US3955084A
Expired / Lapsed
US
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Electro-optical detector for use in a wide mass range mass spectrometer
Assignee: California Institute of Technology
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Filing: 1974-09-09
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Granted: 1976-05-04
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Expires: 1994-09-09
Abstract
Abstract An electro-optical detector is disclosed for use in a wide mass range mass spectrometer (MS), in the latter the focal plane is at or very near the exit end of the magnetic analyzer, so that a strong magnetic field of the order of 1000G or more is present at the focal plane location. The novel detector includes a microchannel electron multiplier array (MCA) which is positioned at the focal plane to convert ion beams which are focused by the MS at the focal plane into corresponding electron beams which are then accelerated to form visual images on a conductive phosphored surface. These visual images are then converted into images on the target of a vidicon camera or the like for electronic processing. Due to the strong magnetic field at the focal plane, in one embodiment of the invention, the MCA with front and back parallel ends is placed so that its front end forms an angle of not less than several degrees, preferably on the order of 10°-20°, with respect to the focal plane, with the center line of the front end preferably located in the focal plane. In another embodiment the MCA is wedge-shaped, with its back end at an angle of about 10°-20° with respect to the front end. In this embodiment the MCA is placed so that its front end is located at the focal plane.
Inventors
- 👤 Charles E. Giffin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:14
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/02; H01J49/025; H01J49/26; H01J49/28; H01J49/32; H01J49/322
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
197 words
An electro-optical detector for use with a mass spectrometer of the type focusing ion beams at a focal plane at substantially the exit end of a magnetic analyzer at which a magnetic field is present, the detector comprising: a microchannel electron multiplier array, defining a plurality of parallel hollow channels each with an inlet end and an outlet end, all of said inlet ends being in a first plane defining a front end of said array and the outlet ends being in a second plane defining a back end of said array, said array being located at said focal plane so that the front end faces said magnetic analyzer and at least said back end is at an angle with respect to said focal plane, whereby ions in said ion beams enter channels in said array through the inlet ends thereof, producing secondary electrons therein, said secondary electrons exiting said channels through said back end forming electron beams; and circuit means including electron-sensitive means spaced apart from the array back end and parallel thereto for intercepting each of said electron beams to form an image thereon and means for processing the images formed on said electron-sensitive means.
Claim 2
Dependent Claim
197 words
An electro-optical detector for use with a mass spectrometer of the type focusing ion beams at a focal plane at substantially the exit end of a magnetic analyzer at which a magnetic field is present, the detector comprising: a microchannel electron multiplier array, defining a plurality of parallel hollow channels each with an inlet end and an outlet end, all of said inlet ends being in a first plane defining a front end of said array and the outlet ends being in a second plane defining a back end of said array, said array being located at said focal plane so that the front end faces said magnetic analyzer and at least said back end is at an angle with respect to said focal plane, whereby ions in said ion beams enter channels in said array through the inlet ends thereof, producing secondary electrons therein, said secondary electrons exiting said channels through said back end forming electron beams; and circuit means including electron-sensitive means spaced apart from the array back end and parallel thereto for intercepting each of said electron beams to form an image thereon and means for processing the images formed on said electron-sensitive means.
Claim 3
Dependent Claim
20 words
An electro-optical detector as described in claim 1 wherein said angle is on the order of not less than 10°.
Claim 4
Dependent Claim
75 words
An electro-optical detector as described in claim 2 wherein said ion beams are of a selected height, and the beams are focused at said focal plane at different locations along a first axis, and said array being of a height not less than the height of the ion beams, with its length parallel to said first axis, with at least the center of said front end along the array length being in said focal plane.
Claim 5
Dependent Claim
92 words
An electro-optical detector as described in claim 1 wherein said front and back ends of said array are parallel to one another, with said front end defined by the height and length of said array, forming said angle with said focal plane with the center of said front end along the array length being located in said focal plane, whereby the inlet ends of channels along said center lie in said focal plane with the inlet ends of channels above and below said center being either ahead or beyond said focal plane.
Claim 6
Dependent Claim
20 words
An electro-optical detector as described in claim 4 wherein said angle is on the order of not less than 10°.
Claim 7
Dependent Claim
47 words
An electro-optical detector as described in claim 4 wherein said electron-sensitive means define a phosphorous surface substantially parallel to said back end and spaced apart therefrom, and said circuit means include means for accelerating said electrons exiting said array through said back end to said phosphorous surface.
Claim 8
Dependent Claim
40 words
An electro-optical detector as described in claim 1 wherein said back end forms said angle with respect to said front end and said array is wedge-shaped, with the front end of said array being located substantially at said focal plane.
Claim 9
Dependent Claim
58 words
An electro-optical detector as described in claim 7 wherein said electron-sensitive means define a phosphorous surface substantially parallel to said back end and spaced apart therefrom a distance on the order of not less than one millimeter, and said circuit means include means for accelerating said electrons exiting said array through said back end to said phosphorous surface.
