ABSTRACT
The spectral resolution in EELS is limited by the intrinsic energy spread of the electron source. The spatial resolution in scanning electron microscopy is limited by this spread via the chromatic aberration. The design of a Field Emission Gun monochromator with a resolution of 50 meV would be helpful. A new type of monochromator is introduced based on electrostatic deflectors. To minimize the brightness reduction of the electron source due to aberrations and Coulomb interactions, the beam potential, monochromator length and dispersion are balanced to get maximum current throughput.
