Patents by Inventor Jerry T. Dowell

Jerry T. Dowell 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: 7397026
    Abstract: The present invention relates to, inter alia, methods and apparatuses for electron transfer dissociation (ETD) that vary the internal energy of precursor ions for ETD. The methods and apparatuses are particularly useful in mass spectrometry.
    Type: Grant
    Filed: April 30, 2007
    Date of Patent: July 8, 2008
    Assignee: Agilent Technologies, inc.
    Inventor: Jerry T Dowell
  • Patent number: 7385189
    Abstract: The present invention provides an apparatus and method for use with a mass spectrometry system. The invention provides an ion source for providing radiative heating to an ionization region. The ion source includes a nanospray ionization device for producing ions and a conduit adjacent to the ionization device for receiving ions from the ionization device. The conduit includes a conductive material for providing indirect radiative heating to the ionization region. Direct radiative heating may also be provided using a heater in the conduit. The ion source may be used separately or in conjunction with the mass spectrometry system. When used in conjunction with a mass spectrometry system a detector may also be employed down stream from the device. A method for desolvating an analyte using the device is also disclosed.
    Type: Grant
    Filed: June 29, 2005
    Date of Patent: June 10, 2008
    Assignee: Agilent Technologies, Inc.
    Inventors: Paul C. Goodley, Timothy Herbert Joyce, Jerry T. Dowell
  • Patent number: 7385185
    Abstract: In a tandem mass spectrometer means are provided for molecular activation of ions prior to fragmentation. An embodiment of a tandem mass spectrometer comprises a first collision cell receiving analyte ions having an internal energy and a second collision cell situated downstream from the first collision cell wherein the first collision cell increases the internal energy of the analyte ions prior to entry of the ions into the second collision cell, the increase in internal energy imparted in the first collision cell alone being insufficient to fragment a substantial portion of the analyte ions. Another embodiment includes a collision cell with a heating device situated adjacent to the collision cell for controlling the temperature within the collision cell.
    Type: Grant
    Filed: December 20, 2005
    Date of Patent: June 10, 2008
    Assignee: Agilent Technologies, Inc.
    Inventors: Jerry T. Dowell, John Fjeldsted
  • Patent number: 6153880
    Abstract: A mass spectrometer method and apparatus improve resolution and sensitivity. A voltage supply is coupled to a mass filter for applying a radio frequency voltage and for operating at at least one selected frequency. An ion optical element such as an entrance lens is driven by a voltage supply that is phase coherent with the voltage applied to the mass filter. The ion beam is tailored so that the phase space relationship of the ions is more closely matched to the acceptance of the mass filter. The ions in the incoming beam are dynamically matched to the acceptance of the mass filter over each cycle of the voltage applied to the mass filter. The ion optical element may be a single entrance lens to which is applied only a single phase coherent voltage.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: November 28, 2000
    Assignee: Agilent Technologies, Inc.
    Inventors: Charles William Russ, IV, Jerry T. Dowell, Steven M. Fischer
  • Patent number: 6037587
    Abstract: A mass spectrometer having an ionization source containing a chemical ionization chamber, wherein the inner surfaces of the chamber are formed from molybdenum to reduce adsorption, degradation and decomposition of an analyte and to reduce adverse ion/surface reactions is disclosed. A method of reducing adsorption, degradation and decomposition of an analyte and reducing adverse ion/surface reactions in an ionization source containing a chemical ionization chamber of a mass spectrometer including the step of forming the inner surfaces of the chamber from molybdenum is also disclosed. The inner surfaces may formed from molybdenum by constructing the entire chamber or the inner surfaces of the chamber from molybdenum; by depositing, plating or coating molybdenum on the inner surfaces of the chamber; or by a combination thereof. Suitable forms of molybdenum include solid molybdenum, mixtures containing at least 10% by weight molybdenum, and reaction products containing molybdenum.
    Type: Grant
    Filed: October 17, 1997
    Date of Patent: March 14, 2000
    Assignee: Hewlett-Packard Company
    Inventors: Jerry T. Dowell, Jeffery S. Hollis, Charles W. Russ, IV
  • Patent number: 5734162
    Abstract: Selective trapping of ions from an external source into a quadrupole trap is accomplished by applying a parametric pump voltage to the quadrupole trap electrodes in such a phase as to extract energy from the ions, causing the ions to accumulate in the center of the trap. Pump voltage phase is controlled by the timing of the injection of ions into the trap relative to the absolute phase of the pump voltage. Optimum phasing results when the ion packet allowed into the trap through gating of the ion beam optics is sufficiently opposed by the field produced by the parametric pump voltage. The ions are also subjected to a normal RF trapping field.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: March 31, 1998
    Assignee: Hewlett Packard Company
    Inventor: Jerry T. Dowell
  • Patent number: 5331158
    Abstract: The apparatus and method of the present invention multiplexes or gates particle beams to provide continuous data collection useful in time-of-flight mass spectrometry. The multiple particle beams are gated or combined to achieve an overall 100% duty cycle. This allows continuous data collection, thereby realizing the full advantages of abundance sensitivity and mass resolution in time-of-flight mass spectrometry.
    Type: Grant
    Filed: December 7, 1992
    Date of Patent: July 19, 1994
    Assignee: Hewlett-Packard Company
    Inventor: Jerry T. Dowell