The disclosure includes an outer electrode and an inner electrode. The outer electrode defines an inner volume and is configured to receive injected electrons through at least one aperture. The inner electrode positioned in the inner volume. The outer electrode and inner electrode are configured to confine the received electrons in orbits around the inner electrode in response to an electric potential between the outer electrode and the inner electrode. The apparatus does not include a component configured to generate an electron-confining magnetic field.

The disclosure includes an outer electrode and an inner electrode. The outer electrode defines an inner volume and is configured to receive injected electrons through at least one aperture. The inner electrode positioned in the inner volume. The outer electrode and inner electrode are configured to confine the received electrons in orbits around the inner electrode in response to an electric potential between the outer electrode and the inner electrode. The apparatus does not include a component configured to generate an electron-confining magnetic field.

A hollow cathode apparatus includes an outer tubular dielectric barrier circumferentially surrounding an outer tubular surface of the cathode tube, the outer tubular dielectric barrier being composed of a barrier material which is electrically non-conductive. Also disclosed is a system comprising the hollow cathode apparatus, an anode which is spaced from the output end of the tubular cathode, and electrical circuitry connected between the cathode tube and the anode for connection to a source of electrical power for providing an electrical potential between the cathode and anode to cause an electric current to pass from the emitter into the input gas to form a plasma which is then output through the output end of the cathode tube to form a plasma plume. The electrical circuitry comprises: a first power supply for connecting the cathode and the cathode electrode to a first source of DC power in an ignition power mode, wherein the first power supply comprises a current control device which is adapted to control the current between the cathode and the cathode electrode, wherein the current control device is arranged to function as an anti-surge current stabiliser; and a second power supply for connecting the anode and the cathode to a second source of DC power in a steady state power mode.

A hollow cathode apparatus includes an outer tubular dielectric barrier circumferentially surrounding an outer tubular surface of the cathode tube, the outer tubular dielectric barrier being composed of a barrier material which is electrically non-conductive. Also disclosed is a system comprising the hollow cathode apparatus, an anode which is spaced from the output end of the tubular cathode, and electrical circuitry connected between the cathode tube and the anode for connection to a source of electrical power for providing an electrical potential between the cathode and anode to cause an electric current to pass from the emitter into the input gas to form a plasma which is then output through the output end of the cathode tube to form a plasma plume. The electrical circuitry comprises: a first power supply for connecting the cathode and the cathode electrode to a first source of DC power in an ignition power mode, wherein the first power supply comprises a current control device which is adapted to control the current between the cathode and the cathode electrode, wherein the current control device is arranged to function as an anti-surge current stabiliser; and a second power supply for connecting the anode and the cathode to a second source of DC power in a steady state power mode.

Disclosed is an electron beam emission device comprising a housing which defines a space in which electron beams are accelerated, and has an opening at the other side thereof through which the electron beams are emitted; a cathode which is disposed at one side in the housing, and emits the electrons; an anode which is positioned in the housing so as to be spaced apart from the cathode toward the other side, and accelerates the electrons emitted from the cathode; and an insulation holder which insulates a portion between the cathode and the housing, and fixes the cathode, wherein the cathode has a surface which faces the anode and is formed concavely to have a gradient, and a rim of the surface of the cathode, which has the gradient, is formed to be rounded.

An electron emission element of the present invention includes a lower electrode, a surface electrode, and a silicone resin layer disposed between the lower electrode and the surface electrode, wherein the surface electrode includes a silver layer, and the silver layer is in contact with the silicone resin layer.

An electron emission element of the present invention includes a lower electrode, a surface electrode, and a silicone resin layer disposed between the lower electrode and the surface electrode, wherein the surface electrode includes a silver layer, and the silver layer is in contact with the silicone resin layer.

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.

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.

The current stability of a field emission electron source and a Schottky electron source where a {100} plane of a hexaboride single crystal is used as an electron emission surface is improved. The electron source includes a tip of a hexaboride single crystal with a <100> axis, in which a top facet of a {100} plane that is surrounded by side facets including at least four {n11} planes and at least four {n10} planes where n represents an integer of 1, 2, or 3 is formed at a front end of the tip of the hexaboride single crystal, and a total area of the side facets of the {n11} planes is more than a total area of the side facets of the {n10} planes.