Electron probe microanalyser



An Electron probe microanalyser (EPMA) is a modified form of electron microscope, in which the sample is bombarded with an electron beam and the resulting x-ray radiation is analysed (as opposed to the reflected electrons analysed in EM). An image of the sample is obtained, showing the chemical elements making up the sample at a resolution of 10-30 cubic microns or less. EPMAs can be used to analyse the distribution of the components making up alloys, distribution of trace elements in minerals, and other applications requiring microscopic determination of the composition of materials. The first EPMA was produced by David Wittry as part of his PhD thesis at Caltech, and was put into commercial production by the Cambridge Scientific Instrument Company under the brand name "Microscan".