Abstract: A method and apparatus for preventing oscillations in high-current electron guns. Spurious oscillations frequently occur as a result of interaction of the electron stream with the fields of resonant modes of the gun structure. The resonant impedances of the modes are lowered by damping with lossy dielectric or resistive materials which are suited to the high temperature and vacuum environment of electron guns. The lossy materials are located in places shielded from high electric fields applied to the gun. Lossy dielectric materials which are D.C. insulators may be used as insulating supports for gun electrodes.

Abstract: A semiconductor is positioned as the anode of an electron tube, and is borded with a radio-frequency modulated stream of electrons. This bombardment produces carrier pairs in the semiconductor in a well known manner. However, in this case the carrier pairs are bunched, in the same manner as the modulating electrons, as they are drawn through the semiconductor by its bias voltage. A radio-frequency coil or meander line adjacent to the semiconductor interacts with the bunched carrier pairs traveling through the semiconductor -- in the same manner as the radiofrequency coil of a traveling wave tube interacts with the electrons of a traveling wave tube, as they become bunched -- to produce an amplified r-f signal in the coil.

Abstract: A periodic permanent magnet electron beam focusing arrangement integrated with a traveling-wave tube coupled cavity slow-wave structure is disclosed which achieves maximum peak power output in a compact design of minimum size, weight and cost. A plurality of annular permanent magnets and ferromagnetic pole pieces are alternately disposed coaxially about the electron beam path, with the pole pieces extending slightly radially inwardly of the magnets. A number n (where n is a positive integer not less than two) of annular platelike members and (n - 1) annular spacer members, each of electrically conductive non-magnetic material, are disposed radially within each magnet. The inner circumferential surfaces of the spacer members and of the pole pieces constitute lateral walls for different ones of the slow-wave structure interaction cavities, the broad surfaces of the plate-like members constituting end walls for the cavities.

Abstract: An interdigital delay line for crossed field tubes has vanes extending from their interaction faces to a back wall. One end of each vane extends to the end of the face. The other end is cut out behind the interaction face leaving the face projecting. The interaction impedance is almost as high as that of a line with fingers supported by stubs at their centers, while the thermal dissipation is higher, approaching that of a line with vanes extending over the entire length of the fingers.

Abstract: Diamond heat sink members are now employed to conduct thermal energy from slow wave structures in traveling wave type interaction devices to permit operation at high power levels. The diamond members are bonded to adjacent desired components by a method including heating an intermediate metal alloy of an inactive conductive metal and a small amount of a carbide constituent in a vacuum and the application of pressure. A critical temperature slightly above the melting point of the alloy of between 1000.degree. C and 1100.degree. C is required to wet and bond the alloy material to the diamond and any desired surface.

Abstract: In order to reduce the drawbacks, encountered in microwave electronic tubes, resulting from the presence of electrons reflected from the collector of these tubes towards the tube input, the invention provides for the collectors of these tubes to take the form of hollow bodies whose at least part of the internal volume exhibits an axis of symmetry not coinciding with the axis of the beam. This arrangement reduces the number of electrons liable to return towards the tube input and produces a spread in their phases. Application is made to klystrons.

Abstract: A traveling wave tube amplifier is disclosed. The amplifier employs a helix derived slow wave circuit arranged for electromagnetic interaction with a stream of electrons for amplifying wave energy applied to the slow wave circuit. A plurality of loading conductors are disposed about the outside surface of the slow wave circuit and extending lengthwise thereof. The conductors are arranged such that the spacing from the conductors to the slow wave circuit decreases toward its downstream end. The conductors are arranged such that they conduct radio frequency currents longitudinally of the slow wave circuit and do not appreciably conduct r.f. current in the direction circumferentially about the axis r.f. power flow on the slow wave circuit. Such loading conductors serve to decrease the phase velocity for wave energy on the circuit over the passband of the circuit. As a result, the interaction efficiency is substantially improved over the passband of the traveling wave tube amplifier.

Abstract: The collector wall axially coextensive with the expanding beam of electrons includes at least portions thereof which extend inwardly to closely approach the periphery of the beam of electrons at several axially spaced planes. In its simplest form this structure consists of a series of annular baffle plates each having a central aperture of a diameter only slightly larger than the diameter of the beam at the axial plane in the collector where the baffle plate is located. These baffle plates have been found to substantially reduce the number of secondary (impact-produced) electrons which return from the collector to the interaction sections of the linear beam microwave tube. As a result spurious signals and noise caused by back-streaming secondary electrons are significantly reduced.

Abstract: The body current of a TWT (traveling wave tube) is measured by generating a voltage that is proportional to the difference between the cathode and collector currents of the TWT without materially affecting either by passing the cathode and collector currents through separate transformer windings, wound in opposition, on both a linear core transformer and a nonlinear core transformer with separate windings coupling each transformer to the other. A voltage pulse is introduced into another winding on the nonlinear transformer causing a current flow in the circuit coupling the two transformers, the voltage magnitude of which is proportional to the difference between the cathode and collector currents which is the body current.

Abstract: A circuit is provided in a traveling-wave tube package which eliminates the need of manually setting the power supply voltage to match the proper operating voltage of the tube. The circuit utilized within the traveling-wave tube package forms a part of the power supply, the remainder of which is provided externally of the traveling-wave tube package. By selecting the proper circuit components, the traveling-wave tube package can be connected without adjustment to a power supply and still operates at the desired voltage.