Claim 10
Dependent Claim
20 words
An electro-optical detector as described in claim 7 wherein said angle is on the order of not less than 10°.
Claim 11
Dependent Claim
27 words
An electro-optical detector as described in claim 1 wherein said magnetic field at said focal plane is on the order of not less than 1000 gauss (G).
Claim 12
Dependent Claim
73 words
An electro-optical detector as described in claim 10 wherein said ion beams are focused at said focal plane at different locations along a first axis with the magnetic field at said focal plane being in a second axis perpendicular to said first axis, with the array length being disposed parallel to said first axis, with at least the center line in said front end along the array length being in said focal plane.
Claim 13
Dependent Claim
92 words
An electro-optical detector as described in claim 11 wherein said front and back ends of said array are parallel to one another, with said front end defined by the height and length of said array, forming said angle with said focal plane with the center of said front end along the array length being located in said focal plane, whereby the inlet ends of channels along said center lie in said focal plane with the inlet ends of channels above and below said center being either ahead or beyond said focal plane.
Claim 14
Dependent Claim
20 words
An electro-optical detector as described in claim 12 wherein said angle is on the order of not less than 10°.
Claim 15
Dependent Claim
40 words
An electro-optical detector as described in claim 11 wherein said back end forms said angle with respect to said front end and said array is wedge-shaped, with the front end of said array being located substantially at said focal plane.
Claim 16
Dependent Claim
20 words
An electro-optical detector as described in claim 14 wherein said angle is on the order of not less than 10°.
Claim 17
Dependent Claim
47 words
An electro-optical detector as described in claim 15 wherein said electron-sensitive means define a phosphorous surface substantially parallel to said back end and spaced apart therefrom, and said circuit means include means for accelerating said electrons exiting said array through said back end to said phosphorous surface.
Claim 18
Dependent Claim
26 words
An electro-optical detector as described in claim 1 wherein said means for processing comprise means for converting the images on said electron-sensitive means into electrical signals.
Claim 19
Dependent Claim
53 words
An electro-optical detector as described in claim 17 wherein said means for processing comprise vidicon means having a target exposable to images and means for converting the images on said target into related electrical signals, and means for transferring the images formed on said electron-sensitive means to the target of said vidicon means.
Claim 20
Dependent Claim
73 words
An electro-optical detector as described in claim 18 wherein said ion beams are focused at said focal plane at different locations along a first axis with the magnetic field at said focal plane being in a second axis perpendicular to said first axis, with the array length being disposed parallel to said first axis, with at least the center line in said front end along the array length being in said focal plane.
Claim 21
Dependent Claim
92 words
An electro-optical detector as described in claim 19 wherein said front and back ends of said array are parallel to one another, with said front end defined by the height and length of said array, forming said angle with said focal plane with the center of said front end along the array length being located in said focal plane, whereby the inlet ends of channels along said center lie in said focal plane with the inlet ends of channels above and below said center being either ahead or beyond said focal plane.
Claim 22
Dependent Claim
39 words
An electro-optical detector as described in claim 20 wherein said angle is on the order of not less than 10° and the magnetic field at said focal plane is on the order of not less than 1000 gauss (G).
Claim 23
Dependent Claim
40 words
An electro-optical detector as described in claim 19 wherein said back end forms said angle with respect to said front end and said array is wedge-shaped, with the front end of said array being located substantially at said focal plane.
Claim 24
Dependent Claim
39 words
An electro-optical detector as described in claim 22 wherein said angle is on the order of not less than 10° and the magnetic field at said focal plane is on the order of not less than 1000 gauss (G).
Claim 25
Dependent Claim
239 words
An electro-optical detector for use in a device in which separate beams of charged particles are focusable at different locations along a longitudinal axis in a focal plane which is in a magnetic field which is substantially in a direction perpendicular to said longitudinal axis, the detector comprising: a microchannel electron multiplier array, defining a plurality of parallel hollow channels each with an inlet end and an outlet end, all of said inlet ends being in a first plane defining a front end of said array and all the outlet ends being in a second plane defining a back end of said array, said array being positioned with its front end toward said separate beams with the array length parallel to said longitudinal axis, whereby the particles of different beams enter different groups of channels to generate secondary electrons, which exit the channels through said back end and forming separate electron beams, the array being positioned whereby at least its back end is at an angle with respect to said focal plane with at least the inlet ends of channels along a center line of said front end extending along the array length, being in said focal plane; and circuit means including electron-sensitive means which are parallel to said back end and spaced apart therefrom for intercepting said electron beams which form images thereon and means for processing said images, each image corresponding to a different charged particles' beam.
