An x-ray source has multiple electron sources spaced apart from each other along a longitudinal direction that is defined as being parallel to the rotation axis of a rotating anode which is common to all of the electron sources. Each electron source emits electrons that strike the anode at respective strike points that are spatially separated from each other along the longitudinal direction, to produce respective emission centers, from which x-rays are emitted, each emission center being associated with respective ones of the x-ray sources.