Electron gun with laser beam heating, for scanning or transmission electron microscopy or e-beam holography

摘要

The electron gun involves a laser oscillator (6) whose output is directed by an optical system (7,8,9,16) into an electron gun chamber (18) where it is focussed onto the tip of a filament that emits the electrons. The photoelectric effect of the laser produces a thermal heating effect which results in electron emission. A pyrometer is focussed through a side window and monitors the temperature for regulation purposes. The emission from the tip is directed through an electromagnetic focussing lens and onto a specimen surface.