[Object] To provide an electron source that is lightweight, simple in configuration, and capable of suppressing characteristic degradation or recovering characteristics without causing an increase in power consumption. [Solving Means] A CNT electron source includes: a CNT emitter 32 for emitting electrons; a gate electrode 33 for extracting electrons from the CNT emitter 32; and a gate power supply connection switching relay 37a and a CNT emitter grounding switching relay 37b that cause the gate electrode 33 to emit electrons to irradiate the CNT emitter with electrons.

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.

An electron gun and an apparatus incorporating the electron gun. The electron gun includes an electron emission element, an electrode, a control element, and a control circuit. The electron emission element is arranged to be activated to emit electron beam. The electrode is arranged to be electrically connected with a power supply to accelerate the emitted electron beam. The control element may be arranged between the electron emission element and the electrode. The control element is arranged to be electrically connected with the power supply to provide an electric field to control emission of electron beams from the electron emission element. The control circuit is electrically connected with the control element for changing the electric field provided by the control element.

Radial radio frequency (RF) electron guns and radial RF electron gun systems are provided that are capable of generating an electron beam that can propagate either radially inward, towards the axis of a cylinder, or radially outward from the axis. A beam source capable of generating a radially inwardly propagating electron beam, while perhaps not particularly useful as a source for a higher-energy accelerator, offers potential advantages for materials processing, as the geometry allows irradiation from all sides of an enclosed material flow with a single structure. Other potential applications include, but are not limited to, atmospheric plasma generation, radiation damage testing, and possibly, novel electron lens-type devices for hadron accelerators.

The present disclosure provides a thruster device. The device includes a force-generating element mounted to a housing. The element is configured to generate a thrust force for propelling the housing. The element including a first electrode connected to a first input terminal of a power source. A second electrode is spaced apart by a predetermined distance from the first electrode and connected to a second input terminal of the power source. The second electrode includes a second longitudinal axis oriented parallelly to a first longitudinal axis. A dielectric medium is disposed between the electrodes. Upon receiving field emission condition, charged particles available at the first electrode accelerate towards the second electrode for generating a thrust force along a direction of movement of the charged particles. The thrust force is generated when the predetermined distance between the electrodes is shorter than a Rindler horizon defined by the charged particles during acceleration.

A beam injector may include a cathode emitter to emit electrons and an electrode to bias at least a portion of the electrons to remain on the cathode emitter and focus the emitted electrons into an electron beam. The beam injector may also include a resistor coupled between the cathode emitter and the electrode and configured to allow self-regulation of a voltage potential on the electrode based at least in part on a current of the electron beam.

An image intensifier sensor for acquiring, amplifying and displaying images and including a vacuum envelope, the image intensifier sensor including a photocathode arranged for releasing photoelectrons into the vacuum envelope upon electromagnetic radiation acquired from the images which impinges the photocathode, an anode, spaced apart from and in facing relationship with the photocathode, arranged for receiving the photoelectrons and converting the photoelectrons for displaying the images on the basis thereof, and a power supply unit for providing power to the image intensifier sensor, wherein the image intensifier sensor further includes potting material, wherein the potting material comprises a foam compound.

A beam injector may include a cathode emitter to emit electrons and an electrode to bias at least a portion of the electrons to remain on the cathode emitter and focus the emitted electrons into an electron beam. The beam injector may also include a resistor coupled between the cathode emitter and the electrode and configured to allow self-regulation of a voltage potential on the electrode based at least in part on a current of the electron beam.

This disclosure provides systems, methods, and apparatus related to electron emission. A method includes providing a nanotip field emitter. The nanotip field emitter includes a nanoprotrusion at a tip of the nanotip field emitter. The nanotip field emitter is cooled to a temperature. The temperature is about 80 Kelvin or lower. An electric field is applied between an extraction electrode and the nanotip field emitter to induce emission of electrons from the nanotip field emitter.

A tunable photocathode for use in vacuum electronic devices includes a nanostructured photoemission layer including quantum confined nanostructures, such as quantum dots. The quantum confined nanostructures can be tuned (e.g., prepared to have various characteristics or parameters) in order to independently optimize various characteristics of the electron beam emitted by the photocathode. For example, by changing the material composition, size and geometry of the quantum confined nanostructures, the energy levels of the quantum confined nanostructures in the photoemission layer can be tuned to provide a photocathode having a high quantum efficiency, low emittance, fast response time to incident light pulses, long operational lifetime, and increased environmental stability compared with conventional photocathodes and cathodes in vacuum electronic devices.