ABSTRACT
A simple new method is described to obtain long camera lengths and high angular resolution. The specimen is raised above the image plane so that diffracted images of the convergent probe (a ‘diffraction pattern’) are seen in image plane. The angular resolution in this pattern depends on the probe size and specimen defocus but can be as high as 2 μrad making the new method extremely useful for studying small q features in angle-resolved energy loss spectra. Using a narrow slit at the entrance aperture to a Gatan Imaging Filter (GIF) it was possible to form ω-q patterns with very high angular resolution. Spectra from diamond are used as examples to show the potential worth of this new method.
