X-ray source and X-ray system

A mammography system comprising:

• an x-ray source comprising a housing, a plurality of electron sources in said housing, said electron sources being spaced apart from each other along a longitudinal direction, a single anode operable in common with all of said electron sources, said anode being mounted in said housing for rotation around a rotation axis that is parallel to and defines said longitudinal direction, said anode body being a composite comprising a base body and a cover layer over said base body, said cover layer being comprised of anode material that interacts with said electrons to emit x-rays, said base body and said cover layer being respectively comprised of different material compositions, said cover layer being subdivided into a plurality of segments each proceeding around a periphery of said anode body, said segments being spatially spaced apart from each other along said longitudinal direction each having respective emission spectrum, and each of said electron source emitting electrons that strike only a location in a respective one of said segments on said anode that are spatially separated from each other along said longitudinal direction, the respective locations forming separate emission centers, each emission center being individually associated with one of said electron sources, and each emission center emitting x-rays with an emission spectrum defined by the segment, among said plurality of segments, in which that emission center is located;
• a radiation detector that detects x-rays;
• a stand on which said x-ray source and said radiation detector are mounted allowing a subject to be placed therebetween so that said x-ray detector detects x-rays from said x-ray source that are attenuated by said subject;
• and
• a control unit that operates said x-ray source to acquire a tomosynthesis image data set.

An x-ray system comprising:

• an x-ray source comprising a housing, a plurality of electron sources in said housing, said electron sources being spaced apart from each other along a longitudinal direction, a single anode operable in common with all of said electron sources, said anode being mounted in said housing for rotation around a rotation axis that is parallel to and defines said longitudinal direction, said anode body being a composite comprising a base body and a cover layer over said base body, said cover layer being comprised of anode material that interacts with said electrons to emit x-rays, said base body and said cover layer being respectively comprised of different material compositions, said cover layer being subdivided into a plurality of segments each proceeding around a periphery of said anode body, said segments being spatially spaced apart from each other along said longitudinal direction each having respective emission spectrum, and each of said electron source emitting electrons that strike only a location in a respective one of said segments on said anode that are spatially separated from each other along said longitudinal direction, the respective locations forming separate emission centers, each emission center being individually associated with one of said electron sources, and each emission center emitting x-rays with an emission spectrum defined by the segment, among said plurality of segments, in which that emission center is located;
• a radiation detector that detects x-rays;
• a stand on which said x-ray source and said radiation detector are mounted allowing a subject to be placed therebetween so that said x-ray detector detects x-rays from said x-ray source that are attenuated by said subject;
• and
• a control unit that operates said x-ray source to selectively activate said plurality of electron sources to expose said subject to x-rays from respectively different exposure directions, each exposure direction being respectively associated with one of said emission centers of said x-ray source.