Zirconiated Tungsten (ZrOW) Thermal Field Emitters (TFE)
Thermal field emitters (TFE) are heated, like thermionic emitters, but are also electrochemically etched to have microscopically sharp tips, similar to the way cold field emitters are. Do to the sharpness of the emitter and its orientation to the suppressor during operation, a very high electric field is produced at the source tip. The lowering of the potential barrier by the field and the thermal energy supplied to the electrons through heating produce a source capable of operating in a non-crossover mode (or virtual source mode). As a result, unlike thermionic emitters, TFEs are not space charge limited and are orders of magnitude brighter than typical thermionic sources.
APT now offers zirconiated tungsten thermal field emitters (ZrOW TFE) , known colloquially as Schottky sources. The ZrOW TFE is the industry-standard emitter for electron beam applications requiring high brightness, improved spatial resolution, stable emission, and long life. Our ZrOW sources meet general OEM performance specifications and operational parameters and can be manufactured with custom end form (radius) geometries and any emitter base/suppressor configurations including FEI/Philips, Denka, Hitachi, JEOL, or custom configurations.
APT’s R&D team partners with customers to design cathodes customized to meet their needs. Contact us to speak with one of our specialists, explain your application use, and we can help guide you in the right direction.