US Patent 8000447 Co-axial, high energy gamma generator

A gamma ray generator includes an ion source in a first chamber. A second chamber is configured co-axially around the first chamber at a lower second pressure. Co-axially arranged plasma apertures separate the two chambers and provide for restricted passage of ions and gas from the first to the second chamber. The second chamber is formed by a puller electrode having at least one long channel aperture to draw ions from the first chamber when the puller electrode is subject to an appropriate applied potential. A plurality of electrodes rings in the third chamber in third pressure co-axially surround the puller electrode and have at least one channel corresponding to the at least one puller electrode aperture and plasma aperture. The electrode rings increase the energy of the ions to a selected energy in stages in passing between successive pairs of the electrodes by application of an accelerating voltage to the successive pairs of accelerator electrodes. A target disposed co-axially around the plurality of electrodes receives the beam of accelerated ions, producing gamma rays.