Abstract: A free-standing zeolite membrane and a zeolite membrane supported on a support structure are disclosed. The free-standing zeolite membrane is fabricated by mixing zeolite particles and an optional inorganic binder, forming a green body, and sintering the green body at a sufficiently low temperature so as to prevent damage to the gas selectivity properties of the zeolite particles. The supported composite zeolite membrane is fabricated by mixing a sacrificial binder, an optional inorganic binder, boehmite sol and zeolite particles to form a slurry. The slurry is then coated onto a porous support structure, dried and sintered at a sufficiently low temperature so as to prevent damage to the gas selective properties of the zeolite particles. In both membranes, the zeolite particles span the entire thickness of the membrane to provide a high selectivity path for the flow of gas to pass therethrough.

Abstract: A free-standing zeolite membrane and a zeolite membrane supported on a support structure are disclosed. The free-standing zeolite membrane is fabricated by mixing zeolite particles and an optional inorganic binder, forming a green body, and sintering the green body at a sufficiently low temperature so as to prevent damage to the gas selectivity properties of the zeolite particles. The supported composite zeolite membrane is fabricated by mixing a sacrificial binder, an optional inorganic binder, boehmite sol and zeolite particles to form a slurry. The slurry is then coated onto a porous support structure, dried and sintered at a sufficiently low temperature so as to prevent damage to the gas selective properties of the zeolite particles. In both membranes, the zeolite particles span the entire thickness of the membrane to provide a high selectivity path for the flow of gas to pass therethrough.

Abstract: A target system for producing intense epithermal and sub-MeV neutron fluxes from proton beams by the Li-7(p,n)Be-9 nuclear reaction by use of a layer of solid metallic lithium as the target material, which, in concert with a novel conical substrate to provide support and cooling, is designed to accept proton-beam power densities in excess of 1 MW m?2. The lithium is of limited thickness so that protons exit the lithium layer after reaching the threshold of the (p,n) reaction and deposit their remaining kinetic energy in the cooled substrate. In addition, the target system is configured in a novel geometry intended to confer symmetry around the beam axis of the resulting neutron fields—a feature particularly relevant to utilization of the claimed invention in boron-neutron capture therapy (BNCT).

Abstract: A linac system having at least two linac structures configured to operate with a resonant coupler. The linac structures and the resonant coupler resonate at the same frequency, are in close proximity, and designed for a relative phase of 0° or 180°. The coupling between the resonant coupler and the linac structures is achieved by slots between the linac structures and the resonant coupler, which allow the magnetic fields of the linac structures to interact with the magnetic field of the resonant coupler. The relative size of the slots determines the relative amplitude of the fields in the linac structures. There are three modes of oscillation, a 0 mode, wherein the linac structures and the resonant coupler are excited in phase, a ?/2 mode, wherein the linac structures are excited out of phase and the resonant coupler is nominally unexcited, and the ? mode, wherein the linac structures and the resonator coupler are excited out of phase.

Abstract: An interdigital (Wideröe) linear accelerator employing drift tubes, and associated support stems that couple to both the longitudinal and support stem electromagnetic fields of the linac, creating rf quadrupole fields along the axis of the linac to provide transverse focusing for the particle beam. Each drift tube comprises two separate electrodes operating at different electrical potentials as determined by cavity rf fields. Each electrode supports two fingers, pointing towards the opposite end of the drift tube, forming a four-finger geometry that produces an rf quadrupole field distribution along its axis. The fundamental periodicity of the structure is equal to one half of the particle wavelength ??, where ? is the particle velocity in units of the velocity of light and ? is the free space wavelength of the rf. Particles are accelerated in the gaps between drift tubes. The particle beam is focused in regions inside the drift tubes.

Abstract: An interdigital (Wideröe) linear accelerator employing drift tubes, and associated support stems that couple to both the longitudinal and support stem electromagnetic fields of the linac, creating rf quadrupole fields along the axis of the linac to provide transverse focusing for the particle beam. Each drift tube comprises two separate electrodes operating at different electrical potentials as determined by cavity rf fields. Each electrode supports two fingers, pointing towards the opposite end of the drift tube, forming a four-finger geometry that produces an rf quadrupole field distribution along its axis. The fundamental periodicity of the structure is equal to one half of the particle wavelength &bgr;&lgr;, where &bgr; is the particle velocity in units of the velocity of light and &lgr; is the free space wavelength of the rf. Particles are accelerated in the gaps between drift tubes. The particle beam is focused in regions inside the drift tubes.

