How do Geiger-Muller (GM) tubes detect radiation?

Geiger-Muller (GM) tubes detect radiation through the principle of gas ionization. When ionizing radiation passes through the gas in the tube, it interacts with the gas atoms, causing them to ionize. This means that some of the gas molecules lose electrons and become positively charged ions.

Once ionization occurs, free electrons are produced, which can then be accelerated towards the anode by the electric field established in the GM tube. As these electrons collide with more gas atoms, additional ionization events can occur, leading to an amplification effect. This cascade of ionization generates a measurable electrical pulse, which the GM tube detects and records as a count of radiation events.

The use of gas ionization makes GM tubes sensitive to various types of ionizing radiation, such as alpha particles, beta particles, and gamma rays. This detection method is effective because it allows for a quick response to radiation and provides a straightforward indication of radiation levels, making GM tubes a popular choice for radiation detection and monitoring in many fields.