Geiger discharge

A Geiger discharge is a phenomenon that occurs within a Geiger-Müller counter, a type of ionization chamber used for detecting radiation. When a charged particle passes through the gas inside the detector, it causes ionization, creating ion pairs.12

In a Geiger-Müller counter, the conditions are set up so that each initial avalanche of ionization triggers more avalanches, leading to an uncontrolled spread of ionization throughout the detector. This is known as a Geiger discharge. The discharge is eventually stopped by a buildup of positive ions around the central anode wire, which temporarily reduces the electric field and prevents further avalanches. This process generates a large electrical pulse, making Geiger counters effective for counting individual radiation particles, though the pulse size doesn't indicate the energy of the radiation.1