Secondary emission

Secondary emission is in physics a name for the induced by primary particles or radiation emission of secondary particles or radiation when impinging on surfaces or passing-through materials. A trigger for the secondary emission electrons are commonly, ions, or high energy radiation (X-ray or gamma radiation). When it comes to electrons at the secondary particles, one speaks of a secondary electron emission, is it to ions, one speaks of a secondary ion emission.

The energy distribution and emission rate of the secondary electrons allows to draw conclusions on the surface conditions and the material properties. This is utilized in the secondary electron, which is the standard mode of operation the scanning electron microscope. The sample is bombarded with an electron beam and the emitted secondary electrons are detected here.

A secondary electron multiplier takes advantage of the formation of secondary electrons to amplify very small currents and thus to make better detectable. The best known design of such multiplier is the photomultiplier.

In a secondary ion mass spectrometer, the generation of secondary ions by primary ions used for surface analysis.