Typically a Geiger-Müller tube is used to detect

A Geiger-Müller (GM) tube is a gas-filled device used to detect and measure ionizing radiation. It works on the principle of ionization of gas molecules by incoming radiation, which triggers an avalanche of electrons and produces a measurable electrical pulse.

• Alpha (α) particles: Can be detected if the tube is equipped with a very thin mica window, as alpha particles have low penetrating power.
• Beta (β) particles: Easily detected as they can penetrate the tube's casing or window.
• Gamma (γ) rays: Detected through their interaction with the tube walls (producing secondary electrons), although the detection efficiency is lower compared to charged particles.

Because the GM tube responds to any ionizing event regardless of the type of radiation, it is typically used to detect all three: energetic α particles, β particles, and γ rays.