High aspect ratio x-ray targets and uses of same
View Patent ↗An x-ray target, a method of using the x-ray target, and a computer program product with instructions for carrying out a method of using the x-ray target. The x-ray target includes a substrate made from a soft x-ray producing material and a high aspect ratio structure made from a hard x-ray producing material. The hard x-ray producing material is embedded in the substrate, formed on the substrate, cantilevered out from the edge of the substrate, or any combination thereof. The high aspect ratio structure comprises a plurality of high aspect ratio structures arranged in one or more grids or arrays, and the high aspect ratio structures in one of the one or more grids or arrays are arranged to form a Hadamard matrix structure.
1. A method for generating an x-ray image of a sample, comprising:
sequentially focusing an electron beam on each of a plurality of orthogonal Hadamard matrix structures, each orthogonal Hadamard matrix structure made from a plurality of high aspect ratio structures arranged at different pixel locations in a pixilated grid pattern, each high aspect ratio structure made from a hard x-ray producing material;
illuminating the sample with x-rays produced by sequentially focusing the electron beam on each of the plurality of orthogonal Hadamard matrix structures;
sequentially detecting the x-rays transmitted through the sample, and recording the detected x-rays in a plurality of Hadamard transformed x-ray images;
applying one or more inverse Hadamard transforms to the plurality of Hadamard transformed x-ray images to generate one or more x-ray images, wherein each of the one or more x-ray images is generated from an inverse Hadamard transform corresponding to a different pixel in the pixilated grid of high aspect ratio structures that make up the orthogonal Hadamard matrix structures; and
combining the one or more x-ray images to generate an x-ray image of the sample.
2. The method of claim 1 , wherein each of the orthogonal Hadamard matrix structures is located at a different location on the same x-ray target.
3. The method of claim 2 , further comprising determining the location of each of the plurality of orthogonal Hadamard matrix structures on the x-ray target before sequentially focusing the electron beam on each of the plurality of orthogonal Hadamard matrix structures.
4. The method of claim 2 , wherein applying the one or more inverse Hadamard transforms includes correcting for relative parallax in each of the Hadamard transformed x-ray images due to the different locations of the orthogonal Hadamard matrix structures on the x-ray target.
5. The method of claim 4 , wherein combining the x-ray images includes correcting for relative parallax in each of the x-ray images due to the different pixel locations of the high aspect ratio structures in each of the orthogonal Hadamard matrix structures.
6. The method of claim 1 , wherein at least two high aspect ratio structures in each of the plurality of orthogonal Hadamard matrix structures are made from different hard x-ray producing materials, such that the spatial distribution of the at least two high aspect ratio structures made from the different hard x-ray producing materials is the same in each of the plurality of orthogonal Hadamard matrix structures.
7. The method of claim 6 , wherein combining the one or more x-ray images includes combining x-ray images corresponding to pixels in the orthogonal Hadamard matrix structures having high aspect ratio structures made from the same hard x-ray producing material.
8. The method of claim 1 , wherein applying one or more inverse Hadamard transforms to the plurality of Hadamard transformed x-ray images to generate one or more x-ray images comprises adding or subtracting the plurality of Hadamard transformed x-ray images based on a Hadamard code.
9. The method of claim 1 , wherein the plurality of orthogonal Hadamard matrix structures are made from a plurality of high aspect ratio structures made from a first hard x-ray producing material, further comprising:
sequentially focusing the electron beam on each of a second plurality of orthogonal Hadamard matrix structures, each made from a plurality of high aspect ratio structures made from a second hard x-ray producing material;
illuminating the sample with the x-rays produced by sequentially focusing the electron beam on each of the second plurality of orthogonal Hadamard matrix structures;
sequentially detecting the x-rays transmitted through the sample, and recording the detected x-rays in a second plurality of Hadamard transformed x-ray images;
applying one or more inverse Hadamard transforms to the second plurality of Hadamard transformed x-ray images to generate one or more x-ray images for the second hard x-ray producing material, wherein each of the one or more x-ray images for the second hard x-ray producing material is generated from an inverse Hadamard transform corresponding to a different pixel; and
combining the one or more x-ray images for the second hard x-ray producing material to generate an x-ray image of the sample for the second hard x-ray producing material.
10. The method of claim 1 , wherein the plurality of orthogonal Hadamard matrix structures are made from a plurality of high aspect ratio structures having a first cross sectional area, further comprising:
sequentially focusing the electron beam on each of a second plurality of orthogonal Hadamard matrix structures, each made from a plurality of high aspect ratio structures having a second cross-sectional area;
illuminating the sample with the x-rays produced by sequentially focusing the electron beam on each of the second plurality of orthogonal Hadamard matrix structures;
sequentially detecting the x-rays transmitted through the sample, and recording the detected x-rays in a second plurality of Hadamard transformed x-ray images;
applying one or more inverse Hadamard transforms to the second plurality of Hadamard transformed x-ray images to generate one or more higher resolution x-ray images, wherein each of the one or more higher resolution x-ray images is generated from an inverse Hadamard transform corresponding to a different pixel; and
combining the one or more higher resolution x-ray images to generate a higher resolution x-ray image of the sample.
11. A computer program product, embedded on a non-transitory medium, comprising instructions operable to cause a programmable processor to:
sequentially focus an electron beam on each of a plurality of orthogonal Hadamard matrix structures, each Hadamard matrix structure made from a plurality of high aspect ratio structures arranged at different pixel locations in a pixilated grid pattern, each high aspect ratio structure made from a hard x-ray producing material;
sequentially detect x-rays produced by the plurality of orthogonal Hadamard matrix structures and transmitted through a sample, and record the detected x-rays in a plurality of Hadamard transformed x-ray images;
apply one or more inverse Hadamard transforms to the plurality of Hadamard transformed x-ray images to generate one or more x-ray images, wherein each of the one or more x-ray images is generated from an inverse Hadamard transform corresponding to a different pixel in the pixilated grid of high aspect ratio structures that make up the orthogonal Hadamard matrix structures; and
combine the one or more x-ray images to generate an x-ray image of the sample.