ABSTRACT
The point-spread function (PSF) representing chromatic blurring in an energy-filtered TEM image is an arctan×hyperbolic or a hyperbolic function, depending on the specimen thickness. The radius containing 50% of the electrons is typically 10% - 30% of the total radius, and can be even less in the case of spherical aberration. The same PSF describes the current density distribution in an SEM probe, particularly at low incident energy where chromatic aberration predominates.
