A pair of straight or angularly oriented flat emitters formed of an electron emissive material are positioned on an emitter support structure and are electrically connected to one another regardless of the mounting structure on which the emitters are positioned. The electrical connections between the emitters are formed directly between the emitters using electrically conductive material members that are placed between and affixed to the emitters to provide the electrical pathway or connection therebetween the emitters after formation of the emitters. These electrical connection members form an electrical connection between the angled pair of emitters separately from an emitter support structure on the cathode, such that the electrical connection members and angled emitters including the connection members can separate the mechanical architecture of the cathode assembly from the electrical architecture, thereby creating a simplified construction for the cathode assembly and associated x-ray tubes.

A method includes performing by a processor: estimating a total cathode space current for a thermionic vacuum tube having at least one grid and a plate, such that at least one amplification factor associated with the at least one grid is determined by a polynomial based on a variable that represents at plurality of voltages associated with the at least one grid and the plate, the variable being heuristically determine. Transitions between positive and negative grid operation may experience a step change in estimated current value caused by the inclusion or elimination of grid current. A part of the grid current may be added back into the plate current during transition. This small contribution to plate current may gradually diminish as tube operation moves farther away from the transition boundary.

A method includes performing by a processor: estimating a total cathode space current for a thermionic vacuum tube having at least one grid and a plate, such that at least one amplification factor associated with the at least one grid is determined by a polynomial based on a variable that represents at plurality of voltages associated with the at least one grid and the plate, the variable being heuristically determine. Transitions between positive and negative grid operation may experience a step change in estimated current value caused by the inclusion or elimination of grid current. A part of the grid current may be added back into the plate current during transition. This small contribution to plate current may gradually diminish as tube operation moves farther away from the transition boundary.

The present invention provides an emitter made of a hafnium carbide (HfC) single crystal that stably emits electrons with high efficiency, a method for manufacturing the emitter, and an electron gun and an electronic device using the emitter. An emitter according to an embodiment of the present invention is an emitter including a nanowire, in which the nanowire is made of the hafnium carbide (HfC) single crystal, at least an end of the nanowire through which electrons are to be emitted is coated with hafnium oxycarbide (HfC.sub.1-xO.sub.x: 0<x?0.5), and a field electron emission pattern of the end obtained by a field emission microscope (FEM) is a single spot.

Electron emitters and methods of fabricating the electron emitters are disclosed. According to certain embodiments, an electron emitter includes a tip with a planar region having a diameter in a range of approximately (0.05-10) micrometers. The electron emitter tip is configured to release field emission electrons. The electron emitter further includes a work-function-lowering material coated on the tip.

The present disclosure can relate to a thermionic emission device. The thermionic emission device can include a substrate layer, an insulating layer deposited onto an uppermost surface of the substrate layer, and an electron emitting layer deposited onto an uppermost surface of the insulating layer. The electron emitting layer, the insulating layer, and the substrate layer each can include a first etching and a second etching oriented according to a photoresist pattern applied to an uppermost surface of the electron emitting layer. The first etching and the second etching can converge to form a cavity in the substrate layer beneath a beam suspended above the cavity. The beam can comprise an unetched region of the electron emitting layer and the insulating layer oriented between the first etching and the second etching.

The present disclosure can relate to a thermionic emission device. The thermionic emission device can include a substrate layer, an insulating layer deposited onto an uppermost surface of the substrate layer, and an electron emitting layer deposited onto an uppermost surface of the insulating layer. The electron emitting layer, the insulating layer, and the substrate layer each can include a first etching and a second etching oriented according to a photoresist pattern applied to an uppermost surface of the electron emitting layer. The first etching and the second etching can converge to form a cavity in the substrate layer beneath a beam suspended above the cavity. The beam can comprise an unetched region of the electron emitting layer and the insulating layer oriented between the first etching and the second etching.

Cathode based on the C12A7:e-electride material for thermionic emission of electrons and procedure for its use. The specific ways and conditions for using the material C12A7: e (electride) as an electrode and more specifically as a cathode and more specifically as a cathode electron emitter in all applications likely to use the property, as electron emitting cathodes for ionic thrusters and neutralizers in aerospace applications, cathodes and electrodes in general that interact with ions, whether in a gaseous state (plasma) or liquid (electrolysis, water treatment, Hydrogen generation) or combination of both liquid and gaseous (Hydrogen fuel cell) as well as active (polarized) catalysts for the synthesis and decomposition of certain compounds (specifically ammonia). Focusing on maximizing the use of the material properties as a cathode and on its operation stability under different conditions, through specific pulsed polarization techniques that adapt precisely to the nature of the material.

Cathode based on the C12A7:e-electride material for thermionic emission of electrons and procedure for its use. The specific ways and conditions for using the material C12A7: e (electride) as an electrode and more specifically as a cathode and more specifically as a cathode electron emitter in all applications likely to use the property, as electron emitting cathodes for ionic thrusters and neutralizers in aerospace applications, cathodes and electrodes in general that interact with ions, whether in a gaseous state (plasma) or liquid (electrolysis, water treatment, Hydrogen generation) or combination of both liquid and gaseous (Hydrogen fuel cell) as well as active (polarized) catalysts for the synthesis and decomposition of certain compounds (specifically ammonia). Focusing on maximizing the use of the material properties as a cathode and on its operation stability under different conditions, through specific pulsed polarization techniques that adapt precisely to the nature of the material.

Methods and systems for thermal ionization of a sample and formation of an ion beam are described. The systems incorporate a thermal ionization filament that is formed of a graphene-based material such as graphite, graphene, graphene oxide, reduced graphene oxide or combinations thereof. The filament material can be doped or chemically modified to control and tune the work function of the filament and improve ionization efficiency of a system incorporating the filament. The systems can be utilized in forming an ion beam for target bombardment or analysis via, e.g., mass spectrometry.