Patents by Inventor Ka-Ngo Leung

Ka-Ngo Leung 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).

  • Publication number: 20240032182
    Abstract: The present disclosure provides a D?7Li neutron generator system and methods for producing a large amount of 225Ac. High flux 10 and 13 MeV neutrons generated by the (D?7Li) reaction are used to irradiate 226Ra forming 225Ra/225Ac via the 226Ra(n,2n)225Ra reaction. The generator consists of three main components: (1) a surface-production type negative ion source; (2) an extraction and acceleration column; and (3) a beam target Lithium electrode to irradiate 226Ra resulting in the formation of 225Ac. The methods enable the negative deuterium ion-base compact neutron generation system to generate reliably high yield of neutron flux in the absence of back-streaming electrons for producing 225Ac in large quantities but with a very small percentage of 227Ac (˜1%).
    Type: Application
    Filed: December 6, 2022
    Publication date: January 25, 2024
    Inventors: Maurizio Martellini, Giuseppe Gherardi, Lidia Falzone, Cristina Costamagna, Ka-Ngo Leung, James Kin-Bon Leung
  • Patent number: 8971473
    Abstract: An apparatus for the generation of neutron/gamma rays is described including a chamber which defines an ion source, said apparatus including an RF antenna positioned outside of or within the chamber. Positioned within the chamber is a target material. One or more sets of confining magnets are also provided to create a cross B magnetic field directly above the target. To generate neutrons/gamma rays, the appropriate source gas is first introduced into the chamber, the RF antenna energized and a plasma formed. A series of high voltage pulses are then applied to the target. A plasma sheath, which serves as an accelerating gap, is formed upon application of the high voltage pulse to the target. Depending upon the selected combination of source gas and target material, either neutrons or gamma rays are generated, which may be used for cargo inspection, and the like.
    Type: Grant
    Filed: June 9, 2009
    Date of Patent: March 3, 2015
    Assignees: Sandia Corporation, Lawrence Berkeley National Laboratory
    Inventors: Ka-Ngo Leung, Arlyn Antolak
  • Patent number: 8279993
    Abstract: A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360° and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.
    Type: Grant
    Filed: August 14, 2009
    Date of Patent: October 2, 2012
    Assignee: The Regents of the University of California
    Inventors: Ka-Ngo Leung, Tak Pui Lou, William A. Barletta
  • Publication number: 20120213319
    Abstract: An apparatus and method for fast pulsing of a neutron generator is described in which a series of electrodes are used to first extract deuterium or tritium ions from a plasma contained within an ion source, and then either accelerate or stop the flow of ions to the source, depending upon the voltage potential applied to the downstream electrodes. In one embodiment, the extraction/gating system comprises 3 electrodes, a first extraction electrode which is maintained at the same positive potential as the ion sources, a second electrode maintained at a lower potential to extract ions from the source, and a third electrode which depending on the operational mode is maintained either at the same potential as the second electrode (for beam passage) or at a potential higher than that of the first electrode (for beam blockage).
    Type: Application
    Filed: August 13, 2010
    Publication date: August 23, 2012
    Applicant: The Regents of the University of California
    Inventors: Joe Kwan, Qing Ji, Ka-Ngo Leung
  • Publication number: 20110096885
    Abstract: An apparatus for the generation of neutron/gamma rays is described including a chamber which defines an ion source, said apparatus including an RF antenna positioned outside of or within the chamber. Positioned within the chamber is a target material. One or more sets of confining magnets are also provided to create a cross B magnetic field directly above the target. To generate neutrons/gamma rays, the appropriate source gas is first introduced into the chamber, the RF antenna energized and a plasma formed. A series of high voltage pulses are then applied to the target. A plasma sheath, which serves as an accelerating gap, is formed upon application of the high voltage pulse to the target. Depending upon the selected combination of source gas and target material, either neutrons or gamma rays are generated, which may be used for cargo inspection, and the like.
    Type: Application
    Filed: June 9, 2009
    Publication date: April 28, 2011
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Ka-Ngo Leung, Arlyn Antolak
  • Publication number: 20100172458
    Abstract: A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360° and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.