Abstract: A linear accelerator of the interdigital (Wideröe) type, employing two-part drift tubes and associated support stems that couple to the electromagnetic fields of the interdigital linac structure, creating rf quadrupole fields along the axis of the linac to provide transverse focusing for the particle beam. Each two-part drift tube comprises two separate electrodes that operate at different electrical potentials. Each electrode supports two fingers, pointing inwards towards the opposite end of the drift tube, forming a four-finger geometry that produces an rf quadrupole field distribution along its axis. The fundamental periodicity of the structure is equal to one half of the particle wavelength &bgr;&lgr;, where &bgr; is the particle velocity in units of the velocity of light and &lgr; is the free space wavelength of the RF. Particles are accelerated in the gaps between drift tubes. The particle beam is focused in the regions inside the drift tubes.

Abstract: A source wire is in the path of a neutral particle beam formed from positively and negatively charged particles (ions) and neutral particles (atoms). The source wire strips electrons from the negatively charged particles to neutralize these particles and strips electrons from the neutral particles to create positively charged particles. A magnetic field is perpendicular to the path of the particle movement. A detector wire downstream from the source wire detects the total particle flux. A magnetic field is perpendicular to the path of the particle movement. A variation, preferably cyclical, may be provided in at least one of (a) the characteristics of the magnetic field and (b) the positioning of the detector wire relative to the source wire in a direction perpendicular to the magnetic field and the particle movement.

Abstract: A drift tube linac incorporates rf-electric quadrupole focusing by employing drift tubes with only one drift-tube stem per particle wavelength and in which the lowest frequency RF cavity mode has a transverse magnetic field (TM.sub.010 -mode). Each drift tube comprises two separate electrodes that form a capacitor that couples to the axial electric field of the primary cavity mode. The electrodes operate at different electrical potentials, as determined by the RF fields in the cavity, and are supported by a single stem along the axis of a cylindrical cavity. Each electrode supports two fingers pointing towards the opposite end of the drift tube, forming a four fingered geometry that produces an RF quadrupole field distribution along its axis. The fundamental periodicity of the structure is equal to the particle wavelength (.beta..lambda.) where .beta. is the particle velocity in units of the velocity of light and .lambda. is the free space wavelength of the rf.

Abstract: A radio frequency quadrupole (RFQ), which is a combination of the standard 4-vane and 4-rod designs, with a window or windows cut through mid-portions of the normally solid vanes. The windows decrease the resonant frequency, minimize undesirable mode coupling in the RFQ and result in a smaller and more easily tuned accelerator.

Abstract: A new RFQ linac structure extends the useful range of beam velocity by a factor of 2 to 4 and beam energy by a factor of 4 to 16. Four-finger electrodes extend into each accelerating cell and provide quadrupole focusing of beam particles along a beam axis. The finger electrodes of adjacent cells also provide quadrupole acceleration of the beam particles along the beam axis. The finger of adjacent cells are oriented in accordance with a prescribed pattern. The pattern orientation of the fingers provides an additional degree of freedom that allows the periodcity of the focal structure to be independent of the periodicity of the accelerating structure. This makes it possible to double the rf frequency periodically to enhance the acceleration rate while holding the focusing strength constant.

Abstract: A close-coupled rf power system provides high peak rf power for a linear accelerator, or "linac", and other charged particle systems. The linac operates in a vacuum housing. Low level rf power is coupled inside of the vacuum housing by a conventional rf feedthrough connector. An input resonator cavity mounts on the side of the linac within the vacuum housing. The resonator cavity couples rf power to one or more amplifier assemblies, each including at least one planar triode mounted directly on the linac housing, proximate one end of the resonator cavity. The planar triode, in turn, generates a high power rf current at its respective anode. The high power rf current couples to the linac through a conductive loop operating at the anode potential. Anode cooling is provided by pumping a suitable fluid, such as de-ionized water, through the conductive loop. The high power rf current in the loop generates magnetic fields in the linac required for its operation.

