The YPS Schottky type thermal field emission sources are an excellent choice to replace used TFE sources in electron beam systems, including FESEM, SFEG-SEM, FETEM, EPMA, Auger and CD-SEM systems. The YPS sources are drop-in replacements for existing FEI and Denka style sources also known as 184 and 174 type suppressors. The YPS Schottky TFE source consists of a single crystal (100) tungsten wire with a very sharp tip including a zirconium reservoir around the the tungsten tip wire.

The tip is mounted on a hairpin filament which is used to mainatain the tip ate a temperature of around 1800K. This assembly is mounted in a cylindrical suppressor electrode with an aperture through which the sharp tip protudes. Electrons are emitted from the tip due to both thermal excitation and the electrical field at the tip. The YPS Schottky TFE source tip typically has a radius of 0.3µm and protrudes around 250µm to ensure high brigthness of the source.