How do Geiger-Muller counters indicate the presence of radiation?

Geiger-Muller counters are designed to detect ionizing radiation, such as alpha, beta, and gamma particles. When radiation interacts with the gas inside the Geiger tube, it ionizes the gas, leading to a cascade of ionization events. This process ultimately produces a pulse of current that the Geiger-Muller counter detects.

The indication of this pulse is most commonly given in the form of an audible click. Each click typically represents a detected particle or photon, allowing users to gauge the level of radiation in their environment audibly. This feature makes Geiger-Muller counters practical for real-time monitoring because the sound is instantaneous, providing immediate feedback on radiation levels.

Other methods of indicating radiation presence, such as emitting light or changing colors, are not standard functions of classic Geiger-Muller counters. While some modern radiation detection devices may use digital displays to show numerical values or visual indicators, the fundamental operation of traditional Geiger-Muller counters relies primarily on the distinct audible clicks to indicate radiation detection.