1. An X-ray apparatus as part of a particle beam cancer therapy system, said particle beam cancer therapy system irradiating a tumor of a patient with a charged particle beam during use, said apparatus comprising: an electron generating cathode; a control electrode; a plurality of accelerating electrodes; a magnetic lens; and a quadrupole magnet, all of said control electrode, said accelerating electrodes, said magnetic lens, and said quadrupole magnet located between said cathode and an X-ray generating anode, said control electrode, said accelerating electrodes, said magnetic lens, and said quadrupole magnet combining to form a substantially parallel electron beam with an electron beam cross-sectional area, wherein a cross-sectional area of said cathode is greater than about six times that of the electron beam cross-sectional area, wherein said anode comprises a location within about forty millimeters of the charged particle beam.