X-ray tube having reduced window heating
AssigneeGeneral Electric Company
InventorLembit Salasoo
Life of this patent
Estimating the term…
Abstract
An X-ray tube assembly having a cathode, an anode, and an electrode surrounded by a vacuum-enclosing frame. Electrons from the cathode strike a target surface on the anode. Some electrons produce X-rays which exit an X-ray transparent window portion of the frame. Other electrons are backscattered and go on to strike and heat the frame including the window region. The non-electron-emifting electrode typically has a negative electrical potential and is positioned to deflect the backscattered electrons away from the window region which reduces heating thereto and hence minimizes tube failure.
Claims13
An X-ray tube assembly comprising:
- a) an X-ray tube cathode having a first electrical potential and including an electron emitting surface having an electron beam axis;
- b) an X-ray tube anode spaced apart from said cathode, having a second electrical potential which is more positive than said first electrical potential, and including an X-ray target surface generally facing said electron emitting surface of said cathode and intersecting said electron beam axis at a focal point;
- c) a generally-hermetically-sealed frame surrounding said cathode and said anode, spaced apart from said electron emitting surface and said X-ray target surface, and including an essentially-X-ray-transparent window having a perimeter and a point center of mass, wherein said focal point and said point center of mass define an X-ray beam centerline;
- and
- d) a generally-non-electron-emitting electrode disposed within said frame, spaced apart from said electron emitting surface and said X-ray target surface and said window, and having a third electrical potential which is more negative than said second electrical potential,
- wherein said X-ray tube assembly is devoid of any electrode disposed within said frame, other than said anode, which attracts electrons.
An X-ray tube assembly comprising:
- a) an X-ray tube cathode having a first electrical potential and including an electron emitting surface having an electron beam axis;
- b) an X-ray tube anode spaced apart from said cathode, having a second electrical potential which is more positive than said first electrical potential, and including an X-ray target surface generally facing said electron emitting surface of said cathode and intersecting said electron beam axis at a focal point;
- c) a generally-hermetically-sealed glass frame surrounding said cathode and said anode, spaced apart from said electron emitting surface and said X-ray target surface, and including an essentially-X-ray-transparent window having a perimeter and a point center of mass, wherein said focal point and said point center of mass define an X-ray beam centerline;
- d) a casing surrounding and generally spaced apart from said frame;
- e) a dielectric liquid coolant disposed between said frame and said casing;
- and
- f) a generally-non-electron-emitting electrode disposed between said frame and said casing, and having a third electrical potential which is more negative than said second electrical potential,
- wherein said X-ray tube assembly is devoid of any electrode disposed between said frame and said casing which attracts electrons.
Dependencies are inferred from the claim text.