Glow discharge and photoionizaiton source
View Patent ↗A detector that may contain a glow discharge ionizer and a photo-ionizer. The existence of both ionizers may increase the accuracy and number of chemical compounds that can be simultaneously monitored for chemical screening applications. The detector is particularly useful for screening explosives, chemical agents, and other illicit chemicals.
1. A detector system that detects a trace molecule from a sample, comprising:
a glow discharge ionizer that includes a first electrode, and a second electrode separated by a first ionization chamber, said glow discharge ionizer ionizes the sample;
a first photo-ionizer that ionizes the sample in said first ionization chamber; and,
a detector coupled to said first ionization chamber.
2. The system of claim 1 , further comprising a photocathode coupled to said first photo-ionizer.
3. The system of claim 2 , further comprising a lamp electrode coupled to said first photo-ionizer.
4. The system of claim 1 , further comprising a second photo-ionizer that ionizes the sample.
5. The system of claim 1 , wherein said first electrode has an inlet, and said second electrode has an aperture that provides communication between said first ionization chamber and said detector.
6. The system of claim 1 , wherein said first electrode has a higher voltage potential than said second electrode.
7. The system of claim 1 , wherein said first electrode has a lower voltage potential than said second electrode.
8. The system of claim 1 , wherein said first photo-ionizer is located in a second ionization chamber.
9. The system of claim 1 , further comprising a pump coupled to said first ionization chamber to create a vacuum in said first ionization chamber.
10. The system of claim 8 , wherein said second ionization chamber has a pressure of approximately one atmosphere.
11. The system of claim 1 , wherein said detector includes a mass spectrometer.
12. A method for detecting a trace molecule from a sample, comprising:
ionizing a sample with a glow discharge ionizer that has a first electrode, and a second electrode separated by a first ionization chamber;
ionizing the sample with a first photo-ionizer in the first ionization chamber; and,
detecting a trace molecule from the ionized sample.
13. The method of claim 12 , wherein the first photo-ionizer emits a beam of light that impinges on a photocathode to create electrons.
14. The method of claim 13 , further comprising accelerating the electrons toward a lamp electrode.
15. The method of claim 12 , ionizing the sample with a second photo-ionizer.
16. The method of claim 12 , wherein the sample is simultaneously ionized by the glow discharge ionizer and the first photo-ionizer.
17. The method of claim 12 , wherein the glow discharge ionizer creates negative ions and the first photo-ionizer creates positive ions.
18. A detector system that detects a trace molecule from a sample, comprising:
a glow discharge ionizer that includes a first electrode, and a second electrode separated by a first ionization chamber, said glow discharge ionizer ionizes the sample ionization chamber;
a first photo-ionizer that ionizes the sample;
a photocathode coupled to said first photo-ionizer; and,
a detector coupled to said ionization chamber.
19. The system of claim 18 , further comprising a lamp electrode coupled to said photocathode.
20. The system of claim 18 , further comprising a second photo-ionizer located within said ionization chamber.
21. The system of claim 18 , wherein said detector includes a mass spectrometer.
22. A method for detecting a trace molecule from a sample, comprising:
ionizing a sample by directing a light beam from a first photo-ionizer onto a photocathode to release an electron;
ionizing the sample with a second photo-ionizer; and,
detecting a trace molecule from the ionized sample.
23. The method of claim 22 , further comprising accelerating the electrons toward a lamp electrode.
24. The method of claim 23 , wherein the first photo-ionizer and the photocathode create negative ions, and the second photo-ionizer creates positive ions.