Patents by Inventor Raghavan Jayakumar

Raghavan Jayakumar has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5394130
    Abstract: A stable superconducting switch suitable for use in a conduction-cooled superconducting magnet includes a tape wound in a coil with the tape including an Nb.sub.3 Sn conductor sandwiched between stabilizing layers of copper, bronze or brass and wound in layers, with groups of layers separated by a partial layer of electrically conductive material.
    Type: Grant
    Filed: January 7, 1993
    Date of Patent: February 28, 1995
    Assignee: General Electric Company
    Inventors: Bu-Xin Xu, Raghavan Jayakumar, John J. Wollan
  • Patent number: 5001447
    Abstract: A reduced length, high field strength magnet, comprised of a number of superconducting magnet coils has ferromagnetic compensation rings positioned coaxially around the magnet bore axis to reduce axial inhomogeneities. The rings are positioned symmetrically around the bore axis centerpoint. Both the position of the magnet coils and the position of the ferromagnetic compensation rings are determined by an iterative optimization process checked by finite element modeling.
    Type: Grant
    Filed: August 23, 1989
    Date of Patent: March 19, 1991
    Assignee: General Electric Company
    Inventor: Raghavan Jayakumar
  • Patent number: 4896128
    Abstract: A support structure for a superconducting solenoid magnet has a set of five symmetrically and coaxially arranged nonferrous support rings. The central support ring mounts two magnet coils and the other four rings each mount one magnet coil so as to restrain the magnet coils from collapsing toward the center along the magnet bore axis and also to resist radially and circumferentially acting hoop stresses to which the coils are subjected. Tubular struts are symmetrically arranged about the magnet bore axis between adjacent support rings and are seated at their ends in counterbores in the support rings to separate and space apart the support rings. Threaded rods extend through the tubular struts and adjacent support rings to fasten the adjacent rings together.
    Type: Grant
    Filed: November 30, 1988
    Date of Patent: January 23, 1990
    Assignee: General Electric Company
    Inventors: John J. Wollan, Raghavan Jayakumar, Vincent Abruzzo, James Lee, Jr.
  • Patent number: 4812797
    Abstract: A superconducting coil assembly for a nuclear magnetic resonance imaging system has a main coil for producing a static magnetic field within a cylindrical volume. a conventional set of active correction coils are provided to spatially homogenize the magnetic field. A pair of passive compensation coils are electrically connected in series and shorted together. The compensaton coils are inductively coupled to the main coil so that the temporal decay of the current in the main coil induces current in the compensation coils. The magnetic field harmonics produced by this induced current is opposed to the magnetic field harmonics produced in the correction coils by main coil decay. The compensation coil thereby counteracts the inhomogeneity effects from the main coil current decay.
    Type: Grant
    Filed: March 22, 1988
    Date of Patent: March 14, 1989
    Assignee: General Electric Company
    Inventor: Raghavan Jayakumar