Various methods and systems are provided for a cathode of an X-ray imaging system. A method for fabricating the cathode comprises machining a plurality of focusing features on a focusing element and welding the focusing element to a base assembly.

Various methods and systems are provided for a cathode of an X-ray imaging system. A method for fabricating the cathode comprises machining a plurality of focusing features on a focusing element and welding the focusing element to a base assembly.

An ion source for forming a plasma has a cathode with a cavity and a cathode surface defining a cathode step. A filament is disposed within the cavity, and a cathode shield has a cathode shield surface at least partially encircling the cathode surface. A cathode gap is defined between the cathode surface and the cathode shield surface, where the cathode gap defines a tortured path for limiting travel of the plasma through the gap. The cathode surface can have a stepped cylindrical surface defined by a first cathode diameter and a second cathode diameter, where the first cathode diameter and second cathode diameter differ from one another to define the cathode step. The stepped cylindrical surface can be an exterior surface or an interior surface. The first and second cathode diameters can be concentric or axially offset.

An ion source for forming a plasma has a cathode with a cavity and a cathode surface defining a cathode step. A filament is disposed within the cavity, and a cathode shield has a cathode shield surface at least partially encircling the cathode surface. A cathode gap is defined between the cathode surface and the cathode shield surface, where the cathode gap defines a tortured path for limiting travel of the plasma through the gap. The cathode surface can have a stepped cylindrical surface defined by a first cathode diameter and a second cathode diameter, where the first cathode diameter and second cathode diameter differ from one another to define the cathode step. The stepped cylindrical surface can be an exterior surface or an interior surface. The first and second cathode diameters can be concentric or axially offset.

There is provided an electron beam emitting assembly (12) comprising a filament element (40; 60) and a cathode element (42; 62), wherein the filament element (40; 60) is in direct physical contact with the cathode element (42; 62). The filament element (40; 60) is heatable to a temperature around the electron emission temperature of the cathode element (42; 62). The filament element is resistively heatable or inductively heatable. Also provided is a method of generating an electron beam comprising positioning a filament element and a cathode element in direct physical contact, and heating the filament element to a temperature around the electron emission temperature of the cathode element so as to cause the cathode element to emit electrons.

A high-power microwave (HPM) vacuum tube source and method of precise coaxial alignment of the field emission (FE) cathode, cylindrical RF generating tube and magnet field includes positioning a low-power thermionic emission (TE) cathode inside the FE cathode in a “cathode-in-cathode” arrangement. With the HPM source under vacuum and the FE cathode deactivated, the TE cathode emits a surrogate electron beam through the generating tube. Measurement circuits measure the surrogate electron beam's position with respect to a longitudinal axis fore and aft of the generating tube. The measurements circuits may, for example, be a repositionable fluorescent target or electric field sensors embedded in the cylindrical RF generating tube. The coaxial alignment of the primary cathode, cylindrical RE generating tube and magnet is adjusted until the position of the surrogate electron beam satisfies a coaxial alignment tolerance.

A high-power microwave (HPM) vacuum tube source and method of precise coaxial alignment of the field emission (FE) cathode, cylindrical RF generating tube and magnet field includes positioning a low-power thermionic emission (TE) cathode inside the FE cathode in a “cathode-in-cathode” arrangement. With the HPM source under vacuum and the FE cathode deactivated, the TE cathode emits a surrogate electron beam through the generating tube. Measurement circuits measure the surrogate electron beam's position with respect to a longitudinal axis fore and aft of the generating tube. The measurements circuits may, for example, be a repositionable fluorescent target or electric field sensors embedded in the cylindrical RF generating tube. The coaxial alignment of the primary cathode, cylindrical RE generating tube and magnet is adjusted until the position of the surrogate electron beam satisfies a coaxial alignment tolerance.

A cathode assembly for emitting charged particles, used in for example an electron gun as source for generating an electron beam is provided. The cathode assembly has a cathode including an emitting member and a carrier. The emitting member is mounted in the carrier, and the carrier is electrically connected to a holder. The cathode is heated by irradiation from an external source, whereby the emitting member emits charged particles from an emitting surface at an emitting temperature. The connection between the carrier and the holder provides a thermal barrier for reducing the amount of thermal energy transferred from the cathode to the holder.

Embodiments of the present invention describe electrical potential energy to electrical kinetic energy converters, ozone generators, and light emitters. A system for energy conversion from electrical potential energy to electrical kinetic energy may include a discharge device and a power supply. The power supply can be coupled with the discharge device, and supplies energy to the discharge device to form an initial electric field. The discharge device may further include at least two electrodes that are either mesh electrodes or wire-array electrodes. Furthermore, a space between the at least two electrodes is filled with a gas medium and an electric field is created by the power supply in a normal direction relative to planes formed by the elements of electrodes.

Embodiments of the present invention describe electrical potential energy to electrical kinetic energy converters, ozone generators, and light emitters. A system for energy conversion from electrical potential energy to electrical kinetic energy may include a discharge device and a power supply. The power supply can be coupled with the discharge device, and supplies energy to the discharge device to form an initial electric field. The discharge device may further include at least two electrodes that are either mesh electrodes or wire-array electrodes. Furthermore, a space between the at least two electrodes is filled with a gas medium and an electric field is created by the power supply in a normal direction relative to planes formed by the elements of electrodes.