Abstract: Described is a self-contained, small, lightweight, power-efficient and radiation-shielded module that includes a miniature vacuum X-ray tube emitting X-rays of a controlled intensity and defined spectrum. Feedback control circuits are used to monitor and maintain the beam current and voltage. The X-ray tube, high-voltage power supply, and the resonant converter are encapsulated in a solid high-voltage insulating material. The module can be configured into complex geometries and can be powered by commercially available small, compact, low-voltage batteries.

Abstract: Described is a self-contained, small, lightweight, power-efficient and radiation-shielded module that includes a miniature vacuum X-ray tube emitting X-rays of a controlled intensity and defined spectrum. Feedback control circuits are used to monitor and maintain the beam current and voltage. The X-ray tube, high-voltage power supply, and the resonant converter are encapsulated in a solid high-voltage insulating material. The module can be configured into complex geometries and can be powered by commercially available small, compact, low-voltage batteries.

Abstract: A method and apparatus for ion beam generation in which acceleration of an ion beam in a first accelerating tube to a high voltage terminal, followed by transport of the beam through the terminal without significant charge changing, and deceleration of the beam substantially to ground potential in a second accelerating tube. Since the terminal is maintained at high voltage, the beam optical characteristics between the ion source and the terminal are identical to those of normal tandem operation. The optical elements of the injector and accelerator beamline can therefore be adjusted to produce an focused beam envelope in the high voltage terminal, allowing the beam to propagate efficiently through an empty stripper canal. Since the beam, does not undergo a charge change in the terminal, it is decelerated in the second tandem accelerating tube. Since the beam propagates through the accelerator at energies higher than the injection energy, expansion of the beam due to space charge and emittance is reduced.

Abstract: A miniature x-ray unit includes a first electrical node, a second electrical node and an insulating material. The first and second nodes are separated by a vacuum gap. The first node includes a base portion and a projecting portion, wherein the projecting portion and the second node are surrounded by an x-ray transmissive window through which x-rays exit the unit. The insulating material coaxially surrounds the base portion of the first node such that the insulating material is recessed from the vacuum gap, and the insulator does not extend into the vacuum gap. Recessing the insulating material from the vacuum gap decreases the likelihood that the insulator will electrically break down due to the accumulation of electrical charge, and/or the accumulation of other materials on the surface of the insulator. In a preferred embodiment, the first node is an anode and the second node is a cathode. Alternatively, the first node may be the cathode and the second node may be the anode.

Abstract: This invention relates to a method and apparatus for the generation of isotopes, and in particular radioisotopes, from a target material which is not normally a solid and which, when bombarded by selected high energy particles, produces the selected isotope. A surface is provided which is preferably of a thermally-conductive material, which surface is cooled to a temperature below the freezing temperature of the target material. A thin layer of target material is then frozen on the surface and the target material is bombarded with the high energy particles. The beam of high energy particles is preferably at an angle to the surface such that the particles pass through a thickness of the target material greater than the thickness of the layer before reaching the surface. When the desired quantity of isotope has been produced from the target material, the target material, which has now been altered nuclearly to contain the selected isotope, is removed from the surface.

Abstract: A method and apparatus are provided for performing non-invasive measurements, and in particular in vivo non-invasive measurements of the total body content of a particular element, or of the content of such elemetn in a particular body area, by use of resonant gamma ray detection. More particularly, gamma rays are generated at the resonant gamma absorption energy level for the element on which measurements are to be made and are passed through the portion of the patient's body for which measurements are to be made. Detected gamma rays passing through the patient's body may be utilized as an indication of the content of such element. The effect of non resonant gamma absorption may be subtracted by also passing gamma rays of non-resonant absorption energy through the same body part and utilizing detected gamma rays at this energy passing through the body to determine the non-resonant absorptions.

Abstract: Window constructions for use in particle accelerators to separate an evacuated accelerator beam chamber from a gas or liquid filled target area, which window structure enhances cooling of the foil covering the window opening and reduces stresses on the foil. For preferred embodiments, the window opening is shaped and dimensioned to provide high length-to-width aspect ratio and a rectangular shape with rounded corners. The openings should generally be as narrow as possible while still being wide enough to assure efficient transmission of the ion beam. Stresses in the foil is reduced by providing controlled bowing of the portions of the foil covering the window. This may be accomplished by providing some slack in the foil, at least in one dimension, but is preferably accomplished by pressing the foil between mating curved surfaces selectively extending from the edges of the window openings, resulting in the desired bow in the foil in the window area.

Abstract: A high energy, charged particle accelerator, and radiation sources utilizing such accelerator are provided. More particularly, a high yield neutron generator and apparatus for the use of such generator are provided. The generator utilizes an ion source, a target adapted to generate neutrons when bombarded by high energy ions and an accelerator tube between the source and target. A multistage cascade rectifier is paraxial with the accelerator tube and has a voltage gradient which substantially matches that of the accelerator tube. The cascade rectifier preferably surrounds the accelerator tube and has equipotential metal plates on each side of each stage, the potential gradients between each pair of plates being substantially uniform and being substantially equal to the voltage gradient in the adjacent section of the accelerator tube. Generator elements may be enclosed in a pressure vessel and a moderator may be provided in the vessel, near the target to thermalize neutrons emitted from the target.

Abstract: An energy substraction medical imaging system which is used for imaging a body part impregnated with a radio-opaque dye such as iodine is provided. The system includes an electron beam target having a target surface which, when excited by a high-energy electron beam, generates radiation having strong K.sub..alpha. at energy levels slightly above and slightly below the K-edge energy level of the dye. The target surface is preferably formed of a compound containing lanthanum, such as lanthanum oxide. The target may also be formed of a compound containing a material having a K.sub..alpha. line at an energy level slightly above the dye K-edge and a material with K.sub..alpha. line slightly below the dye K-edge or with separate sections containing such materials which are alternately excited. The target is excited by a high-energy electron beam from a suitable source, the electron beam having sufficient energy to provide a high photon yield at the K.sub..alpha.

Abstract: A high current (0.2 to at least 2 milliamperes), low-energy (2.2 to 4 MV) ion beam is generated and is utilized to produce clinically significant quantities of medical isotopes useful in applications such as positron emission tomography. For a preferred embodiment, a tandem accelerator is utilized. Negative ions generated by a high current negative-ion source are accelerated by an electrostatic accelerator in which the necessary high voltage is produced by a solid state power supply. The accelerated ions then enter a stripping cell which removes electrons from the ions, converting them into positive ions. The positive ions are then accelerated to a target which is preferably at ground potential.

Abstract: A high current (0.2 to at least 2 milliamperes), low-energy (2.2 to 4 MV) ion beam is generated and is utilized to produce clinically significant quantities of medical isotopes useful in applications such as positron emission tomography. For a preferred embodiment, a tandem accelerator is utilized. Negative ions generated by a high current negative-ion source are accelerated by an electrostatic accelerator in which the necessary high voltage is produced by a solid state power supply. The accelerated ions then enter a stripping cell which removes electrons from the ions, converting them into positive ions. The positive ions are then accelerated to a target which is preferably at ground potential.