Patent ID: 7064477

Claim:
A method for providing electrons for an electron beam instrument, the method comprising: providing an electron emitter for emitting electrons when heated; providing a heating filament in thermal contact with the electron emitter to heat the electron emitter when electrical current is passed through the heating filament, the electron emitter having extending from the filament and having a distal end converging to an emitter tip; providing two or more filament posts in electrical contact with the heating filament to provide electrical current to beat the filament; providing a base supporting the filament posts, the base having an outside length parallel to the filament posts and providing an outer surface area sufficient for firmly securing the base within the electron beam system and the base including a contact area between each filament post and the base, the contact area having a length parallel to the filament posts, the contact area length being significantly less than the outside length, thereby reducing the thermal contact area between the base and the filament post and reducing heat losses of the electron source; passing an electric current through the filament posts to the heating filament to heat the emitter, and providing an electric field at the tip of the electron emitter to cause the emitter to emit electrons.