US3742275A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ion source having improved ion beam alignment and focus structure
Assignee: Varian Medical Systems Inc
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Filing: 1971-03-04
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Granted: 1973-06-26
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Expires: 1991-03-04
Abstract
Abstract An ion source comprising a plurality of components arranged along the ion beam path including a source body, repeller and extractor electrodes, a lens structure including an alignment electrode and a focus electrode, and an aperture plate. Certain of the components are made from common parts including the alignment and focus electrodes, each of which is formed by a metallic disk having a rectangular aperture centrally disposed therein but located slightly off axial center. The two electrodes are mounted along the beam path so that the two apertures are off-set in mutually opposite directions. Only a portion of the aperture of each electrode is aligned along the beam axis through which the beam passes for alignment and focussing.
Inventors
- 👤 R Gutow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:38
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/02; H01J49/10
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
297 words
An ion source comprising a source body adapted to enclose a gas sample, means including an electrical filament for producing an electron beam within said source body to produce positive ions from said gas sample, means for extracting a beam of ions from said source including an extractor electrode having an aperture, an alignment electrode and focus electrode mutually spaced-apart and spaced in fRont of said extracting means, each of said latter electrodes having a slot therein, the slot in said alignment electrode being off-center relative to said ion beam in one direction and the slot in said focus electrode being off-center relative to said ion beam in the opposite direction, a portion of each of said slots being aligned with said ion beam in mutually spatial overlap, and an aperture means including an aperture slit positioned in front of said alignment-focus electrode pair, said alignment-focus electrode pair operating to align the ion beam passing from said extractor electrode aperture and to focus said ion beam onto said aperture slit in said aperture means wherein said alignment electrode comprises a flat metallic member and wherein said alignment electrode slot is rectangular, and wherein said focus electrode comprises a second flat metallic member essentially identical to said alignment electrode facing in the opposite direction to said alignment electrode such that each said slot is off-set from the axis in the opposite direction and wherein said aperture means comprises a first thin metallic member having a narrow slit in the center thereof, and a support member on which said first thin metallic member having a narrow slit in the center thereof, and a support member on which said first thin metallic member is mounted, said support member comprising a third flat metallic member essentially identical to said alignment electrode.
Claim 2
Dependent Claim
297 words
An ion source comprising a source body adapted to enclose a gas sample, means including an electrical filament for producing an electron beam within said source body to produce positive ions from said gas sample, means for extracting a beam of ions from said source including an extractor electrode having an aperture, an alignment electrode and focus electrode mutually spaced-apart and spaced in fRont of said extracting means, each of said latter electrodes having a slot therein, the slot in said alignment electrode being off-center relative to said ion beam in one direction and the slot in said focus electrode being off-center relative to said ion beam in the opposite direction, a portion of each of said slots being aligned with said ion beam in mutually spatial overlap, and an aperture means including an aperture slit positioned in front of said alignment-focus electrode pair, said alignment-focus electrode pair operating to align the ion beam passing from said extractor electrode aperture and to focus said ion beam onto said aperture slit in said aperture means wherein said alignment electrode comprises a flat metallic member and wherein said alignment electrode slot is rectangular, and wherein said focus electrode comprises a second flat metallic member essentially identical to said alignment electrode facing in the opposite direction to said alignment electrode such that each said slot is off-set from the axis in the opposite direction and wherein said aperture means comprises a first thin metallic member having a narrow slit in the center thereof, and a support member on which said first thin metallic member having a narrow slit in the center thereof, and a support member on which said first thin metallic member is mounted, said support member comprising a third flat metallic member essentially identical to said alignment electrode.
Claim 3
Dependent Claim
64 words
An ion source as claimed in claim 1 wherein said aperture means further comprises a second thin metallic member having a narrow slit in the center thereof and spaced from said first thin metallic member along said beam path, and a further support member on which said second thin member is mounted comprising a fourth flat metallic member essentially identical to said alignment electrode.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |