Abstract: In an electron gun for use in a TWT, klystron, linear accelerator or other electron device, an electron gun header assembly and an input body assembly are coupled using a flexible bellows that allows the distance between the cathode and anode to be varied. As such, the perveance of the electron gun can be tuned, and the cathode magnetic field optimized for efficient operation. In addition, an external magnetic shield is adapted to be translated along the axial dimension of the electron gun to further optimize the cathode magnetic field and focusing characteristics to achieve improved electron gun performance.

Abstract: The invention provides an apparatus and method of switching more than one bias voltage within an electron beam tube in order to achieve electron beam cutoff. The invention is particularly useful for high-perveance electron tubes in which a large change in focus-electrode-to-cathode or anode-cathode voltage might otherwise be needed to achieve cutoff. In one embodiment of the invention, the cathode and anode bias voltages are both switched by magnitudes well within the capabilities of standard high-voltage switches to achieve beam cutoff.

Abstract: In an electron gun for use in a TWT, klystron, linear accelerator or other electron device, an electron gun header assembly and an input body assembly are coupled using a flexible bellows that allows the distance between the cathode and anode to be varied. As such, the perveance of the electron gun can be tuned, and the cathode magnetic field optimized for efficient operation. In addition, an external magnetic shield is adapted to be translated along the axial dimension of the electron gun to further optimize the cathode magnetic field and focusing characteristics to achieve improved electron gun performance.

Abstract: The invention provides an apparatus and method of switching more than one bias voltage within an electron beam tube in order to achieve electron beam cutoff. The invention is particularly useful for high-perveance electron tubes in which a large change in focus-electrode-to-cathode or anode-cathode voltage might otherwise be needed to achieve cutoff. In one embodiment of the invention, the cathode and anode bias voltages are both switched by magnitudes well within the capabilities of standard high-voltage switches to achieve beam cutoff.

Abstract: An electron gun comprises a shell having distal and proximal ends, a cathode structure disposed within the shell and having an electron emitting surface, an anode physically coupled to the shell at the distal end and spaced a fixed distance from the emitting surface, and a plurality of leads adapted to apply a voltage to the cathode structure with respect to the anode sufficient to cause emission of the electrons from the emitting surface. The anode has an aperture for passage therethrough of the beam of electrons emitted by the emitting surface. A first insulator is disposed within the shell proximal to the cathode structure. The first insulator has plural apertures having respective sizes in relation to corresponding ones of the plurality of leads such that the plurality of leads pass therethrough without contacting the first insulator. The first insulator provides stand-off for the voltage between the anode and cathode. A second insulator is disposed with the shell proximal from the first insulator.

Abstract: A collector for a linear beam has a segmented ceramic collector core that permits sustained operation at high temperatures and power densities. The collector provides efficient heat transfer from the while reducing stresses on collector components caused by thermal cycling and comprises a heat sink having a cavity providing interior vacuum walls for the collector a segmented ceramic insulator disposed inside the cavity, and an electrode disposed inside and against the insulator. The insulator comprises sectors separated from one another by gaps, and may be notched in its outer surface for high-voltage stand-off from the sink. The electrode is preferably not brazed/soldered to the insulator. A stage of the electrode may be probeless and comprise a depression. A molybdenum-fabricated heat sink and stage assembly utilizes an insulator constructed from beryllium oxide, aluminum nitride, or alumina; alternatively, a copper assembly, uses an aluminum nitride insulator.

Abstract: A collector structure for a linear bean device is disclosed having a segmented ceramic collector core that permits sustained operation at high temperatures and high power densities, such as encountered in miniature traveling wave tubes. More particularly, the collector assembly provides efficient heat transfer from the collector core at elevated temperatures while reducing stresses on collector components caused by thermal cycling. The collector assembly comprises a heat sink having a cylindrical cavity providing interior vacuum walls for the assembly, a segmented annular ceramic insulator disposed inside the cylindrical cavity, and an electrode disposed inside and against the ceramic insulator. The ceramic insulator comprises separate sectors separated from one another by gaps, and may be notched in its outer surface for high-voltage stand-off from the heat sink. The electrode is preferably not brazed or soldered to the ceramic insulator.

Abstract: A high power switching apparatus comprises an annular cathode having a surface capable of emitting a hollow electron beam therefrom and an anode cavity spaced from said cathode. The cavity has an annular opening smaller in dimension than a corresponding internal dimension that defines the cavity to provide a Faraday cage collector of the hollow electron beam. A control electrode, disposed between the cathode and the anode cavity in a non-intercepting position relative to the hollow electron beam, provides a controlling electric field region for modulation of the hollow electron beam. Arc suppressing electrodes, at approximately the same potential as the cathode, are disposed between the control electrode and the anode. An intermediate high voltage electrode, disposed between the arc suppressing electrodes and the anode cavity in a non-intercepting position relative to the hollow electron beam, provides a controlling electric field region for channeling of the hollow electron beam.

Abstract: A high power switching apparatus comprises an annular cathode having a surface capable of emitting a hollow electron beam therefrom and an anode cavity spaced from said cathode. The cavity has an annular opening smaller in dimension than a corresponding internal dimension that defines the cavity to provide a Faraday cage collector of the hollow electron beam. A control electrode is disposed between the cathode and the anode cavity in a non-intercepting position relative to the hollow electron beam. The control electrode further comprises a first electrode element disposed outside of the hollow electron beam and a second electrode element disposed inside of the hollow electron beam. A controlling electric field region is provided between the first and second electrode elements for modulation of the hollow electron beam. Arc suppressing electrodes are also disposed between the control electrode and the anode. The arc suppressing electrodes are the same electric potential of the cathode.

Abstract: A dual mode electronic countermeasures subsystem includes: a turnstile junction having two pairs of waveguide inputs and a cylindrical waveguide output; quadrature couplers; continuous wave microwave energy source means for applying CW microwave energy; and pulse microwave energy source means for applying pulses of microwave energy. Power from the source is premixed by quadrature couplers and then applied to the ports of the turnstile junction wherein the output of said turnstile junction comprises either or both continuous wave microwave energy or pulse microwave energy having polarization ellipticity determined by the degree of coupling. Suitably the microwave energy source means may include traveling wave type amplifier tubes and the cylindrical waveguide output of the turnstile junction may be connected directly to a suitable radiating system.