Science Applications International Corporation

Other

Eai Corporation

Timothy Paul Karpetsky

John C Berends, Jr

Ross Clark Willoughby

Edward William Sheehan

Daniel Lee Schwarz

Stephen Charles Hope

R William Mengel

John Henry Ludwig

An extremely dilute mixture of a liquid in a flowing fluid stream is prepared by forming tiny droplets of the liquid and injecting the droplets individually into the flowing stream. The rate at which liquid is added to the flowing stream is determined by the number of droplet forming units that are provided and upon the frequency with which the units are activated, allowing a precise digital control of the concentration of the liquid in the flowing fluid stream.

Method and means for precision mixing

A soft chemical ionization source can be small, require low power, reliably produce different ions depending on the operating conditions and configuration, and produce ions that ionize many sample chemicals in different phases in air, or solutions, or on surfaces. In one embodiment, an ionization source is comprised of a housing having a center post extending therefrom, a plurality of needles extending from the housing, and a counterelectrode extending around the housing. The plurality of needles and the counterelectrode are each coupled to an electrical supply. The center post and the plurality of needles extend through the counterelectrode. A voltage applied to the plurality of needles and the counterelectrode forms a gas discharge. By changing the dimensional or electrical characteristics of the ionization source elements, singularly, or relative to other sources in an array, the types, ratios among, and quantities of reagent ions can be changed and controlled.

Soft chemical ionization source

Ions carried in a flowing gas stream are transferred to another gas stream of different composition or purity through an ion selective aperture communicating between the gas streams. The ion selective aperture is formed of a central layer which has an electrically conductive layer on each of its surfaces. One or more open channels extend through the central layer and surface layers allowing physical movement of ions therethrough under the urging and influence of an electric field created by imposing a voltage differential between the conductive surface layers of the ion selective aperture. The gas flow rates of the different gas streams may be independently varied to allow adjustment of ion concentration and flow rate to meet the needs of the ion destination. This device can control sample ion introduction into gas-phase ion detectors, such as ion mobility analyzers, differential mobility analyzers, mass spectrometers, and combinations thereof.

Ion transfer device

A system for the stand-off detection of trace amounts of analyte materials such as explosives, chemical warfare agents, toxic industrial chemicals, and the like includes an ion source that is operably connected to an ion collection means and to a sensor. The ion source employs a first gas that is passed through an electrical discharge to produce metastable gas molecules as well as charged particles of various kinds. Ions and other charged particles are removed from the first gas which is then reacted with a second gas having a lower ionization potential to obtain reactant ions of relatively uniform energy. The reactant ions are focused and accelerated into a beam that is directed upon a surface, such as luggage or clothing that is being interrogated, to produce analyte ions which are collected and passed into the sensor that is preferably a differential mobility spectrometer.

Method and device for non-contact sampling and detection

A system for the non-contact detection of analyte chemicals, including explosives, chemical warfare agents and the like, employs a non-equilibrium plasma that is maintained at a temperature sufficiently low so as to avoid thermal damage to a surface, such as clothing or skin, that is being examined to thereby produce analyte ions and other charged particles. The ions are collected and passed into a sensor for detection and identification.

Non-contact detector system with plasma ion source

An improved ion source and means for collecting and focusing dispersed gas-phase ions from a remote reagent chemical ionization source (R2CIS) at atmospheric or intermediate pressure is described. The R2CIS is under electronic control and can produce positive, negative, or positive and negative reagent ions simultaneously. This remote source of reagent ions is separated from a low-field sample ionization region by a stratified array of elements, each element populated with a plurality of openings, wherein DC potentials are applied to each element necessary for transferring reagent ions from the R2CIS into the low-field sample ionization region where the reagent ions react with neutral and/or ionic sample forming sample ionic species. The resulting sample ionic species are then introduced into a mass spectrometer, ion mobility spectrometer or other sensor capable of detecting the sample ions. Embodiments of this invention are methods and devices for improving sensitivity of mass spectrometry when gas and liquid chromatographic separation techniques are coupled to atmospheric and intermediate pressure photo-ionization, chemical ionization, and thermospray ionization sources; and improving the sensitivity of chemical detectors or probes.

Remote reagent ion generator

A char containing less than 5% volatile matter is produced by pryolyzing shredded scrap vehicle tires and other rubber scrap material in an externally heated retort until the rubber is completely decomposed and until the temperature of the gases produced by the pyrolysis process reaches at least 500&#xb0; C. The char is then subjected to resonance disintegration of an intensity sufficient to produce an unltrafine, particulate carbon product. In a preferred embodiment, essentially 100% of the individual carbon product particles are smaller than about 8 microns, and that product displays a dispersion coefficient in rubber of greater than 87%. The surface properties of the carbon product particles may be further modified by reacting or coating the carbon with chemical compounds or coating agents during or immediately after the resonance disintegration to tailor the properties of the carbon product to its use.

Growing community of inventors

Towson, MD, United States of America

Timothy Paul Karpetsky