US3582645A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combined field and impact ionization source for mass spectrometers
Assignee: Finnigan MAT GmbH
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Filing: 1967-11-07
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Granted: 1971-06-01
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Expires: 1987-11-07
Abstract
Abstract A combined field and impact ionization source includes a conducting housing embracing the trajectory of an electron beam for producing ions by impact. The conducting housing includes an ion exit gap through which an electric field leads ions produced by impact to a mass spectrometer. The conducting housing also functions as a counterelectrode that coacts with an emitter electrode of very small radius of curvature to comprise a field ionization source when the conducting housing is highly negative, such as 10 kilovolts, relative to the emitter electrode to produce ions by field ionization that are guided through the ion exit gap to the mass spectrometer.
Inventors
- 👤 Curt Brunnee
- 👤 Kurt Elfenbein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:25
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/02; H01J49/10; H01J49/14
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
181 words
A combined field and impact ionization source comprising, an electrically conducting housing having input and output apertures with an intermediate aperture therebetween, a source adjacent said input aperture of an electron beam having a trajectory through said input and output apertures, an emitter electrode adjacent to said intermediate aperTure for coaction with said conducting housing functioning as a counterelectrode comprising a field ionization source, means defining an exit gap for passing ions produced by impact and field ionization to a mass spectrometer, means applying predetermined potentials to said conducting housing including the portion thereof surrounding said intermediate aperture for selectively establishing an impact ionization electric field for both moving electrons along said trajectory to produce ions by impact and move the ions thus produced through said exit gap to a mass spectrometer, and means applying predetermined potential to said emitter electrode and said conducting housing including the portion thereof surrounding said intermediate aperture for selectively establishing a field ionization electric field for producing ions by field ionization and moving the ions thus produced through said exit gap to a mass spectrometer.
Claim 2
Dependent Claim
181 words
A combined field and impact ionization source comprising, an electrically conducting housing having input and output apertures with an intermediate aperture therebetween, a source adjacent said input aperture of an electron beam having a trajectory through said input and output apertures, an emitter electrode adjacent to said intermediate aperTure for coaction with said conducting housing functioning as a counterelectrode comprising a field ionization source, means defining an exit gap for passing ions produced by impact and field ionization to a mass spectrometer, means applying predetermined potentials to said conducting housing including the portion thereof surrounding said intermediate aperture for selectively establishing an impact ionization electric field for both moving electrons along said trajectory to produce ions by impact and move the ions thus produced through said exit gap to a mass spectrometer, and means applying predetermined potential to said emitter electrode and said conducting housing including the portion thereof surrounding said intermediate aperture for selectively establishing a field ionization electric field for producing ions by field ionization and moving the ions thus produced through said exit gap to a mass spectrometer.
Claim 3
Dependent Claim
43 words
A combined field and impact ionization source in accordance with claim 1 and further comprising means for relatively positioning said conducting housing, said electron beam source and said emitter electrode so that the regions of impact ionization and of field ionization substantially coincide.
Claim 4
Dependent Claim
56 words
A combined field and impact ionization source in accordance with claim 1 and further comprising means for relatively positioning said conducting housing, said electron beam source and said emitter electrode so that the region of impact ionization is along said trajectory, and said emitter electrode and the region of field ionization are outside said conducting housing.
Claim 5
Dependent Claim
27 words
A combined field and impact ionization source in accordance with claim 3 and further comprising a source of a vapor beam that embraces both said ionization regions.
Claim 6
Dependent Claim
36 words
A combined field and impact ionization source in accordance with claim 1 wherein said conducting housing is formed with a collar surrounding at least a portion of the region between said housing and said emitter electrode.
Claim 7
Dependent Claim
27 words
A combined field and impact ionization source in accordance with claim 1 and further comprising means for selectively withdrawing said emitter electrode away from said conducting housing.
Claim 8
Dependent Claim
52 words
A combined field and impact ionization source in accordance with claim 6 wherein said source includes an enclosure and said means for selectively withdrawing comprises a pivotable lever attached to said emitter electrode and secured to said enclosure about a pivot point, with means extending through said enclosure for operating said lever.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |