Patent Number: 
Section: claims

1. An x-ray imaging configuration, comprising: means to support a sample; and  a body of a substance excitable by an appropriate incident beam to generate x-ray radiation, the body being arranged with respect to said sample support means so that said radiation irradiates said sample;  wherein said body is a divided or patterned array of spaced apart body portions, each of which, when excited by said incident beam, generates an x-ray beam of accurately predictable source size. 2. An x-ray imaging configuration according to  claim 1 , wherein said substance is excitable by an electron beam to generate x-ray radiation. claim 1 3. An x-ray imaging configuration according to  claim 1 , wherein said substance is excitable by an incident focused beam of electromagnetic radiation to generate x-ray radiation. claim 1 4. An x-ray imaging configuration according to  claim 1 , wherein said body portions are retained on a common substrate. claim 1 5. An x-ray imaging configuration according to  claim 1 , further comprising an energy detector. claim 1 6. An x-ray imaging configuration according to  claim 1 , wherein said body portions are about 0.21 xcexcm in width. claim 1 7. An x-ray microscope or microprobe comprising: means to generate an electron beam;  means to support a sample; and  a body of a substance excitable by said electron beam to generate x-ray radiation, the body being arranged with respect to said sample support means so that said radiation irradiates said sample;  wherein said body is a divided or patterned array of body portions, each of which, when excited by said electron beam, generates an x-ray beam of accurately predictable source size. 8. An x-ray microscope or microprobe according to  claim 7 , wherein said body portions are about 0.2 xcexcm in width. claim 7 9. An x-ray microscope or microprobe according to  claim 7 , wherein the electron beam is focused in operation to a width in the range of 10 to 1000 nm in said body of excitable substance. claim 7 10. An x-ray microscope or microprobe according to  claim 7 , wherein said body portions are retained on a common substrate. claim 7 11. An x-ray microscope or microprobe according to  claim 7 , further including an energy detector. claim 7 12. An apparatus for irradiating a sample with x-ray radiation for imaging the sample, comprising: a sample holder for mounting a sample; and  a substance excitable by an appropriate incident beam to generate x-ray radiation, the substance being disposed in spaced relationship with said sample holder, such that x-ray radiation generated from said substance irradiates the sample mounted to said sample holder, and thereafter exits the sample holder for detection external to the sample holder, wherein said sample holder and said substance are adapted and dimensioned to be inserted in a complementary holder of an electron microscope at a position where the electron beam of the microscope is focused on said substance, to thereby generate x-ray radiation. 13. The apparatus according to  claim 12  wherein said substance is excitable by an incident focused beam of electromagnetic radiation to generate x-ray radiation. claim 12 14. The apparatus according to  claim 12  wherein said substance comprises a patterned array of x-ray generating material retained on a common substrate. claim 12 15. The apparatus according to  claim 12  wherein said sample holder comprises a chamber arranged to be hermetically sealed after placement of a sample in the chamber. claim 12 16. The apparatus according to  claim 12  wherein said sample holder is adapted to be enclosed, and said sample holder includes an x-ray transparent window by which the said x-ray radiation exits the sample holder for detection. claim 12 17. The apparatus according to  claim 12 , further comprising an energy detector disposed in spaced relationship with said sample holder external to said sample holder. claim 12 18. A method for irradiating a sample with x-ray radiation for imaging the sample, comprising: disposing the sample in a sample holder in spaced relationship with a substance excitable by an appropriate incident beam to generate x-ray radiation and inserting the sample holder and said substance in a complementary holder of an electron microscope at a position where the electron beam of the microscope is focused on said substance; and  irradiating said substance with an electron beam to cause the substance to generate x-ray radiation to irradiate the sample for detection external to the sample holder. 19. The method of  claim 18 , further comprising the step of: claim 18 detecting at least a portion of the radiation exiting the sample holder after it has irradiated the sample, to provide an image of one or more internal boundaries or other features of the sample.