Patent Number: 
Section: claims

1. A collimator for exposing a specimen to an X-ray field, wherein the X-ray field is in the submicrometer to micrometer range, comprising:a first structure comprising a first planar surface and a second planar surface, wherein said first planar surface comprises one or more grooves; anda second structure having a first planar surface and a second planar surface, wherein said first planar surface on said second structure optionally comprises one or more grooves;wherein said first planar surface of said first structure is in contact with said second planar surface of said second structure such that said second structure covers over the one or more grooves on said first structure through which X-rays penetrate to produce the X-ray field or fields, wherein the groove has a smallest dimension that is in the submicrometer to micrometer range. 2. The collimator of claim 1, wherein the X-ray fields are 0.5-50 micrometers in one dimension and 0.5 micrometers to 3 millimeters in the other direction. 3. The collimator of claim 1, wherein the X-ray fields are 0.5-10 micrometers in one dimension and 0.5 micrometers to 3 millimeters in the other direction. 4. The collimator of claim 1, wherein the X-ray fields are 0.5-2 micrometers in one dimension and 0.5 micrometers to 3 millimeters in the other direction. 5. The collimator of claim 1, wherein said structures are 1-2 centimeters long, 1-2 centimeter wide and 25-400 micrometers thick. 6. The collimator of claim 1 wherein said structure is Silicon. 7. The collimator of claim 1 wherein said structure is gallium arsenide. 8. The collimator of claim 1 wherein said structure is a semiconducting material, a ceramic material, a metallic material, a semi-metal, an alloy, a glass or combinations thereof. 9. The collimator of claim 1 wherein said structures are coated with a SiO2 surface layer, whose etching results in the grooves, through which the X-rays penetrate through the collimator. 10. The collimator of claim 1 wherein at least two plates with grooves are stacked against each other to produce multiple X-ray fields. 11. The collimator of claim 1 further comprising a third structure comprising a first planar surface and a second planar surface, wherein said first planar surface of said third structure optionally comprises one or more grooves; wherein said second structure of said third plate is in contact with said first planar surface of said second structure. 12. The collimator of claim 1, wherein said one or more grooves of each structure is about 0.5-100, 0.5-50, 0.5-10, or 0.5-2 micrometers in depth. 13. The collimator of claim 1, wherein said one or more grooves of each structure is about 0.5 micrometers to 3 millimeters in width. 14. An apparatus comprising a collimator holder and a collimator of claim 1, wherein said holder comprises a first plate and a second plate. 15. The apparatus of claim 14, wherein said collimator holder further comprises a specimen holder. 16. The apparatus of claim 14, wherein the said first and second plate of said collimator holder are contained within a second holder wherein said second holder comprises a third plate and fourth plate, wherein said third and fourth plate comprises a force member allowing the first and second plate to be under pressure. 17. The apparatus of claim 14, further comprising an alignment apparatus. 18. The apparatus of claim 17, wherein said alignment apparatus rotates said holder along an axis that is perpendicular to an X-ray beam axis. 19. The apparatus of claim 17, wherein said alignment apparatus rotates said holder perpendicular to a shortest edge of the produced X-ray field. 20. The apparatus of claim 17, wherein said alignment apparatus comprises a motor. 21. The apparatus of claim 14 further comprising an X-ray source. 22. The collimator of claim 1, wherein said one or more grooves of each structure is 0.5-100 micrometers in depth. 23. The collimator of claim 1, wherein said one or more grooves of each structure is 0.5-50 micrometers in depth. 24. The collimator of claim 1, wherein said one or more grooves of each structure is 0.5-10 micrometers in depth. 25. The collimator of claim 1, wherein said one or more grooves of each structure is 0.5-2 micrometers in depth.