Abstract:
A field emission device providing electric-field induced electron emission includes an annular edge emitter for emission of electrons. Emitted electrons are collected, at least in part, by an anode centrally disposed with respect to the annular edge emitter.
Abstract:
A field-emission type switching device includes a substrate formed with a recess having a straight edge and serrated edge opposite to the straight edge. A gate electrode is formed at the bottom of the recess. An emitter electrode is provided over the substrate and formed with a serrated edge which is slightly off alignment with the serrate edge of the recess so as to provide an emitter overhanging portion overhanging the recess. Similarly, a collector electrode is provided over the substrate means and formed with a straight edge which is slightly off alignment with the straight edge of the recess so as to provide a collector overhanging portion overhanging the recess. The emitter and collector electrodes are disposed in one plate and the gate electrode is disposed in another plane below the one plane.
Abstract:
Disclosed is hererin a quantum phase interference transistor comprising: an emitter for emitting electron waves into a vacuum; a gate electrode for controlling the phase difference between a plurality of electron waves; and a collector for collecting the electron waves; characterized in that the gate electrode has the construction of a capacitor.
Abstract:
A field emission device employs an anode in the form of an air bridge spanning the tip of a field emission cathode. The anode is supported only at its opposite ends, leaving the area under the air bridge open. An array of cathode emitters employ a series of parallel, laterally spaced anode air bridges, with each air bridge scanning a line of cathodes. The lateral spacing between the air bridges facilitates both the removal of underlying photoresist during fabrication, and the establishment of a uniform vacuum if desired. The clearance between the anode and cathode is substantially less than previously obtainable, resulting in a significant reduction in both size and in the anode's operating voltage level. Fabrication of the air bridge anodes can be integrated with the remainder of an integrated circuit.
Abstract:
A plasma X-ray tube, which can be referred to as a one-chamber ionizing tube for pre-ionizing TE lasers, in particular excimer lasers, includes an extended, box-like housing with a U-shaped hollow cathode which is disposed in the interior of the housing and is also elongated. The open side of the hollow electrode faces an X-ray target which is in the form of a gas-tight foil. Between the X-ray target and the hollow cathode is a long wire-shaped igniting electrode. When a positive voltage or a voltage pulse is applied to the igniting electrode, an electrical field is formed around it. Electrons that are present are forced onto a long, spiral path and gas atoms are ionized under the influence of the electrical field and because of ambient radiation. Electron avalanches form and lead to initiation of a wire discharge. When the accelerator voltage, which is typically at most between 60 kV and 120 kV, is applied to the hollow cathode low-pressure plasma, ions are extracted and accelerated against the hollow cathode. When the ions impact, secondary electrons are emitted from the hollow cathode and are accelerated in the opposite direction, so that an electron beam forms and strikes the X-ray target to generate X-ray retarding radiation. The plasma X-ray tube is fundamentally suitable as an electron gun, with a suitable electron-beam permeable configuration of a foil that covers the window opening in the target retaining wall and serves as an electron window.
Abstract:
A novel electron beam apparatus and technique wherein a plurality of longitudinally extending heated filaments is employed, each similarly offset laterally of a central longitudinal axis, but with successive filaments alternately disposed on opposite sides of said axis and cooperating with a first low velocity accelerating stage comprising staggered grid slots and openings, and a high velocity second accelerating stage to provide long uniform longitudinal electron beams.
Abstract:
A RF electron gun, such as for use in a linear electron accelerator, having a cathode activating device which, in one embodiment, includes means for altering the phase of the accelerating electric field to accelerate emitted electrons in the reverse direction to cause them to strike the cathode, thereby activating the cathode. In another embodiment, laser light is directed onto the cathode for activation thereof and, in a further embodiment, the electric field is positioned and directed at the cathode to cause the activation thereof.
Abstract:
A charged particle beam generating apparatus of multi-stage acceleration type includes a charged particle beam source and a multi-stage acceleration tube having a plurality of acceleration electrodes arranged in cascade over a plurality of stages within the tube. A plurality of outer shield electrodes are disposed in concentrical relation on the radially outer side of the multi-stage acceleration tube over the plural stages to be applied with the same potentials as those of the associated acceleration electrodes respectively. Finally, a plurality of dividing resistors are disposed outside of the multi-stage acceleration tube or between the outer shield electrodes and the multi-stage acceleration tube so as to apply predetermined potentials to the acceleration electrodes, respectively.
Abstract:
An apparatus is disclosed for producing an electron stream comprising an elongated first electrode and an elongated, surrounding electrode defining an exit aperture and spaced from the first electrode by an interelectrode distance. An gas source introduces ionizable gas between the electrodes. The interelectrode distance is typically less than the mean free path for molecular collisions in the gas, to thereby physically impede the flow of the gas in the interelectrode area. A magnetic field is applied between and parallel to the electrodes and an electric field is applied between the electrodes, both combining to discharge the gas. An extractor screen is juxtaposed to the exit aperture to attract an electron stream from the discharge. In preferred embodiments, the source of gas is pulsed and the screen is substantially transparent to electrons but only semi-transparent to gas molecules, thereby impeding their passage through the exit aperture.