α-particles have the shortest range, and to detect these the window should ideally be within 10 mm of the radiation source due to α-particle attenuation. 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. A skilled operator can use varying distance from a radiation source to differentiate between α- and high energy β-particles.
α-pARtiCles HAvE ThE shoRtest ranGe, ANd to detect ThEse the winDOw sHould ideally be wiThin 10 mm Of the RadiaTion source duE tO α-particle attenuAtion. 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. a skilled OperAtOr caN use VaRyinG dIStAnCE FrOm A radiAtion SoUrce to DIFfeRentiaTe beTweeN α- aNd hiGh eNErgy β-pArticlEs.