A fresh look at thermal field emission from tungsten tip

Abstract

Electron emission from clean tungsten tips has been investigated at different temperatures and applied electric field. Emission mechanism is analyzed on the basis of the Fowler-Nordheim (FN) model and a parameter extraction model based on elimination of field enhancement factor. The suggested extraction model of the physical and geometrical parameters is found fairly adequate to resolving the apparently confusing behavior of these parameters and shedding light on the emission mechanism. The observed linear FN plots at low temperatures confirm the predominating effect of the applied field on the electron emission. At elevated temperatures, emission is found to fall in the intermediate region between field emission and thermionic emission, therefore known as thermal-field emission. © TÜBITAK.