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 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.

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.

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.

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

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

Emitter (3) and target (7) are arranged so as to face each other in vacuum chamber (1), and guard electrode (5) is provided at outer circumferential side of electron generating portion (31) of emitter (3). Guard electrode (5) is supported movably in directions of both ends of vacuum chamber (1) by guard electrode supporting unit (6). To perform regeneration process of guard electrode (5), guard electrode (5) is moved to opening (22) side (to separate position) by operating guard electrode supporting unit (6), and a state in which field emission of electron generating portion (31) is suppressed is set, then by applying voltage across guard electrode (5), discharge is repeated. After performing regeneration process, by operating guard electrode supporting unit (6) again, guard electrode (5) is moved to opening (21) side (to emitter position), and a state in which field emission of electron generating portion (31) is possible is set.

An electron beam apparatus which can stably achieve high spatial resolution also during low acceleration observation using CeB.sub.6 for the CFE electron source is provided. In an electron beam apparatus having a CFE electron source, the emitter of the electron beam of the CFE electron source is Ce hexaboride or a hexaboride of a lanthanoid metal heavier than Ce, the hexaboride emits the electron beam from the {310} plane, and the number of the atoms of the lanthanoid metal on the {310} plane is larger than the number of boron molecules comprising six boron atoms on the {310} plane.