X-ray tube and anode target
View Patent ↗According to one embodiment, an X-ray tube including an electron emission source which emits an electron, an anode target which comprises a target layer emitting an X-ray by the electron from the electron emission source, and a substrate supporting the target layer and composed from a carbide-strengthened molybdenum alloy, an evacuated outer surrounding envelope which contains the electron emission source and the anode target, a diffusion barrier layer which is integrally formed with the substrate by a powder metallurgy method on a part of a top surface of the substrate and is composed of a high-melting-point metal lacking of carbon-element content compared with carbon-element content in the substrate, and a thermal radiation film which is formed on at least a part of a top surface of the diffusion barrier layer and composed of metallic oxide.
1. An X-ray tube comprising:
an electron emission source which emits an electron;
an anode target which comprises a target layer emitting an X-ray by the electron from the electron emission source, and a substrate supporting the target layer and composed of a carbide-strengthened molybdenum alloy;
an evacuated outer surrounding envelope which contains the electron emission source and the anode target;
a diffusion barrier layer which is integrally formed with the substrate by a powder metallurgy method on a part of a top surface of the substrate and is composed of a high-melting-point metal lacking of carbon-element content compared with carbon-element content in the substrate; and
a thermal radiation film which is formed on at least a part of a top surface of the diffusion barrier layer and composed of metallic oxide.
2. The X-ray tube of claim 1 , wherein the diffusion barrier layer prevents a carbon-element component contained in the substrate from reaching the thermal radiation film.
3. The X-ray tube of claim 2 , wherein the diffusion barrier layer is integrally formed with the substrate and the target layer by the powder metallurgy method.
4. The X-ray tube of claim 2 , wherein a shortest distance from the top surface of the diffusion barrier layer to the substrate is greater than or equal to 1 mm.
5. The X-ray tube of claim 2 , wherein the diffusion barrier layer is pure molybdenum whose contained mass of carbon-element is less than 0.005% by weight.
6. The X-ray tube of claim 1 , wherein the diffusion barrier layer is integrally formed with the substrate and the target layer by the powder metallurgy method.
7. The X-ray tube of claim 6 , wherein a shortest distance from the top surface of the diffusion barrier layer to the substrate is greater than or equal to 1 mm.
8. The X-ray tube of claim 6 , wherein the diffusion barrier layer is pure molybdenum whose contained mass of carbon-element is less than 0.005% by weight.
9. The X-ray tube of claim 1 , wherein a shortest distance from the top surface of the diffusion barrier layer to the substrate is greater than or equal to 1 mm.
10. The X-ray tube of claim 9 , wherein the diffusion barrier layer is pure molybdenum whose contained mass of carbon-element is less than 0.005% by weight.
11. The X-ray tube of claim 1 , wherein the diffusion barrier layer is pure molybdenum whose contained mass of carbon-element is less than 0.005% by weight.
12. An anode target comprising a target layer which emits an X-ray by an electron from an electron emission source, and a substrate which supports the target layer and is composed from a carbide-strengthened molybdenum alloy, the anode target comprising:
a diffusion barrier layer which is integrally formed with the substrate by a powder metallurgy method on a part of a top surface of the substrate and is composed of a high-melting-point metal lacking of carbon-element content compared with carbon-element content in the substrate; and
a thermal radiation film which is formed of metallic oxide and is formed on at least a part of a top surface of the diffusion barrier layer.
13. The anode target of claim 12 , wherein the diffusion barrier layer is integrally formed with the substrate and the target layer by the powder metallurgy method.
14. The anode target of claim 13 , wherein a shortest distance from the top surface of the diffusion barrier layer to the substrate is greater than or equal to 1 mm.
15. The anode target of claim 13 , wherein the diffusion barrier layer is pure molybdenum whose contained mass of carbon-element is less than 0.005% by weight.
16. The anode target of claim 12 , wherein a shortest distance from the top surface of the diffusion barrier layer to the substrate is greater than or equal to 1 mm.
17. The anode target of claim 16 , wherein the diffusion barrier layer is pure molybdenum whose contained mass of carbon-element is less than 0.005% by weight.
18. The anode target of claim 12 , wherein the diffusion barrier layer is pure molybdenum whose contained mass of carbon-element is less than 0.005% by weight.