Traveling-wave tube amplifiers and methods for making slow-wave structures for the amplifiers are provided. The SWSs include helical conductors that are self-assembled via the release of stressed electrically conductive strips from a sacrificial material. The helical conductors can be electroplated post-self-assembly to fortify the helix, reduce losses, and tailor the dimensions and operating parameters of the helix.

Traveling-wave tube amplifiers and methods for making slow-wave structures for the amplifiers are provided. The SWSs include helical conductors that are self-assembled via the release of stressed electrically conductive strips from a sacrificial material. The helical conductors can be electroplated post-self-assembly to fortify the helix, reduce losses, and tailor the dimensions and operating parameters of the helix.

A charged particle buncher includes a series of spaced apart electrodes arranged to generate a shaped electric field. The series includes a first electrode, a last electrode and one or more intermediate electrodes. The charged particle buncher includes a waveform device attached to the electrodes and configured to apply a periodic potential waveform to each electrode independently in a manner so as to form a quasi-electrostatic time varying potential gradient between adjacent electrodes and to cause spatial distribution of charged particles that form a plurality of nodes and antinodes. The nodes have a charged particle density and the antinodes have substantially no charged particle density, and the nodes and the antinodes are formed from a charged particle beam with an energy less than or equal to 500 keV.

Traveling-wave tube amplifiers and methods for making slow-wave structures for the amplifiers are provided. The SWSs include helical conductors that are self-assembled via the release of stressed electrically conductive strips from a sacrificial material. The helical conductors can be electroplated post-self-assembly to fortify the helix, reduce losses, and tailor the dimensions and operating parameters of the helix.

Traveling-wave tube amplifiers and methods for making slow-wave structures for the amplifiers are provided. The SWSs include helical conductors that are self-assembled via the release of stressed electrically conductive strips from a sacrificial material. The helical conductors can be electroplated post-self-assembly to fortify the helix, reduce losses, and tailor the dimensions and operating parameters of the helix.

An electron gun includes: a cathode, which has a cathode holder and a cathode body; and a Wehnelt cylinder. The cathode holder receives the cathode body and the Wehnelt cylinder is suitable for bundling free electrons, which can escape from the cathode body toward the Wehnelt cylinder, to form an electron beam. The Wehnelt cylinder is interlockingly arranged, at least in some parts along a first inner surface facing the cathode holder, on an outer surface of the cathode holder and at least partly extends around the cathode holder.

A self-assembling element fabricated using integrated circuit techniques may provide a small diameter helical conductor surrounding an electron beam for the construction of a vacuum electronic device such as a traveling-wave tube for terahertz scale signal.

A slow-wave circuit comprises: a waveguide comprising a meander-shaped part that transmits an electromagnetic wave and alternately repeats a first folded part and a second folded part folded onto the opposite side to the first folded part; and a beam hole that transmits an electron beam, extends in a predetermined direction, and penetrates the meander-shaped part, wherein the beam hole penetrates the meander-shaped part so that a part of the beam hole protrudes from the first folded part.

A charged particle buncher includes a series of spaced apart electrodes arranged to generate a shaped electric field. The series includes a first electrode, a last electrode and one or more intermediate electrodes. The charged particle buncher includes a waveform device attached to the electrodes and configured to apply a periodic potential waveform to each electrode independently in a manner so as to form a quasi-electrostatic time varying potential gradient between adjacent electrodes and to cause spatial distribution of charged particles that form a plurality of nodes and antinodes. The nodes have a charged particle density and the antinodes have substantially no charged particle density, and the nodes and the antinodes are formed from a charged particle beam with an energy less than or equal to 500 keV.

A folded-waveguide slow-wave structure equipped with an internal load, includes a central plate comprising a rectilinear beam tunnel of same direction as the longitudinal axis of the central plate, and a serpentine-shaped folded slit having its folds in the direction of the width of the waveguide; a lower plate and an upper plate closing the waveguide, the plates being placed on and under the central plate, respectively; at least one groove of cross section that may be variable, produced along the longitudinal axis of the waveguide, in at least one face internal to the waveguide of the lower plate, the upper plate or the central plate, and at least partially comprising a lossy material; in order to form a closed slow-wave structure through which propagates a hybrid slow wave the amplitude of which is attenuated by at least 20 dB between the start and the end of the portion of the one or more grooves containing a lossy material.