Digital Processing of Electron Energy Loss Spectra and Images

Processing in electron energy loss spectroscopy involves both data acquisition and analysis. The interface of an analytical electron microscope to a laboratory computer with a satellite microcomputer dedicated to data acquisition results in a system with a high degree of flexibility. In spectrum acquisition, channels may be selected around specific core edges, or dwell times may be varied continuously as a function of energy loss to reduce the dynamic range of the signal. Data transfer to the host computer allows further analysis such as the removal of plural scattering by spectral deconvolution. Elemental maps and line-scans can be recorded with real-time processing of energy loss data at each pixel. Images may be analyzed to provide quantitative information by means of pixel intensity histograms. If parameters for the background are stored at each pixel, the image data may sometimes be further processed to improve the signal-to-noise ratio