Patent US3885194A successfully refreshed from Google Patents.
US3885194A
Expired / Lapsed
US
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Temperature control for an indirectly heated cathode for a high power electron beam gun
Assignee: Westinghouse Electric Corp
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Filing: 1973-04-30
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Granted: 1975-05-20
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Expires: 1993-04-30
Abstract
Abstract A method and apparatus for regulating and determining the temperature of a heated cathode in an electron beam system to regulate the magnitude of the beam current both during operation and prior to turn on. This is accomplished by measuring the thermionic emission of a well defined area of the cathode, regardless of whether the electron beam is being drawn from the cathode, and utilizing this measured signal to control the temperature of the heated cathode.
Inventors
- 👤 Berthold W Schumacher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:44
CPC Classifications
G; G05; G05F; G05F1/00; G05F1/10; G05F1/46; H; H01; H01J; H01J37/00; H01J37/02; H01J37/04; H01J37/06; H01J37/24; H01J37/242
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
158 words
In combination with an electron gun for generating a high power electron beam, which electron gun includes an elongated cathode member and cathode heater means associated therewith for electron bombardment heating of the cathode member, with the electron beam being drawn from one end of said cathode member, and wherein the temperature of the cathode member significantly affects the electron beam emission, the improvement comprising a ring conductive electrode disposed about the cathode member at a location spaced from the electron beam emission end portion of the cathode member, with a secondary emitted electron current flow produced between said cathode member and said ring conductive electrode, a shielding enclosure disposed about the ring conductive electrode with the cathode member passing through the shielding enclosure, and sensing means electrically connected to the ring conductive electrode for measuring the secondary emitted electron current and indicating the temperature of the cathode member as a function of said secondary emitted electron current.
Claim 2
Dependent Claim
158 words
In combination with an electron gun for generating a high power electron beam, which electron gun includes an elongated cathode member and cathode heater means associated therewith for electron bombardment heating of the cathode member, with the electron beam being drawn from one end of said cathode member, and wherein the temperature of the cathode member significantly affects the electron beam emission, the improvement comprising a ring conductive electrode disposed about the cathode member at a location spaced from the electron beam emission end portion of the cathode member, with a secondary emitted electron current flow produced between said cathode member and said ring conductive electrode, a shielding enclosure disposed about the ring conductive electrode with the cathode member passing through the shielding enclosure, and sensing means electrically connected to the ring conductive electrode for measuring the secondary emitted electron current and indicating the temperature of the cathode member as a function of said secondary emitted electron current.
Claim 3
Dependent Claim
53 words
The combination specified in claim 1, wherein the sensing means generates a signal which is a function of the cathode member temperature, and the sensing means is connected to the cathode heating means, whereby the generated signal is fed back to the cathode heating means to control the temperature of the cathode member.
Claim 4
Dependent Claim
64 words
The combination specified in claim 1 wherein the electron gun is disposed within a partially evacuated electron beam generating chamber of a high power electron beam system, and wherein said sensing means and control signal means associated with the electron gun are operative to sense said electron emission capability of the cathode of said gun with or without flow of the electron beam current.
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) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |