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US 9,443,691 B2Granted
Electron emission surface for X-ray generation
AssigneeGeneral Electric Company
InventorsVance Scott Robinson, Carey Shawn Rogers, Sergio Lemaitre, Mark Alan Frontera, Sergiy Zalyubovskiy, Xi Zhang
Life of this patent
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Abstract
Embodiments of the disclosure relate to electron emitters for use in conjunction with X-ray emitting devices. In certain embodiments the emitter includes features that prevent, limit, or control deflection of the electron emitter at operating temperatures. In this manner, the electron emitter may be kept substantially flat or at a desired curvature during operation.
Claims20
An electron emitter comprising:
- a substrate having a first surface and a second surface opposite the first surface;
- a first coating deposited on the first surface, wherein the first coating has a lower work function than the substrate, wherein the first coating emits electrons when heated to an operating temperature of 2000° C. or greater, and wherein the first coating has a different coefficient of thermal expansion than the substrate;
- and
- a second coating deposited on the second surface, wherein the second coating also has a different coefficient of thermal expansion than the substrate;
- wherein expansion of the first coating and the second coating at the operating temperature of the electron emitter offset one another to substantially eliminate deflection of the electron emitter or to deflect the electron emitter to a controlled extent.
2 more elements
An electron emitter comprising:
- a substrate having a first surface and a second surface opposite the first surface;
- a coating deposited on the first surface, wherein the coating has a different coefficient of thermal expansion than the substrate;
- and
- one or more relief cuts extending at least partially through the coating and not extending entirely through the substrate.
1 more element
An electron emitter comprising:
- a substrate having a first surface and a second surface opposite the first surface;
- a first coating deposited on the first surface, wherein the first coating has a lower work function than the substrate and wherein the first coating has a different coefficient of thermal expansion than the substrate;
- a second coating deposited on the second surface, wherein the second coating also has a different coefficient of thermal expansion than the substrate;
- and
- one or more relief cuts extending at least partially through one of the first coating or the second coating and not extending entirely through the substrate.
2 more elements
An X-ray tube comprising:
- an electron beam source comprising an electron emitter configured to emit an electron beam, wherein the electron emitter comprises:
- a substrate having a first surface and a second surface opposite the first surface;
- a first coating deposited on the first surface, wherein the first coating has a lower work function than the substrate and wherein the first coating emits electrons when heated to an operating temperature of 2000° C. or greater, and wherein the first coating has a different coefficient of thermal expansion than the substrate;
- and
- a second coating deposited on the second surface, wherein the second coating also has a different coefficient of thermal expansion than the substrate and wherein the second coating has lower emissivity than the substrate during operation;
- an anode assembly configured to receive the electron beam and to emit X-rays when impacted by the electron beam;
- and
- a housing in which the electron beam source and the anode assembly are disposed.
5 more elements
Dependencies are inferred from the claim text.