Abstract
A brief description of a Wien filter energy-loss spectrometer design for the STEM is given. The performance limit of the device is about 80 meV resolution at 1 mrad semi-angle. At a 12.5 mrad semi-angle referred to the specimen, the total system delivers 0.35 eV resolution, limited mainly by the field emission tunneling width. Various experimental results are compared to results from other spectrometers.