An inspection system for scanning cargo and vehicles is described which employs an X-ray source that includes an electron beam generator, for generating an electron beam; an accelerator for accelerating said electron beam in a first direction; and, a first set of magnetic elements for transporting said electron beam into a magnetic field created by a second set of magnetic elements, wherein the magnetic field created by said second set of magnetic elements causes said electron beam to strike a target such that the target substantially only generates X-rays focused toward a high density section in the scanned object, which is estimated in a second pulse using image data captured by a detector array in a first pulse. The electron beam direction is optimized by said X-ray source during said second pulse to focus X-rays towards said high density section based on said image data in said first pulse.