GM Counter Measuring Radiation

The GM counter is an instrument used to measure ionizing radiation and is commonly applied in fields such as radiation dosimetry, radiological protection, experimental physics, and the nuclear industry. It operates by detecting ionizing radiation using the ionization effect within a Geiger-Müller (GM) tube. A typical Geiger counter consists of two primary components: the Geiger-Muller tube and the processing and display electronics. The GM tube, filled with an inert gas such as helium, neon, or argon, becomes briefly conductive when a particle of radiation ionizes the gas. This ionization allows the tube to conduct an electrical charge, which is detected and recorded by the electronics. However, the GM tube has two main limitations. Because the output pulse from a GM tube is always of the same magnitude, regardless of the energy of the incident radiation, the GM counter cannot differentiate between radiation types. The other limitation is its inability to measure high radiation rates due to the tube's dead time. The dead time refers to a brief period after each ionization event when the tube becomes insensitive to additional radiation and any further incident radiation will not produce a count.