Electron sources can include an electron source crystal coupled in series between opposing electrically conductive supports to form an electrically conductive path, wherein the electrical resistance of each of the electrically conductive supports is lower than the electrical resistance of the electron source crystal. Electron source crystals can include an emitting end and opposing shank end, wherein the shank end includes opposing leg portions. Electrically conductive supports can include foil supports spaced apart across a gap, wherein each of the opposing leg portions is attached to a respective foil support such that the foil supports are electrically connected to form the electrically conductive path. Particle focusing system are also disclosed. Electron sources can include an electron source crystal having an emitting end and opposing shank end, wherein the shank end is formed of a pair of opposing leg portions. Methods of manufacturing and operating electron sources are also disclosed.

The invention provides an electron beam apparatus that reduces a time required for an electron gun chamber to which a sputter ion pump and a non-evaporable getter pump are connected to reach an extreme high vacuum state. The electron beam apparatus includes an electron gun configured to emit an electron beam and the electron gun chamber to which the sputter ion pump and the non-evaporable getter pump are connected. The electron beam apparatus further includes a gas supply unit configured to supply at least one of hydrogen, oxygen, carbon monoxide, and carbon dioxide to the electron gun chamber.

The invention provides an electron beam apparatus that reduces a time required for an electron gun chamber to which a sputter ion pump and a non-evaporable getter pump are connected to reach an extreme high vacuum state. The electron beam apparatus includes an electron gun configured to emit an electron beam and the electron gun chamber to which the sputter ion pump and the non-evaporable getter pump are connected. The electron beam apparatus further includes a gas supply unit configured to supply at least one of hydrogen, oxygen, carbon monoxide, and carbon dioxide to the electron gun chamber.

Presented systems and methods facilitate efficient and effective monitoring of particle beams. In some embodiments, a radiation gun system comprises: a particle beam gun that generates a particle beam, and a gun control component that controls the gun particle beam generation characteristics, including particle beam fidelity characteristics. The particle beam characteristics can be compatible with FLASH radiation therapy. Resolution control of the particle beam generation can enable dose delivery at an intra-pulse level and micro-bunch level. The micro-bunch can include individual bunches per each 3 GHz RF cycle within the 5 to 15 μsec pulse-width. The FLASH radiation therapy dose delivery can have a bunch level resolution of approximately 4.4×10{circumflex over ( )}−6cGy/bunch.

Presented systems and methods facilitate efficient and effective monitoring of particle beams. In some embodiments, a radiation gun system comprises: a particle beam gun that generates a particle beam, and a gun control component that controls the gun particle beam generation characteristics, including particle beam fidelity characteristics. The particle beam characteristics can be compatible with FLASH radiation therapy. Resolution control of the particle beam generation can enable dose delivery at an intra-pulse level and micro-bunch level. The micro-bunch can include individual bunches per each 3 GHz RF cycle within the 5 to 15 μsec pulse-width. The FLASH radiation therapy dose delivery can have a bunch level resolution of approximately 4.4×10{circumflex over ( )}−6cGy/bunch.

A cathode mechanism of an electron emission source includes a crystal that includes an upper part being columnar, truncated conical, or their combined shape, and having a first surface to emit thermoelectrons, and a lower part, integrated with the upper part, having a second surface substantially parallel to the first surface, and a diameter larger than the maximum diameter of the upper part, a holding part that is a column having, in order from the holding part upper side, different inner diameters of a first diameter and a second diameter larger than the first one, and that holds the crystal in the state where the crystal first surface is projecting from the upper surface, and the crystal second surface contacts the holding part inside the column, and a retaining part that retains the crystal, at the back of the crystal lower part, not to be separated from the holding part.

A cathode mechanism of an electron emission source includes a crystal that includes an upper part being columnar, truncated conical, or their combined shape, and having a first surface to emit thermoelectrons, and a lower part, integrated with the upper part, having a second surface substantially parallel to the first surface, and a diameter larger than the maximum diameter of the upper part, a holding part that is a column having, in order from the holding part upper side, different inner diameters of a first diameter and a second diameter larger than the first one, and that holds the crystal in the state where the crystal first surface is projecting from the upper surface, and the crystal second surface contacts the holding part inside the column, and a retaining part that retains the crystal, at the back of the crystal lower part, not to be separated from the holding part.

The present disclosure provides a magnetic immersion electron gun and a method of generating an electron beam using a magnetic immersion electron gun. The electron gun includes a magnetic lens forming a magnetic field, a cathode tip disposed in the magnetic field, and a multi-filament heater configured to directly heat the cathode tip to emit electrons through the magnetic lens. The multi-filament heater includes a first filament connected at each end to first and second positive terminals of a power source and a second filament connected at each end to first and second negative terminals of the power source. The first positive terminal, the second positive terminal, the first negative terminal, and the second negative terminal are arranged alternately around the cathode tip such that the first filament and the second filament intersect at the cathode tip and a resultant magnetic force applied to the cathode tip is reduced.

The present disclosure provides a magnetic immersion electron gun and a method of generating an electron beam using a magnetic immersion electron gun. The electron gun includes a magnetic lens forming a magnetic field, a cathode tip disposed in the magnetic field, and a multi-filament heater configured to directly heat the cathode tip to emit electrons through the magnetic lens. The multi-filament heater includes a first filament connected at each end to first and second positive terminals of a power source and a second filament connected at each end to first and second negative terminals of the power source. The first positive terminal, the second positive terminal, the first negative terminal, and the second negative terminal are arranged alternately around the cathode tip such that the first filament and the second filament intersect at the cathode tip and a resultant magnetic force applied to the cathode tip is reduced.

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.