Provided is a field emission device including a cathode electrode and an anode electrode, which are spaced apart from each other, an emitter disposed on the cathode electrode, a gate electrode disposed between the cathode electrode and the anode electrode and including a gate opening that overlaps the emitter, and a plurality of alignment electrodes disposed between the gate electrode and the cathode electrode. Here, the alignment electrodes surround a side surface of the emitter.

Vacuum electron devices (VEDs) are produced having a plurality of two-dimensional layers of various materials that 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 using brazing, diffusion bonding, assisted diffusion bonding, solid state bonding, cold welding, ultrasonic welding, and the like. The manufacturing process enables incorporation of metallic, magnetic, and ceramic materials required for VED fabrication while maintaining required positional accuracy and multiple devices per batch capability. The VEDs so produced include a combination of magnetic and electrostatic lenses for electron beam control.

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.

Provided is a field emission device including a cathode electrode and an anode electrode, which are spaced apart from each other, an emitter disposed on the cathode electrode, a gate electrode disposed between the cathode electrode and the anode electrode and including a gate opening that overlaps the emitter, and a plurality of alignment electrodes disposed between the gate electrode and the cathode electrode. Here, the alignment electrodes surround a side surface of the emitter.

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) are produced having a plurality of two-dimensional layers of various materials that 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 using brazing, diffusion bonding, assisted diffusion bonding, solid state bonding, cold welding, ultrasonic welding, and the like. The manufacturing process enables incorporation of metallic, magnetic, and ceramic materials required for VED fabrication while maintaining required positional accuracy and multiple devices per batch capability. The VEDs so produced include a combination of magnetic and electrostatic lenses for electron beam control.

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) are produced having a plurality of two-dimensional layers of various materials that 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 using brazing, diffusion bonding, assisted diffusion bonding, solid state bonding, cold welding, ultrasonic welding, and the like. The manufacturing process enables incorporation of metallic, magnetic, and ceramic materials required for VED fabrication while maintaining required positional accuracy and multiple devices per batch capability. The VEDs so produced include a combination of magnetic and electrostatic lenses for electron beam control.

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.

According to one embodiment, an X-ray tube includes an anode target, a cathode including a filament and a convergence electrode which includes a groove portion, and an envelope. The groove portion includes a pair of first bottom surfaces which are located in the same plane as the filament and between which the filament is interposed in a width direction of the groove portion, and a pair of second bottom surfaces between which the filament and the pair of first bottom surfaces are interposed in a length direction of the groove portion and which are located closer to an opening of the groove portion than the pair of first bottom surfaces.