The Geiger-Müller tube is filled with an inert gas such as helium, neon, or argon at low pressure, which briefly conducts electrical charge when a particle or photon of incident radiation makes the gas conductive by ionization.
The Geiger-Müller tube is filled with an inert gas such as helium, neon, or argon at low pressure, to which a high voltage is applied. The tube briefly conducts electrical charge when a particle or photon of incident radiation makes the gas conductive by ionization.