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 comprising a cathode having an electron emitting surface and whose planar shape is circular, a heater to increase the temperature of the cathode, and an anode to apply a positive electric potential relative to the cathode to extract electrons in a predetermined direction is provided. The cathode comprises a through hole at a central portion thereof along a central axis of the cathode, and either the cathode comprises a no-emitting layer at at least one of an opening edge on the electron emitting surface side of the through hole and an inner surface of the through hole, or the opening edge on the electron emitting surface side of the through hole is a chamfered C surface or a chamfered R surface.

A device for generating a source current of charge carriers and a method for stabilizing a source current of charge carriers are disclosed. In an embodiment the device includes at least one field emission element configured to emit charge carriers, which lead to an emission current in the field emission element, at least one extraction electrode configured to apply an extraction voltage in order to extract the charge carriers from the field emission element, wherein a first part of the extracted charge carriers contributes to the source current, and a second part of the extracted charge carriers impinges on the extraction electrode and leads to an extraction current in the extraction electrode and a control device configured to reduce fluctuations of a controlled variable Q which is a characteristic for the source current, wherein Q is a function of a difference between the emission current and the extraction current.

A device for generating a source current of charge carriers and a method for stabilizing a source current of charge carriers are disclosed. In an embodiment the device includes at least one field emission element configured to emit charge carriers, which lead to an emission current in the field emission element, at least one extraction electrode configured to apply an extraction voltage in order to extract the charge carriers from the field emission element, wherein a first part of the extracted charge carriers contributes to the source current, and a second part of the extracted charge carriers impinges on the extraction electrode and leads to an extraction current in the extraction electrode and a control device configured to reduce fluctuations of a controlled variable Q which is a characteristic for the source current, wherein Q is a function of a difference between the emission current and the extraction current.

According to some aspects, a cold cathode device is provided, the device comprising a substrate, a field electron emitter disposed upon the substrate and configured to emit electrons in a first direction, and a structure encapsulating the field electron emitter, thereby creating an airtight seal around the field electron emitter, at least a portion of the structure being an atomically thin membrane positioned in the first direction with respect to the field electron emitter. According to some embodiments, at least one einzel lens may be located within the structure and configured to direct electrons emitted by the field electron emitter.

According to some aspects, a cold cathode device is provided, the device comprising a substrate, a field electron emitter disposed upon the substrate and configured to emit electrons in a first direction, and a structure encapsulating the field electron emitter, thereby creating an airtight seal around the field electron emitter, at least a portion of the structure being an atomically thin membrane positioned in the first direction with respect to the field electron emitter. According to some embodiments, at least one einzel lens may be located within the structure and configured to direct electrons emitted by the field electron emitter.

A device for generating a source current of charge carriers and a method for stabilizing a source current of charge carriers are disclosed. In an embodiment the device includes at least one field emission element configured to emit charge carriers, which lead to an emission current in the field emission element, at least one extraction electrode configured to apply an extraction voltage in order to extract the charge carriers from the field emission element, wherein a first part of the extracted charge carriers contributes to the source current, and a second part of the extracted charge carriers impinges on the extraction electrode and leads to an extraction current in the extraction electrode and a control device configured to reduce fluctuations of a controlled variable Q which is a characteristic for the source current, wherein Q is a function of a difference between the emission current and the extraction current.

A device for generating a source current of charge carriers and a method for stabilizing a source current of charge carriers are disclosed. In an embodiment the device includes at least one field emission element configured to emit charge carriers, which lead to an emission current in the field emission element, at least one extraction electrode configured to apply an extraction voltage in order to extract the charge carriers from the field emission element, wherein a first part of the extracted charge carriers contributes to the source current, and a second part of the extracted charge carriers impinges on the extraction electrode and leads to an extraction current in the extraction electrode and a control device configured to reduce fluctuations of a controlled variable Q which is a characteristic for the source current, wherein Q is a function of a difference between the emission current and the extraction current.

Some embodiments include a system, comprising: a high voltage enclosure; a cathode disposed in the high voltage enclosure; an anode disposed in the high voltage enclosure; a plurality of grids disposed in the high voltage enclosure between the cathode and the anode; a voltage source configured to generate a common grid voltage; and a voltage divider disposed in the high voltage enclosure, configured to generate a plurality of grid voltages based on the common grid voltage, and configured to apply at least two of the grid voltages to the grids.

Some embodiments include a system, comprising: a high voltage enclosure; a cathode disposed in the high voltage enclosure; an anode disposed in the high voltage enclosure; a plurality of grids disposed in the high voltage enclosure between the cathode and the anode; a voltage source configured to generate a common grid voltage; and a voltage divider disposed in the high voltage enclosure, configured to generate a plurality of grid voltages based on the common grid voltage, and configured to apply at least two of the grid voltages to the grids.