Patents by Inventor Albert E. Litherland

Albert E. Litherland 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: 7365340
    Abstract: The present invention comprehends a compact and economical apparatus for producing high intensities of a wide variety of wanted positive and negative molecular and atomic ion beams that have been previously impossible to previously produce at useful intensities. In addition, the invention provides a substantial rejection of companion background ions that are frequently simultaneously emitted with the wanted ions. The principle underlying the present invention is resonance ionization-transfer where energy differences between resonant and non-resonant processes are exploited to enhance or attenuate particular charge-changing processes. This new source technique is relevant to the fields of Accelerator Mass Spectroscopy; Molecular Ion Implantation; Generation of Directed Neutral Beams; and Production of Electrons required for Ion Beam Neutralization within magnetic fields.
    Type: Grant
    Filed: July 20, 2005
    Date of Patent: April 29, 2008
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Kenneth H. Purser, Albert E. Litherland, Norman L. Turner
  • Patent number: 5569915
    Abstract: A highly sensitive spectrometer system having inherently low backgrounds is described. In this new molecular accelerator mass spectrometry procedure, negative molecules containing the isotope of interest are accelerated using a tandem accelerator. Subsequent electron stripping and analysis stages outside of the accelerator fragment the molecules and eliminate mass upon charge ambiguities. The combination results in a cost effective accelerator mass spectrometer with high sensitivity and low backgrounds.
    Type: Grant
    Filed: April 14, 1995
    Date of Patent: October 29, 1996
    Inventors: Kenneth H. Purser, Linas R. Kilius, Albert E. Litherland, John C. Rucklidge, Xiaolei Zhao
  • Patent number: 5386116
    Abstract: Resonant charge transfer is used to reduce isobaric interferences in accelerator mass spectrometry.
    Type: Grant
    Filed: September 24, 1993
    Date of Patent: January 31, 1995
    Inventors: Linas R. Kilius, Albert E. Litherland
  • Patent number: 5013923
    Abstract: The invention comprises of four magnet system for dispersing and recombining precisely several isotopes for injection into a tandem accelerator. The precise horizontal focusing of the ions is achieved magnetically using curved boundaries of the magnets which have normal entrance and exit boundaries for the central trajectories. The precise vertical focusing is achieved mainly by the electric slot lenses in the first version, with small adjustments of the focusing of the isotopes, other than the central trajectory isotope, by curved boundaries of the magnet. It is the use of the electric slot lenses, or a similar electric device with one dimensional focusing, which in part decouples the focusing action in the vertical plane from the horizontal plane, that permits the use of four fold magnetic symmetry and boundary curvature to accomplish true recombination of the isotopes in a practical and compact device.
    Type: Grant
    Filed: March 1, 1990
    Date of Patent: May 7, 1991
    Assignee: University of Toronto Innovations Foundation
    Inventors: Albert E. Litherland, Linas R. Kilius
  • Patent number: 4489237
    Abstract: A highly sensitive broad band mass spectrometer consists of a broad band selector of a low energy level beam of negative ions to be examined; a molecular disintegrator and charge changer which receives the negative ions and produces a beam of high-energy multiply charged positive ions free of molecules; and a broad band high-energy, continuously-operable isochronous time-of-flight mass spectrometer which receives the output from the molecular disintegrator. The disintegrator destroys molecules that would obscure the measurement of atomic species. Both selector and spectrometer preferably are electrostatic to avoid mass discrimination and maintain the broad band capability. The use of an isochronous time-of-flight mass spectrometer permits continuous operation which increases sensitivity. The ion selector may be of a magnetic type if a somewhat narrower band of masses is acceptable.
    Type: Grant
    Filed: February 11, 1982
    Date of Patent: December 18, 1984
    Assignee: The Innovations Foundation of the University of Toronto
    Inventors: Albert E. Litherland, Linas R. Kilius, Emil L. Hallin