Editing X-ray fluorescence (section)

===Detection===
[[File:20180221-OSEC-LSC-0055 (39518128545).jpg|thumb|A portable XRF analyzer using a [[silicon drift detector]]]]
In energy-dispersive analysis, dispersion and detection are a single operation, as already mentioned above. [[Proportional counter]]s or various types of solid-state detectors ([[PIN diode]], Si(Li), Ge(Li), [[silicon drift detector]] SDD) are used. They all share the same detection principle: An incoming X-ray [[photon]] ionizes a large number of detector atoms with the amount of charge produced being proportional to the energy of the incoming photon. The charge is then collected and the process repeats itself for the next photon. Detector speed is obviously critical, as all charge carriers measured have to come from the same photon to measure the photon energy correctly (peak length discrimination is used to eliminate events that seem to have been produced by two X-ray photons arriving almost simultaneously). The spectrum is then built up by dividing the energy spectrum into discrete bins and counting the number of pulses registered within each energy bin. EDXRF detector types vary in resolution, speed and the means of cooling (a low number of free charge carriers is critical in the solid state detectors): proportional counters with resolutions of several hundred eV cover the low end of the performance spectrum, followed by [[PIN diode]] detectors, while the Si(Li), Ge(Li) and SDDs occupy the high end of the performance scale.

In wavelength-dispersive analysis, the single-wavelength radiation produced by the monochromator is passed into a chamber containing a gas that is ionized by the X-ray photons. A central electrode is charged at (typically) +1700 V with respect to the conducting chamber walls, and each photon triggers a pulse-like cascade of current across this field. The signal is amplified and transformed into an accumulating digital count. These counts are then processed to obtain analytical data.