Patent Number: 
Section: claims

1. An X-ray optical element for reflection of a cross-sectionally reflected X-ray radiation in two dimensions, comprising:a first reflective, curved surface;a second reflective, curved surface adjacent to the first element at a joint angle; andan X-ray beam source producing the X-ray radiation directed onto the first and second reflective surfaces, the X-ray radiation being reflected from one of the first and second surfaces onto the other surface, the first surface curved at a first angle different than a second angle at which the second surface is curved, the first surface exhibiting a first focal length different than a second focal length that the second surface exhibits. 2. The X-ray optical element according to claim 1, wherein the joint angle is 90°. 3. The X-ray optical element according to claim 1, wherein the joint angle is less than 90°. 4. The X-ray optical element according to claim 1, wherein the first and second reflective surfaces are curved one of parabolically, elliptically, and a combination thereof. 5. The X-ray optical element according to claim 1, wherein the first and second reflective surfaces are formed with multilayer systems having graded layer thicknesses. 6. The X-ray optical element according claim 5, wherein the layer depths of one of the multilayer systems is graded. 7. The X-ray optical element according to claim 1, wherein the X-ray radiation is directed and reflected onto the first and second surfaces in compliance with a Bragg condition. 8. The X-ray optical element according to claim 1, wherein the first and second focal lengths have respective focal points are arranged within a focal point volume. 9. The X-ray optical element according to claim 1, wherein the X-ray beam source is located prior to the first and second reflective surfaces so that the X-ray radiation forms a tetraeder. 10. A method for at least one of local and temporal influencing of at least one of a homogeneity, an energy/photon density over a cross section, a form of the cross section, an area of the cross section, a divergence for an X-ray radiation, comprising:directing the X-ray radiation to a first and second reflective, curved surfaces, the first and second surfaces adjacent to one another at a joint angle; andreflecting the X-ray radiation from one of the first and second surfaces onto the other surface, the first surface curved at a first angle different than a second angle at which the second surface is curved, the first surface exhibiting a first focal length different than a second focal length that the second surface exhibits.