Patent US3594885A successfully refreshed from Google Patents.
US3594885A
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Method for fabricating a dimpled concave dispenser cathode incorporating a grid
Assignee: Varian Medical Systems Inc
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Filing: 1969-06-16
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Granted: 1971-07-27
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Expires: 1989-06-16
Abstract
Abstract Methods for fabricating concave dimpled dispenser cathodes are disclosed. A multicell groove pattern is formed in the concave face of the cathode blank. An array of concave dimples are formed in the cellular regions of the concave emitter face bounded by the cells of the groove pattern. A multicell grid structure is incorporated into the groove pattern. The groove pattern is formable by photoetching, electrical discharge machining or by milling. The grid structure may be brazed into the grooves or merely supported therein in noncontacting relation therewith.
Inventors
- 👤 George V Miram
- 👤 Gerhard B Kuehne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:01
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/02; H01J9/04; H01J9/042; H01J9/047
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
128 words
In a method for fabricating a dimpled dispenser cathode for a convergent stream electron gun the steps of, forming a multicell groove pattern in the concave face of a dispenser cathode blank, such multicell groove pattern conforming generally to the web pattern of a multiapertured control grid to be employed over the concave emissive surface of the dispenser cathode, forming an array of concave dimpled emissive facets in the concave face of the cathode blank, each of the individual facets being located such as to be bounded by an individual cell of the multicell groove pattern, and incorporating a multiapertured grid structure in the groove pattern, such grid structure having a web pattern conforming generally to the groove pattern and to the web pattern of the control grid.
Claim 2
Dependent Claim
128 words
In a method for fabricating a dimpled dispenser cathode for a convergent stream electron gun the steps of, forming a multicell groove pattern in the concave face of a dispenser cathode blank, such multicell groove pattern conforming generally to the web pattern of a multiapertured control grid to be employed over the concave emissive surface of the dispenser cathode, forming an array of concave dimpled emissive facets in the concave face of the cathode blank, each of the individual facets being located such as to be bounded by an individual cell of the multicell groove pattern, and incorporating a multiapertured grid structure in the groove pattern, such grid structure having a web pattern conforming generally to the groove pattern and to the web pattern of the control grid.
Claim 3
Dependent Claim
55 words
The method of claim 1 wherein the step of forming the multicelled groove pattern in the concave face of the dispenser cathode blank comprises the step of marking the concave face to be grooved to indicate the pattern of the desired grooves, and milling the grooves in the concave face according to the marked pattern.
Claim 4
Dependent Claim
65 words
The method of claim 1 wherein the step of forming the multicelled groove pattern in the concave face of the dispenser cathode blank comprises the step of electrically discharge machining the concave face with a tool having a discharge defining electrode pattern conforming to at least a portion of the desired groove pattern to be formed in the concave face of the dispenser cathode blank.
Claim 5
Dependent Claim
41 words
The method of claim 1 wherein the step of forming the multicelled groove pattern in the concave face of the dispenser cathode blank comprises the step of, chemically etching the groove pattern in the concave face of the dispenser cathode blank.
Claim 6
Dependent Claim
69 words
The method of claim 1 wherein the cathode blank into which the groove pattern is to be formed comprises a porous tungsten body with the pores infiltrated with a malleable material, and including the steps of removing the malleable material from the grooved cathode blank to leave a porous metal blank, and infiltrating the pores of the metal blank with electron emissive material to form a dispenser cathode body.
Claim 7
Dependent Claim
42 words
The method of claim 5 wherein the step of incorporating the grid structure into the groove pattern includes the steps of, locating the web of the grid structure in the groove pattern, and brazinG the grid structure to the grooved cathode body.
Claim 8
Dependent Claim
29 words
The method of claim 5 including the step of, coating the grid structure to be incorporated in the groove pattern of the dispenser cathode blank with an electron-emission-inhibiting coating.
Claim 9
Dependent Claim
101 words
The method of claim 4 wherein the step of chemically etching the groove pattern includes the steps of, positioning a masking grid structure, having the desired grid pattern to be formed in the cathode, adjacent the concave face of the cathode blank, coating the grid structure and exposed positions of the masked concave face of the cathode blank with an acid-resistant emulsion, removing the masking grid structure to expose the surface of the cathode blank masked by the masking grid structure, and chemically etching the exposed surfaces in the concave face of the cathode blank to form the desired groove pattern.
Claim 10
Dependent Claim
24 words
The method of claIm 1 wherein the individual cell pattern of the grooves formed in the concave face of the cathode blank is hexagonal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-26 | 1975-01-25 | 1975-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-26 | 1979-01-25 | 1979-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-26 | 1983-01-25 | 1983-07-27 | $7700.00 | Window Closed / Lapsed |