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 electron gun includes a cathode that is heated to emit thermions; a cathode heating power supply that supplies a cathode heating current for heating the cathode; a grid that has a first aperture formed therein and that has a grid voltage applied thereto, the grid voltage having a potential lower than that of the cathode, wherein the grid converges the thermions passing through the first aperture by the grid voltage; an anode that has a second aperture formed therein and that has an anode voltage applied thereto, wherein the anode causes the thermions extracted from the cathode to pass through the second aperture as an electron beam by the anode voltage; an anode-voltage power supply that applies the anode voltage to the anode; and a controller that causes the anode voltage having a positive potential to be applied from the anode-voltage power supply to the anode.

An electron gun includes a cathode that is heated to emit thermions; a cathode heating power supply that supplies a cathode heating current for heating the cathode; a grid that has a first aperture formed therein and that has a grid voltage applied thereto, the grid voltage having a potential lower than that of the cathode, wherein the grid converges the thermions passing through the first aperture by the grid voltage; an anode that has a second aperture formed therein and that has an anode voltage applied thereto, wherein the anode causes the thermions extracted from the cathode to pass through the second aperture as an electron beam by the anode voltage; an anode-voltage power supply that applies the anode voltage to the anode; and a controller that causes the anode voltage having a positive potential to be applied from the anode-voltage power supply to the anode.

An electron gun EG in which mixing of secondary electrons is suppressed is provided. The electron gun EG has an electron source 1, an extraction electrode 2 for extracting an electron beam E1 from the electron source 1, and an acceleration electrode for accelerating the extracted electron beam E1. The extraction electrode 2 includes a diaphragm 4 for allowing a part of the electron beam E1 to pass through, a shield 5 positioned above the diaphragm 4 apart from the diaphragm 4, and a shield 6 positioned below the diaphragm 4 apart from the diaphragm 4. The diaphragm 4 has an opening OP4 having an opening diameter D4, the shield 5 has an opening OP5 having an opening diameter D5 which is greater than the opening diameter D4, and the shield 6 has an opening OP6 having an opening diameter D6 which is greater than the opening diameter D4.

An electron gun EG in which mixing of secondary electrons is suppressed is provided. The electron gun EG has an electron source 1, an extraction electrode 2 for extracting an electron beam E1 from the electron source 1, and an acceleration electrode for accelerating the extracted electron beam E1. The extraction electrode 2 includes a diaphragm 4 for allowing a part of the electron beam E1 to pass through, a shield 5 positioned above the diaphragm 4 apart from the diaphragm 4, and a shield 6 positioned below the diaphragm 4 apart from the diaphragm 4. The diaphragm 4 has an opening OP4 having an opening diameter D4, the shield 5 has an opening OP5 having an opening diameter D5 which is greater than the opening diameter D4, and the shield 6 has an opening OP6 having an opening diameter D6 which is greater than the opening diameter D4.

The disclosure provides a metal ion source emitting device comprising a ceramic chamber, a leading-out electrode chamber and three cathodes hermetically connected, a trigger electrode fixed on a ceramic insulating element, a cathode target material fixed on an indirect cooling channel, a limiting element fixed on a fixed element, the fixed element fixing the indirect cooling channel on a cathode cooling pipe, the cathode cooling pipe fixed on a cathode flange, a trigger binding post connected with the trigger electrode, a leading-out electrode and an accelerating electrode arranged right below a cathode in the leading-out electrode chamber, and leading-out slits formed on the accelerating electrode and the leading-out electrode. According to the emitting device, three cathodes can operate simultaneously with only one anode, increasing irradiation area of an ion source, and improving the operating efficiency and energy utilization rate, with a more compact emitting source and larger processing area.

The disclosure provides a metal ion source emitting device comprising a ceramic chamber, a leading-out electrode chamber and three cathodes hermetically connected, a trigger electrode fixed on a ceramic insulating element, a cathode target material fixed on an indirect cooling channel, a limiting element fixed on a fixed element, the fixed element fixing the indirect cooling channel on a cathode cooling pipe, the cathode cooling pipe fixed on a cathode flange, a trigger binding post connected with the trigger electrode, a leading-out electrode and an accelerating electrode arranged right below a cathode in the leading-out electrode chamber, and leading-out slits formed on the accelerating electrode and the leading-out electrode. According to the emitting device, three cathodes can operate simultaneously with only one anode, increasing irradiation area of an ion source, and improving the operating efficiency and energy utilization rate, with a more compact emitting source and larger processing area.

An object is to provide an electron beam applicator suitable for an electron gun having a photocathode and an electron beam emission method in the electron beam applicator. The object can be achieved by an electron beam applicator including: an electron gun section; a main body section; and a control unit. The electron gun section includes a light source, a photocathode that emits an electron beam in response to receiving excitation light emitted from the light source, and an anode. The main body section includes an objective lens that converges an electron beam emitted from the electron gun section. The control unit controls at least convergence power of the objective lens in accordance with a size of an electron beam emitted from the photocathode.

An object is to provide an electron beam applicator suitable for an electron gun having a photocathode and an electron beam emission method in the electron beam applicator. The object can be achieved by an electron beam applicator including: an electron gun section; a main body section; and a control unit. The electron gun section includes a light source, a photocathode that emits an electron beam in response to receiving excitation light emitted from the light source, and an anode. The main body section includes an objective lens that converges an electron beam emitted from the electron gun section. The control unit controls at least convergence power of the objective lens in accordance with a size of an electron beam emitted from the photocathode.

A light emitting sealed body includes a housing which stores a discharge gas in an internal space and is provided with a first window portion to which first light is incident and a second window portion from which second light is emitted. The housing includes at least one flow path which is partitioned from the internal space and extends toward at least one of the first window portion and the second window portion.