Patents by Inventor George Bekefi

George Bekefi 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: 5363054
    Abstract: A double beam cyclotron maser comprising two electron guns for introducing two electron beams traveling parallel to each other at different speeds into an electron drift tube/waveguide. The beams have respectively different electron cyclotron space-charge harmonics. A solenoid maintains a magnetic field parallel to the direction of propagation of the electron beams while a magnetic wiggler field initially imparts a transverse force to the electrons such that they propagate down the drift tube with a helical gyration. The magnetic fields, electron beam velocities, and beam space charge harmonics are adjustable to set the interaction frequency at which amplification of electromagnetic radiation can occur. The waveguide is a slow wave structure so configured as to slow the signal from the magnetron to match the phase velocity of the double stream cyclotron space-charge wave.
    Type: Grant
    Filed: February 27, 1992
    Date of Patent: November 8, 1994
    Assignee: Massachusetts Institute of Technology
    Inventor: George Bekefi
  • Patent number: 5280490
    Abstract: An electromagnetic radiation amplification device comprising an electron gun for introducing a stream of electrons into an electron drift tube/wavequide in which an axial magnetic field and a wiggler magnetic field have been induced to impart a helical gyration to the electrons as they travel parallel to the tube. The axial, or guide, magnetic field is directed in the direction opposite to the direction of propagation of the electrons if the electrons have a right handed helical gyration and is directed in the direction of propagation of the electrons if the electrons have a left handed helical gyration.
    Type: Grant
    Filed: November 22, 1991
    Date of Patent: January 18, 1994
    Assignee: Massachusetts Institute of Technology
    Inventors: Manoel Conde, George Bekefi
  • Patent number: 4835391
    Abstract: A system which couples Cerenkov emission with a gated electrooptic effect to allow viewing of Cerenkov radiation in sub nanosecond time-scales is disclosed. Cerenkov radiation is generated by transmitting an electron beam through a transparent medium with a high index of refraction. The Cerenkov radiation is then gated into a sample pulse of subanosecond duration by an electrooptic crystal which has an index of refraction controlled by an electric field. the electrooptic crystal is opaque to the Cerenkov radiation until receiving a 6.0 kV voltage for about 750 picoseconds, upon which a pulsed sample of Cerenkov radiation is transmitted to a display system.
    Type: Grant
    Filed: July 1, 1987
    Date of Patent: May 30, 1989
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Frederick Hartemann, George Bekefi
  • Patent number: 4530096
    Abstract: A source of coherent electromagnetic radiation capable of generating or amplifying waves in the centimeter, millimeter, and submillimeter wavelength range. An annular beam of gyrating electrons is produced which is then compressed to its paraxial position by means of a solenoid magnetic field around the wave-guide. This electron beam is also subjected to a transverse motion in an interaction region by a longitudinal rippled (wiggler) magnetic field. Such a field is generated by a periodic assembly of rings magnetized in the axial direction. The electron beam during its accelerated motion generates or amplifies coherent electromagnetic radiation in the centimeter, millimeter, or submillimeter range.
    Type: Grant
    Filed: November 15, 1982
    Date of Patent: July 16, 1985
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: George Bekefi, Wayne A. McMullin
  • Patent number: 4465953
    Abstract: The rippled-field magnetron is a novel cross-field millimeter wave source in which electrons move under the combined action of a radial electric field, an axial magnetic field and an azimuthally periodic wiggler magnetic field, .vertline.B.sub.w .vertline. cos (N.theta.) oriented transversely to the flow. Estimates are given of the frequency and growth rate of the free electron laser (FEL) type of instability excited in this smooth-bore magnetron configuration.
    Type: Grant
    Filed: September 16, 1982
    Date of Patent: August 14, 1984
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: George Bekefi
  • Patent number: 4200821
    Abstract: An intense relativistic crossed field device in a nested configuration wherein a field emission cathode is nested within a segmented annular anode with an annular gap separating the two.
    Type: Grant
    Filed: March 17, 1977
    Date of Patent: April 29, 1980
    Assignee: Massachusetts Institute of Technology
    Inventors: George Bekefi, Thaddeus J. Orzechowski