Chemiluminescent detection of explosives, narcotics, and other chemical substances
First Claim
1. A system for screening at least a portion of the surface of a baggage item for the presence thereon of a contraband substance, the system comprising:
- a. an infrared laser adapted to emit light;
b. an optical system adapted to deliver a beam of said light emitted from said infrared laser to illuminate an interrogation area of said surface, said illumination having sufficient intensity and duration to cause selective desorption of molecules of said contraband substance present within said interrogation area without substantially damaging said surface, and at least a portion of said molecules being thermally decomposed to produce NO2 molecules;
c. a collection system having at least one aperture and being adapted to collect at least a portion of said desorbed molecules through said aperture;
d. a reaction cell in communication with said collection system, said reaction cell having a reaction zone, an inlet for receiving in said reaction zone said molecules collected by said collection system; and
an outlet for release of said air, and said reaction cell containing an alkaline, aqueous luminol-containing solution;
e. a light detector for detecting light produced chemiluminescently by a chemical reaction between said luminol and said NO2 within said reaction cell, and for outputting an electrical signal indicative of the detection of said light; and
f. signal means for indicating the presence of said NO2 produced by the decomposition of said contraband substance, said signal means being operably connected to said light detector and responsive to the receipt of said electrical signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A compact scanning apparatus has an infrared laser adapted to emit light. The light is delivered as a beam by an optical system to illuminate an interrogation area on the surface of an object being scanned. Such illumination has sufficient intensity and duration to cause selective desorption of molecules of the contraband substance, which are present on the surface, without substantially damaging the surface. A collection system collects at least a portion of the desorbed molecules. At least a portion of the collected molecules is thermally decomposed to form NO2 and transferred to a reaction cell containing an aqueous, alkaline, luminol-containing solution. The NO2 reacts with the luminol to produce light by chemiluminescence. A light detector registers the presence of this light as indicative of the detection of the contraband substance, and activates a signaling device to provide an audible or visible alarm. The apparatus rapidly detects the presence of a wide variety of contraband substances in an accurate, reliable manner. It provides for automated screening, with the result that vagaries of human performance are virtually eliminated. False alarms are reduced and detection efficacy is increased. A traceable residue of the detected contraband is left on the article for use in forensic analysis.
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Citations
40 Claims
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1. A system for screening at least a portion of the surface of a baggage item for the presence thereon of a contraband substance, the system comprising:
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a. an infrared laser adapted to emit light; b. an optical system adapted to deliver a beam of said light emitted from said infrared laser to illuminate an interrogation area of said surface, said illumination having sufficient intensity and duration to cause selective desorption of molecules of said contraband substance present within said interrogation area without substantially damaging said surface, and at least a portion of said molecules being thermally decomposed to produce NO2 molecules; c. a collection system having at least one aperture and being adapted to collect at least a portion of said desorbed molecules through said aperture; d. a reaction cell in communication with said collection system, said reaction cell having a reaction zone, an inlet for receiving in said reaction zone said molecules collected by said collection system; and
an outlet for release of said air, and said reaction cell containing an alkaline, aqueous luminol-containing solution;e. a light detector for detecting light produced chemiluminescently by a chemical reaction between said luminol and said NO2 within said reaction cell, and for outputting an electrical signal indicative of the detection of said light; and f. signal means for indicating the presence of said NO2 produced by the decomposition of said contraband substance, said signal means being operably connected to said light detector and responsive to the receipt of said electrical signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. A method of scanning at least a portion of the surface of a baggage item for the presence thereon of at least one contraband substance, the method comprising the steps of:
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a. illuminating an interrogation area of said surface with infrared laser light to selectively desorb molecules of said contraband substance; b. thermally decomposing at least a portion of said desorbed molecules to form NO2; c. passing said NO2 into a reaction cell, said reaction cell having a reaction zone and comprising an aqueous, alkaline, luminol-containing solution; d. reacting said NO2 in said reaction cell with said luminol to produce light and e. detecting said light; and f. signaling the detection of said light to indicate the presence of said contraband substance on the surface of said baggage item. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40)
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Specification