    Type: Application
    Filed: August 14, 2009
    Publication date: July 8, 2010
    Applicant: REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Ka-Ngo Leung, Tak-Pui Lou, William A. Barletta
  • Publication number: 20100025573
    Abstract: A fast nuclear particle generator is described, useful for highly penetrating particle beam inspection equipment, that is capable of generating pulses of 5 ns or less, which pulses may comprise neutrons of various energies, gammas of various energies, or a mixture of neutron and gammas of various energies. The nuclear particle generator includes means for decelerating an incident swept beam so that nuclear particles are generated only during that small time interval that a beam strikes a target. This eliminates spurious background nuclear particle generation, and decreases beam dump cooling requirements.
    Type: Application
    Filed: December 14, 2007
    Publication date: February 4, 2010
    Applicant: The Regents of the University of California
    Inventors: Sami K. Hahto, Ka-Ngo Leung, Taneli Ville Matias Kalvas
  • Patent number: 7639770
    Abstract: A cylindrical neutron generator is formed with a coaxial RF-driven plasma ion source and target. A deuterium (or deuterium and tritium) plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical neutron generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which contain many slots. The plasma generator emanates ions radially over 360° and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired. The plasma generator may be in the center and the neutron target on the outside, or the plasma generator may be on the outside and the target on the inside. In a nested configuration, several concentric targets and plasma generating regions are nested to increase the neutron flux.
    Type: Grant
    Filed: April 22, 2008
    Date of Patent: December 29, 2009
    Assignee: The Regents of the University of California
    Inventor: Ka-Ngo Leung
  • Patent number: 7609815
    Abstract: Techniques for controllably directing beamlets to a target substrate are disclosed. The beamlets may be either positive ions or electrons. It has been shown that beamlets may be produced with a diameter of 1 ?m, with inter-aperture spacings of 12 ?m. An array of such beamlets, may be used for maskless lithography. By step-wise movement of the beamlets relative to the target substrate, individual devices may be directly e-beam written. Ion beams may be directly written as well. Due to the high brightness of the beamlets from extraction from a multicusp source, exposure times for lithographic exposure are thought to be minimized. Alternatively, the beamlets may be electrons striking a high Z material for X-ray production, thereafter collimated to provide patterned X-ray exposures such as those used in CAT scans. Such a device may be used for remote detection of explosives.
    Type: Grant
    Filed: June 1, 2007
    Date of Patent: October 27, 2009
    Assignee: The Regents of the University of California
    Inventors: Ka-Ngo Leung, Qing Ji, William A. Barletta, Ximan Jiang, Lili Ji
  • Publication number: 20090262881
    Abstract: A cylindrical neutron generator is formed with a coaxial RF-driven plasma ion source and target. A deuterium (or deuterium and tritium) plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical neutron generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which contain many slots. The plasma generator emanates ions radially over 360° and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired. The plasma generator may be in the center and the neutron target on the outside, or the plasma generator may be on the outside and the target on the inside. In a nested configuration, several concentric targets and plasma generating regions are nested to increase the neutron flux.
    Type: Application
    Filed: April 22, 2008
    Publication date: October 22, 2009
    Inventor: Ka-Ngo Leung
  • Patent number: 7596197
    Abstract: A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360° and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.
    Type: Grant
    Filed: August 7, 2006
    Date of Patent: September 29, 2009
    Assignee: The Regents of the University of California
    Inventors: Ka-Ngo Leung, Tak Pui Lou, William A. Barletta
  • Publication number: 20090230314
    Abstract: A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360° and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.
    Type: Application
    Filed: August 7, 2006
    Publication date: September 17, 2009
    Inventors: Ka-Ngo Leung, Tak Pui Lou, William A. Barletta
  • Patent number: 7362842
    Abstract: A cylindrical neutron generator is formed with a coaxial RF-driven plasma ion source and target. A deuterium (or deuterium and tritium) plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical neutron generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which contain many slots. The plasma generator emanates ions radially over 360° and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired. The plasma generator may be in the center and the neutron target on the outside, or the plasma generator may be on the outside and the target on the inside. In a nested configuration, several concentric targets and plasma generating regions are nested to increase the neutron flux.
    Type: Grant
    Filed: April 19, 2005
    Date of Patent: April 22, 2008
    Assignee: Regents of the University of California
    Inventor: Ka-Ngo Leung
  • Publication number: 20080080659
    Abstract: A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.
