Simplified particle emitter and method of operating thereof

摘要

An emitter assembly for emitting a charged particle beam along an optical axis is described. The emitter assembly being housed in a gun chamber and includes an emitter having an emitter tip, wherein the emitter tip is positioned at a first plane perpendicular to the optical axis and wherein the emitter is configured to be biased to a first potential, an extractor having an opening, wherein the opening is positioned at a second plane perpendicular to the optical axis and wherein the extractor is configured to be biased to a second potential, wherein the second plane has a first distance from the first plane of 2.25 mm and above.