US3668384A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mass spectrometer
Assignee: Bendix Corp
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Filing: 1969-04-01
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Granted: 1972-06-06
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Expires: 1989-04-01
Abstract
Abstract A mass spectrometer having means operatively connecting a circuit which provides a time lag between each ionizing electron pulse and each ion accelerating pulse to a delay circuit in an output scanner comprising the spectrometer so that each mass in the spectrum which is under observation will always be in best focus.
Inventors
- 👤 Charles J Moorman
- 👤 Richard H Lehman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:10
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/02; H01J49/025; H01J49/26; H01J49/34; H01J49/40; H01J49/403
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
323 words
In combination with a time-of-flight mass spectrometer of the type having an ionization chamber for receiving molecules of material to be analyzed, means for providing electron pulses to convert the molecules into ions, means for periodically accelerating the ions to provide ion pulses, said accelerating means including a grid disposed in said ionization chamber and means for applying a plurality of electrical pulses to said grid to accelerate ions out of said ionization chamber, a tube for receiving the ion pulses, means for measuring the time-of-flight through said tube of ions in said ion pulses, said measuring means including an electron multiplier having a plurality of channels for measuring electron current and means for gating electrons, said gating means including means for applying voltage pulses thereto to gate electrons associated with ions of a particular mass into a predetermined channel of said measuring means, the improvement comprising: said accelerating means further comprising an electrical circuit having means for establishing a first variable time delay between the end of each electron pulse and the beginning of each ion acceleration pulse applied to said grid to selectively vary the mass of the ion in best focus; means electrically connected to said gating means for establishing a second variable time delay between the beginning of each ion accelerating pulse applied to said grid and the beginning of each gate pulse to selectively vary the detection of electrons associated with different ion masses; means for applying said gate pulses to one of said electron multiplier channels in accordance with a predetermined time sequence to gate electrons associated with different masses into a predetermined channel for measurement; and means electrically connected to said first time delay circuit and said second time delay circuit to synchronously vary said first and second time delays so that as said gate pulses are sequentially applied to one of said electron multiplier channels each particular mass at the time is in best focus.
Claim 2
Dependent Claim
323 words
In combination with a time-of-flight mass spectrometer of the type having an ionization chamber for receiving molecules of material to be analyzed, means for providing electron pulses to convert the molecules into ions, means for periodically accelerating the ions to provide ion pulses, said accelerating means including a grid disposed in said ionization chamber and means for applying a plurality of electrical pulses to said grid to accelerate ions out of said ionization chamber, a tube for receiving the ion pulses, means for measuring the time-of-flight through said tube of ions in said ion pulses, said measuring means including an electron multiplier having a plurality of channels for measuring electron current and means for gating electrons, said gating means including means for applying voltage pulses thereto to gate electrons associated with ions of a particular mass into a predetermined channel of said measuring means, the improvement comprising: said accelerating means further comprising an electrical circuit having means for establishing a first variable time delay between the end of each electron pulse and the beginning of each ion acceleration pulse applied to said grid to selectively vary the mass of the ion in best focus; means electrically connected to said gating means for establishing a second variable time delay between the beginning of each ion accelerating pulse applied to said grid and the beginning of each gate pulse to selectively vary the detection of electrons associated with different ion masses; means for applying said gate pulses to one of said electron multiplier channels in accordance with a predetermined time sequence to gate electrons associated with different masses into a predetermined channel for measurement; and means electrically connected to said first time delay circuit and said second time delay circuit to synchronously vary said first and second time delays so that as said gate pulses are sequentially applied to one of said electron multiplier channels each particular mass at the time is in best focus.
References Cited (Backward Citations)
US2810075A
Cited
US3340395A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |