Patents by Inventor Richard L. Freeman
Richard L. Freeman 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).
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Publication number: 20040178151Abstract: A material separator includes a chamber and electrode(s) to create a radially oriented electric field in the chamber. Coils are provided to generate a magnetic field in the chamber. The separator further includes a launcher to propagate a high-frequency electromagnetic wave into the chamber to convert the material into a multi-species plasma. With the crossed electric and magnetic fields, low mass ions in the multi-species plasma are placed on small orbit trajectories and exit through the end of the chamber while high mass ions are placed on large orbit trajectories for capture at the wall of the chamber.Type: ApplicationFiled: March 10, 2003Publication date: September 16, 2004Inventors: Richard L. Freeman, Robert L. Miller, John Gilleland, Tihiro Ohkawa
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Patent number: 6787044Abstract: A material separator includes a chamber and electrode(s) to create a radially oriented electric field in the chamber. Coils are provided to generate a magnetic field in the chamber. The separator further includes a launcher to propagate a high-frequency electromagnetic wave into the chamber to convert the material into a multi-species plasma. With the crossed electric and magnetic fields, low mass ions in the multi-species plasma are placed on small orbit trajectories and exit through the end of the chamber while high mass ions are placed on large orbit trajectories for capture at the wall of the chamber.Type: GrantFiled: March 10, 2003Date of Patent: September 7, 2004Assignee: Archimedes Technology Group, Inc.Inventors: Richard L. Freeman, Robert L. Miller, John Gilleland, Tihiro Ohkawa
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Publication number: 20040077916Abstract: A method and system for increasing the waste loading of vitrified nuclear waste includes a plasma mass filter and a heating apparatus. The plasma mass filter is used first to collect radioactive particles from a multi-species plasma. The radioactive particles are then placed, together with a frit, in crucibles. The crucibles are then induction heated to fuse the radioactive elements with the frit to form a melted mixture which is then cooled to form vitrified waste having relatively high waste loading.Type: ApplicationFiled: October 16, 2002Publication date: April 22, 2004Inventors: John Gilleland, Richard L. Freeman, Stephen F. Agnew
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Patent number: 6398920Abstract: A filter and a method for separating ions in a partially ionized plasma according to their mass includes a chamber with crossed electric and magnetic fields established therein. A feed, including metal atoms having ionization potentials in a low range, and gas atoms having an ionization potential in a high range, is introduced into the chamber. An electron temperature below the low range is generated to partially ionize the feed by dissociating the metal atoms from the gas atoms, and by ionizing the metal atoms into light and heavy ions according to their mass to charge ratio. The light and heavy ions are then influenced by the crossed electric and magnetic fields to separate the light ions from the heavy ions.Type: GrantFiled: February 21, 2001Date of Patent: June 4, 2002Assignee: Archimedes Technology Group, Inc.Inventors: Tihiro Ohkawa, Robert L. Miller, Sergei Putvinski, Richard L. Freeman
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Patent number: 6386374Abstract: A multi-mass filter for separating particles of a multi-species plasma includes a chamber, which defines an axis. A radial electric field is crossed with a magnetic field (E×B) to move the particles of different mass (M1, M2 and M3) on respective trajectories into respective first, second and third regions. Specifically, particles M1 are confined in the first region, while both particles M3 and M2 are ejected from the first region into the second region and only the particles M3 are ejected from the second region into the third region.Type: GrantFiled: May 17, 2001Date of Patent: May 14, 2002Assignee: Archimedes Technology Group, Inc.Inventors: Robert L. Miller, Tihiro Ohkawa, Richard L. Freeman
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Patent number: 6356025Abstract: A device for generating a plasma includes an enclosed chamber and an antenna positioned adjacent the wall of the chamber. A ceramic shield is mounted on the wall, with the antenna located between the wall and the ceramic shield. There is also a barrier that is mounted on the wall with the ceramic shield being between the barrier and the antenna element. An alternating voltage source is provided to energize the antenna element to generate a plasma in the chamber. In operation, the ceramic shield isolates the antenna from the plasma in the chamber, and the barrier prevents the deposition of material components from the plasma on the ceramic shield.Type: GrantFiled: October 3, 2000Date of Patent: March 12, 2002Assignee: Archimedes Technology Group, Inc.Inventors: Richard L. Freeman, Robert L. Miller
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Publication number: 20020020657Abstract: A multi-mass filter for separating particles of a multi-species plasma includes a chamber, which defines an axis. A radial electric field is crossed with a magnetic field (E×B) to move the particles of different mass (M1, M2 and M3) on respective trajectories into respective first, second and third regions. Specifically, particles M1 are confined in the first region, while both particles M3 and M2 are ejected from the first region into the second region and only the particles M3 are ejected from the second region into the third region.Type: ApplicationFiled: May 17, 2001Publication date: February 21, 2002Inventors: Robert L. Miller, Tihiro Ohkawa, Richard L. Freeman
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Patent number: 6304036Abstract: A system and method for initiating and maintaining a plasma in a chamber, in accordance with the helicon dispersion relation, requires an antenna for radiating RF energy into the chamber. An interferometer, or some similar device, is used in the system to monitor the plasma density level in the chamber, as the plasma is being produced. The plasma density level is then used to control the variable characteristics of the RF energy in accordance with the helicon dispersion relation.Type: GrantFiled: August 8, 2000Date of Patent: October 16, 2001Assignee: Archimedes Technology Group, Inc.Inventors: Richard L. Freeman, Robert L. Miller
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Patent number: 6293406Abstract: A multi-mass filter for separating particles according to their mass-charge ratio includes a chamber for receiving a multi-species plasma that includes particles therein having different mass-charge ratios (with M1<M2<M3). Inside the chamber, which defines an axis, a radial electric field is crossed with a magnetic field (E≦B) to move the particles (M1, M2 and M3) on respective trajectories into respective first, second and third regions. For one embodiment, the filter is configured so that az2Bz is held constant in the expression for cut-off mass, Mcz=eaz2Bz2/(8Vctr). For this embodiment, only the heavier particles M3 are ejected into the third region (M3>Mc3) and only the intermediate particles M2 are ejected into the second region (M2>Mc2). In another embodiment, the radial electrical field is increased outwardly from the axis to a radial distance a2 (r2) at a first rate.Type: GrantFiled: August 21, 2000Date of Patent: September 25, 2001Assignee: Archimedes Technology Group, Inc.Inventors: Robert L. Miller, Tihiro Ohkawa, Richard L. Freeman
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Patent number: 6251282Abstract: A plasma mass filter using a helical magnetic field for separating low-mass particles from high-mass particles in a multi-species plasma includes a cylindrical outer wall located at a distance “a” from a longitudinal axis. Also included is a coaxial cylindrical inner wall positioned to establish a plasma chamber between the inner and outer walls. The magnetic field is generated in this chamber with an axial component (Bz) and an azimuthal component (B&thgr;), which interact together with an electric field to create crossed magnetic and electric fields. The electric field has a positive potential, Vctr, on the inner wall and a zero potential on the outer wall.Type: GrantFiled: December 8, 1999Date of Patent: June 26, 2001Assignee: Archimedes Technology Group, Inc.Inventors: Sergei Putvinski, Tihiro Ohkawa, Richard L. Freeman
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Patent number: 4564807Abstract: A method for judging whether a group of semiconductor devices have sufficiently short carrier lifetimes to make them suitable for use in high speed electronic circuitry. A determination is made as to the satisfactory carrier lifetime for a pn junction in the devices. A capacitance value representative of the pn junction, when reverse biased, is also determined. The pn junction is placed in series with an inductor sized so that the resonant frequency of the inductor and the pn junction, when reversely biased, is substantially equal to the reciprocal of the carrier lifetime. An oscillating voltage is applied to the series combination of the junction and the inductor, the voltage having a fundamental frequency near but above the resonant frequency and an amplitude greater than a predetermined level which is in the range of 3-5 volts. Finally, the device under test is rejected should an output taken across the pn junction show a substantial frequency component below the fundamental frequency.Type: GrantFiled: March 27, 1984Date of Patent: January 14, 1986Assignee: GA Technologies Inc.Inventors: Hiroyuki Ikezi, Richard L. Freeman