Patent US3619684A successfully refreshed from Google Patents.
US3619684A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ion source
Assignee: US Philips Corp
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Filing: 1970-04-23
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Granted: 1971-11-09
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Expires: 1990-04-23
Abstract
Abstract A nonmagnetic, electron impact ion source comprising an evacuated envelope having means for passing ionizing gases through the envelope. Within the envelope, an electron emitting cathode is positioned adjacent a grid-shaped ionization chamber. A conducting wall section of the ionization chamber that is impenetrable to ions has an ion exiting aperture, which is adjacent to a grid-shaped electrode for extracting ions. The extracting electrode is positioned at a distance of a few tenths of a mm. from the ion exiting aperture, and kept at a small negative voltage not exceeding 5 volts relative to the ionization chamber. An acceleration electrode adjacent to the extracting electrode forms ions from the ionization chamber into beams. A screen grid placed between the extracting and acceleration electrodes prevents the high negative voltage of the acceleration electrode from affecting the electric field within the ionization chamber.
Inventors
- 👤 Derek Andrew
- 👤 Lawrence Graham Pittaway
- 👤 Thomas Chrisholm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:51
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/02; H01J49/10; H01J49/14
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
150 words
A nonmagnetic ion source comprising an evacuated envelope having means for receiving ionizing gases, an electron emitting cathOde operating at a negative voltage within said envelope, an ionization chamber adjacent to said cathode and operating at a positive voltage relative to said cathode for containing ions produced by collisions of electrons from said cathode with said ionizing gases, said ionization chamber formed from grid-shaped, electrically conductive walls and an electrically conductive wall section impenetrable to ions, said wall section having an ion exiting aperture, a grid-shaped ion extracting electrode operating at a negative voltage not greater than 5 volts relative to said ionization chamber, said extracting electrode positioned within a distance of a few tenths of a mm. adjacent to said ion exiting aperture, and an accelerating electrode adjacent to said ion extracting electrode and operating at a negative voltage relative to said chamber to form said ions into beams.
Claim 2
Dependent Claim
150 words
A nonmagnetic ion source comprising an evacuated envelope having means for receiving ionizing gases, an electron emitting cathOde operating at a negative voltage within said envelope, an ionization chamber adjacent to said cathode and operating at a positive voltage relative to said cathode for containing ions produced by collisions of electrons from said cathode with said ionizing gases, said ionization chamber formed from grid-shaped, electrically conductive walls and an electrically conductive wall section impenetrable to ions, said wall section having an ion exiting aperture, a grid-shaped ion extracting electrode operating at a negative voltage not greater than 5 volts relative to said ionization chamber, said extracting electrode positioned within a distance of a few tenths of a mm. adjacent to said ion exiting aperture, and an accelerating electrode adjacent to said ion extracting electrode and operating at a negative voltage relative to said chamber to form said ions into beams.
Claim 3
Dependent Claim
40 words
A nonmagnetic ion source as claimed in claim 1 further comprising a grid-shaped electrode between said cathode and said envelope and operating at a negative voltage relative to said cathode for directing electrons from said filament to said ionization chamber.
Claim 4
Dependent Claim
38 words
A nonmagnetic ion source as claimed in claim 1 further comprising a reflector electrode operating at a positive voltage relative to said ionization chamber and surrounding said ionization chamber to prevent ions from escaping through said grid-shaped walls.
Claim 5
Dependent Claim
51 words
A nonmagnetic ion source as claimed in claim 1 further comprising a screen grid operating at a negative voltage relative to said ionization chamber and positioned between said extracting and accelerating electrodes to prevent the electric field of said accelerating electrode from penetrating into said ionization chamber through said extracting electrode.
References Cited (Backward Citations)
US3281617A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-08 | 1975-05-10 | 1975-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-08 | 1979-05-10 | 1979-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-08 | 1983-05-10 | 1983-11-09 | $7700.00 | Window Closed / Lapsed |