X-ray tube assembly and X-ray CT equipment
A lightweight X-ray tube assembly and X-ray CT equipment having the same. The X-ray tube assembly includes an X-ray tube and a tube housing. The X-ray tube includes: a cathode for generating an electron beam; an anode for radiating X rays by collision of the electron beam; an envelope for holding the cathode and the anode in a vacuum atmosphere; and an X-ray window provided in the envelope to irradiate some of X rays radiated from the anode toward a test subject. The tube housing encapsulates the X-ray tube together with an insulating oil. The X-ray tube assembly further includes a protective member that is provided at least around the X-ray window on an outer wall of the envelope and shields the X rays.
1 . An X-ray tube assembly comprising:
an X-ray tube that includes:
a cathode for generating an electron beam;
an anode for radiating X rays by collision of the electron beam;
an envelope for holding the cathode and the anode in a vacuum atmosphere; and
an X-ray window provided in the envelope to irradiate some of the X rays radiated from the anode toward a test subject;
a tube housing for encapsulating the X-ray tube together with an insulating oil; and
a protective member that is provided at least around the X-ray window on an outer wall of the envelope and shields the X rays, wherein
the protective member has a flow passage in which the insulating oil flows, and the flow passage is a hole to lead the insulating oil to a surface of the X-ray window, and
the protective member has a cylindrical shape to cover a circumference of the X-ray window, and the hole is located so as to make the insulating oil swirl along an inside surface of the protective member.
2 . The X-ray tube assembly according to claim 1 , wherein the hole is inclined with respect to the X-ray window so as to lead the insulating oil to a surface opposite to an area where electrons emitted from the anode collide against the X-ray window.
3 . The X-ray tube assembly according to claim 2 , further comprising a slope to lead the insulating oil to the hole.
4 . The X-ray tube assembly according to claim 1 , wherein minute concaves and convexes are formed on the inside surface of the protective member.
5 . The X-ray tube assembly according to claim 1 , wherein the flow passage is a groove for the insulating oil to flow between an outer wall of the envelope and the protective member.
6 . X-ray CT equipment that generates a tomographic image of a test subject and comprises the X-ray tube assembly according to claim 1 .
7 . An X-ray tube assembly comprising:
an X-ray tube that includes:
a cathode for generating an electron beam;
an anode for radiating X rays by collision of the electron beam;
an envelope for holding the cathode and the anode in a vacuum atmosphere; and
an X-ray window provided in the envelope to irradiate some of the X rays radiated from the anode toward a test subject;
a tube housing for encapsulating the X-ray tube together with an insulating oil; and
a protective member that is provided at least around the X-ray window on an outer wall of the envelope and shields the X rays,
wherein a dimple is formed on an outside surface of the X-ray window, and the outside surface is parallel to the X rays that irradiate the test subject.
8 . X-ray CT equipment configured to generate a tomographic image of a test subject, the X-ray CT equipment comprising the X-ray tube assembly according to claim 7 .
9 . The X-ray tube assembly according to claim 7 , wherein the protective member has a flow passage in which the insulating oil flows.
10 . The X-ray tube assembly according to claim 9 , wherein the flow passage is a hole to lead the insulating oil to a surface of the X-ray window.
11 . The X-ray tube assembly according to claim 10 , wherein the hole is inclined with respect to the X-ray window so as to lead the insulating oil to a surface opposite to an area where electrons emitted from the anode collide against the X-ray window.
12 . The X-ray tube assembly according to claim 10 , further comprising a slope to lead the insulating oil to the hole.
13 . The X-ray tube assembly according to claim 10 , wherein
the protective member has a cylindrical shape to cover a circumference of the X ray window, and
the hole is located so as to make the insulating oil swirl along an inside surface of the protective member.
14 . The X-ray tube assembly according to claim 13 , wherein minute concave and convex portions are formed on the inside surface of the protective member.
15 . The X-ray tube assembly according to claim 9 , wherein the flow passage is a groove for the insulating oil to flow between an outer wall of the envelope and the protective member.