Editing Geiger counter (section)

===Particle detection===
The first historical uses of the Geiger principle were to detect α- and β-particles, and the instrument is still used for this purpose today. For α-particles and low energy β-particles, the "end-window" type of a Geiger–Müller tube has to be used, as these particles have a limited range and are easily [[Stopping power (particle radiation)|stopped]] by a solid material. Therefore, the tube requires a window which is thin enough to allow as many as possible of these particles through to the fill gas. The window is usually made of [[mica]] with a density of about 1.5–2.0&nbsp;mg/cm<sup>2</sup>.<ref name="cent" />

α-particles have the shortest range, and to detect these the window should ideally be within 10&nbsp;mm of the radiation source due to α-particle [[attenuation]].<ref name="cent" /> However, the Geiger–Müller tube produces a pulse output which is the same magnitude for all detected radiation, so a Geiger counter with an end window tube cannot distinguish between α- and β-particles.<ref name="knoll" /> A skilled operator can use varying distance from a radiation source to differentiate between α- and high energy β-particles.

The "pancake" Geiger–Müller tube is a variant of the end-window probe, but designed with a larger detection area to make checking quicker. However, the pressure of the atmosphere against the low pressure of the fill gas limits the window size due to the limited strength of the window membrane.

Some β-particles can also be detected by a thin-walled "windowless" Geiger–Müller tube, which has no end-window, but allows high energy β-particles to pass through the tube walls. Although the tube walls have a greater stopping power than a thin end-window, they still allow these more energetic particles to reach the fill gas.<ref name="cent" />

End-window Geiger counters are still used as a general purpose, portable, [[radioactive contamination]] measurement and detection instrument, owing to their relatively low cost, robustness and relatively high detection efficiency; particularly with high energy β-particles.<ref name="knoll" /><ref>{{Cite news|url=https://xn--messgert-test-hfb.de/geigerzaehler/|title=G-M detector function and measuring methods|access-date=2017-03-07}}</ref> However, for discrimination between α- and β-particles or provision of particle energy information, [[scintillation counter]]s or [[proportional counter]]s should be used.<ref name = "ukhse"/> Those instrument types are manufactured with much larger detector areas, which means that checking for surface contamination is quicker than with a Geiger counter.