Described herein is a traveling wave tube (TWT), comprising an electron gun configured to generate an electron beam (E-beam); a signal injector configured to generate a radio frequency (RF) signal; a slow wave structure (SWS) having an aperture configured to combine the E-beam and the RF signal; an outer wall enclosing the SWS; and at least one electromagnetically-active material on one of (1) at least one projection on at least one of a periphery of the SWS and on a side of the outer wall facing the SWS and (2) the periphery of the SWS configured to receive at least one electromagnetic signal to control, on-the-fly, amplification of the RF signal by maximizing dampening of spurious modes while minimizing dampening of operating modes.

Vacuum electron devices (VEDs) having a plurality of two-dimensional layers of various materials are bonded together to form one or more VEDs simultaneously. The two-dimensional material layers are machined to include features needed for device operation so that when assembled and bonded into a three-dimensional structure, three-dimensional features are formed. The two-dimensional layers are bonded together into a sandwich-like structure. The manufacturing process enables incorporation of metallic, magnetic, ceramic materials, and other materials required for VED fabrication while maintaining required positional accuracy and multiple devices per batch capability.

Vacuum electron devices (VEDs) having a plurality of two-dimensional layers of various materials are bonded together to form one or more VEDs simultaneously. The two-dimensional material layers are machined to include features needed for device operation so that when assembled and bonded into a three-dimensional structure, three-dimensional features are formed. The two-dimensional layers are bonded together into a sandwich-like structure. The manufacturing process enables incorporation of metallic, magnetic, ceramic materials, and other materials required for VED fabrication while maintaining required positional accuracy and multiple devices per batch capability.

Disclosed are methods and devices suitable for producing an electron beam.

Disclosed are methods and devices suitable for producing an electron beam.

Electron gun. The electron gun includes a circular cathode. The circular cathode comprises a spherical surface. The electron gun further includes a focus electrode. The focus electrode has four quadrants. The focus electrode is disposed about the circular cathode. The focus electrode includes four primary focus angle points. At least two of the four, adjacent, primary focus angle points have different angle values. Each of the four primary focus angle points is in a different quadrant. Focus angles on the focus electrode between any two primary focus angle points vary from one primary focus angle point to another primary focus angle point.

Electron gun. The electron gun includes a circular cathode. The circular cathode comprises a spherical surface. The electron gun further includes a focus electrode. The focus electrode has four quadrants. The focus electrode is disposed about the circular cathode. The focus electrode includes four primary focus angle points. At least two of the four, adjacent, primary focus angle points have different angle values. Each of the four primary focus angle points is in a different quadrant. Focus angles on the focus electrode between any two primary focus angle points vary from one primary focus angle point to another primary focus angle point.

Vacuum electron devices (VEDs) having a plurality of two-dimensional layers of various materials are bonded together to form one or more VEDs simultaneously. The two-dimensional material layers are machined to include features needed for device operation so that when assembled and bonded into a three-dimensional structure, three-dimensional features are formed. The two-dimensional layers are bonded together into a sandwich-like structure. The manufacturing process enables incorporation of metallic, magnetic, ceramic materials, and other materials required for VED fabrication while maintaining required positional accuracy and multiple devices per batch capability.

Vacuum electron devices (VEDs) having a plurality of two-dimensional layers of various materials are bonded together to form one or more VEDs simultaneously. The two-dimensional material layers are machined to include features needed for device operation so that when assembled and bonded into a three-dimensional structure, three-dimensional features are formed. The two-dimensional layers are bonded together into a sandwich-like structure. The manufacturing process enables incorporation of metallic, magnetic, ceramic materials, and other materials required for VED fabrication while maintaining required positional accuracy and multiple devices per batch capability.

An apparatus for generating Smith-Purcell radiation having at least one spectral component at a wavelength includes a periodic structure including a dielectric material and an electron source, in electromagnetic communication with the periodic structure, to emit an electron beam propagating within about 5 from a surface of the periodic structure to induce emission of the Smith-Purcell radiation. The electron beam has an electron energy tunable between about 0.5 keV and about 40 keV so as to change a wavelength of the Smith-Purcell radiation.