Patent ID: 6064686
Filing Date: 2000-05-16
Classification: H01J

Abstract:
An electron gun, comprising:an emitter assembly including:a filament that when heated emits electrons,a cathode plate disposed adjacent to the filament and forming a cathode window aligned to the filament,an anode plate disposed adjacent to the cathode plate and forming an anode window aligned to the cathode window,wherein, the cathode plate and anode plate are connectable to a voltage source for forming an electrostatic field that directs the emitted electrons into an electron stream that traverses through the cathode window and the anode window;a magnet assembly including:a crucible,a magnet that generates a magnetic field for guiding the electron stream along a path to the crucible;wherein the anode window, cathode window and filament are aligned with each other to form an electrostatic lens that minimizes the divergence of the electron stream.