# US 2012/0068795 A1 · Magnet assemblies and methods for making the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2012/0068795 A1 - Document ID: US20120068795A1 - Status: Published application - Kind: A1 - Application number: 13/218,517 - Filed: 2011-08-26 - Published: 2012-03-22 - Earliest claimed: 2010-09-17 - Assignees: General Electric Company - Inventors: Anbo WU; Yan Zhao; Chao Yang; Evangelos Trifon Laskaris; Xianrui Huang - Web page: https://patentgrep.com/patent/US20120068795A1 ## CPC - G01R 33/3815: with superconducting coils, e.g. power supply therefor - G01R 33/421: of main or gradient magnetic field - Y10T 29/49014: Superconductor - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A superconducting magnet assembly is provided. The superconducting magnet assembly includes a superconducting magnet configured to generate a static magnetic field, an iron shield configured to shield the superconducting magnet, and a magnetic gradient coil assembly configured to generate a gradient magnetic field. The superconducting magnet assembly further includes one or more magnetic lamination elements disposed on the iron shield to reduce eddy current induced by the gradient magnetic field in the iron shield. A method is also presented. ## Claims ### Claim 1 A superconducting magnet assembly, comprising: a superconducting magnet configured to generate a static magnetic field; an iron shield configured to shield the superconducting magnet; a magnetic gradient coil assembly configured to generate a gradient magnetic field; and one or more magnetic lamination elements disposed on the iron shield to reduce eddy currents induced by the gradient magnetic field in the iron shield. ### Claim 2 (depends on 1) The superconducting magnet assembly of claim 1, wherein the superconducting magnet assembly is used in a magnetic resonance imaging system, and wherein the superconducting magnet comprises one or more superconducting winding coils. ### Claim 3 (depends on 1) The superconducting magnet assembly of claim 1, wherein each of the one or more magnetic lamination elements comprises two or more layers of one or more magnetic materials. ### Claim 4 (depends on 3) The superconducting magnet assembly of claim 3, wherein at least one of the one or more magnetic lamination elements are disposed on the iron shield along a direction parallel to a laminating direction of the at least one of the one or more magnetic lamination elements. ### Claim 5 (depends on 3) The superconducting magnet assembly of claim 3, wherein the one or more magnetic materials comprises silicon steel, amorphous magnetic materials, and combination thereof. ### Claim 6 (depends on 1) The superconducting magnet assembly of claim 1, wherein the one or more magnetic lamination elements are disposed on an interior surface of the iron shield in a configuration of one or more layers, wherein at least one of the one or more layers comprises more than one magnetic lamination element, and wherein one or more non-magnetic gaps are defined between adjacent magnetic lamination elements in the at least one layer. ### Claim 7 (depends on 6) The superconducting magnet assembly of claim 6, wherein the more than one magnetic lamination element in the at least one layer are disposed on the iron shield along a direction of the static magnetic field generated by the superconducting magnet, and wherein the one or more non-magnetic gaps are defined along the direction of the static magnetic field. ### Claim 8 (depends on 7) The superconducting magnet assembly of claim 7, further comprising one or more fiberglass-reinforced plastics disposed within the respective one or more non-magnetic gaps. ### Claim 9 (depends on 6) The superconducting magnet assembly of claim 6, wherein the one or more magnetic lamination elements are disposed on the iron shield in the configuration of two or more layers, and wherein at least one magnetic lamination element in an upper layer covers at least one of the one or more non-magnetic gaps defined in a lower layer. ### Claim 10 (depends on 9) The superconducting magnet assembly of claim 9, farther comprising one or more layers of fiberglass disposed between adjacent layers of the one or more magnetic lamination elements. ### Claim 11 (depends on 1) The superconducting magnet assembly of claim 1, wherein the iron shield encases the superconducting magnet, and wherein the one or more magnetic lamination elements are disposed on inner surface of the iron shield. ### Claim 12 (depends on 11) The superconducting magnet assembly of claim 11, wherein the iron shield has a substantially cylindrical shape and comprises a body and a pair of flanges disposed on two ends of the body, and wherein the one or more magnetic lamination elements are disposed on at least one of the body and the pair of the flanges. ### Claim 13 A superconducting magnet assembly, comprising: a superconducting magnet configured to generate a static magnetic field; an iron shield configured to shield the superconducting magnet; a magnetic gradient coil assembly configured to generate a gradient magnetic field; a plurality of magnetic lamination elements disposed on the iron shield; and one or more non-magnetic gaps defined between adjacent magnetic lamination elements along a direction of the static magnetic field generated by the superconducting magnet. ### Claim 14 (depends on 13) The superconducting magnet assembly of claim 13, wherein at least one of the plurality of the magnetic lamination elements are disposed on the iron shield along a direction parallel to a laminating direction of the at least one of the plurality of magnetic lamination elements. ### Claim 15 (depends on 13) The superconducting magnet assembly of claim 13, wherein the plurality of the magnetic lamination elements are disposed on the iron shield in a configuration of two or more layers, and wherein at least one magnetic lamination element in an upper layer covers at least one of the one or more non-magnetic gaps defined in a lower layer. ### Claim 16 (depends on 13) The superconducting magnet assembly of claim 13, wherein the iron shield has a cylindrical shape and comprises a body and a pair of flanges disposed on two ends of the body, wherein each of the body and the pair of the flanges are formed with a plurality of separated elements. ### Claim 17 A method, comprising: providing a superconducting magnet configured to generate a static magnetic field; providing an iron shield configured to shield the superconducting magnet; providing a magnetic gradient coil assembly configured to generate a gradient magnetic field; and providing one or more magnetic lamination elements disposed on the iron shield to reduce eddy current induced by the gradient magnetic field in the iron shield. ### Claim 18 (depends on 17) The method of claim 17, wherein at least one of the one or more magnetic lamination elements are disposed on the iron shield along a direction parallel to a laminating direction of the at least one of the one or more magnetic lamination elements. ### Claim 19 (depends on 17) The method of claim 17, wherein the one or more magnetic lamination elements are disposed on the iron shield in a configuration of one or more layers, wherein at least one of the one or more layers comprises more than one magnetic lamination element, and wherein one or more non-magnetic gaps are defined between adjacent magnetic lamination elements in the at least one layer. ### Claim 20 (depends on 19) The method of claim 19, wherein the more than one magnetic lamination element in the at least one layer are disposed on the iron shield along a direction of the static magnetic field generated by the superconducting magnet, and wherein the one or more non-magnetic gaps are defined along the direction of the static magnetic field.