X-ray source for materials analysis systems
AssigneeCarl Zeiss AG
InventorMark Dinsmore
Life of this patent
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Abstract
A miniaturized, increased efficiency x-ray source for materials analysis includes a laser source, an optical delivery structure, a laser-driven thermionic cathode (108), an anode (122), and a target from the laser source and directs the beam onto a surface of the themionic cathode. The surfaces electrons form an electron beam along a beam path. The target element (110) is disposed in the beam path, and emits x-rays in response to incident accelerated electrons from the thermionic cathode. The target element includes an inclined surface that forms an angle of inclination (113) of about 40 degrees with respect to the electon beam path, so that x-rays are emitted from the target substantially at an angle of about 45 degrees with respect to the electron beam path.
Claims26
A x-ray source for materials analysis, comprising:
- A. an optical delivery structure;
- B. an optical source, including means for generating a beam of optical radiation directed to said optical delivery structure;
- C. an x-ray generator assembly in optical communication with said optical delivery structure, said x-ray generator assembly including:
- a. an electron source, responsive to incident optical radiation for generating an electron beam along a beam path, said electron source comprising a thermionic cathode having an electron emissive surface;
- and
- b. a target element positioned in said beam path, said target element including at least one x-ray emissive material adapted to emit x-rays in response to incident accelerated electrons from said electron source, said target element having an inclined surface defining an angle of inclination with respect to said beam path;
- and
- D. means for providing an accelerating voltage between said electron source and said target element so as to establish an accelerating electric field which acts to accelerate electrons emitted from said electron source toward said target element;
- wherein said optical delivery structure is adapted to direct a beam of optical radiation transmitted therethrough to impinge upon a surface of said thermionic cathode, and
- wherein said beam of transmitted optical radiation has a power level sufficient to heat at least a portion of said surface to an electron emitting temperature so as to cause thermionic emission of electrons from said surface.
A substantially rigid capsule formed of a dielectric material and containing an electron source, an anode, and a sealing structure, said capsule defining a substantially evacuated interior region extending along a beam axis between said electron source and said anode;
- wherein said sealing structure is adapted to affix said anode to said capsule;
- and
- wherein said sealing structure is formed of a material having a relatively low melting point relative to said dielectric material forming said capsule, and having substantially the same temperature coefficient as said dielectric material.
Dependencies are inferred from the claim text.