US3681600A
Expired / Lapsed
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Retarding field electron spectrometer
Assignee: Applied Biosystems Inc
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Filing: 1969-10-24
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Granted: 1972-08-01
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Expires: 1989-10-24
Abstract
Abstract An electron spectrometer suitable for use in Electron Spectroscopy Chemical Analysis, or in Auger Electron Spectroscopy employs either an X-ray source or an electron beam source for exciting electrons from the surface of a test sample in vacuum. A substantial free drift path through a wide spherical angle is provided for ejected electrons, together with a pair of spaced apart spherically shaped retarding potential grids having a plurality of fringing field correction rings therebetween and the situs of a test sample as the center of their curvature, a cylindrical pot-shaped general electron integral current collector anode lined with a negatively biased screen grid secondary electron repeller, and a small conically shaped selective electron, differential current collector insulatingly passed through a central coaxial opening in the anode and connected to an electron multiplier output. The entire structure is enclosed in a vacuum within an external ferromagnetic casing which provides both electrostatic and electromagnetic shielding. Additionally an external magnetic shield is employed, or Helmholtz coils may be used, to reduce stray magnetic fields to not more than 10 milligauss. The device accommodates relatively large test samples, employs no input or output slits and hence provides a substantially greater signal level than prior spectrometers, and is capable of high resolution of the order of 0.04 percent.
Inventors
- 👤 Jameson Dane Rigden
- 👤 David A Huchital
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:47
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/44; H01J49/46; H01J49/48; H01J49/488
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
143 words
In a retarding potential difference electron spectrometer having a plurality of retarding grids, a post monochromator comprising in combination, A. an integral current collector anode cup positioned beyond the last retarding grid and substantially concentric with an axis normal to the center of said grid, B. a secondary electron suppressor grid within said anode cup in proximity to but insulated from the inner surfaces thereof, 1. means applying a negative potential to said suppressor grid, 2. aligned axial apertures formed in the center of said suppressor grid and in the center of said anode cup, C. a differential current collector insulatingly passing through said aligned apertures, and 1. means applying a positive potential with respect to said secondary electron suppressor to said differential current collector, whereby slower electrons are focused by the secondary electron suppressor and are captured by said differential current collector.
Claim 2
Dependent Claim
143 words
In a retarding potential difference electron spectrometer having a plurality of retarding grids, a post monochromator comprising in combination, A. an integral current collector anode cup positioned beyond the last retarding grid and substantially concentric with an axis normal to the center of said grid, B. a secondary electron suppressor grid within said anode cup in proximity to but insulated from the inner surfaces thereof, 1. means applying a negative potential to said suppressor grid, 2. aligned axial apertures formed in the center of said suppressor grid and in the center of said anode cup, C. a differential current collector insulatingly passing through said aligned apertures, and 1. means applying a positive potential with respect to said secondary electron suppressor to said differential current collector, whereby slower electrons are focused by the secondary electron suppressor and are captured by said differential current collector.
Claim 3
Dependent Claim
31 words
aligned axial apertures formed in the center of said suppressor grid and in the center of said anode cup, C. a differential current collector insulatingly passing through said aligned apertures, and
Claim 4
Dependent Claim
31 words
aligned axial apertures formed in the center of said suppressor grid and in the center of said anode cup, C. a differential current collector insulatingly passing through said aligned apertures, and
Claim 5
Dependent Claim
14 words
The combination of claim 1 wherein said differential current collector includes an electron multiplier.
Claim 6
Dependent Claim
54 words
a major open end of said conical shield spaced from said truncated apex end, D. first and second retarding spherical grids positioned beyond the major open end of said conical shield and having a common center of curvature substantially coinciding with the intersection of said beam axis with the axis of said conical shield,
Claim 7
Dependent Claim
54 words
a major open end of said conical shield spaced from said truncated apex end, D. first and second retarding spherical grids positioned beyond the major open end of said conical shield and having a common center of curvature substantially coinciding with the intersection of said beam axis with the axis of said conical shield,
Claim 8
Dependent Claim
38 words
said second grid further spaced from said sample holder by a radius R1 + X, E. a cylindrical cup shaped collector anode coaxial with said conical shield and positioned beyond said second grid by an axial distance Y,
Claim 9
Dependent Claim
38 words
said second grid further spaced from said sample holder by a radius R1 + X, E. a cylindrical cup shaped collector anode coaxial with said conical shield and positioned beyond said second grid by an axial distance Y,
Claim 10
Dependent Claim
34 words
an axial opening through the center of said anode and said repeller screen, and F. a substantially conically shaped differential current collector insulatingly inserted through said axial opening and connected with an electron multiplier.