Abstract: A beam emittance measuring apparatus suitable for use with small diameter beams of the type commonly found in accelerators and beam transport systems. The apparatus includes a U-shaped frame that supports four thin wires that traverse the particle beam to create and detect thin particle shadows in the particle distribution. Two of the wires are shadow wires and are supported on one side of the U-shaped frame. Two of the wires are detection wires and are supported on the other side of the U-shaped frame, downstream from the shadow wires. One shadow wire and its corresponding detection wire are positioned to detect emittance data at a given point in a first emittance plane. The other shadow wire and its corresponding detection wire are positioned to detect emittance data at a given point in a second emittance plane.

Abstract: A plane wave transformer linear accelerator structure for accelerating charged particles to velocities greater than one-half the speed of light. The accelerator includes a tank section having a generally cylindrical tank wall. End plates each containing a central aperture for accommodating the passage of a charged particle beam are positioned adjacent to the ends of the tank wall. Support rods extend between the end plates, partially defining at least one axially-extending outer cavity and at least one axially-extending inner cavity. A plurality of axially-spaced washers situated substantially on the central axis of the tank section are supported by the rods. The washers each have central apertures which together define a charged particle beam acceleration path through the tank section.

Abstract: A coupled-cavity linear accelerator for accelerating charged particles to velocities greater than about one-third the speed of light. The accelerator includes a first tank for accelerating charged particles at a first velocity to a second velocity and a second tank for accelerating the particles to a higher third velocity. A bridge coupler for focusing a beam formed by the charged particles joins the first and second tanks. Each tank is substantially symmetrical about an axis and includes a generally cylindrical tank outer wall having an inner surface and an outer surface. A series of axially spaced disks are positioned inside the tank and bear on the inside tank surface. Each disk has an outer diameter greater than the as-manufactured inside diameter of the tank wall so that each disk causes an annular indentation in the inner surface of the outer wall. At least one washer is supported by each of alternating disks.

Abstract: A linear accelerator system includes a plurality of post-coupled drift-tubes wherein each post coupler is bistably positionable to either of two positions which result in different field distributions. With binary control over a plurality of post couplers, a significant accumlative effect in the resulting field distribution is achieved yielding a variable-energy drift-tube linear accelerator.

Abstract: A free electron laser and free electron laser amplifier using beam transport devices for guiding an electron beam to a wiggler of a free electron laser and returning the electron beam to decelerating cavities disposed adjacent to the accelerating cavities of the free electron laser. Rf energy is generated from the energy depleted electron beam after it emerges from the wiggler by means of the decelerating cavities which are closely coupled to the accelerating cavities, or by means of a second bore within a single set of cavities. Rf energy generated from the decelerated electron beam is used to supplement energy provided by an external source, such as a klystron, to thereby enhance overall efficiency of the system.

Abstract: A catalac free electron laser using a rf linac (catalac) which acts as a catalyst to accelerate an electron beam in an initial pass through the catalac and decelerate the electron beam during a second pass through the catalac. During the second pass through the catalac, energy is extracted from the electron beam and transformed to energy of the accelerating fields of the catalac to increase efficiency of the device. Various embodiments disclose the use of post linacs to add electron beam energy extracted by the wiggler and the use of supplementary catalacs to extract energy at various energy peaks produced by the free electron laser wiggler to further enhance efficiency of the catalac free electron laser. The catalac free electron laser can be used in conjunction with a simple resonator, a ring resonator or as an amplifier in conjunction with a master oscillator laser.

Abstract: A free electron laser system and electron beam system for a free electron laser which use rf feedback to enhance efficiency. Rf energy is extracted from an electron beam by decelerating cavities and returned to accelerating cavities using rf returns such as rf waveguides, rf feedthroughs, etc. This rf energy is added to rf klystron energy to lower the required input energy and thereby enhance energy efficiency of the system.

Abstract: A heavy particle linear accelerator employing rf fields for transverse and ongitudinal focusing as well as acceleration. Drift tube length and gap positions in a standing wave drift tube loaded structure are arranged so that particles are subject to acceleration and succession of focusing and defocusing forces which contain the beam without additional magnetic or electric focusing fields.