    Type: Application
    Filed: December 4, 2007
    Publication date: April 3, 2008
    Inventors: Ka-Ngo Leung, Tak Lou, Jani Reijonen
  • Patent number: 7342988
    Abstract: A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.
    Type: Grant
    Filed: February 6, 2003
    Date of Patent: March 11, 2008
    Assignee: The Regents of the University of California
    Inventors: Ka-Ngo Leung, Tak Pui Lou, Jani Reijonen
  • Publication number: 20080049888
    Abstract: Techniques for controllably directing beamlets to a target substrate are disclosed. The beamlets may be either positive ions or electrons. It has been shown that beamlets may be produced with a diameter of 1 ?m, with inter-aperture spacings of 12 ?m. An array of such beamlets, may be used for maskless lithography. By step-wise movement of the beamlets relative to the target substrate, individual devices may be directly e-beam written. Ion beams may be directly written as well. Due to the high brightness of the beamlets from extraction from a multicusp source, exposure times for lithographic exposure are thought to be minimized. Alternatively, the beamlets may be electrons striking a high Z material for X-ray production, thereafter collimated to provide patterned X-ray exposures such as those used in CAT scans. Such a device may be used for remote detection of explosives.
    Type: Application
    Filed: June 1, 2007
    Publication date: February 28, 2008
    Inventors: Ka-Ngo Leung, Qing Ji, William Barletta, Ximan Jiang, Lili Ji
  • Patent number: 7298091
    Abstract: A compact matching network couples an RF power supply to an RF antenna in a plasma generator. The simple and compact impedance matching network matches the plasma load to the impedance of a coaxial transmission line and the output impedance of an RF amplifier at radio frequencies. The matching network is formed of a resonantly tuned circuit formed of a variable capacitor and an inductor in a series resonance configuration, and a ferrite core transformer coupled to the resonantly tuned circuit. This matching network is compact enough to fit in existing compact focused ion beam systems.
    Type: Grant
    Filed: February 1, 2002
    Date of Patent: November 20, 2007
    Assignee: The Regents of the University of California
    Inventors: Daniel S. Pickard, Ka-Ngo Leung
  • Publication number: 20070242790
    Abstract: A neutron generator comprising a boron-10 bearing target and a low-energy accelerator, wherein said low-energy accelerator emits a plurality of particles which bombard said boron-10 bearing target to cause a 10B(d,n)11C reaction which in turn produces a plurality of neutrons having an energy value greater than about 2 MeV and less than about 8 MeV.
    Type: Application
    Filed: March 30, 2007
    Publication date: October 18, 2007
    Applicant: The Regents of the University of California
    Inventors: Tak Lou, Ka-Ngo Leung
  • Patent number: 7176469
    Abstract: A radio frequency (RF) driven plasma ion source has an external RF antenna, i.e. the RF antenna is positioned outside the plasma generating chamber rather than inside. The RF antenna is typically formed of a small diameter metal tube coated with an insulator. An external RF antenna assembly is used to mount the external RF antenna to the ion source. The RF antenna tubing is wound around the external RF antenna assembly to form a coil. The external RF antenna assembly is formed of a material, e.g. quartz, which is essentially transparent to the RF waves. The external RF antenna assembly is attached to and forms a part of the plasma source chamber so that the RF waves emitted by the RF antenna enter into the inside of the plasma chamber and ionize a gas contained therein. The plasma ion source is typically a multi-cusp ion source. A converter can be included in the ion source to produce negative ions.
    Type: Grant
    Filed: September 6, 2003
    Date of Patent: February 13, 2007
    Assignee: The Regents of the University of California
    Inventors: Ka-Ngo Leung, Sami K. Hahto, Sari T. Hahto
  • Patent number: 7139349
    Abstract: A spherical neutron generator is formed with a small spherical target and a spherical shell RF-driven plasma ion source surrounding the target. A deuterium (or deuterium and tritium) ion plasma is produced by RF excitation in the plasma ion source using an RF antenna. The plasma generation region is a spherical shell between an outer chamber and an inner extraction electrode. A spherical neutron generating target is at the center of the chamber and is biased negatively with respect to the extraction electrode which contains many holes. Ions passing through the holes in the extraction electrode are focused onto the target which produces neutrons by D-D or D-T reactions.
    Type: Grant
    Filed: March 18, 2002
    Date of Patent: November 21, 2006
    Assignee: The Regents of the University of California
    Inventor: Ka-Ngo Leung