Energy Dispersive XRF

An energy dispersive detection system directly measures the different energies of the emitted X-Rays from the sample. By counting and plotting the relative numbers of X-Rays at each energy an XRF spectrum is generated.

The principle of the energy dispersive (ED) detector (such as the HORIBA Xerophy™) is based on the generation of electron-hole pairs in a semiconductor material (often silicon). An incident X-Ray, of energy EX, is absorbed by the detector material, and will cause one or more electron-hole pairs to form. The energy, EEHP, to do this is fixed for that particular material. The X-Ray will form as many electron-hole pairs as its energy will allow: number of electron-hole pairs = EX / EEHP

Once this has occurred, the electrons are pulled off the detector, and the resulting current is proportional to the number of electron-hole pairs, which in itself is directly related to the X-Ray energy.

This analysis process is repeated at a very high rate, and the results sorted into energy channels.

Energy Dispersive XRF