Radiation source, imaging system, and operating method to determine and produce a radiation focal spot having an asymmetrical power input profile

A radiological imaging system comprising:

• a radiation source comprising an electron emitter that emits electrons in an electron beam, a rotating anode struck by said electrons in said electron beam at a focal spot on a surface of the rotating anode, at which x-rays are generated and emitted, said rotating anode rotating in a movement direction, and beam modifying structure that interacts with said electrons in said x-ray beam to modify said x-ray beam to produce an asymmetrical power input profile of said focal spot parallel to said movement direction of the rotating anode;
• an x-ray detector on which said x-rays emitted from said x-ray source are incident;
• and
• a supporting arrangement that supports said radiation source and said x-ray detector at a distance from each other.

A method for operating a radiation source comprising the steps of:

• emitting electrons in an electron beam from an electron emitter;
• placing a rotating anode in said electron beam and striking said rotating anode with said electrons at a focal spot on a surface of the rotating anode to generate and emit x-rays from said focal spot;
• rotating said rotating anode in a movement direction during emission of said x-rays from said focal spot;
• and
• modifying said electrons in said electron beam to give said focal spot an asymmetrical power input profile in said movement direction of said rotating anode.

A method to determine an asymmetrical power input profile of a focal spot on a rotating anode in a radiation source, said focal spot being produced by electrons striking said rotating anode with a spatially dependent power input, and said rotating anode having a spatially dependent temperature with a time curve dependent on said spatially dependent power input, and said rotating anode having a spatially dependent heat dissipation for a predetermined rotation frequency of the rotating anode, and said rotating anode being comprised of anode material having material properties, and wherein said radiation source is used in an imaging system to produce an image having boundary conditions that define an image quality of the image, said method comprising the steps of:

• providing a computerized processor with input information representing at least one of said spatially dependent power input, said time curve of said spatially dependent temperature, said spatially dependent heat dissipation, said predetermined rotation frequency, said material properties, and said boundary conditions;
• in said computerized processor, executing an optimization method employing an equation embodying said input information to determine, as a result of executing said optimization method, and a symmetrical power input profile of said focal spot parallel to said movement direction of said rotating anode;
• and
• making a representation of said asymmetrical power input profile of said focal spot parallel to said movement direction available at an output of said processor.