Influence of gun design on Coulomb interactions in a field emission gun

The authors investigate by simulation the Coulomb effects on brightness and energy spread for cold field emitters. At first, we show that brightness is ultimately limited by Coulomb interactions. The authors analyze the maximum attainable brightness for tip radii ranging from 1?nm to 1??m. Remarkably, the brightness of a tip of 1?nm is...

Brightness limitations of cold field emitters caused by Coulomb interactions

Emission theory predicts that high brightness cold field emitters can enhance imaging in the electron microscope. This (neglecting chromatic aberration) is because of the large (coherent) probe current available from a high brightness source and is based on theoretically determined values of reduced brightnesses up to 1014?A/(m2?sr?V). However,...