils, arranged on an opposite side of the imaging region across the main coils, suppressing residual magnetic field generated by the main coils on the opposite side. The plurality of main coils and the plurality of shield coils are connected in series. The device further includes a plurality of current adjusting devices, connected to the shield coils in parallel, independently adjusting currents flowing through the shield coils, respectively, to enhance symmetry of the residual magnetic field. The gradient magnetic field coil device is provided which can suppress generation of eddy current magnetic field even if there is a relative position deviation between the main coils and shield coils.

Abstract: An eigen-mode to be corrected is selected in accordance with an attainable magnetic field accuracy (homogeneity) and appropriateness of arranged volume of the iron pieces. Because the adjustment can be made with the attainable magnetic field accuracy (homogeneity) being grasped, an erroneous adjustment can be grasped, and the adjustment is automatically done during repeated adjustment. When the magnetic field adjustment is carried out with support by the method of the present invention according to the first and second embodiments or an apparatus including this method therein, the magnetic field adjustment can be surely completed. As a result, the apparatus with a high accuracy can be provided. In addition, there is an advantageous effect of earlier detection of a poor magnet by checking the attainable homogeneity. They are applicable to magnet devices for the horizontal magnetic field type, being an open type MRI, and vertical magnetic field type MRI.

Abstract: The magnetic field homogeneity adjusting device (20) is characterized by comprising a magnetic field distribution measuring unit (21) for measuring the magnetic field distribution in the magnetic field space, a temperature variation calculating unit (22) for calculating the temperature variation of the ferromagnetic bodies needed to improve the homogeneity of the magnetic field space based on the measured magnetic field distribution, and a temperature control unit (12) for setting a temperature control value of the ferromagnetic bodies according to the calculated temperature variation.

Abstract: The active shield superconducting electromagnet apparatus includes: a main switching circuit in which first and second main coils, first and second shield coils, and a first superconducting persistent current switch are connected in series; a sub switching circuit in which a bypass circuit, in which a superconducting fault current limiter and a second superconducting persistent current switch are connected in series, are connected to a series circuit of the first main coil and the second main coil in parallel; a first closed circuit in which at least one of the first main coil and the first shield coil, and a first quench protection circuit are connected in series; and a second closed circuit in which one of the second main coil and the second shield coil, and a second quench protection circuit are connected in series.

Abstract: A measured error magnetic field distribution is divided into eigen-mode components obtained by a singular decomposition and iron piece arrangements corresponding to respective modes are combined and arranged on a shim-tray. An eigen-mode to be corrected is selected in accordance with an attainable magnetic field accuracy (homogeneity) and appropriateness of arranged volume of the iron pieces. Because the adjustment can be made with the attainable magnetic field accuracy (homogeneity) being known, an erroneous adjustment can also be known, and the adjustment is automatically done during repeated adjustments. As a result, an apparatus with a high accuracy can be provided. In addition, there is an advantageous effect of being able to detect a poor magnet earlier by checking the attainable homogeneity.

Abstract: On the basis of the magnetic field intensity distribution of a magnetic field space (3), in order to homogenize the distribution, the positions and the volumes of magnetic material shims (such as shim bolts (27)) which have to be arranged on shim trays (17, 18) are first computed on a minute computational grid. Subsequently, from the distributions of the computed positions and volumes of the magnetic material shims, the local maximum values and local minimum values thereof are extracted, and the distribution areas of the volumes of the magnetic material shims with each value as the center are extracted. Then, the volumes of the magnetic materials distributed in the distribution areas are added. Finally, the results of the addition are displayed with the positions of corresponding local maximum values or the positions of corresponding local minimum values.