Outside links:
Microbeam Analysis Society
Microscopy Society of America

| Theory || Qualitative analysis || Quantitative analysis || Back-scattered and secondary electron imaging || Cathodoluminescence imaging |

Electron microprobe analysis depends on an electron beam that generates X-rays upon interaction with the specimen. The electron beam is generated by thermionic emission from a tungsten filament and accelarated in a potential difference of 5 to 30 kV. Beam electrons scatter elastically or inelastically upon encountering a specimen atom and loses a part or all of its energy, E0. High-angle elastic scattering with little energy loss contributes to the back-scattered electron signal used in compositional imaging, whereas, low-angle inelastic scattering with significant energy loss results in X-ray emission through inner-shell ionization and subsequent relaxation of the specimen atom. The electron beam must have sufficient energy to cause inner-shell ionization in the specimen atoms in order to generate X-rays.

The intensity of the X-rays are then measured with the Wavelength Dispersive Spectrometers (WDS). Data reduction converting measured X-ray intensities into elemental concentrations is handled by the computer software.

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Send comments to e-probe-www@mit.edu

(Last Revised 11/29/2007 by Nilanjan Chatterjee)