Apparatus and method for rapid detection of explosives residue from the deflagration signature thereof

• US 5,912,466 A
• Filed: 06/10/1997
• Issued: 06/15/1999
• Est. Priority Date: 05/18/1995
• Status: Expired due to Fees

• Current Assignee: Los Alamos National Security LLC (Government of the United States of America)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Funsten, Herbert O., McComas, David J.
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): Jiron, Darren M.
• Application Number:
  US08/872,497
• Time in Patent Office: 735 Days
• Field of Search: 250/337, 250/372, 250/554, 356/36, 356/311, 356/312, 356/315
• US Class Current: 250/372
• CPC Class Codes: G01N 1/2208 with impactors
• CPC Class Codes: G01N 1/4022 by thermal techniques; Phase changes
• CPC Class Codes: G01N 2001/007 Devices specially adapted for forensic samples, e.g. tamper-proofing, sample tracking
• CPC Class Codes: G01N 2001/022 sampling for security purposes, e.g. contraband, warfare agents
• CPC Class Codes: G01N 2001/028 Sampling from a surface, swabbing, vaporising

Abstract

Apparatus and method for rapid detection of explosives residue from the deflagration signature thereof. A property inherent to most explosives is their stickiness, resulting in a strong tendency of explosive particulate to contaminate the environment of a bulk explosive. An apparatus for collection of residue particulate, burning the collected particulate, and measurement of the ultraviolet emission produced thereby, is described. The present invention can be utilized for real-time screening of personnel, cars, packages, suspected devices, etc., and provides an inexpensive, portable, and noninvasive means for detecting explosives.

Claims

1. An apparatus for determining the presence of particulate from explosive materials, which comprises in combination:

a heated surface for receiving the particulate maintained above the deflagration temperature of the particulate, wherein an ultraviolet signature is emitted from the deflagration of particulate thereon; and

an ultraviolet photodetector disposed such that the emitted ultraviolet signature is detected.

2. The apparatus for determining the presence of particulate from explosive materials as described in claim 1, further comprising means for collecting the particulate.

3. The apparatus for determining the presence of particulate from explosive materials as described in claim 2, wherein said means for collecting the particulate comprises means for entraining the particulate in a stream of air, and means for directing the stream of air containing the particulate over said heated surface such that a portion of the particulate impinge thereon.

4. The apparatus for determining the presence of particulate from explosive materials as described in claim 3, further comprising an enclosure containing said heated surface and said ultraviolet photodetector, wherein said means for entraining the particulate to be investigated in a stream of air, and said means for directing the stream of air containing the particulate over said surface comprise a vacuum pump for evacuating said enclosure, and tubing means having a first open end located in the vicinity of the particulate to be sampled and a second open end attached to said enclosure in the vicinity of said heated surface.

5. The apparatus for determining the presence of particulate from explosive materials as described in claim 1, wherein an infrared and visible light filter is employed to block substantially all light other than ultraviolet light from reaching said ultraviolet photodetector.

6. A method for determining the presence of particulate from explosive materials, which comprises the steps of:

depositing particulate on a surface heated to above the deflagration temperature of the particulate, wherein an ultraviolet signature is emitted from the deflagration of the particulate; and

detecting the emitted ultraviolet signature.

7. The method for determining the presence of particulate from explosive materials as described in claim 6, wherein infrared and visible light are substantially not detected.

8. An apparatus for determining the presence of particulate from explosive materials, which comprises in combination:

means for heating the particulate to above the deflagration temperature thereof without direct excitation from flames or plasmas, wherein an ultraviolet signature is emitted from the deflagration of the particulate; and

an ultraviolet photodetector disposed such that the emitted ultraviolet signature is detected.

9. The apparatus for determining the presence of particulate from explosive materials as described in claim 8, wherein an infrared and visible light filter is employed to block substantially all light other than ultraviolet light from reaching said ultraviolet photodetector.

10. A method for determining the presence of particulate from explosive materials, which comprises the steps of:

heating the particulate to above the deflagration temperature thereof without direct excitation from flames or plasmas, wherein an ultraviolet signature is emitted from the deflagration of the particulate; and

detecting the emitted ultraviolet signature.

11. The method for determining the presence of particulate from explosive materials as described in claim 10, wherein infrared and visible light are substantially not detected.