Real time explosive detection system

• US 20040124376A1
• Filed: 12/27/2002
• Published: 07/01/2004
• Est. Priority Date: 12/27/2002
• Status: Abandoned Application

• Current Assignee: Canberra Auila Incorporated
• Original Assignee: Canberra Auila Incorporated
• Inventors: Nadezdinskii, Alexander Ivanovich, Ershov, Oleg Valentinovich, Berezin, Andrei Georgievich, Kadner, Steven P.
• Application Number:
  US10/330,631
• Publication Number:
  US 20040124376A1
• Time in Patent Office: Days
• US Class Current: 250/554
• CPC Class Codes: G01J 3/42 Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry beam switching arrangements G01J3/08
• CPC Class Codes: G01N 1/2273 Atmospheric sampling
• CPC Class Codes: G01N 2001/024 passengers or luggage
• CPC Class Codes: G01N 2021/399 Diode laser
• CPC Class Codes: G01N 21/0332 with temperature control control of temperature G05D23/00; cryostats F17C3/08
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/39 using tunable lasers

Abstract

A system and an apparatus for detecting explosive in real time is provided for. The apparatus involves a chamber in which items pass through or people walk through for detecting said explosive particles in real time. The explosive particles from either the people or items will be deposited into a cell by an influx of air flow from the chamber flowing to the cell. The cell includes a heating device and an optical scheme. The cell is heated to a predetermined temperature in which the explosive particles are divided into small molecular components that can be detected. The optical scheme detects the smaller molecules. The computer system controls the apparatus and analyzes the data gathered.

Claims

1. An apparatus for detecting explosive particles in real time comprising:

a detecting chamber wherein items pass through for detecting said explosive particles in real time;

a cell coupled with an optical scheme wherein said optical scheme detects absorption bands of molecules present in said cell;

an air flow from said detection chamber into said cell wherein explosive particles deposit into said cell for detection; and

a processor coupled to said optical scheme to interpret said absorption bands.

2. The apparatus as recited in claim 1 wherein said explosive particles detector further comprises a heater couples with said cell wherein explosive particles are divided into smaller molecular components to be characterized and identifies.

3. The apparatus as recited in claim 1 wherein said optical scheme further comprises:

a diode laser for emitting radiation at a maximum absorption band of said explosive particles wherein said radiation is tunable by adjusting the temperature of said diode laser; and

a single source fiber coupling to said diode laser for narrowing wavelength range of said radiation wherein said remote gas molecule detector does not require an optical filter.

4. The apparatus as recited in claim 1 wherein said optical scheme further comprises:

a first connection for a first current into the diode laser; and

a second connection for a second current adjusting the temperature of the diode laser.

5. The apparatus as recited in claim 3 wherein said second current is tunable for a maximum absorption band of particle.

6. The apparatus as recited in claim 1 wherein said optical scheme further comprises:

an optical splitter receiving the emitted radiation and producing a first and second optical channels;

a first detector detecting the presence of said explosive from the first optical channel; and

a second detector for reference from the second optical channel.

7. The apparatus as recited in claim 6 wherein said first detector detects the presence of explosive particles.

8. The apparatus as recited in claim 1 wherein a person at a time passes through a second detection chamber for detecting said explosive particles in real time.

10. The apparatus as recited in claim 1 wherein said detecting chamber couples with an air blower for directing air into said cell wherein maximum explosive particles deposits in said cell.

11. The apparatus as recited in claim 1 wherein said detecting chamber couples with a marker to identify item when said item was detected to contain explosive particles for further investigation.

12. The apparatus as recited in claim 1 wherein said cell further couples with an air vacuum for directing air from said detecting chamber into said cell wherein maximum explosive particles deposits in said cell.

13. The apparatus as recited in claim 6 wherein said first optical channel is capable of passing twice through said cell to detect said particles, whereby the absorption of said particles is amplified.

14. A computer system for controlling a real time explosive particles detector, said computer system comprising:

a microprocessor for running software wherein the software analyzes the data from photodetectors and controls said explosive particles detector;

an explosive particles detector controller for transforming data between said explosive particles detector and the computer system; and

a storage device for storing predetermined diode laser pulsed current and analyzed data.

15. A computer system as recited in claim 14 wherein said explosive particles detector further comprises:

an analog to digital converter for sampling inputs into digitized data for storage in said computer system wherein said digitized data will be analyzed according to an absorption band of said explosive particles; and

a digital to analog converter for converting stored data into continuous data, wherein the continuous data couples to an input of said explosive particles detector.

16. A explosive particles detector system with an explosive particles detector, said system comprising:

a explosive particles detector wherein results of detection is in real time;

a computer system for running a software wherein the software analyzes the data from photodetectors and controls said explosive particles detector; and

an interface connecting said computer system and said explosive particles detector.

17. A explosive particles detector system as recited in claim 16, wherein said interface comprises:

a diode laser supply transforming continuous diode laser current for explosive particles detector;

a resistance-voltage transformer providing good thermal contact with diode laser;

a peltier current supply providing power amplifier for pump current; and

photodetector transformer/amplifier unit for interfacing between a photodetector and an explosive particles controller.

18. The computer program product in a computer readable medium for an explosive particles detector comprising:

instructions for signal processing for generating the diode laser current pulses;

instructions for stabilizing diode laser temperature wherein diode laser radiation is tunable by adjusting the temperature of said diode laser; and

instructions for calculating explosive particles concentration detected by said explosive particles detector.

19. The computer program product recited in claim 18, where in said instructions for signal processing further comprises:

first instructions for setting pattern of current pulses;

second instructions for storing pattern in a buffer memory; and

third instructions for applying pattern to a digital to analog converter.

20. The computer program product recited in claim 18, wherein said instructions for temperature stablilization further comprises:

first instructions for setting initial diode laser temperature by thermistor;

second instructions for switching to line stabilization position;

third instructions for receiving signal from reference signal;

fourth instructions for calculating the line position of the reference signal;

fifth instructions for determining peltier current from the line position; and

sixth instructions for applying peltier current to a digital to analog converter.

21. The computer program product recited in claim 18, wherein said instructions for calculating gas molecule concentration further comprises:

first instructions for receiving sampled data from said explosive particles detector;

second instructions for checking and comparing said sampled data with predetermined fourier transform featuring absorption of said explosive particles and absorption a predetermined molecule content in a reference cell;

third instructions for producing distinctive channels;

fourth instructions for separating the channel containing the detected explosive particles according to discrete pulses of a diode laser current;

fifth instructions for generating an odd and even arrays from said explosive particles channel;

sixth instructions for subtracting zero signal from odd array;

seventh instructions for subtracting zero signal from even array;

eighth instructions for calculating the logarithm of even over odd ratio; and

ninth instruction for mutual ortogonalization of said gas molecule to be detected and content in the reference cell thereby, the concentration of explosive particles is calculated.