Claim 11
Dependent Claim
34 words
an axial opening through the center of said anode and said repeller screen, and F. a substantially conically shaped differential current collector insulatingly inserted through said axial opening and connected with an electron multiplier.
Claim 12
Dependent Claim
9 words
said first grid having a radius of curvature R1,
Claim 13
Dependent Claim
9 words
said first grid having a radius of curvature R1,
Claim 14
Dependent Claim
55 words
a major open end of said conical shield spaced from said truncated apex end, D. first and second retarding spherical grids positioned beyond the major open end of said conical shield and having a common center of curvature substantially coinciding with the intersection of said energy beam axis with the axis of said conical shield,
Claim 15
Dependent Claim
55 words
a major open end of said conical shield spaced from said truncated apex end, D. first and second retarding spherical grids positioned beyond the major open end of said conical shield and having a common center of curvature substantially coinciding with the intersection of said energy beam axis with the axis of said conical shield,
Claim 16
Dependent Claim
38 words
said second grid further spaced from said sample holder by a radius R1 + X, E. a cylindrical cup shaped collector anode coaxial with said conical shield and positioned beyond said second grid by an axial distance Y,
Claim 17
Dependent Claim
38 words
said second grid further spaced from said sample holder by a radius R1 + X, E. a cylindrical cup shaped collector anode coaxial with said conical shield and positioned beyond said second grid by an axial distance Y,
Claim 18
Dependent Claim
34 words
an axial opening through the center of said anode and said repeller screen, and F. a substantially conically shaped differential current collector insulatingly inserted through said axial opening and connected with an electron multiplier.
Claim 19
Dependent Claim
34 words
an axial opening through the center of said anode and said repeller screen, and F. a substantially conically shaped differential current collector insulatingly inserted through said axial opening and connected with an electron multiplier.
Claim 20
Dependent Claim
31 words
aligned axial apertures formed in the center of said lateral grid and in the center of said anode cup, D. a differential current collector insulatingly passing through said aligned apertures, and
Claim 21
Dependent Claim
31 words
aligned axial apertures formed in the center of said lateral grid and in the center of said anode cup, D. a differential current collector insulatingly passing through said aligned apertures, and
Claim 22
Dependent Claim
43 words
said second grid having a radius of curvature R2, C. the relationship between grid radii, grid mesh and sample diameter where: R approximately equals (ds2/2 Square Root 2 R12) and R approximately equals (1/ Square Root 2) . (R2 - R1/ delta ).
Claim 23
Dependent Claim
43 words
said second grid having a radius of curvature R2, C. the relationship between grid radii, grid mesh and sample diameter where: R approximately equals (ds2/2 Square Root 2 R12) and R approximately equals (1/ Square Root 2) . (R2 - R1/ delta ).
Claim 24
Dependent Claim
63 words
In a retarding potential difference electron spectrometer having a plurality of retarding grids, a post monochromator comprising in combination, A. an integral current collector anode cup positioned beyond the last retarding grid and substantially concentric with an axis normal to the center of said grid, B. a coaxial secondary electron suppressor grid within said anode cup in proximity to the inner sidewall thereof,
Claim 25
Dependent Claim
63 words
In a retarding potential difference electron spectrometer having a plurality of retarding grids, a post monochromator comprising in combination, A. an integral current collector anode cup positioned beyond the last retarding grid and substantially concentric with an axis normal to the center of said grid, B. a coaxial secondary electron suppressor grid within said anode cup in proximity to the inner sidewall thereof,
Claim 26
Dependent Claim
22 words
The combination of claim 3 wherein said differential current collector is connected to an electron multiplier to produce an amplified differential output.
Claim 27
Dependent Claim
80 words
In a retarding field electron spectrometer the combination comprising, A. beam source of energy directed to impinge upon a sample of material in a vacuum, B. a sample holder intersecting the path of said energy beam and positioned at an angle to the axis of said beam, C. a conical electrostatic shield having its axis of revolution substantially normal to the axis of said beam and in alignment with the point of intersection of said beam with said sample holder,
Claim 28
Dependent Claim
80 words
In a retarding field electron spectrometer the combination comprising, A. beam source of energy directed to impinge upon a sample of material in a vacuum, B. a sample holder intersecting the path of said energy beam and positioned at an angle to the axis of said beam, C. a conical electrostatic shield having its axis of revolution substantially normal to the axis of said beam and in alignment with the point of intersection of said beam with said sample holder,
Claim 29
Dependent Claim
15 words
The combination of claim 5 wherein said energy source produces a substantially monochromatic X-ray beam.
Claim 30
Dependent Claim
14 words
The combination of claim 5 wherein said energy source comprises an electron beam gun.
Claim 31
Dependent Claim
40 words
In a retarding potential spherical grid electron spectrometer having a resolving power R, A. a sample holder having a diameter ds, B. first and second retarding grids each formed of spherical screen segments, having a mesh of (1/ delta ),
Claim 32
Dependent Claim
40 words
In a retarding potential spherical grid electron spectrometer having a resolving power R, A. a sample holder having a diameter ds, B. first and second retarding grids each formed of spherical screen segments, having a mesh of (1/ delta ),
Claim 33
Dependent Claim
21 words
The combination of claim 5 wherein: R1 approximately equals 35 cm X approximately equals 6 cm Y approximately equals 10 cm.
Claim 34
Dependent Claim
48 words
The combination of claim 5 including a pre-deceleration grid interposed between said sample holder and said first retarding spherical grid, said pre-deceleration grid being mounted in the truncated apex end of said conical electrostatic shield, and the sample holder is biased positively with respect to said pre-deceleration grid.
Claim 35
Dependent Claim
30 words
The combination of claim 5 including an electron opaque shadow mask centrally located on the axis of said conical shield between said sample holder and said first retarding spherical grid.
Claim 36
Dependent Claim
32 words
The combination of claim 5 wherein the mesh of said first and second retarding spherical grids is more closely woven and of a larger diameter wire than said secondary electron repeller screen.
Claim 37
Dependent Claim
47 words
The combination of claim 12 wherein the mesh of said first and second retarding spherical grids is approximately twice the mesh of said secondary electron repeller screen, and the diameter of said first and second grid wires is approximately twice the diameter of said repeller screen wire.
Claim 38
Dependent Claim
54 words
The combination of claim 13 wherein said first and second retarding spherical grids are formed of stainless steel wire approximately 0.002 inch in diameter and of approximately 100 X 100 mesh, and said secondary repeller screen is formed of stainless steel wire approximately 0.001 inch in diameter and of approximately 50 X 50 mesh.
Claim 39
Dependent Claim
40 words
The combination of claim 5 wherein said sample holder is formed as a substantially right circular cone of stainless steel coaxial with said conical electrostatic shield and having its apex directed toward the center of said first retarding spherical grid.
Claim 40
Dependent Claim
66 words
The combination of claim 5 including a plurality of circular fringing field correction rings having inner diameters substantially equal to the diameters of said first and second retarding spherical grids and substantially greater outer diameters, said correction rings insulatingly mounted in stacked and substantially uniform spaced relation between said first and second spherical grids and coaxial with said conical electrostatic shield and said cylindrical anode cup.
Claim 41
Dependent Claim
39 words
The combination of claim 16 wherein the one of said correction rings adjacent to said first retarding spherical grid is electrically connected thereto and the one of said rings adjacent to said second spherical grid is electrically connected thereto.
Claim 42
Dependent Claim
33 words
The combination of claim 17 including fixed resistance elements connected between adjacent fringing field correction rings whereby successive rings between said first and second retarding spherical grids are charged with increasing negative potentials.
Claim 43
Dependent Claim
79 words
In a retarding field electron spectrometer the combination comprising, A. a substantially monochromatic energy source producing a beam of radiant energy, B. a sample holder intersecting the beam path of said energy source and positioned at an angle to the axis of said beam, C. a conical electrostatic shield having its axis of revolution substantially normal to the axis of said energy source beam and in alignment with the point of intersection of said beam with said sample holder,
Claim 44
Dependent Claim
79 words
In a retarding field electron spectrometer the combination comprising, A. a substantially monochromatic energy source producing a beam of radiant energy, B. a sample holder intersecting the beam path of said energy source and positioned at an angle to the axis of said beam, C. a conical electrostatic shield having its axis of revolution substantially normal to the axis of said energy source beam and in alignment with the point of intersection of said beam with said sample holder,
Claim 45
Dependent Claim
14 words
The combination of claim 19 wherein said energy source comprises an electron beam gun.
Claim 46
Dependent Claim
21 words
The combination of claim 19 wherein: R1 approximately equals 35 cm X approximately equals 6 cm Y approximately equals 10 cm.
Claim 47
Dependent Claim
13 words
The combination of claim 19 wherein said energy source comprises an X-ray generator.
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) | 1975-08-01 | 1976-01-31 | 1976-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-01 | 1980-01-31 | 1980-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-01 | 1984-01-31 | 1984-08-01 | $7700.00 | Window Closed / Lapsed |