Patent US3579270A successfully refreshed from Google Patents.
US3579270A
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Energy selective ion beam intensity measuring apparatus and method utilizing a scintillator to detect electrons generated by the beam
Assignee: United Kingdom Atomic Energy Authority
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Filing: 1968-10-22
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Granted: 1971-05-18
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Expires: 1988-10-22
Abstract
Abstract The apparatus is primarily intended for use with ion beams from mass spectrometers, and has one application in determining metastable ion spectra. It comprises a retarding electrode carrying a scintillator detector and preceded by an apertured electrode. When the retarding electrode voltage equals or exceeds the source accelerating voltage, all ions are repelled to the apertured electrode where secondary electrons are produced which are accelerated to the scintillator and an output is obtained from a photomultiplier located beyond the retarding electrode. When the retarding electrode voltage is less than the source accelerating voltage only ions resulting from metastable fragmentations (which have less energy) are so repelled. The parent ions strike the scintillator but produce no output because the latter is coated with an ion-opaque layer. A second, apertured, retarding electrode can precede the above-described arrangement, to which a lower voltage is applied, thus setting a lower as well as an upper limit to the ion energy detected and making the apparatus of more general application as an energy range selector.
Inventors
- 👤 Norman Richard Daly
- 👤 Royal Edward Powell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:29
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/44; H01J49/46; H01J49/48; H01J49/488; G; G01; G01T; G01T1/00; G01T1/16; G01T1/28; G01T1/29; H01J49/02; H01J49/025
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
89 words
Ion beam intensity measuring apparatus suitable for use with a mass spectrometer comprising a first apertured electrode for admitting the ion beam and having a surface capable of emitting secondary electrons, a first retarding electrode located beyond said first apertured electrode to apply a retarding electric field to ions passing through the aperture, a detectOr for detecting secondary electrons emitted from said first apertured electrode by ions repelled to said first apertured electrode by said field, and a connection for applying a variable potential to said first retarding electrode.
Claim 2
Dependent Claim
89 words
Ion beam intensity measuring apparatus suitable for use with a mass spectrometer comprising a first apertured electrode for admitting the ion beam and having a surface capable of emitting secondary electrons, a first retarding electrode located beyond said first apertured electrode to apply a retarding electric field to ions passing through the aperture, a detectOr for detecting secondary electrons emitted from said first apertured electrode by ions repelled to said first apertured electrode by said field, and a connection for applying a variable potential to said first retarding electrode.
Claim 3
Dependent Claim
23 words
Apparatus as claimed in claim 1 wherein said secondary electron detector is mounted on said first retarding electrode facing said first apertured electrode.
Claim 4
Dependent Claim
36 words
Apparatus as claimed in claim 2 wherein the surface of said secondary electron detector facing said first apertured electrode includes a coating which is substantially opaque to said ions but substantially transparent to said secondary electrons.
Claim 5
Dependent Claim
13 words
Apparatus as claimed in claim 3 wherein said coating is a metallic layer.
Claim 6
Dependent Claim
23 words
Apparatus as claimed in claim 3 wherein said detector is a translucent scintillator and forms the central portion of said first retarding electrode.
Claim 7
Dependent Claim
34 words
Apparatus as claimed in claim 5 wherein the photocathode of a photomultiplier tube is located beyond said first retarding electrode opposite that surface of said scintillator which faces away from said first apertured electrode.
Claim 8
Dependent Claim
41 words
Apparatus as claimed in claim 2 wherein said first apertured electrode is preceded by a second retarding electrode having an aperture and having a connection for applying thereto a variable potential less than the potential applied to said first retarding electrode.
Claim 9
Dependent Claim
14 words
Apparatus as claimed in claim 7 wherein said second retarding electrode includes a grid.
Claim 10
Dependent Claim
46 words
Apparatus as claimed in claim 2 wherein said first apertured electrode is preceded by a second apertured electrode arranged to be held at the same potential as said first apertured electrode and wherein an apertured electron-suppression electrode is located between said first and second apertured electrodes.
Claim 11
Dependent Claim
83 words
Apparatus as claimed in claim 7 wherein said first apertured electrode is preceded by a second apertured electrode arranged to be held at the same potential as said first apertured electrode, wherein an apertured electron-suppression electrode is located between said first and second apertured electrodes, wherein said second retarding electrode precedes said second apertured electrode, and wherein a third apertured electrode precedes said second retarding electrode and is arranged to be held at the same potential as said first and second apertured electrodes.
Claim 12
Dependent Claim
22 words
Apparatus as claimed in claim 2 wherein said first retarding electrode and said first apertured electrode are substantially parallel to one another.
Claim 13
Independent Claim
112 words
A method of measuring a metastable fragment ion spectrum with a mass spectrometer comprising admitting the ion beam through an apertured electrode having a surface capable of emitting secondary electrons, applying a potential to a retarding electrode located beyond the apertured electrode to repel ions back to said apertured electrode and thereby produce secondary electrons thereat, allowing said secondary electrons to impinge on a detector mounted on said retarding electrode, and varying the potential applied to said retarding electrode between a potential at which substantially all ions in the beam are repelled to said apertured electrode and a potential at which substantially only metastable fragment ions in the beam are so repelled.
Claim 14
Independent Claim
112 words
A method of measuring a metastable fragment ion spectrum with a mass spectrometer comprising admitting the ion beam through an apertured electrode having a surface capable of emitting secondary electrons, applying a potential to a retarding electrode located beyond the apertured electrode to repel ions back to said apertured electrode and thereby produce secondary electrons thereat, allowing said secondary electrons to impinge on a detector mounted on said retarding electrode, and varying the potential applied to said retarding electrode between a potential at which substantially all ions in the beam are repelled to said apertured electrode and a potential at which substantially only metastable fragment ions in the beam are so repelled.
Claim 15
Independent Claim
148 words
A method of measuring the intensity of ions in a beam within a desired energy range comprising causing the ion beam to approach an apertured retarding electrode, applying a potential to said apertured retarding electrode to repel ions below a selected energy approaching said apertured retarding electrode, admitting those ions which traverse said apertured retarding electrode through a further apertured electrode having a surface capable of emitting secondary electrons, applying a potential to a further retarding electrode located beyond said apertured electrode to repel ions below a further selected energy back to said apertured electrode and thereby produce secondary electrons thereat, allowing said secondary electrons to impinge oN a detector mounted on said further retarding electrode, the potential applied to said further retarding electrode being greater than that applied to the apertured retarding electrode and said potentials being selected to define between them the desired ion energy range.
Claim 16
Independent Claim
148 words
A method of measuring the intensity of ions in a beam within a desired energy range comprising causing the ion beam to approach an apertured retarding electrode, applying a potential to said apertured retarding electrode to repel ions below a selected energy approaching said apertured retarding electrode, admitting those ions which traverse said apertured retarding electrode through a further apertured electrode having a surface capable of emitting secondary electrons, applying a potential to a further retarding electrode located beyond said apertured electrode to repel ions below a further selected energy back to said apertured electrode and thereby produce secondary electrons thereat, allowing said secondary electrons to impinge oN a detector mounted on said further retarding electrode, the potential applied to said further retarding electrode being greater than that applied to the apertured retarding electrode and said potentials being selected to define between them the desired ion energy range.
References Cited (Backward Citations)
US3041453A
Cited
GB1078823A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-17 | 1974-11-16 | 1975-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-17 | 1978-11-16 | 1979-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-17 | 1982-11-16 | 1983-05-18 | $7700.00 | Window Closed / Lapsed |