Claim 26
Dependent Claim
239 words
An electro-optical detector for use in a device in which separate beams of charged particles are focusable at different locations along a longitudinal axis in a focal plane which is in a magnetic field which is substantially in a direction perpendicular to said longitudinal axis, the detector comprising: a microchannel electron multiplier array, defining a plurality of parallel hollow channels each with an inlet end and an outlet end, all of said inlet ends being in a first plane defining a front end of said array and all the outlet ends being in a second plane defining a back end of said array, said array being positioned with its front end toward said separate beams with the array length parallel to said longitudinal axis, whereby the particles of different beams enter different groups of channels to generate secondary electrons, which exit the channels through said back end and forming separate electron beams, the array being positioned whereby at least its back end is at an angle with respect to said focal plane with at least the inlet ends of channels along a center line of said front end extending along the array length, being in said focal plane; and circuit means including electron-sensitive means which are parallel to said back end and spaced apart therefrom for intercepting said electron beams which form images thereon and means for processing said images, each image corresponding to a different charged particles' beam.
Claim 27
Dependent Claim
39 words
An electro-optical detector as described in claim 24 wherein said magnetic field at said focal plane is on the order of not less than 1000 gauss (G) and said angle is on the order of not less than 10°.
Claim 28
Dependent Claim
92 words
An electro-optical detector as described in claim 24 wherein said front and back ends of said array are parallel to one another, with said front end defined by the height and length of said array, forming said angle with said focal plane with the center of said front end along the array length being located in said focal plane, whereby the inlet ends of channels along said center lie in said focal plane with the inlet ends of channels above and below said center being either ahead or beyond said focal plane.
Claim 29
Dependent Claim
39 words
An electro-optical detector as described in claim 26 wherein said magnetic field at said focal plane is on the order of not less than 1000 gauss (G) and said angle is on the order of not less than 10°.
Claim 30
Dependent Claim
47 words
An electro-optical detector as described in claim 27 wherein said electron-sensitive means define a phosphorous surface substantially parallel to said back end and spaced apart therefrom, and said circuit means include means for accelerating said electrons exiting said array through said back end to said phosphorous surface.
Claim 31
Dependent Claim
40 words
An electro-optical detector as described in claim 24 wherein said back end forms said angle with respect to said front end and said array is wedge-shaped, with the front end of said array being located substantially at said focal plane.
Claim 32
Dependent Claim
39 words
An electro-optical detector as described in claim 29 wherein said magnetic field at said focal plane is on the order of not less than 1000 gauss (G) and said angle is on the order of not less than 10°.
Claim 33
Dependent Claim
58 words
An electro-optical detector as described in claim 30 wherein said electron-sensitive means define a phosphorous surface substantially parallel to said back end and spaced apart therefrom a distance on the order of not less than one millimeter, and said circuit means include means for accelerating said electrons exiting said array through said back end to said phosphorous surface.
Claim 34
Dependent Claim
26 words
An electro-optical detector as described in claim 24 wherein said means for processing comprise means for converting the images on said electron-sensitive means into electrical signals.
Claim 35
Dependent Claim
53 words
An electro-optical detector as described in claim 32 wherein said means for processing comprise vidicon means having a target exposable to images and means for converting the images on said target into related electrical signals, and means for transferring the images formed on said electron-sensitive means to the target of said vidicon means.
Claim 36
Dependent Claim
73 words
An electro-optical detector as described in claim 33 wherein said ion beams are focused at said focal plane at different locations along a first axis with the magnetic field at said focal plane being in a second axis perpendicular to said first axis, with the array length being disposed parallel to said first axis, with at least the center line in said front end along the array length being in said focal plane.
Claim 37
Dependent Claim
92 words
An electro-optical detector as described in claim 34 wherein said front and back ends of said array are parallel to one another, with said front end defined by the height and length of said array, forming said angle with said focal plane with the center of said front end along the array length being located in said focal plane, whereby the inlet ends of channels along said center lie in said focal plane with the inlet ends of channels above and below said center being either ahead or beyond said focal plane.
Claim 38
Dependent Claim
39 words
An electro-optical detector as described in claim 35 wherein said angle is on the order of not less than 10° and the magnetic field at said focal plane is on the order of not less than 1000 gauss (G).
Claim 39
Dependent Claim
40 words
An electro-optical detector as described in claim 34 wherein said back end forms said angle with respect to said front end and said array is wedge-shaped, with the front end of said array being located substantially at said focal plane.
Claim 40
Dependent Claim
39 words
An electro-optical detector as described in claim 37 wherein said angle is on the order of not less than 10° and the magnetic field at said focal plane is on the order of not less than 1000 gauss (G).
References Cited (Backward Citations)
US3777159A
Cited
US3809889A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-04 | 1979-11-03 | 1980-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-04 | 1983-11-03 | 1984-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-04 | 1987-11-03 | 1988-05-04 | $7700.00 | Window Closed / Lapsed |