US3761708A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron suppressor grid for a mass spectrometer
Assignee: United States Department of the Interior
•
Filing: 1971-10-08
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Granted: 1973-09-25
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Expires: 1991-10-08
Abstract
Abstract A suppressor grid is positioned between an ionizer and 1n ion gauge in a mass spectrometer. The suppressor grid prevents electron interference with the ion gauge for operation at ultrahigh vacuum levels.
Inventors
- 👤 W Roepke
- 👤 K Pung
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:43
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/02; H01J49/10; H01J49/14
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
84 words
A mass spectrometer comprising in combination: an ionizer section having a total vapor pressure less than approximately 2.5(10) 9 torr for forming and accelerating positive ions in a vacuum environment; a nude ion gauge for monitoring the total vapor pressure in the same environment; and an electron suppressor grid including a negative or positive potential wire screen positioned on a line-of-sight path between said ionizer section and said ion gauge, and having sufficient potential to prevent electron interference between said ionizer and ion gauge.
Claim 2
Dependent Claim
84 words
A mass spectrometer comprising in combination: an ionizer section having a total vapor pressure less than approximately 2.5(10) 9 torr for forming and accelerating positive ions in a vacuum environment; a nude ion gauge for monitoring the total vapor pressure in the same environment; and an electron suppressor grid including a negative or positive potential wire screen positioned on a line-of-sight path between said ionizer section and said ion gauge, and having sufficient potential to prevent electron interference between said ionizer and ion gauge.
Claim 3
Dependent Claim
25 words
A mass spectrometer as claimed in claim 1 in which: the potential on the electron suppressor grid is on the order of minus 150 volts.
Claim 4
Dependent Claim
25 words
A mass spectrometer as claimed in claim 1 in which: the potential on the electron suppressor grid is on the order of plus 250 volts.
Claim 5
Independent Claim
90 words
A method for preventing electron cross-coupling between an ionizer section and a nude ion gauge in a mass spectrometer having an ultra high vacuum chamber with a pressure less than approximately 2.5(10) 9 torr compris-ing the steps of: ionizing the neutral atoms and molecules in said ionizer section to produce positive ions; measuring the total vapor pressure in said chamber by said nude ion gauge and preventing electron cross-coupling between said ionizer section and ion gauge by positioning a suppressor grid with an appropriate potential on a line-of-sight path therebetween.
Claim 6
Independent Claim
90 words
A method for preventing electron cross-coupling between an ionizer section and a nude ion gauge in a mass spectrometer having an ultra high vacuum chamber with a pressure less than approximately 2.5(10) 9 torr compris-ing the steps of: ionizing the neutral atoms and molecules in said ionizer section to produce positive ions; measuring the total vapor pressure in said chamber by said nude ion gauge and preventing electron cross-coupling between said ionizer section and ion gauge by positioning a suppressor grid with an appropriate potential on a line-of-sight path therebetween.
References Cited (Backward Citations)
US3057996A
Cited
US3265890A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |