US3560734A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Quadrupole mass filter with fringing-field penetrating structure
Assignee: Individual
•
Filing: 1968-06-26
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Granted: 1971-02-02
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Expires: 1988-06-26
Abstract
Abstract An ion source positioned near the entrance of a quadrupole mass filter focuses a beam of positive ions at a point inside the quadrupole where the defocusing effect of the fringing field is substantially reduced. This beam of ions passes into the quadrupole through two concentric conical electrodes operated at different potentials and positioned with their larger ends outside the quadrupole near the ion source and their smaller ends inside the quadrupole near the focal point of the ion beam. An ion detector positioned near the exit of the quadrupole receives ions transmitted by the quadrupole. These ions pass through two concentric cylindrical electrodes operated at different potentials and positioned between the exit of the quadrupole and the ion detector.
Inventors
- 👤 Edward F Barnett
- 👤 William S W Tandler
- 👤 Wilson R Turner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:34
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/26; H01J49/34; H01J49/42; H01J49/4205; H01J49/421; H01J49/4215; H01J49/02; H01J49/06; H01J49/067
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
105 words
A multipole mass filter comprising: a plurality of substantially parallel primary electrodes spaced symmetrically about a central axis and provided with terminal means for receiving an excitation voltage including AC and DC components balanced with respect to a reference potential to produce alternating and static multipole electric field components in the central region between the primary electrodes; and a tubular electrode disposed about the central axis adjacent to one end of the primary electrodes, said tubular electrode being positioned with one end lying outside the central region between the primary electrodes and with the other end lying inside the central region between the primary electrodes.
Claim 2
Dependent Claim
105 words
A multipole mass filter comprising: a plurality of substantially parallel primary electrodes spaced symmetrically about a central axis and provided with terminal means for receiving an excitation voltage including AC and DC components balanced with respect to a reference potential to produce alternating and static multipole electric field components in the central region between the primary electrodes; and a tubular electrode disposed about the central axis adjacent to one end of the primary electrodes, said tubular electrode being positioned with one end lying outside the central region between the primary electrodes and with the other end lying inside the central region between the primary electrodes.
Claim 3
Dependent Claim
65 words
A multipole mass filter as in claim 1 including another tubular electrode at least partially enclosing the first-mentioned tubular electrode, said tubular electrodes being conically shaped and concentrically mounted about the central axis for operating at different potentials with their larger openings lying outside the central region between the primary electrodes and with their smaller openings lying inside the central region between the primary electrodes.
Claim 4
Dependent Claim
44 words
A multipole mass filter as in claim 2 including means positioned near the larger opening of the inner conical tubular electrode for focusing a beam of ions at a region along the central axis near the smaller opening of the inner conical tubular electrode.
Claim 5
Dependent Claim
44 words
A quadrupole mass filter as in claim 3 wherein said last-mentioned means comprises an ion source for focusing the ion beam at a point on the central axis inside the quadrupole where the defocusing effect of the multipole electric field components is substantially reduced.
Claim 6
Dependent Claim
42 words
A quadrupole mass filter as in claim 4 wherein the smaller openings of the inner and outer conical tubular electrodes lie in a plane normally intersecting the central axis substantially at the focal point of the ion beam from the ion source.
Claim 7
Dependent Claim
58 words
A quadrupole mass filter as in claim 5 wherein the inner conical tubular electrode is operated at a potential of greater magnitude than both the outer conical tubular electrode and the ion source and of a sign for accelerating ions to a higher axial velocity within the inner conical tubular electrode than they have further inside the quadrupole.
Claim 8
Dependent Claim
49 words
A quadrupole mass filter as in claim 1 wherein said tubular electrode is conically shaped and concentrically mounted about the central axis with its larger opening lying outside the central region between the primary electrodes and with its smaller opening lying inside the central region between the primary electrodes.
Claim 9
Dependent Claim
44 words
A multipole mass filTer as in claim 1 including an ion source positioned adjacent to said one end of the tubular electrode for focusing a beam of ions at a region along the central axis adjacent to said other end of the tubular electrode.
Claim 10
Dependent Claim
34 words
A multipole mass filter as in claim 1 including another tubular electrode disposed adjacent to said first-mentioned tubular electrode, said tubular electrodes being concentrically mounted about the central axis for operating at different potentials.
Claim 11
Dependent Claim
38 words
A multipole mass filter as in claim 9 wherein one of said tubular electrodes is operated at said reference potential and the other of said tubular electrodes is operated at a negative potential referred to said reference potential.
Claim 12
Dependent Claim
21 words
A multipole mass filter as in claim 10 wherein said last-mentioned tubular electrode at least partially encloses said first-mentioned tubular electrode.
Claim 13
Dependent Claim
64 words
A quadrupole mass filter as in claim 10 including: an ion source positioned adjacent to said one end of said first-mentioned tubular electrode for focusing a beam of ions at a region along the central axis adjacent to said other end of the first-mentioned tubular electrode; and an ion detector disposed along the central axis adjacent to the other end of the primary electrodes.
Claim 14
Dependent Claim
61 words
A quadrupole mass filter as in claim 12 wherein said tubular electrodes are concentrically disposed about the central axis adjacent to said one end of the primary electrodes, each of said tubular electrodes being positioned with one end lying outside the central region between the primary electrodes and with the other end lying inside the central region between the primary electrodes.
References Cited (Backward Citations)
US3371205A
Cited
US3457404A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-01 | 1974-08-03 | 1975-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-01 | 1978-08-03 | 1979-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-01 | 1982-08-03 | 1983-02-02 | $7700.00 | Window Closed / Lapsed |